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Sample records for wimp detection event

  1. The Diurnal Variation of the Wimp Detection Event Rates in Directional Experiments

    CERN Document Server

    Vergados, J D

    2009-01-01

    The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Modern particle theories naturally provide viable cold dark matter candidates with masses in the GeV-TeV region. Supersymmetry provides the lightest supersymmetric particle (LSP), theories in extra dimensions supply the lightest Kaluza-Klein particle (LKP) etc. The nature of dark matter can only be unraveled only by its direct detection in the laboratory. All such candidates will be called WIMPs (Weakly Interacting Massive Particles). In any case the direct dark matter search, which amounts to detecting the recoiling nucleus, following its collision with WIMP, is central to particle physics and cosmology. In this work we briefly review the theoretical elements relevant to the direct dark matter detection experiments, paying particular attention to directional experiments. i.e experiments in which, not only the energy but the direction of the recoiling nucleus is ob...

  2. Working Group Report: WIMP Dark Matter Direct Detection

    International Nuclear Information System (INIS)

    Cushman, P.; Galbiati, C.; McKinsey, D. N.; Robertson, H.; Tait, T. M.P.

    2013-01-01

    As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The charge to CF1 was (a) to summarize the current status and projected sensitivity of WIMP direct detection experiments worldwide, (b) motivate WIMP dark matter searches over a broad parameter space by examining a spectrum of WIMP models, (c) establish a community consensus on the type of experimental program required to explore that parameter space, and (d) identify the common infrastructure required to practically meet those goals.

  3. Working Group Report: WIMP Dark Matter Direct Detection

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, P.; Galbiati, C.; McKinsey, D. N.; Robertson, H.; Tait, T. M.P.

    2013-10-30

    As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The charge to CF1 was (a) to summarize the current status and projected sensitivity of WIMP direct detection experiments worldwide, (b) motivate WIMP dark matter searches over a broad parameter space by examining a spectrum of WIMP models, (c) establish a community consensus on the type of experimental program required to explore that parameter space, and (d) identify the common infrastructure required to practically meet those goals.

  4. Model-independent determination of the WIMP mass from direct dark matter detection data

    International Nuclear Information System (INIS)

    Drees, Manuel; Shan, Chung-Lin

    2008-01-01

    Weakly interacting massive particles (WIMPs) are one of the leading candidates for dark matter. We develop a model-independent method for determining the mass m χ of the WIMP by using data (i.e. measured recoil energies) of direct detection experiments. Our method is independent of the as yet unknown WIMP density near the Earth, of the form of the WIMP velocity distribution, as well as of the WIMP–nucleus cross section. However, it requires positive signals from at least two detectors with different target nuclei. In a background-free environment, m χ ∼50 GeV could in principle be determined with an error of ∼35% with only 2 × 50 events; in practice, upper and lower limits on the recoil energy of signal events, imposed to reduce backgrounds, can increase the error. The method also loses precision if m χ significantly exceeds the mass of the heaviest target nucleus used

  5. Understanding WIMP-baryon interactions with direct detection: a roadmap

    International Nuclear Information System (INIS)

    Gluscevic, Vera; Peter, Annika H.G.

    2014-01-01

    We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection

  6. WIMP detection and slow ion dynamics in carbon nanotube arrays

    CERN Document Server

    Cavoto, G.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-06-24

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with ...

  7. WIMP detection and slow ion dynamics in carbon nanotube arrays

    International Nuclear Information System (INIS)

    Cavoto, G.; Cirillo, E.N.M.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-01-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (∼ 11 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency. (orig.)

  8. WIMP detection and slow ion dynamics in carbon nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Cavoto, G. [INFN Sezione di Roma, Rome (Italy); Cirillo, E.N.M. [Sapienza Universita di Roma, Dipartimento SBAI, Rome (Italy); Cocina, F. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Ferretti, J. [Sapienza Universita di Roma, Dipartimento di Fisica (Italy); INFN Sezione di Roma, Rome (Italy); Polosa, A.D. [Sapienza Universita di Roma, Dipartimento di Fisica (Italy); CERN, Theory Division, Geneva (Switzerland); INFN Sezione di Roma, Rome (Italy)

    2016-06-15

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (∼ 11 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency. (orig.)

  9. WIMP detection and slow ion dynamics in carbon nanotube arrays.

    Science.gov (United States)

    Cavoto, G; Cirillo, E N M; Cocina, F; Ferretti, J; Polosa, A D

    2016-01-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs ([Formula: see text] GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency.

  10. Readout technologies for directional WIMP Dark Matter detection

    International Nuclear Information System (INIS)

    Battat, J.B.R.; Irastorza, I.G.; Aleksandrov, A.; Asada, T.; Baracchini, E.; Billard, J.; Bosson, G.; Bourrion, O.; Bouvier, J.; Buonaura, A.; Burdge, K.; Cebrián, S.

    2016-01-01

    The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.

  11. Halo-independent analysis of direct detection data for light WIMPs

    International Nuclear Information System (INIS)

    Nobile, Eugenio Del; Gelmini, Graciela B.; Huh, Ji-Haeng; Gondolo, Paolo

    2013-01-01

    We present a halo-independent analysis of direct detection data on ''light WIMPs'', i.e. weakly interacting massive particles with mass close to or below 10 GeV/c 2 . We include new results from silicon CDMS detectors (bounds and excess events), the latest CoGeNT acceptances, and recent measurements of low sodium quenching factors in NaI crystals. We focus on light WIMPs with spin-independent isospin-conserving and isospin-violating interactions with nucleons. For these dark matter candidates we find that a low quenching factor would make the DAMA modulation incompatible with a reasonable escape velocity for the dark matter halo, and that the tension among experimental data tightens in both the isospin-conserving and isospin-violating scenarios. We also find that a new although milder tension appears between the CoGeNT and DAMA annual modulations on one side and the silicon excess events on the other, in that it seems difficult to interpret them as the modulated and unmodulated aspects of the same WIMP dark matter signal

  12. Direct detection of WIMPs: implications of a self-consistent truncated isothermal model of the Milky Way's dark matter halo

    Science.gov (United States)

    Chaudhury, Soumini; Bhattacharjee, Pijushpani; Cowsik, Ramanath

    2010-09-01

    Direct detection of Weakly Interacting Massive Particle (WIMP) candidates of Dark Matter (DM) is studied within the context of a self-consistent truncated isothermal model of the finite-size dark halo of the Galaxy. The halo model, based on the ``King model'' of the phase space distribution function of collisionless DM particles, takes into account the modifications of the phase-space structure of the halo due to the gravitational influence of the observed visible matter in a self-consistent manner. The parameters of the halo model are determined by a fit to a recently determined circular rotation curve of the Galaxy that extends up to ~ 60 kpc. Unlike in the Standard Halo Model (SHM) customarily used in the analysis of the results of WIMP direct detection experiments, the velocity distribution of the WIMPs in our model is non-Maxwellian with a cut-off at a maximum velocity that is self-consistently determined by the model itself. For our halo model that provides the best fit to the rotation curve data, the 90% C.L. upper limit on the WIMP-nucleon spin-independent cross section from the recent results of the CDMS-II experiment, for example, is ~ 5.3 × 10-8 pb at a WIMP mass of ~ 71 GeV. We also find, using the original 2-bin annual modulation amplitude data on the nuclear recoil event rate seen in the DAMA experiment, that there exists a range of small WIMP masses, typically ~ 2-16 GeV, within which DAMA collaboration's claimed annual modulation signal purportedly due to WIMPs is compatible with the null results of other experiments. These results, based as they are on a self-consistent model of the dark matter halo of the Galaxy, strengthen the possibility of low-mass (lsim10 GeV) WIMPs as a candidate for dark matter as indicated by several earlier studies performed within the context of the SHM. A more rigorous analysis using DAMA bins over smaller intervals should be able to better constrain the ``DAMA regions'' in the WIMP parameter space within the context of

  13. The WIMP Forest: Indirect Detection of a Chiral Square

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Gianfranco; Jackson, C.B.; Shaughnessy, Gabe; Tait, Tim M.P.; Vallinotto, Alberto

    2009-04-01

    The spectrum of photons arising from WIMP annihilation carries a detailed imprint of the structure of the dark sector. In particular, loop-level annihilations into a photon and another boson can in principle lead to a series of lines (a WIMP forest) at energies up to the WIMP mass. A specific model which illustrates this feature nicely is a theory of two universal extra dimensions compactified on a chiral square. Aside from the continuum emission, which is a generic prediction of most dark matter candidates, we find a 'forest' of prominent annihilation lines that, after convolution with the angular resolution of current experiments, leads to a distinctive (2-bump plus continuum) spectrum, which may be visible in the near future with the Fermi Gamma-Ray Space Telescope (formerly known as GLAST).

  14. Beyond WIMP: From Theory to Detection of Sub-GeV Dark Matter

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The existence of dark matter has been well established with overwhelming evidence, but its particle identity is still unknown. For more than three decades, significant theoretical and experimental efforts have been directed towards the search for a Weakly Interacting Massive Particle (WIMP), often overlooking other possibilities. The lack of an unambiguous positive WIMP signal, at both indirect- and direct-detection experiments and at the LHC, stresses the need to expand dark matter research into additional theoretical scenarios and, more importantly, to develop new experimental capabilities that go beyond the limitations of WIMP detection. In this talk I will discuss new theoretical ideas and experimental avenues for searching for light, sub-GeV dark matter. Some emphasis will be given to direct detection experiments, where several new strategies to directly detect dark matter particles with MeV to GeV mass, far below standard direct detection capabilities, are developed.

  15. Accurate calculations of the WIMP halo around the Sun and prospects for its gamma-ray detection

    International Nuclear Information System (INIS)

    Sivertsson, Sofia; Edsjoe, Joakim

    2010-01-01

    Galactic weakly interacting massive particles (WIMPs) may scatter off solar nuclei to orbits gravitationally bound to the Sun. Once bound, the WIMPs continue to lose energy by repeated scatters in the Sun, eventually leading to complete entrapment in the solar interior. While the density of the bound population is highest at the center of the Sun, the only observable signature of WIMP annihilations inside the Sun is neutrinos. It has been previously suggested that although the density of WIMPs just outside the Sun is lower than deep inside, gamma rays from WIMP annihilation just outside the surface of the Sun, in the so-called WIMP halo around the Sun, may be more easily detected. We here revisit this problem using detailed Monte Carlo simulations and detailed composition and structure information about the Sun to estimate the size of the gamma-ray flux. Compared to earlier simpler estimates, we find that the gamma-ray flux from WIMP annihilations in the solar WIMP halo would be negligible; no current or planned detectors would be able to detect this flux.

  16. Direct detection of dark matter with the EDELWEISS-III experiment: signals induced by charge trapping, data analysis and characterization of cryogenic detector sensitivity to low-mass WIMPs

    International Nuclear Information System (INIS)

    Arnaud, Quentin

    2015-01-01

    The EDELWEISS-III experiment is dedicated to direct dark matter searches aiming at detecting WIMPS. These massive particles should account for more than 80% of the mass of the Universe and be detectable through their elastic scattering on nuclei constituting the absorber of a detector. As the expected WIMP event rate is extremely low ( 20 GeV). Finally, a study dedicated to the optimization of solid cryogenic detectors to low mass WIMP searches is presented. This study is performed on simulated data using a statistical test based on a profiled likelihood ratio that allows for statistical background subtraction and spectral shape discrimination. This study combined with results from Run308, has lead the EDELWEISS experiment to favor low mass WIMP searches ( [fr

  17. A Study of Nuclear Recoils in Liquid Argon Time Projection Chamber for the Direct Detection of WIMP Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Huajie [Princeton Univ., NJ (United States)

    2014-11-01

    Robust results of WIMP direct detection experiments depend on rm understandings of nuclear recoils in the detector media. This thesis documents the most comprehensive study to date on nuclear recoils in liquid argon - a strong candidate for the next generation multi-ton scale WIMP detectors. This study investigates both the energy partition from nuclear recoil energy to secondary modes (scintillation and ionization) and the pulse shape characteristics of scintillation from nuclear recoils.

  18. Detection of WIMPs in the Edelweiss experiment. Study of the radioactive background noise and measurements with bolometers; Recherche des wimp's du halo galactique dans l'experience edelweiss: etude du bas bruit radioactif et mesures a l'aide de bolometres a double detection ionisation/chaleur

    Energy Technology Data Exchange (ETDEWEB)

    Miramonti, L. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-11-01

    This thesis is dedicated to the detection of black matter in the form of WIMPs (weakly interacting massive particle). The characteristics of the interaction of WIMPs with matter are recalled. The very low number of expected events (<1 event/day.Kg) implies a radioactive background noise as weak as possible, furthermore the exponential decrease of the interacting rate with increasing energy calls for detectors with very low thresholds. Bolometers present advantages in WIMPs detection: i) very good resolution and very low thresholds, ii) very broad range of materials that can be used as absorber, the only requirements are: a crystal structure, to be a diamagnetic isolator and to have a convenient Debye temperature, iii) the possibility of detecting ionizing or non-ionizing particles, iv) the possibility of identifying the incident particle by measuring both temperature and another parameter such as ionization or scintillation, and v) the possibility of localizing the interaction inside the absorber by detecting ballistic phonons. The problematic of radioactive background noise is presented and the answers to the different sources (cosmic radiation,natural and artificial radioactivity) generating the background noise are examined. The materials used in the building of the detector and cryostat must be carefully chosen, they should be as little radioactive as possible. The test benches used to select materials for the Edelweiss experiment are described. The first measurements concerning the detectors Ge-4 and Ge-7 are presented. (A.C.)

  19. Constraints on low-mass WIMPs from the EDELWEISS-III dark matter search

    Energy Technology Data Exchange (ETDEWEB)

    Armengaud, E.; De Boissière, T. [CEA Saclay, DSM/IRFU, Gif-sur-Yvette Cedex, 91191 France (France); Arnaud, Q.; Augier, C.; Benoît, A.; Billard, J.; Cazes, A.; Charlieux, F. [Institut de Physique Nucléaire de Lyon-UCBL, IN2P3-CNRS, 4 rue Enrico Fermi, Villeurbanne Cedex, 69622 France (France); Benoît, A.; Bres, G.; Camus, P. [Institut Néel, CNRS/UJF, 25 rue des Martyrs, BP 166, Grenoble, 38042 France (France); Bergé, L.; Broniatowski, A.; Chapellier, M.; Dumoulin, L. [CSNSM, Université Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, 91405 France (France); Bergmann, T. [Karlsruher Institut für Technologie, Institut für Prozessdatenverarbeitung und Elektronik, Postfach 3640, Karlsruhe, 76021 Germany (Germany); Blümer, J. [Karlsruher Institut für Technologie, Institut für Experimentelle Kernphysik, Gaedestr. 1, Karlsruhe, 76128 Germany (Germany); Brudanin, V.; Filosofov, D. [JINR, Laboratory of Nuclear Problems, Joliot-Curie 6, Dubna, Moscow Region, 141980 Russian Federation (Russian Federation); Eitel, K., E-mail: eric.armengaud@cea.fr [Karlsruher Institut für Technologie, Institut für Kernphysik, Postfach 3640, Karlsruhe, 76021 Germany (Germany); and others

    2016-05-01

    We present the results of a search for elastic scattering from galactic dark matter in the form of Weakly Interacting Massive Particles (WIMPs) in the 4–30 GeV/ c {sup 2} mass range. We make use of a 582 kg-day fiducial exposure from an array of 800 g Germanium bolometers equipped with a set of interleaved electrodes with full surface coverage. We searched specifically for ∼ 2.5–20 keV nuclear recoils inside the detector fiducial volume. As an illustration the number of observed events in the search for 5 (resp. 20) GeV/ c {sup 2} WIMPs are 9 (resp. 4), compared to an expected background of 6.1 (resp. 1.4). A 90% CL limit of 4.3 × 10{sup −40} cm{sup 2} (resp. 9.4 × 10{sup −44} cm{sup 2}) is set on the spin-independent WIMP-nucleon scattering cross-section for 5 (resp. 20) GeV/ c {sup 2} WIMPs. This result represents a 41-fold improvement with respect to the previous EDELWEISS-II low-mass WIMP search for 7 GeV/ c {sup 2} WIMPs. The derived constraint is in tension with hints of WIMP signals from some recent experiments, thus confirming results obtained with different detection techniques.

  20. Bolometer's development for the detection of dark matter; Instrumentation autour de bolometres pour la recherche de matiere sombre WIMPs

    Energy Technology Data Exchange (ETDEWEB)

    Yvon, D

    2000-06-01

    The author reviews his contributions to the use of bolometers (cryogenic detectors) for the detection of wimps (weakly interactive massive particles). Wimps are detected through their elastic scattering on the nuclei of the detector, a heat signal, luminescence or ionization can be simultaneously detected (at least 2 signals are necessary to discard photon interactions). Bolometers operate at low temperatures (< 50 mK) so they allow very low detection threshold and resolution (< keV) with a full energy conversion for recoiling nuclei. In Saclay the technology of bolometers based on simultaneous detection of heat and ionisation has been developed and improvements have been studied (NbSi thin films bolometers). The first results obtained in the framework of the Edelweiss collaboration are presented. Other developments based on infra-red bolometry (Planck surveyor and Archeops projects) are briefly described. In an appendix the operating principle of a bolometer is presented. (A.C.)

  1. The Fraternal WIMP Miracle

    CERN Document Server

    Craig, Nathaniel

    2015-01-01

    We identify and analyze thermal dark matter candidates in the fraternal twin Higgs model and its generalizations. The relic abundance of fraternal twin dark matter is set by twin weak interactions, with a scale tightly tied to the weak scale of the Standard Model by naturalness considerations. As such, the dark matter candidates benefit from a "fraternal WIMP miracle," reproducing the observed dark matter abundance for dark matter masses between 50 and 150 GeV. However, the couplings dominantly responsible for dark matter annihilation do not lead to interactions with the visible sector. The direct detection rate is instead set via fermionic Higgs portal interactions, which are likewise constrained by naturalness considerations but parametrically weaker than those leading to dark matter annihilation. The predicted direct detection cross section is close to current LUX bounds and presents an opportunity for the next generation of direct detection experiments.

  2. Optimization of the energy resolution and of the radioactive background rejection for ionization-heat detectors equipped with thermometric thin films for the direct WIMPs detection

    International Nuclear Information System (INIS)

    Dolgorouky, Y.W.

    2008-09-01

    The EDELWEISS experiment aims at the direct detection of WIMPs as possible candidates for dark matter. It uses heat-and-ionization detectors that can discriminate these particles from the radioactive background. To date, this method is limited by events with incomplete charge collection that occur just beneath the detectors electrodes. In order to identify and reject these undesirable events, we have developed detectors equipped with thin films used both as thermometers - and hence sensitive to the transient athermal regime - and as electrodes for the charge collection. This thesis focuses on the optimization of such thin films regarding surface events rejection and on the modelling of the physical processes enabling this identification. The optimization must both maximize the fiducial volume and conserve an energy resolution such that the recoil energy threshold is of the order of 30 keV. Our work explores four generations of detectors each of which corresponds to successive evolutions in their conception. In all cases, the electrode-thermometer is an amorphous Anderson insulator NbSi thin film polarized by two interleaved comb-shaped niobium electrodes. In spite of constant progress in the successive detectors performances, the latest generation does not display the performances required for the EDELWEISS II experiment. Our work has shown the difficulty of the transient thermal signal modelling due to the complex contribution of the charge collection. This works has lead to new ideas regarding the detectors configuration, so that the athermal regime can be optimized to enhance both the rejection capability and the resolution. (author)

  3. TREX-DM: a low-background Micromegas-based TPC for low-mass WIMP detection

    Energy Technology Data Exchange (ETDEWEB)

    Iguaz, F.J.; Garza, J.G.; Castel, J.F.; Cebrian, S.; Dafni, T.; Garcia, J.A.; Irastorza, I.G.; Lagraba, A.; Luzon, G.; Peiro, A. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Aznar, F. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Universidad de Zaragoza, Centro Universitario de la Defensa, Zaragoza (Spain)

    2016-10-15

    If Dark Matter is made of Weakly Interacting Massive Particles (WIMPs) with masses below ∝20 GeV, the corresponding nuclear recoils in mainstream WIMP experiments are of energies too close, or below, the experimental threshold. Gas Time Projection Chambers (TPCs) can be operated with a variety of target elements, offer good tracking capabilities and, on account of the amplification in gas, very low thresholds are achievable. Recent advances in electronics and in novel radiopure TPC readouts, especially micro-mesh gas structure (Micromegas), are improving the scalability and low-background prospects of gaseous TPCs. Here we present TREX-DM, a prototype to test the concept of a Micromegas-based TPC to search for low-mass WIMPs. The detector is designed to host an active mass of ∝0.300 kg of Ar at 10 bar, or alternatively ∝0.160 kg of Ne at 10 bar, with an energy threshold below 0.4 keVee, and is fully built with radiopure materials. We will describe the detector in detail, the results from the commissioning phase on surface, as well as a preliminary background model. The anticipated sensitivity of this technique may go beyond current experimental limits for WIMPs of masses of 2-8 GeV. (orig.)

  4. The capability to detect wimps with a high energy neutrino telescope

    International Nuclear Information System (INIS)

    Blondeau, F.

    1998-05-01

    We studied the potential of the proposed ANTARES undersea neutrino telescope to detect muons coming from from neutralinos annihilating at the center of the Earth. First results show that the full 1 km 3 -scale detector can indicate, after a few years of operation, if there are indeed neutralinos trapped at the core of celestial bodies, as expected are the major form of dark matter in our galaxy. (author)

  5. Anisotropic dark matter distribution functions and impact on WIMP direct detection

    International Nuclear Information System (INIS)

    Bozorgnia, Nassim; Schwetz, Thomas; Catena, Riccardo

    2013-01-01

    Dark matter N-body simulations suggest that the velocity distribution of dark matter is anisotropic. In this work we employ a mass model for the Milky Way whose parameters are determined from a fit to kinematical data. Then we adopt an ansatz for the dark matter phase space distribution which allows to construct self-consistent halo models which feature a degree of anisotropy as a function of the radius such as suggested by the simulations. The resulting velocity distributions are then used for an analysis of current data from dark matter direct detection experiments. We find that velocity distributions which are radially biased at large galactocentric distances (up to the virial radius) lead to an increased high velocity tail of the local dark matter distribution. This affects the interpretation of data from direct detection experiments, especially for dark matter masses around 10 GeV, since in this region the high velocity tail is sampled. We find that the allowed regions in the dark matter mass-cross section plane as indicated by possible hints for a dark matter signal reported by several experiments as well as conflicting exclusion limits from other experiments shift in a similar way when the halo model is varied. Hence, it is not possible to improve the consistency of the data by referring to anisotropic halo models of the type considered in this work

  6. Higgs dark matter in UEDs: A good WIMP with bad detection prospects

    International Nuclear Information System (INIS)

    Melbéus, Henrik; Merle, Alexander; Ohlsson, Tommy

    2012-01-01

    We study the first Kaluza-Klein excitation of the Higgs boson in universal extra dimensions as a dark matter candidate. The first-level Higgs boson could be the lightest Kaluza-Klein particle, which is stable due to the conservation of Kaluza-Klein parity, in non-minimal models where boundary localized terms modify the mass spectrum. We calculate the relic abundance and find that it agrees with the observed dark matter density if the mass of the first-level Higgs boson is slightly above 2 TeV, not considering coannihilations and assuming no relative mass splitting among the first-level Kaluza-Klein modes. In the case of coannihilations and a non-zero mass splitting, the mass of the first-level Higgs boson can range from 1 TeV to 4 TeV. We study also the prospects for detection of this dark matter candidate in direct as well as indirect detection experiments. Although the first-level Higgs boson is a typical weakly interacting massive particle, an observation in any of the conventional experiments is very challenging.

  7. The local dark matter phase-space density and impact on WIMP direct detection

    International Nuclear Information System (INIS)

    Catena, Riccardo; Ullio, Piero

    2012-01-01

    We present a new determination of the local dark matter phase-space density. This result is obtained implementing, in the limit of isotropic velocity distribution and spherical symmetry, Eddington's inversion formula, which links univocally the dark matter distribution function to the density profile, and applying, within a Bayesian framework, a Markov Chain Monte Carlo algorithm to sample mass models for the Milky Way against a broad and variegated sample of dynamical constraints. We consider three possible choices for the dark matter density profile, namely the Einasto, NFW and Burkert profiles, finding that the velocity dispersion, which characterizes the width in the distribution, tends to be larger for the Burkert case, while the escape velocity depends very weakly on the profile, with the mean value we obtain being in very good agreement with estimates from stellar kinematics. The derived dark matter phase-space densities differ significantly — most dramatically in the high velocity tails — from the model usually taken as a reference in dark matter detection studies, a Maxwell-Boltzmann distribution with velocity dispersion fixed in terms of the local circular velocity and with a sharp truncation at a given value of the escape velocity. We discuss the impact of astrophysical uncertainties on dark matter scattering rates and direct detection exclusion limits, considering a few sample cases and showing that the most sensitive ones are those for light dark matter particles and for particles scattering inelastically. As a general trend, regardless of the assumed profile, when adopting a self-consistent phase-space density, we find that rates are larger, and hence exclusion limits stronger, than with the standard Maxwell-Boltzmann approximation. Tools for applying our result on the local dark matter phase-space density to other dark matter candidates or experimental setups are provided

  8. Wimps and stellar structure

    International Nuclear Information System (INIS)

    Bouquet, A.; Salati, P.

    1988-01-01

    We present the results of an analytic approximation to compute the effects of WIMPs on stellar structures in a self-consistent way. We examine in particular the case of the Sun and of horizontal branch stars

  9. Optimization of the energy resolution and of the radioactive background rejection for ionization-heat detectors equipped with thermometric thin films for the direct WIMPs detection; Optimisation du pouvoir de resolution et du rejet du fond radioactif de detecteurs ionisation-chaleur equipes de couches minces thermometriques pour la detection directe de WIMPS

    Energy Technology Data Exchange (ETDEWEB)

    Dolgorouky, Y.W.

    2008-09-15

    The EDELWEISS experiment aims at the direct detection of WIMPs as possible candidates for dark matter. It uses heat-and-ionization detectors that can discriminate these particles from the radioactive background. To date, this method is limited by events with incomplete charge collection that occur just beneath the detectors electrodes. In order to identify and reject these undesirable events, we have developed detectors equipped with thin films used both as thermometers - and hence sensitive to the transient athermal regime - and as electrodes for the charge collection. This thesis focuses on the optimization of such thin films regarding surface events rejection and on the modelling of the physical processes enabling this identification. The optimization must both maximize the fiducial volume and conserve an energy resolution such that the recoil energy threshold is of the order of 30 keV. Our work explores four generations of detectors each of which corresponds to successive evolutions in their conception. In all cases, the electrode-thermometer is an amorphous Anderson insulator NbSi thin film polarized by two interleaved comb-shaped niobium electrodes. In spite of constant progress in the successive detectors performances, the latest generation does not display the performances required for the EDELWEISS II experiment. Our work has shown the difficulty of the transient thermal signal modelling due to the complex contribution of the charge collection. This works has lead to new ideas regarding the detectors configuration, so that the athermal regime can be optimized to enhance both the rejection capability and the resolution. (author)

  10. 6th Patras workshop on axions, WIMPs and WISPs (PATRAS 2010). Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Baudis, Laura; Schumann, Marc (eds.)

    2010-11-15

    The following topics were dealt with: Axions, WIMPs, WISPs, and neutrinos in the universe, laboratory experimental searching for WISPs, astrophysical experimental searching for WISPs, direct and indirect detection of WIMPs, new ideas and developments, visions, large laboratories. (HSI)

  11. 6th Patras workshop on axions, WIMPs and WISPs (PATRAS 2010). Proceedings

    International Nuclear Information System (INIS)

    Baudis, Laura; Schumann, Marc

    2010-11-01

    The following topics were dealt with: Axions, WIMPs, WISPs, and neutrinos in the universe, laboratory experimental searching for WISPs, astrophysical experimental searching for WISPs, direct and indirect detection of WIMPs, new ideas and developments, visions, large laboratories. (HSI)

  12. Detection of anomalous events

    Science.gov (United States)

    Ferragut, Erik M.; Laska, Jason A.; Bridges, Robert A.

    2016-06-07

    A system is described for receiving a stream of events and scoring the events based on anomalousness and maliciousness (or other classification). The system can include a plurality of anomaly detectors that together implement an algorithm to identify low-probability events and detect atypical traffic patterns. The anomaly detector provides for comparability of disparate sources of data (e.g., network flow data and firewall logs.) Additionally, the anomaly detector allows for regulatability, meaning that the algorithm can be user configurable to adjust a number of false alerts. The anomaly detector can be used for a variety of probability density functions, including normal Gaussian distributions, irregular distributions, as well as functions associated with continuous or discrete variables.

  13. To catch a WIMP

    International Nuclear Information System (INIS)

    Goldsmith, Donald.

    1995-01-01

    In the rush to account for the missing ''dark matter'' in the universe, many teams of cosmologists are setting up experiments to prove the existence of a hypothetical form of matter called weakly interacting massive particles, or WIMPS. The innovative research ideas developed by these teams are described and compared briefly. (UK)

  14. Exclusion limits on the WIMP nucleon elastic scattering cross-section from the Cryogenic Dark Matter Search

    Energy Technology Data Exchange (ETDEWEB)

    Golwala, Sunil Ramanlal [UC, Berkeley

    2000-01-01

    Extensive evidence indicates that a large fraction of the matter in the universe is nonluminous, nonbaryonic, and “cold” — nonrelativistic at the time matter began to dominate the energy density of the universe. Weakly Interacting Massive Particles (WIMPs) are an excellent candidate for nonbaryonic, cold dark matter. Minimal supersymmetry provides a natural WIMP candidate in the form of the lightest superpartner, with a typical mass Mδ ~ 100 GeV c-2 . WIMPs are expected to have collapsed into a roughly isothermal, spherical halo within which the visible portion of our galaxy resides. They would scatter off nuclei via the weak interaction, potentially allowingtheir direct detection. The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for WIMPs via their elastic-scatteringinteractions with nuclei while discriminatingagainst interactions of background particles. The former yield nuclear recoils while the latter produce electron recoils. The ionization yield (the ratio of ionization production to recoil energy in a semiconductor) of a particle interaction differs greatly for nuclear and electron recoils. CDMS detectors measure phonon and electron-hole-pair production to determine recoil energy and ionization yield for each event and thereby discriminate nuclear recoils from electron recoils. This dissertation reports new limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV c-2 WIMP mass and, at > 75% CL, the entire 3σ allowed region for the WIMP signal reported by the DAMA experiment. The experimental apparatus, detector performance, and data analysis are fully described.

  15. The WIMP Paradigm: Current Status

    International Nuclear Information System (INIS)

    Feng, Jonathan

    2011-01-01

    The WIMP paradigm is the glue that joins together much of the high energy and cosmic frontiers. It postulates that most of the matter in the Universe is made of weakly-interacting massive particles, with implications for a broad range of experiments and observations. I will review the WIMP paradigm's underlying motivations, its current status in view of rapid experimental progress on several fronts, and recent theoretical variations on the WIMP paradigm theme.

  16. Planck-scale effects on WIMP dark matter

    Directory of Open Access Journals (Sweden)

    Sofiane M Boucenna

    2014-01-01

    Full Text Available There exists a widely known conjecture that gravitational effects violate global symmetries. We study the effect of global-symmetry violating higher-dimension operators induced by Planck-scale physics on the properties of WIMP dark matter. Using an effective description, we show that the lifetime of the WIMP dark matter candidate can satisfy cosmological bounds under reasonable assumptions regarding the strength of the dimension-five operators. On the other hand, the indirect WIMP dark matter detection signal is significantly enhanced due to new decay channels.

  17. Optimizing EDELWEISS detectors for low-mass WIMP searches

    Science.gov (United States)

    Arnaud, Q.; Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Billard, J.; Broniatowski, A.; Camus, P.; Cazes, A.; Chapellier, M.; Charlieux, F.; de Jésus, M.; Dumoulin, L.; Eitel, K.; Foerster, N.; Gascon, J.; Giuliani, A.; Gros, M.; Hehn, L.; Jin, Y.; Juillard, A.; Kleifges, M.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Le-Sueur, H.; Maisonobe, R.; Marnieros, S.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Paul, B.; Poda, D.; Queguiner, E.; Rozov, S.; Sanglard, V.; Scorza, S.; Siebenborn, B.; Vagneron, L.; Weber, M.; Yakushev, E.; EDELWEISS Collaboration

    2018-01-01

    The physics potential of EDELWEISS detectors for the search of low-mass weakly interacting massive particles (WIMPs) is studied. Using a data-driven background model, projected exclusion limits are computed using frequentist and multivariate analysis approaches, namely, profile likelihood and boosted decision tree. Both current and achievable experimental performances are considered. The optimal strategy for detector optimization depends critically on whether the emphasis is put on WIMP masses below or above ˜5 GeV /c2 . The projected sensitivity for the next phase of the EDELWEISS-III experiment at the Modane Underground Laboratory (LSM) for low-mass WIMP search is presented. By 2018 an upper limit on the spin-independent WIMP-nucleon cross section of σSI=7 ×10-42 cm2 is expected for a WIMP mass in the range 2 - 5 GeV /c2 . The requirements for a future hundred-kilogram-scale experiment designed to reach the bounds imposed by the coherent scattering of solar neutrinos are also described. By improving the ionization resolution down to 50 eVe e , we show that such an experiment installed in an even lower background environment (e.g., at SNOLAB) together with an exposure of 1 000 kg .yr , should allow us to observe about 80 B 8 neutrino events after discrimination.

  18. Supersymmetry with Radiatively-Driven Naturalness: Implications for WIMP and Axion Searches

    Directory of Open Access Journals (Sweden)

    Kyu Jung Bae

    2015-05-01

    Full Text Available By insisting on naturalness in both the electroweak and quantum chromodynamics (QCD sectors of the minimal supersymmetric standard model (MSSM, the portrait for dark matter production is seriously modified from the usual weakly interacting massive particle (WIMP miracle picture. In supersymmetry (SUSY models with radiatively-driven naturalness (radiative natural SUSY or radiative natural SUSY (RNS which include a Dine–Fischler–Srednicki–Zhitnitsky (DFSZ-like solution to the strong charge-conjugation-parity (CP and SUSY \\(\\mu\\ problems, dark matter is expected to be an admixture of both axions and higgsino-like WIMPs. The WIMP/axion abundance calculation requires simultaneous solution of a set of coupled Boltzmann equations which describe quasi-stable axinos and saxions. In most of parameter space, axions make up the dominant contribution of dark matter although regions of WIMP dominance also occur. We show the allowed range of Peccei-Quinn (PQ scale \\(f_a\\ and compare to the values expected to be probed by the axion dark matter search experiment (ADMX axion detector in the near future. We also show WIMP detection rates, which are suppressed from usual expectations, because now WIMPs comprise only a fraction of the total dark matter. Nonetheless, ton-scale noble liquid detectors should be able to probe the entirety of RNS parameter space. Indirect WIMP detection rates are less propitious since they are reduced by the square of the depleted WIMP abundance.

  19. First low WIMP mass results in EDELWEISS III experiment

    Energy Technology Data Exchange (ETDEWEB)

    Scorza, Silvia [Karlsruher Institut fuer Technologie, Institut fuer Experimentelle Kernphysik, Postfach 3640, Karlsruhe (Germany); Collaboration: EDELWEISS-Collaboration

    2016-07-01

    The EDELWEISS-III collaboration is operating an experiment for the direct detection of Weakly Interacting Massive Particle (WIMPs) dark matter in the low radioactivity environment of the Modane Underground Laboratory. It consists of twenty-four advanced high purity germanium detectors operating at 18 mK in a dilution refrigerator in order to identify rare nuclear recoils induced by elastic scattering of WIMPs from our Galactic halo. The current EDELWEISS-III program, including improvements of the background, data-acquisition and the configuration is detailed. Sources of background along with the rejection techniques are discussed. Detector performances and a first low WIMP mass analysis of data acquired in a long-term campaign are presented as well.

  20. ZEPLIN-II limits on WIMP-nucelon interactions

    International Nuclear Information System (INIS)

    Alner, G. J.; Bungau, C.; Camanzi, B.; Durkin, T.; Edwards, B.; Lewin, J. D.; Luescher, R.; Preece, R. M.; Smith, N. J. T.; Smith, P. F.; Sumner, T. J.; Thorne, C.; Araujo, H. M.; Bewick, A.; Davidge, D.; Dawson, J.; Howard, A. S.; Jones, W. G.; Joshi, M.; Lebedenko, V. N.

    2009-01-01

    ZEPLIN II is a two-phase xenon detector designed to detect dark matter in the form of Weakly Interacting Massive Particles (WIMPs). Following the first 31-day underground run in Boulby Mine, UK, the collaboration published dark matter limits in January 2007; the first such limits using two-phase xenon technology. We outline the key detector design, performance and results here.

  1. EDICAM (Event Detection Intelligent Camera)

    Energy Technology Data Exchange (ETDEWEB)

    Zoletnik, S. [Wigner RCP RMI, EURATOM Association, Budapest (Hungary); Szabolics, T., E-mail: szabolics.tamas@wigner.mta.hu [Wigner RCP RMI, EURATOM Association, Budapest (Hungary); Kocsis, G.; Szepesi, T.; Dunai, D. [Wigner RCP RMI, EURATOM Association, Budapest (Hungary)

    2013-10-15

    Highlights: ► We present EDICAM's hardware modules. ► We present EDICAM's main design concepts. ► This paper will describe EDICAM firmware architecture. ► Operation principles description. ► Further developments. -- Abstract: A new type of fast framing camera has been developed for fusion applications by the Wigner Research Centre for Physics during the last few years. A new concept was designed for intelligent event driven imaging which is capable of focusing image readout to Regions of Interests (ROIs) where and when predefined events occur. At present these events mean intensity changes and external triggers but in the future more sophisticated methods might also be defined. The camera provides 444 Hz frame rate at full resolution of 1280 × 1024 pixels, but monitoring of smaller ROIs can be done in the 1–116 kHz range even during exposure of the full image. Keeping space limitations and the harsh environment in mind the camera is divided into a small Sensor Module and a processing card interconnected by a fast 10 Gbit optical link. This camera hardware has been used for passive monitoring of the plasma in different devices for example at ASDEX Upgrade and COMPASS with the first version of its firmware. The new firmware and software package is now available and ready for testing the new event processing features. This paper will present the operation principle and features of the Event Detection Intelligent Camera (EDICAM). The device is intended to be the central element in the 10-camera monitoring system of the Wendelstein 7-X stellarator.

  2. Event detection intelligent camera development

    International Nuclear Information System (INIS)

    Szappanos, A.; Kocsis, G.; Molnar, A.; Sarkozi, J.; Zoletnik, S.

    2008-01-01

    A new camera system 'event detection intelligent camera' (EDICAM) is being developed for the video diagnostics of W-7X stellarator, which consists of 10 distinct and standalone measurement channels each holding a camera. Different operation modes will be implemented for continuous and for triggered readout as well. Hardware level trigger signals will be generated from real time image processing algorithms optimized for digital signal processor (DSP) and field programmable gate array (FPGA) architectures. At full resolution a camera sends 12 bit sampled 1280 x 1024 pixels with 444 fps which means 1.43 Terabyte over half an hour. To analyse such a huge amount of data is time consuming and has a high computational complexity. We plan to overcome this problem by EDICAM's preprocessing concepts. EDICAM camera system integrates all the advantages of CMOS sensor chip technology and fast network connections. EDICAM is built up from three different modules with two interfaces. A sensor module (SM) with reduced hardware and functional elements to reach a small and compact size and robust action in harmful environment as well. An image processing and control unit (IPCU) module handles the entire user predefined events and runs image processing algorithms to generate trigger signals. Finally a 10 Gigabit Ethernet compatible image readout card functions as the network interface for the PC. In this contribution all the concepts of EDICAM and the functions of the distinct modules are described

  3. Looking for the WIMP next door

    Science.gov (United States)

    Evans, Jared A.; Gori, Stefania; Shelton, Jessie

    2018-02-01

    We comprehensively study experimental constraints and prospects for a class of minimal hidden sector dark matter (DM) models, highlighting how the cosmological history of these models informs the experimental signals. We study simple `secluded' models, where the DM freezes out into unstable dark mediator states, and consider the minimal cosmic history of this dark sector, where coupling of the dark mediator to the SM was sufficient to keep the two sectors in thermal equilibrium at early times. In the well-motivated case where the dark mediators couple to the Standard Model (SM) via renormalizable interactions, the requirement of thermal equilibrium provides a minimal, UV-insensitive, and predictive cosmology for hidden sector dark matter. We call DM that freezes out of a dark radiation bath in thermal equilibrium with the SM a WIMP next door, and demonstrate that the parameter space for such WIMPs next door is sharply defined, bounded, and in large part potentially accessible. This parameter space, and the corresponding signals, depend on the leading interaction between the SM and the dark mediator; we establish it for both Higgs and vector portal interactions. In particular, there is a cosmological lower bound on the portal coupling strength necessary to thermalize the two sectors in the early universe. We determine this thermalization floor as a function of equilibration temperature for the first time. We demonstrate that direct detection experiments are currently probing this cosmological lower bound in some regions of parameter space, while indirect detection signals and terrestrial searches for the mediator cut further into the viable parameter space. We present regions of interest for both direct detection and dark mediator searches, including motivated parameter space for the direct detection of sub-GeV DM.

  4. Neutrino astronomy and search for WIMPs with MACRO

    CERN Document Server

    Bernardini, P

    2000-01-01

    Upward-going muons, induced primarily by atmospheric neutrinos, are used to search for neutrinos of astrophysical origin. No evidence has been found looking at the event direction and flux limits are obtained on candidate sources. A space-time correlation between gamma ray bursts and upward-going muons has been also investigated. Furthermore the search for a neutrino signal from the Earth and the Sun induced by weakly interacting massive particles (WIMP) has been updated. The number of events from the Sun and from the Earth is compatible with the background from atmospheric neutrinos. Therefore flux limits for different search cones have been estimated. Here we concentrate on neutralinos as WIMP candidates and limits depending on the neutralino mass are given and compared with the prediction of supersymmetric models. (11 refs).

  5. A simple strategy for fall events detection

    KAUST Repository

    Harrou, Fouzi

    2017-01-20

    The paper concerns the detection of fall events based on human silhouette shape variations. The detection of fall events is addressed from the statistical point of view as an anomaly detection problem. Specifically, the paper investigates the multivariate exponentially weighted moving average (MEWMA) control chart to detect fall events. Towards this end, a set of ratios for five partial occupancy areas of the human body for each frame are collected and used as the input data to MEWMA chart. The MEWMA fall detection scheme has been successfully applied to two publicly available fall detection databases, the UR fall detection dataset (URFD) and the fall detection dataset (FDD). The monitoring strategy developed was able to provide early alert mechanisms in the event of fall situations.

  6. Constraints on WIMP masses and interactions

    International Nuclear Information System (INIS)

    Enqvist, K.

    1991-01-01

    It is shown that cosmology, experiments and unitarity considerations limit the mass and coupling g' of a generic, heavy WIMP from the above as well as from the below. There are absolute lower limits of 4x10 -5 g and 6x10 -5 g for the couplings of Diracn and Majorana WIMPs, respectively. In U(1)' models cosmology implies an upper limit of about 1 TeV on the Z' and on the WIMP masses, but only in the absence of Z-Z' mixing. (orig.)

  7. Semblance for microseismic event detection

    Czech Academy of Sciences Publication Activity Database

    Staněk, František; Anikiev, D.; Valenta, Jan; Eisner, Leo

    2015-01-01

    Roč. 201, č. 3 (2015), s. 1362-1369 ISSN 0956-540X R&D Projects: GA ČR GAP210/12/2451 Institutional support: RVO:67985891 Keywords : microseismic event * microseismic monitoring * source mechanisms Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.484, year: 2015

  8. Analyzing direct dark matter detection data with unrejected background events by the AMIDAS website

    International Nuclear Information System (INIS)

    Shan, Chung-Lin

    2012-01-01

    In this talk I have presented the data analysis results of extracting properties of halo WIMPs: the mass and the (ratios between the) spin-independent and spin-dependent couplings/cross sections on nucleons by the AMIDAS website by taking into account possible unrejected background events in the analyzed data sets. Although non-standard astronomical setup has been used to generate pseudodata sets for our analyses, it has been found that, without prior information/assumption about the local density and velocity distribution of halo Dark Matter, these WIMP properties have been reconstructed with ∼ 2% to ∼< 30% deviations from the input values.

  9. NEWSdm: Nuclear Emulsions for WIMP Search with directional measurement

    Directory of Open Access Journals (Sweden)

    Di Crescenzo A.

    2017-01-01

    Full Text Available Direct Dark Matter searches are nowadays one of the most exciting research topics. Several experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs. The measurement of the direction of WIMP-induced nuclear recoils is a challenging strategy to extend dark matter searches beyond the neutrino floor and provide an unambiguous signature of the detection of Galactic dark matter. Current directional experiments are based on the use of gas TPC whose sensitivity is strongly limited by the small achievable detector mass. We present an innovative directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching a position resolution of the order of 10 nm.

  10. NEWSdm: Nuclear Emulsions for WIMP Search with directional measurement

    Science.gov (United States)

    Di Crescenzo, A.

    2017-12-01

    Direct Dark Matter searches are nowadays one of the most exciting research topics. Several experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs). The measurement of the direction of WIMP-induced nuclear recoils is a challenging strategy to extend dark matter searches beyond the neutrino floor and provide an unambiguous signature of the detection of Galactic dark matter. Current directional experiments are based on the use of gas TPC whose sensitivity is strongly limited by the small achievable detector mass. We present an innovative directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching a position resolution of the order of 10 nm.

  11. Projected WIMP Sensitivity of the LUX-ZEPLIN (LZ) Dark Matter Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Akerib, D.S.; et al.

    2018-02-16

    LUX-ZEPLIN (LZ) is a next generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with Weakly Interacting Massive Particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6 tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above $1.6 \\times 10^{-48}$ cm$^{2}$ for a 40 $\\mathrm{GeV}/c^{2}$ mass WIMP. Additionally, a $5\\sigma$ discovery potential is projected reaching cross sections below the existing and projected exclusion limits of similar experiments that are currently operating. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of $2.7 \\times 10^{-43}$ cm$^{2}$ ($8.1 \\times 10^{-42}$ cm$^{2}$) for a 40 $\\mathrm{GeV}/c^{2}$ mass WIMP is expected. With construction well underway, LZ is on track for underground installation at SURF in 2019 and will start collecting data in 2020.

  12. Joint Attributes and Event Analysis for Multimedia Event Detection.

    Science.gov (United States)

    Ma, Zhigang; Chang, Xiaojun; Xu, Zhongwen; Sebe, Nicu; Hauptmann, Alexander G

    2017-06-15

    Semantic attributes have been increasingly used the past few years for multimedia event detection (MED) with promising results. The motivation is that multimedia events generally consist of lower level components such as objects, scenes, and actions. By characterizing multimedia event videos with semantic attributes, one could exploit more informative cues for improved detection results. Much existing work obtains semantic attributes from images, which may be suboptimal for video analysis since these image-inferred attributes do not carry dynamic information that is essential for videos. To address this issue, we propose to learn semantic attributes from external videos using their semantic labels. We name them video attributes in this paper. In contrast with multimedia event videos, these external videos depict lower level contents such as objects, scenes, and actions. To harness video attributes, we propose an algorithm established on a correlation vector that correlates them to a target event. Consequently, we could incorporate video attributes latently as extra information into the event detector learnt from multimedia event videos in a joint framework. To validate our method, we perform experiments on the real-world large-scale TRECVID MED 2013 and 2014 data sets and compare our method with several state-of-the-art algorithms. The experiments show that our method is advantageous for MED.

  13. Detection of neutral current events

    International Nuclear Information System (INIS)

    Innocenti, P.G.

    1979-01-01

    The topics investigated in the course of the study can be broadly divided into three classes: (i) Inclusive measurements of the scattered electron for the determination of structure functions, scaling violations, deltaL/deltaT and weak interaction effects. (ii) Exclusive measurements of the current jet (momentum, energy, particle composition) for the study of fragmentation functions, for search of new particles, new quarks and QCD effects in the jet. (iii) Search for heavy leptons by detection and identification of their decay products. (orig.)

  14. Generalized Detectability for Discrete Event Systems

    Science.gov (United States)

    Shu, Shaolong; Lin, Feng

    2011-01-01

    In our previous work, we investigated detectability of discrete event systems, which is defined as the ability to determine the current and subsequent states of a system based on observation. For different applications, we defined four types of detectabilities: (weak) detectability, strong detectability, (weak) periodic detectability, and strong periodic detectability. In this paper, we extend our results in three aspects. (1) We extend detectability from deterministic systems to nondeterministic systems. Such a generalization is necessary because there are many systems that need to be modeled as nondeterministic discrete event systems. (2) We develop polynomial algorithms to check strong detectability. The previous algorithms are based on observer whose construction is of exponential complexity, while the new algorithms are based on a new automaton called detector. (3) We extend detectability to D-detectability. While detectability requires determining the exact state of a system, D-detectability relaxes this requirement by asking only to distinguish certain pairs of states. With these extensions, the theory on detectability of discrete event systems becomes more applicable in solving many practical problems. PMID:21691432

  15. Cartan invariants and event horizon detection

    Science.gov (United States)

    Brooks, D.; Chavy-Waddy, P. C.; Coley, A. A.; Forget, A.; Gregoris, D.; MacCallum, M. A. H.; McNutt, D. D.

    2018-04-01

    We show that it is possible to locate the event horizon of a black hole (in arbitrary dimensions) by the zeros of certain Cartan invariants. This approach accounts for the recent results on the detection of stationary horizons using scalar polynomial curvature invariants, and improves upon them since the proposed method is computationally less expensive. As an application, we produce Cartan invariants that locate the event horizons for various exact four-dimensional and five-dimensional stationary, asymptotically flat (or (anti) de Sitter), black hole solutions and compare the Cartan invariants with the corresponding scalar curvature invariants that detect the event horizon.

  16. The waning of the WIMP? A review of models, searches, and constraints

    Science.gov (United States)

    Arcadi, Giorgio; Dutra, Maíra; Ghosh, Pradipta; Lindner, Manfred; Mambrini, Yann; Pierre, Mathias; Profumo, Stefano; Queiroz, Farinaldo S.

    2018-03-01

    Weakly Interacting Massive Particles (WIMPs) are among the best-motivated dark matter candidates. No conclusive signal, despite an extensive search program that combines, often in a complementary way, direct, indirect, and collider probes, has been detected so far. This situation might change in near future due to the advent of one/multi-TON Direct Detection experiments. We thus, find it timely to provide a review of the WIMP paradigm with focus on a few models which can be probed at best by these facilities. Collider and Indirect Detection, nevertheless, will not be neglected when they represent a complementary probe.

  17. Joint Rome Workshop "Challenges in the Dark Sector: Alternatives to the WIMP paradigm”

    CERN Document Server

    2015-01-01

    Identifying what Dark Matter (DM) is, as well as its nature and properties, remains a major challenge for both theoretical and experimental astroparticle physics communities. In the past decades, WIMP DM has been the most hunted candidate, with the result that nowadays WIMPS are cornered by large amounts of experimental data from Direct Detection, Indirect Detection, and Collider Experiments. If no WIMP signal is detected in the next few years, the possibility that this very appealing theoretical idea is not what Nature has chosen will become even more compelling and will boost theoretical studies and experimental searches for non-WIMP alternatives for DM. The aim of this 3-day meeting is to convene experts on alternatives to the WIMP paradigm to stimulate informal discussions on different possibilities (dark photons, axion-like particles, Majorons, self-interacting dark sectors, just to mention a few). We plan to have only three or four talks each day, and plenty of time to discuss implications of these DM s...

  18. Signal modulation in cold-dark-matter detection

    International Nuclear Information System (INIS)

    Freese, K.; Frieman, J.; Gould, A.

    1988-01-01

    If weakly interacting massive particles (WIMP's) are the dark matter in the galactic halo, they may be detected in low-background ionization detectors now operating or with low-temperature devices under development. In detecting WIMP's of low mass or WIMP's with spin-dependent nuclear interactions (e.g., photinos), a principal technical difficulty appears to be achieving very low thresholds (approx. < keV) in large (∼ kg) detectors with low background noise. We present an analytic treatment of WIMP detection and show that the seasonal modulation of the signal can be used to detect WIMP's even at low-signal-to-background levels and thus without the necessity of going to very-low-energy thresholds. As a result, the prospects for detecting a variety of cold-dark-matter candidates may be closer at hand than previously thought. We discuss in detail the detector characteristics required for a number of WIMP candidates, and carefully work out expected event rates for several present and proposed detectors

  19. Semantic Context Detection Using Audio Event Fusion

    Directory of Open Access Journals (Sweden)

    Cheng Wen-Huang

    2006-01-01

    Full Text Available Semantic-level content analysis is a crucial issue in achieving efficient content retrieval and management. We propose a hierarchical approach that models audio events over a time series in order to accomplish semantic context detection. Two levels of modeling, audio event and semantic context modeling, are devised to bridge the gap between physical audio features and semantic concepts. In this work, hidden Markov models (HMMs are used to model four representative audio events, that is, gunshot, explosion, engine, and car braking, in action movies. At the semantic context level, generative (ergodic hidden Markov model and discriminative (support vector machine (SVM approaches are investigated to fuse the characteristics and correlations among audio events, which provide cues for detecting gunplay and car-chasing scenes. The experimental results demonstrate the effectiveness of the proposed approaches and provide a preliminary framework for information mining by using audio characteristics.

  20. Metrics for Polyphonic Sound Event Detection

    Directory of Open Access Journals (Sweden)

    Annamaria Mesaros

    2016-05-01

    Full Text Available This paper presents and discusses various metrics proposed for evaluation of polyphonic sound event detection systems used in realistic situations where there are typically multiple sound sources active simultaneously. The system output in this case contains overlapping events, marked as multiple sounds detected as being active at the same time. The polyphonic system output requires a suitable procedure for evaluation against a reference. Metrics from neighboring fields such as speech recognition and speaker diarization can be used, but they need to be partially redefined to deal with the overlapping events. We present a review of the most common metrics in the field and the way they are adapted and interpreted in the polyphonic case. We discuss segment-based and event-based definitions of each metric and explain the consequences of instance-based and class-based averaging using a case study. In parallel, we provide a toolbox containing implementations of presented metrics.

  1. Detection of goal events in soccer videos

    Science.gov (United States)

    Kim, Hyoung-Gook; Roeber, Steffen; Samour, Amjad; Sikora, Thomas

    2005-01-01

    In this paper, we present an automatic extraction of goal events in soccer videos by using audio track features alone without relying on expensive-to-compute video track features. The extracted goal events can be used for high-level indexing and selective browsing of soccer videos. The detection of soccer video highlights using audio contents comprises three steps: 1) extraction of audio features from a video sequence, 2) event candidate detection of highlight events based on the information provided by the feature extraction Methods and the Hidden Markov Model (HMM), 3) goal event selection to finally determine the video intervals to be included in the summary. For this purpose we compared the performance of the well known Mel-scale Frequency Cepstral Coefficients (MFCC) feature extraction method vs. MPEG-7 Audio Spectrum Projection feature (ASP) extraction method based on three different decomposition methods namely Principal Component Analysis( PCA), Independent Component Analysis (ICA) and Non-Negative Matrix Factorization (NMF). To evaluate our system we collected five soccer game videos from various sources. In total we have seven hours of soccer games consisting of eight gigabytes of data. One of five soccer games is used as the training data (e.g., announcers' excited speech, audience ambient speech noise, audience clapping, environmental sounds). Our goal event detection results are encouraging.

  2. A simple strategy for fall events detection

    KAUST Repository

    Harrou, Fouzi; Zerrouki, Nabil; Sun, Ying; Houacine, Amrane

    2017-01-01

    the multivariate exponentially weighted moving average (MEWMA) control chart to detect fall events. Towards this end, a set of ratios for five partial occupancy areas of the human body for each frame are collected and used as the input data to MEWMA chart

  3. Adaptive prediction applied to seismic event detection

    International Nuclear Information System (INIS)

    Clark, G.A.; Rodgers, P.W.

    1981-01-01

    Adaptive prediction was applied to the problem of detecting small seismic events in microseismic background noise. The Widrow-Hoff LMS adaptive filter used in a prediction configuration is compared with two standard seismic filters as an onset indicator. Examples demonstrate the technique's usefulness with both synthetic and actual seismic data

  4. Adaptive prediction applied to seismic event detection

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.A.; Rodgers, P.W.

    1981-09-01

    Adaptive prediction was applied to the problem of detecting small seismic events in microseismic background noise. The Widrow-Hoff LMS adaptive filter used in a prediction configuration is compared with two standard seismic filters as an onset indicator. Examples demonstrate the technique's usefulness with both synthetic and actual seismic data.

  5. Boffins go underground searching for Wimps

    CERN Multimedia

    2003-01-01

    In a bid to identify the prime suspect for Dark Matter known as Weakly Interacting Massive Particles, or Wimps, British scientists have installed detectors 1100m down a salt mine at Boulby on the North Yorkshire moors (1/2 page).

  6. Power corrections to the universal heavy WIMP-nucleon cross section

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chien-Yi; Hill, Richard J.; Solon, Mikhail P.; Wijangco, Alexander M.

    2018-06-01

    WIMP-nucleon scattering is analyzed at order $1/M$ in Heavy WIMP Effective Theory. The $1/M$ power corrections, where $M\\gg m_W$ is the WIMP mass, distinguish between different underlying UV models with the same universal limit and their impact on direct detection rates can be enhanced relative to naive expectations due to generic amplitude-level cancellations at leading order. The necessary one- and two-loop matching calculations onto the low-energy effective theory for WIMP interactions with Standard Model quarks and gluons are performed for the case of an electroweak SU(2) triplet WIMP, considering both the cases of elementary fermions and composite scalars. The low-velocity WIMP-nucleon scattering cross section is evaluated and compared with current experimental limits and projected future sensitivities. Our results provide the most robust prediction for electroweak triplet Majorana fermion dark matter direct detection rates; for this case, a cancellation between two sources of power corrections yields a small total $1/M$ correction, and a total cross section close to the universal limit for $M \\gtrsim {\\rm few} \\times 100\\,{\\rm GeV}$. For the SU(2) composite scalar, the $1/M$ corrections introduce dependence on underlying strong dynamics. Using a leading chiral logarithm evaluation, the total $1/M$ correction has a larger magnitude and uncertainty than in the fermionic case, with a sign that further suppresses the total cross section. These examples provide definite targets for future direct detection experiments and motivate large scale detectors capable of probing to the neutrino floor in the TeV mass regime.

  7. Power corrections to the universal heavy WIMP-nucleon cross section

    Science.gov (United States)

    Chen, Chien-Yi; Hill, Richard J.; Solon, Mikhail P.; Wijangco, Alexander M.

    2018-06-01

    WIMP-nucleon scattering is analyzed at order 1 / M in Heavy WIMP Effective Theory. The 1 / M power corrections, where M ≫mW is the WIMP mass, distinguish between different underlying UV models with the same universal limit and their impact on direct detection rates can be enhanced relative to naive expectations due to generic amplitude-level cancellations at leading order. The necessary one- and two-loop matching calculations onto the low-energy effective theory for WIMP interactions with Standard Model quarks and gluons are performed for the case of an electroweak SU(2) triplet WIMP, considering both the cases of elementary fermions and composite scalars. The low-velocity WIMP-nucleon scattering cross section is evaluated and compared with current experimental limits and projected future sensitivities. Our results provide the most robust prediction for electroweak triplet Majorana fermion dark matter direct detection rates; for this case, a cancellation between two sources of power corrections yields a small total 1 / M correction, and a total cross section close to the universal limit for M ≳ few × 100GeV. For the SU(2) composite scalar, the 1 / M corrections introduce dependence on underlying strong dynamics. Using a leading chiral logarithm evaluation, the total 1 / M correction has a larger magnitude and uncertainty than in the fermionic case, with a sign that further suppresses the total cross section. These examples provide definite targets for future direct detection experiments and motivate large scale detectors capable of probing to the neutrino floor in the TeV mass regime.

  8. Exclusion limits on the WIMP-nucleon cross section from the Cryogenic Dark Matter Search

    International Nuclear Information System (INIS)

    Abrams, D.; Baudis, L.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Chang, C.L.; Clarke, R.M.; Saab, T.; Akerib, D.S.; Bolozdynya, A.; Driscoll, D.; Kamat, S.; Perera, T.A.; Schnee, R.W.; Wang, G.; Armel-Funkhouser, M.S.; Golwala, S.R.; Hellmig, J.; Mandic, V.; Meunier, P.

    2002-01-01

    The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to ∼10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons in all ways tested. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross section exclude unexplored parameter space for WIMPs with masses between 10-70 GeV/c 2 . These limits border, but do not exclude, parameter space allowed by supersymmetry models and accelerator constraints. Results are compatible with some regions reported as allowed at 3σ by the annual-modulation measurement of the DAMA Collaboration. However, under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the DAMA most likely value at >99.9% confidence level (C.L.), and are incompatible with the model-independent annual-modulation signal of DAMA at 99.99% C.L. in the asymptotic limit

  9. Abnormal Event Detection Using Local Sparse Representation

    DEFF Research Database (Denmark)

    Ren, Huamin; Moeslund, Thomas B.

    2014-01-01

    We propose to detect abnormal events via a sparse subspace clustering algorithm. Unlike most existing approaches, which search for optimized normal bases and detect abnormality based on least square error or reconstruction error from the learned normal patterns, we propose an abnormality measurem...... is found that satisfies: the distance between its local space and the normal space is large. We evaluate our method on two public benchmark datasets: UCSD and Subway Entrance datasets. The comparison to the state-of-the-art methods validate our method's effectiveness....

  10. First CNGS events detected by LVD

    International Nuclear Information System (INIS)

    Agafonova, N.Yu.; Boyarkin, V.V.; Kuznetsov, V.V.; Kuznetsov, V.A.; Malguin, A.S.; Ryasny, V.G.; Ryazhskaya, O.G.; Yakushev, V.F.; Zatsepin, G.T.; Aglietta, M.; Bonardi, A.; Fulgione, W.; Galeotti, P.; Porta, A.; Saavedra, O.; Vigorito, C.; Antonioli, P.; Bari, G.; Giusti, P.; Menghetti, H.; Persiani, R.; Pesci, A.; Sartorelli, G.; Selvi, M.; Zichichi, A.; Bruno, G.; Ghia, P.L.; Garbini, M.; Kemp, E.; Pless, I.A.; Votano, L.

    2007-01-01

    The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band ν μ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the ν τ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of 7.6 x 10 17 protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Monte Carlo simulations. (orig.)

  11. First CNGS events detected by LVD

    International Nuclear Information System (INIS)

    Selvi, M.

    2007-01-01

    The Cern Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band ν μ beam at Cern and send it towards the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the ν τ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of 7.6 10 17 protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations

  12. A precision search for WIMPs with charged cosmic rays

    Science.gov (United States)

    Reinert, Annika; Winkler, Martin Wolfgang

    2018-01-01

    AMS-02 has reached the sensitivity to probe canonical thermal WIMPs by their annihilation into antiprotons. Due to the high precision of the data, uncertainties in the astrophysical background have become the most limiting factor for indirect dark matter detection. In this work we systematically quantify and—where possible—reduce uncertainties in the antiproton background. We constrain the propagation of charged cosmic rays through the combination of antiproton, B/C and positron data. Cross section uncertainties are determined from a wide collection of accelerator data and are—for the first time ever—fully taken into account. This allows us to robustly constrain even subdominant dark matter signals through their spectral properties. For a standard NFW dark matter profile we are able to exclude thermal WIMPs with masses up to 570 GeV which annihilate into bottom quarks. While we confirm a reported excess compatible with dark matter of mass around 80 GeV, its local (global) significance only reaches 2.2 σ (1.1 σ) in our analysis.

  13. LAN attack detection using Discrete Event Systems.

    Science.gov (United States)

    Hubballi, Neminath; Biswas, Santosh; Roopa, S; Ratti, Ritesh; Nandi, Sukumar

    2011-01-01

    Address Resolution Protocol (ARP) is used for determining the link layer or Medium Access Control (MAC) address of a network host, given its Internet Layer (IP) or Network Layer address. ARP is a stateless protocol and any IP-MAC pairing sent by a host is accepted without verification. This weakness in the ARP may be exploited by malicious hosts in a Local Area Network (LAN) by spoofing IP-MAC pairs. Several schemes have been proposed in the literature to circumvent these attacks; however, these techniques either make IP-MAC pairing static, modify the existing ARP, patch operating systems of all the hosts etc. In this paper we propose a Discrete Event System (DES) approach for Intrusion Detection System (IDS) for LAN specific attacks which do not require any extra constraint like static IP-MAC, changing the ARP etc. A DES model is built for the LAN under both a normal and compromised (i.e., spoofed request/response) situation based on the sequences of ARP related packets. Sequences of ARP events in normal and spoofed scenarios are similar thereby rendering the same DES models for both the cases. To create different ARP events under normal and spoofed conditions the proposed technique uses active ARP probing. However, this probing adds extra ARP traffic in the LAN. Following that a DES detector is built to determine from observed ARP related events, whether the LAN is operating under a normal or compromised situation. The scheme also minimizes extra ARP traffic by probing the source IP-MAC pair of only those ARP packets which are yet to be determined as genuine/spoofed by the detector. Also, spoofed IP-MAC pairs determined by the detector are stored in tables to detect other LAN attacks triggered by spoofing namely, man-in-the-middle (MiTM), denial of service etc. The scheme is successfully validated in a test bed. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Calculated WIMP signals at the ANDES laboratory: comparison with northern and southern located dark matter detectors

    Science.gov (United States)

    Civitarese, O.; Fushimi, K. J.; Mosquera, M. E.

    2016-12-01

    Weakly interacting massive particles (WIMPs) are possible components of the Universe’s dark matter (DM). The detection of WIMPs is signaled by the recoil of the atomic nuclei which form a detector. CoGeNT at the Soudan Underground Laboratory (SUL) and DAMA at the Laboratori Nazionali del Gran Sasso (LNGS) have reported data on annual modulation of signals attributed to WIMPs. Both experiments are located in laboratories in the Northern Hemisphere. DM detectors are planned to operate (or already operate) in laboratories in the Southern Hemisphere, including SABRE at Stawell Underground Physics Laboratory (SUPL) in Australia, and DM-ICE in Antarctica. In this work we have analyzed the dependence of diurnal and annual modulation of signals, pertaining to the detection of WIMP, on the coordinates of the laboratory, for experiments which may be performed in the planned new Agua Negra Deep Experimental Site (ANDES) underground facility, to be built in San Juan, Argentina. We made predictions for NaI and Ge-type detectors placed in ANDES, to compare with DAMA, CoGeNT, SABRE and DM-ICE arrays, and found that the diurnal modulation of the signals, at the ANDES site, is amplified at its maximum value, both for NaI (Ge)-type detectors, while the annual modulation remains unaffected by the change in coordinates from north to south.

  15. Calculated WIMP signals at the ANDES laboratory: comparison with northern and southern located dark matter detectors

    International Nuclear Information System (INIS)

    Civitarese, O; Mosquera, M E; Fushimi, K J

    2016-01-01

    Weakly interacting massive particles (WIMPs) are possible components of the Universe’s dark matter (DM). The detection of WIMPs is signaled by the recoil of the atomic nuclei which form a detector. CoGeNT at the Soudan Underground Laboratory (SUL) and DAMA at the Laboratori Nazionali del Gran Sasso (LNGS) have reported data on annual modulation of signals attributed to WIMPs. Both experiments are located in laboratories in the Northern Hemisphere. DM detectors are planned to operate (or already operate) in laboratories in the Southern Hemisphere, including SABRE at Stawell Underground Physics Laboratory (SUPL) in Australia, and DM-ICE in Antarctica. In this work we have analyzed the dependence of diurnal and annual modulation of signals, pertaining to the detection of WIMP, on the coordinates of the laboratory, for experiments which may be performed in the planned new Agua Negra Deep Experimental Site (ANDES) underground facility, to be built in San Juan, Argentina. We made predictions for NaI and Ge-type detectors placed in ANDES, to compare with DAMA, CoGeNT, SABRE and DM-ICE arrays, and found that the diurnal modulation of the signals, at the ANDES site, is amplified at its maximum value, both for NaI (Ge)-type detectors, while the annual modulation remains unaffected by the change in coordinates from north to south. (paper)

  16. Multilingual event extraction for epidemic detection.

    Science.gov (United States)

    Lejeune, Gaël; Brixtel, Romain; Doucet, Antoine; Lucas, Nadine

    2015-10-01

    This paper presents a multilingual news surveillance system applied to tele-epidemiology. It has been shown that multilingual approaches improve timeliness in detection of epidemic events across the globe, eliminating the wait for local news to be translated into major languages. We present here a system to extract epidemic events in potentially any language, provided a Wikipedia seed for common disease names exists. The Daniel system presented herein relies on properties that are common to news writing (the journalistic genre), the most useful being repetition and saliency. Wikipedia is used to screen common disease names to be matched with repeated characters strings. Language variations, such as declensions, are handled by processing text at the character-level, rather than at the word level. This additionally makes it possible to handle various writing systems in a similar fashion. As no multilingual ground truth existed to evaluate the Daniel system, we built a multilingual corpus from the Web, and collected annotations from native speakers of Chinese, English, Greek, Polish and Russian, with no connection or interest in the Daniel system. This data set is available online freely, and can be used for the evaluation of other event extraction systems. Experiments for 5 languages out of 17 tested are detailed in this paper: Chinese, English, Greek, Polish and Russian. The Daniel system achieves an average F-measure of 82% in these 5 languages. It reaches 87% on BEcorpus, the state-of-the-art corpus in English, slightly below top-performing systems, which are tailored with numerous language-specific resources. The consistent performance of Daniel on multiple languages is an important contribution to the reactivity and the coverage of epidemiological event detection systems. Most event extraction systems rely on extensive resources that are language-specific. While their sophistication induces excellent results (over 90% precision and recall), it restricts their

  17. First 5 tower WIMP-search results from the Cryogenic Dark Matter Search with improved understanding of neutron backgrounds and benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Hennings-Yeomans, Raul [Case Western Reserve Univ., Cleveland, OH (United States)

    2009-02-01

    Non-baryonic dark matter makes one quarter of the energy density of the Universe and is concentrated in the halos of galaxies, including the Milky Way. The Weakly Interacting Massive Particle (WIMP) is a dark matter candidate with a scattering cross section with an atomic nucleus of the order of the weak interaction and a mass comparable to that of an atomic nucleus. The Cryogenic Dark Matter Search (CDMS-II) experiment, using Ge and Si cryogenic particle detectors at the Soudan Underground Laboratory, aims to directly detect nuclear recoils from WIMP interactions. This thesis presents the first 5 tower WIMP-search results from CDMS-II, an estimate of the cosmogenic neutron backgrounds expected at the Soudan Underground Laboratory, and a proposal for a new measurement of high-energy neutrons underground to benchmark the Monte Carlo simulations. Based on the non-observation of WIMPs and using standard assumptions about the galactic halo [68], the 90% C.L. upper limit of the spin-independent WIMPnucleon cross section for the first 5 tower run is 6.6 × 10-44cm2 for a 60 GeV/c2 WIMP mass. A combined limit using all the data taken at Soudan results in an upper limit of 4.6×10-44cm2 at 90% C.L.for a 60 GeV/c2 WIMP mass. This new limit corresponds to a factor of ~3 improvement over any previous CDMS-II limit and a factor of ~2 above 60 GeV/c 2 better than any other WIMP search to date. This thesis presents an estimation, based on Monte Carlo simulations, of the nuclear recoils produced by cosmic-ray muons and their secondaries (at the Soudan site) for a 5 tower Ge and Si configuration as well as for a 7 supertower array. The results of the Monte Carlo are that CDMS-II should expect 0.06 ± 0.02+0.18 -0.02 /kgyear unvetoed single nuclear recoils in Ge for the 5 tower configuration, and 0.05 ± 0.01+0.15 -0.02 /kg-year for the 7 supertower configuration. The systematic error is based on the available

  18. Detector Simulation and WIMP Search Analysis for the Cryogenic Dark Matter Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Kevin [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2013-06-01

    Astrophysical and cosmological measurements on the scales of galaxies, galaxy clusters, and the universe indicate that 85% of the matter in the universe is composed of dark matter, made up of non-baryonic particles that interact with cross-sections on the weak scale or lower. Hypothetical Weakly Interacting Massive Particles, or WIMPs, represent a potential solution to the dark matter problem, and naturally arise in certain Standard Model extensions. The Cryogenic Dark Matter Search (CDMS) collaboration aims to detect the scattering of WIMP particles from nuclei in terrestrial detectors. Germanium and silicon particle detectors are deployed in the Soudan Underground Laboratory in Minnesota. These detectors are instrumented with phonon and ionization sensors, which allows for discrimination against electromagnetic backgrounds, which strike the detector at rates orders of magnitude higher than the expected WIMP signal. This dissertation presents the development of numerical models of the physics of the CDMS detectors, implemented in a computational package collectively known as the CDMS Detector Monte Carlo (DMC). After substantial validation of the models against data, the DMC is used to investigate potential backgrounds to the next iteration of the CDMS experiment, known as SuperCDMS. Finally, an investigation of using the DMC in a reverse Monte Carlo analysis of WIMP search data is presented.

  19. WIMP search and a Cherenkov detector prototype for ILC polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Christoph

    2011-10-15

    The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e{sup +}e{sup -} {yields} {chi}{chi}{gamma}, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb{sup -1}, the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of {delta} P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the

  20. WIMP search and a Cherenkov detector prototype for ILC polarimetry

    International Nuclear Information System (INIS)

    Bartels, Christoph

    2011-10-01

    The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e + e - → χχγ, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb -1 , the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of δ P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the required precision. At ILC, these

  1. Neutrinos from WIMP annihilations obtained using a full three-flavor Monte Carlo approach

    International Nuclear Information System (INIS)

    Blennow, Mattias; Ohlsson, Tommy; Edsjö, Joakim

    2008-01-01

    Weakly interacting massive particles (WIMPs) are one of the main candidates for making up the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effects from neutrino interactions on the way through the Sun (absorption, energy loss, and regeneration from tau decays). In addition, we study the effects of non-zero values of the mixing angle θ 13 as well as the normal and inverted neutrino mass hierarchies. Our study is performed in an event-based setting which makes these results very useful both for theoretical analyses and for building a neutrino telescope Monte Carlo code. All our results for the neutrino yields, as well as our Monte Carlo code, are publicly available. We find that the yield of muon-type neutrinos from WIMP annihilations in the Sun is enhanced or suppressed, depending on the dominant WIMP annihilation channel. This effect is due to an effective flavor mixing caused by neutrino oscillations. For WIMP annihilations inside the Earth, the distance from source to detector is too small to allow for any significant amount of oscillations at the neutrino energies relevant for neutrino telescopes

  2. A Search for WIMP Dark Matter Using the First Five-Tower Run of the Cryogenic Dark Matter Search

    Energy Technology Data Exchange (ETDEWEB)

    Filippini, Jeffrey Peter [UC, Berkeley

    2008-01-01

    In recent decades astronomers and physicists have accumulated a vast array of evidence that the bulk of the universe's matter is in some non-baryonic form that remains undetected by electromagnetic means. This \\dark matter" resides in diuse halos surrounding galaxies and other cosmic structures. Particle theorists have proposed a wide array of candidates for its nature. One particularly promising class of candidates are Weakly Interacting Massive Particles (WIMPs): quanta with masses of order 100 GeV/c2 and interactions characteristic of the weak nuclear force. The Cryogenic Dark Matter Search (CDMS) experiment seeks to directly detect the rare elastic interactions of galactic WIMPs with terrestrial nuclei. To this end, CDMS operates an array of crystalline Ge and Si particle detectors in Soudan Underground Laboratory in northern Minnesota. These crystals are operated at millikelvin temperatures and instrumented to measure the ionization and athermal phonons generated by each particle interaction. This combination provides a powerful two-fold discrimination against the interactions of particles generated by radioactive decay and cosmogenic showers. This dissertation describes the commissioning, analysis, and results of the rst WIMP-search data runs of the CDMS experiment with its full complement of 5 \\Towers" of detectors. These data represent a substantial increase in target mass and exposure over previous CDMS results. The results of this work place the most stringent limits yet set upon the WIMP-nucleon spin-independent cross section for WIMP masses above 44 GeV/c2 , as well as setting competitive limits on spin-dependent WIMP-nucleon interactions. This work also outlines the larger context of this and other probes of the WIMP theory of dark matter, as well as some current development eorts toward a larger cryogenic experiment.

  3. Beyond WIMPs: the Quark (Anti Nugget Dark Matter

    Directory of Open Access Journals (Sweden)

    Zhitnitsky Ariel

    2017-01-01

    Full Text Available We review a testable dark matter (DM model outside of the standard WIMP paradigm. The model is unique in a sense that the observed ratio Ωdark ≃ Ωvisible for visible and dark matter densities finds its natural explanation as a result of their common QCD origin when both types of matter (DM and visible are formed during the QCD phase transition and both are proportional to single dimensional parameter of the system, Λqcd. We argue that the charge separation effect also inevitably occurs during the same QCD phase transition in the presence of the CP odd axion field a(x. It leads to preferential formation of one species of nuggets on the scales of the visible Universe where the axion field a(x is coherent. A natural outcome of this preferential evolution is that only one type of the visible baryons (not anti- baryons remain in the system after the nuggets complete their formation. Unlike conventional WIMP dark matter candidates, the nuggets and anti-nuggets are strongly interacting but macroscopically large objects. The rare events of annihilation of the anti-nuggets with visible matter lead to a number of observable effects. We argue that the relative intensities for a number of measured excesses of emission from the centre of galaxy (covering more than 11 orders of magnitude are determined by standard and well established physics. At the same time the absolute intensity of emission is determined by a single new fundamental parameter of the theory, the axion mass, 10−6eV ≲ ma ≲ 10−3eV. Finally, we comment on implications of these studies for the axion search experiments, including microwave cavity and the Orpheus experiments.

  4. WIMP dark matter candidates and searches—current status and future prospects

    Science.gov (United States)

    Roszkowski, Leszek; Sessolo, Enrico Maria; Trojanowski, Sebastian

    2018-06-01

    We review several current aspects of dark matter theory and experiment. We overview the present experimental status, which includes current bounds and recent claims and hints of a possible signal in a wide range of experiments: direct detection in underground laboratories, gamma-ray, cosmic ray, x-ray, neutrino telescopes, and the LHC. We briefly review several possible particle candidates for a weakly interactive massive particle (WIMP) and dark matter that have recently been considered in the literature. We pay particular attention to the lightest neutralino of supersymmetry as it remains the best motivated candidate for dark matter and also shows excellent detection prospects. Finally we briefly review some alternative scenarios that can considerably alter properties and prospects for the detection of dark matter obtained within the standard thermal WIMP paradigm.

  5. WIMP dark matter candidates and searches-current status and future prospects.

    Science.gov (United States)

    Roszkowski, Leszek; Sessolo, Enrico Maria; Trojanowski, Sebastian

    2018-06-01

    We review several current aspects of dark matter theory and experiment. We overview the present experimental status, which includes current bounds and recent claims and hints of a possible signal in a wide range of experiments: direct detection in underground laboratories, gamma-ray, cosmic ray, x-ray, neutrino telescopes, and the LHC. We briefly review several possible particle candidates for a weakly interactive massive particle (WIMP) and dark matter that have recently been considered in the literature. We pay particular attention to the lightest neutralino of supersymmetry as it remains the best motivated candidate for dark matter and also shows excellent detection prospects. Finally we briefly review some alternative scenarios that can considerably alter properties and prospects for the detection of dark matter obtained within the standard thermal WIMP paradigm.

  6. Markov chain Monte Carlo analysis to constrain dark matter properties with directional detection

    International Nuclear Information System (INIS)

    Billard, J.; Mayet, F.; Santos, D.

    2011-01-01

    Directional detection is a promising dark matter search strategy. Indeed, weakly interacting massive particle (WIMP)-induced recoils would present a direction dependence toward the Cygnus constellation, while background-induced recoils exhibit an isotropic distribution in the Galactic rest frame. Taking advantage of these characteristic features, and even in the presence of a sizeable background, it has recently been shown that data from forthcoming directional detectors could lead either to a competitive exclusion or to a conclusive discovery, depending on the value of the WIMP-nucleon cross section. However, it is possible to further exploit these upcoming data by using the strong dependence of the WIMP signal with: the WIMP mass and the local WIMP velocity distribution. Using a Markov chain Monte Carlo analysis of recoil events, we show for the first time the possibility to constrain the unknown WIMP parameters, both from particle physics (mass and cross section) and Galactic halo (velocity dispersion along the three axis), leading to an identification of non-baryonic dark matter.

  7. Results and status of the Edelweiss Wimp search experiment

    International Nuclear Information System (INIS)

    Benoit, A.; Berge, L.; Blumer, J.; Broniatowski, A.; Censier, B.; Chabert, L.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; Jesus, M. de; Drain, D.; Di Stefano, P.; Dumoulin, L.; Eitel, K.; Fesquet, M.; Firucci, S.; Gascon, J.; Gerbier, G.; Gerlic, E.; Goldbach, C.; Goyot, M.; Gros, M.; Habermahl, F.; Horn, M.; Hadjout, J.P.; Herve, S.; Juillard, A.; Kikuchi, C.; Lesquen, A. de; Luca, M.; Mallet, J.; Marnieros, S.; Martineau, O.; Mosca, L.; Navick, X.F.; Nollez, G.; Pari, P.; Riccio, C.; Sanglard, V.; Stern, M.; Vagneron, L.; Villard, V.

    2005-01-01

    In the Edelweiss experiment, nuclear recoils induced by elastic collisions with WIMPs (weakly interacting massive particle) from the galactic halo are identified in low-temperature Ge detectors where the ratio of the heat and ionization signals provide an event-by-event discrimination of nuclear recoils from the dominant background coming from γ-rays interactions. The Edelweiss experiment is located in the Modane underground facility in order to cut the muon flux drastically. We present here the results obtained during the first part of the experiment named Edelweiss-I that ended in the beginning of 2004. Since october 2002, 3 optimized 320 grams detectors have been simultaneously operated at a regulated temperature of 0.017 K and about 50 kg*day were added to the previous published data. These data are still under analysis but preliminary results concerning the upper limit at 90% CL (confidence level) confirm the limit already published in 2002. The first run of Edelweiss-II is due to begin during summer 2005, we are expecting to gain 2 orders of magnitude in terms of detector sensitivity and reach 0.002 events/day*kg. (A.C.)

  8. Large-scale nuclear structure calculations for spin-dependent WIMP scattering with chiral effective field theory currents

    OpenAIRE

    Klos, P.; Menéndez, J.; Gazit, D.; Schwenk, A.

    2013-01-01

    We perform state-of-the-art large-scale shell-model calculations of the structure factors for elastic spin-dependent WIMP scattering off 129,131Xe, 127I, 73Ge, 19F, 23Na, 27Al, and 29Si. This comprehensive survey covers the non-zero-spin nuclei relevant to direct dark matter detection. We include a pedagogical presentation of the formalism necessary to describe elastic and inelastic WIMP-nucleus scattering. The valence spaces and nuclear interactions employed have been previously used in nucl...

  9. Gaseous time projection chambers for rare event detection: results from the T-REX project. I. Double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Irastorza, I.G.; Aznar, F.; Castel, J., E-mail: igor.irastorza@cern.ch, E-mail: faznar@unizar.es, E-mail: jfcastel@unizar.es [Grupo de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C/ P. Cerbuna 12, Zaragoza, 50009 (Spain); and others

    2016-01-01

    As part of the T-REX project, a number of R and D and prototyping activities have been carried out during the last years to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches like double beta decay, axion research and low-mass WIMP searches. In both this and its companion paper, we compile the main results of the project and give an outlook of application prospects for this detection technique. While in the companion paper we focus on axions and WIMPs, in this paper we focus on the results regarding the measurement of the double beta decay (DBD) of {sup 136}Xe in a high pressure Xe (HPXe) TPC. Micromegas of the microbulk type have been extensively studied in high pressure Xe and Xe mixtures. Particularly relevant are the results obtained in Xe + trimethylamine (TMA) mixtures, showing very promising results in terms of gain, stability of operation, and energy resolution at high pressures up to 10 bar. The addition of TMA at levels of ∼ 1% reduces electron diffusion by up to a factor of 10 with respect to pure Xe, improving the quality of the topological pattern, with a positive impact on the discrimination capability. Operation with a medium size prototype of 30 cm diameter and 38 cm of drift (holding about 1 kg of Xe at 10 bar in the fiducial volume, enough to contain high energy electron tracks in the detector volume) has allowed to test the detection concept in realistic experimental conditions. Microbulk Micromegas are able to image the DBD ionization signature with high quality while, at the same time, measuring its energy deposition with a resolution of at least a ∼ 3% FWHM @ Q{sub ββ}. This value was experimentally demonstrated for high-energy extended tracks at 10 bar, and is probably improvable down to the ∼ 1% FWHM levels as extrapolated from low energy events. In addition, first results on the topological signature information (one straggling track ending in two

  10. Results and status of the Edelweiss Wimp search experiment; Experience Edelweiss de recherche directe de Wimps: resultats et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, A.; Berge, L.; Blumer, J.; Broniatowski, A.; Censier, B.; Chabert, L.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; Jesus, M. de; Drain, D.; Di Stefano, P.; Dumoulin, L.; Eitel, K.; Fesquet, M.; Firucci, S.; Gascon, J.; Gerbier, G.; Gerlic, E.; Goldbach, C.; Goyot, M.; Gros, M.; Habermahl, F.; Horn, M.; Hadjout, J.P.; Herve, S.; Juillard, A.; Kikuchi, C.; Lesquen, A. de; Luca, M.; Mallet, J.; Marnieros, S.; Martineau, O.; Mosca, L.; Navick, X.F.; Nollez, G.; Pari, P.; Riccio, C.; Sanglard, V.; Stern, M.; Vagneron, L.; Villard, V

    2005-07-01

    In the Edelweiss experiment, nuclear recoils induced by elastic collisions with WIMPs (weakly interacting massive particle) from the galactic halo are identified in low-temperature Ge detectors where the ratio of the heat and ionization signals provide an event-by-event discrimination of nuclear recoils from the dominant background coming from {gamma}-rays interactions. The Edelweiss experiment is located in the Modane underground facility in order to cut the muon flux drastically. We present here the results obtained during the first part of the experiment named Edelweiss-I that ended in the beginning of 2004. Since october 2002, 3 optimized 320 grams detectors have been simultaneously operated at a regulated temperature of 0.017 K and about 50 kg*day were added to the previous published data. These data are still under analysis but preliminary results concerning the upper limit at 90% CL (confidence level) confirm the limit already published in 2002. The first run of Edelweiss-II is due to begin during summer 2005, we are expecting to gain 2 orders of magnitude in terms of detector sensitivity and reach 0.002 events/day*kg. (A.C.)

  11. Identifying WIMP dark matter from particle and astroparticle data

    Science.gov (United States)

    Bertone, Gianfranco; Bozorgnia, Nassim; Kim, Jong Soo; Liem, Sebastian; McCabe, Christopher; Otten, Sydney; Ruiz de Austri, Roberto

    2018-03-01

    One of the most promising strategies to identify the nature of dark matter consists in the search for new particles at accelerators and with so-called direct detection experiments. Working within the framework of simplified models, and making use of machine learning tools to speed up statistical inference, we address the question of what we can learn about dark matter from a detection at the LHC and a forthcoming direct detection experiment. We show that with a combination of accelerator and direct detection data, it is possible to identify newly discovered particles as dark matter, by reconstructing their relic density assuming they are weakly interacting massive particles (WIMPs) thermally produced in the early Universe, and demonstrating that it is consistent with the measured dark matter abundance. An inconsistency between these two quantities would instead point either towards additional physics in the dark sector, or towards a non-standard cosmology, with a thermal history substantially different from that of the standard cosmological model.

  12. Science plumbs new depths in hunt for Wimps

    CERN Multimedia

    Benfield, C

    2003-01-01

    Lord Sainsbury has officially opened a laboratory in the salt mine at Boulby near Whitby. The lab is searching for WIMPs and was recently awarded 3.1 millions pounds by PPARC to upgrade the facility (1 page).

  13. WIMP-nucleon cross-section results from the second science run of ZEPLIN-III

    Energy Technology Data Exchange (ETDEWEB)

    Akimov, D.Yu. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Araujo, H.M., E-mail: h.araujo@imperial.ac.uk [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); Barnes, E.J. [School of Physics and Astronomy, SUPA University of Edinburgh (United Kingdom); Belov, V.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bewick, A. [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); Burenkov, A.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Chepel, V. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Currie, A. [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); DeViveiros, L. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Edwards, B. [Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Ghag, C.; Hollingsworth, A. [School of Physics and Astronomy, SUPA University of Edinburgh (United Kingdom); Horn, M.; Jones, W.G. [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); Kalmus, G.E. [Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Kobyakin, A.S.; Kovalenko, A.G. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Lebedenko, V.N. [High Energy Physics Group, Blackett Laboratory, Imperial College London (United Kingdom); Lindote, A. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Lopes, M.I. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); and others

    2012-03-13

    We report experimental upper limits on WIMP-nucleon elastic scattering cross sections from the second science run of ZEPLIN-III at the Boulby Underground Laboratory. A raw fiducial exposure of 1344 kg Dot-Operator days was accrued over 319 days of continuous operation between June 2010 and May 2011. A total of eight events was observed in the signal acceptance region in the nuclear recoil energy range 7-29 keV, which is compatible with background expectations. This allows the exclusion of the scalar cross-section above 4.8 Multiplication-Sign 10{sup -8} pb near 50 GeV/c{sup 2} WIMP mass with 90% confidence. Combined with data from the first run, this result improves to 3.9 Multiplication-Sign 10{sup -8} pb. The corresponding WIMP-neutron spin-dependent cross-section limit is 8.0 Multiplication-Sign 10{sup -3} pb. The ZEPLIN programme reaches thus its conclusion at Boulby, having deployed and exploited successfully three liquid xenon experiments of increasing reach.

  14. WIMP-nucleon cross-section results from the second science run of ZEPLIN-III

    International Nuclear Information System (INIS)

    Akimov, D.Yu.; Araújo, H.M.; Barnes, E.J.; Belov, V.A.; Bewick, A.; Burenkov, A.A.; Chepel, V.; Currie, A.; DeViveiros, L.; Edwards, B.; Ghag, C.; Hollingsworth, A.; Horn, M.; Jones, W.G.; Kalmus, G.E.; Kobyakin, A.S.; Kovalenko, A.G.; Lebedenko, V.N.; Lindote, A.; Lopes, M.I.

    2012-01-01

    We report experimental upper limits on WIMP-nucleon elastic scattering cross sections from the second science run of ZEPLIN-III at the Boulby Underground Laboratory. A raw fiducial exposure of 1344 kg⋅days was accrued over 319 days of continuous operation between June 2010 and May 2011. A total of eight events was observed in the signal acceptance region in the nuclear recoil energy range 7-29 keV, which is compatible with background expectations. This allows the exclusion of the scalar cross-section above 4.8×10 -8 pb near 50 GeV/c 2 WIMP mass with 90% confidence. Combined with data from the first run, this result improves to 3.9×10 -8 pb. The corresponding WIMP-neutron spin-dependent cross-section limit is 8.0×10 -3 pb. The ZEPLIN programme reaches thus its conclusion at Boulby, having deployed and exploited successfully three liquid xenon experiments of increasing reach.

  15. WIMP-nucleus scattering in chiral effective theory

    Science.gov (United States)

    Cirigliano, Vincenzo; Graesser, Michael L.; Ovanesyan, Grigory

    2012-10-01

    We discuss long-distance QCD corrections to the WIMP-nucleon(s) interactions in the framework of chiral effective theory. For scalar-mediated WIMP-quark interactions, we calculate all the next-to-leading-order corrections to the WIMP-nucleus elastic cross-section, including two-nucleon amplitudes and recoil-energy dependent shifts to the single-nucleon scalar form factors. As a consequence, the scalar-mediated WIMP-nucleus cross-section cannot be parameterized in terms of just two quantities, namely the neutron and proton scalar form factors at zero momentum transfer, but additional parameters appear, depending on the short-distance WIMP-quark interaction. Moreover, multiplicative factorization of the cross-section into particle, nuclear and astro-particle parts is violated. In practice, while the new effects are of the natural size expected by chiral power counting, they become very important in those regions of parameter space where the leading order WIMP-nucleus amplitude is suppressed, including the so-called "isospin-violating dark matter" regime. In these regions of parameter space we find order-of-magnitude corrections to the total scattering rates and qualitative changes to the shape of recoil spectra.

  16. Detecting surface events at the COBRA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tebruegge, Jan [Exp. Physik IV, TU Dortmund (Germany); Collaboration: COBRA-Collaboration

    2015-07-01

    The aim of the COBRA experiment is to prove the existence of neutrinoless double-beta-decay and to measure its half-life. For this purpose the COBRA demonstrator, a prototype for a large-scale experiment, is operated at the Gran Sasso Underground Laboratory (LNGS) in Italy. The demonstrator is a detector array made of 64 Cadmium-Zinc-Telluride (CdZnTe) semiconductor detectors in the coplanar grid anode configuration. Each detector is 1**1 ccm in size. This setup is used to investigate the experimental issues of operating CdZnTe detectors in low background mode and identify potential background components. As the ''detector=source'' principle is used, the neutrinoless double beta decay COBRA searches for happens within the whole detector volume. Consequently, events on the surface of the detectors are considered as background. These surface events are a main background component, stemming mainly from the natural radioactivity, especially radon. This talk explains to what extent surface events occur and shows how these are recognized and vetoed in the analysis using pulse shape discrimination algorithms.

  17. Subsurface Event Detection and Classification Using Wireless Signal Networks

    Directory of Open Access Journals (Sweden)

    Muhannad T. Suleiman

    2012-11-01

    Full Text Available Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs. The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events.

  18. Subsurface event detection and classification using Wireless Signal Networks.

    Science.gov (United States)

    Yoon, Suk-Un; Ghazanfari, Ehsan; Cheng, Liang; Pamukcu, Sibel; Suleiman, Muhannad T

    2012-11-05

    Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs). The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events.

  19. Learning Multimodal Deep Representations for Crowd Anomaly Event Detection

    Directory of Open Access Journals (Sweden)

    Shaonian Huang

    2018-01-01

    Full Text Available Anomaly event detection in crowd scenes is extremely important; however, the majority of existing studies merely use hand-crafted features to detect anomalies. In this study, a novel unsupervised deep learning framework is proposed to detect anomaly events in crowded scenes. Specifically, low-level visual features, energy features, and motion map features are simultaneously extracted based on spatiotemporal energy measurements. Three convolutional restricted Boltzmann machines are trained to model the mid-level feature representation of normal patterns. Then a multimodal fusion scheme is utilized to learn the deep representation of crowd patterns. Based on the learned deep representation, a one-class support vector machine model is used to detect anomaly events. The proposed method is evaluated using two available public datasets and compared with state-of-the-art methods. The experimental results show its competitive performance for anomaly event detection in video surveillance.

  20. Exclusion limits on the WIMP-nucleon cross section from the first run of the Cryogenic Dark Matter Search in the Soudan Underground Laboratory

    International Nuclear Information System (INIS)

    Akerib, D.S.; Bailey, C.N.; Dragowsky, M.R.; Driscoll, D.D.; Hennings-Yeomans, R.; Kamat, S.; Perera, T.A.; Schnee, R.W.; Wang, G.; Armel-Funkhouser, M.S.; Daal, M.; Filippini, J.; Lu, A.; Mandic, V.; Meunier, P.; Mirabolfathi, N.; Issac, M.C. Perillo; Rau, W.; Seitz, D.N.; Serfass, B.

    2005-01-01

    The Cryogenic Dark Matter Search (CDMS-II) employs low-temperature Ge and Si detectors to seek weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei. Simultaneous measurements of both ionization and phonon energy provide discrimination against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.99% efficiency. Electromagnetic events very near the detector surface can mimic nuclear recoils because of reduced charge collection, but these surface events are rejected with >96% efficiency by using additional information from the phonon pulse shape. Efficient use of active and passive shielding, combined with the 2090 m.w.e. overburden at the experimental site in the Soudan mine, makes the background from neutrons negligible for this first exposure. All cuts are determined in a blind manner from in situ calibrations with external radioactive sources without any prior knowledge of the event distribution in the signal region. Resulting efficiencies are known to ∼10%. A single event with a recoil of 64 keV passes all of the cuts and is consistent with the expected misidentification rate of surface electron recoils. Under the assumptions for a standard dark matter halo, these data exclude previously unexplored parameter space for both spin-independent and spin-dependent WIMP-nucleon elastic scattering. The resulting limit on the spin-independent WIMP-nucleon elastic-scattering cross section has a minimum of 4x10 -43 cm 2 at a WIMP mass of 60 GeVc -2 . The minimum of the limit for the spin-dependent WIMP-neutron elastic-scattering cross section is 2x10 -37 cm 2 at a WIMP mass of 50 GeVc -2

  1. Abnormal global and local event detection in compressive sensing domain

    Science.gov (United States)

    Wang, Tian; Qiao, Meina; Chen, Jie; Wang, Chuanyun; Zhang, Wenjia; Snoussi, Hichem

    2018-05-01

    Abnormal event detection, also known as anomaly detection, is one challenging task in security video surveillance. It is important to develop effective and robust movement representation models for global and local abnormal event detection to fight against factors such as occlusion and illumination change. In this paper, a new algorithm is proposed. It can locate the abnormal events on one frame, and detect the global abnormal frame. The proposed algorithm employs a sparse measurement matrix designed to represent the movement feature based on optical flow efficiently. Then, the abnormal detection mission is constructed as a one-class classification task via merely learning from the training normal samples. Experiments demonstrate that our algorithm performs well on the benchmark abnormal detection datasets against state-of-the-art methods.

  2. Abnormal global and local event detection in compressive sensing domain

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2018-05-01

    Full Text Available Abnormal event detection, also known as anomaly detection, is one challenging task in security video surveillance. It is important to develop effective and robust movement representation models for global and local abnormal event detection to fight against factors such as occlusion and illumination change. In this paper, a new algorithm is proposed. It can locate the abnormal events on one frame, and detect the global abnormal frame. The proposed algorithm employs a sparse measurement matrix designed to represent the movement feature based on optical flow efficiently. Then, the abnormal detection mission is constructed as a one-class classification task via merely learning from the training normal samples. Experiments demonstrate that our algorithm performs well on the benchmark abnormal detection datasets against state-of-the-art methods.

  3. Event storm detection and identification in communication systems

    International Nuclear Information System (INIS)

    Albaghdadi, Mouayad; Briley, Bruce; Evens, Martha

    2006-01-01

    Event storms are the manifestation of an important class of abnormal behaviors in communication systems. They occur when a large number of nodes throughout the system generate a set of events within a small period of time. It is essential for network management systems to detect every event storm and identify its cause, in order to prevent and repair potential system faults. This paper presents a set of techniques for the effective detection and identification of event storms in communication systems. First, we introduce a new algorithm to synchronize events to a single node in the system. Second, the system's event log is modeled as a normally distributed random process. This is achieved by using data analysis techniques to explore and then model the statistical behavior of the event log. Third, event storm detection is proposed using a simple test statistic combined with an exponential smoothing technique to overcome the non-stationary behavior of event logs. Fourth, the system is divided into non-overlapping regions to locate the main contributing regions of a storm. We show that this technique provides us with a method for event storm identification. Finally, experimental results from a commercially deployed multimedia communication system that uses these techniques demonstrate their effectiveness

  4. A Search for WIMP Dark Matter Using an Optimized Chi-square Technique on the Final Data from the Cryogenic Dark Matter Search Experiment (CDMS II)

    Energy Technology Data Exchange (ETDEWEB)

    Manungu Kiveni, Joseph [Syracuse Univ., NY (United States)

    2012-12-01

    This dissertation describes the results of a WIMP search using CDMS II data sets accumulated at the Soudan Underground Laboratory in Minnesota. Results from the original analysis of these data were published in 2009; two events were observed in the signal region with an expected leakage of 0.9 events. Further investigation revealed an issue with the ionization-pulse reconstruction algorithm leading to a software upgrade and a subsequent reanalysis of the data. As part of the reanalysis, I performed an advanced discrimination technique to better distinguish (potential) signal events from backgrounds using a 5-dimensional chi-square method. This dataanalysis technique combines the event information recorded for each WIMP-search event to derive a backgrounddiscrimination parameter capable of reducing the expected background to less than one event, while maintaining high efficiency for signal events. Furthermore, optimizing the cut positions of this 5-dimensional chi-square parameter for the 14 viable germanium detectors yields an improved expected sensitivity to WIMP interactions relative to previous CDMS results. This dissertation describes my improved (and optimized) discrimination technique and the results obtained from a blind application to the reanalyzed CDMS II WIMP-search data.

  5. Detecting failure events in buildings: a numerical and experimental analysis

    OpenAIRE

    Heckman, V. M.; Kohler, M. D.; Heaton, T. H.

    2010-01-01

    A numerical method is used to investigate an approach for detecting the brittle fracture of welds associated with beam -column connections in instrumented buildings in real time through the use of time-reversed Green’s functions and wave propagation reciprocity. The approach makes use of a prerecorded catalog of Green’s functions for an instrumented building to detect failure events in the building during a later seismic event by screening continuous data for the presence of wavef...

  6. Online Detection of Abnormal Events in Video Streams

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2013-01-01

    an image descriptor and online nonlinear classification method. We introduce the covariance matrix of the optical flow and image intensity as a descriptor encoding moving information. The nonlinear online support vector machine (SVM firstly learns a limited set of the training frames to provide a basic reference model then updates the model and detects abnormal events in the current frame. We finally apply the method to detect abnormal events on a benchmark video surveillance dataset to demonstrate the effectiveness of the proposed technique.

  7. The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

    International Nuclear Information System (INIS)

    Wang, Gen-sheng

    2005-01-01

    Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particle physics. The Cryogenic Dark Matter Search (CDMS) experiment is searching for evidence of a WIMP interaction off an atomic nucleus in crystals of Ge and Si by measuring simultaneously the phonon energy and ionization energy of the interaction in the CDMS detectors. The WIMP interaction energy is from a few keV to tens of keV with a rate less than 0.1 events/kg/day. To reach the goal of WIMP detection, the CDMS experiment has been conducted in the Soudan mine with an active muon veto and multistage passive background shields. The CDMS detectors have a low energy threshold and background rejection capabilities based on ionization yield. However, betas from contamination and other radioactive sources produce surface interactions, which have low ionization yield, comparable to that of bulk nuclear interactions. The low-ionization surface electron recoils must be removed in the WIMP search data analysis. An emphasis of this thesis is on developing the method of the surface-interaction rejection using location information of the interactions, phonon energy distributions and phonon timing parameters. The result of the CDMS Soudan run118 92.3 live day WIMP search data analysis is presented, and represents the most sensitive search yet performed

  8. The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gensheng [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Physics

    2005-01-01

    Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particle physics. The Cryogenic Dark Matter Search (CDMS) experiment is searching for evidence of a WIMP interaction off an atomic nucleus in crystals of Ge and Si by measuring simultaneously the phonon energy and ionization energy of the interaction in the CDMS detectors. The WIMP interaction energy is from a few keV to tens of keV with a rate less than 0.1 events/kg/day. To reach the goal of WIMP detection, the CDMS experiment has been conducted in the Soudan mine with an active muon veto and multistage passive background shields. The CDMS detectors have a low energy threshold and background rejection capabilities based on ionization yield. However, betas from contamination and other radioactive sources produce surface interactions, which have low ionization yield, comparable to that of bulk nuclear interactions. The low-ionization surface electron recoils must be removed in the WIMP search data analysis. An emphasis of this thesis is on developing the method of the surface-interaction rejection using location information of the interactions, phonon energy distributions and phonon timing parameters. The result of the CDMS Soudan run118 92.3 live day WIMP search data analysis is presented, and represents the most sensitive search yet performed.

  9. Search for WIMP dark matter produced in association with a Z boson with the ATLAS detector

    CERN Document Server

    Basalaev, Artem; The ATLAS collaboration

    2016-01-01

    The search for weakly interacting dark matter particle (WIMP) candidates produced in association with a Z boson is presented. Events with large missing transverse momentum and consistent with the decay of a Z boson into oppositely charged electron or muon pairs were selected in analysis. Background estimates and corresponding systematic uncertainties are shown. The limits on the mass scale of the contact interaction as a function of the dark matter particle mass and the limits on the coupling and scalar particle mediator mass for 8 TeV proton-proton collisions data are presented. Prospects for analysis using 13 TeV proton-proton collisions data are discussed.

  10. Proceedings of the 4th Patras workshop on axions, WIMPs and WISPs

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, Axel; Redondo, Javier; Ringwald, Andreas [eds.

    2008-08-15

    The following topics were dealt with: Physical foundations for WIMPs, axions, and WISPS, signals from astrophysical sources, direct searches for dark matter WIMPs, new theoretical developments, new experimental approaches. (HSI)

  11. Proceedings of the 4th Patras workshop on axions, WIMPs and WISPs

    International Nuclear Information System (INIS)

    Lindner, Axel; Redondo, Javier; Ringwald, Andreas

    2008-08-01

    The following topics were dealt with: Physical foundations for WIMPs, axions, and WISPS, signals from astrophysical sources, direct searches for dark matter WIMPs, new theoretical developments, new experimental approaches. (HSI)

  12. Non-Linguistic Vocal Event Detection Using Online Random

    DEFF Research Database (Denmark)

    Abou-Zleikha, Mohamed; Tan, Zheng-Hua; Christensen, Mads Græsbøll

    2014-01-01

    areas such as object detection, face recognition, and audio event detection. This paper proposes to use online random forest technique for detecting laughter and filler and for analyzing the importance of various features for non-linguistic vocal event classification through permutation. The results...... show that according to the Area Under Curve measure the online random forest achieved 88.1% compared to 82.9% obtained by the baseline support vector machines for laughter classification and 86.8% to 83.6% for filler classification....

  13. TACKLING EVENT DETECTION IN THE CONTEXT OF VIDEO SURVEILLANCE

    Directory of Open Access Journals (Sweden)

    Raducu DUMITRESCU

    2011-11-01

    Full Text Available In this paper we address the problem of event detection in the context of video surveillance systems. First we deal with background extraction. Three methods are being tested, namely: frame differencing, running average and an estimate of median filtering technique. This provides information about changing contents. Further, we use this information to address human presence detection in the scene. This is carried out thought a contour-based approach. Contours are extracted from moving regions and parameterized. Human silhouettes show particular signatures of these parameters. Experimental results prove the potential of this approach to event detection. However, these are our first preliminary results to this application.

  14. Event Coverage Detection and Event Source Determination in Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zhangbing Zhou

    2015-12-01

    Full Text Available With the advent of the Internet of Underwater Things, smart things are deployed in the ocean space and establish underwater wireless sensor networks for the monitoring of vast and dynamic underwater environments. When events are found to have possibly occurred, accurate event coverage should be detected, and potential event sources should be determined for the enactment of prompt and proper responses. To address this challenge, a technique that detects event coverage and determines event sources is developed in this article. Specifically, the occurrence of possible events corresponds to a set of neighboring sensor nodes whose sensory data may deviate from a normal sensing range in a collective fashion. An appropriate sensor node is selected as the relay node for gathering and routing sensory data to sink node(s. When sensory data are collected at sink node(s, the event coverage is detected and represented as a weighted graph, where the vertices in this graph correspond to sensor nodes and the weight specified upon the edges reflects the extent of sensory data deviating from a normal sensing range. Event sources are determined, which correspond to the barycenters in this graph. The results of the experiments show that our technique is more energy efficient, especially when the network topology is relatively steady.

  15. COMPARISON OF FOUR METHODS TO DETECT ADVERSE EVENTS IN HOSPITAL

    Directory of Open Access Journals (Sweden)

    Inge Dhamanti

    2015-09-01

    Full Text Available AbstrakDeteksi terjadinya kejadian yang tidak diharapkan (KTD telah menjadi salah satu tantangan dalam keselamatan pasien oleh karena itu metode untuk mendeteksi terjadinya KTD sangatlah penting untuk meningkatkan keselamatan pasien. Tujuan dari artikel ini adalah untuk membandingkan kelebihan dan kekurangan dari beberapa metode untuk mendeteksi terjadinya KTD di rumah sakit, meliputi review rekam medis, pelaporan insiden secara mandiri, teknologi informasi, dan pelaporan oleh pasien. Studi ini merupakan kajian literatur untuk membandingkan dan menganalisa metode terbaik untuk mendeteksi KTD yang dapat diimplementasikan oleh rumah sakit. Semua dari empat metode telah terbukti mampu untuk mendeteksi terjadinya KTD di rumah sakit, tetapi masing-masing metode mempunyai kelebihan dan kekurangan yang perlu diatasi. Tidak ada satu metode terbaik yang akan memberikan hasil terbaik untuk mendeteksi KTD di rumah sakit. Sehingga untuk mendeteksi lebih banyak KTD yang seharusnya dapat dicegah, atau KTD yang telah terjadi, rumah sakit seharusnya mengkombinasikan lebih dari satu metode untuk mendeteksi, karena masing-masing metode mempunyai sensitivitas berbeda-beda.AbstractDetecting adverse events has become one of the challenges in patient safety thus methods to detect adverse events become critical for improving patient safety. The purpose of this paper is to compare the strengths and weaknesses of several methods of identifying adverse events in hospital, including medical records reviews, self-reported incidents, information technology, and patient self-reports. This study is a literature review to compared and analyzed to determine the best method implemented by the hospital. All of four methods have been proved in their ability in detecting adverse events in hospitals, but each method had strengths and limitations to be overcome. There is no ‘best’ single method that will give the best results for adverse events detection in hospital. Thus to

  16. An Examination of Three Spatial Event Cluster Detection Methods

    Directory of Open Access Journals (Sweden)

    Hensley H. Mariathas

    2015-03-01

    Full Text Available In spatial disease surveillance, geographic areas with large numbers of disease cases are to be identified, so that targeted investigations can be pursued. Geographic areas with high disease rates are called disease clusters and statistical cluster detection tests are used to identify geographic areas with higher disease rates than expected by chance alone. In some situations, disease-related events rather than individuals are of interest for geographical surveillance, and methods to detect clusters of disease-related events are called event cluster detection methods. In this paper, we examine three distributional assumptions for the events in cluster detection: compound Poisson, approximate normal and multiple hypergeometric (exact. The methods differ on the choice of distributional assumption for the potentially multiple correlated events per individual. The methods are illustrated on emergency department (ED presentations by children and youth (age < 18 years because of substance use in the province of Alberta, Canada, during 1 April 2007, to 31 March 2008. Simulation studies are conducted to investigate Type I error and the power of the clustering methods.

  17. Analytic 3D image reconstruction using all detected events

    International Nuclear Information System (INIS)

    Kinahan, P.E.; Rogers, J.G.

    1988-11-01

    We present the results of testing a previously presented algorithm for three-dimensional image reconstruction that uses all gamma-ray coincidence events detected by a PET volume-imaging scanner. By using two iterations of an analytic filter-backprojection method, the algorithm is not constrained by the requirement of a spatially invariant detector point spread function, which limits normal analytic techniques. Removing this constraint allows the incorporation of all detected events, regardless of orientation, which improves the statistical quality of the final reconstructed image

  18. Spatial-Temporal Event Detection from Geo-Tagged Tweets

    Directory of Open Access Journals (Sweden)

    Yuqian Huang

    2018-04-01

    Full Text Available As one of the most popular social networking services in the world, Twitter allows users to post messages along with their current geographic locations. Such georeferenced or geo-tagged Twitter datasets can benefit location-based services, targeted advertising and geosocial studies. Our study focused on the detection of small-scale spatial-temporal events and their textual content. First, we used Spatial-Temporal Density-Based Spatial Clustering of Applications with Noise (ST-DBSCAN to spatially-temporally cluster the tweets. Then, the word frequencies were summarized for each cluster and the potential topics were modeled by the Latent Dirichlet Allocation (LDA algorithm. Using two years of Twitter data from four college cities in the U.S., we were able to determine the spatial-temporal patterns of two known events, two unknown events and one recurring event, which then were further explored and modeled to identify the semantic content about the events. This paper presents our process and recommendations for both finding event-related tweets as well as understanding the spatial-temporal behaviors and semantic natures of the detected events.

  19. No WIMP mini-spikes in dwarf spheroidal galaxies

    NARCIS (Netherlands)

    Wanders, M.; Bertone, G.; Volonteri, M.; Weniger, C.

    2015-01-01

    The formation of black holes inevitably affects the distribution of dark and baryonic matter in their vicinity, leading to an enhancement of the dark matter density, called spike, and if dark matter is made of WIMPs, to a strong enhancement of the dark matter annihilation rate. Spikes at the center

  20. Dark Matter: Looking for WIMPs in the Galactic Halo

    International Nuclear Information System (INIS)

    Akerib, Daniel S.

    2006-01-01

    Overwhelming observational evidence indicates that most of the matter in the Universe consists of non-baryonic dark matter. One possibility is that the dark matter is Weakly-Interacting Massive Particles (WIMPs) that were produced in the early Universe. These relics could comprise the Milky Way's dark halo and provide evidence for new particle physics, such as Supersymmetry. After reviewing some of the evidence for dark matter and the WIMP hypothesis, I will describe the strategy for searching for WIMPs, along with a survey of the current status and outlook. In particular, dark matter searches have begun to explore the region of parameter space where SUSY particles could provide dark matter candidates. I will also mention some of the recent theoretical work on dark matter candidates which is being done in anticipation of the turn-on of the LHC and as part of the active R and D on the ILC. Finally, a vigorous detector development program promises significant advances in WIMP sensitivity in the coming years

  1. Event-Triggered Fault Detection of Nonlinear Networked Systems.

    Science.gov (United States)

    Li, Hongyi; Chen, Ziran; Wu, Ligang; Lam, Hak-Keung; Du, Haiping

    2017-04-01

    This paper investigates the problem of fault detection for nonlinear discrete-time networked systems under an event-triggered scheme. A polynomial fuzzy fault detection filter is designed to generate a residual signal and detect faults in the system. A novel polynomial event-triggered scheme is proposed to determine the transmission of the signal. A fault detection filter is designed to guarantee that the residual system is asymptotically stable and satisfies the desired performance. Polynomial approximated membership functions obtained by Taylor series are employed for filtering analysis. Furthermore, sufficient conditions are represented in terms of sum of squares (SOSs) and can be solved by SOS tools in MATLAB environment. A numerical example is provided to demonstrate the effectiveness of the proposed results.

  2. Detection of Abnormal Events via Optical Flow Feature Analysis

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2015-03-01

    Full Text Available In this paper, a novel algorithm is proposed to detect abnormal events in video streams. The algorithm is based on the histogram of the optical flow orientation descriptor and the classification method. The details of the histogram of the optical flow orientation descriptor are illustrated for describing movement information of the global video frame or foreground frame. By combining one-class support vector machine and kernel principal component analysis methods, the abnormal events in the current frame can be detected after a learning period characterizing normal behaviors. The difference abnormal detection results are analyzed and explained. The proposed detection method is tested on benchmark datasets, then the experimental results show the effectiveness of the algorithm.

  3. Detection of Abnormal Events via Optical Flow Feature Analysis

    Science.gov (United States)

    Wang, Tian; Snoussi, Hichem

    2015-01-01

    In this paper, a novel algorithm is proposed to detect abnormal events in video streams. The algorithm is based on the histogram of the optical flow orientation descriptor and the classification method. The details of the histogram of the optical flow orientation descriptor are illustrated for describing movement information of the global video frame or foreground frame. By combining one-class support vector machine and kernel principal component analysis methods, the abnormal events in the current frame can be detected after a learning period characterizing normal behaviors. The difference abnormal detection results are analyzed and explained. The proposed detection method is tested on benchmark datasets, then the experimental results show the effectiveness of the algorithm. PMID:25811227

  4. Event detection for car park entries by video-surveillance

    Science.gov (United States)

    Coquin, Didier; Tailland, Johan; Cintract, Michel

    2007-10-01

    Intelligent surveillance has become an important research issue due to the high cost and low efficiency of human supervisors, and machine intelligence is required to provide a solution for automated event detection. In this paper we describe a real-time system that has been used for detecting car park entries, using an adaptive background learning algorithm and two indicators representing activity and identity to overcome the difficulty of tracking objects.

  5. Cryogenic scintillators for rare events detection in the Edelweiss and EURECA experiments

    International Nuclear Information System (INIS)

    Verdier, M.A.

    2010-10-01

    The riddle of the dark matter in astrophysics could be solved by the detection of WIMPs (Weakly Interactive Massive Particles), particles that are predicted by supersymmetry. The direct detection of WIMPs requires a large mass of detectors, able to identify these particles in the background of natural radioactivity and cosmic rays. This thesis takes place within the framework of the EDELWEISS and the future EURECA experiments. These experiments use a technology based on two channel cryogenic detectors (bolometers), working at a few tens of mK. They are composed of crystals in which the energy deposited by particle interactions will produce a temperature increase (phonon signal), and where the ionization of the crystals results in either a charge or photon signal, depending on their nature. In order to broaden the range of targets for scintillating bolometers, we have built a setup to study the scintillation of crystals cooled down to 3 K. It is based on a cryostat with a compact optical geometry allowing enhanced light collection. Thanks to an individual photon counting technique and a statistical treatment of data, it allows us to measure the evolution of the the light yields and the decay time components between room temperature and 3 K. Thus this thesis presents the results obtained at 3 K on two well known room temperature crystals: BGO (Bi 4 Ge 3 O 12 ) and BaF 2 . We also study the luminescence properties of titanium sapphire (Ti:Al 2 O 3 ), under VUV excitation cooled down to 8 K. (author)

  6. Constraints on light WIMP candidates from the isotropic diffuse gamma-ray emission

    International Nuclear Information System (INIS)

    Arina, Chiara; Tytgat, Michel H.G.

    2011-01-01

    Motivated by the measurements reported by direct detection experiments, most notably DAMA, CDMS-II, CoGeNT and Xenon10/100, we study further the constraints that might be set on some light dark matter candidates, M DM ∼ few GeV, using the Fermi-LAT data on the isotropic gamma-ray diffuse emission. In particular, we consider a Dirac fermion singlet interacting through a new Z' gauge boson, and a scalar singlet S interacting through the Higgs portal. Both candidates are WIMP (Weakly Interacting Massive Particles), i.e. they have an annihilation cross-section in the pbarn range. Also they may both have a spin-independent elastic cross section on nucleons in the range required by direct detection experiments. Although being generic WIMP candidates, because they have different interactions with Standard Model particles, their phenomenology regarding the isotropic diffuse gamma-ray emission is quite distinct. In the case of the scalar singlet, the one-to-one correspondence between its annihilation cross-section and its spin-independent elastic scattering cross-section permits to express the constraints from the Fermi-LAT data in the direct detection exclusion plot, σ n 0 −M DM . Depending on the astrophysics, we argue that it is possible to exclude the singlet scalar dark matter candidate at 95% confidence level. The constraints on the Dirac singlet interacting through a Z' are comparatively weaker

  7. Context-aware event detection smartphone application for first responders

    Science.gov (United States)

    Boddhu, Sanjay K.; Dave, Rakesh P.; McCartney, Matt; West, James A.; Williams, Robert L.

    2013-05-01

    The rise of social networking platforms like Twitter, Facebook, etc…, have provided seamless sharing of information (as chat, video and other media) among its user community on a global scale. Further, the proliferation of the smartphones and their connectivity networks has powered the ordinary individuals to share and acquire information regarding the events happening in his/her immediate vicinity in a real-time fashion. This human-centric sensed data being generated in "human-as-sensor" approach is tremendously valuable as it delivered mostly with apt annotations and ground truth that would be missing in traditional machine-centric sensors, besides high redundancy factor (same data thru multiple users). Further, when appropriately employed this real-time data can support in detecting localized events like fire, accidents, shooting, etc…, as they unfold and pin-point individuals being affected by those events. This spatiotemporal information, when made available for first responders in the event vicinity (or approaching it) can greatly assist them to make effective decisions to protect property and life in a timely fashion. In this vein, under SATE and YATE programs, the research team at AFRL Tec^Edge Discovery labs had demonstrated the feasibility of developing Smartphone applications, that can provide a augmented reality view of the appropriate detected events in a given geographical location (localized) and also provide an event search capability over a large geographic extent. In its current state, the application thru its backend connectivity utilizes a data (Text & Image) processing framework, which deals with data challenges like; identifying and aggregating important events, analyzing and correlating the events temporally and spatially and building a search enabled event database. Further, the smartphone application with its backend data processing workflow has been successfully field tested with live user generated feeds.

  8. TNO at TRECVID 2013: Multimedia Event Detection and Instance Search

    NARCIS (Netherlands)

    Bouma, H.; Azzopardi, G.; Spitters, M.M.; Wit, J.J. de; Versloot, C.A.; Zon, R.W.L. van der; Eendebak, P.T.; Baan, J.; Hove, R.J.M. ten; Eekeren, A.W.M. van; Haar, F.B. ter; Hollander, R.J.M. den; Huis, R.J. van; Boer, M.H.T. de; Antwerpen, G. van; Broekhuijsen, B.J.; Daniele, L.M.; Brandt, P.; Schavemaker, J.G.M.; Kraaij, W.; Schutte, K.

    2013-01-01

    We describe the TNO system and the evaluation results for TRECVID 2013 Multimedia Event Detection (MED) and instance search (INS) tasks. The MED system consists of a bag-of-word (BOW) approach with spatial tiling that uses low-level static and dynamic visual features, an audio feature and high-level

  9. Distributed Event Detection in Wireless Sensor Networks for Disaster Management

    NARCIS (Netherlands)

    Bahrepour, M.; Meratnia, Nirvana; Poel, Mannes; Taghikhaki, Zahra; Havinga, Paul J.M.

    2010-01-01

    Recently, wireless sensor networks (WSNs) have become mature enough to go beyond being simple fine-grained continuous monitoring platforms and become one of the enabling technologies for disaster early-warning systems. Event detection functionality of WSNs can be of great help and importance for

  10. Complex Event Detection via Multi Source Video Attributes (Open Access)

    Science.gov (United States)

    2013-10-03

    Complex Event Detection via Multi-Source Video Attributes Zhigang Ma† Yi Yang‡ Zhongwen Xu‡§ Shuicheng Yan Nicu Sebe† Alexander G. Hauptmann...under its International Research Centre @ Singapore Fund- ing Initiative and administered by the IDM Programme Of- fice, and the Intelligence Advanced

  11. On Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Suresh, Mahima Agumbe

    2013-05-01

    Acyclic flow networks, present in many infrastructures of national importance (e.g., oil and gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against these infrastructures have been proven costly and imprecise, particularly when dealing with large-scale distribution systems. In this article, to the best of our knowledge, for the first time, we investigate how mobile sensor networks can be used for optimal event detection and localization in acyclic flow networks. We propose the idea of using sensors that move along the edges of the network and detect events (i.e., attacks). To localize the events, sensors detect proximity to beacons, which are devices with known placement in the network. We formulate the problem of minimizing the cost of monitoring infrastructure (i.e., minimizing the number of sensors and beacons deployed) in a predetermined zone of interest, while ensuring a degree of coverage by sensors and a required accuracy in locating events using beacons. We propose algorithms for solving the aforementioned problem and demonstrate their effectiveness with results obtained from a realistic flow network simulator.

  12. National Earthquake Information Center Seismic Event Detections on Multiple Scales

    Science.gov (United States)

    Patton, J.; Yeck, W. L.; Benz, H.; Earle, P. S.; Soto-Cordero, L.; Johnson, C. E.

    2017-12-01

    The U.S. Geological Survey National Earthquake Information Center (NEIC) monitors seismicity on local, regional, and global scales using automatic picks from more than 2,000 near-real time seismic stations. This presents unique challenges in automated event detection due to the high variability in data quality, network geometries and density, and distance-dependent variability in observed seismic signals. To lower the overall detection threshold while minimizing false detection rates, NEIC has begun to test the incorporation of new detection and picking algorithms, including multiband (Lomax et al., 2012) and kurtosis (Baillard et al., 2014) pickers, and a new bayesian associator (Glass 3.0). The Glass 3.0 associator allows for simultaneous processing of variably scaled detection grids, each with a unique set of nucleation criteria (e.g., nucleation threshold, minimum associated picks, nucleation phases) to meet specific monitoring goals. We test the efficacy of these new tools on event detection in networks of various scales and geometries, compare our results with previous catalogs, and discuss lessons learned. For example, we find that on local and regional scales, rapid nucleation of small events may require event nucleation with both P and higher-amplitude secondary phases (e.g., S or Lg). We provide examples of the implementation of a scale-independent associator for an induced seismicity sequence (local-scale), a large aftershock sequence (regional-scale), and for monitoring global seismicity. Baillard, C., Crawford, W. C., Ballu, V., Hibert, C., & Mangeney, A. (2014). An automatic kurtosis-based P-and S-phase picker designed for local seismic networks. Bulletin of the Seismological Society of America, 104(1), 394-409. Lomax, A., Satriano, C., & Vassallo, M. (2012). Automatic picker developments and optimization: FilterPicker - a robust, broadband picker for real-time seismic monitoring and earthquake early-warning, Seism. Res. Lett. , 83, 531-540, doi: 10

  13. Towards Detecting the Crowd Involved in Social Events

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2017-10-01

    Full Text Available Knowing how people interact with urban environments is fundamental for a variety of fields, ranging from transportation to social science. Despite the fact that human mobility patterns have been a major topic of study in recent years, a challenge to understand large-scale human behavior when a certain event occurs remains due to a lack of either relevant data or suitable approaches. Psychological crowd refers to a group of people who are usually located at different places and show different behaviors, but who are very sensitively driven to take the same act (gather together by a certain event, which has been theoretically studied by social psychologists since the 19th century. This study aims to propose a computational approach using a machine learning method to model psychological crowds, contributing to the better understanding of human activity patterns under events. Psychological features and mental unity of the crowd are computed to detect the involved individuals. A national event happening across the USA in April, 2015 is analyzed using geotagged tweets as a case study to test our approach. The result shows that 81% of individuals in the crowd can be successfully detected. Through investigating the geospatial pattern of the involved users, not only can the event related users be identified but also those unobserved users before the event can be uncovered. The proposed approach can effectively represent the psychological feature and measure the mental unity of the psychological crowd, which sheds light on the study of large-scale psychological crowd and provides an innovative way to understanding human behavior under events.

  14. Neutron detector for detecting rare events of spontaneous fission

    International Nuclear Information System (INIS)

    Ter-Akop'yan, G.M.; Popeko, A.G.; Sokol, E.A.; Chelnokov, L.P.; Smirnov, V.I.; Gorshkov, V.A.

    1981-01-01

    The neutron detector for registering rare events of spontaneous fission by detecting multiple neutron emission is described. The detector represents a block of plexiglas of 550 mm diameter and 700 mm height in the centre of which there is a through 160 mm diameter channel for the sample under investigation. The detector comprises 56 3 He filled counters (up to 7 atm pressure) with 1% CO 2 addition. The counters have a 500 mm length and a 32 mm diameter. The sampling of fission events is realized by an electron system which allows determining the number of detected neutrons, numbers of operated counters, signal amplitude and time for fission event detecting. A block diagram of a neutron detector electron system is presented and its operation principle is considered. For protection against cosmic radiation the detector is surronded by a system of plastic scintillators and placed behind the concrete shield of 6 m thickness. The results of measurements of background radiation are given. It has been found that the background radiation of single neutron constitutes about 150 counts per hour, the detecting efficiency of single neutron equals 0.483 +- 0.005, for a 10l detector sensitive volume. By means of the detector described the parameters of multiplicity distribution of prompt neutrons for 256 Fm spontaneous fission are measured. The average multiplicity equals 3.59+-0.06 the dispersion being 2.30+-0.65

  15. Detection and interpretation of seismoacoustic events at German infrasound stations

    Science.gov (United States)

    Pilger, Christoph; Koch, Karl; Ceranna, Lars

    2016-04-01

    Three infrasound arrays with collocated or nearby installed seismometers are operated by the Federal Institute for Geosciences and Natural Resources (BGR) as the German National Data Center (NDC) for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Infrasound generated by seismoacoustic events is routinely detected at these infrasound arrays, but air-to-ground coupled acoustic waves occasionally show up in seismometer recordings as well. Different natural and artificial sources like meteoroids as well as industrial and mining activity generate infrasonic signatures that are simultaneously detected at microbarometers and seismometers. Furthermore, many near-surface sources like earthquakes and explosions generate both seismic and infrasonic waves that can be detected successively with both technologies. The combined interpretation of seismic and acoustic signatures provides additional information about the origin time and location of remote infrasound events or about the characterization of seismic events distinguishing man-made and natural origins. Furthermore, seismoacoustic studies help to improve the modelling of infrasound propagation and ducting in the atmosphere and allow quantifying the portion of energy coupled into ground and into air by seismoacoustic sources. An overview of different seismoacoustic sources and their detection by German infrasound stations as well as some conclusions on the benefit of a combined seismoacoustic analysis are presented within this study.

  16. Theoretical interpretation of experimental data from direct dark matter detection

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Lin, Shan

    2007-10-15

    I derive expressions that allow to reconstruct the normalized one-dimensional velocity distribution function of halo WIMPs and to determine its moments from the recoil energy spectrum as well as from experimental data directly. The reconstruction of the velocity distribution function is further extended to take into account the annual modulation of the event rate. All these expressions are independent of the as yet unknown WIMP density near the Earth as well as of the WIMP-nucleus cross section. The only information about the nature of halo WIMPs which one needs is the WIMP mass. I also present a method for the determination of the WIMP mass by combining two (or more) experiments with different detector materials. This method is not only independent of the model of Galactic halo but also of that of WIMPs. (orig.)

  17. Theoretical interpretation of experimental data from direct dark matter detection

    International Nuclear Information System (INIS)

    Shan Chung-Lin

    2007-10-01

    I derive expressions that allow to reconstruct the normalized one-dimensional velocity distribution function of halo WIMPs and to determine its moments from the recoil energy spectrum as well as from experimental data directly. The reconstruction of the velocity distribution function is further extended to take into account the annual modulation of the event rate. All these expressions are independent of the as yet unknown WIMP density near the Earth as well as of the WIMP-nucleus cross section. The only information about the nature of halo WIMPs which one needs is the WIMP mass. I also present a method for the determination of the WIMP mass by combining two (or more) experiments with different detector materials. This method is not only independent of the model of Galactic halo but also of that of WIMPs. (orig.)

  18. Detecting Seismic Events Using a Supervised Hidden Markov Model

    Science.gov (United States)

    Burks, L.; Forrest, R.; Ray, J.; Young, C.

    2017-12-01

    We explore the use of supervised hidden Markov models (HMMs) to detect seismic events in streaming seismogram data. Current methods for seismic event detection include simple triggering algorithms, such as STA/LTA and the Z-statistic, which can lead to large numbers of false positives that must be investigated by an analyst. The hypothesis of this study is that more advanced detection methods, such as HMMs, may decreases false positives while maintaining accuracy similar to current methods. We train a binary HMM classifier using 2 weeks of 3-component waveform data from the International Monitoring System (IMS) that was carefully reviewed by an expert analyst to pick all seismic events. Using an ensemble of simple and discrete features, such as the triggering of STA/LTA, the HMM predicts the time at which transition occurs from noise to signal. Compared to the STA/LTA detection algorithm, the HMM detects more true events, but the false positive rate remains unacceptably high. Future work to potentially decrease the false positive rate may include using continuous features, a Gaussian HMM, and multi-class HMMs to distinguish between types of seismic waves (e.g., P-waves and S-waves). Acknowledgement: Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.SAND No: SAND2017-8154 A

  19. Polygraph lie detection on real events in a laboratory setting.

    Science.gov (United States)

    Bradley, M T; Cullen, M C

    1993-06-01

    This laboratory study dealt with real-life intense emotional events. Subjects generated embarrassing stories from their experience, then submitted to polygraph testing and, by lying, denied their stories and, by telling the truth, denied a randomly assigned story. Money was given as an incentive to be judged innocent on each story. An interrogator, blind to the stories, used Control Question Tests and found subjects more deceptive when lying than when truthful. Stories interacted with order such that lying on the second story was more easily detected than lying on the first. Embarrassing stories provide an alternative to the use of mock crimes to study lie detection in the laboratory.

  20. Cosmological radio emission induced by WIMP Dark Matter

    International Nuclear Information System (INIS)

    Fornengo, N.; Regis, M.; Lineros, R.; Taoso, M.

    2012-01-01

    We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs

  1. Cosmological radio emission induced by WIMP Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, N.; Regis, M. [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Lineros, R.; Taoso, M., E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: mtaoso@phas.ubc.ca [IFIC, CSIC-Universidad de Valencia, Ed. Institutos, Apdo. Correos 22085, E-46071 Valencia (Spain)

    2012-03-01

    We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs.

  2. Complexity of deciding detectability in discrete event systems

    Czech Academy of Sciences Publication Activity Database

    Masopust, Tomáš

    2018-01-01

    Roč. 93, July (2018), s. 257-261 ISSN 0005-1098 Institutional support: RVO:67985840 Keywords : discrete event systems * finite automata * detectability Subject RIV: BA - General Mathematics OBOR OECD: Computer science s, information science , bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 5.451, year: 2016 https://www. science direct.com/ science /article/pii/S0005109818301730

  3. Complexity of deciding detectability in discrete event systems

    Czech Academy of Sciences Publication Activity Database

    Masopust, Tomáš

    2018-01-01

    Roč. 93, July (2018), s. 257-261 ISSN 0005-1098 Institutional support: RVO:67985840 Keywords : discrete event systems * finite automata * detectability Subject RIV: BA - General Mathematics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 5.451, year: 2016 https://www.sciencedirect.com/science/article/pii/S0005109818301730

  4. Microseismic Events Detection on Xishancun Landslide, Sichuan Province, China

    Science.gov (United States)

    Sheng, M.; Chu, R.; Wei, Z.

    2016-12-01

    On landslide, the slope movement and the fracturing of the rock mass often lead to microearthquakes, which are recorded as weak signals on seismographs. The distribution characteristics of temporal and spatial regional unstability as well as the impact of external factors on the unstable regions can be understand and analyzed by monitoring those microseismic events. Microseismic method can provide some information inside the landslide, which can be used as supplementary of geodetic methods for monitoring the movement of landslide surface. Compared to drilling on landslide, microseismic method is more economical and safe. Xishancun Landslide is located about 60km northwest of Wenchuan earthquake centroid, it keep deforming after the earthquake, which greatly increases the probability of disasters. In the autumn of 2015, 30 seismometers were deployed on the landslide for 3 months with intervals of 200 500 meters. First, we used regional earthquakes for time correction of seismometers to eliminate the influence of inaccuracy GPS clocks and the subsurface structure of stations. Due to low velocity of the loose medium, the travel time difference of microseismic events on the landslide up to 5s. According to travel time and waveform characteristics, we found many microseismic events and converted them into envelopes as templates, then we used a sliding-window cross-correlation technique based on waveform envelope to detect the other microseismic events. Consequently, 100 microseismic events were detected with the waveforms recorded on all seismometers. Based on the location, we found most of them located on the front of the landslide while the others located on the back end. The bottom and top of the landslide accumulated considerable energy and deformed largely, radiated waves could be recorded by all stations. What's more, the bottom with more events seemed very active. In addition, there were many smaller events happened in middle part of the landslide where released

  5. Asymmetric WIMP Dark Matter in the presence of DM/anti-DM oscillations

    International Nuclear Information System (INIS)

    Zaharijas, G.

    2014-01-01

    The general class of 'Asymmetric Dark Matter (DM)' scenarios assumes the existence of a primordial particle/anti-particle asymmetry in the dark matter sector related to the asymmetry in the baryonic one, as a way to achieve the observed similarity between the baryonic and dark matter energy densities today. Focusing on this framework we study the effect of oscillations between dark matter and its anti-particle on the re-equilibration of the initial asymmetry. We calculate the evolution of the dark matter relic abundance and show how oscillations re-open the parameter space of asymmetric dark matter models, in particular in the direction of allowing large (WIMP-scale) DM masses. We found in particular that a typical WIMP with a mass at the EW scale (about 1 TeV) having a primordial asymmetry of the same order as the baryon asymmetry, naturally gets the correct relic abundance if the δm mass term is in the ∼ meV range. This turns out to be a natural value for fermionic DM arising from the higher dimensional operator H 2 DM 2 /Λ where H is the Higgs field and Λ ∼ M Pl . Finally, we constrain the parameter space in this framework by applying up-to-date bounds from indirect detection signals on annihilating DM

  6. Consequences of DM/antiDM Oscillations for Asymmetric WIMP Dark Matter

    CERN Document Server

    Cirelli, Marco; Servant, Geraldine; Zaharijas, Gabrijela

    2012-01-01

    Assuming the existence of a primordial asymmetry in the dark sector, a scenario usually dubbed Asymmetric Dark Matter (aDM), we study the effect of oscillations between dark matter and its antiparticle on the re-equilibration of the initial asymmetry before freeze-out, which enable efficient annihilations to recouple. We calculate the evolution of the DM relic abundance and show how oscillations re-open the parameter space of aDM models, in particular in the direction of allowing large (WIMP-scale) DM masses. A typical wimp with a mass at the EW scale (\\sim 100 GeV - 1 TeV) presenting a primordial asymmetry of the same order as the baryon asymmetry naturally gets the correct relic abundance if the DM-number-violating Delta(DM) = 2 mass term is in the \\sim meV range. The re-establishment of annihilations implies that constraints from the accumulation of aDM in astrophysical bodies are evaded. On the other hand, the ordinary bounds from BBN, CMB and indirect detection signals on annihilating DM have to be consi...

  7. Towards Optimal Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Agumbe Suresh, Mahima

    2012-01-03

    Acyclic flow networks, present in many infrastructures of national importance (e.g., oil & gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against these infrastructures, have been proven costly and imprecise, especially when dealing with large scale distribution systems. In this paper, to the best of our knowledge for the first time, we investigate how mobile sensor networks can be used for optimal event detection and localization in acyclic flow networks. Sensor nodes move along the edges of the network and detect events (i.e., attacks) and proximity to beacon nodes with known placement in the network. We formulate the problem of minimizing the cost of monitoring infrastructure (i.e., minimizing the number of sensor and beacon nodes deployed), while ensuring a degree of sensing coverage in a zone of interest and a required accuracy in locating events. We propose algorithms for solving these problems and demonstrate their effectiveness with results obtained from a high fidelity simulator.

  8. FOREWORD: 3rd Symposium on Large TPCs for Low Energy Event Detection

    Science.gov (United States)

    Irastorza, Igor G.; Colas, Paul; Gorodetzky, Phillippe

    2007-05-01

    The Third International Symposium on large TPCs for low-energy rare-event detection was held at Carré des sciences, Poincaré auditorium, 25 rue de la Montagne Ste Geneviève in Paris on 11 12 December 2006. This prestigious location belonging to the Ministry of Research is hosted in the former Ecole Polytechnique. The meeting, held in Paris every two years, gathers a significant community of physicists involved in rare event detection. Its purpose is an extensive discussion of present and future projects using large TPCs for low energy, low background detection of rare events (low-energy neutrinos, dark matter, solar axions). The use of a new generation of Micro-Pattern Gaseous Detectors (MPGD) appears to be a promising way to reach this goal. The program this year was enriched by a new session devoted to the detection challenge of polarized gamma rays, relevant novel experimental techniques and the impact on particle physics, astrophysics and astronomy. A very particular feature of this conference is the large variety of talks ranging from purely theoretical to purely experimental subjects including novel technological aspects. This allows discussion and exchange of useful information and new ideas that are emerging to address particle physics experimental challenges. The scientific highlights at the Symposium came on many fronts: Status of low-energy neutrino physics and double-beta decay New ideas on double-beta decay experiments Gamma ray polarization measurement combining high-precision TPCs with MPGD read-out Dark Matter challenges in both axion and WIMP search with new emerging ideas for detection improvements Progress in gaseous and liquid TPCs for rare event detection Georges Charpak opened the meeting with a talk on gaseous detectors for applications in the bio-medical field. He also underlined the importance of new MPGD detectors for both physics and applications. There were about 100 registered participants at the symposium. The successful

  9. Gaseous time projection chambers for rare event detection: results from the T-REX project. II. Dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Irastorza, I.G.; Aznar, F.; Castel, J., E-mail: igor.irastorza@cern.ch, E-mail: faznar@unizar.es, E-mail: jfcastel@unizar.es [Grupo de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C/ P. Cerbuna 12, Zaragoza, 50009 Spain (Spain); and others

    2016-01-01

    As part of the T-REX project, a number of R and D and prototyping activities have been carried out during the last years to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches like double beta decay, axion research and low-mass WIMP searches. While in the companion paper we focus on double beta decay, in this paper we focus on the results regarding the search for dark matter candidates, both axions and WIMPs. Small (few cm wide) ultra-low background Micromegas detectors are used to image the axion-induced x-ray signal expected in axion helioscopes like the CERN Axion Solar Telescope (CAST) experiment. Background levels as low as 0.8 × 10{sup −6} counts keV{sup −1} cm{sup −2} s{sup −1} have already been achieved in CAST while values down to ∼10{sup −7} counts keV{sup −1} cm{sup −2} s{sup −1} have been obtained in a test bench placed underground in the Laboratorio Subterráneo de Canfranc (LSC). Prospects to consolidate and further reduce these values down to ∼10{sup −8} counts keV{sup −1} cm{sup −2} s{sup −1} will be described. Such detectors, placed at the focal point of x-ray telescopes in the future International Axion Observatory (IAXO), would allow for 10{sup 5} better signal-to-noise ratio than CAST, and search for solar axions with g{sub a}γ down to few 10{sup 12} GeV{sup −1}, well into unexplored axion parameter space. In addition, a scaled-up version of these TPCs, properly shielded and placed underground, can be competitive in the search for low-mass WIMPs. The TREX-DM prototype, with ∼ 0.300 kg of Ar at 10 bar, or alternatively ∼ 0.160 kg of Ne at 10 bar, and energy threshold well below 1 keV, has been built to test this concept. We will describe the main technical solutions developed, as well as the results from the commissioning phase on surface. The anticipated sensitivity of this technique might reach ∼10{sup −44} cm{sup 2} for

  10. Machine learning for the automatic detection of anomalous events

    Science.gov (United States)

    Fisher, Wendy D.

    In this dissertation, we describe our research contributions for a novel approach to the application of machine learning for the automatic detection of anomalous events. We work in two different domains to ensure a robust data-driven workflow that could be generalized for monitoring other systems. Specifically, in our first domain, we begin with the identification of internal erosion events in earth dams and levees (EDLs) using geophysical data collected from sensors located on the surface of the levee. As EDLs across the globe reach the end of their design lives, effectively monitoring their structural integrity is of critical importance. The second domain of interest is related to mobile telecommunications, where we investigate a system for automatically detecting non-commercial base station routers (BSRs) operating in protected frequency space. The presence of non-commercial BSRs can disrupt the connectivity of end users, cause service issues for the commercial providers, and introduce significant security concerns. We provide our motivation, experimentation, and results from investigating a generalized novel data-driven workflow using several machine learning techniques. In Chapter 2, we present results from our performance study that uses popular unsupervised clustering algorithms to gain insights to our real-world problems, and evaluate our results using internal and external validation techniques. Using EDL passive seismic data from an experimental laboratory earth embankment, results consistently show a clear separation of events from non-events in four of the five clustering algorithms applied. Chapter 3 uses a multivariate Gaussian machine learning model to identify anomalies in our experimental data sets. For the EDL work, we used experimental data from two different laboratory earth embankments. Additionally, we explore five wavelet transform methods for signal denoising. The best performance is achieved with the Haar wavelets. We achieve up to 97

  11. Detection of red tide events in the Ariake Sound, Japan

    Science.gov (United States)

    Ishizaka, Joji

    2003-05-01

    High resolution SeaWiFS data was used to detect a red tide event occurred in the Ariake Sound, Japan, in winter of 2000 to 2001. The area is small embayment surrounding by tidal flat, and it is known as one of the most productive areas in coast of Japan. The red tide event damaged to seaweed (Nori) culture, and the relation to the reclamation at the Isahaya Bay in the Sound has been discussed. SeaWiFS chlorophyll data showed the red tide started early December 2000, from the Isahaya Bay, although direct relationship to the reclamation was not clear. The red tide persisted to the end of February. Monthly average of SeaWiFS data from May 1998 to December 2001 indicated that the chlorophyll increased twice a year, early summer and fall after the rain. The red tide event was part of the fall bloom which started later and continued longer than other years. Ocean color is useful to detect the red tide; however, it is required to improve the algorithms to accurately estimate chlorophyll in high turbid water and to discriminate toxic flagellates.

  12. Final results of the EDELWEISS-II WIMP search using a 4-kg array of cryogenic germanium detectors with interleaved electrodes

    International Nuclear Information System (INIS)

    Armengaud, E.; Augier, C.; Benoit, A.; Berge, L.; Bluemer, J.; Broniatowski, A.; Brudanin, V.; Censier, B.; Chardin, G.; Chapellier, M.; Charlieux, F.; Coulter, P.; Cox, G.A.; Defay, X.; De Jesus, M.; Dolgorouki, Y.; Domange, J.; Dumoulin, L.

    2011-01-01

    The EDELWEISS-II Collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of γ-induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4x10 -8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.

  13. 5th Patras workshop on axions, WIMPs and WISPs (PATRAS 2009). Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg; Lindner, Axel; Redondo, Javier [eds.

    2010-06-15

    The following topics were dealt with: Direct searches for dark matter, indirect searches for WIMPS, photon generation and laser polarization experiments, direct axion signals, theoretic WISP developments. (HSI)

  14. 5th Patras workshop on axions, WIMPs and WISPs (PATRAS 2009). Proceedings

    International Nuclear Information System (INIS)

    Jaeckel, Joerg; Lindner, Axel; Redondo, Javier

    2010-06-01

    The following topics were dealt with: Direct searches for dark matter, indirect searches for WIMPS, photon generation and laser polarization experiments, direct axion signals, theoretic WISP developments. (HSI)

  15. Search for WIMP dark matter produced in association with a Z boson with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00399337; The ATLAS collaboration

    2016-01-01

    The search for weakly interacting dark matter particle (WIMP) candidates produced in association with a Z boson with the ATLAS detector at the LHC is presented. Events with large missing transverse momentum and consistent with the decay of a Z boson into oppositely charged electron or muon pairs were selected in analysis. Background estimates and corresponding systematic uncertainties are shown. The limits on the mass scale of the contact interaction as a function of the dark matter particle mass and the limits on the coupling and scalar particle mediator mass for 8 TeV proton-proton collisions data are presented. Prospects for analysis using 13 TeV proton-proton collisions data are discussed.

  16. Piecing together the puzzle: Improving event content coverage for real-time sub-event detection using adaptive microblog crawling.

    Directory of Open Access Journals (Sweden)

    Laurissa Tokarchuk

    Full Text Available In an age when people are predisposed to report real-world events through their social media accounts, many researchers value the benefits of mining user generated content from social media. Compared with the traditional news media, social media services, such as Twitter, can provide more complete and timely information about the real-world events. However events are often like a puzzle and in order to solve the puzzle/understand the event, we must identify all the sub-events or pieces. Existing Twitter event monitoring systems for sub-event detection and summarization currently typically analyse events based on partial data as conventional data collection methodologies are unable to collect comprehensive event data. This results in existing systems often being unable to report sub-events in real-time and often in completely missing sub-events or pieces in the broader event puzzle. This paper proposes a Sub-event detection by real-TIme Microblog monitoring (STRIM framework that leverages the temporal feature of an expanded set of news-worthy event content. In order to more comprehensively and accurately identify sub-events this framework first proposes the use of adaptive microblog crawling. Our adaptive microblog crawler is capable of increasing the coverage of events while minimizing the amount of non-relevant content. We then propose a stream division methodology that can be accomplished in real time so that the temporal features of the expanded event streams can be analysed by a burst detection algorithm. In the final steps of the framework, the content features are extracted from each divided stream and recombined to provide a final summarization of the sub-events. The proposed framework is evaluated against traditional event detection using event recall and event precision metrics. Results show that improving the quality and coverage of event contents contribute to better event detection by identifying additional valid sub-events. The

  17. Piecing together the puzzle: Improving event content coverage for real-time sub-event detection using adaptive microblog crawling.

    Science.gov (United States)

    Tokarchuk, Laurissa; Wang, Xinyue; Poslad, Stefan

    2017-01-01

    In an age when people are predisposed to report real-world events through their social media accounts, many researchers value the benefits of mining user generated content from social media. Compared with the traditional news media, social media services, such as Twitter, can provide more complete and timely information about the real-world events. However events are often like a puzzle and in order to solve the puzzle/understand the event, we must identify all the sub-events or pieces. Existing Twitter event monitoring systems for sub-event detection and summarization currently typically analyse events based on partial data as conventional data collection methodologies are unable to collect comprehensive event data. This results in existing systems often being unable to report sub-events in real-time and often in completely missing sub-events or pieces in the broader event puzzle. This paper proposes a Sub-event detection by real-TIme Microblog monitoring (STRIM) framework that leverages the temporal feature of an expanded set of news-worthy event content. In order to more comprehensively and accurately identify sub-events this framework first proposes the use of adaptive microblog crawling. Our adaptive microblog crawler is capable of increasing the coverage of events while minimizing the amount of non-relevant content. We then propose a stream division methodology that can be accomplished in real time so that the temporal features of the expanded event streams can be analysed by a burst detection algorithm. In the final steps of the framework, the content features are extracted from each divided stream and recombined to provide a final summarization of the sub-events. The proposed framework is evaluated against traditional event detection using event recall and event precision metrics. Results show that improving the quality and coverage of event contents contribute to better event detection by identifying additional valid sub-events. The novel combination of

  18. Unsupervised behaviour-specific dictionary learning for abnormal event detection

    DEFF Research Database (Denmark)

    Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

    2015-01-01

    the training data is only a small proportion of the surveillance data. Therefore, we propose behavior-specific dictionaries (BSD) through unsupervised learning, pursuing atoms from the same type of behavior to represent one behavior dictionary. To further improve the dictionary by introducing information from...... potential infrequent normal patterns, we refine the dictionary by searching ‘missed atoms’ that have compact coefficients. Experimental results show that our BSD algorithm outperforms state-of-the-art dictionaries in abnormal event detection on the public UCSD dataset. Moreover, BSD has less false alarms...

  19. Peaked signals from dark matter velocity structures in direct detection experiments

    Science.gov (United States)

    Lang, Rafael F.; Weiner, Neal

    2010-06-01

    In direct dark matter detection experiments, conventional elastic scattering of WIMPs results in exponentially falling recoil spectra. In contrast, theories of WIMPs with excited states can lead to nuclear recoil spectra that peak at finite recoil energies ER. The peaks of such signals are typically fairly broad, with ΔER/Epeak ~ 1. We show that in the presence of dark matter structures with low velocity dispersion, such as streams or clumps, peaks from up-scattering can become extremely narrow with FWHM of a few keV only. This differs dramatically from the conventionally expected WIMP spectrum and would, once detected, open the possibility to measure the dark matter velocity structure with high accuracy. As an intriguing example, we confront the observed cluster of 3 events near 42 keV from the CRESST commissioning run with this scenario. Inelastic dark matter particles with a wide range of parameters are capable of producing such a narrow peak. We calculate the possible signals at other experiments, and find that such particles could also give rise to the signal at DAMA, although not from the same stream. Over some range of parameters, a signal would be visible at xenon experiments. We show that such dark matter peaks are a very clear signal and can be easily disentangled from potential backgrounds, both terrestrial or due to WIMP down-scattering, by an enhanced annual modulation in both the amplitude of the signal and its spectral shape.

  20. Peaked signals from dark matter velocity structures in direct detection experiments

    International Nuclear Information System (INIS)

    Lang, Rafael F.; Weiner, Neal

    2010-01-01

    In direct dark matter detection experiments, conventional elastic scattering of WIMPs results in exponentially falling recoil spectra. In contrast, theories of WIMPs with excited states can lead to nuclear recoil spectra that peak at finite recoil energies E R . The peaks of such signals are typically fairly broad, with ΔE R /E peak ∼ 1. We show that in the presence of dark matter structures with low velocity dispersion, such as streams or clumps, peaks from up-scattering can become extremely narrow with FWHM of a few keV only. This differs dramatically from the conventionally expected WIMP spectrum and would, once detected, open the possibility to measure the dark matter velocity structure with high accuracy. As an intriguing example, we confront the observed cluster of 3 events near 42 keV from the CRESST commissioning run with this scenario. Inelastic dark matter particles with a wide range of parameters are capable of producing such a narrow peak. We calculate the possible signals at other experiments, and find that such particles could also give rise to the signal at DAMA, although not from the same stream. Over some range of parameters, a signal would be visible at xenon experiments. We show that such dark matter peaks are a very clear signal and can be easily disentangled from potential backgrounds, both terrestrial or due to WIMP down-scattering, by an enhanced annual modulation in both the amplitude of the signal and its spectral shape

  1. How does structured sparsity work in abnormal event detection?

    DEFF Research Database (Denmark)

    Ren, Huamin; Pan, Hong; Olsen, Søren Ingvor

    the training, which is the due to the fact that abnormal videos are limited or even unavailable in advance in most video surveillance applications. As a result, there could be only one label in the training data which hampers supervised learning; 2) Even though there are multiple types of normal behaviors, how...... many normal patterns lie in the whole surveillance data is still unknown. This is because there is huge amount of video surveillance data and only a small proportion is used in algorithm learning, consequently, the normal patterns in the training data could be incomplete. As a result, any sparse...... structure learned from the training data could have a high bias and ruin the precision of abnormal event detection. Therefore, we in the paper propose an algorithm to solve the abnormality detection problem by sparse representation, in which local structured sparsity is preserved in coefficients. To better...

  2. Description and detection of burst events in turbulent flows

    Science.gov (United States)

    Schmid, P. J.; García-Gutierrez, A.; Jiménez, J.

    2018-04-01

    A mathematical and computational framework is developed for the detection and identification of coherent structures in turbulent wall-bounded shear flows. In a first step, this data-based technique will use an embedding methodology to formulate the fluid motion as a phase-space trajectory, from which state-transition probabilities can be computed. Within this formalism, a second step then applies repeated clustering and graph-community techniques to determine a hierarchy of coherent structures ranked by their persistencies. This latter information will be used to detect highly transitory states that act as precursors to violent and intermittent events in turbulent fluid motion (e.g., bursts). Used as an analysis tool, this technique allows the objective identification of intermittent (but important) events in turbulent fluid motion; however, it also lays the foundation for advanced control strategies for their manipulation. The techniques are applied to low-dimensional model equations for turbulent transport, such as the self-sustaining process (SSP), for varying levels of complexity.

  3. Efficient hemodynamic event detection utilizing relational databases and wavelet analysis

    Science.gov (United States)

    Saeed, M.; Mark, R. G.

    2001-01-01

    Development of a temporal query framework for time-oriented medical databases has hitherto been a challenging problem. We describe a novel method for the detection of hemodynamic events in multiparameter trends utilizing wavelet coefficients in a MySQL relational database. Storage of the wavelet coefficients allowed for a compact representation of the trends, and provided robust descriptors for the dynamics of the parameter time series. A data model was developed to allow for simplified queries along several dimensions and time scales. Of particular importance, the data model and wavelet framework allowed for queries to be processed with minimal table-join operations. A web-based search engine was developed to allow for user-defined queries. Typical queries required between 0.01 and 0.02 seconds, with at least two orders of magnitude improvement in speed over conventional queries. This powerful and innovative structure will facilitate research on large-scale time-oriented medical databases.

  4. Detecting and characterising ramp events in wind power time series

    International Nuclear Information System (INIS)

    Gallego, Cristóbal; Cuerva, Álvaro; Costa, Alexandre

    2014-01-01

    In order to implement accurate models for wind power ramp forecasting, ramps need to be previously characterised. This issue has been typically addressed by performing binary ramp/non-ramp classifications based on ad-hoc assessed thresholds. However, recent works question this approach. This paper presents the ramp function, an innovative wavelet- based tool which detects and characterises ramp events in wind power time series. The underlying idea is to assess a continuous index related to the ramp intensity at each time step, which is obtained by considering large power output gradients evaluated under different time scales (up to typical ramp durations). The ramp function overcomes some of the drawbacks shown by the aforementioned binary classification and permits forecasters to easily reveal specific features of the ramp behaviour observed at a wind farm. As an example, the daily profile of the ramp-up and ramp-down intensities are obtained for the case of a wind farm located in Spain

  5. Direct Dark Matter Detection through the use of a Xenon Based TPC Detector

    Science.gov (United States)

    Daniel, Jonathan; Akerib, Daniel; LZ group at SLAC

    2018-01-01

    The vast majority of matter in the universe is unaccounted for. Only 15% of the universe's mass density is visible matter, while the other 85% is Dark Matter (DM). The Weakly Interacting Massive Particle (WIMP) is currently the frontrunner of the DM candidates. The Large Underground Xenon (LUX) and next generation LUX-ZEPLIN (LZ) experiments are designed to directly detect WIMPs. Both experiments are xenon-based Time Projection Chambers (TPC) used to observe possible WIMP interactions. These interactions produce photons and electrons with the photons being collected in a set of two photomultiplier tube (PMT) arrays and the electrons drifted upwards in the detector by a strong electric field to create a secondary production of photons in gaseous xenon. These two populations of photons are classified as S1 and S2 signals, respectively. Using these signals we reconstruct the energy and position of the interaction and in doing so we can eliminate background events that would otherwise “light up” the detector. My participation in the experiment, while at SLAC, was the creation of the grids that produce the large electric field, along with additional lab activities aimed at testing the grids. While at Stan State, I work on background modeling in order to distinguish a possible WIMP signal from ambient backgrounds.

  6. An intermediate framework between WIMP, FIMP, and EWIP dark matter

    International Nuclear Information System (INIS)

    Yaguna, Carlos E.

    2012-01-01

    WIMP (Weakly Interacting Massive Particle), FIMP (Feebly interacting Massive Particle) and EWIP (Extremely Weakly Interacting Particle) dark matter are different theoretical frameworks that have been postulated to explain the dark matter. In this paper we examine an intermediate scenario that combines features from these three frameworks. It consists of a weakly interacting particle — à la WIMP — that does not reach thermal equilibrium in the early Universe — à la FIMP — and whose relic density is determined by the reheating temperature of the Universe — à la EWIP. As an example, an explicit realization of this framework, based on the singlet scalar model of dark matter, is analyzed in detail. In particular, the relic density is studied as a function of the parameters of the model, and the new viable region within this intermediate scenario is determined. Finally, it is shown that this alternative framework of dark matter allows for arbitrarily heavy dark matter particles and that it suggests a connection between dark matter and inflation

  7. Motion Pattern Extraction and Event Detection for Automatic Visual Surveillance

    Directory of Open Access Journals (Sweden)

    Benabbas Yassine

    2011-01-01

    Full Text Available Efficient analysis of human behavior in video surveillance scenes is a very challenging problem. Most traditional approaches fail when applied in real conditions and contexts like amounts of persons, appearance ambiguity, and occlusion. In this work, we propose to deal with this problem by modeling the global motion information obtained from optical flow vectors. The obtained direction and magnitude models learn the dominant motion orientations and magnitudes at each spatial location of the scene and are used to detect the major motion patterns. The applied region-based segmentation algorithm groups local blocks that share the same motion direction and speed and allows a subregion of the scene to appear in different patterns. The second part of the approach consists in the detection of events related to groups of people which are merge, split, walk, run, local dispersion, and evacuation by analyzing the instantaneous optical flow vectors and comparing the learned models. The approach is validated and experimented on standard datasets of the computer vision community. The qualitative and quantitative results are discussed.

  8. Balloon-Borne Infrasound Detection of Energetic Bolide Events

    Science.gov (United States)

    Young, Eliot F.; Ballard, Courtney; Klein, Viliam; Bowman, Daniel; Boslough, Mark

    2016-10-01

    Infrasound is usually defined as sound waves below 20 Hz, the nominal limit of human hearing. Infrasound waves propagate over vast distances through the Earth's atmosphere: the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization) has 48 installed infrasound-sensing stations around the world to detect nuclear detonations and other disturbances. In February 2013, several CTBTO infrasound stations detected infrasound signals from a large bolide that exploded over Chelyabinsk, Russia. Some stations recorded signals that had circumnavigated the Earth, over a day after the original event. The goal of this project is to improve upon the sensitivity of the CTBTO network by putting microphones on small, long-duration super-pressure balloons, with the overarching goal of studying the small end of the NEO population by using the Earth's atmosphere as a witness plate.A balloon-borne infrasound sensor is expected to have two advantages over ground-based stations: a lack of wind noise and a concentration of infrasound energy in the "stratospheric duct" between roughly 5 - 50 km altitude. To test these advantages, we have built a small balloon payload with five calibrated microphones. We plan to fly this payload on a NASA high-altitude balloon from Ft Sumner, NM in August 2016. We have arranged for three large explosions to take place in Socorro, NM while the balloon is aloft to assess the sensitivity of balloon-borne vs. ground-based infrasound sensors. We will report on the results from this test flight and the prospects for detecting/characterizing small bolides in the stratosphere.

  9. 7th Patras workshop on axions, WIMPs and WISPs (PATRAS 2011). Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zioutas, Konstantin; Schumann, Marc (eds.)

    2011-12-15

    The year 2011 was an exciting period to work on the ''dark side'' of the Universe. Several experimental claims of the direct detection of WIMP dark matter were challenged by the restrictive limits of several others. Dedicated experiments searching for axions, another well motivated dark matter candidate, and for axion-like particles continued to improve their limits and got an additional boost by puzzling astrophysical observations and new developments in theory. The LHC collected an unexpectedly large amount of data and started to produce results at an amazing speed. And finally, this year's Nobel price of physics was awarded to the observation of the accelerating expansion of the Universe, an effect which might be related to dark energy, whose nature remain among the biggest mysteries in physics. These exciting topics and many more important aspects of particle- and astroparticle physics were discussed between experimentalists and theorists at the 7th Patras Workshop on Axions, WIMPs, and WISPs. The workshop took place from June 27 - July 1, 2011, in the Royal Myconian and Myconian Imperial Resorts Hotels on the Greek island of Mykonos. As in the previous years, it was a very fruitful and lively meeting in an inspiring and open atmosphere, which allowed for many open and constructive discussions also on controversial topics. The scientific exchange, the beautiful scenery of the island, the venue itself, the food, an excursion to the ancient ruins of Delos, and finally an amazing conference dinner made this meeting really unique. The ''spirit'' of the workshop and its atmosphere cannot be brought to paper, but many of its scientific highlights are collected in these proceedings. We are looking forward to the 8th Patras Workshop, which will be held in Chicago (USA) July 18-22, 2012. It will be organized jointly by our US colleagues Andrei Afanasev (JLAB), Oliver Baker (Yale), and William Wester (FNAL).

  10. 7th Patras workshop on axions, WIMPs and WISPs (PATRAS 2011). Proceedings

    International Nuclear Information System (INIS)

    Zioutas, Konstantin; Schumann, Marc

    2011-12-01

    The year 2011 was an exciting period to work on the ''dark side'' of the Universe. Several experimental claims of the direct detection of WIMP dark matter were challenged by the restrictive limits of several others. Dedicated experiments searching for axions, another well motivated dark matter candidate, and for axion-like particles continued to improve their limits and got an additional boost by puzzling astrophysical observations and new developments in theory. The LHC collected an unexpectedly large amount of data and started to produce results at an amazing speed. And finally, this year's Nobel price of physics was awarded to the observation of the accelerating expansion of the Universe, an effect which might be related to dark energy, whose nature remain among the biggest mysteries in physics. These exciting topics and many more important aspects of particle- and astroparticle physics were discussed between experimentalists and theorists at the 7th Patras Workshop on Axions, WIMPs, and WISPs. The workshop took place from June 27 - July 1, 2011, in the Royal Myconian and Myconian Imperial Resorts Hotels on the Greek island of Mykonos. As in the previous years, it was a very fruitful and lively meeting in an inspiring and open atmosphere, which allowed for many open and constructive discussions also on controversial topics. The scientific exchange, the beautiful scenery of the island, the venue itself, the food, an excursion to the ancient ruins of Delos, and finally an amazing conference dinner made this meeting really unique. The ''spirit'' of the workshop and its atmosphere cannot be brought to paper, but many of its scientific highlights are collected in these proceedings. We are looking forward to the 8th Patras Workshop, which will be held in Chicago (USA) July 18-22, 2012. It will be organized jointly by our US colleagues Andrei Afanasev (JLAB), Oliver Baker (Yale), and William Wester (FNAL).

  11. DETECT: a MATLAB toolbox for event detection and identification in time series, with applications to artifact detection in EEG signals.

    Science.gov (United States)

    Lawhern, Vernon; Hairston, W David; Robbins, Kay

    2013-01-01

    Recent advances in sensor and recording technology have allowed scientists to acquire very large time-series datasets. Researchers often analyze these datasets in the context of events, which are intervals of time where the properties of the signal change relative to a baseline signal. We have developed DETECT, a MATLAB toolbox for detecting event time intervals in long, multi-channel time series. Our primary goal is to produce a toolbox that is simple for researchers to use, allowing them to quickly train a model on multiple classes of events, assess the accuracy of the model, and determine how closely the results agree with their own manual identification of events without requiring extensive programming knowledge or machine learning experience. As an illustration, we discuss application of the DETECT toolbox for detecting signal artifacts found in continuous multi-channel EEG recordings and show the functionality of the tools found in the toolbox. We also discuss the application of DETECT for identifying irregular heartbeat waveforms found in electrocardiogram (ECG) data as an additional illustration.

  12. DETECT: a MATLAB toolbox for event detection and identification in time series, with applications to artifact detection in EEG signals.

    Directory of Open Access Journals (Sweden)

    Vernon Lawhern

    Full Text Available Recent advances in sensor and recording technology have allowed scientists to acquire very large time-series datasets. Researchers often analyze these datasets in the context of events, which are intervals of time where the properties of the signal change relative to a baseline signal. We have developed DETECT, a MATLAB toolbox for detecting event time intervals in long, multi-channel time series. Our primary goal is to produce a toolbox that is simple for researchers to use, allowing them to quickly train a model on multiple classes of events, assess the accuracy of the model, and determine how closely the results agree with their own manual identification of events without requiring extensive programming knowledge or machine learning experience. As an illustration, we discuss application of the DETECT toolbox for detecting signal artifacts found in continuous multi-channel EEG recordings and show the functionality of the tools found in the toolbox. We also discuss the application of DETECT for identifying irregular heartbeat waveforms found in electrocardiogram (ECG data as an additional illustration.

  13. Thermalization time scales for WIMP capture by the Sun in effective theories

    Energy Technology Data Exchange (ETDEWEB)

    Widmark, A., E-mail: axel.widmark@fysik.su.se [The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova, SE-106 91 Stockholm (Sweden)

    2017-05-01

    I study the process of dark matter capture by the Sun, under the assumption of a Weakly Interacting Massive Particle (WIMP), in the framework of non-relativistic effective field theory. Hypothetically, WIMPs from the galactic halo can scatter against atomic nuclei in the solar interior, settle to thermal equilibrium with the solar core and annihilate to produce an observable flux of neutrinos. In particular, I examine the thermalization process using Monte-Carlo integration of WIMP trajectories. I consider WIMPs in a mass range of 10–1000 GeV and WIMP-nucleon interaction operators with different dependence on spin and transferred momentum. I find that the density profiles of captured WIMPs are in accordance with a thermal profile described by the Sun's gravitational potential and core temperature. Depending on the operator that governs the interaction, the majority of the thermalization time is spent in either the solar interior or exterior. If normalizing the WIMP-nuclei interaction strength to a specific capture rate, I find that the thermalization time differs at most by 3 orders of magnitude between operators. In most cases of interest, the thermalization time is many orders of magnitude shorter than the age of the solar system.

  14. Generalized spin-dependent WIMP-nucleus interactions and the DAMA modulation effect

    Energy Technology Data Exchange (ETDEWEB)

    Scopel, Stefano; Yoon, Kook-Hyun; Yoon, Jong-Hyun, E-mail: scopel@sogang.ac.kr, E-mail: koreasds@naver.com, E-mail: pledge200@gmail.com [Department of Physics, Sogang University, Seoul (Korea, Republic of)

    2015-07-01

    Guided by non-relativistic Effective Field Theory (EFT) we classify the most general spin-dependent interactions between a fermionic Weakly Interacting Massive Particle (WIMP) and nuclei, and within this class of models we discuss the viability of an interpretation of the DAMA modulation result in terms of a signal from WIMP elastic scatterings using a halo-independent approach. We find that, although several relativistic EFT's can lead to a spin-dependent cross section, in some cases with an explicit, non-negligible dependence on the WIMP incoming velocity, three main scenarios can be singled out in the non-relativistic limit which approximately encompass them all, and that only differ by their dependence on the transferred momentum. For two of them compatibility between DAMA and other constraints is possible for a WIMP mass below 30 GeV, but only for a WIMP velocity distribution in the halo of our Galaxy which departs from a Maxwellian. This is achieved by combining a suppression of the WIMP effective coupling to neutrons (to evade constraints from xenon and germanium detectors) to an explicit quadratic or quartic dependence of the cross section on the transferred momentum (that leads to a relative enhancement of the expected rate off sodium in DAMA compared to that off fluorine in droplet detectors and bubble chambers). For larger WIMP masses the same scenarios are excluded by scatterings off iodine in COUPP.

  15. Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter

    International Nuclear Information System (INIS)

    McDonald, John

    2012-01-01

    The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.

  16. Gravitationally induced particle production and its impact on the WIMP abundance

    Directory of Open Access Journals (Sweden)

    I. Baranov

    2015-12-01

    Full Text Available A large set of independent astronomical observations have provided a strong evidence for nonbaryonic dark matter in the Universe. One of the most investigated candidates is an unknown long-lived Weakly Interacting Massive Particle (WIMP which was in thermal equilibrium with the primeval plasma. Here we investigate the WIMP abundance based on the relativistic kinetic treatment for gravitationally induced particle production recently proposed in the literature (Lima and Baranov, 2014 [16]. The new evolution equation is deduced and solved both numerically and through a semi-analytical approach. The predictions of the WIMP observables are discussed and compared with the ones obtained in the standard approach.

  17. Optimal detection of burst events in gravitational wave interferometric observatories

    International Nuclear Information System (INIS)

    Vicere, Andrea

    2002-01-01

    We consider the problem of detecting a burst signal of unknown shape in the data from gravitational wave interferometric detectors. We introduce a statistic which generalizes the excess power statistic proposed first by Flanagan and Hughes, and then extended by Anderson et al. to the multiple detector case. The statistic that we propose is shown to be optimal for an arbitrary noise spectral characteristic, under the two hypotheses that the noise is Gaussian, albeit colored, and that the prior for the signal is uniform. The statistic derivation is based on the assumption that a signal affects only N parallel samples in the data stream, but that no other information is a priori available, and that the value of the signal at each sample can be arbitrary. This is the main difference from previous works, where different assumptions were made, such as a signal distribution uniform with respect to the metric induced by the (inverse) noise correlation matrix. The two choices are equivalent if the noise is white, and in that limit the two statistics do indeed coincide. In the general case, we believe that the statistic we propose may be more appropriate, because it does not reflect the characteristics of the noise affecting the detector on the supposed distribution of the gravitational wave signal. Moreover, we show that the proposed statistic can be easily implemented in its exact form, combining standard time-series analysis tools which can be efficiently implemented. We generalize this version of an excess power statistic to the multiple detector case, considering first a noise uncorrelated among the different instruments, and then including the effect of correlated noise. We discuss exact and approximate forms of the statistic; the choice depends on the characteristics of the noise and on the assumed length of the burst event. As an example, we show the sensitivity of the network of interferometers to a δ-function burst

  18. Developing Fluorescence Sensor Systems for Early Detection of Nitrification Events in Chloraminated Drinking Water Distribution Systems

    Science.gov (United States)

    Detection of nitrification events in chloraminated drinking water distribution systems remains an ongoing challenge for many drinking water utilities, including Dallas Water Utilities (DWU) and the City of Houston (CoH). Each year, these utilities experience nitrification events ...

  19. Dark matter spin determination with directional direct detection experiments

    Science.gov (United States)

    Catena, Riccardo; Conrad, Jan; Döring, Christian; Ferella, Alfredo Davide; Krauss, Martin B.

    2018-01-01

    If dark matter has spin 0, only two WIMP-nucleon interaction operators can arise as leading operators from the nonrelativistic reduction of renormalizable single-mediator models for dark matter-quark interactions. Based on this crucial observation, we show that about 100 signal events at next generation directional detection experiments can be enough to enable a 2 σ rejection of the spin 0 dark matter hypothesis in favor of alternative hypotheses where the dark matter particle has spin 1 /2 or 1. In this context, directional sensitivity is crucial since anisotropy patterns in the sphere of nuclear recoil directions depend on the spin of the dark matter particle. For comparison, about 100 signal events are expected in a CF4 detector operating at a pressure of 30 torr with an exposure of approximately 26,000 cubic-meter-detector days for WIMPs of 100 GeV mass and a WIMP-fluorine scattering cross section of 0.25 pb. Comparable exposures require an array of cubic meter time projection chamber detectors.

  20. SPEED : a semantics-based pipeline for economic event detection

    NARCIS (Netherlands)

    Hogenboom, F.P.; Hogenboom, A.C.; Frasincar, F.; Kaymak, U.; Meer, van der O.; Schouten, K.; Vandic, D.; Parsons, J.; Motoshi, S.; Shoval, P.; Woo, C.; Wand, Y.

    2010-01-01

    Nowadays, emerging news on economic events such as acquisitions has a substantial impact on the financial markets. Therefore, it is important to be able to automatically and accurately identify events in news items in a timely manner. For this, one has to be able to process a large amount of

  1. Automated Detection of Financial Events in News Text

    NARCIS (Netherlands)

    F.P. Hogenboom (Frederik)

    2014-01-01

    markdownabstractToday’s financial markets are inextricably linked with financial events like acquisitions, profit announcements, or product launches. Information extracted from news messages that report on such events could hence be beneficial for financial decision making. The ubiquity of news,

  2. Semantics-based information extraction for detecting economic events

    NARCIS (Netherlands)

    A.C. Hogenboom (Alexander); F. Frasincar (Flavius); K. Schouten (Kim); O. van der Meer

    2013-01-01

    textabstractAs today's financial markets are sensitive to breaking news on economic events, accurate and timely automatic identification of events in news items is crucial. Unstructured news items originating from many heterogeneous sources have to be mined in order to extract knowledge useful for

  3. Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure

    Science.gov (United States)

    Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fallon, S. R.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

    2017-06-01

    We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=1.6 ×10-41 cm2 (σp=5 ×10-40 cm2 ) at 35 GeV c-2 , almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

  4. Prescription-event monitoring: developments in signal detection.

    Science.gov (United States)

    Ferreira, Germano

    2007-01-01

    Prescription-event monitoring (PEM) is a non-interventional intensive method for post-marketing drug safety monitoring of newly licensed medicines. PEM studies are cohort studies where exposure is obtained from a centralised service and outcomes from simple questionnaires completed by general practitioners. Follow-up forms are sent for selected events. Because PEM captures all events and not only the suspected adverse drug reactions, PEM cohorts potentially differ in respect to the distribution of number of events per person depending on the nature of the drug under study. This variance can be related either with the condition for which the drug is prescribed (e.g. a condition causing high morbidity will have, in average, a higher number of events per person compared with a condition with lower morbidity) or with the drug effect itself. This paper describes an exploratory investigation of the distortion caused by product-related variations of the number of events to the interpretation of the proportional reporting ratio (PRR) values ("the higher the PRR, the greater the strength of the signal") computed using drug-cohort data. We studied this effect by assessing the agreement between the PRR based on events (event of interest vs all other events) and PRR based on cases (cases with the event of interest vs cases with any other events). PRR were calculated for all combinations reported to ten selected drugs against a comparator of 81 other drugs. Three of the ten drugs had a cohort with an apparent higher proportion of patients with lower number of events. The PRRs based on events were systematically higher than the PRR based on cases for the combinations reported to these three drugs. Additionally, when applying the threshold criteria for signal screening (n > or =3, PRR > or =1.5 and Chi-squared > or =4), the binary agreement was generally high but apparently lower for these three drugs. In conclusion, the distribution of events per patient in drug cohorts shall be

  5. Integrating physically based simulators with Event Detection Systems: Multi-site detection approach.

    Science.gov (United States)

    Housh, Mashor; Ohar, Ziv

    2017-03-01

    The Fault Detection (FD) Problem in control theory concerns of monitoring a system to identify when a fault has occurred. Two approaches can be distinguished for the FD: Signal processing based FD and Model-based FD. The former concerns of developing algorithms to directly infer faults from sensors' readings, while the latter uses a simulation model of the real-system to analyze the discrepancy between sensors' readings and expected values from the simulation model. Most contamination Event Detection Systems (EDSs) for water distribution systems have followed the signal processing based FD, which relies on analyzing the signals from monitoring stations independently of each other, rather than evaluating all stations simultaneously within an integrated network. In this study, we show that a model-based EDS which utilizes a physically based water quality and hydraulics simulation models, can outperform the signal processing based EDS. We also show that the model-based EDS can facilitate the development of a Multi-Site EDS (MSEDS), which analyzes the data from all the monitoring stations simultaneously within an integrated network. The advantage of the joint analysis in the MSEDS is expressed by increased detection accuracy (higher true positive alarms and fewer false alarms) and shorter detection time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Signal detection to identify serious adverse events (neuropsychiatric events in travelers taking mefloquine for chemoprophylaxis of malaria

    Directory of Open Access Journals (Sweden)

    Naing C

    2012-08-01

    Full Text Available Cho Naing,1,3 Kyan Aung,1 Syed Imran Ahmed,2 Joon Wah Mak31School of Medical Sciences, 2School of Pharmacy and Health Sciences, 3School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, MalaysiaBackground: For all medications, there is a trade-off between benefits and potential for harm. It is important for patient safety to detect drug-event combinations and analyze by appropriate statistical methods. Mefloquine is used as chemoprophylaxis for travelers going to regions with known chloroquine-resistant Plasmodium falciparum malaria. As such, there is a concern about serious adverse events associated with mefloquine chemoprophylaxis. The objective of the present study was to assess whether any signal would be detected for the serious adverse events of mefloquine, based on data in clinicoepidemiological studies.Materials and methods: We extracted data on adverse events related to mefloquine chemoprophylaxis from the two published datasets. Disproportionality reporting of adverse events such as neuropsychiatric events and other adverse events was presented in the 2 × 2 contingency table. Reporting odds ratio and corresponding 95% confidence interval [CI] data-mining algorithm was applied for the signal detection. The safety signals are considered significant when the ROR estimates and the lower limits of the corresponding 95% CI are ≥2.Results: Two datasets addressing adverse events of mefloquine chemoprophylaxis (one from a published article and one from a Cochrane systematic review were included for analyses. Reporting odds ratio 1.58, 95% CI: 1.49–1.68 based on published data in the selected article, and 1.195, 95% CI: 0.94–1.44 based on data in the selected Cochrane review. Overall, in both datasets, the reporting odds ratio values of lower 95% CI were less than 2.Conclusion: Based on available data, findings suggested that signals for serious adverse events pertinent to neuropsychiatric event were

  7. Network hydraulics inclusion in water quality event detection using multiple sensor stations data.

    Science.gov (United States)

    Oliker, Nurit; Ostfeld, Avi

    2015-09-01

    Event detection is one of the current most challenging topics in water distribution systems analysis: how regular on-line hydraulic (e.g., pressure, flow) and water quality (e.g., pH, residual chlorine, turbidity) measurements at different network locations can be efficiently utilized to detect water quality contamination events. This study describes an integrated event detection model which combines multiple sensor stations data with network hydraulics. To date event detection modelling is likely limited to single sensor station location and dataset. Single sensor station models are detached from network hydraulics insights and as a result might be significantly exposed to false positive alarms. This work is aimed at decreasing this limitation through integrating local and spatial hydraulic data understanding into an event detection model. The spatial analysis complements the local event detection effort through discovering events with lower signatures by exploring the sensors mutual hydraulic influences. The unique contribution of this study is in incorporating hydraulic simulation information into the overall event detection process of spatially distributed sensors. The methodology is demonstrated on two example applications using base runs and sensitivity analyses. Results show a clear advantage of the suggested model over single-sensor event detection schemes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Development of Ge/NbSi detectors for EDELWEISS-II with identification of near-surface events

    International Nuclear Information System (INIS)

    Juillard, A.; Marnieros, S.; Dolgorouky, Y.; Berge, L.; Collin, S.; Fiorucci, S.; Lalu, F.; Dumoulin, L.

    2006-01-01

    The actual limitation of Ge ionization heat cryogenic detectors for direct WIMP detection such as EDELWEISS arises from incomplete charge collection for near-surface events. We present results on Ge/NbSi detectors that are fitted with segmented electrodes and two NbSi Anderson insulator thermometric layers. Three such bolometers were studied in the low-background cryostat of the EDELWEISS collaboration in the LSM: analysis of the athermal signals allows us to identify and reject events occurring in the first millimeter under the electrodes

  9. Development of Ge/NbSi detectors for EDELWEISS-II with identification of near-surface events

    Energy Technology Data Exchange (ETDEWEB)

    Juillard, A. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France)]. E-mail: juillard@csnsm.in2p3.fr; Marnieros, S. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France); Dolgorouky, Y. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France); Berge, L. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France); Collin, S. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France); Fiorucci, S. [C.E.A, Centre d' etudes Nucleaires de Saclay, DSM/DAPNIA, Gif. Yvette, Cedex 91191n (France); Lalu, F. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France); Dumoulin, L. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), IN2P3/CNRS, Bat 108, Orsay Campus 91405 (France)

    2006-04-15

    The actual limitation of Ge ionization heat cryogenic detectors for direct WIMP detection such as EDELWEISS arises from incomplete charge collection for near-surface events. We present results on Ge/NbSi detectors that are fitted with segmented electrodes and two NbSi Anderson insulator thermometric layers. Three such bolometers were studied in the low-background cryostat of the EDELWEISS collaboration in the LSM: analysis of the athermal signals allows us to identify and reject events occurring in the first millimeter under the electrodes.

  10. Abnormal Event Detection in Wireless Sensor Networks Based on Multiattribute Correlation

    Directory of Open Access Journals (Sweden)

    Mengdi Wang

    2017-01-01

    Full Text Available Abnormal event detection is one of the vital tasks in wireless sensor networks. However, the faults of nodes and the poor deployment environment have brought great challenges to abnormal event detection. In a typical event detection technique, spatiotemporal correlations are collected to detect an event, which is susceptible to noises and errors. To improve the quality of detection results, we propose a novel approach for abnormal event detection in wireless sensor networks. This approach considers not only spatiotemporal correlations but also the correlations among observed attributes. A dependency model of observed attributes is constructed based on Bayesian network. In this model, the dependency structure of observed attributes is obtained by structure learning, and the conditional probability table of each node is calculated by parameter learning. We propose a new concept named attribute correlation confidence to evaluate the fitting degree between the sensor reading and the abnormal event pattern. On the basis of time correlation detection and space correlation detection, the abnormal events are identified. Experimental results show that the proposed algorithm can reduce the impact of interference factors and the rate of the false alarm effectively; it can also improve the accuracy of event detection.

  11. Multivariate algorithms for initiating event detection and identification in nuclear power plants

    International Nuclear Information System (INIS)

    Wu, Shun-Chi; Chen, Kuang-You; Lin, Ting-Han; Chou, Hwai-Pwu

    2018-01-01

    Highlights: •Multivariate algorithms for NPP initiating event detection and identification. •Recordings from multiple sensors are simultaneously considered for detection. •Both spatial and temporal information is used for event identification. •Untrained event isolation avoids falsely relating an untrained event. •Efficacy of the algorithms is verified with data from the Maanshan NPP simulator. -- Abstract: To prevent escalation of an initiating event into a severe accident, promptly detecting its occurrence and precisely identifying its type are essential. In this study, several multivariate algorithms for initiating event detection and identification are proposed to help maintain safe operations of nuclear power plants (NPPs). By monitoring changes in the NPP sensing variables, an event is detected when the preset thresholds are exceeded. Unlike existing approaches, recordings from sensors of the same type are simultaneously considered for detection, and no subjective reasoning is involved in setting these thresholds. To facilitate efficient event identification, a spatiotemporal feature extractor is proposed. The extracted features consist of the temporal traits used by existing techniques and the spatial signature of an event. Through an F-score-based feature ranking, only those that are most discriminant in classifying the events under consideration will be retained for identification. Moreover, an untrained event isolation scheme is introduced to avoid relating an untrained event to those in the event dataset so that improper recovery actions can be prevented. Results from experiments containing data of 12 event classes and a total of 125 events generated using a Taiwan’s Maanshan NPP simulator are provided to illustrate the efficacy of the proposed algorithms.

  12. arXiv Uncertainties in WIMP Dark Matter Scattering Revisited

    CERN Document Server

    Ellis, John; Olive, Keith A.

    We revisit the uncertainties in the calculation of spin-independent scattering matrix elements for the scattering of WIMP dark matter particles on nuclear matter. In addition to discussing the uncertainties due to limitations in our knowledge of the nucleonic matrix elements of the light quark scalar densities , we also discuss the importances of heavy quark scalar densities , and comment on uncertainties in quark mass ratios. We analyze estimates of the light-quark densities made over the past decade using lattice calculations and/or phenomenological inputs. We find an uncertainty in the combination that is larger than has been assumed in some phenomenological analyses, and a range of that is smaller but compatible with earlier estimates. We also analyze the importance of the {\\cal O}(\\alpha_s^3) calculations of the heavy-quark matrix elements that are now available, which provide an important refinement of the calculation of the spin-independent scattering cross section. We use for illustration a benchmar...

  13. Towards Optimal Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Agumbe Suresh, Mahima; Stoleru, Radu; Denton, Ron; Zechman, Emily; Shihada, Basem

    2012-01-01

    infrastructure (i.e., minimizing the number of sensor and beacon nodes deployed), while ensuring a degree of sensing coverage in a zone of interest and a required accuracy in locating events. We propose algorithms for solving these problems and demonstrate

  14. On the event detected by the Mont Blanc underground neutrino detector on February 23, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Dadykin, V L; Zatsepin, G T; Korchagin, V B

    1988-02-01

    The event detected by the Mont Balnc Soviet -Italian scintillation detector on February 23, 1987 at 2:52:37 are discussed. The corrected energies of the pulases of the event and the probability of the event imitation by the background are presented.

  15. The phenomenology of superWIMP dark matter scenariow with long-lived sleptons

    Energy Technology Data Exchange (ETDEWEB)

    Heisig, Jan

    2013-08-15

    We study the phenomenology of a supersymmetric scenario where the next-to-lightest superparticle (NLSP) is the charged slepton and is long-lived due to a lightest superparticle (LSP) which is a super weakly interacting massive particle (superWIMP), like the gravitino. This has far-reaching consequences for the cosmological history of the universe on the one hand and for the signatures at colliders on the other hand. We do not assume any high-scale model for the mediation of SUSY breaking to the MSSM but work along the lines of simplified models and the phenomenological MSSM (pMSSM). In a first part, we investigate the LHC sensitivity and its dependence on the superparticle spectrum with an emphasis on strong production and decay. We formulate appropriate simplified models that allow to conservatively approximate the signal efficiencies of arbitrary spectra from a small number of decisive parameters. We found that the application of simplified models is especially suitable in the considered scenario. Devising cuts that yield a large detection efficiency in the whole parameter space, we determine the discovery and exclusion potential of the LHC. We found that the prominent signature of long-lived sleptons allows to extract more robust constraints on the parameter space than for the widely studied case of a neutralino LSP scenario. In addition, we study the implications of the recent LHC results on the cosmological validity of a superWIMP Dark Matter scenario with a long-lived stau NLSP. Therefore, we work in a pMSSM framework and perform a Monte Carlo scan over the pMSSM parameter space highlighting the implications of a Higgs around 125 GeV and the nullsearches for heavy stable charged particles at the 7 and 8TeV LHC. Further, we consider bounds from MSSM Higgs searches, from flavor and precision observables as well as from the theoretical requirement of vacuum stability. In particular we work out the impact on the allowed range for the stau yield after freeze

  16. The phenomenology of superWIMP dark matter scenariow with long-lived sleptons

    International Nuclear Information System (INIS)

    Heisig, Jan

    2013-08-01

    We study the phenomenology of a supersymmetric scenario where the next-to-lightest superparticle (NLSP) is the charged slepton and is long-lived due to a lightest superparticle (LSP) which is a super weakly interacting massive particle (superWIMP), like the gravitino. This has far-reaching consequences for the cosmological history of the universe on the one hand and for the signatures at colliders on the other hand. We do not assume any high-scale model for the mediation of SUSY breaking to the MSSM but work along the lines of simplified models and the phenomenological MSSM (pMSSM). In a first part, we investigate the LHC sensitivity and its dependence on the superparticle spectrum with an emphasis on strong production and decay. We formulate appropriate simplified models that allow to conservatively approximate the signal efficiencies of arbitrary spectra from a small number of decisive parameters. We found that the application of simplified models is especially suitable in the considered scenario. Devising cuts that yield a large detection efficiency in the whole parameter space, we determine the discovery and exclusion potential of the LHC. We found that the prominent signature of long-lived sleptons allows to extract more robust constraints on the parameter space than for the widely studied case of a neutralino LSP scenario. In addition, we study the implications of the recent LHC results on the cosmological validity of a superWIMP Dark Matter scenario with a long-lived stau NLSP. Therefore, we work in a pMSSM framework and perform a Monte Carlo scan over the pMSSM parameter space highlighting the implications of a Higgs around 125 GeV and the nullsearches for heavy stable charged particles at the 7 and 8TeV LHC. Further, we consider bounds from MSSM Higgs searches, from flavor and precision observables as well as from the theoretical requirement of vacuum stability. In particular we work out the impact on the allowed range for the stau yield after freeze

  17. Indirect detection of dark matter

    International Nuclear Information System (INIS)

    Pieri, L.

    2008-01-01

    In the Cold Dark Matter scenario, the Dark Matter particle candidate may be a Weakly Interacting Massive Particle (Wimp). Annihilation of two Wimps in local or cosmological structures would result in the production of a number of standard model particles such as photons, leptons and baryons which could be observed with the presently available or future experiments such as the Pamela or Glast satellites or the Cherenkov Telescopes. In this work we review the status-of-the-art of the theoretical and phenomenological studies about the possibility of indirect detection of signals coming from Wimp annihilation.

  18. Dark Matter Detection: Current Status

    International Nuclear Information System (INIS)

    Akerib, Daniel S.

    2011-01-01

    Overwhelming observational evidence indicates that most of the matter in the Universe consists of non-baryonic dark matter. One possibility is that the dark matter is Weakly-Interacting Massive Particles (WIMPs) that were produced in the early Universe. These relics could comprise the Milky Way's dark halo and provide evidence for new particle physics, such as Supersymmetry. This talk focuses on the status of current efforts to detect dark matter by testing the hypothesis that WIMPs exist in the galactic halo. WIMP searches have begun to explore the region of parameter space where SUSY particles could provide dark matter candidates.

  19. A Dynamically Configurable Log-based Distributed Security Event Detection Methodology using Simple Event Correlator

    Science.gov (United States)

    2010-06-01

    Figures Figure Page 2.1. Verizon Data Breach Report: Detective Controls by percent of breach victims. [11...immature, operationally speaking. Figure 2.1: Verizon Data Breach Report: Detective Controls by percent of breach victims. [11] 7 The 2008 CSI Computer...Christopher Novak, Christopher Porter, Bryan Sartin, Peter Tippett, and J. Andrew Valentine. Data Breach Investigations Report. Technical report

  20. On Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Suresh, Mahima Agumbe; Stoleru, Radu; Zechman, Emily M.; Shihada, Basem

    2013-01-01

    Acyclic flow networks, present in many infrastructures of national importance (e.g., oil and gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against

  1. Unsupervised Event Characterization and Detection in Multichannel Signals: An EEG application

    Directory of Open Access Journals (Sweden)

    Angel Mur

    2016-04-01

    Full Text Available In this paper, we propose a new unsupervised method to automatically characterize and detect events in multichannel signals. This method is used to identify artifacts in electroencephalogram (EEG recordings of brain activity. The proposed algorithm has been evaluated and compared with a supervised method. To this end an example of the performance of the algorithm to detect artifacts is shown. The results show that although both methods obtain similar classification, the proposed method allows detecting events without training data and can also be applied in signals whose events are unknown a priori. Furthermore, the proposed method provides an optimal window whereby an optimal detection and characterization of events is found. The detection of events can be applied in real-time.

  2. Detection and location of multiple events by MARS. Final report

    International Nuclear Information System (INIS)

    Wang, J.; Masso, J.F.; Archambeau, C.B.; Savino, J.M.

    1980-09-01

    Seismic data from two explosions was processed using the Systems Science and Software MARS (Multiple Arrival Recognition System) seismic event detector in an effort to determine their relative spatial and temporal separation on the basis of seismic data alone. The explosions were less than 1.0 kilometer apart and were separated by less than 0.5 sec in origin times. The seismic data consisted of nine local accelerograms (r < 1.0 km) and four regional (240 through 400 km) seismograms. The MARS processing clearly indicates the presence of multiple explosions, but the restricted frequency range of the data inhibits accurate time picks and hence limits the precision of the event location

  3. Deep learning based beat event detection in action movie franchises

    Science.gov (United States)

    Ejaz, N.; Khan, U. A.; Martínez-del-Amor, M. A.; Sparenberg, H.

    2018-04-01

    Automatic understanding and interpretation of movies can be used in a variety of ways to semantically manage the massive volumes of movies data. "Action Movie Franchises" dataset is a collection of twenty Hollywood action movies from five famous franchises with ground truth annotations at shot and beat level of each movie. In this dataset, the annotations are provided for eleven semantic beat categories. In this work, we propose a deep learning based method to classify shots and beat-events on this dataset. The training dataset for each of the eleven beat categories is developed and then a Convolution Neural Network is trained. After finding the shot boundaries, key frames are extracted for each shot and then three classification labels are assigned to each key frame. The classification labels for each of the key frames in a particular shot are then used to assign a unique label to each shot. A simple sliding window based method is then used to group adjacent shots having the same label in order to find a particular beat event. The results of beat event classification are presented based on criteria of precision, recall, and F-measure. The results are compared with the existing technique and significant improvements are recorded.

  4. A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, R. [Max-Planck-Institut fuer Physik, Munich (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Angloher, G.; Ferreiro, N.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Reindl, F.; Seidel, W.; Stodolsky, L.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, CIUC, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Schaeffner, K. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Erb, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Feilitzsch, F. von; Guetlein, A.; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Roth, S.; Schoenert, S.; Stanger, M.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Jochum, J.; Loebell, J.; Rottler, K.; Sailer, C.; Scholl, S.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Kluck, H. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Vienna University of Technology, Atominstitut, Wien (Austria); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Schieck, J. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Sivers, M. von [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

    2015-08-15

    The cryogenic dark matter experiment CRESSTII aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO{sub 4} crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO{sub 4} sticks instead of metal clamps to hold the target crystal, a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ∝0.60 keV and a resolution of σ ∼ 0.090 keV (at 2.60 keV).With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3GeV/c{sup 2}. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail. (orig.)

  5. Falls event detection using triaxial accelerometry and barometric pressure measurement.

    Science.gov (United States)

    Bianchi, Federico; Redmond, Stephen J; Narayanan, Michael R; Cerutti, Sergio; Celler, Branko G; Lovell, Nigel H

    2009-01-01

    A falls detection system, employing a Bluetooth-based wearable device, containing a triaxial accelerometer and a barometric pressure sensor, is described. The aim of this study is to evaluate the use of barometric pressure measurement, as a surrogate measure of altitude, to augment previously reported accelerometry-based falls detection algorithms. The accelerometry and barometric pressure signals obtained from the waist-mounted device are analyzed by a signal processing and classification algorithm to discriminate falls from activities of daily living. This falls detection algorithm has been compared to two existing algorithms which utilize accelerometry signals alone. A set of laboratory-based simulated falls, along with other tasks associated with activities of daily living (16 tests) were performed by 15 healthy volunteers (9 male and 6 female; age: 23.7 +/- 2.9 years; height: 1.74 +/- 0.11 m). The algorithm incorporating pressure information detected falls with the highest sensitivity (97.8%) and the highest specificity (96.7%).

  6. Bidirectional RNN for Medical Event Detection in Electronic Health Records.

    Science.gov (United States)

    Jagannatha, Abhyuday N; Yu, Hong

    2016-06-01

    Sequence labeling for extraction of medical events and their attributes from unstructured text in Electronic Health Record (EHR) notes is a key step towards semantic understanding of EHRs. It has important applications in health informatics including pharmacovigilance and drug surveillance. The state of the art supervised machine learning models in this domain are based on Conditional Random Fields (CRFs) with features calculated from fixed context windows. In this application, we explored recurrent neural network frameworks and show that they significantly out-performed the CRF models.

  7. Power System Extreme Event Detection: The VulnerabilityFrontier

    Energy Technology Data Exchange (ETDEWEB)

    Lesieutre, Bernard C.; Pinar, Ali; Roy, Sandip

    2007-10-17

    In this work we apply graph theoretic tools to provide aclose bound on a frontier relating the number of line outages in a gridto the power disrupted by the outages. This frontier describes theboundary of a space relating the possible severity of a disturbance interms of power disruption, from zero to some maximum on the boundary, tothe number line outages involved in the event. We present the usefulnessof this analysis with a complete analysis of a 30 bus system, and presentresults for larger systems.

  8. Event detection in athletics for personalized sports content delivery

    DEFF Research Database (Denmark)

    Katsarakis, N.; Pnevmatikakis, A.

    2009-01-01

    Broadcasting of athletics is nowadays biased towards running (sprint and longer distances) sports. Personalized content delivery can change that for users that wish to focus on different content. Using a combination of video signal processing algorithms and live information that accompanies the v...... algorithms needed for the extraction of the events that trigger both between and within sport camera selection, and describes a system that handles user preferences, live information andvideo-generated events to offer personalized content to the users.......Broadcasting of athletics is nowadays biased towards running (sprint and longer distances) sports. Personalized content delivery can change that for users that wish to focus on different content. Using a combination of video signal processing algorithms and live information that accompanies...... the video of large-scale sports like the Olympics, a system can attend to the preferences of users by selecting the most suitable camera view for them.There are two types of camera selection for personalized content delivery. According to the between sport camera selection, the view is changed between two...

  9. Halo-independent determination of the unmodulated WIMP signal in DAMA: the isotropic case

    Energy Technology Data Exchange (ETDEWEB)

    Gondolo, Paolo [Department of Physics, University of Utah, 115 South 1400 East #201, Salt Lake City, Utah 84112-0830 (United States); Scopel, Stefano, E-mail: paolo.gondolo@utah.edu, E-mail: scopel@sogang.ac.kr [Department of Physics, Sogang University, Seoul 121-742 (Korea, Republic of)

    2017-09-01

    We present a halo-independent determination of the unmodulated signal corresponding to the DAMA modulation if interpreted as due to dark matter weakly interacting massive particles (WIMPs). First we show how a modulated signal gives information on the WIMP velocity distribution function in the Galactic rest frame from which the unmodulated signal descends. Then we describe a mathematically-sound profile likelihood analysis in which the likelihood is profiled over a continuum of nuisance parameters (namely, the WIMP velocity distribution). As a first application of the method, which is very general and valid for any class of velocity distributions, we restrict the analysis to velocity distributions that are isotropic in the Galactic frame. In this way we obtain halo-independent maximum-likelihood estimates and confidence intervals for the DAMA unmodulated signal. We find that the estimated unmodulated signal is in line with expectations for a WIMP-induced modulation and is compatible with the DAMA background+signal rate. Specifically, for the isotropic case we find that the modulated amplitude ranges between a few percent and about 25% of the unmodulated amplitude, depending on the WIMP mass.

  10. Study and optimization of bolometers designed to measure both ionization and heat in order to detect black matter

    International Nuclear Information System (INIS)

    Navick, X.F.

    1997-01-01

    The detection of black matter in the form of wimp (weakly interactive massive particle) requires the identification of the incident particle so that events due to wimp interactions can be set apart from events due to surrounding radioactivity. Bolometers allow to measure both the energy deposited and the ionization made by a particle. The amount of energy is determined by calorimetry. Wimp detection implies bolometers to run at very low temperature. After a presentation of particle interactions with matter, this thesis describes the physical phenomena involved in heat and ionization measurements. The behaviour of semiconductors at low temperature is investigated and qualitative expectations are drawn about the working of metal-semiconductor interface and the pin diode. An experimental setting is presented. The operating voltage needs to be very low in order to be the least disturbing possible. At so low voltage, a decrease of the ionization signal in terms of time appears. It is shown that this phenomenon is linked to the level density in the forbidden band of the semiconductor and to the intensity of infrared radiation reaching the detector. (A.C.)

  11. Spatial-temporal event detection in climate parameter imagery.

    Energy Technology Data Exchange (ETDEWEB)

    McKenna, Sean Andrew; Gutierrez, Karen A.

    2011-10-01

    Previously developed techniques that comprise statistical parametric mapping, with applications focused on human brain imaging, are examined and tested here for new applications in anomaly detection within remotely-sensed imagery. Two approaches to analysis are developed: online, regression-based anomaly detection and conditional differences. These approaches are applied to two example spatial-temporal data sets: data simulated with a Gaussian field deformation approach and weekly NDVI images derived from global satellite coverage. Results indicate that anomalies can be identified in spatial temporal data with the regression-based approach. Additionally, la Nina and el Nino climatic conditions are used as different stimuli applied to the earth and this comparison shows that el Nino conditions lead to significant decreases in NDVI in both the Amazon Basin and in Southern India.

  12. Full-waveform detection of non-impulsive seismic events based on time-reversal methods

    Science.gov (United States)

    Solano, Ericka Alinne; Hjörleifsdóttir, Vala; Liu, Qinya

    2017-12-01

    We present a full-waveform detection method for non-impulsive seismic events, based on time-reversal principles. We use the strain Green's tensor as a matched filter, correlating it with continuous observed seismograms, to detect non-impulsive seismic events. We show that this is mathematically equivalent to an adjoint method for detecting earthquakes. We define the detection function, a scalar valued function, which depends on the stacked correlations for a group of stations. Event detections are given by the times at which the amplitude of the detection function exceeds a given value relative to the noise level. The method can make use of the whole seismic waveform or any combination of time-windows with different filters. It is expected to have an advantage compared to traditional detection methods for events that do not produce energetic and impulsive P waves, for example glacial events, landslides, volcanic events and transform-fault earthquakes for events which velocity structure along the path is relatively well known. Furthermore, the method has advantages over empirical Greens functions template matching methods, as it does not depend on records from previously detected events, and therefore is not limited to events occurring in similar regions and with similar focal mechanisms as these events. The method is not specific to any particular way of calculating the synthetic seismograms, and therefore complicated structural models can be used. This is particularly beneficial for intermediate size events that are registered on regional networks, for which the effect of lateral structure on the waveforms can be significant. To demonstrate the feasibility of the method, we apply it to two different areas located along the mid-oceanic ridge system west of Mexico where non-impulsive events have been reported. The first study area is between Clipperton and Siqueiros transform faults (9°N), during the time of two earthquake swarms, occurring in March 2012 and May

  13. Detecting impacts of extreme events with ecological in situ monitoring networks

    Directory of Open Access Journals (Sweden)

    M. D. Mahecha

    2017-09-01

    Full Text Available Extreme hydrometeorological conditions typically impact ecophysiological processes on land. Satellite-based observations of the terrestrial biosphere provide an important reference for detecting and describing the spatiotemporal development of such events. However, in-depth investigations of ecological processes during extreme events require additional in situ observations. The question is whether the density of existing ecological in situ networks is sufficient for analysing the impact of extreme events, and what are expected event detection rates of ecological in situ networks of a given size. To assess these issues, we build a baseline of extreme reductions in the fraction of absorbed photosynthetically active radiation (FAPAR, identified by a new event detection method tailored to identify extremes of regional relevance. We then investigate the event detection success rates of hypothetical networks of varying sizes. Our results show that large extremes can be reliably detected with relatively small networks, but also reveal a linear decay of detection probabilities towards smaller extreme events in log–log space. For instance, networks with  ≈  100 randomly placed sites in Europe yield a  ≥  90 % chance of detecting the eight largest (typically very large extreme events; but only a  ≥  50 % chance of capturing the 39 largest events. These findings are consistent with probability-theoretic considerations, but the slopes of the decay rates deviate due to temporal autocorrelation and the exact implementation of the extreme event detection algorithm. Using the examples of AmeriFlux and NEON, we then investigate to what degree ecological in situ networks can capture extreme events of a given size. Consistent with our theoretical considerations, we find that today's systematically designed networks (i.e. NEON reliably detect the largest extremes, but that the extreme event detection rates are not higher than would

  14. Can tonne-scale direct detection experiments discover nuclear dark matter?

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M., E-mail: Alistair.Butcher.2010@live.rhul.ac.uk, E-mail: Russell.Kirk.2008@live.rhul.ac.uk, E-mail: Jocelyn.Monroe@rhul.ac.uk, E-mail: Stephen.West@rhul.ac.uk [Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX (United Kingdom)

    2017-10-01

    Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

  15. Can tonne-scale direct detection experiments discover nuclear dark matter?

    International Nuclear Information System (INIS)

    Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M.

    2017-01-01

    Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

  16. Prospects for SIMPLE 2000: a large-mass, low-background superheated droplet detector for WIMP searches

    International Nuclear Information System (INIS)

    Collar, J.I.; Girard, T.A.; Miley, H.S.; Waysand, G.

    2000-01-01

    The Superheated Instrument for Massive Particle searches (SIMPLE 2000) will consist of an array of 8-16 large active mass (approx. 15 g) superheated droplet detectors (SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make the use of SDDs an attractive approach for the detection of weakly interacting massive particles (WIMPs), namely their intrinsic insensitivity to minimally ionizing particles, high fluorine content, low cost and operation at near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from prototype SDDs for SIMPLE, as well as on the expected immediate increase in sensitivity of the programme, which aims at an exposure of > 25 kg day during 2000. The ability of modest-mass fluorine-rich detectors to investigate regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out. (author)

  17. Prospects for SIMPLE 2000: a large-mass, low-background superheated droplet detector for WIMP searches

    International Nuclear Information System (INIS)

    Collar, J I; Puibasset, J; Girard, T A; Limagne, D; Miley, H S; Waysand, G

    2000-01-01

    The Superheated Instrument for Massive Particle searches (SIMPLE 2000) will consist of an array of 8-16 large active mass (≅15 g) superheated droplet detectors (SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make the use of SDDs an attractive approach for the detection of weakly interacting massive particles (WIMPs), namely their intrinsic insensitivity to minimally ionizing particles, high fluorine content, low cost and operation at near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from prototype SDDs for SIMPLE, as well as on the expected immediate increase in sensitivity of the programme, which aims at an exposure of > 25 kg day during 2000. The ability of modest-mass fluorine-rich detectors to investigate regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out

  18. A coupled classification - evolutionary optimization model for contamination event detection in water distribution systems.

    Science.gov (United States)

    Oliker, Nurit; Ostfeld, Avi

    2014-03-15

    This study describes a decision support system, alerts for contamination events in water distribution systems. The developed model comprises a weighted support vector machine (SVM) for the detection of outliers, and a following sequence analysis for the classification of contamination events. The contribution of this study is an improvement of contamination events detection ability and a multi-dimensional analysis of the data, differing from the parallel one-dimensional analysis conducted so far. The multivariate analysis examines the relationships between water quality parameters and detects changes in their mutual patterns. The weights of the SVM model accomplish two goals: blurring the difference between sizes of the two classes' data sets (as there are much more normal/regular than event time measurements), and adhering the time factor attribute by a time decay coefficient, ascribing higher importance to recent observations when classifying a time step measurement. All model parameters were determined by data driven optimization so the calibration of the model was completely autonomic. The model was trained and tested on a real water distribution system (WDS) data set with randomly simulated events superimposed on the original measurements. The model is prominent in its ability to detect events that were only partly expressed in the data (i.e., affecting only some of the measured parameters). The model showed high accuracy and better detection ability as compared to previous modeling attempts of contamination event detection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Object-Oriented Query Language For Events Detection From Images Sequences

    Science.gov (United States)

    Ganea, Ion Eugen

    2015-09-01

    In this paper is presented a method to represent the events extracted from images sequences and the query language used for events detection. Using an object oriented model the spatial and temporal relationships between salient objects and also between events are stored and queried. This works aims to unify the storing and querying phases for video events processing. The object oriented language syntax used for events processing allow the instantiation of the indexes classes in order to improve the accuracy of the query results. The experiments were performed on images sequences provided from sport domain and it shows the reliability and the robustness of the proposed language. To extend the language will be added a specific syntax for constructing the templates for abnormal events and for detection of the incidents as the final goal of the research.

  20. Discrete Event Simulation Model of the Polaris 2.1 Gamma Ray Imaging Radiation Detection Device

    Science.gov (United States)

    2016-06-01

    release; distribution is unlimited DISCRETE EVENT SIMULATION MODEL OF THE POLARIS 2.1 GAMMA RAY IMAGING RADIATION DETECTION DEVICE by Andres T...ONLY (Leave blank) 2. REPORT DATE June 2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE DISCRETE EVENT SIMULATION MODEL...modeled. The platform, Simkit, was utilized to create a discrete event simulation (DES) model of the Polaris. After carefully constructing the DES

  1. Event Detection Challenges, Methods, and Applications in Natural and Artificial Systems

    Science.gov (United States)

    2009-03-01

    Sauvageon, Agogino, Mehr, and Tumer [2006], for instance, use a fourth degree polynomial within an event detection algorithm to sense high... cancer , and coronary artery disease. His study examines the age at which to begin screening exams, the intervals between the exams, and (possibly...AM, Mehr AF, and Tumer IY. 2006. “Comparison of Event Detection Methods for Centralized Sensor Networks.” IEEE Sensors Applications Symposium 2006

  2. Screening DNA chip and event-specific multiplex PCR detection methods for biotech crops.

    Science.gov (United States)

    Lee, Seong-Hun

    2014-11-01

    There are about 80 biotech crop events that have been approved by safety assessment in Korea. They have been controlled by genetically modified organism (GMO) and living modified organism (LMO) labeling systems. The DNA-based detection method has been used as an efficient scientific management tool. Recently, the multiplex polymerase chain reaction (PCR) and DNA chip have been developed as simultaneous detection methods for several biotech crops' events. The event-specific multiplex PCR method was developed to detect five biotech maize events: MIR604, Event 3272, LY 038, MON 88017 and DAS-59122-7. The specificity was confirmed and the sensitivity was 0.5%. The screening DNA chip was developed from four endogenous genes of soybean, maize, cotton and canola respectively along with two regulatory elements and seven genes: P35S, tNOS, pat, bar, epsps1, epsps2, pmi, cry1Ac and cry3B. The specificity was confirmed and the sensitivity was 0.5% for four crops' 12 events: one soybean, six maize, three cotton and two canola events. The multiplex PCR and DNA chip can be available for screening, gene-specific and event-specific analysis of biotech crops as efficient detection methods by saving on workload and time. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

  3. An integrated logit model for contamination event detection in water distribution systems.

    Science.gov (United States)

    Housh, Mashor; Ostfeld, Avi

    2015-05-15

    The problem of contamination event detection in water distribution systems has become one of the most challenging research topics in water distribution systems analysis. Current attempts for event detection utilize a variety of approaches including statistical, heuristics, machine learning, and optimization methods. Several existing event detection systems share a common feature in which alarms are obtained separately for each of the water quality indicators. Unifying those single alarms from different indicators is usually performed by means of simple heuristics. A salient feature of the current developed approach is using a statistically oriented model for discrete choice prediction which is estimated using the maximum likelihood method for integrating the single alarms. The discrete choice model is jointly calibrated with other components of the event detection system framework in a training data set using genetic algorithms. The fusing process of each indicator probabilities, which is left out of focus in many existing event detection system models, is confirmed to be a crucial part of the system which could be modelled by exploiting a discrete choice model for improving its performance. The developed methodology is tested on real water quality data, showing improved performances in decreasing the number of false positive alarms and in its ability to detect events with higher probabilities, compared to previous studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Energy-Efficient Fault-Tolerant Dynamic Event Region Detection in Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Enemark, Hans-Jacob; Zhang, Yue; Dragoni, Nicola

    2015-01-01

    to a hybrid algorithm for dynamic event region detection, such as real-time tracking of chemical leakage regions. Considering the characteristics of the moving away dynamic events, we propose a return back condition for the hybrid algorithm from distributed neighborhood collaboration, in which a node makes......Fault-tolerant event detection is fundamental to wireless sensor network applications. Existing approaches usually adopt neighborhood collaboration for better detection accuracy, while need more energy consumption due to communication. Focusing on energy efficiency, this paper makes an improvement...... its detection decision based on decisions received from its spatial and temporal neighbors, to local non-communicative decision making. The simulation results demonstrate that the improved algorithm does not degrade the detection accuracy of the original algorithm, while it has better energy...

  5. Adaptive Sensor Tuning for Seismic Event Detection in Environment with Electromagnetic Noise

    Science.gov (United States)

    Ziegler, Abra E.

    The goal of this research is to detect possible microseismic events at a carbon sequestration site. Data recorded on a continuous downhole microseismic array in the Farnsworth Field, an oil field in Northern Texas that hosts an ongoing carbon capture, utilization, and storage project, were evaluated using machine learning and reinforcement learning techniques to determine their effectiveness at seismic event detection on a dataset with electromagnetic noise. The data were recorded from a passive vertical monitoring array consisting of 16 levels of 3-component 15 Hz geophones installed in the field and continuously recording since January 2014. Electromagnetic and other noise recorded on the array has significantly impacted the utility of the data and it was necessary to characterize and filter the noise in order to attempt event detection. Traditional detection methods using short-term average/long-term average (STA/LTA) algorithms were evaluated and determined to be ineffective because of changing noise levels. To improve the performance of event detection and automatically and dynamically detect seismic events using effective data processing parameters, an adaptive sensor tuning (AST) algorithm developed by Sandia National Laboratories was utilized. AST exploits neuro-dynamic programming (reinforcement learning) trained with historic event data to automatically self-tune and determine optimal detection parameter settings. The key metric that guides the AST algorithm is consistency of each sensor with its nearest neighbors: parameters are automatically adjusted on a per station basis to be more or less sensitive to produce consistent agreement of detections in its neighborhood. The effects that changes in neighborhood configuration have on signal detection were explored, as it was determined that neighborhood-based detections significantly reduce the number of both missed and false detections in ground-truthed data. The performance of the AST algorithm was

  6. Automatic Detection and Classification of Audio Events for Road Surveillance Applications

    Directory of Open Access Journals (Sweden)

    Noor Almaadeed

    2018-06-01

    Full Text Available This work investigates the problem of detecting hazardous events on roads by designing an audio surveillance system that automatically detects perilous situations such as car crashes and tire skidding. In recent years, research has shown several visual surveillance systems that have been proposed for road monitoring to detect accidents with an aim to improve safety procedures in emergency cases. However, the visual information alone cannot detect certain events such as car crashes and tire skidding, especially under adverse and visually cluttered weather conditions such as snowfall, rain, and fog. Consequently, the incorporation of microphones and audio event detectors based on audio processing can significantly enhance the detection accuracy of such surveillance systems. This paper proposes to combine time-domain, frequency-domain, and joint time-frequency features extracted from a class of quadratic time-frequency distributions (QTFDs to detect events on roads through audio analysis and processing. Experiments were carried out using a publicly available dataset. The experimental results conform the effectiveness of the proposed approach for detecting hazardous events on roads as demonstrated by 7% improvement of accuracy rate when compared against methods that use individual temporal and spectral features.

  7. Event-specific qualitative and quantitative detection of five genetically modified rice events using a single standard reference molecule.

    Science.gov (United States)

    Kim, Jae-Hwan; Park, Saet-Byul; Roh, Hyo-Jeong; Shin, Min-Ki; Moon, Gui-Im; Hong, Jin-Hwan; Kim, Hae-Yeong

    2017-07-01

    One novel standard reference plasmid, namely pUC-RICE5, was constructed as a positive control and calibrator for event-specific qualitative and quantitative detection of genetically modified (GM) rice (Bt63, Kemingdao1, Kefeng6, Kefeng8, and LLRice62). pUC-RICE5 contained fragments of a rice-specific endogenous reference gene (sucrose phosphate synthase) as well as the five GM rice events. An existing qualitative PCR assay approach was modified using pUC-RICE5 to create a quantitative method with limits of detection correlating to approximately 1-10 copies of rice haploid genomes. In this quantitative PCR assay, the square regression coefficients ranged from 0.993 to 1.000. The standard deviation and relative standard deviation values for repeatability ranged from 0.02 to 0.22 and 0.10% to 0.67%, respectively. The Ministry of Food and Drug Safety (Korea) validated the method and the results suggest it could be used routinely to identify five GM rice events. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Impact of sensor detection limits on protecting water distribution systems from contamination events

    International Nuclear Information System (INIS)

    McKenna, Sean Andrew; Hart, David Blaine; Yarrington, Lane

    2006-01-01

    Real-time water quality sensors are becoming commonplace in water distribution systems. However, field deployable, contaminant-specific sensors are still in the development stage. As development proceeds, the necessary operating parameters of these sensors must be determined to protect consumers from accidental and malevolent contamination events. This objective can be quantified in several different ways including minimization of: the time necessary to detect a contamination event, the population exposed to contaminated water, the extent of the contamination within the network, and others. We examine the ability of a sensor set to meet these objectives as a function of both the detection limit of the sensors and the number of sensors in the network. A moderately sized distribution network is used as an example and different sized sets of randomly placed sensors are considered. For each combination of a certain number of sensors and a detection limit, the mean values of the different objectives across multiple random sensor placements are calculated. The tradeoff between the necessary detection limit in a sensor and the number of sensors is evaluated. Results show that for the example problem examined here, a sensor detection limit of 0.01 of the average source concentration is adequate for maximum protection. Detection of events is dependent on the detection limit of the sensors, but for those events that are detected, the values of the performance measures are not a function of the sensor detection limit. The results of replacing a single sensor in a network with a sensor having a much lower detection limit show that while this replacement can improve results, the majority of the additional events detected had performance measures of relatively low consequence.

  9. Insertable cardiac event recorder in detection of atrial fibrillation after cryptogenic stroke: an audit report.

    Science.gov (United States)

    Etgen, Thorleif; Hochreiter, Manfred; Mundel, Markus; Freudenberger, Thomas

    2013-07-01

    Atrial fibrillation (AF) is the most frequent risk factor in ischemic stroke but often remains undetected. We analyzed the value of insertable cardiac event recorder in detection of AF in a 1-year cohort of patients with cryptogenic ischemic stroke. All patients with cryptogenic stroke and eligibility for oral anticoagulation were offered the insertion of a cardiac event recorder. Regular follow-up for 1 year recorded the incidence of AF. Of the 393 patients with ischemic stroke, 65 (16.5%) had a cryptogenic stroke, and in 22 eligible patients, an event recorder was inserted. After 1 year, in 6 of 22 patients (27.3%), AF was detected. These preliminary data show that insertion of cardiac event recorder was eligible in approximately one third of patients with cryptogenic stroke and detected in approximately one quarter of these patients new AF.

  10. A robust neural network-based approach for microseismic event detection

    KAUST Repository

    Akram, Jubran

    2017-08-17

    We present an artificial neural network based approach for robust event detection from low S/N waveforms. We use a feed-forward network with a single hidden layer that is tuned on a training dataset and later applied on the entire example dataset for event detection. The input features used include the average of absolute amplitudes, variance, energy-ratio and polarization rectilinearity. These features are calculated in a moving-window of same length for the entire waveform. The output is set as a user-specified relative probability curve, which provides a robust way of distinguishing between weak and strong events. An optimal network is selected by studying the weight-based saliency and effect of number of neurons on the predicted results. Using synthetic data examples, we demonstrate that this approach is effective in detecting weaker events and reduces the number of false positives.

  11. Real-time detection and classification of anomalous events in streaming data

    Science.gov (United States)

    Ferragut, Erik M.; Goodall, John R.; Iannacone, Michael D.; Laska, Jason A.; Harrison, Lane T.

    2016-04-19

    A system is described for receiving a stream of events and scoring the events based on anomalousness and maliciousness (or other classification). The events can be displayed to a user in user-defined groupings in an animated fashion. The system can include a plurality of anomaly detectors that together implement an algorithm to identify low probability events and detect atypical traffic patterns. The atypical traffic patterns can then be classified as being of interest or not. In one particular example, in a network environment, the classification can be whether the network traffic is malicious or not.

  12. Early snowmelt events: detection, distribution, and significance in a major sub-arctic watershed

    International Nuclear Information System (INIS)

    Semmens, Kathryn Alese; Ramage, Joan; Bartsch, Annett; Liston, Glen E

    2013-01-01

    High latitude drainage basins are experiencing higher average temperatures, earlier snowmelt onset in spring, and an increase in rain on snow (ROS) events in winter, trends that climate models project into the future. Snowmelt-dominated basins are most sensitive to winter temperature increases that influence the frequency of ROS events and the timing and duration of snowmelt, resulting in changes to spring runoff. Of specific interest in this study are early melt events that occur in late winter preceding melt onset in the spring. The study focuses on satellite determination and characterization of these early melt events using the Yukon River Basin (Canada/USA) as a test domain. The timing of these events was estimated using data from passive (Advanced Microwave Scanning Radiometer—EOS (AMSR-E)) and active (SeaWinds on Quick Scatterometer (QuikSCAT)) microwave remote sensors, employing detection algorithms for brightness temperature (AMSR-E) and radar backscatter (QuikSCAT). The satellite detected events were validated with ground station meteorological and hydrological data, and the spatial and temporal variability of the events across the entire river basin was characterized. Possible causative factors for the detected events, including ROS, fog, and positive air temperatures, were determined by comparing the timing of the events to parameters from SnowModel and National Centers for Environmental Prediction North American Regional Reanalysis (NARR) outputs, and weather station data. All melt events coincided with above freezing temperatures, while a limited number corresponded to ROS (determined from SnowModel and ground data) and a majority to fog occurrence (determined from NARR). The results underscore the significant influence that warm air intrusions have on melt in some areas and demonstrate the large temporal and spatial variability over years and regions. The study provides a method for melt detection and a baseline from which to assess future change

  13. Impacts of WIMP dark matter upon stellar evolution: main-sequence stars

    CERN Document Server

    Scott, Pat; Edsjo, Joakim

    2008-01-01

    The presence of large amounts of WIMP dark matter in stellar cores has been shown to have significant effects upon models of stellar evolution. We present a series of detailed grids of WIMP-influenced stellar models for main sequence stars, computed using the DarkStars code. We describe the changes in stellar structure and main sequence evolution which occur for masses ranging from 0.3 to 2.0 solar masses and metallicities from Z = 0.0003-0.02, as a function of the rate of energy injection by WIMPs. We then go on to show what rates of energy injection can be obtained using realistic orbital parameters for stars near supermassive black holes, including detailed considerations of dark matter halo velocity and density profiles. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits, causing WIMP annihilation to provide up to 100 times the energy of hydrogen fusion in stars at the Galactic centre.

  14. Simultaneous generation of WIMP miracle-like densities of baryons and dark matter

    International Nuclear Information System (INIS)

    McDonald, John

    2011-01-01

    The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Dark matter is due to O(100) GeV gauge singlet scalars produced in the annihilation of the O(TeV) colored scalars which are responsible for the final thermal WIMP-like baryon asymmetry. The requirement of no baryon washout implies that there are two gauge singlet scalars. The low-temperature transfer of the asymmetry to conventional baryons can be understood if the long-lived O(TeV) colored scalars have large hypercharge, |Y|>4/3. Production of such scalars at the LHC would be a clear signature of the model.

  15. Ultra-cold WIMPs relics of non-standard pre-BBN cosmologies

    CERN Document Server

    Gelmini, Graciela B

    2008-01-01

    We point out that in scenarios in which the Universe evolves in a non-standard manner during and after the kinetic decoupling of weakly interacting massive particles (WIMPs), these relics can be much colder than in standard cosmological scenarios (i.e. can be ultra-cold), possibly leading to the formation of smaller first objects in hierarchical structure formation scenarios.

  16. Development of Time Projection Chambers with Micromegas for Rare Event Searches

    CERN Document Server

    Tomas, Alfredo; Villar, J A

    The Rare Event Searches is a heterogeneous field from the point of view of their physical motivations: double betha neutrinoless decay experiments, direct detection of WIMPs as well as axions and other WISPs (candidates for the DM, but also motivated by other questions from Particle Physics). The field is rather defined by the requirements of these experiments, essentially a very sensitive detector with low background which is usually operated in underground laboratories. The availability of a rich description of the event registered by the detector is a powerful tool for the discrimination of the signal from the background. The topological description of the interaction that can be delivered by a gaseous TPC is a useful source of information about the event. The generic requirements for a gaseous TPC that is intended for rare event searches are very good imaging capabilities, high gain and efficiency, stability and reliability and radio-purity, which could imply working with particular gases, in absence of q...

  17. Contamination Event Detection with Multivariate Time-Series Data in Agricultural Water Monitoring

    Directory of Open Access Journals (Sweden)

    Yingchi Mao

    2017-12-01

    Full Text Available Time series data of multiple water quality parameters are obtained from the water sensor networks deployed in the agricultural water supply network. The accurate and efficient detection and warning of contamination events to prevent pollution from spreading is one of the most important issues when pollution occurs. In order to comprehensively reduce the event detection deviation, a spatial–temporal-based event detection approach with multivariate time-series data for water quality monitoring (M-STED was proposed. The M-STED approach includes three parts. The first part is that M-STED adopts a Rule K algorithm to select backbone nodes as the nodes in the CDS, and forward the sensed data of multiple water parameters. The second part is to determine the state of each backbone node with back propagation neural network models and the sequential Bayesian analysis in the current timestamp. The third part is to establish a spatial model with Bayesian networks to estimate the state of the backbones in the next timestamp and trace the “outlier” node to its neighborhoods to detect a contamination event. The experimental results indicate that the average detection rate is more than 80% with M-STED and the false detection rate is lower than 9%, respectively. The M-STED approach can improve the rate of detection by about 40% and reduce the false alarm rate by about 45%, compared with the event detection with a single water parameter algorithm, S-STED. Moreover, the proposed M-STED can exhibit better performance in terms of detection delay and scalability.

  18. Improved EDELWEISS-III sensitivity for low-mass WIMPs using a profile likelihood approach

    Energy Technology Data Exchange (ETDEWEB)

    Hehn, L. [Karlsruher Institut fuer Technologie, Institut fuer Kernphysik, Karlsruhe (Germany); Armengaud, E.; Boissiere, T. de; Gros, M.; Navick, X.F.; Nones, C.; Paul, B. [CEA Saclay, DSM/IRFU, Gif-sur-Yvette Cedex (France); Arnaud, Q. [Univ Lyon, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Lyon (France); Queen' s University, Kingston (Canada); Augier, C.; Billard, J.; Cazes, A.; Charlieux, F.; Jesus, M. de; Gascon, J.; Juillard, A.; Queguiner, E.; Sanglard, V.; Vagneron, L. [Univ Lyon, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Lyon (France); Benoit, A.; Camus, P. [Institut Neel, CNRS/UJF, Grenoble (France); Berge, L.; Chapellier, M.; Dumoulin, L.; Giuliani, A.; Le-Sueur, H.; Marnieros, S.; Olivieri, E.; Poda, D. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Bluemer, J. [Karlsruher Institut fuer Technologie, Institut fuer Kernphysik, Karlsruhe (Germany); Karlsruher Institut fuer Technologie, Institut fuer Experimentelle Kernphysik, Karlsruhe (Germany); Broniatowski, A. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Karlsruher Institut fuer Technologie, Institut fuer Experimentelle Kernphysik, Karlsruhe (Germany); Eitel, K.; Kozlov, V.; Siebenborn, B. [Karlsruher Institut fuer Technologie, Institut fuer Kernphysik, Karlsruhe (Germany); Foerster, N.; Heuermann, G.; Scorza, S. [Karlsruher Institut fuer Technologie, Institut fuer Experimentelle Kernphysik, Karlsruhe (Germany); Jin, Y. [Laboratoire de Photonique et de Nanostructures, CNRS, Route de Nozay, Marcoussis (France); Kefelian, C. [Univ Lyon, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Lyon (France); Karlsruher Institut fuer Technologie, Institut fuer Experimentelle Kernphysik, Karlsruhe (Germany); Kleifges, M.; Tcherniakhovski, D.; Weber, M. [Karlsruher Institut fuer Technologie, Institut fuer Prozessdatenverarbeitung und Elektronik, Karlsruhe (Germany); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Kudryavtsev, V.A. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Pari, P. [CEA Saclay, DSM/IRAMIS, Gif-sur-Yvette (France); Piro, M.C. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Rensselaer Polytechnic Institute, Troy, NY (United States); Rozov, S.; Yakushev, E. [JINR, Laboratory of Nuclear Problems, Dubna, Moscow Region (Russian Federation); Schmidt, B. [Karlsruher Institut fuer Technologie, Institut fuer Kernphysik, Karlsruhe (Germany); Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2016-10-15

    We report on a dark matter search for a Weakly Interacting Massive Particle (WIMP) in the mass range m{sub χ} element of [4, 30] GeV/c{sup 2} with the EDELWEISS-III experiment. A 2D profile likelihood analysis is performed on data from eight selected detectors with the lowest energy thresholds leading to a combined fiducial exposure of 496 kg-days. External backgrounds from γ- and β-radiation, recoils from {sup 206}Pb and neutrons as well as detector intrinsic backgrounds were modelled from data outside the region of interest and constrained in the analysis. The basic data selection and most of the background models are the same as those used in a previously published analysis based on boosted decision trees (BDT) [1]. For the likelihood approach applied in the analysis presented here, a larger signal efficiency and a subtraction of the expected background lead to a higher sensitivity, especially for the lowest WIMP masses probed. No statistically significant signal was found and upper limits on the spin-independent WIMP-nucleon scattering cross section can be set with a hypothesis test based on the profile likelihood test statistics. The 90 % C.L. exclusion limit set for WIMPs with m{sub χ} = 4 GeV/c{sup 2} is 1.6 x 10{sup -39} cm{sup 2}, which is an improvement of a factor of seven with respect to the BDT-based analysis. For WIMP masses above 15 GeV/c{sup 2} the exclusion limits found with both analyses are in good agreement. (orig.)

  19. Individual differences in event-based prospective memory: Evidence for multiple processes supporting cue detection.

    Science.gov (United States)

    Brewer, Gene A; Knight, Justin B; Marsh, Richard L; Unsworth, Nash

    2010-04-01

    The multiprocess view proposes that different processes can be used to detect event-based prospective memory cues, depending in part on the specificity of the cue. According to this theory, attentional processes are not necessary to detect focal cues, whereas detection of nonfocal cues requires some form of controlled attention. This notion was tested using a design in which we compared performance on a focal and on a nonfocal prospective memory task by participants with high or low working memory capacity. An interaction was found, such that participants with high and low working memory performed equally well on the focal task, whereas the participants with high working memory performed significantly better on the nonfocal task than did their counterparts with low working memory. Thus, controlled attention was only necessary for detecting event-based prospective memory cues in the nonfocal task. These results have implications for theories of prospective memory, the processes necessary for cue detection, and the successful fulfillment of intentions.

  20. On Event/Time Triggered and Distributed Analysis of a WSN System for Event Detection, Using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Sofia Maria Dima

    2016-01-01

    Full Text Available Event detection in realistic WSN environments is a critical research domain, while the environmental monitoring comprises one of its most pronounced applications. Although efforts related to the environmental applications have been presented in the current literature, there is a significant lack of investigation on the performance of such systems, when applied in wireless environments. Aiming at addressing this shortage, in this paper an advanced multimodal approach is followed based on fuzzy logic. The proposed fuzzy inference system (FIS is implemented on TelosB motes and evaluates the probability of fire detection while aiming towards power conservation. Additionally to a straightforward centralized approach, a distributed implementation of the above FIS is also proposed, aiming towards network congestion reduction while optimally distributing the energy consumption among network nodes so as to maximize network lifetime. Moreover this work proposes an event based execution of the aforementioned FIS aiming to further reduce the computational as well as the communication cost, compared to a periodical time triggered FIS execution. As a final contribution, performance metrics acquired from all the proposed FIS implementation techniques are thoroughly compared and analyzed with respect to critical network conditions aiming to offer realistic evaluation and thus objective conclusions’ extraction.

  1. Study and optimization of bolometers designed to measure both ionization and heat in order to detect black matter; Etude et optimisation de bolometres a mesure simultanee de l`ionisation et de la chaleur pour la recherche de matiere noire

    Energy Technology Data Exchange (ETDEWEB)

    Navick, X F

    1997-09-25

    The detection of black matter in the form of wimp (weakly interactive massive particle) requires the identification of the incident particle so that events due to wimp interactions can be set apart from events due to surrounding radioactivity. Bolometers allow to measure both the energy deposited and the ionization made by a particle. The amount of energy is determined by calorimetry. Wimp detection implies bolometers to run at very low temperature. After a presentation of particle interactions with matter, this thesis describes the physical phenomena involved in heat and ionization measurements. The behaviour of semiconductors at low temperature is investigated and qualitative expectations are drawn about the working of metal-semiconductor interface and the pin diode. An experimental setting is presented. The operating voltage needs to be very low in order to be the least disturbing possible. At so low voltage, a decrease of the ionization signal in terms of time appears. It is shown that this phenomenon is linked to the level density in the forbidden band of the semiconductor and to the intensity of infrared radiation reaching the detector. (A.C.) 193 refs.

  2. An Unsupervised Anomalous Event Detection and Interactive Analysis Framework for Large-scale Satellite Data

    Science.gov (United States)

    LIU, Q.; Lv, Q.; Klucik, R.; Chen, C.; Gallaher, D. W.; Grant, G.; Shang, L.

    2016-12-01

    Due to the high volume and complexity of satellite data, computer-aided tools for fast quality assessments and scientific discovery are indispensable for scientists in the era of Big Data. In this work, we have developed a framework for automated anomalous event detection in massive satellite data. The framework consists of a clustering-based anomaly detection algorithm and a cloud-based tool for interactive analysis of detected anomalies. The algorithm is unsupervised and requires no prior knowledge of the data (e.g., expected normal pattern or known anomalies). As such, it works for diverse data sets, and performs well even in the presence of missing and noisy data. The cloud-based tool provides an intuitive mapping interface that allows users to interactively analyze anomalies using multiple features. As a whole, our framework can (1) identify outliers in a spatio-temporal context, (2) recognize and distinguish meaningful anomalous events from individual outliers, (3) rank those events based on "interestingness" (e.g., rareness or total number of outliers) defined by users, and (4) enable interactively query, exploration, and analysis of those anomalous events. In this presentation, we will demonstrate the effectiveness and efficiency of our framework in the application of detecting data quality issues and unusual natural events using two satellite datasets. The techniques and tools developed in this project are applicable for a diverse set of satellite data and will be made publicly available for scientists in early 2017.

  3. Detection of unusual events and trends in complex non-stationary data streams

    International Nuclear Information System (INIS)

    Charlton-Perez, C.; Perez, R.B.; Protopopescu, V.; Worley, B.A.

    2011-01-01

    The search for unusual events and trends hidden in multi-component, nonlinear, non-stationary, noisy signals is extremely important for diverse applications, ranging from power plant operation to homeland security. In the context of this work, we define an unusual event as a local signal disturbance and a trend as a continuous carrier of information added to and different from the underlying baseline dynamics. The goal of this paper is to investigate the feasibility of detecting hidden events inside intermittent signal data sets corrupted by high levels of noise, by using the Hilbert-Huang empirical mode decomposition method.

  4. Method for detecting binding events using micro-X-ray fluorescence spectrometry

    Science.gov (United States)

    Warner, Benjamin P.; Havrilla, George J.; Mann, Grace

    2010-12-28

    Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

  5. Why conventional detection methods fail in identifying the existence of contamination events.

    Science.gov (United States)

    Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

    2016-04-15

    Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effect of parameters in moving average method for event detection enhancement using phase sensitive OTDR

    Science.gov (United States)

    Kwon, Yong-Seok; Naeem, Khurram; Jeon, Min Yong; Kwon, Il-bum

    2017-04-01

    We analyze the relations of parameters in moving average method to enhance the event detectability of phase sensitive optical time domain reflectometer (OTDR). If the external events have unique frequency of vibration, then the control parameters of moving average method should be optimized in order to detect these events efficiently. A phase sensitive OTDR was implemented by a pulsed light source, which is composed of a laser diode, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a fiber Bragg grating filter, and a light receiving part, which has a photo-detector and high speed data acquisition system. The moving average method is operated with the control parameters: total number of raw traces, M, number of averaged traces, N, and step size of moving, n. The raw traces are obtained by the phase sensitive OTDR with sound signals generated by a speaker. Using these trace data, the relation of the control parameters is analyzed. In the result, if the event signal has one frequency, then the optimal values of N, n are existed to detect the event efficiently.

  7. Secure access control and large scale robust representation for online multimedia event detection.

    Science.gov (United States)

    Liu, Changyu; Lu, Bin; Li, Huiling

    2014-01-01

    We developed an online multimedia event detection (MED) system. However, there are a secure access control issue and a large scale robust representation issue when we want to integrate traditional event detection algorithms into the online environment. For the first issue, we proposed a tree proxy-based and service-oriented access control (TPSAC) model based on the traditional role based access control model. Verification experiments were conducted on the CloudSim simulation platform, and the results showed that the TPSAC model is suitable for the access control of dynamic online environments. For the second issue, inspired by the object-bank scene descriptor, we proposed a 1000-object-bank (1000OBK) event descriptor. Feature vectors of the 1000OBK were extracted from response pyramids of 1000 generic object detectors which were trained on standard annotated image datasets, such as the ImageNet dataset. A spatial bag of words tiling approach was then adopted to encode these feature vectors for bridging the gap between the objects and events. Furthermore, we performed experiments in the context of event classification on the challenging TRECVID MED 2012 dataset, and the results showed that the robust 1000OBK event descriptor outperforms the state-of-the-art approaches.

  8. Secure Access Control and Large Scale Robust Representation for Online Multimedia Event Detection

    Directory of Open Access Journals (Sweden)

    Changyu Liu

    2014-01-01

    Full Text Available We developed an online multimedia event detection (MED system. However, there are a secure access control issue and a large scale robust representation issue when we want to integrate traditional event detection algorithms into the online environment. For the first issue, we proposed a tree proxy-based and service-oriented access control (TPSAC model based on the traditional role based access control model. Verification experiments were conducted on the CloudSim simulation platform, and the results showed that the TPSAC model is suitable for the access control of dynamic online environments. For the second issue, inspired by the object-bank scene descriptor, we proposed a 1000-object-bank (1000OBK event descriptor. Feature vectors of the 1000OBK were extracted from response pyramids of 1000 generic object detectors which were trained on standard annotated image datasets, such as the ImageNet dataset. A spatial bag of words tiling approach was then adopted to encode these feature vectors for bridging the gap between the objects and events. Furthermore, we performed experiments in the context of event classification on the challenging TRECVID MED 2012 dataset, and the results showed that the robust 1000OBK event descriptor outperforms the state-of-the-art approaches.

  9. Use of wireless sensor networks for distributed event detection in disaster management applications

    NARCIS (Netherlands)

    Bahrepour, M.; Meratnia, Nirvana; Poel, Mannes; Taghikhaki, Zahra; Havinga, Paul J.M.

    Recently, wireless sensor networks (WSNs) have become mature enough to go beyond being simple fine-grained continuous monitoring platforms and have become one of the enabling technologies for early-warning disaster systems. Event detection functionality of WSNs can be of great help and importance

  10. A robust neural network-based approach for microseismic event detection

    KAUST Repository

    Akram, Jubran; Ovcharenko, Oleg; Peter, Daniel

    2017-01-01

    We present an artificial neural network based approach for robust event detection from low S/N waveforms. We use a feed-forward network with a single hidden layer that is tuned on a training dataset and later applied on the entire example dataset

  11. Process variant comparison: using event logs to detect differences in behavior and business rules

    NARCIS (Netherlands)

    Bolt, A.; de Leoni, M.; van der Aalst, W.M.P.

    2018-01-01

    This paper addresses the problem of comparing different variants of the same process. We aim to detect relevant differences between processes based on what was recorded in event logs. We use transition systems to model behavior and to highlight differences. Transition systems are annotated with

  12. A novel seizure detection algorithm informed by hidden Markov model event states

    Science.gov (United States)

    Baldassano, Steven; Wulsin, Drausin; Ung, Hoameng; Blevins, Tyler; Brown, Mesha-Gay; Fox, Emily; Litt, Brian

    2016-06-01

    Objective. Recently the FDA approved the first responsive, closed-loop intracranial device to treat epilepsy. Because these devices must respond within seconds of seizure onset and not miss events, they are tuned to have high sensitivity, leading to frequent false positive stimulations and decreased battery life. In this work, we propose a more robust seizure detection model. Approach. We use a Bayesian nonparametric Markov switching process to parse intracranial EEG (iEEG) data into distinct dynamic event states. Each event state is then modeled as a multidimensional Gaussian distribution to allow for predictive state assignment. By detecting event states highly specific for seizure onset zones, the method can identify precise regions of iEEG data associated with the transition to seizure activity, reducing false positive detections associated with interictal bursts. The seizure detection algorithm was translated to a real-time application and validated in a small pilot study using 391 days of continuous iEEG data from two dogs with naturally occurring, multifocal epilepsy. A feature-based seizure detector modeled after the NeuroPace RNS System was developed as a control. Main results. Our novel seizure detection method demonstrated an improvement in false negative rate (0/55 seizures missed versus 2/55 seizures missed) as well as a significantly reduced false positive rate (0.0012 h versus 0.058 h-1). All seizures were detected an average of 12.1 ± 6.9 s before the onset of unequivocal epileptic activity (unequivocal epileptic onset (UEO)). Significance. This algorithm represents a computationally inexpensive, individualized, real-time detection method suitable for implantable antiepileptic devices that may considerably reduce false positive rate relative to current industry standards.

  13. GENIUS and the Genius TF: A New Observatory for WIMP Dark Matter and Neutrinoless Double Beta Decay

    OpenAIRE

    Klapdor-Kleingrothaus, H. V.; Majorovits, B.

    2001-01-01

    The GENIUS proposal is described and some of it's physics potential is outlined. Also in the light of the contradictive results from the DAMA and CDMS experiments the Genius TF, a new experimental setup is proposed. The Genius TF could probe the DAMA evidence region using the WIMP nucleus recoil signal and WIMP annual modulation signature simultaneously. Besides that it can prove the long term feasibility of the detector technique to be implemented into the GENIUS setup and will in this sense...

  14. Events

    Directory of Open Access Journals (Sweden)

    Igor V. Karyakin

    2016-02-01

    Full Text Available The 9th ARRCN Symposium 2015 was held during 21st–25th October 2015 at the Novotel Hotel, Chumphon, Thailand, one of the most favored travel destinations in Asia. The 10th ARRCN Symposium 2017 will be held during October 2017 in the Davao, Philippines. International Symposium on the Montagu's Harrier (Circus pygargus «The Montagu's Harrier in Europe. Status. Threats. Protection», organized by the environmental organization «Landesbund für Vogelschutz in Bayern e.V.» (LBV was held on November 20-22, 2015 in Germany. The location of this event was the city of Wurzburg in Bavaria.

  15. Event detection and exception handling strategies in the ASDEX Upgrade discharge control system

    International Nuclear Information System (INIS)

    Treutterer, W.; Neu, G.; Rapson, C.; Raupp, G.; Zasche, D.; Zehetbauer, T.

    2013-01-01

    Highlights: •Event detection and exception handling is integrated in control system architecture. •Pulse control with local exception handling and pulse supervision with central exception handling are strictly separated. •Local exception handling limits the effect of an exception to a minimal part of the controlled system. •Central Exception Handling solves problems requiring coordinated action of multiple control components. -- Abstract: Thermonuclear plasmas are governed by nonlinear characteristics: plasma operation can be classified into scenarios with pronounced features like L and H-mode, ELMs or MHD activity. Transitions between them may be treated as events. Similarly, technical systems are also subject to events such as failure of measurement sensors, actuator saturation or violation of machine and plant operation limits. Such situations often are handled with a mixture of pulse abortion and iteratively improved pulse schedule reference programming. In case of protection-relevant events, however, the complexity of even a medium-sized device as ASDEX Upgrade requires a sophisticated and coordinated shutdown procedure rather than a simple stop of the pulse. The detection of events and their intelligent handling by the control system has been shown to be valuable also in terms of saving experiment time and cost. This paper outlines how ASDEX Upgrade's discharge control system (DCS) detects events and handles exceptions in two stages: locally and centrally. The goal of local exception handling is to limit the effect of an unexpected or asynchronous event to a minimal part of the controlled system. Thus, local exception handling facilitates robustness to failures but keeps the decision structures lean. A central state machine deals with exceptions requiring coordinated action of multiple control components. DCS implements the state machine by means of pulse schedule segments containing pre-programmed waveforms to define discharge goal and control

  16. Event detection and exception handling strategies in the ASDEX Upgrade discharge control system

    Energy Technology Data Exchange (ETDEWEB)

    Treutterer, W., E-mail: Wolfgang.Treutterer@ipp.mpg.de; Neu, G.; Rapson, C.; Raupp, G.; Zasche, D.; Zehetbauer, T.

    2013-10-15

    Highlights: •Event detection and exception handling is integrated in control system architecture. •Pulse control with local exception handling and pulse supervision with central exception handling are strictly separated. •Local exception handling limits the effect of an exception to a minimal part of the controlled system. •Central Exception Handling solves problems requiring coordinated action of multiple control components. -- Abstract: Thermonuclear plasmas are governed by nonlinear characteristics: plasma operation can be classified into scenarios with pronounced features like L and H-mode, ELMs or MHD activity. Transitions between them may be treated as events. Similarly, technical systems are also subject to events such as failure of measurement sensors, actuator saturation or violation of machine and plant operation limits. Such situations often are handled with a mixture of pulse abortion and iteratively improved pulse schedule reference programming. In case of protection-relevant events, however, the complexity of even a medium-sized device as ASDEX Upgrade requires a sophisticated and coordinated shutdown procedure rather than a simple stop of the pulse. The detection of events and their intelligent handling by the control system has been shown to be valuable also in terms of saving experiment time and cost. This paper outlines how ASDEX Upgrade's discharge control system (DCS) detects events and handles exceptions in two stages: locally and centrally. The goal of local exception handling is to limit the effect of an unexpected or asynchronous event to a minimal part of the controlled system. Thus, local exception handling facilitates robustness to failures but keeps the decision structures lean. A central state machine deals with exceptions requiring coordinated action of multiple control components. DCS implements the state machine by means of pulse schedule segments containing pre-programmed waveforms to define discharge goal and control

  17. Automatic detection of adverse events to predict drug label changes using text and data mining techniques.

    Science.gov (United States)

    Gurulingappa, Harsha; Toldo, Luca; Rajput, Abdul Mateen; Kors, Jan A; Taweel, Adel; Tayrouz, Yorki

    2013-11-01

    The aim of this study was to assess the impact of automatically detected adverse event signals from text and open-source data on the prediction of drug label changes. Open-source adverse effect data were collected from FAERS, Yellow Cards and SIDER databases. A shallow linguistic relation extraction system (JSRE) was applied for extraction of adverse effects from MEDLINE case reports. Statistical approach was applied on the extracted datasets for signal detection and subsequent prediction of label changes issued for 29 drugs by the UK Regulatory Authority in 2009. 76% of drug label changes were automatically predicted. Out of these, 6% of drug label changes were detected only by text mining. JSRE enabled precise identification of four adverse drug events from MEDLINE that were undetectable otherwise. Changes in drug labels can be predicted automatically using data and text mining techniques. Text mining technology is mature and well-placed to support the pharmacovigilance tasks. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Ontology-based knowledge management for personalized adverse drug events detection.

    Science.gov (United States)

    Cao, Feng; Sun, Xingzhi; Wang, Xiaoyuan; Li, Bo; Li, Jing; Pan, Yue

    2011-01-01

    Since Adverse Drug Event (ADE) has become a leading cause of death around the world, there arises high demand for helping clinicians or patients to identify possible hazards from drug effects. Motivated by this, we present a personalized ADE detection system, with the focus on applying ontology-based knowledge management techniques to enhance ADE detection services. The development of electronic health records makes it possible to automate the personalized ADE detection, i.e., to take patient clinical conditions into account during ADE detection. Specifically, we define the ADE ontology to uniformly manage the ADE knowledge from multiple sources. We take advantage of the rich semantics from the terminology SNOMED-CT and apply it to ADE detection via the semantic query and reasoning.

  19. Detections of Planets in Binaries Through the Channel of Chang–Refsdal Gravitational Lensing Events

    Energy Technology Data Exchange (ETDEWEB)

    Han, Cheongho [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Shin, In-Gu; Jung, Youn Kil [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2017-02-01

    Chang–Refsdal (C–R) lensing, which refers to the gravitational lensing of a point mass perturbed by a constant external shear, provides a good approximation in describing lensing behaviors of either a very wide or a very close binary lens. C–R lensing events, which are identified by short-term anomalies near the peak of high-magnification lensing light curves, are routinely detected from lensing surveys, but not much attention is paid to them. In this paper, we point out that C–R lensing events provide an important channel to detect planets in binaries, both in close and wide binary systems. Detecting planets through the C–R lensing event channel is possible because the planet-induced perturbation occurs in the same region of the C–R lensing-induced anomaly and thus the existence of the planet can be identified by the additional deviation in the central perturbation. By presenting the analysis of the actually observed C–R lensing event OGLE-2015-BLG-1319, we demonstrate that dense and high-precision coverage of a C–R lensing-induced perturbation can provide a strong constraint on the existence of a planet in a wide range of planet parameters. The sample of an increased number of microlensing planets in binary systems will provide important observational constraints in giving shape to the details of planet formation, which have been restricted to the case of single stars to date.

  20. Neutrinos from WIMP annihilations in the Sun including neutrino oscillations

    International Nuclear Information System (INIS)

    Blennow, Mattias; Edsjö, Joakim; Ohlsson, Tommy

    2011-01-01

    The prospects to detect neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.

  1. Neutrinos from WIMP annihilations in the Sun including neutrino oscillations

    International Nuclear Information System (INIS)

    Blennow, Mattias; Edsjoe, Joakim; Ohlsson, Tommy

    2006-01-01

    The prospects for detecting neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes

  2. Fundamental aspects of seismic event detection, magnitude estimation and their interrelation

    International Nuclear Information System (INIS)

    Ringdal, F.

    1977-01-01

    The main common subject of the papers forming this thesis is statistical model development within the seismological disciplines of seismic event detection and event magnitude estimation. As more high quality seismic data become available as a result of recent seismic network developments, the opportunity will exist for large scale application and further refinement of these models. It is hoped that the work presented here will facilitate improved understanding of the basic issues, both within earthquake-explosion discrimination, in the framework of which most of this work originated, and in seismology in general. (Auth.)

  3. Facilitating adverse drug event detection in pharmacovigilance databases using molecular structure similarity: application to rhabdomyolysis

    Science.gov (United States)

    Vilar, Santiago; Harpaz, Rave; Chase, Herbert S; Costanzi, Stefano; Rabadan, Raul

    2011-01-01

    Background Adverse drug events (ADE) cause considerable harm to patients, and consequently their detection is critical for patient safety. The US Food and Drug Administration maintains an adverse event reporting system (AERS) to facilitate the detection of ADE in drugs. Various data mining approaches have been developed that use AERS to detect signals identifying associations between drugs and ADE. The signals must then be monitored further by domain experts, which is a time-consuming task. Objective To develop a new methodology that combines existing data mining algorithms with chemical information by analysis of molecular fingerprints to enhance initial ADE signals generated from AERS, and to provide a decision support mechanism to facilitate the identification of novel adverse events. Results The method achieved a significant improvement in precision in identifying known ADE, and a more than twofold signal enhancement when applied to the ADE rhabdomyolysis. The simplicity of the method assists in highlighting the etiology of the ADE by identifying structurally similar drugs. A set of drugs with strong evidence from both AERS and molecular fingerprint-based modeling is constructed for further analysis. Conclusion The results demonstrate that the proposed methodology could be used as a pharmacovigilance decision support tool to facilitate ADE detection. PMID:21946238

  4. Microfluidic Arrayed Lab-On-A-Chip for Electrochemical Capacitive Detection of DNA Hybridization Events.

    Science.gov (United States)

    Ben-Yoav, Hadar; Dykstra, Peter H; Bentley, William E; Ghodssi, Reza

    2017-01-01

    A microfluidic electrochemical lab-on-a-chip (LOC) device for DNA hybridization detection has been developed. The device comprises a 3 × 3 array of microelectrodes integrated with a dual layer microfluidic valved manipulation system that provides controlled and automated capabilities for high throughput analysis of microliter volume samples. The surface of the microelectrodes is functionalized with single-stranded DNA (ssDNA) probes which enable specific detection of complementary ssDNA targets. These targets are detected by a capacitive technique which measures dielectric variation at the microelectrode-electrolyte interface due to DNA hybridization events. A quantitative analysis of the hybridization events is carried out based on a sensing modeling that includes detailed analysis of energy storage and dissipation components. By calculating these components during hybridization events the device is able to demonstrate specific and dose response sensing characteristics. The developed microfluidic LOC for DNA hybridization detection offers a technology for real-time and label-free assessment of genetic markers outside of laboratory settings, such as at the point-of-care or in-field environmental monitoring.

  5. Simultaneous Event-Triggered Fault Detection and Estimation for Stochastic Systems Subject to Deception Attacks.

    Science.gov (United States)

    Li, Yunji; Wu, QingE; Peng, Li

    2018-01-23

    In this paper, a synthesized design of fault-detection filter and fault estimator is considered for a class of discrete-time stochastic systems in the framework of event-triggered transmission scheme subject to unknown disturbances and deception attacks. A random variable obeying the Bernoulli distribution is employed to characterize the phenomena of the randomly occurring deception attacks. To achieve a fault-detection residual is only sensitive to faults while robust to disturbances, a coordinate transformation approach is exploited. This approach can transform the considered system into two subsystems and the unknown disturbances are removed from one of the subsystems. The gain of fault-detection filter is derived by minimizing an upper bound of filter error covariance. Meanwhile, system faults can be reconstructed by the remote fault estimator. An recursive approach is developed to obtain fault estimator gains as well as guarantee the fault estimator performance. Furthermore, the corresponding event-triggered sensor data transmission scheme is also presented for improving working-life of the wireless sensor node when measurement information are aperiodically transmitted. Finally, a scaled version of an industrial system consisting of local PC, remote estimator and wireless sensor node is used to experimentally evaluate the proposed theoretical results. In particular, a novel fault-alarming strategy is proposed so that the real-time capacity of fault-detection is guaranteed when the event condition is triggered.

  6. Integrated hydraulic and organophosphate pesticide injection simulations for enhancing event detection in water distribution systems.

    Science.gov (United States)

    Schwartz, Rafi; Lahav, Ori; Ostfeld, Avi

    2014-10-15

    As a complementary step towards solving the general event detection problem of water distribution systems, injection of the organophosphate pesticides, chlorpyrifos (CP) and parathion (PA), were simulated at various locations within example networks and hydraulic parameters were calculated over 24-h duration. The uniqueness of this study is that the chemical reactions and byproducts of the contaminants' oxidation were also simulated, as well as other indicative water quality parameters such as alkalinity, acidity, pH and the total concentration of free chlorine species. The information on the change in water quality parameters induced by the contaminant injection may facilitate on-line detection of an actual event involving this specific substance and pave the way to development of a generic methodology for detecting events involving introduction of pesticides into water distribution systems. Simulation of the contaminant injection was performed at several nodes within two different networks. For each injection, concentrations of the relevant contaminants' mother and daughter species, free chlorine species and water quality parameters, were simulated at nodes downstream of the injection location. The results indicate that injection of these substances can be detected at certain conditions by a very rapid drop in Cl2, functioning as the indicative parameter, as well as a drop in alkalinity concentration and a small decrease in pH, both functioning as supporting parameters, whose usage may reduce false positive alarms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Detection of visual events along the apparent motion trace in patients with paranoid schizophrenia.

    Science.gov (United States)

    Sanders, Lia Lira Olivier; Muckli, Lars; de Millas, Walter; Lautenschlager, Marion; Heinz, Andreas; Kathmann, Norbert; Sterzer, Philipp

    2012-07-30

    Dysfunctional prediction in sensory processing has been suggested as a possible causal mechanism in the development of delusions in patients with schizophrenia. Previous studies in healthy subjects have shown that while the perception of apparent motion can mask visual events along the illusory motion trace, such motion masking is reduced when events are spatio-temporally compatible with the illusion, and, therefore, predictable. Here we tested the hypothesis that this specific detection advantage for predictable target stimuli on the apparent motion trace is reduced in patients with paranoid schizophrenia. Our data show that, although target detection along the illusory motion trace is generally impaired, both patients and healthy control participants detect predictable targets more often than unpredictable targets. Patients had a stronger motion masking effect when compared to controls. However, patients showed the same advantage in the detection of predictable targets as healthy control subjects. Our findings reveal stronger motion masking but intact prediction of visual events along the apparent motion trace in patients with paranoid schizophrenia and suggest that the sensory prediction mechanism underlying apparent motion is not impaired in paranoid schizophrenia. Copyright © 2012. Published by Elsevier Ireland Ltd.

  8. Hazardous Traffic Event Detection Using Markov Blanket and Sequential Minimal Optimization (MB-SMO

    Directory of Open Access Journals (Sweden)

    Lixin Yan

    2016-07-01

    Full Text Available The ability to identify hazardous traffic events is already considered as one of the most effective solutions for reducing the occurrence of crashes. Only certain particular hazardous traffic events have been studied in previous studies, which were mainly based on dedicated video stream data and GPS data. The objective of this study is twofold: (1 the Markov blanket (MB algorithm is employed to extract the main factors associated with hazardous traffic events; (2 a model is developed to identify hazardous traffic event using driving characteristics, vehicle trajectory, and vehicle position data. Twenty-two licensed drivers were recruited to carry out a natural driving experiment in Wuhan, China, and multi-sensor information data were collected for different types of traffic events. The results indicated that a vehicle’s speed, the standard deviation of speed, the standard deviation of skin conductance, the standard deviation of brake pressure, turn signal, the acceleration of steering, the standard deviation of acceleration, and the acceleration in Z (G have significant influences on hazardous traffic events. The sequential minimal optimization (SMO algorithm was adopted to build the identification model, and the accuracy of prediction was higher than 86%. Moreover, compared with other detection algorithms, the MB-SMO algorithm was ranked best in terms of the prediction accuracy. The conclusions can provide reference evidence for the development of dangerous situation warning products and the design of intelligent vehicles.

  9. Latency and mode of error detection as reflected in Swedish licensee event reports

    Energy Technology Data Exchange (ETDEWEB)

    Svenson, Ola; Salo, Ilkka [Stockholm Univ., (Sweden). Dept. of Psychology

    2002-03-01

    Licensee event reports (LERs) from an industry provide important information feedback about safety to the industry itself, the regulators and to the public. LERs from four nuclear power reactors were analyzed to find out about detection times, mode of detection and qualitative differences in reports from different reactors. The reliability of the coding was satisfactory and measured as the covariance between the ratings from two independent judges. The results showed differences in detection time across the reactors. On the average about ten percent of the errors remained undetected for 100 weeks or more, but the great majority of errors were detected soon after their first appearance in the plant. On the average 40 percent of the errors were detected in regular tests and 40 per cent through alarms. Operators found about 10 per cent of the errors through noticing something abnormal in the plant. The remaining errors were detected in various other ways. There were qualitative differences between the LERs from the different reactors reflecting the different conditions in the plants. The number of reports differed by a magnitude 1:2 between the different plants. However, a greater number of LERs can indicate both higher safety standards (e.g., a greater willingness to report all possible events to be able to learn from them) and lower safety standards (e.g., reporting as few events as possible to make a good impression). It was pointed out that LERs are indispensable in order to maintain safety of an industry and that the differences between plants found in the analyses of this study indicate how error reports can be used to initiate further investigations for improved safety.

  10. Latency and mode of error detection as reflected in Swedish licensee event reports

    International Nuclear Information System (INIS)

    Svenson, Ola; Salo, Ilkka

    2002-03-01

    Licensee event reports (LERs) from an industry provide important information feedback about safety to the industry itself, the regulators and to the public. LERs from four nuclear power reactors were analyzed to find out about detection times, mode of detection and qualitative differences in reports from different reactors. The reliability of the coding was satisfactory and measured as the covariance between the ratings from two independent judges. The results showed differences in detection time across the reactors. On the average about ten percent of the errors remained undetected for 100 weeks or more, but the great majority of errors were detected soon after their first appearance in the plant. On the average 40 percent of the errors were detected in regular tests and 40 per cent through alarms. Operators found about 10 per cent of the errors through noticing something abnormal in the plant. The remaining errors were detected in various other ways. There were qualitative differences between the LERs from the different reactors reflecting the different conditions in the plants. The number of reports differed by a magnitude 1:2 between the different plants. However, a greater number of LERs can indicate both higher safety standards (e.g., a greater willingness to report all possible events to be able to learn from them) and lower safety standards (e.g., reporting as few events as possible to make a good impression). It was pointed out that LERs are indispensable in order to maintain safety of an industry and that the differences between plants found in the analyses of this study indicate how error reports can be used to initiate further investigations for improved safety

  11. Detection of Unusual Events and Trends in Complex Non-Stationary Data Streams

    International Nuclear Information System (INIS)

    Perez, Rafael B.; Protopopescu, Vladimir A.; Worley, Brian Addison; Perez, Cristina

    2006-01-01

    The search for unusual events and trends hidden in multi-component, nonlinear, non-stationary, noisy signals is extremely important for a host of different applications, ranging from nuclear power plant and electric grid operation to internet traffic and implementation of non-proliferation protocols. In the context of this work, we define an unusual event as a local signal disturbance and a trend as a continuous carrier of information added to and different from the underlying baseline dynamics. The goal of this paper is to investigate the feasibility of detecting hidden intermittent events inside non-stationary signal data sets corrupted by high levels of noise, by using the Hilbert-Huang empirical mode decomposition method

  12. Energy Reconstruction for Events Detected in TES X-ray Detectors

    Science.gov (United States)

    Ceballos, M. T.; Cardiel, N.; Cobo, B.

    2015-09-01

    The processing of the X-ray events detected by a TES (Transition Edge Sensor) device (such as the one that will be proposed in the ESA AO call for instruments for the Athena mission (Nandra et al. 2013) as a high spectral resolution instrument, X-IFU (Barret et al. 2013)), is a several step procedure that starts with the detection of the current pulses in a noisy signal and ends up with their energy reconstruction. For this last stage, an energy calibration process is required to convert the pseudo energies measured in the detector to the real energies of the incoming photons, accounting for possible nonlinearity effects in the detector. We present the details of the energy calibration algorithm we implemented as the last part of the Event Processing software that we are developing for the X-IFU instrument, that permits the calculation of the calibration constants in an analytical way.

  13. A novel CUSUM-based approach for event detection in smart metering

    Science.gov (United States)

    Zhu, Zhicheng; Zhang, Shuai; Wei, Zhiqiang; Yin, Bo; Huang, Xianqing

    2018-03-01

    Non-intrusive load monitoring (NILM) plays such a significant role in raising consumer awareness on household electricity use to reduce overall energy consumption in the society. With regard to monitoring low power load, many researchers have introduced CUSUM into the NILM system, since the traditional event detection method is not as effective as expected. Due to the fact that the original CUSUM faces limitations given the small shift is below threshold, we therefore improve the test statistic which allows permissible deviation to gradually rise as the data size increases. This paper proposes a novel event detection and corresponding criterion that could be used in NILM systems to recognize transient states and to help the labelling task. Its performance has been tested in a real scenario where eight different appliances are connected to main line of electric power.

  14. Automatic detection of esophageal pressure events. Is there an alternative to rule-based criteria?

    DEFF Research Database (Denmark)

    Kruse-Andersen, S; Rütz, K; Kolberg, Jens Godsk

    1995-01-01

    of relevant pressure peaks at the various recording levels. Until now, this selection has been performed entirely by rule-based systems, requiring each pressure deflection to fit within predefined rigid numerical limits in order to be detected. However, due to great variations in the shapes of the pressure...... curves generated by muscular contractions, rule-based criteria do not always select the pressure events most relevant for further analysis. We have therefore been searching for a new concept for automatic event recognition. The present study describes a new system, based on the method of neurocomputing.......79-0.99 and accuracies of 0.89-0.98, depending on the recording level within the esophageal lumen. The neural networks often recognized peaks that clearly represented true contractions but that had been rejected by a rule-based system. We conclude that neural networks have potentials for automatic detections...

  15. Power Load Event Detection and Classification Based on Edge Symbol Analysis and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Lei Jiang

    2012-01-01

    Full Text Available Energy signature analysis of power appliance is the core of nonintrusive load monitoring (NILM where the detailed data of the appliances used in houses are obtained by analyzing changes in the voltage and current. This paper focuses on developing an automatic power load event detection and appliance classification based on machine learning. In power load event detection, the paper presents a new transient detection algorithm. By turn-on and turn-off transient waveforms analysis, it can accurately detect the edge point when a device is switched on or switched off. The proposed load classification technique can identify different power appliances with improved recognition accuracy and computational speed. The load classification method is composed of two processes including frequency feature analysis and support vector machine. The experimental results indicated that the incorporation of the new edge detection and turn-on and turn-off transient signature analysis into NILM revealed more information than traditional NILM methods. The load classification method has achieved more than ninety percent recognition rate.

  16. Flow detection via sparse frame analysis for suspicious event recognition in infrared imagery

    Science.gov (United States)

    Fernandes, Henrique C.; Batista, Marcos A.; Barcelos, Celia A. Z.; Maldague, Xavier P. V.

    2013-05-01

    It is becoming increasingly evident that intelligent systems are very bene¯cial for society and that the further development of such systems is necessary to continue to improve society's quality of life. One area that has drawn the attention of recent research is the development of automatic surveillance systems. In our work we outline a system capable of monitoring an uncontrolled area (an outside parking lot) using infrared imagery and recognizing suspicious events in this area. The ¯rst step is to identify moving objects and segment them from the scene's background. Our approach is based on a dynamic background-subtraction technique which robustly adapts detection to illumination changes. It is analyzed only regions where movement is occurring, ignoring in°uence of pixels from regions where there is no movement, to segment moving objects. Regions where movement is occurring are identi¯ed using °ow detection via sparse frame analysis. During the tracking process the objects are classi¯ed into two categories: Persons and Vehicles, based on features such as size and velocity. The last step is to recognize suspicious events that may occur in the scene. Since the objects are correctly segmented and classi¯ed it is possible to identify those events using features such as velocity and time spent motionless in one spot. In this paper we recognize the suspicious event suspicion of object(s) theft from inside a parked vehicle at spot X by a person" and results show that the use of °ow detection increases the recognition of this suspicious event from 78:57% to 92:85%.

  17. Detection of invisible and crucial events: from seismic fluctuations to the war against terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Allegrini, Paolo; Fronzoni, Leone; Grigolini, Paolo; Latora, Vito; Mega, Mirko S.; Palatella, Luigi E-mail: luigi.palatella@df.unipi.it; Rapisarda, Andrea; Vinciguerra, Sergio

    2004-04-01

    We argue that the recent discovery of the non-Poissonian statistics of the seismic main-shocks is a special case of a more general approach to the detection of the distribution of the time increments between one crucial but invisible event and the next. We make the conjecture that the proposed approach can be applied to the analysis of terrorist network with significant benefits for the Intelligence Community.

  18. Automated Feature and Event Detection with SDO AIA and HMI Data

    Science.gov (United States)

    Davey, Alisdair; Martens, P. C. H.; Attrill, G. D. R.; Engell, A.; Farid, S.; Grigis, P. C.; Kasper, J.; Korreck, K.; Saar, S. H.; Su, Y.; Testa, P.; Wills-Davey, M.; Savcheva, A.; Bernasconi, P. N.; Raouafi, N.-E.; Delouille, V. A.; Hochedez, J. F..; Cirtain, J. W.; Deforest, C. E.; Angryk, R. A.; de Moortel, I.; Wiegelmann, T.; Georgouli, M. K.; McAteer, R. T. J.; Hurlburt, N.; Timmons, R.

    The Solar Dynamics Observatory (SDO) represents a new frontier in quantity and quality of solar data. At about 1.5 TB/day, the data will not be easily digestible by solar physicists using the same methods that have been employed for images from previous missions. In order for solar scientists to use the SDO data effectively they need meta-data that will allow them to identify and retrieve data sets that address their particular science questions. We are building a comprehensive computer vision pipeline for SDO, abstracting complete metadata on many of the features and events detectable on the Sun without human intervention. Our project unites more than a dozen individual, existing codes into a systematic tool that can be used by the entire solar community. The feature finding codes will run as part of the SDO Event Detection System (EDS) at the Joint Science Operations Center (JSOC; joint between Stanford and LMSAL). The metadata produced will be stored in the Heliophysics Event Knowledgebase (HEK), which will be accessible on-line for the rest of the world directly or via the Virtual Solar Observatory (VSO) . Solar scientists will be able to use the HEK to select event and feature data to download for science studies.

  19. A Macro-Observation Scheme for Abnormal Event Detection in Daily-Life Video Sequences

    Directory of Open Access Journals (Sweden)

    Chiu Wei-Yao

    2010-01-01

    Full Text Available Abstract We propose a macro-observation scheme for abnormal event detection in daily life. The proposed macro-observation representation records the time-space energy of motions of all moving objects in a scene without segmenting individual object parts. The energy history of each pixel in the scene is instantly updated with exponential weights without explicitly specifying the duration of each activity. Since possible activities in daily life are numerous and distinct from each other and not all abnormal events can be foreseen, images from a video sequence that spans sufficient repetition of normal day-to-day activities are first randomly sampled. A constrained clustering model is proposed to partition the sampled images into groups. The new observed event that has distinct distance from any of the cluster centroids is then classified as an anomaly. The proposed method has been evaluated in daily work of a laboratory and BEHAVE benchmark dataset. The experimental results reveal that it can well detect abnormal events such as burglary and fighting as long as they last for a sufficient duration of time. The proposed method can be used as a support system for the scene that requires full time monitoring personnel.

  20. Detecting adverse events in surgery: comparing events detected by the Veterans Health Administration Surgical Quality Improvement Program and the Patient Safety Indicators.

    Science.gov (United States)

    Mull, Hillary J; Borzecki, Ann M; Loveland, Susan; Hickson, Kathleen; Chen, Qi; MacDonald, Sally; Shin, Marlena H; Cevasco, Marisa; Itani, Kamal M F; Rosen, Amy K

    2014-04-01

    The Patient Safety Indicators (PSIs) use administrative data to screen for select adverse events (AEs). In this study, VA Surgical Quality Improvement Program (VASQIP) chart review data were used as the gold standard to measure the criterion validity of 5 surgical PSIs. Independent chart review was also used to determine reasons for PSI errors. The sensitivity, specificity, and positive predictive value of PSI software version 4.1a were calculated among Veterans Health Administration hospitalizations (2003-2007) reviewed by VASQIP (n = 268,771). Nurses re-reviewed a sample of hospitalizations for which PSI and VASQIP AE detection disagreed. Sensitivities ranged from 31% to 68%, specificities from 99.1% to 99.8%, and positive predictive values from 31% to 72%. Reviewers found that coding errors accounted for some PSI-VASQIP disagreement; some disagreement was also the result of differences in AE definitions. These results suggest that the PSIs have moderate criterion validity; however, some surgical PSIs detect different AEs than VASQIP. Future research should explore using both methods to evaluate surgical quality. Published by Elsevier Inc.

  1. Temporal and spatial predictability of an irrelevant event differently affect detection and memory of items in a visual sequence

    Directory of Open Access Journals (Sweden)

    Junji eOhyama

    2016-02-01

    Full Text Available We examined how the temporal and spatial predictability of a task-irrelevant visual event affects the detection and memory of a visual item embedded in a continuously changing sequence. Participants observed 11 sequentially presented letters, during which a task-irrelevant visual event was either present or absent. Predictabilities of spatial location and temporal position of the event were controlled in 2 × 2 conditions. In the spatially predictable conditions, the event occurred at the same location within the stimulus sequence or at another location, while, in the spatially unpredictable conditions, it occurred at random locations. In the temporally predictable conditions, the event timing was fixed relative to the order of the letters, while in the temporally unpredictable condition, it could not be predicted from the letter order. Participants performed a working memory task and a target detection reaction time task. Memory accuracy was higher for a letter simultaneously presented at the same location as the event in the temporally unpredictable conditions, irrespective of the spatial predictability of the event. On the other hand, the detection reaction times were only faster for a letter simultaneously presented at the same location as the event when the event was both temporally and spatially predictable. Thus, to facilitate ongoing detection processes, an event must be predictable both in space and time, while memory processes are enhanced by temporally unpredictable (i.e., surprising events. Evidently, temporal predictability has differential effects on detection and memory of a visual item embedded in a sequence of images.

  2. Method for the depth corrected detection of ionizing events from a co-planar grids sensor

    Science.gov (United States)

    De Geronimo, Gianluigi [Syosset, NY; Bolotnikov, Aleksey E [South Setauket, NY; Carini, Gabriella [Port Jefferson, NY

    2009-05-12

    A method for the detection of ionizing events utilizing a co-planar grids sensor comprising a semiconductor substrate, cathode electrode, collecting grid and non-collecting grid. The semiconductor substrate is sensitive to ionizing radiation. A voltage less than 0 Volts is applied to the cathode electrode. A voltage greater than the voltage applied to the cathode is applied to the non-collecting grid. A voltage greater than the voltage applied to the non-collecting grid is applied to the collecting grid. The collecting grid and the non-collecting grid are summed and subtracted creating a sum and difference respectively. The difference and sum are divided creating a ratio. A gain coefficient factor for each depth (distance between the ionizing event and the collecting grid) is determined, whereby the difference between the collecting electrode and the non-collecting electrode multiplied by the corresponding gain coefficient is the depth corrected energy of an ionizing event. Therefore, the energy of each ionizing event is the difference between the collecting grid and the non-collecting grid multiplied by the corresponding gain coefficient. The depth of the ionizing event can also be determined from the ratio.

  3. Presentation of the results of a Bayesian automatic event detection and localization program to human analysts

    Science.gov (United States)

    Kushida, N.; Kebede, F.; Feitio, P.; Le Bras, R.

    2016-12-01

    The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been developing and testing NET-VISA (Arora et al., 2013), a Bayesian automatic event detection and localization program, and evaluating its performance in a realistic operational mode. In our preliminary testing at the CTBTO, NET-VISA shows better performance than its currently operating automatic localization program. However, given CTBTO's role and its international context, a new technology should be introduced cautiously when it replaces a key piece of the automatic processing. We integrated the results of NET-VISA into the Analyst Review Station, extensively used by the analysts so that they can check the accuracy and robustness of the Bayesian approach. We expect the workload of the analysts to be reduced because of the better performance of NET-VISA in finding missed events and getting a more complete set of stations than the current system which has been operating for nearly twenty years. The results of a series of tests indicate that the expectations born from the automatic tests, which show an overall overlap improvement of 11%, meaning that the missed events rate is cut by 42%, hold for the integrated interactive module as well. New events are found by analysts, which qualify for the CTBTO Reviewed Event Bulletin, beyond the ones analyzed through the standard procedures. Arora, N., Russell, S., and Sudderth, E., NET-VISA: Network Processing Vertically Integrated Seismic Analysis, 2013, Bull. Seismol. Soc. Am., 103, 709-729.

  4. Prospects for SIMPLE 2000 A large-mass, low-background Superheated Droplet Detector for WIMP searches

    CERN Document Server

    Collar, J I; Girard, T A; Limagne, D; Miley, H S; Waysand, G

    2000-01-01

    SIMPLE 2000 ({\\underline S}uperheated {\\underline I}nstrument for {\\underline M}assive {\\underline P}artic{\\underline {LE}} searches) will consist of an array of eight to sixteen large active mass ($\\sim15$ g) Superheated Droplet Detectors(SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make of SDDs an attractive approach for the detection of Weakly Interacting Massive Particles (WIMPs), namely their intrinsic insensitivity to minimum ionizing particles, high fluorine content, low cost and operation near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from SIMPLE prototype SDDs, as well as on the expected immediate increase in sensitivity of the program, which aims at an exposure of $>$25 kg-day during the year 2000. The ability of modest-mass fluorine-rich detectors to explore regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out.

  5. Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

    Energy Technology Data Exchange (ETDEWEB)

    Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

    2007-01-30

    In the field of nuclear explosion monitoring, it has become a priority to detect, locate, and identify seismic events down to increasingly small magnitudes. The consideration of smaller seismic events has implications for a reliable monitoring regime. Firstly, the number of events to be considered increases greatly; an exponential increase in naturally occurring seismicity is compounded by large numbers of seismic signals generated by human activity. Secondly, the signals from smaller events become more difficult to detect above the background noise and estimates of parameters required for locating the events may be subject to greater errors. Thirdly, events are likely to be observed by a far smaller number of seismic stations, and the reliability of event detection and location using a very limited set of observations needs to be quantified. For many key seismic stations, detection lists may be dominated by signals from routine industrial explosions which should be ascribed, automatically and with a high level of confidence, to known sources. This means that expensive analyst time is not spent locating routine events from repeating seismic sources and that events from unknown sources, which could be of concern in an explosion monitoring context, are more easily identified and can be examined with due care. We have obtained extensive lists of confirmed seismic events from mining and other artificial sources which have provided an excellent opportunity to assess the quality of existing fully-automatic event bulletins and to guide the development of new techniques for online seismic processing. Comparing the times and locations of confirmed events from sources in Fennoscandia and NW Russia with the corresponding time and location estimates reported in existing automatic bulletins has revealed substantial mislocation errors which preclude a confident association of detected signals with known industrial sources. The causes of the errors are well understood and are

  6. Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

    International Nuclear Information System (INIS)

    Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

    2007-01-01

    In the field of nuclear explosion monitoring, it has become a priority to detect, locate, and identify seismic events down to increasingly small magnitudes. The consideration of smaller seismic events has implications for a reliable monitoring regime. Firstly, the number of events to be considered increases greatly; an exponential increase in naturally occurring seismicity is compounded by large numbers of seismic signals generated by human activity. Secondly, the signals from smaller events become more difficult to detect above the background noise and estimates of parameters required for locating the events may be subject to greater errors. Thirdly, events are likely to be observed by a far smaller number of seismic stations, and the reliability of event detection and location using a very limited set of observations needs to be quantified. For many key seismic stations, detection lists may be dominated by signals from routine industrial explosions which should be ascribed, automatically and with a high level of confidence, to known sources. This means that expensive analyst time is not spent locating routine events from repeating seismic sources and that events from unknown sources, which could be of concern in an explosion monitoring context, are more easily identified and can be examined with due care. We have obtained extensive lists of confirmed seismic events from mining and other artificial sources which have provided an excellent opportunity to assess the quality of existing fully-automatic event bulletins and to guide the development of new techniques for online seismic processing. Comparing the times and locations of confirmed events from sources in Fennoscandia and NW Russia with the corresponding time and location estimates reported in existing automatic bulletins has revealed substantial mislocation errors which preclude a confident association of detected signals with known industrial sources. The causes of the errors are well understood and are

  7. A Novel Event-Based Incipient Slip Detection Using Dynamic Active-Pixel Vision Sensor (DAVIS).

    Science.gov (United States)

    Rigi, Amin; Baghaei Naeini, Fariborz; Makris, Dimitrios; Zweiri, Yahya

    2018-01-24

    In this paper, a novel approach to detect incipient slip based on the contact area between a transparent silicone medium and different objects using a neuromorphic event-based vision sensor (DAVIS) is proposed. Event-based algorithms are developed to detect incipient slip, slip, stress distribution and object vibration. Thirty-seven experiments were performed on five objects with different sizes, shapes, materials and weights to compare precision and response time of the proposed approach. The proposed approach is validated by using a high speed constitutional camera (1000 FPS). The results indicate that the sensor can detect incipient slippage with an average of 44.1 ms latency in unstructured environment for various objects. It is worth mentioning that the experiments were conducted in an uncontrolled experimental environment, therefore adding high noise levels that affected results significantly. However, eleven of the experiments had a detection latency below 10 ms which shows the capability of this method. The results are very promising and show a high potential of the sensor being used for manipulation applications especially in dynamic environments.

  8. Event Detection Intelligent Camera: Demonstration of flexible, real-time data taking and processing

    Energy Technology Data Exchange (ETDEWEB)

    Szabolics, Tamás, E-mail: szabolics.tamas@wigner.mta.hu; Cseh, Gábor; Kocsis, Gábor; Szepesi, Tamás; Zoletnik, Sándor

    2015-10-15

    Highlights: • We present EDICAM's operation principles description. • Firmware tests results. • Software test results. • Further developments. - Abstract: An innovative fast camera (EDICAM – Event Detection Intelligent CAMera) was developed by MTA Wigner RCP in the last few years. This new concept was designed for intelligent event driven processing to be able to detect predefined events and track objects in the plasma. The camera provides a moderate frame rate of 400 Hz at full frame resolution (1280 × 1024), and readout of smaller region of interests can be done in the 1–140 kHz range even during exposure of the full image. One of the most important advantages of this hardware is a 10 Gbit/s optical link which ensures very fast communication and data transfer between the PC and the camera, enabling two level of processing: primitive algorithms in the camera hardware and high-level processing in the PC. This camera hardware has successfully proven to be able to monitoring the plasma in several fusion devices for example at ASDEX Upgrade, KSTAR and COMPASS with the first version of firmware. A new firmware and software package is under development. It allows to detect predefined events in real time and therefore the camera is capable to change its own operation or to give warnings e.g. to the safety system of the experiment. The EDICAM system can handle a huge amount of data (up to TBs) with high data rate (950 MB/s) and will be used as the central element of the 10 camera overview video diagnostic system of Wendenstein 7-X (W7-X) stellarator. This paper presents key elements of the newly developed built-in intelligence stressing the revolutionary new features and the results of the test of the different software elements.

  9. Automatic detection of lexical change: an auditory event-related potential study.

    Science.gov (United States)

    Muller-Gass, Alexandra; Roye, Anja; Kirmse, Ursula; Saupe, Katja; Jacobsen, Thomas; Schröger, Erich

    2007-10-29

    We investigated the detection of rare task-irrelevant changes in the lexical status of speech stimuli. Participants performed a nonlinguistic task on word and pseudoword stimuli that occurred, in separate conditions, rarely or frequently. Task performance for pseudowords was deteriorated relative to words, suggesting unintentional lexical analysis. Furthermore, rare word and pseudoword changes had a similar effect on the event-related potentials, starting as early as 165 ms. This is the first demonstration of the automatic detection of change in lexical status that is not based on a co-occurring acoustic change. We propose that, following lexical analysis of the incoming stimuli, a mental representation of the lexical regularity is formed and used as a template against which lexical change can be detected.

  10. High-Performance Signal Detection for Adverse Drug Events using MapReduce Paradigm.

    Science.gov (United States)

    Fan, Kai; Sun, Xingzhi; Tao, Ying; Xu, Linhao; Wang, Chen; Mao, Xianling; Peng, Bo; Pan, Yue

    2010-11-13

    Post-marketing pharmacovigilance is important for public health, as many Adverse Drug Events (ADEs) are unknown when those drugs were approved for marketing. However, due to the large number of reported drugs and drug combinations, detecting ADE signals by mining these reports is becoming a challenging task in terms of computational complexity. Recently, a parallel programming model, MapReduce has been introduced by Google to support large-scale data intensive applications. In this study, we proposed a MapReduce-based algorithm, for common ADE detection approach, Proportional Reporting Ratio (PRR), and tested it in mining spontaneous ADE reports from FDA. The purpose is to investigate the possibility of using MapReduce principle to speed up biomedical data mining tasks using this pharmacovigilance case as one specific example. The results demonstrated that MapReduce programming model could improve the performance of common signal detection algorithm for pharmacovigilance in a distributed computation environment at approximately liner speedup rates.

  11. EVENT DETECTION USING MOBILE PHONE MASS GPS DATA AND THEIR RELIAVILITY VERIFICATION BY DMSP/OLS NIGHT LIGHT IMAGE

    Directory of Open Access Journals (Sweden)

    A. Yuki

    2016-06-01

    Full Text Available In this study, we developed a method to detect sudden population concentration on a certain day and area, that is, an “Event,” all over Japan in 2012 using mass GPS data provided from mobile phone users. First, stay locations of all phone users were detected using existing methods. Second, areas and days where Events occurred were detected by aggregation of mass stay locations into 1-km-square grid polygons. Finally, the proposed method could detect Events with an especially large number of visitors in the year by removing the influences of Events that occurred continuously throughout the year. In addition, we demonstrated reasonable reliability of the proposed Event detection method by comparing the results of Event detection with light intensities obtained from the night light images from the DMSP/OLS night light images. Our method can detect not only positive events such as festivals but also negative events such as natural disasters and road accidents. These results are expected to support policy development of urban planning, disaster prevention, and transportation management.

  12. [Detection of adverse events in hospitalized adult patients by using the Global Trigger Tool method].

    Science.gov (United States)

    Guzmán-Ruiz, O; Ruiz-López, P; Gómez-Cámara, A; Ramírez-Martín, M

    2015-01-01

    To identify and characterize adverse events (AE) in an Internal Medicine Department of a district hospital using an extension of the Global Trigger Tool (GTT), analyzing the diagnostic validity of the tool. An observational, analytical, descriptive and retrospective study was conducted on 2013 clinical charts from an Internal Medicine Department in order to detect EA through the identification of 'triggers' (an event often related to an AE). The 'triggers' and AE were located by systematic review of clinical documentation. The AE were characterized after they were identified. A total of 149 AE were detected in 291 clinical charts during 2013, of which 75.3% were detected directly by the tool, while the rest were not associated with a trigger. The percentage of charts that had at least one AE was 35.4%. The most frequent AE found was pressure ulcer (12%), followed by delirium, constipation, nosocomial respiratory infection and altered level of consciousness by drugs. Almost half (47.6%) of the AE were related to drug use, and 32.2% of all AE were considered preventable. The tool demonstrated a sensitivity of 91.3% (95%CI: 88.9-93.2) and a specificity of 32.5% (95%CI: 29.9-35.1). It had a positive predictive value of 42.5% (95%CI: 40.1-45.1) and a negative predictive value of 87.1% (95%CI: 83.8-89.9). The tool used in this study is valid, useful and reproducible for the detection of AE. It also serves to determine rates of injury and to observe their progression over time. A high frequency of both AE and preventable events were observed in this study. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

  13. Predictive modeling of structured electronic health records for adverse drug event detection.

    Science.gov (United States)

    Zhao, Jing; Henriksson, Aron; Asker, Lars; Boström, Henrik

    2015-01-01

    The digitization of healthcare data, resulting from the increasingly widespread adoption of electronic health records, has greatly facilitated its analysis by computational methods and thereby enabled large-scale secondary use thereof. This can be exploited to support public health activities such as pharmacovigilance, wherein the safety of drugs is monitored to inform regulatory decisions about sustained use. To that end, electronic health records have emerged as a potentially valuable data source, providing access to longitudinal observations of patient treatment and drug use. A nascent line of research concerns predictive modeling of healthcare data for the automatic detection of adverse drug events, which presents its own set of challenges: it is not yet clear how to represent the heterogeneous data types in a manner conducive to learning high-performing machine learning models. Datasets from an electronic health record database are used for learning predictive models with the purpose of detecting adverse drug events. The use and representation of two data types, as well as their combination, are studied: clinical codes, describing prescribed drugs and assigned diagnoses, and measurements. Feature selection is conducted on the various types of data to reduce dimensionality and sparsity, while allowing for an in-depth feature analysis of the usefulness of each data type and representation. Within each data type, combining multiple representations yields better predictive performance compared to using any single representation. The use of clinical codes for adverse drug event detection significantly outperforms the use of measurements; however, there is no significant difference over datasets between using only clinical codes and their combination with measurements. For certain adverse drug events, the combination does, however, outperform using only clinical codes. Feature selection leads to increased predictive performance for both data types, in isolation and

  14. An Ensemble Approach for Emotion Cause Detection with Event Extraction and Multi-Kernel SVMs

    Institute of Scientific and Technical Information of China (English)

    Ruifeng Xu; Jiannan Hu; Qin Lu; Dongyin Wu; Lin Gui

    2017-01-01

    In this paper,we present a new challenging task for emotion analysis,namely emotion cause extraction.In this task,we focus on the detection of emotion cause a.k.a the reason or the stimulant of an emotion,rather than the regular emotion classification or emotion component extraction.Since there is no open dataset for this task available,we first designed and annotated an emotion cause dataset which follows the scheme of W3C Emotion Markup Language.We then present an emotion cause detection method by using event extraction framework,where a tree structure-based representation method is used to represent the events.Since the distribution of events is imbalanced in the training data,we propose an under-sampling-based bagging algorithm to solve this problem.Even with a limited training set,the proposed approach may still extract sufficient features for analysis by a bagging of multi-kernel based SVMs method.Evaluations show that our approach achieves an F-measure 7.04% higher than the state-of-the-art methods.

  15. Automatic Multi-sensor Data Quality Checking and Event Detection for Environmental Sensing

    Science.gov (United States)

    LIU, Q.; Zhang, Y.; Zhao, Y.; Gao, D.; Gallaher, D. W.; Lv, Q.; Shang, L.

    2017-12-01

    With the advances in sensing technologies, large-scale environmental sensing infrastructures are pervasively deployed to continuously collect data for various research and application fields, such as air quality study and weather condition monitoring. In such infrastructures, many sensor nodes are distributed in a specific area and each individual sensor node is capable of measuring several parameters (e.g., humidity, temperature, and pressure), providing massive data for natural event detection and analysis. However, due to the dynamics of the ambient environment, sensor data can be contaminated by errors or noise. Thus, data quality is still a primary concern for scientists before drawing any reliable scientific conclusions. To help researchers identify potential data quality issues and detect meaningful natural events, this work proposes a novel algorithm to automatically identify and rank anomalous time windows from multiple sensor data streams. More specifically, (1) the algorithm adaptively learns the characteristics of normal evolving time series and (2) models the spatial-temporal relationship among multiple sensor nodes to infer the anomaly likelihood of a time series window for a particular parameter in a sensor node. Case studies using different data sets are presented and the experimental results demonstrate that the proposed algorithm can effectively identify anomalous time windows, which may resulted from data quality issues and natural events.

  16. Vision-based Event Detection of the Sit-to-Stand Transition

    Directory of Open Access Journals (Sweden)

    Victor Shia

    2015-12-01

    Full Text Available Sit-to-stand (STS motions are one of the most important activities of daily living as they serve as a precursor to mobility and walking. However, there exist no standard method of segmenting STS motions. This is partially due to the variety of different sensors and modalities used to study the STS motion such as force plate, vision, and accelerometers, each providing different types of data, and the variability of the STS motion in video data. In this work, we present a method using motion capture to detect events in the STS motion by estimating ground reaction forces, thereby eliminating the variability in joint angles from visual data. We illustrate the accuracy of this method with 10 subjects with an average difference of 16.5ms in event times obtained via motion capture vs force plate. This method serves as a proof of concept for detecting events in the STS motion via video which are comparable to those obtained via force plate.

  17. Galactic synchrotron emission from WIMPs at radio frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, Istituto Nazionale di Fisica Nucleare, via P. Giuria 1, I-10125 Torino (Italy); Lineros, Roberto A.; Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@ific.uv.es [IFIC, CSIC-Universidad de Valencia, Ed. Institutos, Apdo. Correos 22085, E-46071 Valencia (Spain)

    2012-01-01

    Dark matter annihilations in the Galactic halo inject relativistic electrons and positrons which in turn generate a synchrotron radiation when interacting with the galactic magnetic field. We calculate the synchrotron flux for various dark matter annihilation channels, masses, and astrophysical assumptions in the low-frequency range and compare our results with radio surveys from 22 MHz to 1420 MHz. We find that current observations are able to constrain particle dark matter with ''thermal'' annihilation cross-sections, i.e. (σv) = 3 × 10{sup −26} cm{sup 3} s{sup −1}, and masses M{sub DM}∼<10 GeV. We discuss the dependence of these bounds on the astrophysical assumptions, namely galactic dark matter distribution, cosmic rays propagation parameters, and structure of the galactic magnetic field. Prospects for detection in future radio surveys are outlined.

  18. Galactic synchrotron emission from WIMPs at radio frequencies

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; Taoso, Marco

    2012-01-01

    Dark matter annihilations in the Galactic halo inject relativistic electrons and positrons which in turn generate a synchrotron radiation when interacting with the galactic magnetic field. We calculate the synchrotron flux for various dark matter annihilation channels, masses, and astrophysical assumptions in the low-frequency range and compare our results with radio surveys from 22 MHz to 1420 MHz. We find that current observations are able to constrain particle dark matter with ''thermal'' annihilation cross-sections, i.e. (σv) = 3 × 10 −26 cm 3 s −1 , and masses M DM ∼<10 GeV. We discuss the dependence of these bounds on the astrophysical assumptions, namely galactic dark matter distribution, cosmic rays propagation parameters, and structure of the galactic magnetic field. Prospects for detection in future radio surveys are outlined

  19. The necessity of recognizing all events in x-ray detection

    International Nuclear Information System (INIS)

    Papp, T.; Maxwell, J.A.; Papp, A.T.

    2008-01-01

    -ray detection. Examples will be given in detection of x-rays in nuclear backgrounds, and in industrial measurements for ROHS and WEEE compliance with input rates of up to several hundred thousands counts per seconds. The availability of all the events allows one to see the other part of the spectrum, and thus offer explanations why the basic parameters are in such a bad shape

  20. Detection of Visual Events in Underwater Video Using a Neuromorphic Saliency-based Attention System

    Science.gov (United States)

    Edgington, D. R.; Walther, D.; Cline, D. E.; Sherlock, R.; Salamy, K. A.; Wilson, A.; Koch, C.

    2003-12-01

    The Monterey Bay Aquarium Research Institute (MBARI) uses high-resolution video equipment on remotely operated vehicles (ROV) to obtain quantitative data on the distribution and abundance of oceanic animals. High-quality video data supplants the traditional approach of assessing the kinds and numbers of animals in the oceanic water column through towing collection nets behind ships. Tow nets are limited in spatial resolution, and often destroy abundant gelatinous animals resulting in species undersampling. Video camera-based quantitative video transects (QVT) are taken through the ocean midwater, from 50m to 4000m, and provide high-resolution data at the scale of the individual animals and their natural aggregation patterns. However, the current manual method of analyzing QVT video by trained scientists is labor intensive and poses a serious limitation to the amount of information that can be analyzed from ROV dives. Presented here is an automated system for detecting marine animals (events) visible in the videos. Automated detection is difficult due to the low contrast of many translucent animals and due to debris ("marine snow") cluttering the scene. Video frames are processed with an artificial intelligence attention selection algorithm that has proven a robust means of target detection in a variety of natural terrestrial scenes. The candidate locations identified by the attention selection module are tracked across video frames using linear Kalman filters. Typically, the occurrence of visible animals in the video footage is sparse in space and time. A notion of "boring" video frames is developed by detecting whether or not there is an interesting candidate object for an animal present in a particular sequence of underwater video -- video frames that do not contain any "interesting" events. If objects can be tracked successfully over several frames, they are stored as potentially "interesting" events. Based on low-level properties, interesting events are

  1. Performance Evaluation of Wireless Sensor Networks for Event-Detection with Shadowing-Induced Radio Irregularities

    Directory of Open Access Journals (Sweden)

    Giuseppe De Marco

    2007-01-01

    Full Text Available In this paper, we study a particular application of wireless sensor networks for event-detection and tracking. In this kind of application, the transport of data is simplified, and guaranteeing a minimum number of packets at the monitoring node is the only constraint on the performance of the sensor network. This minimum number of packets is called event-reliability. Contrary to other studies on the subject, here we consider the behavior of such a network in presence of a realistic radio model, such as the shadowing of the radio signal. With this setting, we extend our previous analysis of the event-reliability approach for the transport of data. In particular, both regular and random networks are considered. The contribute of this work is to show via simulations that, in the presence of randomness or irregularities in the radio channel, the event-reliability can be jeopardized, that is the constraint on the minimum number of packets at the sink node could not be satisfied.

  2. Rapid and reliable detection and identification of GM events using multiplex PCR coupled with oligonucleotide microarray.

    Science.gov (United States)

    Xu, Xiaodan; Li, Yingcong; Zhao, Heng; Wen, Si-yuan; Wang, Sheng-qi; Huang, Jian; Huang, Kun-lun; Luo, Yun-bo

    2005-05-18

    To devise a rapid and reliable method for the detection and identification of genetically modified (GM) events, we developed a multiplex polymerase chain reaction (PCR) coupled with a DNA microarray system simultaneously aiming at many targets in a single reaction. The system included probes for screening gene, species reference gene, specific gene, construct-specific gene, event-specific gene, and internal and negative control genes. 18S rRNA was combined with species reference genes as internal controls to assess the efficiency of all reactions and to eliminate false negatives. Two sets of the multiplex PCR system were used to amplify four and five targets, respectively. Eight different structure genes could be detected and identified simultaneously for Roundup Ready soybean in a single microarray. The microarray specificity was validated by its ability to discriminate two GM maizes Bt176 and Bt11. The advantages of this method are its high specificity and greatly reduced false-positives and -negatives. The multiplex PCR coupled with microarray technology presented here is a rapid and reliable tool for the simultaneous detection of GM organism ingredients.

  3. Femtomolar detection of single mismatches by discriminant analysis of DNA hybridization events using gold nanoparticles.

    Science.gov (United States)

    Ma, Xingyi; Sim, Sang Jun

    2013-03-21

    Even though DNA-based nanosensors have been demonstrated for quantitative detection of analytes and diseases, hybridization events have never been numerically investigated for further understanding of DNA mediated interactions. Here, we developed a nanoscale platform with well-designed capture and detection gold nanoprobes to precisely evaluate the hybridization events. The capture gold nanoprobes were mono-laid on glass and the detection probes were fabricated via a novel competitive conjugation method. The two kinds of probes combined in a suitable orientation following the hybridization with the target. We found that hybridization efficiency was markedly dependent on electrostatic interactions between DNA strands, which can be tailored by adjusting the salt concentration of the incubation solution. Due to the much lower stability of the double helix formed by mismatches, the hybridization efficiencies of single mismatched (MMT) and perfectly matched DNA (PMT) were different. Therefore, we obtained an optimized salt concentration that allowed for discrimination of MMT from PMT without stringent control of temperature or pH. The results indicated this to be an ultrasensitive and precise nanosensor for the diagnosis of genetic diseases.

  4. Detection of genetically modified maize events in Brazilian maize-derived food products

    Directory of Open Access Journals (Sweden)

    Maria Regina Branquinho

    2013-09-01

    Full Text Available The Brazilian government has approved many transgenic maize lines for commercialization and has established a threshold of 1% for food labeling, which underscores need for monitoring programs. Thirty four samples including flours and different types of nacho chips were analyzed by conventional and real-time PCR in 2011 and 2012. The events MON810, Bt11, and TC1507 were detected in most of the samples, and NK603 was present only in the samples analyzed in 2012. The authorized lines GA21, T25, and the unauthorized Bt176 were not detected. All positive samples in the qualitative tests collected in 2011 showed a transgenic content higher than 1%, and none of them was correctly labeled. Regarding the samples collected in 2012, all positive samples were quantified higher than the threshold, and 47.0% were not correctly labeled. The overall results indicated that the major genetically modified organisms detected were MON810, TC1507, Bt11, and NK603 events. Some industries that had failed to label their products in 2011 started labeling them in 2012, demonstrating compliance with the current legislation observing the consumer rights. Although these results are encouraging, it has been clearly demonstrated the need for continuous monitoring programs to ensure consumers that food products are labeled properly.

  5. Application of Data Cubes for Improving Detection of Water Cycle Extreme Events

    Science.gov (United States)

    Albayrak, Arif; Teng, William

    2015-01-01

    As part of an ongoing NASA-funded project to remove a longstanding barrier to accessing NASA data (i.e., accessing archived time-step array data as point-time series), for the hydrology and other point-time series-oriented communities, "data cubes" are created from which time series files (aka "data rods") are generated on-the-fly and made available as Web services from the Goddard Earth Sciences Data and Information Services Center (GES DISC). Data cubes are data as archived rearranged into spatio-temporal matrices, which allow for easy access to the data, both spatially and temporally. A data cube is a specific case of the general optimal strategy of reorganizing data to match the desired means of access. The gain from such reorganization is greater the larger the data set. As a use case of our project, we are leveraging existing software to explore the application of the data cubes concept to machine learning, for the purpose of detecting water cycle extreme events, a specific case of anomaly detection, requiring time series data. We investigate the use of support vector machines (SVM) for anomaly classification. We show an example of detection of water cycle extreme events, using data from the Tropical Rainfall Measuring Mission (TRMM).

  6. Very low frequency earthquakes (VLFEs) detected during episodic tremor and slip (ETS) events in Cascadia using a match filter method indicate repeating events

    Science.gov (United States)

    Hutchison, A. A.; Ghosh, A.

    2016-12-01

    Very low frequency earthquakes (VLFEs) occur in transitional zones of faults, releasing seismic energy in the 0.02-0.05 Hz frequency band over a 90 s duration and typically have magntitudes within the range of Mw 3.0-4.0. VLFEs can occur down-dip of the seismogenic zone, where they can transfer stress up-dip potentially bringing the locked zone closer to a critical failure stress. VLFEs also occur up-dip of the seismogenic zone in a region along the plate interface that can rupture coseismically during large megathrust events, such as the 2011 Tohoku-Oki earthquake [Ide et al., 2011]. VLFEs were first detected in Cascadia during the 2011 episodic tremor and slip (ETS) event, occurring coincidentally with tremor [Ghosh et al., 2015]. However, during the 2014 ETS event, VLFEs were spatially and temporally asynchronous with tremor activity [Hutchison and Ghosh, 2016]. Such contrasting behaviors remind us that the mechanics behind such events remain elusive, yet they are responsible for the largest portion of the moment release during an ETS event. Here, we apply a match filter method using known VLFEs as template events to detect additional VLFEs. Using a grid-search centroid moment tensor inversion method, we invert stacks of the resulting match filter detections to ensure moment tensor solutions are similar to that of the respective template events. Our ability to successfully employ a match filter method to VLFE detection in Cascadia intrinsically indicates that these events can be repeating, implying that the same asperities are likely responsible for generating multiple VLFEs.

  7. Further results on the WIMP annual modulation signature by DAMA/NaI

    International Nuclear Information System (INIS)

    Bernabei, R.; Belli, P.; Cappella, F.

    2005-01-01

    The ≅ 100 kg highly radiopure NaI(Tl) set-up of the DAMA project (DAMA/NaI) has investigated the model- independent WIMP annual modulation signature over seven annual cycles for a total exposure of 107731 kg x day, obtaining a model-independent evidence for the presence of a dark matter particle component in the galactic halo at 6.3 σ C.L.. Some of the many possible corollary model-dependent quests for the candidate particle have been investigated with the total exposure as well

  8. CPN/Tools: A Post-WIMP Interface for Editing and Simulating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Andersen, Peter; Beaudouin-Lafon, Michel; Mackay, Wendy E.

    2001-01-01

    traditional ideas about user interfaces, getting rid of pull-down menus, scrollbars, and even selection, while providing the same or greater functionality. It also uses the new and much faster CPN simulator and features incremental syntax checking of the nets. CPN/Tools requires an OpenGL graphics accelerator......CPN/Tools is a major redesign of the popular Design/CPN tool from the University of Aarhus CPN group. The new interface is based on advanced, post-WIMP interaction techniques, including bi-manual interaction, toolglasses and marking menus and a new metaphor for managing the workspace. It challenges...

  9. The use of twin-screen-based WIMPS in spacecraft control

    Science.gov (United States)

    Klim, R. D.

    1990-10-01

    The ergonomic problems of designing a sophisticated Windows Icons Mouse Pop-up (WIMP) based twin screen workstation are outlined. These same problems will be encountered by future spacecraft controllers. The design of a modern, advanced workstation for use on a distributed multicontrol center in a multisatellite control system is outlined. The system uses access control mechanisms to ensure that only authorized personnel can undertake certain operations on the workstation. Rules governing the use of windowing features, screen attributes, icons, keyboard and mouse in spacecraft control are discussed.

  10. Development of low-background CsI(Tl) crystals for WIMP search

    International Nuclear Information System (INIS)

    Lee, H.S.; Bhang, H.; Hahn, I.S.; Hwang, M.J.; Kim, H.J.; Kim, S.C.; Kim, S.K.; Kim, S.Y.; Kim, T.Y.; Kim, Y.D.; Kwak, J.W.; Kwon, Y.J.; Lee, J.; Lee, J.I.; Lee, M.J.; Li, J.; Myung, S.S.; Park, H.; Zhu, J.J.

    2007-01-01

    Search for weakly interacting massive particles (WIMPs) is being carried out at the underground laboratory, Yangyang, Korea. Characteristics and internal background of CsI(Tl) crystal have been investigated. In our extensive R and D, we reduced internal background in the CsI(Tl) crystal. With the latest, we have achieved 5.50+/-0.10cpd (counts/keV/kg/day) at 10-15keV low-energy region. Further reduction of internal background is foreseen with the CsI powder lately produced

  11. WIMP dark matter and supersymmetry searches with neutrino telescopes

    International Nuclear Information System (INIS)

    Fornengo, N.

    2011-01-01

    The particle physics interpretation of the missing-mass, or dark-matter, a problem of cosmological and astrophysical nature, is going to be placed under strong scrutiny in the next years. From the particle physics side, accelerator physics will deeply test theoretical ideas about new physics beyond the Standard Model, where a particle physics candidate to dark matter is often naturally obtained. From the astrophysical side, many probes are already providing a great deal of independent information on signals which can be produced by the galactic or extra-galactic dark matter. The current and new-generation experimental efforts are therefore going to place under deep scrutiny the theoretical explanations of the relevant signals. The ultimate hope is in fact to be able to disentangle a dark matter signal from the various sources of backgrounds. Neutrino telescopes are one of the prominent tools for looking at dark matter and search for a signal, the neutrino flux from Earth and Sun. In this neutrino dark matter searches share properties with both direct dark matter searches and cosmic-ray indirect dark matter searches, and therefore complement these different detection techniques.

  12. Hierarchical modeling for rare event detection and cell subset alignment across flow cytometry samples.

    Directory of Open Access Journals (Sweden)

    Andrew Cron

    Full Text Available Flow cytometry is the prototypical assay for multi-parameter single cell analysis, and is essential in vaccine and biomarker research for the enumeration of antigen-specific lymphocytes that are often found in extremely low frequencies (0.1% or less. Standard analysis of flow cytometry data relies on visual identification of cell subsets by experts, a process that is subjective and often difficult to reproduce. An alternative and more objective approach is the use of statistical models to identify cell subsets of interest in an automated fashion. Two specific challenges for automated analysis are to detect extremely low frequency event subsets without biasing the estimate by pre-processing enrichment, and the ability to align cell subsets across multiple data samples for comparative analysis. In this manuscript, we develop hierarchical modeling extensions to the Dirichlet Process Gaussian Mixture Model (DPGMM approach we have previously described for cell subset identification, and show that the hierarchical DPGMM (HDPGMM naturally generates an aligned data model that captures both commonalities and variations across multiple samples. HDPGMM also increases the sensitivity to extremely low frequency events by sharing information across multiple samples analyzed simultaneously. We validate the accuracy and reproducibility of HDPGMM estimates of antigen-specific T cells on clinically relevant reference peripheral blood mononuclear cell (PBMC samples with known frequencies of antigen-specific T cells. These cell samples take advantage of retrovirally TCR-transduced T cells spiked into autologous PBMC samples to give a defined number of antigen-specific T cells detectable by HLA-peptide multimer binding. We provide open source software that can take advantage of both multiple processors and GPU-acceleration to perform the numerically-demanding computations. We show that hierarchical modeling is a useful probabilistic approach that can provide a

  13. Signal Detection of Imipenem Compared to Other Drugs from Korea Adverse Event Reporting System Database.

    Science.gov (United States)

    Park, Kyounghoon; Soukavong, Mick; Kim, Jungmee; Kwon, Kyoung Eun; Jin, Xue Mei; Lee, Joongyub; Yang, Bo Ram; Park, Byung Joo

    2017-05-01

    To detect signals of adverse drug events after imipenem treatment using the Korea Institute of Drug Safety & Risk Management-Korea adverse event reporting system database (KIDS-KD). We performed data mining using KIDS-KD, which was constructed using spontaneously reported adverse event (AE) reports between December 1988 and June 2014. We detected signals calculated the proportional reporting ratio, reporting odds ratio, and information component of imipenem. We defined a signal as any AE that satisfied all three indices. The signals were compared with drug labels of nine countries. There were 807582 spontaneous AEs reports in the KIDS-KD. Among those, the number of antibiotics related AEs was 192510; 3382 reports were associated with imipenem. The most common imipenem-associated AE was the drug eruption; 353 times. We calculated the signal by comparing with all other antibiotics and drugs; 58 and 53 signals satisfied the three methods. We compared the drug labelling information of nine countries, including the USA, the UK, Japan, Italy, Switzerland, Germany, France, Canada, and South Korea, and discovered that the following signals were currently not included in drug labels: hypokalemia, cardiac arrest, cardiac failure, Parkinson's syndrome, myocardial infarction, and prostate enlargement. Hypokalemia was an additional signal compared with all other antibiotics, and the other signals were not different compared with all other antibiotics and all other drugs. We detected new signals that were not listed on the drug labels of nine countries. However, further pharmacoepidemiologic research is needed to evaluate the causality of these signals. © Copyright: Yonsei University College of Medicine 2017

  14. Quench detection of fast plasma events for the JT-60SA central solenoid

    International Nuclear Information System (INIS)

    Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Kamiya, Koji; Takahashi, Yoshikazu; Yoshida, Kiyoshi

    2012-01-01

    Highlights: ► Pick-up coil method is used for the quench detection of JT-60SA magnet system. ► Disk-shaped pick-up coils are inserted in CS module to compensate inductive voltage. ► Applicability of pick-up coil is evaluated by two dimensional analysis. ► Pick-up coil is applicable whenever disruption, mini collapse and other plasma event. - Abstract: The JT-60 is planned to be modified to a full-superconducting tokamak referred to as the JT-60 Super Advanced (JT-60SA). The maximum temperature of the magnet during its quench might reach the temperature of higher than several hundreds Kelvin that will damage the superconducting magnet itself. The high precision quench detection system, therefore, is one of the key technologies in the superconducting magnet protection system. The pick-up coil method, which is using voltage taps to detect the normal voltage, is used for the quench detection of the JT-60SA superconducting magnet system. The disk-shaped pick-up coils are inserted in the central solenoid (CS) module to compensate the inductive voltage. In the previous study, the quench detection system requires a large number of pick-up coils. The reliability of quench detection system would be higher by simplifying the detection system such as reducing the number of pick-up coils. Simplifying the quench detection system is also important to reduce the total cost of the protection system. Hence the design method is improved by increasing optimizing parameters. The improved design method can reduce the number of pick-up coils without reducing the sensitivity of detection; consequently the protection system can be designed with higher reliability and lower cost. The applicability of the disk-shaped pick-up coil for quench detection system is evaluated by the two dimensional analysis. In the previous study, however, the analysis model only took into account the CS, EF (equilibrium field) coils and plasma. Therefore, applicability of the disk-shaped pick-up coil for

  15. Analysis of arrhythmic events is useful to detect lead failure earlier in patients followed by remote monitoring.

    Science.gov (United States)

    Nishii, Nobuhiro; Miyoshi, Akihito; Kubo, Motoki; Miyamoto, Masakazu; Morimoto, Yoshimasa; Kawada, Satoshi; Nakagawa, Koji; Watanabe, Atsuyuki; Nakamura, Kazufumi; Morita, Hiroshi; Ito, Hiroshi

    2018-03-01

    Remote monitoring (RM) has been advocated as the new standard of care for patients with cardiovascular implantable electronic devices (CIEDs). RM has allowed the early detection of adverse clinical events, such as arrhythmia, lead failure, and battery depletion. However, lead failure was often identified only by arrhythmic events, but not impedance abnormalities. To compare the usefulness of arrhythmic events with conventional impedance abnormalities for identifying lead failure in CIED patients followed by RM. CIED patients in 12 hospitals have been followed by the RM center in Okayama University Hospital. All transmitted data have been analyzed and summarized. From April 2009 to March 2016, 1,873 patients have been followed by the RM center. During the mean follow-up period of 775 days, 42 lead failure events (atrial lead 22, right ventricular pacemaker lead 5, implantable cardioverter defibrillator [ICD] lead 15) were detected. The proportion of lead failures detected only by arrhythmic events, which were not detected by conventional impedance abnormalities, was significantly higher than that detected by impedance abnormalities (arrhythmic event 76.2%, 95% CI: 60.5-87.9%; impedance abnormalities 23.8%, 95% CI: 12.1-39.5%). Twenty-seven events (64.7%) were detected without any alert. Of 15 patients with ICD lead failure, none has experienced inappropriate therapy. RM can detect lead failure earlier, before clinical adverse events. However, CIEDs often diagnose lead failure as just arrhythmic events without any warning. Thus, to detect lead failure earlier, careful human analysis of arrhythmic events is useful. © 2017 Wiley Periodicals, Inc.

  16. An analog cell to detect single event transients in voltage references

    Energy Technology Data Exchange (ETDEWEB)

    Franco, F.J., E-mail: fjfranco@fis.ucm.es [Departamento de Física Aplicada III, Facultad de Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain); Palomar, C. [Departamento de Física Aplicada III, Facultad de Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain); Izquierdo, J.G. [Centro de Láseres Ultrarrápidos, Facultad de Químicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain); Agapito, J.A. [Departamento de Física Aplicada III, Facultad de Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain)

    2015-01-11

    A reliable voltage reference is mandatory in mixed-signal systems. However, this family of components can undergo very long single event transients when operating in radiation environments such as space and nuclear facilities due to the impact of heavy ions. The purpose of the present paper is to demonstrate how a simple cell can be used to detect these transients. The cell was implemented with typical COTS components and its behavior was verified by SPICE simulations and in a laser facility. Different applications of the cell are explored as well.

  17. Optimized Swinging Door Algorithm for Wind Power Ramp Event Detection: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Florita, Anthony R.; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2015-08-06

    Significant wind power ramp events (WPREs) are those that influence the integration of wind power, and they are a concern to the continued reliable operation of the power grid. As wind power penetration has increased in recent years, so has the importance of wind power ramps. In this paper, an optimized swinging door algorithm (SDA) is developed to improve ramp detection performance. Wind power time series data are segmented by the original SDA, and then all significant ramps are detected and merged through a dynamic programming algorithm. An application of the optimized SDA is provided to ascertain the optimal parameter of the original SDA. Measured wind power data from the Electric Reliability Council of Texas (ERCOT) are used to evaluate the proposed optimized SDA.

  18. Highly specific detection of genetic modification events using an enzyme-linked probe hybridization chip.

    Science.gov (United States)

    Zhang, M Z; Zhang, X F; Chen, X M; Chen, X; Wu, S; Xu, L L

    2015-08-10

    The enzyme-linked probe hybridization chip utilizes a method based on ligase-hybridizing probe chip technology, with the principle of using thio-primers for protection against enzyme digestion, and using lambda DNA exonuclease to cut multiple PCR products obtained from the sample being tested into single-strand chains for hybridization. The 5'-end amino-labeled probe was fixed onto the aldehyde chip, and hybridized with the single-stranded PCR product, followed by addition of a fluorescent-modified probe that was then enzymatically linked with the adjacent, substrate-bound probe in order to achieve highly specific, parallel, and high-throughput detection. Specificity and sensitivity testing demonstrated that enzyme-linked probe hybridization technology could be applied to the specific detection of eight genetic modification events at the same time, with a sensitivity reaching 0.1% and the achievement of accurate, efficient, and stable results.

  19. A power filter for the detection of burst events based on time-frequency spectrum estimation

    International Nuclear Information System (INIS)

    Guidi, G M; Cuoco, E; Vicere, A

    2004-01-01

    We propose as a statistic for the detection of bursts in a gravitational wave interferometer the 'energy' of the events estimated with a time-dependent calculation of the spectrum. This statistic has an asymptotic Gaussian distribution with known statistical moments, which makes it possible to perform a uniformly most powerful test (McDonough R N and Whalen A D 1995 Detection of Signals in Noise (New York: Academic)) on the energy mean. We estimate the receiver operating characteristic (ROC, from the same book) of this statistic for different levels of the signal-to-noise ratio in the specific case of a simulated noise having the spectral density expected for Virgo, using test signals taken from a library of possible waveforms emitted during the collapse of the core of type II supernovae

  20. Automatic detection of whole night snoring events using non-contact microphone.

    Directory of Open Access Journals (Sweden)

    Eliran Dafna

    Full Text Available OBJECTIVE: Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology. DESIGN: Sounds during polysomnography (PSG were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events. PATIENTS: Sixty-seven subjects (age 52.5 ± 13.5 years, BMI 30.8 ± 4.7 kg/m(2, m/f 40/27 referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects. MEASUREMENTS AND RESULTS: To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental. A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore and specificity of 98.3% (noise as noise. CONCLUSIONS: Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients.

  1. Detection of planets in extremely weak central perturbation microlensing events via next-generation ground-based surveys

    International Nuclear Information System (INIS)

    Chung, Sun-Ju; Lee, Chung-Uk; Koo, Jae-Rim

    2014-01-01

    Even though the recently discovered high-magnification event MOA-2010-BLG-311 had complete coverage over its peak, confident planet detection did not happen due to extremely weak central perturbations (EWCPs, fractional deviations of ≲ 2%). For confident detection of planets in EWCP events, it is necessary to have both high cadence monitoring and high photometric accuracy better than those of current follow-up observation systems. The next-generation ground-based observation project, Korea Microlensing Telescope Network (KMTNet), satisfies these conditions. We estimate the probability of occurrence of EWCP events with fractional deviations of ≤2% in high-magnification events and the efficiency of detecting planets in the EWCP events using the KMTNet. From this study, we find that the EWCP events occur with a frequency of >50% in the case of ≲ 100 M E planets with separations of 0.2 AU ≲ d ≲ 20 AU. We find that for main-sequence and sub-giant source stars, ≳ 1 M E planets in EWCP events with deviations ≤2% can be detected with frequency >50% in a certain range that changes with the planet mass. However, it is difficult to detect planets in EWCP events of bright stars like giant stars because it is easy for KMTNet to be saturated around the peak of the events because of its constant exposure time. EWCP events are caused by close, intermediate, and wide planetary systems with low-mass planets and close and wide planetary systems with massive planets. Therefore, we expect that a much greater variety of planetary systems than those already detected, which are mostly intermediate planetary systems, regardless of the planet mass, will be significantly detected in the near future.

  2. Detection of Water Contamination Events Using Fluorescence Spectroscopy and Alternating Trilinear Decomposition Algorithm

    Directory of Open Access Journals (Sweden)

    Jie Yu

    2017-01-01

    Full Text Available The method based on conventional index and UV-vision has been widely applied in the field of water quality abnormality detection. This paper presents a qualitative analysis approach to detect the water contamination events with unknown pollutants. Fluorescence spectra were used as water quality monitoring tools, and the detection method of unknown contaminants in water based on alternating trilinear decomposition (ATLD is proposed to analyze the excitation and emission spectra of the samples. The Delaunay triangulation interpolation method was used to make the pretreatment of three-dimensional fluorescence spectra data, in order to estimate the effect of Rayleigh and Raman scattering; ATLD model was applied to establish the model of normal water sample, and the residual matrix was obtained by subtracting the measured matrix from the model matrix; the residual sum of squares obtained from the residual matrix and threshold was used to make qualitative discrimination of test samples and distinguish drinking water samples and organic pollutant samples. The results of the study indicate that ATLD modeling with three-dimensional fluorescence spectra can provide a tool for detecting unknown organic pollutants in water qualitatively. The method based on fluorescence spectra can be complementary to the method based on conventional index and UV-vision.

  3. An Event-Triggered Machine Learning Approach for Accelerometer-Based Fall Detection.

    Science.gov (United States)

    Putra, I Putu Edy Suardiyana; Brusey, James; Gaura, Elena; Vesilo, Rein

    2017-12-22

    The fixed-size non-overlapping sliding window (FNSW) and fixed-size overlapping sliding window (FOSW) approaches are the most commonly used data-segmentation techniques in machine learning-based fall detection using accelerometer sensors. However, these techniques do not segment by fall stages (pre-impact, impact, and post-impact) and thus useful information is lost, which may reduce the detection rate of the classifier. Aligning the segment with the fall stage is difficult, as the segment size varies. We propose an event-triggered machine learning (EvenT-ML) approach that aligns each fall stage so that the characteristic features of the fall stages are more easily recognized. To evaluate our approach, two publicly accessible datasets were used. Classification and regression tree (CART), k -nearest neighbor ( k -NN), logistic regression (LR), and the support vector machine (SVM) were used to train the classifiers. EvenT-ML gives classifier F-scores of 98% for a chest-worn sensor and 92% for a waist-worn sensor, and significantly reduces the computational cost compared with the FNSW- and FOSW-based approaches, with reductions of up to 8-fold and 78-fold, respectively. EvenT-ML achieves a significantly better F-score than existing fall detection approaches. These results indicate that aligning feature segments with fall stages significantly increases the detection rate and reduces the computational cost.

  4. Endpoint visual detection of three genetically modified rice events by loop-mediated isothermal amplification.

    Science.gov (United States)

    Chen, Xiaoyun; Wang, Xiaofu; Jin, Nuo; Zhou, Yu; Huang, Sainan; Miao, Qingmei; Zhu, Qing; Xu, Junfeng

    2012-11-07

    Genetically modified (GM) rice KMD1, TT51-1, and KF6 are three of the most well known transgenic Bt rice lines in China. A rapid and sensitive molecular assay for risk assessment of GM rice is needed. Polymerase chain reaction (PCR), currently the most common method for detecting genetically modified organisms, requires temperature cycling and relatively complex procedures. Here we developed a visual and rapid loop-mediated isothermal amplification (LAMP) method to amplify three GM rice event-specific junction sequences. Target DNA was amplified and visualized by two indicators (SYBR green or hydroxy naphthol blue [HNB]) within 60 min at an isothermal temperature of 63 °C. Different kinds of plants were selected to ensure the specificity of detection and the results of the non-target samples were negative, indicating that the primer sets for the three GM rice varieties had good levels of specificity. The sensitivity of LAMP, with detection limits at low concentration levels (0.01%−0.005% GM), was 10- to 100-fold greater than that of conventional PCR. Additionally, the LAMP assay coupled with an indicator (SYBR green or HNB) facilitated analysis. These findings revealed that the rapid detection method was suitable as a simple field-based test to determine the status of GM crops.

  5. Development of electrochemical biosensor for detection of pathogenic microorganism in Asian dust events.

    Science.gov (United States)

    Yoo, Min-Sang; Shin, Minguk; Kim, Younghun; Jang, Min; Choi, Yoon-E; Park, Si Jae; Choi, Jonghoon; Lee, Jinyoung; Park, Chulhwan

    2017-05-01

    We developed a single-walled carbon nanotubes (SWCNTs)-based electrochemical biosensor for the detection of Bacillus subtilis, one of the microorganisms observed in Asian dust events, which causes respiratory diseases such as asthma and pneumonia. SWCNTs plays the role of a transducer in biological antigen/antibody reaction for the electrical signal while 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) and ant-B. subtilis were performed as a chemical linker and an acceptor, respectively, for the adhesion of target microorganism in the developed biosensor. The detection range (10 2 -10 10  CFU/mL) and the detection limit (10 2  CFU/mL) of the developed biosensor were identified while the response time was 10 min. The amount of target B. subtilis was the highest in the specificity test of the developed biosensor, compared with the other tested microorganisms (Staphylococcus aureus, Flavobacterium psychrolimnae, and Aquabacterium commune). In addition, target B. subtilis detected by the developed biosensor was observed by scanning electron microscope (SEM) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Endpoint Visual Detection of Three Genetically Modified Rice Events by Loop-Mediated Isothermal Amplification

    Directory of Open Access Journals (Sweden)

    Qing Zhu

    2012-11-01

    Full Text Available Genetically modified (GM rice KMD1, TT51-1, and KF6 are three of the most well known transgenic Bt rice lines in China. A rapid and sensitive molecular assay for risk assessment of GM rice is needed. Polymerase chain reaction (PCR, currently the most common method for detecting genetically modified organisms, requires temperature cycling and relatively complex procedures. Here we developed a visual and rapid loop-mediated isothermal amplification (LAMP method to amplify three GM rice event-specific junction sequences. Target DNA was amplified and visualized by two indicators (SYBR green or hydroxy naphthol blue [HNB] within 60 min at an isothermal temperature of 63 °C. Different kinds of plants were selected to ensure the specificity of detection and the results of the non-target samples were negative, indicating that the primer sets for the three GM rice varieties had good levels of specificity. The sensitivity of LAMP, with detection limits at low concentration levels (0.01%–0.005% GM, was 10- to 100-fold greater than that of conventional PCR. Additionally, the LAMP assay coupled with an indicator (SYBR green or HNB facilitated analysis. These findings revealed that the rapid detection method was suitable as a simple field-based test to determine the status of GM crops.

  7. A Cluster-Based Fuzzy Fusion Algorithm for Event Detection in Heterogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    ZiQi Hao

    2015-01-01

    Full Text Available As limited energy is one of the tough challenges in wireless sensor networks (WSN, energy saving becomes important in increasing the lifecycle of the network. Data fusion enables combining information from several sources thus to provide a unified scenario, which can significantly save sensor energy and enhance sensing data accuracy. In this paper, we propose a cluster-based data fusion algorithm for event detection. We use k-means algorithm to form the nodes into clusters, which can significantly reduce the energy consumption of intracluster communication. Distances between cluster heads and event and energy of clusters are fuzzified, thus to use a fuzzy logic to select the clusters that will participate in data uploading and fusion. Fuzzy logic method is also used by cluster heads for local decision, and then the local decision results are sent to the base station. Decision-level fusion for final decision of event is performed by base station according to the uploaded local decisions and fusion support degree of clusters calculated by fuzzy logic method. The effectiveness of this algorithm is demonstrated by simulation results.

  8. Online Least Squares One-Class Support Vector Machines-Based Abnormal Visual Event Detection

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2013-12-01

    Full Text Available The abnormal event detection problem is an important subject in real-time video surveillance. In this paper, we propose a novel online one-class classification algorithm, online least squares one-class support vector machine (online LS-OC-SVM, combined with its sparsified version (sparse online LS-OC-SVM. LS-OC-SVM extracts a hyperplane as an optimal description of training objects in a regularized least squares sense. The online LS-OC-SVM learns a training set with a limited number of samples to provide a basic normal model, then updates the model through remaining data. In the sparse online scheme, the model complexity is controlled by the coherence criterion. The online LS-OC-SVM is adopted to handle the abnormal event detection problem. Each frame of the video is characterized by the covariance matrix descriptor encoding the moving information, then is classified into a normal or an abnormal frame. Experiments are conducted, on a two-dimensional synthetic distribution dataset and a benchmark video surveillance dataset, to demonstrate the promising results of the proposed online LS-OC-SVM method.

  9. WIMP search in the mono-photon channel at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Habermehl, Moritz [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2016-07-01

    The International Linear Collider (ILC) is a planned electron-positron collider with √(s) tunable from 250 to 500 GeV, with a possible upgrade to 1 TeV. Besides precision measurements of the Higgs boson its physics goals comprise searches for physics beyond the Standard Model, e.g. searches for Dark Matter. This collider search assumes the production of WIMPs in pairs. They are not visible in the detector but the energy carried away can be observed via an additional (''tag'') particle. Photon emission from the initial state leads to the almost model independent signature: e{sup +}e{sup -} → χχγ. As this analysis tests couplings between WIMPs and leptons it is complementary to analogues searches at the LHC. A precise study is facilitated by the clean environment of lepton colliders with small systematics of electroweak backgrounds. While the conceptual feasibility and the sensitivity reach of the ILC have been shown in the past, this talk focusses on the consequences for the detector design. The requirements for the central detector as well as for the instrumentation of the forward region are discussed in the context of the ILD detector concept.

  10. Search for non-baryonic dark matter with cryogenic detectors based on ionisation and heat detection. Analysis of experimental data from the Edelweiss-I experiment

    International Nuclear Information System (INIS)

    Sanglard, V.

    2005-11-01

    The method of direct detection of WIMPs (weakly interactive massive particles) that are present in the halo of our galaxy rests on the detection of their interaction with a target nucleus. The Edelweiss experiment uses this technique with 3 cryogenic detectors operating on 2 modes ionization and heat. Each detector is made of a 320 g germanium crystal with 2 faces equipped with electrodes. In order to improve the collection of charges, an amorphous layer of Ge or Si is laid between the crystal surface and the electrodes. The validation of the detector system has been made with Co 57 and Cs 137 gamma sources and a Cf 252 neutron source. We present a comparison with simulation results and experimental data for the validation of the response to nuclear recoils. The whole experimental data collected by Edelweiss-I from 2000 till 2003 has been analysed. 40 events have been selected, 6 among them with an energy over 30 keV. Limits for the interaction cross-section between a WIMP and a nucleon have been deduced from the experimental data. The Yellin method has enabled us to determine a limit without knowing the background noise. The best sensitivity appears to be 1.5*10 -6 pb for a WIMP's mass of 80 GeV/c 2 and a confidence level of 90 per cent. In terms of events, the limit for an energy range of 30 - 100 keV is 0.12 events per kg and per day. (A.C.)

  11. Detecting regular sound changes in linguistics as events of concerted evolution.

    Science.gov (United States)

    Hruschka, Daniel J; Branford, Simon; Smith, Eric D; Wilkins, Jon; Meade, Andrew; Pagel, Mark; Bhattacharya, Tanmoy

    2015-01-05

    Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    O. Chavez

    2010-12-01

    Full Text Available The geomagnetic observatory of Juriquilla Mexico, located at longitude –100.45° and latitude 20.70°, and 1946 m a.s.l., has been operational since June 2004 compiling geomagnetic field measurements with a three component fluxgate magnetometer. In this paper, the results of the analysis of these measurements in relation to important seismic activity in the period of 2007 to 2009 are presented. For this purpose, we used superposed epochs of Discrete Wavelet Transform of filtered signals for the three components of the geomagnetic field during relative seismic calm, and it was compared with seismic events of magnitudes greater than Ms > 5.5, which have occurred in Mexico. The analysed epochs consisted of 18 h of observations for a dataset corresponding to 18 different earthquakes (EQs. The time series were processed for a period of 9 h prior to and 9 h after each seismic event. This data processing was compared with the same number of observations during a seismic calm. The proposed methodology proved to be an efficient tool to detect signals associated with seismic activity, especially when the seismic events occur in a distance (D from the observatory to the EQ, such that the ratio D/ρ < 1.8 where ρ is the earthquake radius preparation zone. The methodology presented herein shows important anomalies in the Ultra Low Frequency Range (ULF; 0.005–1 Hz, primarily for 0.25 to 0.5 Hz. Furthermore, the time variance (σ2 increases prior to, during and after the seismic event in relation to the coefficient D1 obtained, principally in the Bx (N-S and By (E-W geomagnetic components. Therefore, this paper proposes and develops a new methodology to extract the abnormal signals of the geomagnetic anomalies related to different stages of the EQs.

  13. Statistical improvement in detection level of gravitational microlensing events from their light curves

    Science.gov (United States)

    Ibrahim, Ichsan; Malasan, Hakim L.; Kunjaya, Chatief; Timur Jaelani, Anton; Puannandra Putri, Gerhana; Djamal, Mitra

    2018-04-01

    In astronomy, the brightness of a source is typically expressed in terms of magnitude. Conventionally, the magnitude is defined by the logarithm of received flux. This relationship is known as the Pogson formula. For received flux with a small signal to noise ratio (S/N), however, the formula gives a large magnitude error. We investigate whether the use of Inverse Hyperbolic Sine function (hereafter referred to as the Asinh magnitude) in the modified formulae could allow for an alternative calculation of magnitudes for small S/N flux, and whether the new approach is better for representing the brightness of that region. We study the possibility of increasing the detection level of gravitational microlensing using 40 selected microlensing light curves from the 2013 and 2014 seasons and by using the Asinh magnitude. Photometric data of the selected events are obtained from the Optical Gravitational Lensing Experiment (OGLE). We found that utilization of the Asinh magnitude makes the events brighter compared to using the logarithmic magnitude, with an average of about 3.42 × 10‑2 magnitude and an average in the difference of error between the logarithmic and the Asinh magnitude of about 2.21 × 10‑2 magnitude. The microlensing events OB140847 and OB140885 are found to have the largest difference values among the selected events. Using a Gaussian fit to find the peak for OB140847 and OB140885, we conclude statistically that the Asinh magnitude gives better mean squared values of the regression and narrower residual histograms than the Pogson magnitude. Based on these results, we also attempt to propose a limit in magnitude value for which use of the Asinh magnitude is optimal with small S/N data.

  14. Building a Global Catalog of Nonvolcanic Tremor Events Using an Automatic Detection Algorithm

    Science.gov (United States)

    Bagley, B. C.; Revenaugh, J.

    2009-12-01

    Nonvolcanic tremor is characterized by a long-period seismic event containing a series of low-frequency earthquakes (LFEs). Tremor has been detected in regions of subduction (e.g. Kao et. al. 2007, 2008; Shelly 2006) and beneath the San Andreas fault near Cholame, California (e.g. Nadeau and Dolenc, 2005). In some cases tremor events seem to have periodicity, and these are often referred to as episodic tremor and slip (ETS). The origin of nonvolcanic tremor has been ascribed to shear slip along plate boundaries and/or high pore-fluid pressure. The apparent periodicity and tectonic setting associated with ETS has led to the suggestion that there may be a link between ETS and megathrust earthquakes. Until recently tremor detection has been a manual process requiring visual inspection of seismic data. In areas that have dense seismic arrays (e.g. Japan) waveform cross correlation techniques have been successfully employed (e.g. Obara, 2002). Kao et al. (2007) developed an algorithm for automatic detection of seismic tremor that can be used in regions without dense arrays. This method has been used to create the Tremor Activity Monitoring System (TAMS), which is used by the Geologic Survey of Canada to monitor northern Cascadia. So far the study of nonvolcanic tremor has been limited to regions of subduction or along major transform faults. It is unknown if tremor events occur in other tectonic settings, or if the current detection schemes will be useful for finding them. We propose to look for tremor events in non-subduction regions. It is possible that if tremor exists in other regions it will have different characteristics and may not trigger the TAMS system or be amenable to other existing detection schemes. We are developing algorithms for searching sparse array data sets for quasi-harmonic energy bursts in hopes of recognizing and cataloging nonvolcanic tremor in an expanded tectonic setting. Statistical comparisons against the TAMS algorithm will be made if

  15. Single Versus Multiple Events Error Potential Detection in a BCI-Controlled Car Game With Continuous and Discrete Feedback.

    Science.gov (United States)

    Kreilinger, Alex; Hiebel, Hannah; Müller-Putz, Gernot R

    2016-03-01

    This work aimed to find and evaluate a new method for detecting errors in continuous brain-computer interface (BCI) applications. Instead of classifying errors on a single-trial basis, the new method was based on multiple events (MEs) analysis to increase the accuracy of error detection. In a BCI-driven car game, based on motor imagery (MI), discrete events were triggered whenever subjects collided with coins and/or barriers. Coins counted as correct events, whereas barriers were errors. This new method, termed ME method, combined and averaged the classification results of single events (SEs) and determined the correctness of MI trials, which consisted of event sequences instead of SEs. The benefit of this method was evaluated in an offline simulation. In an online experiment, the new method was used to detect erroneous MI trials. Such MI trials were discarded and could be repeated by the users. We found that, even with low SE error potential (ErrP) detection rates, feasible accuracies can be achieved when combining MEs to distinguish erroneous from correct MI trials. Online, all subjects reached higher scores with error detection than without, at the cost of longer times needed for completing the game. Findings suggest that ErrP detection may become a reliable tool for monitoring continuous states in BCI applications when combining MEs. This paper demonstrates a novel technique for detecting errors in online continuous BCI applications, which yields promising results even with low single-trial detection rates.

  16. Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo Tavares; Martinelli Filho, Martino, E-mail: martino@cardiol.br; Peixoto, Giselle de Lima; Lima, José Jayme Galvão de; Siqueira, Sérgio Freitas de; Costa, Roberto; Gowdak, Luís Henrique Wolff [Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP (Brazil); Paula, Flávio Jota de [Unidade de Transplante Renal - Divisão de Urologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP (Brazil); Kalil Filho, Roberto; Ramires, José Antônio Franchini [Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-11-15

    The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used. We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR). A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE. During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041). In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

  17. Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

    Directory of Open Access Journals (Sweden)

    Rodrigo Tavares Silva

    2015-11-01

    Full Text Available AbstractBackground:The recording of arrhythmic events (AE in renal transplant candidates (RTCs undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.Objective:We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR.Methods:A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.Results:During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002, and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001 were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041.Conclusions:In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

  18. Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

    Science.gov (United States)

    Silva, Rodrigo Tavares; Martinelli Filho, Martino; Peixoto, Giselle de Lima; de Lima, José Jayme Galvão; de Siqueira, Sérgio Freitas; Costa, Roberto; Gowdak, Luís Henrique Wolff; de Paula, Flávio Jota; Kalil Filho, Roberto; Ramires, José Antônio Franchini

    2015-01-01

    Background The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used. Objective We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR). Methods A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE. Results During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041). Conclusions In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT. PMID:26351983

  19. Towards Real-Time Detection of Gait Events on Different Terrains Using Time-Frequency Analysis and Peak Heuristics Algorithm.

    Science.gov (United States)

    Zhou, Hui; Ji, Ning; Samuel, Oluwarotimi Williams; Cao, Yafei; Zhao, Zheyi; Chen, Shixiong; Li, Guanglin

    2016-10-01

    Real-time detection of gait events can be applied as a reliable input to control drop foot correction devices and lower-limb prostheses. Among the different sensors used to acquire the signals associated with walking for gait event detection, the accelerometer is considered as a preferable sensor due to its convenience of use, small size, low cost, reliability, and low power consumption. Based on the acceleration signals, different algorithms have been proposed to detect toe off (TO) and heel strike (HS) gait events in previous studies. While these algorithms could achieve a relatively reasonable performance in gait event detection, they suffer from limitations such as poor real-time performance and are less reliable in the cases of up stair and down stair terrains. In this study, a new algorithm is proposed to detect the gait events on three walking terrains in real-time based on the analysis of acceleration jerk signals with a time-frequency method to obtain gait parameters, and then the determination of the peaks of jerk signals using peak heuristics. The performance of the newly proposed algorithm was evaluated with eight healthy subjects when they were walking on level ground, up stairs, and down stairs. Our experimental results showed that the mean F1 scores of the proposed algorithm were above 0.98 for HS event detection and 0.95 for TO event detection on the three terrains. This indicates that the current algorithm would be robust and accurate for gait event detection on different terrains. Findings from the current study suggest that the proposed method may be a preferable option in some applications such as drop foot correction devices and leg prostheses.

  20. Solar Power Ramp Events Detection Using an Optimized Swinging Door Algorithm: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Florita, Anthony; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2015-08-07

    Solar power ramp events (SPREs) are those that significantly influence the integration of solar power on non-clear days and threaten the reliable and economic operation of power systems. Accurately extracting solar power ramps becomes more important with increasing levels of solar power penetrations in power systems. In this paper, we develop an optimized swinging door algorithm (OpSDA) to detection. First, the swinging door algorithm (SDA) is utilized to segregate measured solar power generation into consecutive segments in a piecewise linear fashion. Then we use a dynamic programming approach to combine adjacent segments into significant ramps when the decision thresholds are met. In addition, the expected SPREs occurring in clear-sky solar power conditions are removed. Measured solar power data from Tucson Electric Power is used to assess the performance of the proposed methodology. OpSDA is compared to two other ramp detection methods: the SDA and the L1-Ramp Detect with Sliding Window (L1-SW) method. The statistical results show the validity and effectiveness of the proposed method. OpSDA can significantly improve the performance of the SDA, and it can perform as well as or better than L1-SW with substantially less computation time.

  1. Leveraging KVM Events to Detect Cache-Based Side Channel Attacks in a Virtualization Environment

    Directory of Open Access Journals (Sweden)

    Ady Wahyudi Paundu

    2018-01-01

    Full Text Available Cache-based side channel attack (CSCa techniques in virtualization systems are becoming more advanced, while defense methods against them are still perceived as nonpractical. The most recent CSCa variant called Flush + Flush has showed that the current detection methods can be easily bypassed. Within this work, we introduce a novel monitoring approach to detect CSCa operations inside a virtualization environment. We utilize the Kernel Virtual Machine (KVM event data in the kernel and process this data using a machine learning technique to identify any CSCa operation in the guest Virtual Machine (VM. We evaluate our approach using Receiver Operating Characteristic (ROC diagram of multiple attack and benign operation scenarios. Our method successfully separate the CSCa datasets from the non-CSCa datasets, on both trained and nontrained data scenarios. The successful classification also include the Flush + Flush attack scenario. We are also able to explain the classification results by extracting the set of most important features that separate both classes using their Fisher scores and show that our monitoring approach can work to detect CSCa in general. Finally, we evaluate the overhead impact of our CSCa monitoring method and show that it has a negligible computation overhead on the host and the guest VM.

  2. Review of nuclear power reactor coolant system leakage events and leak detection requirements

    International Nuclear Information System (INIS)

    Chokshi, N.C.; Srinivasan, M.; Kupperman, D.S.; Krishnaswamy, P.

    2005-01-01

    In response to the vessel head event at the Davis-Besse reactor, the U.S. Nuclear Regulatory Commission (NRC) formed a Lessons Learned Task Force (LLTF). Four action plans were formulated to respond to the recommendations of the LLTF. The action plans involved efforts on barrier integrity, stress corrosion cracking (SCC), operating experience, and inspection and program management. One part of the action plan on barrier integrity was an assessment to identify potential safety benefits from changes in requirements pertaining to leakage in the reactor coolant system (RCS). In this effort, experiments and models were reviewed to identify correlations between crack size, crack-tip-opening displacement (CTOD), and leak rate in the RCS. Sensitivity studies using the Seepage Quantification of Upsets In Reactor Tubes (SQUIRT) code were carried out to correlate crack parameters, such as crack size, with leak rate for various types of crack configurations in RCS components. A database that identifies the leakage source, leakage rate, and resulting actions from RCS leaks discovered in U.S. light water reactors was developed. Humidity monitoring systems for detecting leakage and acoustic emission crack monitoring systems for the detection of crack initiation and growth before a leak occurs were also considered. New approaches to the detection of a leak in the reactor head region by monitoring boric-acid aerosols were also considered. (authors)

  3. Ultra-Low Power Sensor System for Disaster Event Detection in Metro Tunnel Systems

    Directory of Open Access Journals (Sweden)

    Jonah VINCKE

    2017-05-01

    Full Text Available In this extended paper, the concept for an ultra-low power wireless sensor network (WSN for underground tunnel systems is presented highlighting the chosen sensors. Its objectives are the detection of emergency events either from natural disasters, such as flooding or fire, or from terrorist attacks using explosives. Earlier works have demonstrated that the power consumption for the communication can be reduced such that the data acquisition (i.e. sensor sub-system becomes the most significant energy consumer. By using ultra-low power components for the smoke detector, a hydrostatic pressure sensor for water ingress detection and a passive acoustic emission sensor for explosion detection, all considered threats are covered while the energy consumption can be kept very low in relation to the data acquisition. In addition to 1 the sensor system is integrated into a sensor board. The total average power consumption for operating the sensor sub-system is measured to be 35.9 µW for lower and 7.8 µW for upper nodes.

  4. Detecting Smoking Events Using Accelerometer Data Collected Via Smartwatch Technology: Validation Study.

    Science.gov (United States)

    Cole, Casey A; Anshari, Dien; Lambert, Victoria; Thrasher, James F; Valafar, Homayoun

    2017-12-13

    Smoking is the leading cause of preventable death in the world today. Ecological research on smoking in context currently relies on self-reported smoking behavior. Emerging smartwatch technology may more objectively measure smoking behavior by automatically detecting smoking sessions using robust machine learning models. This study aimed to examine the feasibility of detecting smoking behavior using smartwatches. The second aim of this study was to compare the success of observing smoking behavior with smartwatches to that of conventional self-reporting. A convenience sample of smokers was recruited for this study. Participants (N=10) recorded 12 hours of accelerometer data using a mobile phone and smartwatch. During these 12 hours, they engaged in various daily activities, including smoking, for which they logged the beginning and end of each smoking session. Raw data were classified as either smoking or nonsmoking using a machine learning model for pattern recognition. The accuracy of the model was evaluated by comparing the output with a detailed description of a modeled smoking session. In total, 120 hours of data were collected from participants and analyzed. The accuracy of self-reported smoking was approximately 78% (96/123). Our model was successful in detecting 100 of 123 (81%) smoking sessions recorded by participants. After eliminating sessions from the participants that did not adhere to study protocols, the true positive detection rate of the smartwatch based-detection increased to more than 90%. During the 120 hours of combined observation time, only 22 false positive smoking sessions were detected resulting in a 2.8% false positive rate. Smartwatch technology can provide an accurate, nonintrusive means of monitoring smoking behavior in natural contexts. The use of machine learning algorithms for passively detecting smoking sessions may enrich ecological momentary assessment protocols and cessation intervention studies that often rely on self

  5. Direct and Indirect Dark Matter Detection in Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Farinaldo [Federal Univ. of Paraba (Brazil)

    2013-01-01

    The Dark matter (DM) problem constitutes a key question at the interface among Particle Physics, Astrophysics and Cosmology. The observational data which have been accumulated in the last years point to an existence of non baryonic amount of DM. Since the Standard Model (SM) does not provide any candidate for such non-baryonic DM, the evidence of DM is a major indication for new physics beyond the SM. We will study in this work one of the most popular DM candidates, the so called WIMPs (Weakly Interacting Massive Particles) from a direct and indirect detection perspective. In order to approach the direct and indirect dection of DM in the context of Particle Physics in a more pedagogic way, we will begin our discussion talking about a minimal extension of the SM. Later we will work on the subject in a 3-3-1 model. Next, we will study the role of WIMPs in the Big Bang Nucleosynthesis. Lastly, we will look for indirect DM signals in the center of our galaxy using the NASA Satellite, called Fermi-LAT. Through a comprehensive analysis of the data events observed by Fermi-LAT and some background models, we will constrain the dark matter annihilation cross section for several annihilation channels and dark matter halo profiles.

  6. A Bio-Inspired Model-Based Approach for Context-Aware Post-WIMP Tele-Rehabilitation

    Directory of Open Access Journals (Sweden)

    Víctor López-Jaquero

    2016-10-01

    Full Text Available Tele-rehabilitation is one of the main domains where Information and Communication Technologies (ICT have been proven useful to move healthcare from care centers to patients’ home. Moreover, patients, especially those carrying out a physical therapy, cannot use a traditional Window, Icon, Menu, Pointer (WIMP system, but they need to interact in a natural way, that is, there is a need to move from WIMP systems to Post-WIMP ones. Moreover, tele-rehabilitation systems should be developed following the context-aware approach, so that they are able to adapt to the patients’ context to provide them with usable and effective therapies. In this work a model-based approach is presented to assist stakeholders in the development of context-aware Post-WIMP tele-rehabilitation systems. It entails three different models: (i a task model for designing the rehabilitation tasks; (ii a context model to facilitate the adaptation of these tasks to the context; and (iii a bio-inspired presentation model to specify thoroughly how such tasks should be performed by the patients. Our proposal overcomes one of the limitations of the model-based approach for the development of context-aware systems supporting the specification of non-functional requirements. Finally, a case study is used to illustrate how this proposal can be put into practice to design a real world rehabilitation task.

  7. First events from the CNGS neutrino beam detected in the OPERA experiment

    CERN Document Server

    Acquafredda, R.; Ambrosio, M.; Anokhina, A.; Aoki, S.; Ariga, A.; Arrabito, L.; Autiero, D.; Badertscher, A.; Bergnoli, A.; Bersani Greggio, F.; Besnier, M.; Beyer, M.; Bondil-Blin, S.; Borer, K.; Boucrot, J.; Boyarkin, V.; Bozza, C.; Brugnera, R.; Buontempo, S.; Caffari, Y.; Campagne, Jean-Eric; Carlus, B.; Carrara, E.; Cazes, A.; Chaussard, L.; Chernyavsky, M.; Chiarella, V.; Chon-Sen, N.; Chukanov, A.; Ciesielski, R.; Consiglio, L.; Cozzi, M.; Dal Corso, F.; D'Ambrosio, N.; Damet, J.; De Lellis, G.; Declais, Y.; Descombes, T.; De Serio, M.; Di Capua, F.; Di Ferdinando, D.; Di Giovanni, A.; Di Marco, N.; Di Troia, C.; Dmitrievski, S.; Dracos, M.; Duchesneau, D.; Dulach, B.; Dusini, S.; Ebert, J.; Enikeev, R.; Ereditato, A.; Esposito, L.S.; Fanin, C.; Favier, J.; Felici, G.; Ferber, T.; Fournier, L.; Franceschi, A.; Frekers, D.; Fukuda, T.; Fukushima, C.; Galkin, V.I.; Galkin, V.A.; Gallet, R.; Garfagnini, A.; Gaudiot, G.; Giacomelli, G.; Giarmana, O.; Giorgini, M.; Girard, L.; Girerd, C.; Goellnitz, C.; Goldberg, J.; Gornoushkin, Y.; Grella, G.; Grianti, F.; Guerin, C.; Guler, M.; Gustavino, C.; Hagner, C.; Hamane, T.; Hara, T.; Hauger, M.; Hess, M.; Hoshino, K.; Ieva, M.; Incurvati, M.; Jakovcic, K.; Janicsko Csathy, J.; Janutta, B.; Jollet, C.; Juget, F.; Kazuyama, M.; Kim, S.H.; Kimura, M.; Knuesel, J.; Kodama, K.; Kolev, D.; Komatsu, M.; Kose, U.; Krasnoperov, A.; Kreslo, I.; Krumstein, Z.; Laktineh, I.; de La Taille, C.; Le Flour, T.; Lieunard, S.; Ljubicic, A.; Longhin, A.; Malgin, A.; Manai, K.; Mandrioli, G.; Mantello, U.; Marotta, A.; Marteau, J.; Martin-Chassard, G.; Matveev, V.; Messina, M.; Meyer, L.; Micanovic, S.; Migliozzi, P.; Miyamoto, S.; Monacelli, Piero; Monteiro, I.; Morishima, K.; Moser, U.; Muciaccia, M.T.; Mugnier, P.; Naganawa, N.; Nakamura, M.; Nakano, T.; Napolitano, T.; Natsume, M.; Niwa, K.; Nonoyama, Y.; Nozdrin, A.; Ogawa, S.; Olchevski, A.; Orlandi, D.; Ossetski, D.; Paoloni, A.; Park, B.D.; Park, I.G.; Pastore, A.; Patrizii, L.; Pellegrino, L.; Pessard, H.; Pilipenko, V.; Pistillo, C.; Polukhina, N.; Pozzato, M.; Pretzl, K.; Publichenko, P.; Raux, L.; Repellin, J.P.; Roganova, T.; Romano, G.; Rosa, G.; Rubbia, A.; Ryasny, V.; Ryazhskaya, O.; Ryzhikov, D.; Sadovski, A.; Sanelli, C.; Sato, O.; Sato, Y.; Saveliev, V.; Savvinov, N.; Sazhina, G.; Schembri, A.; Schmidt Parzefall, W.; Schroeder, H.; Schutz, H.U.; Scotto Lavina, L.; Sewing, J.; Shibuya, H.; Simone, S.; Sioli, M.; Sirignano, C.; Sirri, G.; Song, J.S.; Spaeti, R.; Spinetti, M.; Stanco, L.; Starkov, N.; Stipcevic, M.; Strolin, Paolo Emilio; Sugonyaev, V.; Takahashi, S.; Tereschenko, V.; Terranova, F.; Tezuka, I.; Tioukov, V.; Tikhomirov, I.; Tolun, P.; Toshito, T.; Tsarev, V.; Tsenov, R.; Ugolino, U.; Ushida, N.; Van Beek, G.; Verguilov, V.; Vilain, P.; Votano, L.; Vuilleumier, J.L.; Waelchli, T.; Waldi, R.; Weber, M.; Wilquet, G.; Wonsak, B.; Wurth, R.; Wurtz, J.; Yakushev, V.; Yoon, C.S.; Zaitsev, Y.; Zamboni, I.; Zimmerman, R.

    2006-01-01

    The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode, through the study of nu_mu to nu_tau oscillations. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors. It is placed in the high-energy, long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. In August 2006 a first run with CNGS neutrinos was successfully conducted. A first sample of neutrino events was collected, statistically consistent with the integrated beam intensity. After a brief description of the beam and of the various sub-detectors, we report on the achievement of this milestone, presenting the first data and some analysis results.

  8. The Event Detection and the Apparent Velocity Estimation Based on Computer Vision

    Science.gov (United States)

    Shimojo, M.

    2012-08-01

    The high spatial and time resolution data obtained by the telescopes aboard Hinode revealed the new interesting dynamics in solar atmosphere. In order to detect such events and estimate the velocity of dynamics automatically, we examined the estimation methods of the optical flow based on the OpenCV that is the computer vision library. We applied the methods to the prominence eruption observed by NoRH, and the polar X-ray jet observed by XRT. As a result, it is clear that the methods work well for solar images if the images are optimized for the methods. It indicates that the optical flow estimation methods in the OpenCV library are very useful to analyze the solar phenomena.

  9. Detection of Cardiopulmonary Activity and Related Abnormal Events Using Microsoft Kinect Sensor.

    Science.gov (United States)

    Al-Naji, Ali; Chahl, Javaan

    2018-03-20

    Monitoring of cardiopulmonary activity is a challenge when attempted under adverse conditions, including different sleeping postures, environmental settings, and an unclear region of interest (ROI). This study proposes an efficient remote imaging system based on a Microsoft Kinect v2 sensor for the observation of cardiopulmonary-signal-and-detection-related abnormal cardiopulmonary events (e.g., tachycardia, bradycardia, tachypnea, bradypnea, and central apnoea) in many possible sleeping postures within varying environmental settings including in total darkness and whether the subject is covered by a blanket or not. The proposed system extracts the signal from the abdominal-thoracic region where cardiopulmonary activity is most pronounced, using a real-time image sequence captured by Kinect v2 sensor. The proposed system shows promising results in any sleep posture, regardless of illumination conditions and unclear ROI even in the presence of a blanket, whilst being reliable, safe, and cost-effective.

  10. Event detection and localization for small mobile robots using reservoir computing.

    Science.gov (United States)

    Antonelo, E A; Schrauwen, B; Stroobandt, D

    2008-08-01

    Reservoir Computing (RC) techniques use a fixed (usually randomly created) recurrent neural network, or more generally any dynamic system, which operates at the edge of stability, where only a linear static readout output layer is trained by standard linear regression methods. In this work, RC is used for detecting complex events in autonomous robot navigation. This can be extended to robot localization tasks which are solely based on a few low-range, high-noise sensory data. The robot thus builds an implicit map of the environment (after learning) that is used for efficient localization by simply processing the input stream of distance sensors. These techniques are demonstrated in both a simple simulation environment and in the physically realistic Webots simulation of the commercially available e-puck robot, using several complex and even dynamic environments.

  11. Decision support methods for the detection of adverse events in post-marketing data.

    Science.gov (United States)

    Hauben, M; Bate, A

    2009-04-01

    Spontaneous reporting is a crucial component of post-marketing drug safety surveillance despite its significant limitations. The size and complexity of some spontaneous reporting system databases represent a challenge for drug safety professionals who traditionally have relied heavily on the scientific and clinical acumen of the prepared mind. Computer algorithms that calculate statistical measures of reporting frequency for huge numbers of drug-event combinations are increasingly used to support pharamcovigilance analysts screening large spontaneous reporting system databases. After an overview of pharmacovigilance and spontaneous reporting systems, we discuss the theory and application of contemporary computer algorithms in regular use, those under development, and the practical considerations involved in the implementation of computer algorithms within a comprehensive and holistic drug safety signal detection program.

  12. Detection of Cardiopulmonary Activity and Related Abnormal Events Using Microsoft Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Ali Al-Naji

    2018-03-01

    Full Text Available Monitoring of cardiopulmonary activity is a challenge when attempted under adverse conditions, including different sleeping postures, environmental settings, and an unclear region of interest (ROI. This study proposes an efficient remote imaging system based on a Microsoft Kinect v2 sensor for the observation of cardiopulmonary-signal-and-detection-related abnormal cardiopulmonary events (e.g., tachycardia, bradycardia, tachypnea, bradypnea, and central apnoea in many possible sleeping postures within varying environmental settings including in total darkness and whether the subject is covered by a blanket or not. The proposed system extracts the signal from the abdominal-thoracic region where cardiopulmonary activity is most pronounced, using a real-time image sequence captured by Kinect v2 sensor. The proposed system shows promising results in any sleep posture, regardless of illumination conditions and unclear ROI even in the presence of a blanket, whilst being reliable, safe, and cost-effective.

  13. Standard and Nonstandard Neutrino-Nucleus Reactions Cross Sections and Event Rates to Neutrino Detection Experiments

    Directory of Open Access Journals (Sweden)

    D. K. Papoulias

    2015-01-01

    Full Text Available In this work, we explore ν-nucleus processes from a nuclear theory point of view and obtain results with high confidence level based on accurate nuclear structure cross sections calculations. Besides cross sections, the present study includes simulated signals expected to be recorded by nuclear detectors and differential event rates as well as total number of events predicted to be measured. Our original cross sections calculations are focused on measurable rates for the standard model process, but we also perform calculations for various channels of the nonstandard neutrino-nucleus reactions and come out with promising results within the current upper limits of the corresponding exotic parameters. We concentrate on the possibility of detecting (i supernova neutrinos by using massive detectors like those of the GERDA and SuperCDMS dark matter experiments and (ii laboratory neutrinos produced near the spallation neutron source facilities (at Oak Ridge National Lab by the COHERENT experiment. Our nuclear calculations take advantage of the relevant experimental sensitivity and employ the severe bounds extracted for the exotic parameters entering the Lagrangians of various particle physics models and specifically those resulting from the charged lepton flavour violating μ-→e- experiments (Mu2e and COMET experiments.

  14. Energy efficient data representation and aggregation with event region detection in wireless sensor networks

    Science.gov (United States)

    Banerjee, Torsha

    Detection (PERD) for WSNs. When a single event occurs, a child of the tree sends a Flagged Polynomial (FP) to its parent, if the readings approximated by it falls outside the data range defining the existing phenomenon. After the aggregation process is over, the root having the two polynomials, P and FP can be queried for FP (approximating the new event region) instead of flooding the whole network. For multiple such events, instead of computing a polynomial corresponding to each new event, areas with same data range are combined by the corresponding tree nodes and the aggregated coefficients are passed on. Results reveal that a new event can be detected by PERD while error in detection remains constant and is less than a threshold of 10%. As the node density increases, accuracy and delay for event detection are found to remain almost constant, making PERD highly scalable. Whenever an event occurs in a WSN, data is generated by closeby sensors and relaying the data to the base station (BS) make sensors closer to the BS run out of energy at a much faster rate than sensors in other parts of the network. This gives rise to an unequal distribution of residual energy in the network and makes those sensors with lower remaining energy level die at much faster rate than others. We propose a scheme for enhancing network Lifetime using mobile cluster heads (CH) in a WSN. To maintain remaining energy more evenly, some energy-rich nodes are designated as CHs which move in a controlled manner towards sensors rich in energy and data. This eliminates multihop transmission required by the static sensors and thus increases the overall lifetime of the WSN. We combine the idea of clustering and mobile CH to first form clusters of static sensor nodes. A collaborative strategy among the CHs further increases the lifetime of the network. Time taken for transmitting data to the BS is reduced further by making the CHs follow a connectivity strategy that always maintain a connected path to the BS

  15. Convolutional neural networks for event-related potential detection: impact of the architecture.

    Science.gov (United States)

    Cecotti, H

    2017-07-01

    The detection of brain responses at the single-trial level in the electroencephalogram (EEG) such as event-related potentials (ERPs) is a difficult problem that requires different processing steps to extract relevant discriminant features. While most of the signal and classification techniques for the detection of brain responses are based on linear algebra, different pattern recognition techniques such as convolutional neural network (CNN), as a type of deep learning technique, have shown some interests as they are able to process the signal after limited pre-processing. In this study, we propose to investigate the performance of CNNs in relation of their architecture and in relation to how they are evaluated: a single system for each subject, or a system for all the subjects. More particularly, we want to address the change of performance that can be observed between specifying a neural network to a subject, or by considering a neural network for a group of subjects, taking advantage of a larger number of trials from different subjects. The results support the conclusion that a convolutional neural network trained on different subjects can lead to an AUC above 0.9 by using an appropriate architecture using spatial filtering and shift invariant layers.

  16. Acoustic Event Detection in Multichannel Audio Using Gated Recurrent Neural Networks with High‐Resolution Spectral Features

    Directory of Open Access Journals (Sweden)

    Hyoung‐Gook Kim

    2017-12-01

    Full Text Available Recently, deep recurrent neural networks have achieved great success in various machine learning tasks, and have also been applied for sound event detection. The detection of temporally overlapping sound events in realistic environments is much more challenging than in monophonic detection problems. In this paper, we present an approach to improve the accuracy of polyphonic sound event detection in multichannel audio based on gated recurrent neural networks in combination with auditory spectral features. In the proposed method, human hearing perception‐based spatial and spectral‐domain noise‐reduced harmonic features are extracted from multichannel audio and used as high‐resolution spectral inputs to train gated recurrent neural networks. This provides a fast and stable convergence rate compared to long short‐term memory recurrent neural networks. Our evaluation reveals that the proposed method outperforms the conventional approaches.

  17. Detecting Forest Disturbance Events from MODIS and Landsat Time Series for the Conterminous United States

    Science.gov (United States)

    Zhang, G.; Ganguly, S.; Saatchi, S. S.; Hagen, S. C.; Harris, N.; Yu, Y.; Nemani, R. R.

    2013-12-01

    Spatial and temporal patterns of forest disturbance and regrowth processes are key for understanding aboveground terrestrial vegetation biomass and carbon stocks at regional-to-continental scales. The NASA Carbon Monitoring System (CMS) program seeks key input datasets, especially information related to impacts due to natural/man-made disturbances in forested landscapes of Conterminous U.S. (CONUS), that would reduce uncertainties in current carbon stock estimation and emission models. This study provides a end-to-end forest disturbance detection framework based on pixel time series analysis from MODIS (Moderate Resolution Imaging Spectroradiometer) and Landsat surface spectral reflectance data. We applied the BFAST (Breaks for Additive Seasonal and Trend) algorithm to the Normalized Difference Vegetation Index (NDVI) data for the time period from 2000 to 2011. A harmonic seasonal model was implemented in BFAST to decompose the time series to seasonal and interannual trend components in order to detect abrupt changes in magnitude and direction of these components. To apply the BFAST for whole CONUS, we built a parallel computing setup for processing massive time-series data using the high performance computing facility of the NASA Earth Exchange (NEX). In the implementation process, we extracted the dominant deforestation events from the magnitude of abrupt changes in both seasonal and interannual components, and estimated dates for corresponding deforestation events. We estimated the recovery rate for deforested regions through regression models developed between NDVI values and time since disturbance for all pixels. A similar implementation of the BFAST algorithm was performed over selected Landsat scenes (all Landsat cloud free data was used to generate NDVI from atmospherically corrected spectral reflectances) to demonstrate the spatial coherence in retrieval layers between MODIS and Landsat. In future, the application of this largely parallel disturbance

  18. Complementarity of WIMP Sensitivity with direct SUSY, Monojet and Dark Matter Searches in the MSSM

    CERN Document Server

    Arbey, Alexandre; Mahmoudi, Farvah

    2014-01-01

    This letter presents new results on the combined sensitivity of the LHC and underground dark matter search experiments to the lightest neutralino as WIMP candidate in the minimal Supersymmetric extension of the Standard Model. We show that monojet searches significantly extend the sensitivity to the neutralino mass in scenarios where scalar quarks are nearly degenerate in mass with it. The inclusion of the latest bound by the LUX experiment on the neutralino-nucleon spin-independent scattering cross section expands this sensitivity further, highlighting the remarkable complementarity of jets/$\\ell$s+MET and monojet at LHC and dark matter searches in probing models of new physics with a dark matter candidate. The qualitative results of our study remain valid after accounting for theoretical uncertainties.

  19. The power to detect recent fragmentation events using genetic differentiation methods.

    Directory of Open Access Journals (Sweden)

    Michael W Lloyd

    Full Text Available Habitat loss and fragmentation are imminent threats to biological diversity worldwide and thus are fundamental issues in conservation biology. Increased isolation alone has been implicated as a driver of negative impacts in populations associated with fragmented landscapes. Genetic monitoring and the use of measures of genetic divergence have been proposed as means to detect changes in landscape connectivity. Our goal was to evaluate the sensitivity of Wright's F st, Hedrick' G'st , Sherwin's MI, and Jost's D to recent fragmentation events across a range of population sizes and sampling regimes. We constructed an individual-based model, which used a factorial design to compare effects of varying population size, presence or absence of overlapping generations, and presence or absence of population sub-structuring. Increases in population size, overlapping generations, and population sub-structuring each reduced F st, G'st , MI, and D. The signal of fragmentation was detected within two generations for all metrics. However, the magnitude of the change in each was small in all cases, and when N e was >100 individuals it was extremely small. Multi-generational sampling and population estimates are required to differentiate the signal of background divergence from changes in Fst , G'st , MI, and D associated with fragmentation. Finally, the window during which rapid change in Fst , G'st , MI, and D between generations occurs can be small, and if missed would lead to inconclusive results. For these reasons, use of F st, G'st , MI, or D for detecting and monitoring changes in connectivity is likely to prove difficult in real-world scenarios. We advocate use of genetic monitoring only in conjunction with estimates of actual movement among patches such that one could compare current movement with the genetic signature of past movement to determine there has been a change.

  20. Detection of adverse events in general surgery using the " Trigger Tool" methodology.

    Science.gov (United States)

    Pérez Zapata, Ana Isabel; Gutiérrez Samaniego, María; Rodríguez Cuéllar, Elías; Andrés Esteban, Eva María; Gómez de la Cámara, Agustín; Ruiz López, Pedro

    2015-02-01

    Surgery is one of the high-risk areas for the occurrence of adverse events (AE). The purpose of this study is to know the percentage of hospitalisation-related AE that are detected by the «Global Trigger Tool» methodology in surgical patients, their characteristics and the tool validity. Retrospective, observational study on patients admitted to a general surgery department, who underwent a surgical operation in a third level hospital during the year 2012. The identification of AE was carried out by patient record review using an adaptation of «Global Trigger Tool» methodology. Once an AE was identified, a harm category was assigned, including the grade in which the AE could have been avoided and its relation with the surgical procedure. The prevalence of AE was 36,8%. There were 0,5 AE per patient. 56,2% were deemed preventable. 69,3% were directly related to the surgical procedure. The tool had a sensitivity of 86% and a specificity of 93,6%. The positive predictive value was 89% and the negative predictive value 92%. Prevalence of AE is greater than the estimate of other studies. In most cases the AE detected were related to the surgical procedure and more than half were also preventable. The adapted «Global Trigger Tool» methodology has demonstrated to be highly effective and efficient for detecting AE in surgical patients, identifying all the serious AE with few false negative results. Copyright © 2014 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Bioluminescence Detection of Cells Having Stabilized p53 in Response to a Genotoxic Event

    Directory of Open Access Journals (Sweden)

    Alnawaz Rehemtulla

    2004-01-01

    Full Text Available Inactivation of p53 is one of the most frequent molecular events in neoplastic transformation. Approximately 60% of all human tumors have mutations in both p53 alleles. Wild-type p53 activity is regulated in large part by the proteosome-dependent degradation of p53, resulting in a short p53 half-life in unstressed and untransformed cells. Activation of p53 by a variety of stimuli, including DNA damage induced by genotoxic drugs or radiation, is accomplished by stabilization of wild-type p53. The stabilized and active p53 can result in either cell-cycle arrest or apoptosis. Surprisingly, the majority of tumor-associated, inactivating p53 mutations also result in p53 accumulation. Thus, constitutive elevation of p53 levels in cells is a reliable measure of p53 inactivation, whereas transiently increased p53 levels reflect a recent genotoxic stress. In order to facilitate noninvasive imaging of p53 accumulation, we here describe the construction of a p53-luciferase fusion protein. Induction of DNA damage in cells expressing the fusion protein resulted in a time-dependent accumulation of the fusion that was noninvasively detected using bioluminescence imaging and validated by Western blot analysis. The p53-Luc protein retains p53 function because its expression in HCT116 cells lacking functional p53 resulted in activation of p21 expression as well as induction of apoptosis in response to a DNA damaging event. Employed in a transgenic animal model, the proposed p53-reporter fusion protein will be useful for studying p53 activation in response to exposure to DNA-damaging carcinogenic agents. It could also be used to study p53 stabilization as a result of inactivating p53 mutations. Such studies will further our understanding of p53's role as the “guardian of the genome” and its function in tumorigenesis.

  2. Detection of microsleep events in a car driving simulation study using electrocardiographic features

    Directory of Open Access Journals (Sweden)

    Lenis Gustavo

    2016-09-01

    Full Text Available Microsleep events (MSE are short intrusions of sleep under the demand of sustained attention. They can impose a major threat to safety while driving a car and are considered one of the most significant causes of traffic accidents. Driver’s fatigue and MSE account for up to 20% of all car crashes in Europe and at least 100,000 accidents in the US every year. Unfortunately, there is not a standardized test developed to quantify the degree of vigilance of a driver. To account for this problem, different approaches based on biosignal analysis have been studied in the past. In this paper, we investigate an electrocardiographic-based detection of MSE using morphological and rhythmical features. 14 records from a car driving simulation study with a high incidence of MSE were analyzed and the behavior of the ECG features before and after an MSE in relation to reference baseline values (without drowsiness were investigated. The results show that MSE cannot be detected (or predicted using only the ECG. However, in the presence of MSE, the rhythmical and morphological features were observed to be significantly different than the ones calculated for the reference signal without sleepiness. In particular, when MSE were present, the heart rate diminished while the heart rate variability increased. Time distances between P wave and R peak, and R peak and T wave and their dispersion increased also. This demonstrates a noticeable change of the autonomous regulation of the heart. In future, the ECG parameter could be used as a surrogate measure of fatigue.

  3. Detecting Micro-seismicity and Long-duration Tremor-like Events from the Oklahoma Wavefield Experiment

    Science.gov (United States)

    Li, C.; Li, Z.; Peng, Z.; Zhang, C.; Nakata, N.

    2017-12-01

    Oklahoma has experienced abrupt increase of induced seismicity in the last decade. An important way to fully understand seismic activities in Oklahoma is to obtain more complete earthquake catalogs and detect different types of seismic events. The IRIS Community Wavefield Demonstration Experiment was deployed near Enid, Oklahoma in Summer of 2016. The dataset from this ultra-dense array provides an excellent opportunity for detecting microseismicity in that region with wavefield approaches. Here we examine continuous waveforms recorded by 3 seismic lines using local coherence for ultra-dense arrays (Li et al., 2017), which is a measure of cross-correlation of waveform at each station with its nearby stations. So far we have detected more than 5,000 events from 06/22/2016 to 07/20/2016, and majority of them are not listed on the regional catalog of Oklahoma or global catalogs, indicating that they are local events. We also identify 15-20 long-period long-duration events, some of them lasting for more than 500 s. Such events have been found at major plate-boundary faults (also known as deep tectonic tremor), as well as during hydraulic fracturing, slow-moving landslides and glaciers. Our next step is to locate these possible tremor-like events with their relative arrival times across the array and compare their occurrence times with solid-earth tides and injection histories to better understand their driving mechanisms.

  4. On the feasibility of using satellite gravity observations for detecting large-scale solid mass transfer events

    Science.gov (United States)

    Peidou, Athina C.; Fotopoulos, Georgia; Pagiatakis, Spiros

    2017-10-01

    The main focus of this paper is to assess the feasibility of utilizing dedicated satellite gravity missions in order to detect large-scale solid mass transfer events (e.g. landslides). Specifically, a sensitivity analysis of Gravity Recovery and Climate Experiment (GRACE) gravity field solutions in conjunction with simulated case studies is employed to predict gravity changes due to past subaerial and submarine mass transfer events, namely the Agulhas slump in southeastern Africa and the Heart Mountain Landslide in northwestern Wyoming. The detectability of these events is evaluated by taking into account the expected noise level in the GRACE gravity field solutions and simulating their impact on the gravity field through forward modelling of the mass transfer. The spectral content of the estimated gravity changes induced by a simulated large-scale landslide event is estimated for the known spatial resolution of the GRACE observations using wavelet multiresolution analysis. The results indicate that both the Agulhas slump and the Heart Mountain Landslide could have been detected by GRACE, resulting in {\\vert }0.4{\\vert } and {\\vert }0.18{\\vert } mGal change on GRACE solutions, respectively. The suggested methodology is further extended to the case studies of the submarine landslide in Tohoku, Japan, and the Grand Banks landslide in Newfoundland, Canada. The detectability of these events using GRACE solutions is assessed through their impact on the gravity field.

  5. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    Science.gov (United States)

    Van Strien, Jan W.; Isbell, Lynne A.

    2017-01-01

    Studies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to partially exposed snake models and scale patterns on the snake skin. Here, we examined whether snake skin patterns and partially exposed snakes elicit a larger EPN in humans. In Task 1, we employed pictures with close-ups of snake skins, lizard skins, and bird plumage. In task 2, we employed pictures of partially exposed snakes, lizards, and birds. Participants watched a random rapid serial visual presentation of these pictures. The EPN was scored as the mean activity (225–300 ms after picture onset) at occipital and parieto-occipital electrodes. Consistent with previous studies, and with the Snake Detection Theory, the EPN was significantly larger for snake skin pictures than for lizard skin and bird plumage pictures, and for lizard skin pictures than for bird plumage pictures. Likewise, the EPN was larger for partially exposed snakes than for partially exposed lizards and birds. The results suggest that the EPN snake effect is partly driven by snake skin scale patterns which are otherwise rare in nature. PMID:28387376

  6. Vision-based Detection of Acoustic Timed Events: a Case Study on Clarinet Note Onsets

    Science.gov (United States)

    Bazzica, A.; van Gemert, J. C.; Liem, C. C. S.; Hanjalic, A.

    2017-05-01

    Acoustic events often have a visual counterpart. Knowledge of visual information can aid the understanding of complex auditory scenes, even when only a stereo mixdown is available in the audio domain, \\eg identifying which musicians are playing in large musical ensembles. In this paper, we consider a vision-based approach to note onset detection. As a case study we focus on challenging, real-world clarinetist videos and carry out preliminary experiments on a 3D convolutional neural network based on multiple streams and purposely avoiding temporal pooling. We release an audiovisual dataset with 4.5 hours of clarinetist videos together with cleaned annotations which include about 36,000 onsets and the coordinates for a number of salient points and regions of interest. By performing several training trials on our dataset, we learned that the problem is challenging. We found that the CNN model is highly sensitive to the optimization algorithm and hyper-parameters, and that treating the problem as binary classification may prevent the joint optimization of precision and recall. To encourage further research, we publicly share our dataset, annotations and all models and detail which issues we came across during our preliminary experiments.

  7. First Satellite-detected Perturbations of Outgoing Longwave Radiation Associated with Blowing Snow Events over Antarctica

    Science.gov (United States)

    Yang, Yuekui; Palm, Stephen P.; Marshak, Alexander; Wu, Dong L.; Yu, Hongbin; Fu, Qiang

    2014-01-01

    We present the first satellite-detected perturbations of the outgoing longwave radiation (OLR) associated with blowing snow events over the Antarctic ice sheet using data from Cloud-Aerosol Lidar with Orthogonal Polarization and Clouds and the Earth's Radiant Energy System. Significant cloud-free OLR differences are observed between the clear and blowing snow sky, with the sign andmagnitude depending on season and time of the day. During nighttime, OLRs are usually larger when blowing snow is present; the average difference in OLRs between without and with blowing snow over the East Antarctic Ice Sheet is about 5.2 W/m2 for the winter months of 2009. During daytime, in contrast, the OLR perturbation is usually smaller or even has the opposite sign. The observed seasonal variations and day-night differences in the OLR perturbation are consistent with theoretical calculations of the influence of blowing snow on OLR. Detailed atmospheric profiles are needed to quantify the radiative effect of blowing snow from the satellite observations.

  8. Real Time Robot Soccer Game Event Detection Using Finite State Machines with Multiple Fuzzy Logic Probability Evaluators

    Directory of Open Access Journals (Sweden)

    Elmer P. Dadios

    2009-01-01

    Full Text Available This paper presents a new algorithm for real time event detection using Finite State Machines with multiple Fuzzy Logic Probability Evaluators (FLPEs. A machine referee for a robot soccer game is developed and is used as the platform to test the proposed algorithm. A novel technique to detect collisions and other events in microrobot soccer game under inaccurate and insufficient information is presented. The robots' collision is used to determine goalkeeper charging and goal score events which are crucial for the machine referee's decisions. The Main State Machine (MSM handles the schedule of event activation. The FLPE calculates the probabilities of the true occurrence of the events. Final decisions about the occurrences of events are evaluated and compared through threshold crisp probability values. The outputs of FLPEs can be combined to calculate the probability of an event composed of subevents. Using multiple fuzzy logic system, the FLPE utilizes minimal number of rules and can be tuned individually. Experimental results show the accuracy and robustness of the proposed algorithm.

  9. Search for non-baryonic dark matter with cryogenic detectors based on ionisation and heat detection. Analysis of experimental data from the Edelweiss-I experiment; Recherche de la matiere noire non-baryonique a l'aide de detecteurs cryogeniques a double composante ionisation et chaleur: Analyse et Interpretation des donnees de l'experience EDELWEISS-I

    Energy Technology Data Exchange (ETDEWEB)

    Sanglard, V

    2005-11-15

    The method of direct detection of WIMPs (weakly interactive massive particles) that are present in the halo of our galaxy rests on the detection of their interaction with a target nucleus. The Edelweiss experiment uses this technique with 3 cryogenic detectors operating on 2 modes ionization and heat. Each detector is made of a 320 g germanium crystal with 2 faces equipped with electrodes. In order to improve the collection of charges, an amorphous layer of Ge or Si is laid between the crystal surface and the electrodes. The validation of the detector system has been made with Co{sup 57} and Cs{sup 137} gamma sources and a Cf{sup 252} neutron source. We present a comparison with simulation results and experimental data for the validation of the response to nuclear recoils. The whole experimental data collected by Edelweiss-I from 2000 till 2003 has been analysed. 40 events have been selected, 6 among them with an energy over 30 keV. Limits for the interaction cross-section between a WIMP and a nucleon have been deduced from the experimental data. The Yellin method has enabled us to determine a limit without knowing the background noise. The best sensitivity appears to be 1.5*10{sup -6} pb for a WIMP's mass of 80 GeV/c{sup 2} and a confidence level of 90 per cent. In terms of events, the limit for an energy range of 30 - 100 keV is 0.12 events per kg and per day. (A.C.)

  10. A new method to detect event-related potentials based on Pearson's correlation.

    Science.gov (United States)

    Giroldini, William; Pederzoli, Luciano; Bilucaglia, Marco; Melloni, Simone; Tressoldi, Patrizio

    2016-12-01

    Event-related potentials (ERPs) are widely used in brain-computer interface applications and in neuroscience.  Normal EEG activity is rich in background noise, and therefore, in order to detect ERPs, it is usually necessary to take the average from multiple trials to reduce the effects of this noise.  The noise produced by EEG activity itself is not correlated with the ERP waveform and so, by calculating the average, the noise is decreased by a factor inversely proportional to the square root of N , where N is the number of averaged epochs. This is the easiest strategy currently used to detect ERPs, which is based on calculating the average of all ERP's waveform, these waveforms being time- and phase-locked.  In this paper, a new method called GW6 is proposed, which calculates the ERP using a mathematical method based only on Pearson's correlation. The result is a graph with the same time resolution as the classical ERP and which shows only positive peaks representing the increase-in consonance with the stimuli-in EEG signal correlation over all channels.  This new method is also useful for selectively identifying and highlighting some hidden components of the ERP response that are not phase-locked, and that are usually hidden in the standard and simple method based on the averaging of all the epochs.  These hidden components seem to be caused by variations (between each successive stimulus) of the ERP's inherent phase latency period (jitter), although the same stimulus across all EEG channels produces a reasonably constant phase. For this reason, this new method could be very helpful to investigate these hidden components of the ERP response and to develop applications for scientific and medical purposes. Moreover, this new method is more resistant to EEG artifacts than the standard calculations of the average and could be very useful in research and neurology.  The method we are proposing can be directly used in the form of a process written in the well

  11. A secure distributed logistic regression protocol for the detection of rare adverse drug events.

    Science.gov (United States)

    El Emam, Khaled; Samet, Saeed; Arbuckle, Luk; Tamblyn, Robyn; Earle, Craig; Kantarcioglu, Murat

    2013-05-01

    There is limited capacity to assess the comparative risks of medications after they enter the market. For rare adverse events, the pooling of data from multiple sources is necessary to have the power and sufficient population heterogeneity to detect differences in safety and effectiveness in genetic, ethnic and clinically defined subpopulations. However, combining datasets from different data custodians or jurisdictions to perform an analysis on the pooled data creates significant privacy concerns that would need to be addressed. Existing protocols for addressing these concerns can result in reduced analysis accuracy and can allow sensitive information to leak. To develop a secure distributed multi-party computation protocol for logistic regression that provides strong privacy guarantees. We developed a secure distributed logistic regression protocol using a single analysis center with multiple sites providing data. A theoretical security analysis demonstrates that the protocol is robust to plausible collusion attacks and does not allow the parties to gain new information from the data that are exchanged among them. The computational performance and accuracy of the protocol were evaluated on simulated datasets. The computational performance scales linearly as the dataset sizes increase. The addition of sites results in an exponential growth in computation time. However, for up to five sites, the time is still short and would not affect practical applications. The model parameters are the same as the results on pooled raw data analyzed in SAS, demonstrating high model accuracy. The proposed protocol and prototype system would allow the development of logistic regression models in a secure manner without requiring the sharing of personal health information. This can alleviate one of the key barriers to the establishment of large-scale post-marketing surveillance programs. We extended the secure protocol to account for correlations among patients within sites through

  12. Indirect detection of dark matter with γ rays.

    Science.gov (United States)

    Funk, Stefan

    2015-10-06

    The details of what constitutes the majority of the mass that makes up dark matter in the Universe remains one of the prime puzzles of cosmology and particle physics today-80 y after the first observational indications. Today, it is widely accepted that dark matter exists and that it is very likely composed of elementary particles, which are weakly interacting and massive [weakly interacting massive particles (WIMPs)]. As important as dark matter is in our understanding of cosmology, the detection of these particles has thus far been elusive. Their primary properties such as mass and interaction cross sections are still unknown. Indirect detection searches for the products of WIMP annihilation or decay. This is generally done through observations of γ-ray photons or cosmic rays. Instruments such as the Fermi large-area telescope, high-energy stereoscopic system, major atmospheric gamma-ray imaging Cherenkov, and very energetic radiation imaging telescope array, combined with the future Cherenkov telescope array, will provide important complementarity to other search techniques. Given the expected sensitivities of all search techniques, we are at a stage where the WIMP scenario is facing stringent tests, and it can be expected that WIMPs will be either be detected or the scenario will be so severely constrained that it will have to be rethought. In this sense, we are on the threshold of discovery. In this article, I will give a general overview of the current status and future expectations for indirect searches of dark matter (WIMP) particles.

  13. Enriched Encoding: Reward Motivation Organizes Cortical Networks for Hippocampal Detection of Unexpected Events

    OpenAIRE

    Murty, Vishnu P.; Adcock, R. Alison

    2013-01-01

    Learning how to obtain rewards requires learning about their contexts and likely causes. How do long-term memory mechanisms balance the need to represent potential determinants of reward outcomes with the computational burden of an over-inclusive memory? One solution would be to enhance memory for salient events that occur during reward anticipation, because all such events are potential determinants of reward. We tested whether reward motivation enhances encoding of salient events like expec...

  14. The necessity of recognizing all events in X-ray detection.

    Science.gov (United States)

    Papp, T; Maxwell, J A; Papp, A T

    2010-01-01

    In our work in studying properties of inner shell ionization, we are troubled that the experimental data used to determine the basic parameters of X-ray physics have a large and unexplainable scatter. As we looked into the problems we found that many of them contradict simple logic, elemental arithmetic, even parity and angular momentum conservation laws. We have identified that the main source of the problems, other than the human factor, is rooted in the signal processing electronics. To overcome these problems we have developed a fully digital signal processor, which not only has excellent resolution and line shape, but also allows proper accounting of all events. This is achieved by processing all events and separating them into two or more spectra (maximum 16), where the first spectrum is the accepted or good spectrum and the second spectrum is the spectrum of all rejected events. The availability of all the events allows one to see the other part of the spectrum. To our surprise the total information explains many of the shortcomings and contradictions of the X-ray database. The data processing methodology cannot be established on the partial and fractional information offered by other approaches. Comparing Monte Carlo detector modeling results with the partial spectra is ambiguous. It suggests that the metrology of calibration by radioactive sources as well as other X-ray measurements could be improved by the availability of the proper accounting of all events. It is not enough to know that an event was rejected and increment the input counter, it is necessary to know, what was rejected and why it happened, whether it was a noise or a disturbed event, a retarded event or a true event, or any pile up combination of these events. Such information is supplied by our processor reporting the events rejected by each discriminator in separate spectra. Several industrial applications of this quality assurance capable signal processor are presented. Copyright 2009

  15. Detection of water-quality contamination events based on multi-sensor fusion using an extented Dempster–Shafer method

    International Nuclear Information System (INIS)

    Hou, Dibo; He, Huimei; Huang, Pingjie; Zhang, Guangxin; Loaiciga, Hugo

    2013-01-01

    This study presents a method for detecting contamination events of sources of drinking water based on the Dempster–Shafer (D-S) evidence theory. The detection method has the purpose of protecting water supply systems against accidental and intentional contamination events. This purpose is achieved by first predicting future water-quality parameters using an autoregressive (AR) model. The AR model predicts future water-quality parameters using recent measurements of these parameters made with automated (on-line) water-quality sensors. Next, a probabilistic method assigns probabilities to the time series of residuals formed by comparing predicted water-quality parameters with threshold values. Finally, the D-S fusion method searches for anomalous probabilities of the residuals and uses the result of that search to determine whether the current water quality is normal (that is, free of pollution) or contaminated. The D-S fusion method is extended and improved in this paper by weighted averaging of water-contamination evidence and by the analysis of the persistence of anomalous probabilities of water-quality parameters. The extended D-S fusion method makes determinations that have a high probability of being correct concerning whether or not a source of drinking water has been contaminated. This paper's method for detecting water-contamination events was tested with water-quality time series from automated (on-line) water quality sensors. In addition, a small-scale, experimental, water-pipe network was tested to detect water-contamination events. The two tests demonstrated that the extended D-S fusion method achieves a low false alarm rate and high probabilities of detecting water contamination events. (paper)

  16. Unified framework for triaxial accelerometer-based fall event detection and classification using cumulants and hierarchical decision tree classifier.

    Science.gov (United States)

    Kambhampati, Satya Samyukta; Singh, Vishal; Manikandan, M Sabarimalai; Ramkumar, Barathram

    2015-08-01

    In this Letter, the authors present a unified framework for fall event detection and classification using the cumulants extracted from the acceleration (ACC) signals acquired using a single waist-mounted triaxial accelerometer. The main objective of this Letter is to find suitable representative cumulants and classifiers in effectively detecting and classifying different types of fall and non-fall events. It was discovered that the first level of the proposed hierarchical decision tree algorithm implements fall detection using fifth-order cumulants and support vector machine (SVM) classifier. In the second level, the fall event classification algorithm uses the fifth-order cumulants and SVM. Finally, human activity classification is performed using the second-order cumulants and SVM. The detection and classification results are compared with those of the decision tree, naive Bayes, multilayer perceptron and SVM classifiers with different types of time-domain features including the second-, third-, fourth- and fifth-order cumulants and the signal magnitude vector and signal magnitude area. The experimental results demonstrate that the second- and fifth-order cumulant features and SVM classifier can achieve optimal detection and classification rates of above 95%, as well as the lowest false alarm rate of 1.03%.

  17. A semi-automated method for rapid detection of ripple events on interictal voltage discharges in the scalp electroencephalogram.

    Science.gov (United States)

    Chu, Catherine J; Chan, Arthur; Song, Dan; Staley, Kevin J; Stufflebeam, Steven M; Kramer, Mark A

    2017-02-01

    High frequency oscillations are emerging as a clinically important indicator of epileptic networks. However, manual detection of these high frequency oscillations is difficult, time consuming, and subjective, especially in the scalp EEG, thus hindering further clinical exploration and application. Semi-automated detection methods augment manual detection by reducing inspection to a subset of time intervals. We propose a new method to detect high frequency oscillations that co-occur with interictal epileptiform discharges. The new method proceeds in two steps. The first step identifies candidate time intervals during which high frequency activity is increased. The second step computes a set of seven features for each candidate interval. These features require that the candidate event contain a high frequency oscillation approximately sinusoidal in shape, with at least three cycles, that co-occurs with a large amplitude discharge. Candidate events that satisfy these features are stored for validation through visual analysis. We evaluate the detector performance in simulation and on ten examples of scalp EEG data, and show that the proposed method successfully detects spike-ripple events, with high positive predictive value, low false positive rate, and high intra-rater reliability. The proposed method is less sensitive than the existing method of visual inspection, but much faster and much more reliable. Accurate and rapid detection of high frequency activity increases the clinical viability of this rhythmic biomarker of epilepsy. The proposed spike-ripple detector rapidly identifies candidate spike-ripple events, thus making clinical analysis of prolonged, multielectrode scalp EEG recordings tractable. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Particle Filter Based Tracking in a Detection Sparse Discrete Event Simulation Environment

    National Research Council Canada - National Science Library

    Borovies, Drew A

    2007-01-01

    .... In actuality, even extremely uncertain or incomplete detections and counter-detections of opposing entities can provide enough data for entities to make reasonably intelligent decisions on the virtual battlefield...

  19. A Data-Driven Monitoring Technique for Enhanced Fall Events Detection

    KAUST Repository

    Zerrouki, Nabil; Harrou, Fouzi; Sun, Ying; Houacine, Amrane

    2016-01-01

    Fall detection is a crucial issue in the health care of seniors. In this work, we propose an innovative method for detecting falls via a simple human body descriptors. The extracted features are discriminative enough to describe human postures

  20. Accuracy and precision of equine gait event detection during walking with limb and trunk mounted inertial sensors

    DEFF Research Database (Denmark)

    Olsen, Emil; Andersen, Pia Haubro; Pfau, Thilo

    2012-01-01

    The increased variations of temporal gait events when pathology is present are good candidate features for objective diagnostic tests. We hypothesised that the gait events hoof-on/off and stance can be detected accurately and precisely using features from trunk and distal limb-mounted Inertial....... Accuracy (bias) and precision (SD of bias) was calculated to compare force plate and IMU timings for gait events. Data were collected from seven horses. One hundred and twenty three (123) front limb steps were analysed; hoof-on was detected with a bias (SD) of -7 (23) ms, hoof-off with 0.7 (37) ms...... and front limb stance with -0.02 (37) ms. A total of 119 hind limb steps were analysed; hoof-on was found with a bias (SD) of -4 (25) ms, hoof-off with 6 (21) ms and hind limb stance with 0.2 (28) ms. IMUs mounted on the distal limbs and sacrum can detect gait events accurately and precisely....

  1. Validating administrative data for the detection of adverse events in older hospitalized patients

    Directory of Open Access Journals (Sweden)

    Ackroyd-Stolarz S

    2014-08-01

    Full Text Available Stacy Ackroyd-Stolarz,1,2 Susan K Bowles,3–5 Lorri Giffin6 1Performance Excellence Portfolio, Capital District Health Authority, Halifax, Nova Scotia, Canada; 2Department of Emergency Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; 3Geriatric Medicine, Capital District Health Authority, Halifax, Nova Scotia, Canada; 4College of Pharmacy and Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; 5Department of Pharmacy at Capital District Health Authority, Halifax, Nova Scotia, Canada; 6South Shore Family Health, Bridgewater, Nova Scotia, Canada Abstract: Older hospitalized patients are at risk of experiencing adverse events including, but not limited to, hospital-acquired pressure ulcers, fall-related injuries, and adverse drug events. A significant challenge in monitoring and managing adverse events is lack of readily accessible information on their occurrence. Purpose: The objective of this retrospective cross-sectional study was to validate diagnostic codes for pressure ulcers, fall-related injuries, and adverse drug events found in routinely collected administrative hospitalization data. Methods: All patients 65 years of age or older discharged between April 1, 2009 and March 31, 2011 from a provincial academic health sciences center in Canada were eligible for inclusion in the validation study. For each of the three types of adverse events, a random sample of 50 patients whose records were positive and 50 patients whose records were not positive for an adverse event was sought for review in the validation study (n=300 records in total. A structured health record review was performed independently by two health care providers with experience in geriatrics, both of whom were unaware of the patient's status with respect to adverse event coding. A physician reviewed 40 records (20 reviewed by each health care provider to establish interrater agreement. Results: A total of 39 pressure ulcers, 56 fall

  2. [Comparison of the "Trigger" tool with the minimum basic data set for detecting adverse events in general surgery].

    Science.gov (United States)

    Pérez Zapata, A I; Gutiérrez Samaniego, M; Rodríguez Cuéllar, E; Gómez de la Cámara, A; Ruiz López, P

    Surgery is a high risk for the occurrence of adverse events (AE). The main objective of this study is to compare the effectiveness of the Trigger tool with the Hospital National Health System registration of Discharges, the minimum basic data set (MBDS), in detecting adverse events in patients admitted to General Surgery and undergoing surgery. Observational and descriptive retrospective study of patients admitted to general surgery of a tertiary hospital, and undergoing surgery in 2012. The identification of adverse events was made by reviewing the medical records, using an adaptation of "Global Trigger Tool" methodology, as well as the (MBDS) registered on the same patients. Once the AE were identified, they were classified according to damage and to the extent to which these could have been avoided. The area under the curve (ROC) were used to determine the discriminatory power of the tools. The Hanley and Mcneil test was used to compare both tools. AE prevalence was 36.8%. The TT detected 89.9% of all AE, while the MBDS detected 28.48%. The TT provides more information on the nature and characteristics of the AE. The area under the curve was 0.89 for the TT and 0.66 for the MBDS. These differences were statistically significant (P<.001). The Trigger tool detects three times more adverse events than the MBDS registry. The prevalence of adverse events in General Surgery is higher than that estimated in other studies. Copyright © 2017 SECA. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. The sequentially discounting autoregressive (SDAR) method for on-line automatic seismic event detecting on long term observation

    Science.gov (United States)

    Wang, L.; Toshioka, T.; Nakajima, T.; Narita, A.; Xue, Z.

    2017-12-01

    In recent years, more and more Carbon Capture and Storage (CCS) studies focus on seismicity monitoring. For the safety management of geological CO2 storage at Tomakomai, Hokkaido, Japan, an Advanced Traffic Light System (ATLS) combined different seismic messages (magnitudes, phases, distributions et al.) is proposed for injection controlling. The primary task for ATLS is the seismic events detection in a long-term sustained time series record. Considering the time-varying characteristics of Signal to Noise Ratio (SNR) of a long-term record and the uneven energy distributions of seismic event waveforms will increase the difficulty in automatic seismic detecting, in this work, an improved probability autoregressive (AR) method for automatic seismic event detecting is applied. This algorithm, called sequentially discounting AR learning (SDAR), can identify the effective seismic event in the time series through the Change Point detection (CPD) of the seismic record. In this method, an anomaly signal (seismic event) can be designed as a change point on the time series (seismic record). The statistical model of the signal in the neighborhood of event point will change, because of the seismic event occurrence. This means the SDAR aims to find the statistical irregularities of the record thought CPD. There are 3 advantages of SDAR. 1. Anti-noise ability. The SDAR does not use waveform messages (such as amplitude, energy, polarization) for signal detecting. Therefore, it is an appropriate technique for low SNR data. 2. Real-time estimation. When new data appears in the record, the probability distribution models can be automatic updated by SDAR for on-line processing. 3. Discounting property. the SDAR introduces a discounting parameter to decrease the influence of present statistic value on future data. It makes SDAR as a robust algorithm for non-stationary signal processing. Within these 3 advantages, the SDAR method can handle the non-stationary time-varying long

  4. Detection of rain events in radiological early warning networks with spectro-dosimetric systems

    Science.gov (United States)

    Dąbrowski, R.; Dombrowski, H.; Kessler, P.; Röttger, A.; Neumaier, S.

    2017-10-01

    Short-term pronounced increases of the ambient dose equivalent rate, due to rainfall are a well-known phenomenon. Increases in the same order of magnitude or even below may also be caused by a nuclear or radiological event, i.e. by artificial radiation. Hence, it is important to be able to identify natural rain events in dosimetric early warning networks and to distinguish them from radiological events. Novel spectrometric systems based on scintillators may be used to differentiate between the two scenarios, because the measured gamma spectra provide significant nuclide-specific information. This paper describes three simple, automatic methods to check whether an dot H*(10) increase is caused by a rain event or by artificial radiation. These methods were applied to measurements of three spectrometric systems based on CeBr3, LaBr3 and SrI2 scintillation crystals, investigated and tested for their practicability at a free-field reference site of PTB.

  5. [Performance and optimisation of a trigger tool for the detection of adverse events in hospitalised adult patients].

    Science.gov (United States)

    Guzmán Ruiz, Óscar; Pérez Lázaro, Juan José; Ruiz López, Pedro

    To characterise the performance of the triggers used in the detection of adverse events (AE) of hospitalised adult patients and to define a simplified panel of triggers to facilitate the detection of AE. Cross-sectional study of charts of patients from a service of internal medicine to detect EA through systematic review of the charts and identification of triggers (clinical event often related to AE), determining if there was AE as the context in which it appeared the trigger. Once the EA was detected, we proceeded to the characterization of the triggers that detected it. Logistic regression was applied to select the triggers with greater AE detection capability. A total of 291 charts were reviewed, with a total of 562 triggers in 103 patients, of which 163 were involved in detecting an AE. The triggers that detected the most AE were "A.1. Pressure ulcer" (9.82%), "B.5. Laxative or enema" (8.59%), "A.8. Agitation" (8.59%), "A.9. Over-sedation" (7.98%), "A.7. Haemorrhage" (6.75%) and "B.4. Antipsychotic" (6.75%). A simplified model was obtained using logistic regression, and included the variable "Number of drugs" and the triggers "Over-sedation", "Urinary catheterisation", "Readmission in 30 days", "Laxative or enema" and "Abrupt medication stop". This model showed a probability of 81% to correctly classify charts with EA or without EA (p <0.001; 95% confidence interval: 0.763-0.871). A high number of triggers were associated with AE. The summary model is capable of detecting a large amount of AE, with a minimum of elements. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Research and development of a high-temperature helium-leak detection system (joint research). Part 1 survey on leakage events and current leak detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Sakaba, Nariaki; Nakazawa, Toshio; Kawasaki, Kozo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Urakami, Masao; Saisyu, Sadanori [Japan Atomic Power Co., Tokyo (Japan)

    2003-03-01

    In High Temperature Gas-cooled Reactors (HTGR), the detection of leakage of helium at an early stage is very important for the safety and stability of operations. Since helium is a colourless gas, it is generally difficult to identify the location and the amount of leakage when very little leakage has occurred. The purpose of this R and D is to develop a helium leak detection system for the high temperature environment appropriate to the HTGR. As the first step in the development, this paper describes the result of surveying leakage events at nuclear facilities inside and outside Japan and current gas leakage detection technology to adapt optical-fibre detection technology to HTGRs. (author)

  7. A Data-Driven Monitoring Technique for Enhanced Fall Events Detection

    KAUST Repository

    Zerrouki, Nabil

    2016-07-26

    Fall detection is a crucial issue in the health care of seniors. In this work, we propose an innovative method for detecting falls via a simple human body descriptors. The extracted features are discriminative enough to describe human postures and not too computationally complex to allow a fast processing. The fall detection is addressed as a statistical anomaly detection problem. The proposed approach combines modeling using principal component analysis modeling with the exponentially weighted moving average (EWMA) monitoring chart. The EWMA scheme is applied on the ignored principal components to detect the presence of falls. Using two different fall detection datasets, URFD and FDD, we have demonstrated the greater sensitivity and effectiveness of the developed method over the conventional PCA-based methods.

  8. INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational-wave Event GW170817

    DEFF Research Database (Denmark)

    Savchenko, V.; Ferrigno, C.; Kuulkers, E.

    2017-01-01

    We report the INTernational Gamma-ray Astrophysics Laboratory (INTEGRAL) detection of the short gamma-ray burst GRB 170817A (discovered by Fermi-GBM) with a signal-to-noise ratio of 4.6, and, for the first time, its association with the gravitational waves (GWs) from binary neutron star (BNS......) merging event GW170817 detected by the LIGO and Virgo observatories. The significance of association between the gamma-ray burst observed by INTEGRAL and GW170817 is 3.2σ, while the association between the Fermi-GBM and INTEGRAL detections is 4.2σ. GRB 170817A was detected by the SPI-ACS instrument about...

  9. One Novel Multiple-Target Plasmid Reference Molecule Targeting Eight Genetically Modified Canola Events for Genetically Modified Canola Detection.

    Science.gov (United States)

    Li, Zhuqing; Li, Xiang; Wang, Canhua; Song, Guiwen; Pi, Liqun; Zheng, Lan; Zhang, Dabing; Yang, Litao

    2017-09-27

    Multiple-target plasmid DNA reference materials have been generated and utilized as good substitutes of matrix-based reference materials in the analysis of genetically modified organisms (GMOs). Herein, we report the construction of one multiple-target plasmid reference molecule, pCAN, which harbors eight GM canola event-specific sequences (RF1, RF2, MS1, MS8, Topas 19/2, Oxy235, RT73, and T45) and a partial sequence of the canola endogenous reference gene PEP. The applicability of this plasmid reference material in qualitative and quantitative PCR assays of the eight GM canola events was evaluated, including the analysis of specificity, limit of detection (LOD), limit of quantification (LOQ), and performance of pCAN in the analysis of various canola samples, etc. The LODs are 15 copies for RF2, MS1, and RT73 assays using pCAN as the calibrator and 10 genome copies for the other events. The LOQ in each event-specific real-time PCR assay is 20 copies. In quantitative real-time PCR analysis, the PCR efficiencies of all event-specific and PEP assays are between 91% and 97%, and the squared regression coefficients (R 2 ) are all higher than 0.99. The quantification bias values varied from 0.47% to 20.68% with relative standard deviation (RSD) from 1.06% to 24.61% in the quantification of simulated samples. Furthermore, 10 practical canola samples sampled from imported shipments in the port of Shanghai, China, were analyzed employing pCAN as the calibrator, and the results were comparable with those assays using commercial certified materials as the calibrator. Concluding from these results, we believe that this newly developed pCAN plasmid is one good candidate for being a plasmid DNA reference material in the detection and quantification of the eight GM canola events in routine analysis.

  10. INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational-wave Event GW170817

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.; Courvoisier, T. J.-L. [ISDC, Department of Astronomy, University of Geneva, Chemin d’Écogia, 16 CH-1290 Versoix (Switzerland); Kuulkers, E. [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Bazzano, A.; Natalucci, L.; Rodi, J. [INAF-Institute for Space Astrophysics and Planetology, Via Fosso del Cavaliere 100, I-00133-Rome (Italy); Brandt, S.; Chenevez, J. [DTU Space, National Space Institute Elektrovej, Building 327 DK-2800 Kongens Lyngby (Denmark); Diehl, R.; Von Kienlin, A. [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Domingo, A. [Centro de Astrobiología (CAB-CSIC/INTA, ESAC Campus), Camino bajo del Castillo S/N, E-28692 Villanueva de la Cañada, Madrid (Spain); Hanlon, L.; Martin-Carrillo, A. [Space Science Group, School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Jourdain, E. [IRAP, Université de Toulouse, CNRS, UPS, CNES, 9 Av. Roche, F-31028 Toulouse (France); Laurent, P.; Lebrun, F. [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris Sorbonne Paris Cité, 10 rue Alice Domont et Léonie Duquet, F-75205 Paris Cedex 13 (France); Lutovinov, A. [Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Mereghetti, S. [INAF, IASF-Milano, via E.Bassini 15, I-20133 Milano (Italy); and others

    2017-10-20

    We report the INTernational Gamma-ray Astrophysics Laboratory ( INTEGRAL ) detection of the short gamma-ray burst GRB 170817A (discovered by Fermi -GBM) with a signal-to-noise ratio of 4.6, and, for the first time, its association with the gravitational waves (GWs) from binary neutron star (BNS) merging event GW170817 detected by the LIGO and Virgo observatories. The significance of association between the gamma-ray burst observed by INTEGRAL and GW170817 is 3.2σ, while the association between the Fermi -GBM and INTEGRAL detections is 4.2σ. GRB 170817A was detected by the SPI-ACS instrument about 2 s after the end of the GW event. We measure a fluence of (1.4 ± 0.4 ± 0.6) × 10{sup −7} erg cm{sup −2} (75–2000 keV), where, respectively, the statistical error is given at the 1σ confidence level, and the systematic error corresponds to the uncertainty in the spectral model and instrument response. We also report on the pointed follow-up observations carried out by INTEGRAL , starting 19.5 hr after the event, and lasting for 5.4 days. We provide a stringent upper limit on any electromagnetic signal in a very broad energy range, from 3 keV to 8 MeV, constraining the soft gamma-ray afterglow flux to <7.1 × 10{sup −11} erg cm{sup −2} s{sup −1} (80–300 keV). Exploiting the unique capabilities of INTEGRAL , we constrained the gamma-ray line emission from radioactive decays that are expected to be the principal source of the energy behind a kilonova event following a BNS coalescence. Finally, we put a stringent upper limit on any delayed bursting activity, for example, from a newly formed magnetar.

  11. Limits on the Spin-Dependent WIMP-Nucleon Cross Sections from the First Science Run of the ZEPLIN-III Experiment

    International Nuclear Information System (INIS)

    Lebedenko, V. N.; Bewick, A.; Currie, A.; Davidge, D.; Dawson, J.; Horn, M.; Howard, A. S.; Jones, W. G.; Joshi, M.; Liubarsky, I.; Lyons, K.; Quenby, J. J.; Sumner, T. J.; Thorne, C.; Walker, R. J.; Araujo, H. M.; Edwards, B.; Barnes, E. J.; Ghag, C.; Murphy, A. StJ.

    2009-01-01

    We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of ∼450 kg·days fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of σ n =1.9x10 -2 pb at 55 GeV/c 2 WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes 129 Xe and 131 Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of ∼2.

  12. From superWIMPs to decaying dark matter. Models, bounds and indirect searches

    Energy Technology Data Exchange (ETDEWEB)

    Weniger, Christoph

    2010-06-15

    Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1){sub X} gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1){sub em}. We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)

  13. From superWIMPs to decaying dark matter. Models, bounds and indirect searches

    International Nuclear Information System (INIS)

    Weniger, Christoph

    2010-06-01

    Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1) X gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1) em . We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)

  14. Online surveillance of media health event reporting in Nepal: digital disease detection from a One Health perspective.

    Science.gov (United States)

    Schwind, Jessica S; Norman, Stephanie A; Karmacharya, Dibesh; Wolking, David J; Dixit, Sameer M; Rajbhandari, Rajesh M; Mekaru, Sumiko R; Brownstein, John S

    2017-09-21

    Traditional media and the internet are crucial sources of health information. Media can significantly shape public opinion, knowledge and understanding of emerging and endemic health threats. As digital communication rapidly progresses, local access and dissemination of health information contribute significantly to global disease detection and reporting. Health event reports in Nepal (October 2013-December 2014) were used to characterize Nepal's media environment from a One Health perspective using HealthMap - a global online disease surveillance and mapping tool. Event variables (location, media source type, disease or risk factor of interest, and affected species) were extracted from HealthMap. A total of 179 health reports were captured from various sources including newspapers, inter-government agency bulletins, individual reports, and trade websites, yielding 108 (60%) unique articles. Human health events were reported most often (n = 85; 79%), followed by animal health events (n = 23; 21%), with no reports focused solely on environmental health. By expanding event coverage across all of the health sectors, media in developing countries could play a crucial role in national risk communication efforts and could enhance early warning systems for disasters and disease outbreaks.

  15. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    NARCIS (Netherlands)

    J.W. van Strien (Jan); L.A. Isbell (Lynne A.)

    2017-01-01

    textabstractStudies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to

  16. Detection and monitoring of two dust storm events by multispectral modis images.

    Digital Repository Service at National Institute of Oceanography (India)

    Mehta P.S.; Kunte, P.D.

    of Oman, over Arabian Sea to the coast of Pakistan. The dust storm lasted over the Arabian Sea till 30th March. MODIS sensors on both Terra and Aqua Satellites captured images of both events. From the difference in emissive/transmissive nature...

  17. Oil spill detection and remote sensing : an overview with focus on recent events

    International Nuclear Information System (INIS)

    Coolbaugh, T.S.

    2008-01-01

    Several offshore oil spills occurred during the period from November to December 2007 in various parts of the world, each highlighting the need of quickly detect oil spills in marine settings. Several factors must be considered in order to determine the best technical approach for successful detection and oil spill monitoring. These include the reason for detection or monitoring; the location of the spill; the scale of spatial coverage; availability of detection equipment and time to deploy; high specificity for petroleum oil; weather conditions at and above the spill site; and cost of the detection approach. This paper outlined some of the key attributes of several remote sensing options that are available today or being considered. The approaches used to enhance visualization or detection of spills include traditional electromagnetic spectrum-based approaches such as ultra violet (UV), visible, infra-red (IR), radar, and fluorescence-based systems. Analytical approaches such as chemical analysis for the detection of volatile organic compounds (VOCs) or monitoring of electrical conductivity of the water surface may also provide a warning that hydrocarbons have been released. 12 refs., 3 tabs., 11 figs

  18. Control Surface Fault Diagnosis with Specified Detection Probability - Real Event Experiences

    DEFF Research Database (Denmark)

    Hansen, Søren; Blanke, Mogens

    2013-01-01

    desired levels of false alarms and detection probabilities. Self-tuning residual generators are employed for diagnosis and are combined with statistical change detection to form a setup for robust fault diagnosis. On-line estimation of test statistics is used to obtain a detection threshold and a desired...... false alarm probability. A data based method is used to determine the validity of the methods proposed. Verification is achieved using real data and shows that the presented diagnosis method is efficient and could have avoided incidents where faults led to loss of aircraft....

  19. Detecting Specific Health-Related Events Using an Integrated Sensor System for Vital Sign Monitoring

    Directory of Open Access Journals (Sweden)

    Mourad Adnane

    2009-09-01

    Full Text Available In this paper, a new method for the detection of apnea/hypopnea periods in physiological data is presented. The method is based on the intelligent combination of an integrated sensor system for long-time cardiorespiratory signal monitoring and dedicated signal-processing packages. Integrated sensors are a PVDF film and conductive fabric sheets. The signal processing package includes dedicated respiratory cycle (RC and QRS complex detection algorithms and a new method using the respiratory cycle variability (RCV for detecting apnea/hypopnea periods in physiological data. Results show that our method is suitable for online analysis of long time series data.

  20. Real-time detection of organic contamination events in water distribution systems by principal components analysis of ultraviolet spectral data.

    Science.gov (United States)

    Zhang, Jian; Hou, Dibo; Wang, Ke; Huang, Pingjie; Zhang, Guangxin; Loáiciga, Hugo

    2017-05-01

    The detection of organic contaminants in water distribution systems is essential to protect public health from potential harmful compounds resulting from accidental spills or intentional releases. Existing methods for detecting organic contaminants are based on quantitative analyses such as chemical testing and gas/liquid chromatography, which are time- and reagent-consuming and involve costly maintenance. This study proposes a novel procedure based on discrete wavelet transform and principal component analysis for detecting organic contamination events from ultraviolet spectral data. Firstly, the spectrum of each observation is transformed using discrete wavelet with a coiflet mother wavelet to capture the abrupt change along the wavelength. Principal component analysis is then employed to approximate the spectra based on capture and fusion features. The significant value of Hotelling's T 2 statistics is calculated and used to detect outliers. An alarm of contamination event is triggered by sequential Bayesian analysis when the outliers appear continuously in several observations. The effectiveness of the proposed procedure is tested on-line using a pilot-scale setup and experimental data.

  1. Mining the IPTV Channel Change Event Stream to Discover Insight and Detect Ads

    Directory of Open Access Journals (Sweden)

    Matej Kren

    2016-01-01

    Full Text Available IPTV has been widely deployed throughout the world, bringing significant advantages to users in terms of the channel offering, video on demand, and interactive applications. One aspect that has been often neglected is the ability of precise and unobtrusive telemetry. TV set-top boxes that are deployed in modern IPTV systems can be thought of as capable sensor nodes that collect vast amounts of data, representing both the user activity and the quality of service delivered by the system itself. In this paper we focus on the user-generated events and analyze how the data stream of channel change events received from the entire IPTV network can be mined to obtain insight about the content. We demonstrate that it is possible to predict the occurrence of TV ads with high probability and show that the approach could be extended to model the user behavior and classify the viewership in multiple dimensions.

  2. The association of incidentally detected heart valve calcification with future cardiovascular events

    OpenAIRE

    Gondrie, Martijn J. A.; van der Graaf, Yolanda; Jacobs, Peter C.; Oen, Ay L.; Mali, Willem P. Th. M.

    2010-01-01

    Objectives This study aims to investigate the prognostic value of incidental aortic valve calcification (AVC), mitral valve calcification (MVC) and mitral annular calcification (MAC) for cardiovascular events and non-rheumatic valve disease in particular on routine diagnostic chest CT. Methods The study followed a case-cohort design. 10410 patients undergoing chest CT were followed for a median period of 17 months. Patients referred for cardiovascular disease were excluded. A random sample of...

  3. Passive Visual Analytics of Social Media Data for Detection of Unusual Events

    OpenAIRE

    Rustagi, Kush; Chae, Junghoon

    2016-01-01

    Now that social media sites have gained substantial traction, huge amounts of un-analyzed valuable data are being generated. Posts containing images and text have spatiotemporal data attached as well, having immense value for increasing situational awareness of local events, providing insights for investigations and understanding the extent of incidents, their severity, and consequences, as well as their time-evolving nature. However, the large volume of unstructured social media data hinders...

  4. Enriched encoding: reward motivation organizes cortical networks for hippocampal detection of unexpected events.

    Science.gov (United States)

    Murty, Vishnu P; Adcock, R Alison

    2014-08-01

    Learning how to obtain rewards requires learning about their contexts and likely causes. How do long-term memory mechanisms balance the need to represent potential determinants of reward outcomes with the computational burden of an over-inclusive memory? One solution would be to enhance memory for salient events that occur during reward anticipation, because all such events are potential determinants of reward. We tested whether reward motivation enhances encoding of salient events like expectancy violations. During functional magnetic resonance imaging, participants performed a reaction-time task in which goal-irrelevant expectancy violations were encountered during states of high- or low-reward motivation. Motivation amplified hippocampal activation to and declarative memory for expectancy violations. Connectivity of the ventral tegmental area (VTA) with medial prefrontal, ventrolateral prefrontal, and visual cortices preceded and predicted this increase in hippocampal sensitivity. These findings elucidate a novel mechanism whereby reward motivation can enhance hippocampus-dependent memory: anticipatory VTA-cortical-hippocampal interactions. Further, the findings integrate literatures on dopaminergic neuromodulation of prefrontal function and hippocampus-dependent memory. We conclude that during reward motivation, VTA modulation induces distributed neural changes that amplify hippocampal signals and records of expectancy violations to improve predictions-a potentially unique contribution of the hippocampus to reward learning. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Detection of explosive cough events in audio recordings by internal sound analysis.

    Science.gov (United States)

    Rocha, B M; Mendes, L; Couceiro, R; Henriques, J; Carvalho, P; Paiva, R P

    2017-07-01

    We present a new method for the discrimination of explosive cough events, which is based on a combination of spectral content descriptors and pitch-related features. After the removal of near-silent segments, a vector of event boundaries is obtained and a proposed set of 9 features is extracted for each event. Two data sets, recorded using electronic stethoscopes and comprising a total of 46 healthy subjects and 13 patients, were employed to evaluate the method. The proposed feature set is compared to three other sets of descriptors: a baseline, a combination of both sets, and an automatic selection of the best 10 features from both sets. The combined feature set yields good results on the cross-validated database, attaining a sensitivity of 92.3±2.3% and a specificity of 84.7±3.3%. Besides, this feature set seems to generalize well when it is trained on a small data set of patients, with a variety of respiratory and cardiovascular diseases, and tested on a bigger data set of mostly healthy subjects: a sensitivity of 93.4% and a specificity of 83.4% are achieved in those conditions. These results demonstrate that complementing the proposed feature set with a baseline set is a promising approach.

  6. {sup 123}I-MIBG imaging detects cardiac involvement and predicts cardiac events in Churg-Strauss syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, Yoriko; Morita, Yukiko [National Hospital Organization Sagamihara National Hospital, Department of Cardiology, Sagamihara City, Kanagawa (Japan); Tsurikisawa, Naomi; Akiyama, Kazuo [National Hospital Organization Sagamihara National Hospital, Clinical Research Centre for Allergy and Rheumatology, Sagamihara City, Kanagawa (Japan)

    2011-02-15

    In Churg-Strauss syndrome (CSS) it is important to detect cardiac involvement, which predicts poor prognosis. This study evaluated whether {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy could detect cardiac damage and predict cardiac events in CSS. {sup 123}I-MIBG scintigraphy was performed in 28 patients with CSS, 12 of whom had cardiac involvement. The early and delayed heart to mediastinum ratio (early H/M and delayed H/M) and washout rate were calculated by using {sup 123}I-MIBG scintigraphy and compared with those in control subjects. Early H/M and delayed H/M were significantly lower and the washout rate was significantly higher in patients with cardiac involvement than in those without and in controls (early H/M, p = 0.0024, p = 0.0001; delayed H/M, p = 0.0002, p = 0.0001; washout rate, p = 0.0012, p = 0.0052 vs those without and vs controls, respectively). Accuracy for detecting cardiac involvement was 86% for delayed H/M and washout rate and 79% for early H/M and B-type natriuretic peptide (BNP). Kaplan-Meier analysis showed significantly lower cardiac event-free rates in patients with early H/M {<=} 2.18 and BNP > 21.8 pg/ml than those with early H/M > 2.18 and BNP {<=} 21.8 pg/ml (log-rank test p = 0.006). Cardiac sympathetic nerve function was damaged in CSS patients with cardiac involvement. {sup 123}I-MIBG scintigraphy was useful in detecting cardiac involvement and in predicting cardiac events. (orig.)

  7. 123I-MIBG imaging detects cardiac involvement and predicts cardiac events in Churg-Strauss syndrome

    International Nuclear Information System (INIS)

    Horiguchi, Yoriko; Morita, Yukiko; Tsurikisawa, Naomi; Akiyama, Kazuo

    2011-01-01

    In Churg-Strauss syndrome (CSS) it is important to detect cardiac involvement, which predicts poor prognosis. This study evaluated whether 123 I-metaiodobenzylguanidine (MIBG) scintigraphy could detect cardiac damage and predict cardiac events in CSS. 123 I-MIBG scintigraphy was performed in 28 patients with CSS, 12 of whom had cardiac involvement. The early and delayed heart to mediastinum ratio (early H/M and delayed H/M) and washout rate were calculated by using 123 I-MIBG scintigraphy and compared with those in control subjects. Early H/M and delayed H/M were significantly lower and the washout rate was significantly higher in patients with cardiac involvement than in those without and in controls (early H/M, p = 0.0024, p = 0.0001; delayed H/M, p = 0.0002, p = 0.0001; washout rate, p = 0.0012, p = 0.0052 vs those without and vs controls, respectively). Accuracy for detecting cardiac involvement was 86% for delayed H/M and washout rate and 79% for early H/M and B-type natriuretic peptide (BNP). Kaplan-Meier analysis showed significantly lower cardiac event-free rates in patients with early H/M ≤ 2.18 and BNP > 21.8 pg/ml than those with early H/M > 2.18 and BNP ≤ 21.8 pg/ml (log-rank test p = 0.006). Cardiac sympathetic nerve function was damaged in CSS patients with cardiac involvement. 123 I-MIBG scintigraphy was useful in detecting cardiac involvement and in predicting cardiac events. (orig.)

  8. Short Personality and Life Event scale for detection of suicide attempters.

    Science.gov (United States)

    Artieda-Urrutia, Paula; Delgado-Gómez, David; Ruiz-Hernández, Diego; García-Vega, Juan Manuel; Berenguer, Nuria; Oquendo, Maria A; Blasco-Fontecilla, Hilario

    2015-01-01

    To develop a brief and reliable psychometric scale to identify individuals at risk for suicidal behaviour. Case-control study. 182 individuals (61 suicide attempters, 57 psychiatric controls, and 64 psychiatrically healthy controls) aged 18 or older, admitted to the Emergency Department at Puerta de Hierro University Hospital in Madrid, Spain. All participants completed a form including their socio-demographic and clinical characteristics, and the Personality and Life Events scale (27 items). To assess Axis I diagnoses, all psychiatric patients (including suicide attempters) were administered the Mini International Neuropsychiatric Interview. Descriptive statistics were computed for the socio-demographic factors. Additionally, χ(2) independence tests were applied to evaluate differences in socio-demographic and clinical variables, and the Personality and Life Events scale between groups. A stepwise linear regression with backward variable selection was conducted to build the Short Personality Life Event (S-PLE) scale. In order to evaluate the accuracy, a ROC analysis was conducted. The internal reliability was assessed using Cronbach's α, and the external reliability was evaluated using a test-retest procedure. The S-PLE scale, composed of just 6 items, showed good performance in discriminating between medical controls, psychiatric controls and suicide attempters in an independent sample. For instance, the S-PLE scale discriminated between past suicide and past non-suicide attempters with sensitivity of 80% and specificity of 75%. The area under the ROC curve was 88%. A factor analysis extracted only one factor, revealing a single dimension of the S-PLE scale. Furthermore, the S-PLE scale provides values of internal and external reliability between poor (test-retest: 0.55) and acceptable (Cronbach's α: 0.65) ranges. Administration time is about one minute. The S-PLE scale is a useful and accurate instrument for estimating the risk of suicidal behaviour in

  9. MEDUSA: Mining Events to Detect Undesirable uSer Actions in SCADA

    NARCIS (Netherlands)

    Hadziosmanovic, D.; Bolzoni, D.; Hartel, Pieter H.; Jha, Somesh; Sommer, Robin; Kreibich, Christian

    2010-01-01

    Standard approaches for detecting malicious behaviors, e.g. monitoring network traffic, cannot address process-related threats in SCADA(Supervisory Control And Data Acquisition) systems. These threats take place when an attacker gains user access rights and performs actions which look legitimate,

  10. Extranuclear detection of histones and nucleosomes in activated human lymphoblasts as an early event in apoptosis.

    NARCIS (Netherlands)

    Gabler, C.; Blank, N.; Hieronymus, T.; Schiller, M.; Berden, J.H.M.; Kalden, J.R.; Lorenz, H.M.

    2004-01-01

    OBJECTIVE: To evaluate the presence of histones and nucleosomes in cell lysates of freshly isolated peripheral blood mononuclear cells (PBMC), fully activated lymphoblasts, or lymphoblasts after induction of apoptosis. METHODS: Each histone class (H1, H2A, H2B, H3, and H4) was detected by western

  11. USBeSafe: Applying One Class SVM for Effective USB Event Anomaly Detection

    Science.gov (United States)

    2016-04-25

    2012. [5] Phil Muncaster. Indian navy computers stormed by malware-ridden USBs. 2012. [6] Ponemon. 2011 Second Annual Cost of Cyber Crime Study...Zhang, and Shanshan Sun. “A mixed unsu- pervised clustering-based intrusion detection model”. In: Genetic and Evolutionary Computing, 2009. WGEC’09

  12. myBlackBox: Blackbox Mobile Cloud Systems for Personalized Unusual Event Detection

    Directory of Open Access Journals (Sweden)

    Junho Ahn

    2016-05-01

    Full Text Available We demonstrate the feasibility of constructing a novel and practical real-world mobile cloud system, called myBlackBox, that efficiently fuses multimodal smartphone sensor data to identify and log unusual personal events in mobile users’ daily lives. The system incorporates a hybrid architectural design that combines unsupervised classification of audio, accelerometer and location data with supervised joint fusion classification to achieve high accuracy, customization, convenience and scalability. We show the feasibility of myBlackBox by implementing and evaluating this end-to-end system that combines Android smartphones with cloud servers, deployed for 15 users over a one-month period.

  13. Exploring design tradeoffs of a distributed algorithm for cosmic ray event detection

    Science.gov (United States)

    Yousaf, S.; Bakhshi, R.; van Steen, M.; Voulgaris, S.; Kelley, J. L.

    2013-03-01

    Many sensor networks, including large particle detector arrays measuring high-energy cosmic-ray air showers, traditionally rely on centralised trigger algorithms to find spatial and temporal coincidences of individual nodes. Such schemes suffer from scalability problems, especially if the nodes communicate wirelessly or have bandwidth limitations. However, nodes which instead communicate with each other can, in principle, use a distributed algorithm to find coincident events themselves without communication with a central node. We present such an algorithm and consider various design tradeoffs involved, in the context of a potential trigger for the Auger Engineering Radio Array (AERA).

  14. Revisiting the direct detection of dark matter in simplified models

    OpenAIRE

    Li, Tong

    2018-01-01

    In this work we numerically re-examine the loop-induced WIMP-nucleon scattering cross section for the simplified dark matter models and the constraint set by the latest direct detection experiment. We consider a fermion, scalar or vector dark matter component from five simplified models with leptophobic spin-0 mediators coupled only to Standard Model quarks and dark matter particles. The tree-level WIMP-nucleon cross sections in these models are all momentum-suppressed. We calculate the non-s...

  15. The Tendency of the Crest Factor Helps Detect Nascent Events; Electronic Circuit, Software and Applications to Signals from Diverse Fields

    Directory of Open Access Journals (Sweden)

    Núñez-Pérez Ricardo Francisco

    2014-04-01

    Full Text Available Within the signal analysis techniques in the time domain, the crest factor (CF is undoubtedly one of the most simple and fast to implement using electronic circuits and/or software. That's why it has been used reliably to care for machinery and to evaluate the quality of supply. One of the major manufacturers of instruments for these purposes is Bruel and Kjaer and defines the crest factor of voltage or repetitive current signal as the ratio of the peak level and its rms value during a certain period of time. In this paper, we try to find out experimentally the potential of CF and their tendency to detect the nascent and evolution of events in various fields of knowledge, either by generating it with a developed electronic circuit, or with calculations, through routines that are performed with the programs DADISP and LabVIEW. The results are validated and checked for all the above factors and trends through a comparison between them and the proposed features and specifications. The results were acceptable so that the tools were applied to detect early faults in electrical machines, to identify chaosity differences between the circuits with these dynamics, to detect abnormal respiratory distress or rales in patients and to detect harmful distortions in the electrical current, all this based on simulations and measurements for each of the 4 cases studied. Other CF original applications proposed are: a control of chaos in electronic circuits that stir/ mix industrial processes and b correct the power factor of non-linear and inductive loads. A medium-term study and use a CF that considers the maximum signal peak to peak is contemplated, and it is thought that it can improve event detection

  16. ON THE DETECTABILITY OF A PREDICTED MESOLENSING EVENT ASSOCIATED WITH THE HIGH PROPER MOTION STAR VB 10

    International Nuclear Information System (INIS)

    Lépine, Sébastien; DiStefano, Rosanne

    2012-01-01

    Extrapolation of the astrometric motion of the nearby low-mass star VB 10 indicates that sometime in late 2011 December or during the first 2-3 months of 2012, the star will make a close approach to a background point source. Based on astrometric uncertainties, we estimate a 1 in 2 chance that the distance of closest approach ρ min will be less than 100 mas, a 1 in 5 chance that ρ min min J planet on a moderately wide (≈0.18 AU–0.84 AU) orbit, there is a chance (1% to more than 10%, depending on the distance of closest approach and orbital period and inclination) that a passage of the planet closer to the background source will result in a secondary event of higher magnification. The detection of secondary events could be made possible with a several-times-per-night multi-site monitoring campaign.

  17. DETECTION OF SUPERSONIC DOWNFLOWS AND ASSOCIATED HEATING EVENTS IN THE TRANSITION REGION ABOVE SUNSPOTS

    Energy Technology Data Exchange (ETDEWEB)

    Kleint, L.; Martínez-Sykora, J. [Bay Area Environmental Research Institute, 625 2nd Street, Ste. 209, Petaluma, CA (United States); Antolin, P. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Tian, H.; Testa, P.; Reeves, K. K.; McKillop, S.; Saar, S.; Golub, L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Judge, P. [High Altitude Observatory/NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); De Pontieu, B.; Wuelser, J. P.; Boerner, P.; Hurlburt, N.; Lemen, J.; Tarbell, T. D.; Title, A. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover St., Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States); Carlsson, M.; Hansteen, V. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway); Jaeggli, S., E-mail: lucia.kleint@fhnw.ch [Department of Physics, Montana State University, Bozeman, P.O. Box 173840, Bozeman, MT 59717 (United States); and others

    2014-07-10

    Interface Region Imaging Spectrograph data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0.''33. On 2013 August 30, we observed bursts of high Doppler shifts suggesting strong supersonic downflows of up to 200 km s{sup –1} and weaker, slightly slower upflows in the spectral lines Mg II h and k, C II 1336, Si IV 1394 Å, and 1403 Å, that are correlated with brightenings in the slitjaw images (SJIs). The bursty behavior lasts throughout the 2 hr observation, with average burst durations of about 20 s. The locations of these short-lived events appear to be the umbral and penumbral footpoints of EUV loops. Fast apparent downflows are observed along these loops in the SJIs and in the Atmospheric Imaging Assembly, suggesting that the loops are thermally unstable. We interpret the observations as cool material falling from coronal heights, and especially coronal rain produced along the thermally unstable loops, which leads to an increase of intensity at the loop footpoints, probably indicating an increase of density and temperature in the TR. The rain speeds are on the higher end of previously reported speeds for this phenomenon, and possibly higher than the free-fall velocity along the loops. On other observing days, similar bright dots are sometimes aligned into ribbons, resembling small flare ribbons. These observations provide a first insight into small-scale heating events in sunspots in the TR.

  18. NuSTAR Detection of X-Ray Heating Events in the Quiet Sun

    Science.gov (United States)

    Kuhar, Matej; Krucker, Säm; Glesener, Lindsay; Hannah, Iain G.; Grefenstette, Brian W.; Smith, David M.; Hudson, Hugh S.; White, Stephen M.

    2018-04-01

    The explanation of the coronal heating problem potentially lies in the existence of nanoflares, numerous small-scale heating events occurring across the whole solar disk. In this Letter, we present the first imaging spectroscopy X-ray observations of three quiet Sun flares during the Nuclear Spectroscopic Telescope ARray (NuSTAR) solar campaigns on 2016 July 26 and 2017 March 21, concurrent with the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) observations. Two of the three events showed time lags of a few minutes between peak X-ray and extreme ultraviolet emissions. Isothermal fits with rather low temperatures in the range 3.2–4.1 MK and emission measures of (0.6–15) × 1044 cm‑3 describe their spectra well, resulting in thermal energies in the range (2–6) × 1026 erg. NuSTAR spectra did not show any signs of a nonthermal or higher temperature component. However, as the estimated upper limits of (hidden) nonthermal energy are comparable to the thermal energy estimates, the lack of a nonthermal component in the observed spectra is not a constraining result. The estimated Geostationary Operational Environmental Satellite (GOES) classes from the fitted values of temperature and emission measure fall between 1/1000 and 1/100 A class level, making them eight orders of magnitude fainter in soft X-ray flux than the largest solar flares.

  19. Semi-automated camera trap image processing for the detection of ungulate fence crossing events.

    Science.gov (United States)

    Janzen, Michael; Visser, Kaitlyn; Visscher, Darcy; MacLeod, Ian; Vujnovic, Dragomir; Vujnovic, Ksenija

    2017-09-27

    Remote cameras are an increasingly important tool for ecological research. While remote camera traps collect field data with minimal human attention, the images they collect require post-processing and characterization before it can be ecologically and statistically analyzed, requiring the input of substantial time and money from researchers. The need for post-processing is due, in part, to a high incidence of non-target images. We developed a stand-alone semi-automated computer program to aid in image processing, categorization, and data reduction by employing background subtraction and histogram rules. Unlike previous work that uses video as input, our program uses still camera trap images. The program was developed for an ungulate fence crossing project and tested against an image dataset which had been previously processed by a human operator. Our program placed images into categories representing the confidence of a particular sequence of images containing a fence crossing event. This resulted in a reduction of 54.8% of images that required further human operator characterization while retaining 72.6% of the known fence crossing events. This program can provide researchers using remote camera data the ability to reduce the time and cost required for image post-processing and characterization. Further, we discuss how this procedure might be generalized to situations not specifically related to animal use of linear features.

  20. Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high-intensity ultrasound.

    Science.gov (United States)

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Fink, Mathias; Tanter, Mickaël

    2011-03-01

    The activation of natural gas nuclei to induce larger bubbles is possible using short ultrasonic excitations of high amplitude, and is required for ultrasound cavitation therapies. However, little is known about the distribution of nuclei in tissues. Therefore, the acoustic pressure level necessary to generate bubbles in a targeted zone and their exact location are currently difficult to predict. To monitor the initiation of cavitation activity, a novel all-ultrasound technique sensitive to single nucleation events is presented here. It is based on combined passive detection and ultrafast active imaging over a large volume using the same multi-element probe. Bubble nucleation was induced using a focused transducer (660 kHz, f-number = 1) driven by a high-power electric burst (up to 300 W) of one to two cycles. Detection was performed with a linear array (4 to 7 MHz) aligned with the single-element focal point. In vitro experiments in gelatin gel and muscular tissue are presented. The synchronized passive detection enabled radio-frequency data to be recorded, comprising high-frequency coherent wave fronts as signatures of the acoustic emissions linked to the activation of the nuclei. Active change detection images were obtained by subtracting echoes collected in the unnucleated medium. These indicated the appearance of stable cavitating regions. Because of the ultrafast frame rate, active detection occurred as quickly as 330 μs after the high-amplitude excitation and the dynamics of the induced regions were studied individually.

  1. Using additional external inputs to forecast water quality with an artificial neural network for contamination event detection in source water

    Science.gov (United States)

    Schmidt, F.; Liu, S.

    2016-12-01

    Source water quality plays an important role for the safety of drinking water and early detection of its contamination is vital to taking appropriate countermeasures. However, compared to drinking water, it is more difficult to detect contamination events because its environment is less controlled and numerous natural causes contribute to a high variability of the background values. In this project, Artificial Neural Networks (ANNs) and a Contamination Event Detection Process (CED Process) were used to identify events in river water. The ANN models the response of basic water quality sensors obtained in laboratory experiments in an off-line learning stage and continuously forecasts future values of the time line in an on-line forecasting step. During this second stage, the CED Process compares the forecast to the measured value and classifies it as regular background or event value, which modifies the ANN's continuous learning and influences its forecasts. In addition to this basic setup, external information is fed to the CED Process: A so-called Operator Input (OI) is provided to inform about unusual water quality levels that are unrelated to the presence of contamination, for example due to cooling water discharge from a nearby power plant. This study's primary goal is to evaluate how well the OI fits into the design of the combined forecasting ANN and CED Process and to understand its effects on the online forecasting stage. To test this, data from laboratory experiments conducted previously at the School of Environment, Tsinghua University, have been used to perform simulations highlighting features and drawbacks of this method. Applying the OI has been shown to have a positive influence on the ANN's ability to handle a sudden change in background values, which is unrelated to contamination. However, it might also mask the presence of an event, an issue that underlines the necessity to have several instances of the algorithm run in parallel. Other difficulties

  2. Multiscale vision model for event detection and reconstruction in two-photon imaging data

    DEFF Research Database (Denmark)

    Brazhe, Alexey; Mathiesen, Claus; Lind, Barbara Lykke

    2014-01-01

    on a modified multiscale vision model, an object detection framework based on the thresholding of wavelet coefficients and hierarchical trees of significant coefficients followed by nonlinear iterative partial object reconstruction, for the analysis of two-photon calcium imaging data. The framework is discussed...... of the multiscale vision model is similar in the denoising, but provides a better segmenation of the image into meaningful objects, whereas other methods need to be combined with dedicated thresholding and segmentation utilities....

  3. CISN ShakeAlert: Faster Warning Information Through Multiple Threshold Event Detection in the Virtual Seismologist (VS) Early Warning Algorithm

    Science.gov (United States)

    Cua, G. B.; Fischer, M.; Caprio, M.; Heaton, T. H.; Cisn Earthquake Early Warning Project Team

    2010-12-01

    The Virtual Seismologist (VS) earthquake early warning (EEW) algorithm is one of 3 EEW approaches being incorporated into the California Integrated Seismic Network (CISN) ShakeAlert system, a prototype EEW system that could potentially be implemented in California. The VS algorithm, implemented by the Swiss Seismological Service at ETH Zurich, is a Bayesian approach to EEW, wherein the most probable source estimate at any given time is a combination of contributions from a likehihood function that evolves in response to incoming data from the on-going earthquake, and selected prior information, which can include factors such as network topology, the Gutenberg-Richter relationship or previously observed seismicity. The VS codes have been running in real-time at the Southern California Seismic Network since July 2008, and at the Northern California Seismic Network since February 2009. We discuss recent enhancements to the VS EEW algorithm that are being integrated into CISN ShakeAlert. We developed and continue to test a multiple-threshold event detection scheme, which uses different association / location approaches depending on the peak amplitudes associated with an incoming P pick. With this scheme, an event with sufficiently high initial amplitudes can be declared on the basis of a single station, maximizing warning times for damaging events for which EEW is most relevant. Smaller, non-damaging events, which will have lower initial amplitudes, will require more picks to initiate an event declaration, with the goal of reducing false alarms. This transforms the VS codes from a regional EEW approach reliant on traditional location estimation (and the requirement of at least 4 picks as implemented by the Binder Earthworm phase associator) into an on-site/regional approach capable of providing a continuously evolving stream of EEW information starting from the first P-detection. Real-time and offline analysis on Swiss and California waveform datasets indicate that the

  4. Evaluating Monitoring Strategies to Detect Precipitation-Induced Microbial Contamination Events in Karstic Springs Used for Drinking Water

    Directory of Open Access Journals (Sweden)

    Michael D. Besmer

    2017-11-01

    Full Text Available Monitoring of microbial drinking water quality is a key component for ensuring safety and understanding risk, but conventional monitoring strategies are typically based on low sampling frequencies (e.g., quarterly or monthly. This is of concern because many drinking water sources, such as karstic springs are often subject to changes in bacterial concentrations on much shorter time scales (e.g., hours to days, for example after precipitation events. Microbial contamination events are crucial from a risk assessment perspective and should therefore be targeted by monitoring strategies to establish both the frequency of their occurrence and the magnitude of bacterial peak concentrations. In this study we used monitoring data from two specific karstic springs. We assessed the performance of conventional monitoring based on historical records and tested a number of alternative strategies based on a high-resolution data set of bacterial concentrations in spring water collected with online flow cytometry (FCM. We quantified the effect of increasing sampling frequency and found that for the specific case studied, at least bi-weekly sampling would be needed to detect precipitation events with a probability of >90%. We then proposed an optimized monitoring strategy with three targeted samples per event, triggered by precipitation measurements. This approach is more effective and efficient than simply increasing overall sampling frequency. It would enable the water utility to (1 analyze any relevant event and (2 limit median underestimation of peak concentrations to approximately 10%. We conclude with a generalized perspective on sampling optimization and argue that the assessment of short-term dynamics causing microbial peak loads initially requires increased sampling/analysis efforts, but can be optimized subsequently to account for limited resources. This offers water utilities and public health authorities systematic ways to evaluate and optimize their

  5. A new method for detecting interactions between the senses in event-related potentials

    DEFF Research Database (Denmark)

    Gondan, Matthias; Röder, B.

    2006-01-01

    Event-related potentials (ERPs) can be used in multisensory research to determine the point in time when different senses start to interact, for example, the auditory and the visual system. For this purpose, the ERP to bimodal stimuli (AV) is often compared to the sum of the ERPs to auditory (A......) and visual (V) stimuli: AV - (A + V). If the result is non-zero, this is interpreted as an indicator for multisensory interactions. Using this method, several studies have demonstrated auditory-visual interactions as early as 50 ms after stimulus onset. The subtraction requires that A, V, and AV do...... not contain common activity: This activity would be subtracted twice from one ERP and would, therefore, contaminate the result. In the present study, ERPs to unimodal, bimodal, and trimodal auditory, visual, and tactile stimuli (T) were recorded. We demonstrate that (T + TAV) - (TA + TV) is equivalent to AV...

  6. Study of the Convergence in State Estimators for LTI Systems with Event Detection

    Directory of Open Access Journals (Sweden)

    Juan C. Posada

    2016-01-01

    Full Text Available The methods frequently used to estimate the state of an LTI system require that the precise value of the output variable is known at all times, or at equidistant sampling times. In LTI systems, in which the output signal is measured through binary sensors (detectors, the traditional way of state observers design is not applicable even though the system has a complete observability matrix. This type of state observers design is known as passive. It is necessary, then, to introduce a new state estimation technique, which allows reckoning the state from the information of the variable’s crossing through a detector’s action threshold (switch. This paper seeks, therefore, to study the convergence in this type of estimators in finite time, allowing establishing, theoretically, whether some family of the proposed models can be estimated in a convergent way through the use of the estimation technique based on events.

  7. A multiplex microplatform for the detection of multiple DNA methylation events using gold-DNA affinity.

    Science.gov (United States)

    Sina, Abu Ali Ibn; Foster, Matthew Thomas; Korbie, Darren; Carrascosa, Laura G; Shiddiky, Muhammad J A; Gao, Jing; Dey, Shuvashis; Trau, Matt

    2017-10-07

    We report a new multiplexed strategy for the electrochemical detection of regional DNA methylation across multiple regions. Using the sequence dependent affinity of bisulfite treated DNA towards gold surfaces, the method integrates the high sensitivity of a micro-fabricated multiplex device comprising a microarray of gold electrodes, with the powerful multiplexing capability of multiplex-PCR. The synergy of this combination enables the monitoring of the methylation changes across several genomic regions simultaneously from as low as 500 pg μl -1 of DNA with no sequencing requirement.

  8. Fast joint detection-estimation of evoked brain activity in event-related FMRI using a variational approach

    Science.gov (United States)

    Chaari, Lotfi; Vincent, Thomas; Forbes, Florence; Dojat, Michel; Ciuciu, Philippe

    2013-01-01

    In standard within-subject analyses of event-related fMRI data, two steps are usually performed separately: detection of brain activity and estimation of the hemodynamic response. Because these two steps are inherently linked, we adopt the so-called region-based Joint Detection-Estimation (JDE) framework that addresses this joint issue using a multivariate inference for detection and estimation. JDE is built by making use of a regional bilinear generative model of the BOLD response and constraining the parameter estimation by physiological priors using temporal and spatial information in a Markovian model. In contrast to previous works that use Markov Chain Monte Carlo (MCMC) techniques to sample the resulting intractable posterior distribution, we recast the JDE into a missing data framework and derive a Variational Expectation-Maximization (VEM) algorithm for its inference. A variational approximation is used to approximate the Markovian model in the unsupervised spatially adaptive JDE inference, which allows automatic fine-tuning of spatial regularization parameters. It provides a new algorithm that exhibits interesting properties in terms of estimation error and computational cost compared to the previously used MCMC-based approach. Experiments on artificial and real data show that VEM-JDE is robust to model mis-specification and provides computational gain while maintaining good performance in terms of activation detection and hemodynamic shape recovery. PMID:23096056

  9. Microlensing events by Proxima Centauri in 2014 and 2016: Opportunities for mass determination and possible planet detection

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Kailash C.; Bond, Howard E.; Anderson, Jay [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Dominik, Martin, E-mail: ksahu@stsci.edu, E-mail: jayander@stsci.edu, E-mail: heb11@psu.edu, E-mail: md35@st-andrews.ac.uk [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS (United Kingdom)

    2014-02-20

    We have found that Proxima Centauri, the star closest to our Sun, will pass close to a pair of faint background stars in the next few years. Using Hubble Space Telescope (HST) images obtained in 2012 October, we determine that the passage close to a mag 20 star will occur in 2014 October (impact parameter 1.''6), and to a mag 19.5 star in 2016 February (impact parameter 0.''5). As Proxima passes in front of these stars, the relativistic deflection of light will cause shifts in the positions of the background stars of ∼0.5 and 1.5 mas, respectively, readily detectable by HST imaging, and possibly by Gaia and ground-based facilities such as the Very Large Telescope. Measurement of these astrometric shifts offers a unique and direct method to measure the mass of Proxima. Moreover, if Proxima has a planetary system, the planets may be detectable through their additional microlensing signals, although the probability of such detections is small. With astrometric accuracies of 0.03 mas (achievable with HST spatial scanning), centroid shifts caused by Jovian planets are detectable at separations of up to 2.''0 (corresponding to 2.6 AU at the distance of Proxima), and centroid shifts by Earth-mass planets are detectable within a small band of 8 mas (corresponding to 0.01 AU) around the source trajectories. Jovian planets within a band of about 28 mas (corresponding to 0.036 AU) around the source trajectories would produce a brightening of the source by >0.01 mag and could hence be detectable. Estimated timescales of the astrometric and photometric microlensing events due to a planet range from a few hours to a few days, and both methods would provide direct measurements of the planetary mass.

  10. [Event-related EEG potentials associated with error detection in psychiatric disorder: literature review].

    Science.gov (United States)

    Balogh, Lívia; Czobor, Pál

    2010-01-01

    Error-related bioelectric signals constitute a special subgroup of event-related potentials. Researchers have identified two evoked potential components to be closely related to error processing, namely error-related negativity (ERN) and error-positivity (Pe), and they linked these to specific cognitive functions. In our article first we give a brief description of these components, then based on the available literature, we review differences in error-related evoked potentials observed in patients across psychiatric disorders. The PubMed and Medline search engines were used in order to identify all relevant articles, published between 2000 and 2009. For the purpose of the current paper we reviewed publications summarizing results of clinical trials. Patients suffering from schizophrenia, anorexia nervosa or borderline personality disorder exhibited a decrease in the amplitude of error-negativity when compared with healthy controls, while in cases of depression and anxiety an increase in the amplitude has been observed. Some of the articles suggest specific personality variables, such as impulsivity, perfectionism, negative emotions or sensitivity to punishment to underlie these electrophysiological differences. Research in the field of error-related electric activity has come to the focus of psychiatry research only recently, thus the amount of available data is significantly limited. However, since this is a relatively new field of research, the results available at present are noteworthy and promising for future electrophysiological investigations in psychiatric disorders.

  11. A new computational method for the detection of horizontal gene transfer events.

    Science.gov (United States)

    Tsirigos, Aristotelis; Rigoutsos, Isidore

    2005-01-01

    In recent years, the increase in the amounts of available genomic data has made it easier to appreciate the extent by which organisms increase their genetic diversity through horizontally transferred genetic material. Such transfers have the potential to give rise to extremely dynamic genomes where a significant proportion of their coding DNA has been contributed by external sources. Because of the impact of these horizontal transfers on the ecological and pathogenic character of the recipient organisms, methods are continuously sought that are able to computationally determine which of the genes of a given genome are products of transfer events. In this paper, we introduce and discuss a novel computational method for identifying horizontal transfers that relies on a gene's nucleotide composition and obviates the need for knowledge of codon boundaries. In addition to being applicable to individual genes, the method can be easily extended to the case of clusters of horizontally transferred genes. With the help of an extensive and carefully designed set of experiments on 123 archaeal and bacterial genomes, we demonstrate that the new method exhibits significant improvement in sensitivity when compared to previously published approaches. In fact, it achieves an average relative improvement across genomes of between 11 and 41% compared to the Codon Adaptation Index method in distinguishing native from foreign genes. Our method's horizontal gene transfer predictions for 123 microbial genomes are available online at http://cbcsrv.watson.ibm.com/HGT/.

  12. Architecture design of the multi-functional wavelet-based ECG microprocessor for realtime detection of abnormal cardiac events.

    Science.gov (United States)

    Cheng, Li-Fang; Chen, Tung-Chien; Chen, Liang-Gee

    2012-01-01

    Most of the abnormal cardiac events such as myocardial ischemia, acute myocardial infarction (AMI) and fatal arrhythmia can be diagnosed through continuous electrocardiogram (ECG) analysis. According to recent clinical research, early detection and alarming of such cardiac events can reduce the time delay to the hospital, and the clinical outcomes of these individuals can be greatly improved. Therefore, it would be helpful if there is a long-term ECG monitoring system with the ability to identify abnormal cardiac events and provide realtime warning for the users. The combination of the wireless body area sensor network (BASN) and the on-sensor ECG processor is a possible solution for this application. In this paper, we aim to design and implement a digital signal processor that is suitable for continuous ECG monitoring and alarming based on the continuous wavelet transform (CWT) through the proposed architectures--using both programmable RISC processor and application specific integrated circuits (ASIC) for performance optimization. According to the implementation results, the power consumption of the proposed processor integrated with an ASIC for CWT computation is only 79.4 mW. Compared with the single-RISC processor, about 91.6% of the power reduction is achieved.

  13. Automated Detection of Obstructive Sleep Apnea Events from a Single-Lead Electrocardiogram Using a Convolutional Neural Network.

    Science.gov (United States)

    Urtnasan, Erdenebayar; Park, Jong-Uk; Joo, Eun-Yeon; Lee, Kyoung-Joung

    2018-04-23

    In this study, we propose a method for the automated detection of obstructive sleep apnea (OSA) from a single-lead electrocardiogram (ECG) using a convolutional neural network (CNN). A CNN model was designed with six optimized convolution layers including activation, pooling, and dropout layers. One-dimensional (1D) convolution, rectified linear units (ReLU), and max pooling were applied to the convolution, activation, and pooling layers, respectively. For training and evaluation of the CNN model, a single-lead ECG dataset was collected from 82 subjects with OSA and was divided into training (including data from 63 patients with 34,281 events) and testing (including data from 19 patients with 8571 events) datasets. Using this CNN model, a precision of 0.99%, a recall of 0.99%, and an F 1 -score of 0.99% were attained with the training dataset; these values were all 0.96% when the CNN was applied to the testing dataset. These results show that the proposed CNN model can be used to detect OSA accurately on the basis of a single-lead ECG. Ultimately, this CNN model may be used as a screening tool for those suspected to suffer from OSA.

  14. Secondary scintillation yield of xenon with sub-percent levels of CO2 additive for rare-event detection

    Science.gov (United States)

    Henriques, C. A. O.; Freitas, E. D. C.; Azevedo, C. D. R.; González-Díaz, D.; Mano, R. D. P.; Jorge, M. R.; Fernandes, L. M. P.; Monteiro, C. M. B.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carríon, J. V.; Cebrían, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Ferrario, P.; Ferreira, A. L.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monrabal, F.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D. R.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; NEXT Collaboration

    2017-10-01

    Xe-CO2 mixtures are important alternatives to pure xenon in Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification with applications in the important field of rare event detection such as directional dark matter, double electron capture and double beta decay detection. The addition of CO2 to pure xenon at the level of 0.05-0.1% can reduce significantly the scale of electron diffusion from 10 mm /√{m} to 2.5 mm /√{m}, with high impact on the discrimination efficiency of the events through pattern recognition of the topology of primary ionization trails. We have measured the electroluminescence (EL) yield of Xe-CO2 mixtures, with sub-percent CO2 concentrations. We demonstrate that the EL production is still high in these mixtures, 70% and 35% relative to that produced in pure xenon, for CO2 concentrations around 0.05% and 0.1%, respectively. The contribution of the statistical fluctuations in EL production to the energy resolution increases with increasing CO2 concentration, being smaller than the contribution of the Fano factor for concentrations below 0.1% CO2.

  15. Hospital staff should use more than one method to detect adverse events and potential adverse events: incident reporting, pharmacist surveillance and local real‐time record review may all have a place

    Science.gov (United States)

    Olsen, Sisse; Neale, Graham; Schwab, Kat; Psaila, Beth; Patel, Tejal; Chapman, E Jane; Vincent, Charles

    2007-01-01

    Background Over the past five years, in most hospitals in England and Wales, incident reporting has become well established but it remains unclear how well reports match clinical adverse events. International epidemiological studies of adverse events are based on retrospective, multi‐hospital case record review. In this paper the authors describe the use of incident reporting, pharmacist surveillance and local real‐time record review for the recognition of clinical risks associated with hospital inpatient care. Methodology Data on adverse events were collected prospectively on 288 patients discharged from adult acute medical and surgical units in an NHS district general hospital using incident reports, active surveillance of prescription charts by pharmacists and record review at time of discharge. Results Record review detected 26 adverse events (AEs) and 40 potential adverse events (PAEs) occurring during the index admission. In contrast, in the same patient group, incident reporting detected 11 PAEs and no AEs. Pharmacy surveillance found 10 medication errors all of which were PAEs. There was little overlap in the nature of events detected by the three methods. Conclusion The findings suggest that incident reporting does not provide an adequate assessment of clinical adverse events and that this method needs to be supplemented with other more systematic forms of data collection. Structured record review, carried out by clinicians, provides an important component of an integrated approach to identifying risk in the context of developing a safety and quality improvement programme. PMID:17301203

  16. Limits on light WIMPs with a 1 kg-scale germanium detector at 160 eVee physics threshold at the China Jinping Underground Laboratory

    Science.gov (United States)

    Yang, Li-Tao; Li, Hau-Bin; Yue, Qian; Kang, Ke-Jun; Cheng, Jian-Ping; Li, Yuan-Jing; Tsz-King Wong, Henry; Aǧartioǧlu, M.; An, Hai-Peng; Chang, Jian-Ping; Chen, Jing-Han; Chen, Yun-Hua; Deng, Zhi; Du, Qiang; Gong, Hui; He, Li; Hu, Jin-Wei; Hu, Qing-Dong; Huang, Han-Xiong; Jia, Li-Ping; Jiang, Hao; Li, Hong; Li, Jian-Min; Li, Jin; Li, Xia; Li, Xue-Qian; Li, Yu-Lan; Lin, Fong-Kay; Lin, Shin-Ted; Liu, Shu-Kui; Liu, Zhong-Zhi; Ma, Hao; Ma, Jing-Lu; Pan, Hui; Ren, Jie; Ruan, Xi-Chao; Sevda, B.; Sharma, Vivek; Shen, Man-Bin; Singh, Lakhwinder; Singh, Manoj Kumar; Tang, Chang-Jian; Tang, Wei-You; Tian, Yang; Wang, Ji-Min; Wang, Li; Wang, Qing; Wang, Yi; Wu, Shi-Yong; Wu, Yu-Cheng; Xing, Hao-Yang; Xu, Yin; Xue, Tao; Yang, Song-Wei; Yi, Nan; Yu, Chun-Xu; Yu, Hai-Jun; Yue, Jian-Feng; Zeng, Xiong-Hui; Zeng, Ming; Zeng, Zhi; Zhang, Yun-Hua; Zhao, Ming-Gang; Zhao, Wei; Zhou, Ji-Fang; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Zhong-Hua; CDEX Collaboration

    2018-01-01

    We report results of a search for light weakly interacting massive particle (WIMP) dark matter from the CDEX-1 experiment at the China Jinping Underground Laboratory (CJPL). Constraints on WIMP-nucleon spin-independent (SI) and spin-dependent (SD) couplings are derived with a physics threshold of 160 eVee, from an exposure of 737.1 kg-days. The SI and SD limits extend the lower reach of light WIMPs to 2 GeV and improve over our earlier bounds at WIMP mass less than 6 GeV. Supported by the National Key Research and Development Program of China (2017YFA0402200, 2017YFA0402201), the National Natural Science Foundation of China (11175099, 11275107, 11475117, 11475099, 11475092, 11675088), the National Basic Research Program of China (973 Program) (2010CB833006). We thank the support of grants from the Tsinghua University Initiative Scientific Research Program (20121088494, 20151080354) and the Academia Sinica Investigator Award 2011-15, contracts 103-2112-M-001-024 and 104-2112-M-001-038-MY3 from the Ministry of Science and Technology of Taiwan.

  17. Detecting kinematic boundary surfaces in phase space: particle mass measurements in SUSY-like events

    Science.gov (United States)

    Debnath, Dipsikha; Gainer, James S.; Kilic, Can; Kim, Doojin; Matchev, Konstantin T.; Yang, Yuan-Pao

    2017-06-01

    We critically examine the classic endpoint method for particle mass determination, focusing on difficult corners of parameter space, where some of the measurements are not independent, while others are adversely affected by the experimental resolution. In such scenarios, mass differences can be measured relatively well, but the overall mass scale remains poorly constrained. Using the example of the standard SUSY decay chain \\tilde{q}\\to {\\tilde{χ}}_2^0\\to \\tilde{ℓ}\\to {\\tilde{χ}}_1^0 , we demonstrate that sensitivity to the remaining mass scale parameter can be recovered by measuring the two-dimensional kinematical boundary in the relevant three-dimensional phase space of invariant masses squared. We develop an algorithm for detecting this boundary, which uses the geometric properties of the Voronoi tessellation of the data, and in particular, the relative standard deviation (RSD) of the volumes of the neighbors for each Voronoi cell in the tessellation. We propose a new observable, \\overline{Σ} , which is the average RSD per unit area, calculated over the hypothesized boundary. We show that the location of the \\overline{Σ} maximum correlates very well with the true values of the new particle masses. Our approach represents the natural extension of the one-dimensional kinematic endpoint method to the relevant three dimensions of invariant mass phase space.

  18. Detecting kinematic boundary surfaces in phase space and particle mass measurements in SUSY-like events

    CERN Document Server

    Debnath, Dipsikha; Kilic, Can; Kim, Doojin; Matchev, Konstantin T.; Yang, Yuan-Pao

    2017-06-19

    We critically examine the classic endpoint method for particle mass determination, focusing on difficult corners of parameter space, where some of the measurements are not independent, while others are adversely affected by the experimental resolution. In such scenarios, mass differences can be measured relatively well, but the overall mass scale remains poorly constrained. Using the example of the standard SUSY decay chain $\\tilde q\\to \\tilde\\chi^0_2\\to \\tilde \\ell \\to \\tilde \\chi^0_1$, we demonstrate that sensitivity to the remaining mass scale parameter can be recovered by measuring the two-dimensional kinematical boundary in the relevant three-dimensional phase space of invariant masses squared. We develop an algorithm for detecting this boundary, which uses the geometric properties of the Voronoi tessellation of the data, and in particular, the relative standard deviation (RSD) of the volumes of the neighbors for each Voronoi cell in the tessellation. We propose a new observable, $\\bar\\Sigma$, which is ...

  19. Calculating exclusion limits for weakly interacting massive particle direct detection experiments without background subtraction

    International Nuclear Information System (INIS)

    Green, Anne M.

    2002-01-01

    Competitive limits on the weakly interacting massive particle (WIMP) spin-independent scattering cross section are currently being produced by 76 Ge detectors originally designed to search for neutrinoless double beta decay, such as the Heidelberg-Moscow and IGEX experiments. In the absence of background subtraction, limits on the WIMP interaction cross section are set by calculating the upper confidence limit on the theoretical event rate, given the observed event rate. The standard analysis technique involves calculating the 90% upper confidence limit on the number of events in each bin, and excluding any set of parameters (WIMP mass and cross section) which produces a theoretical event rate for any bin which exceeds the 90% upper confidence limit on the event rate for that bin. We show that, if there is more than one energy bin, this produces exclusion limits that are actually at a lower degree of confidence than 90%, and are hence erroneously tight. We formulate criteria which produce true 90% confidence exclusion limits in these circumstances, including calculating the individual bin confidence limit for which the overall probability that no bins exceed this confidence limit is 90% and calculating the 90% minimum confidence limit on the number of bins which exceed their individual bin 90% confidence limits. We then compare the limits on the WIMP cross section produced by these criteria with those found using the standard technique, using data from the Heidelberg-Moscow and IGEX experiments

  20. FIRST STUDY OF DARK MATTER PROPERTIES WITH DETECTED SOLAR GRAVITY MODES AND NEUTRINOS

    Energy Technology Data Exchange (ETDEWEB)

    Turck-Chieze, S.; Garcia, R. A. [CEA/DSM/IRFU/SAp-AIM, CE Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette (France); Lopes, I. [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ballot, J. [Institut de Recherche en Astrophysique et Planetologie, CNRS, 14 avenue Edouard Belin and Universite de Toulouse, UPS-OMP, IRAP, 31400 Toulouse (France); Couvidat, S. [W.W. Hansen. E. P. L., Stanford University, Stanford, CA 94305 (United States); Mathur, S. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Salabert, D. [CNRS, Observatoire de la Cote d' Azur, Universite de Nice Sophia-Antipolis, BP 4229, 06304 Nice Cedex 4 (France); Silk, J., E-mail: Sylvaine.Turck-Chieze@cea.fr [UPMC-CNRS, UMR7095, Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2012-02-10

    We derive new limits on the cold dark matter properties for weakly interacting massive particles (WIMPs), potentially trapped in the solar core by using for the first time the central temperature constrained by boron neutrinos and the central density constrained by the dipolar gravity modes detected with the Global Oscillations at Low Frequency/Solar Helioseismic Observatory instrument. These detections disfavor the presence of non-annihilating WIMPs for masses {<=}10 GeV and spin dependent cross-sections >5 Multiplication-Sign 10{sup -36} cm{sup 2} in the solar core but cannot constrain WIMP annihilation models. We suggest that in the coming years helio- and asteroseismology will provide complementary probes of dark matter.

  1. Multiple-Threshold Event Detection and Other Enhancements to the Virtual Seismologist (VS) Earthquake Early Warning Algorithm

    Science.gov (United States)

    Fischer, M.; Caprio, M.; Cua, G. B.; Heaton, T. H.; Clinton, J. F.; Wiemer, S.

    2009-12-01

    The Virtual Seismologist (VS) algorithm is a Bayesian approach to earthquake early warning (EEW) being implemented by the Swiss Seismological Service at ETH Zurich. The application of Bayes’ theorem in earthquake early warning states that the most probable source estimate at any given time is a combination of contributions from a likelihood function that evolves in response to incoming data from the on-going earthquake, and selected prior information, which can include factors such as network topology, the Gutenberg-Richter relationship or previously observed seismicity. The VS algorithm was one of three EEW algorithms involved in the California Integrated Seismic Network (CISN) real-time EEW testing and performance evaluation effort. Its compelling real-time performance in California over the last three years has led to its inclusion in the new USGS-funded effort to develop key components of CISN ShakeAlert, a prototype EEW system that could potentially be implemented in California. A significant portion of VS code development was supported by the SAFER EEW project in Europe. We discuss recent enhancements to the VS EEW algorithm. We developed and continue to test a multiple-threshold event detection scheme, which uses different association / location approaches depending on the peak amplitudes associated with an incoming P pick. With this scheme, an event with sufficiently high initial amplitudes can be declared on the basis of a single station, maximizing warning times for damaging events for which EEW is most relevant. Smaller, non-damaging events, which will have lower initial amplitudes, will require more picks to be declared an event to reduce false alarms. This transforms the VS codes from a regional EEW approach reliant on traditional location estimation (and it requirement of at least 4 picks as implemented by the Binder Earthworm phase associator) to a hybrid on-site/regional approach capable of providing a continuously evolving stream of EEW

  2. Atomic-scale nanoindentation: detection and identification of single glide events in three dimensions by force microscopy

    International Nuclear Information System (INIS)

    Egberts, P; Bennewitz, R

    2011-01-01

    Indentation experiments on the nanometre scale have been performed by means of atomic force microscopy in ultra-high vacuum on KBr(100) surfaces. The surfaces yield in the form of discrete surface displacements with a typical length scale of 1 A. These surface displacements are detected in both normal and lateral directions. Measurement of the lateral tip displacement requires a load-dependent calibration due to the load dependence of the effective lateral compliance. Correlation of the lateral and normal displacements for each glide event allow identification of the activated slip system. The results are discussed in terms of the resolved shear stress in indentation experiments and of typical results in atomistic simulations of nanometre-scale indentation.

  3. Dark matter and its detection

    International Nuclear Information System (INIS)

    Bi Xiaojun; Qin Bo

    2011-01-01

    We first explain the concept of dark matter,then review the history of its discovery and the evidence of its existence. We describe our understanding of the nature of dark matter particles, the popular dark matter models,and why the weakly interacting massive particles (called WIMPs) are the most attractive candidates for dark matter. Then we introduce the three methods of dark matter detection: colliders, direct detection and indirect detection. Finally, we review the recent development of dark matter detection, including the new results from DAMA, CoGent, PAMELA, ATIC and Fermi. (authors)

  4. Adverse Events Associated with Hospitalization or Detected through the RAI-HC Assessment among Canadian Home Care Clients

    Science.gov (United States)

    Doran, Diane; Hirdes, John P.; Blais, Régis; Baker, G. Ross; Poss, Jeff W.; Li, Xiaoqiang; Dill, Donna; Gruneir, Andrea; Heckman, George; Lacroix, Hélène; Mitchell, Lori; O'Beirne, Maeve; Foebel, Andrea; White, Nancy; Qian, Gan; Nahm, Sang-Myong; Yim, Odilia; Droppo, Lisa; McIsaac, Corrine

    2013-01-01

    Background: The occurrence of adverse events (AEs) in care settings is a patient safety concern that has significant consequences across healthcare systems. Patient safety problems have been well documented in acute care settings; however, similar data for clients in home care (HC) settings in Canada are limited. The purpose of this Canadian study was to investigate AEs in HC, specifically those associated with hospitalization or detected through the Resident Assessment Instrument for Home Care (RAI-HC). Method: A retrospective cohort design was used. The cohort consisted of HC clients from the provinces of Nova Scotia, Ontario, British Columbia and the Winnipeg Regional Health Authority. Results: The overall incidence rate of AEs associated with hospitalization ranged from 6% to 9%. The incidence rate of AEs determined from the RAI-HC was 4%. Injurious falls, injuries from other than fall and medication-related events were the most frequent AEs associated with hospitalization, whereas new caregiver distress was the most frequent AE identified through the RAI-HC. Conclusion: The incidence of AEs from all sources of data ranged from 4% to 9%. More resources are needed to target strategies for addressing safety risks in HC in a broader context. Tools such as the RAI-HC and its Clinical Assessment Protocols, already available in Canada, could be very useful in the assessment and management of HC clients who are at safety risk. PMID:23968676

  5. Detection and discrimination of maintenance and de novo CpG methylation events using MethylBreak.

    Science.gov (United States)

    Hsu, William; Mercado, Augustus T; Hsiao, George; Yeh, Jui-Ming; Chen, Chung-Yung

    2017-05-15

    Understanding the principles governing the establishment and maintenance activities of DNA methyltransferases (DNMTs) can help in the development of predictive biomarkers associated with genetic disorders and diseases. A detection system was developed that distinguishes and quantifies methylation events using methylation-sensitive endonucleases and molecular beacon technology. MethylBreak (MB) is a 22-mer oligonucleotide with one hemimethylated and two unmethylated CpG sites, which are also recognition sites for Sau96I and SacII, and is attached to a fluorophore and a quencher. Maintenance methylation was quantified by fluorescence emission due to the digestion of SacII when the hemimethylated CpG site is methylated, which inhibits Sau96I cleavage. The signal difference between SacII digestion of both MB substrate and maintenance methylated MB corresponds to de novo methylation event. Our technology successfully discriminated and measured both methylation activities at different concentrations of MB and achieved a high correlation coefficient of R 2 =0.997. Additionally, MB was effectively applied to normal and cancer cell lines and in the analysis of enzymatic kinetics and RNA inhibition of recombinant human DNMT1. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Method and device for detecting impact events on a security barrier which includes a hollow rebar allowing insertion and removal of an optical fiber

    Science.gov (United States)

    Pies, Ross E.

    2016-03-29

    A method and device for the detection of impact events on a security barrier. A hollow rebar is farmed within a security barrier, whereby the hollow rebar is completely surrounded by the security barrier. An optical fiber passes through the interior of the hollow rebar. An optical transmitter and an optical receiver are both optically connected to the optical fiber and connected to optical electronics. The optical electronics are configured to provide notification upon the detection of an impact event at the security barrier based on the detection of disturbances within the optical fiber.

  7. Simulation of argon response and light detection in the DarkSide-50 dual phase TPC

    Energy Technology Data Exchange (ETDEWEB)

    Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Asner, D. M.; Back, H. O.; Biery, K.; Bocci, V.; Bonfini, G.; Bonivento, W.; Bossa, M.; Bottino, B.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Caravati, M.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cataudella, V.; Cavalcante, P.; Chepurnov, A.; Cicalò, C.; Cocco, A. G.; Covone, G.; D' Angelo, D.; D' Incecco, M.; Davini, S.; de Candia, A.; Cecco, S. De; Deo, M. De; Filippis, G. De; Vincenzi, M. De; Derbin, A. V.; Rosa, G. De; Devoto, A.; Eusanio, F. Di; Pietro, G. Di; Dionisi, C.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Giagu, S.; Giganti, C.; Giovanetti, G. K.; Goretti, A. M.; Granato, F.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K.; Hughes, D.; Humble, P.; Hungerford, E. V.; Ianni, An.; James, I.; Johnson, T. N.; Keeter, K.; Kendziora, C. L.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Loer, B.; Longo, G.; Ma, Y.; Machado, A. A.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Martoff, C. J.; Meyers, P. D.; Milincic, R.; Monte, A.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Agasson, A. Navrer; Oleinik, A.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Pelczar, K.; Pelliccia, N.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Razeti, M.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Rescigno, M.; Riffard, Q.; Romani, A.; Rossi, B.; Rossi, N.; Sablone, D.; Sands, W.; Sanfilippo, S.; Savarese, C.; Schlitzer, B.; Segreto, E.; Semenov, D. A.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Verducci, M.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xiao, X.; Yang, C.; Ye, Z.; Zhu, C.; Zuzel, G.

    2017-10-01

    Geant4-based Monte Carlo package named G4DS has been developed to simulate the response of DarkSide-50, an experiment operating since 2013 at LNGS, designed to detect WIMP interactions in liquid argon. In the process of WIMP searches, DarkSide-50 has achieved two fundamental milestones: the rejection of electron recoil background with a power of ~10^7, using the pulse shape discrimination technique, and the measurement of the residual 39Ar contamination in underground argon, ~3 orders of magnitude lower with respect to atmospheric argon.

  8. Glaucoma progression detection by retinal nerve fiber layer measurement using scanning laser polarimetry: event and trend analysis.

    Science.gov (United States)

    Moon, Byung Gil; Sung, Kyung Rim; Cho, Jung Woo; Kang, Sung Yong; Yun, Sung-Cheol; Na, Jung Hwa; Lee, Youngrok; Kook, Michael S

    2012-06-01

    To evaluate the use of scanning laser polarimetry (SLP, GDx VCC) to measure the retinal nerve fiber layer (RNFL) thickness in order to evaluate the progression of glaucoma. Test-retest measurement variability was determined in 47 glaucomatous eyes. One eye each from 152 glaucomatous patients with at least 4 years of follow-up was enrolled. Visual field (VF) loss progression was determined by both event analysis (EA, Humphrey guided progression analysis) and trend analysis (TA, linear regression analysis of the visual field index). SLP progression was defined as a reduction of RNFL exceeding the predetermined repeatability coefficient in three consecutive exams, as compared to the baseline measure (EA). The slope of RNFL thickness change over time was determined by linear regression analysis (TA). Twenty-two eyes (14.5%) progressed according to the VF EA, 16 (10.5%) by VF TA, 37 (24.3%) by SLP EA and 19 (12.5%) by SLP TA. Agreement between VF and SLP progression was poor in both EA and TA (VF EA vs. SLP EA, k = 0.110; VF TA vs. SLP TA, k = 0.129). The mean (±standard deviation) progression rate of RNFL thickness as measured by SLP TA did not significantly differ between VF EA progressors and non-progressors (-0.224 ± 0.148 µm/yr vs. -0.218 ± 0.151 µm/yr, p = 0.874). SLP TA and EA showed similar levels of sensitivity when VF progression was considered as the reference standard. RNFL thickness as measurement by SLP was shown to be capable of detecting glaucoma progression. Both EA and TA of SLP showed poor agreement with VF outcomes in detecting glaucoma progression.

  9. Pharyngeal pH alone is not reliable for the detection of pharyngeal reflux events: A study with oesophageal and pharyngeal pH-impedance monitoring

    Science.gov (United States)

    Desjardin, Marie; Roman, Sabine; des Varannes, Stanislas Bruley; Gourcerol, Guillaume; Coffin, Benoit; Ropert, Alain; Mion, François

    2013-01-01

    Background Pharyngeal pH probes and pH-impedance catheters have been developed for the diagnosis of laryngo-pharyngeal reflux. Objective To determine the reliability of pharyngeal pH alone for the detection of pharyngeal reflux events. Methods 24-h pH-impedance recordings performed in 45 healthy subjects with a bifurcated probe for detection of pharyngeal and oesophageal reflux events were reviewed. Pharyngeal pH drops to below 4 and 5 were analysed for the simultaneous occurrence of pharyngeal reflux, gastro-oesophageal reflux, and swallows, according to impedance patterns. Results Only 7.0% of pharyngeal pH drops to below 5 identified with impedance corresponded to pharyngeal reflux, while 92.6% were related to swallows and 10.2 and 13.3% were associated with proximal and distal gastro-oesophageal reflux events, respectively. Of pharyngeal pH drops to below 4, 13.2% were related to pharyngeal reflux, 87.5% were related to swallows, and 18.1 and 21.5% were associated with proximal and distal gastro-oesophageal reflux events, respectively. Conclusions This study demonstrates that pharyngeal pH alone is not reliable for the detection of pharyngeal reflux and that adding distal oesophageal pH analysis is not helpful. The only reliable analysis should take into account impedance patterns demonstrating the presence of pharyngeal reflux event preceded by a distal and proximal reflux event within the oesophagus. PMID:24917995

  10. A measurement of the muon number in showers using inclined events detected at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Rodriguez G.

    2013-06-01

    Full Text Available The average muon content of measured showers with zenith angles between 62∘ and 80∘ detected at the Pierre Auger Observatory is obtained as a function of shower energy using a reconstruction method specifically designed for inclined showers and the hybrid character of the detector. The reconstruction of inclined showers relies on a comparison between the measured signals at ground and reference patterns at ground level from which an overall normalization factor is obtained. Since inclined showers are dominated by muons this factor gives the relative muon size. It can be calibrated using a subsample of showers simultaneously recorded with the fluorescence detector (FD and the surface detector (SD which provides an independent calorimetric measurement of the energy. The muon size obtained for each shower becomes a measurement of the relative number of muons with respect to the reference distributions. The precision of the measurement is assessed using simulated events which are reconstructed using exactly the same procedure. We compare the relative number of muons versus energy as obtained to simulations. Proton simulations with QGSJETII show a factor of 2.13 ± 0.04(stat ± 0.11(sys at 1019eV without significant variations in the energy range explored between 4 × 1018eV to 7 × 1019eV. We find that none of the current shower models, neither for proton nor for iron primaries, are able to predict as many muons as are observed.

  11. Waveform correlation and coherence of short-period seismic noise within Gauribidanur array with implications for event detection

    International Nuclear Information System (INIS)

    Bhadauria, Y.S.; Arora, S.K.

    1995-01-01

    In continuation with our effort to model the short-period micro seismic noise at the seismic array at Gauribidanur (GBA), we have examined in detail time-correlation and spectral coherence of the noise field within the array space. This has implications of maximum possible improvement in signal-to-noise ratio (SNR) relevant to event detection. The basis of this study is about a hundred representative wide-band noise samples collected from GBA throughout the year 1992. Both time-structured correlation as well as coherence of the noise waveforms are found to be practically independent of the inter element distances within the array, and they exhibit strong temporal and spectral stability. It turns out that the noise is largely incoherent at frequencies ranging upwards from 2 Hz; the coherency coefficient tends to increase in the lower frequency range attaining a maximum of 0.6 close to 0.5 Hz. While the maximum absolute cross-correlation also diminishes with increasing frequency, the zero-lag cross-correlation is found to be insensitive to frequency filtering regardless of the pass band. An extremely small value of -0.01 of the zero-lag correlation and a comparatively higher year-round average estimate at 0.15 of the maximum absolute time-lagged correlation yields an SNR improvement varying between a probable high of 4.1 and a low of 2.3 for the full 20-element array. 19 refs., 6 figs

  12. Deficits in cue detection underlie event-based prospective memory impairment in major depression: an eye tracking study.

    Science.gov (United States)

    Chen, Siyi; Zhou, Renlai; Cui, Hong; Chen, Xinyin

    2013-10-30

    This study examined the cue detection in the non-focal event-based prospective memory (PM) of individuals with and without a major depressive disorder using behavioural and eye tracking assessments. The participants were instructed to search on each trial for a different target stimulus that could be present or absent and to make prospective responses to the cue object. PM tasks included cue only and target plus cue, whereas ongoing tasks included target only and distracter only. The results showed that a) participants with depression performed more poorly than those without depression in PM; b) participants with depression showed more fixations and longer total and average fixation durations in both ongoing and PM conditions; c) participants with depression had lower scores on accuracy in target-plus-cue trials than in cue-only trials and had a higher gaze rate of targets on hits and misses in target-plus-cue trials than did those without depression. The results indicate that the state of depression may impair top-down cognitive control function, which in turn results in particular deficits in the engagement of monitoring for PM cues. Copyright © 2013. Published by Elsevier Ireland Ltd.

  13. 1.3 mm WAVELENGTH VLBI OF SAGITTARIUS A*: DETECTION OF TIME-VARIABLE EMISSION ON EVENT HORIZON SCALES

    International Nuclear Information System (INIS)

    Fish, Vincent L.; Doeleman, Sheperd S.; Beaudoin, Christopher; Bolin, David E.; Rogers, Alan E. E.; Blundell, Ray; Gurwell, Mark A.; Moran, James M.; Primiani, Rurik; Bower, Geoffrey C.; Plambeck, Richard; Chamberlin, Richard; Freund, Robert; Friberg, Per; Honma, Mareki; Oyama, Tomoaki; Inoue, Makoto; Krichbaum, Thomas P.; Lamb, James; Marrone, Daniel P.

    2011-01-01

    Sagittarius A*, the ∼4 x 10 6 M sun black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A* using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.

  14. Cryogenic dark matter search (CDMS II): Application of neural networks and wavelets to event analysis

    Energy Technology Data Exchange (ETDEWEB)

    Attisha, Michael J. [Brown U.

    2006-01-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to search for dark matter in the form of Weakly Interacting Massive Particles (WIMPs) via their elastic scattering interactions with nuclei. This dissertation presents the CDMS detector technology and the commissioning of two towers of detectors at the deep underground site in Soudan, Minnesota. CDMS detectors comprise crystals of Ge and Si at temperatures of 20 mK which provide ~keV energy resolution and the ability to perform particle identification on an event by event basis. Event identification is performed via a two-fold interaction signature; an ionization response and an athermal phonon response. Phonons and charged particles result in electron recoils in the crystal, while neutrons and WIMPs result in nuclear recoils. Since the ionization response is quenched by a factor ~ 3(2) in Ge(Si) for nuclear recoils compared to electron recoils, the relative amplitude of the two detector responses allows discrimination between recoil types. The primary source of background events in CDMS arises from electron recoils in the outer 50 µm of the detector surface which have a reduced ionization response. We develop a quantitative model of this ‘dead layer’ effect and successfully apply the model to Monte Carlo simulation of CDMS calibration data. Analysis of data from the two tower run March-August 2004 is performed, resulting in the world’s most sensitive limits on the spin-independent WIMP-nucleon cross-section, with a 90% C.L. upper limit of 1.6 × 10-43 cm2 on Ge for a 60 GeV WIMP. An approach to performing surface event discrimination using neural networks and wavelets is developed. A Bayesian methodology to classifying surface events using neural networks is found to provide an optimized method based on minimization of the expected dark matter limit. The discrete wavelet analysis of CDMS phonon pulses improves surface event discrimination in conjunction with the neural

  15. Low energy recoil detection with a spherical proportional counter

    Science.gov (United States)

    Savvidis, I.; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2018-01-01

    We present results for the detection of low energy nuclear recoils in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An 241Am-9Be fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the keV energy region was measured by observing the 5.9 keV line of a 55Fe X-ray source, with energy resolution of 10% (σ). The toolkit GEANT4 was used to simulate the irradiation of the detector by an 241Am-9Be source, while SRIM was used to calculate the Ionization Quenching Factor (IQF), the simulation results are compared with the measurements. The potential of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searches (via coherent elastic scattering).

  16. Is detection of adverse events affected by record review methodology? an evaluation of the "Harvard Medical Practice Study" method and the "Global Trigger Tool".

    Science.gov (United States)

    Unbeck, Maria; Schildmeijer, Kristina; Henriksson, Peter; Jürgensen, Urban; Muren, Olav; Nilsson, Lena; Pukk Härenstam, Karin

    2013-04-15

    There has been a theoretical debate as to which retrospective record review method is the most valid, reliable, cost efficient and feasible for detecting adverse events. The aim of the present study was to evaluate the feasibility and capability of two common retrospective record review methods, the "Harvard Medical Practice Study" method and the "Global Trigger Tool" in detecting adverse events in adult orthopaedic inpatients. We performed a three-stage structured retrospective record review process in a random sample of 350 orthopaedic admissions during 2009 at a Swedish university hospital. Two teams comprised each of a registered nurse and two physicians were assigned, one to each method. All records were primarily reviewed by registered nurses. Records containing a potential adverse event were forwarded to physicians for review in stage 2. Physicians made an independent review regarding, for example, healthcare causation, preventability and severity. In the third review stage all adverse events that were found with the two methods together were compared and all discrepancies after review stage 2 were analysed. Events that had not been identified by one of the methods in the first two review stages were reviewed by the respective physicians. Altogether, 160 different adverse events were identified in 105 (30.0%) of the 350 records with both methods combined. The "Harvard Medical Practice Study" method identified 155 of the 160 (96.9%, 95% CI: 92.9-99.0) adverse events in 104 (29.7%) records compared with 137 (85.6%, 95% CI: 79.2-90.7) adverse events in 98 (28.0%) records using the "Global Trigger Tool". Adverse events "causing harm without permanent disability" accounted for most of the observed difference. The overall positive predictive value for criteria and triggers using the "Harvard Medical Practice Study" method and the "Global Trigger Tool" was 40.3% and 30.4%, respectively. More adverse events were identified using the "Harvard Medical Practice Study

  17. Detection of Healthcare-Related Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Transmission Events Using Combined Genetic and Phenotypic Epidemiology.

    Directory of Open Access Journals (Sweden)

    Anne F Voor In 't Holt

    Full Text Available Since the year 2000 there has been a sharp increase in the prevalence of healthcare-related infections caused by extended-spectrum beta-lactamase (ESBL-producing Escherichia coli. However, the high community prevalence of ESBL-producing E. coli isolates means that many E. coli typing techniques may not be suitable for detecting E. coli transmission events. Therefore, we investigated if High-throughput MultiLocus Sequence Typing (HiMLST and/or Raman spectroscopy were suitable techniques for detecting recent E. coli transmission events.This study was conducted from January until December 2010 at Erasmus University Medical Center, Rotterdam, the Netherlands. Isolates were typed using HiMLST and Raman spectroscopy. A genetic cluster was defined as two or more patients carrying identical isolates. We used predefined definitions for epidemiological relatedness to assess healthcare-related transmission.We included 194 patients; strains of 112 patients were typed using HiMLST and strains of 194 patients were typed using Raman spectroscopy. Raman spectroscopy identified 16 clusters while HiMLST identified 10 clusters. However, no healthcare-related transmission events were detected. When combining data from both typing techniques, we identified eight clusters (n = 34 patients, as well as 78 patients with a non-cluster isolate. However, we could not detect any healthcare-related transmission in these 8 clusters.Although clusters were genetically detected using HiMLST and Raman spectroscopy, no definite epidemiological relationships could be demonstrated which makes the possibility of healthcare-related transmission events highly unlikely. Our results suggest that typing of ESBL-producing E. coli using HiMLST and/or Raman spectroscopy is not helpful in detecting E. coli healthcare-related transmission events.

  18. Multichannel linear descriptors analysis for event-related EEG of vascular dementia patients during visual detection task.

    Science.gov (United States)

    Lou, Wutao; Xu, Jin; Sheng, Hengsong; Zhao, Songzhen

    2011-11-01

    Multichannel EEG recorded in a task condition could contain more information about cognition. However, that has not been widely investigated in the vascular-dementia (VaD)- related studies. The purpose of this study was to explore the differences of brain functional states between VaD patients and normal controls while performing a detection task. Three multichannel linear descriptors, i.e. spatial complexity (Ω), field strength (Σ) and frequency of field changes (Φ), were applied to analyse four frequency bands (delta, theta, alpha and beta) of multichannel event-related EEG signals for 12 VaD patients (mean age ± SD: 69.25 ± 10.56 years ; MMSE score ± SD: 22.58 ± 4.42) and 12 age-matched healthy subjects (mean age ± SD: 67.17 ± 5.97 years ; MMSE score ± SD: 29.08 ± 0.9). The correlations between the three measures and MMSE scores were also analysed. VaD patients showed a significant higher Ω value in the delta (p = 0.013) and theta (p = 0.021) frequency bands, a lower Σ value (p = 0.011) and a higher Φ (p = 0.008) value in the delta frequency band compared with normal controls. The MMSE scores were negatively correlated with the Ω (r = -0.52, p = 0.01) and Φ (r = -0.47, p = 0.02) values in the delta frequency band. The results indicated the VaD patients presented a reduction of synchronization in the slow frequency band during target detection, and suggested more neurons might be activated in VaD patients compared with normal controls. The Ω and Φ measures in the delta frequency band might be used to evaluate the degree of cognitive dysfunction. The multichannel linear descriptors are promising measures to reveal the differences in brain functions between VaD patients and normal subjects, and could potentially be used to evaluate the degree of cognitive dysfunction in VaD patients. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Effectiveness of pacemaker tele-monitoring on quality of life, functional capacity, event detection and workload: The PONIENTE trial.

    Science.gov (United States)

    Lopez-Villegas, Antonio; Catalan-Matamoros, Daniel; Robles-Musso, Emilio; Peiro, Salvador

    2016-11-01

    The purpose of the present study was to assess the effectiveness of the remote monitoring (RM) of older adults with pacemakers on health-related quality of life, functional capacity, feasibility, reliability and safety. The PONIENTE study is a controlled, non-randomized, non-blinded clinical trial, with data collection carried out during the pre-implant stage and after 12 months. Between October of 2012 and November of 2013, 82 patients were assigned to either a remote monitoring group (n = 30) or a conventional hospital monitoring (HM) group (n = 52). The EuroQol-5D (EQ-5D) and the Duke Activity Status Index were used to measure health-related quality of life and functional capacity, respectively. Baseline characteristics and number of hospital visits were also analyzed. The baseline characteristics of the two study groups were similar for both the EQ-5D (RM 0.74, HM 0.67; P = 0.404) and the Duke Activity Status Index (RM 21.42, HM 19.95; P = 0.272). At the 12-month follow up, the EQ-5D utility score was improved for both groups (RM 0.91, HM 0.81; P = 0.154), unlike the EQ-5D Visual Analog Scale (P = 0.043). The Duke Activity Status Index score was similar to the baseline score. The number of in-hospital visits was 27% lower (3 vs 4; P pacemakers in older adults is an equivalent option to hospital monitoring, in terms of health-related quality of life and functional capacity. Furthermore, it allows for the early detection of clinical and pacemaker-related adverse events, and significantly reduces the number of in-hospital visits. Geriatr Gerontol Int 2016; 16: 1188-1195. © 2015 Japan Geriatrics Society.

  20. A comment on Farwell : brain fingerprinting: a comprehensive tutorial review of detection of concealed information with event-related brain potentials

    NARCIS (Netherlands)

    Meijer, E.H.; Ben-Shakhar, G.; Verschuere, B.; Donchin, E.

    2013-01-01

    In a recent issue of Cognitive Neurodynamics Farwell (Cogn Neurodyn 6:115-154, 2012) published a comprehensive tutorial review of the use of Event Related Brain Potentials (ERP) in the detection of concealed information. Farwell’s review covered much of his own work employing his ‘‘brain

  1. On-line detection of apnea/hypopnea events using SpO2 signal: a rule-based approach employing binary classifier models.

    Science.gov (United States)

    Koley, Bijoy Laxmi; Dey, Debangshu

    2014-01-01

    This paper presents an online method for automatic detection of apnea/hypopnea events, with the help of oxygen saturation (SpO2) signal, measured at fingertip by Bluetooth nocturnal pulse oximeter. Event detection is performed by identifying abnormal data segments from the recorded SpO2 signal, employing a binary classifier model based on a support vector machine (SVM). Thereafter the abnormal segment is further analyzed to detect different states within the segment, i.e., steady, desaturation, and resaturation, with the help of another SVM-based binary ensemble classifier model. Finally, a heuristically obtained rule-based system is used to identify the apnea/hypopnea events from the time-sequenced decisions of these classifier models. In the developmental phase, a set of 34 time domain-based features was extracted from the segmented SpO2 signal using an overlapped windowing technique. Later, an optimal set of features was selected on the basis of recursive feature elimination technique. A total of 34 subjects were included in the study. The results show average event detection accuracies of 96.7% and 93.8% for the offline and the online tests, respectively. The proposed system provides direct estimation of the apnea/hypopnea index with the help of a relatively inexpensive and widely available pulse oximeter. Moreover, the system can be monitored and accessed by physicians through LAN/WAN/Internet and can be extended to deploy in Bluetooth-enabled mobile phones.

  2. Automatic, ECG-based detection of autonomic arousals and their association with cortical arousals, leg movements, and respiratory events in sleep

    DEFF Research Database (Denmark)

    Olsen, Mads; Schneider, Logan Douglas; Cheung, Joseph

    2018-01-01

    The current definition of sleep arousals neglects to address the diversity of arousals and their systemic cohesion. Autonomic arousals (AA) are autonomic activations often associated with cortical arousals (CA), but they may also occur in isolation in relation to a respiratory event, a leg movement...... event or spontaneously, without any other physiological associations. AA should be acknowledged as essential events to understand and explore the systemic implications of arousals. We developed an automatic AA detection algorithm based on intelligent feature selection and advanced machine learning using...... or respiratory events. This indicates that most FP constitute autonomic activations that are indistinguishable from those with cortical cohesion. The proposed algorithm provides an automatic system trained in a clinical environment, which can be utilized to analyse the systemic and clinical impacts of arousals....

  3. Bulk and surface event identification in p-type germanium detectors

    Science.gov (United States)

    Yang, L. T.; Li, H. B.; Wong, H. T.; Agartioglu, M.; Chen, J. H.; Jia, L. P.; Jiang, H.; Li, J.; Lin, F. K.; Lin, S. T.; Liu, S. K.; Ma, J. L.; Sevda, B.; Sharma, V.; Singh, L.; Singh, M. K.; Singh, M. K.; Soma, A. K.; Sonay, A.; Yang, S. W.; Wang, L.; Wang, Q.; Yue, Q.; Zhao, W.

    2018-04-01

    The p-type point-contact germanium detectors have been adopted for light dark matter WIMP searches and the studies of low energy neutrino physics. These detectors exhibit anomalous behavior to events located at the surface layer. The previous spectral shape method to identify these surface events from the bulk signals relies on spectral shape assumptions and the use of external calibration sources. We report an improved method in separating them by taking the ratios among different categories of in situ event samples as calibration sources. Data from CDEX-1 and TEXONO experiments are re-examined using the ratio method. Results are shown to be consistent with the spectral shape method.

  4. Study of new germanium bolometers with interleaved concentric electrodes for non-baryonic cold dark matter direct detection in the Edelweiss-II experiment

    International Nuclear Information System (INIS)

    Domange, J.

    2011-09-01

    EDELWEISS is a direct non-baryonic cold dark matter detection experiment in the form of weakly interacting massive particles (also known as WIMPs), which currently constitute the most popular candidates to account for the missing mass in the Universe. To this purpose, EDELWEISS uses germanium bolometers at cryogenic temperature (20 mK approximately) in the Underground Laboratory of Modane (LSM) at the French-Italian border. Since 2008, a new type of detector is operated, equipped with concentric electrodes to optimize the rejection of surface events (coplanar-grid detectors). This thesis work is divided into several research orientations. First, we carried out measurements concerning charge collection in the crystals. The velocity laws of the carriers (electrons and holes) have been determined in germanium at 20 mK in the orientation, and a complete study of charge sharing has been done, including an evaluation of the transport anisotropy and of the straggling of the carriers. These results lead to a better understanding of the inner properties of the EDELWEISS detectors. Then, studies relating to the improvement of the performances were carried out. In particular, we have optimized the space-charge cancellation procedure in the crystals and improved the passive rejection of surface events (β). The fiducial volume of the detectors has been evaluated using two X-ray lines from cosmically activated radionuclides: 68 Ge and 65 Zn. Finally, an exhaustive study of the low energy spectra has been carried out, which makes it possible to develop a systematic analysis method for the search of low-mass WIMPs in EDELWEISS. (author)

  5. Study of a spherical gaseous detector for research of rare events at low energy threshold

    International Nuclear Information System (INIS)

    Dastgheibi-Fard, Ali

    2014-01-01

    The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a novel type of a particle detector, with a broad range of applications. Its main features include a very low energy threshold which is independent of the volume (due to its very low capacitance), a good energy resolution, robustness and a single detection readout channel. SEDINE, a low background detector installed at the underground site of Laboratoire Souterrain de Modane is currently being operated and aims at measuring events at a very low energy threshold, around 40 eV. The sensitivity for the rare events detection at low energy is correlated to the detector background and to the decreasing the level of energy threshold, which was the main point of this thesis. A major effort has been devoted to the operating of the experimental detector. Several detection parameters were optimized: the electric field homogeneity in the sphere, keeping clear of sparks, the electronic noise level and the leak rate of the detector. The detector is optimized for operation with a high pressure stable gain. The modification of the shield, cleanings of the detector and the addition of an anti-Radon tent have significantly reduced the background of SEDINE. Progress has increased the sensitivity of the detector at low energy up to a value comparable to the results other underground research experiences for the low mass WIMPs. We will present the results with a measured background in the region of keV, which has allowed us to show a competitive figure of exclusion for the production of light dark matter. (author) [fr

  6. The inert doublet model: a new archetype of WIMP dark matter?

    International Nuclear Information System (INIS)

    Tytgat, M Hg

    2008-01-01

    The Inert Doublet Model (IDM) is a two doublet extension of the Higgs-Brout-Englert sector of the Standard Model with a Z2 symmetry in order to prevent FCNC. If the Z2 symmetry is not spontaneously broken, the lightest neutral extra scalar is a dark matter candidate. We briefly review the phenomenology of the model, emphasizing its relevance for the issue of Electroweak Symmetry Breaking (EWSB) and the prospects for detection of dark matter

  7. Gait Event Detection in Real-World Environment for Long-Term Applications: Incorporating Domain Knowledge Into Time-Frequency Analysis.

    Science.gov (United States)

    Khandelwal, Siddhartha; Wickstrom, Nicholas

    2016-12-01

    Detecting gait events is the key to many gait analysis applications that would benefit from continuous monitoring or long-term analysis. Most gait event detection algorithms using wearable sensors that offer a potential for use in daily living have been developed from data collected in controlled indoor experiments. However, for real-word applications, it is essential that the analysis is carried out in humans' natural environment; that involves different gait speeds, changing walking terrains, varying surface inclinations and regular turns among other factors. Existing domain knowledge in the form of principles or underlying fundamental gait relationships can be utilized to drive and support the data analysis in order to develop robust algorithms that can tackle real-world challenges in gait analysis. This paper presents a novel approach that exhibits how domain knowledge about human gait can be incorporated into time-frequency analysis to detect gait events from long-term accelerometer signals. The accuracy and robustness of the proposed algorithm are validated by experiments done in indoor and outdoor environments with approximately 93 600 gait events in total. The proposed algorithm exhibits consistently high performance scores across all datasets in both, indoor and outdoor environments.

  8. Vibrotactile Detection, Identification and Directional Perception of signal-Processed Sounds from Environmental Events: A Pilot Field Evaluation in Five Cases

    Directory of Open Access Journals (Sweden)

    Parivash Ranjbar

    2008-09-01

    Full Text Available Objectives: Conducting field tests of a vibrotactile aid for deaf/deafblind persons for detection, identification and directional perception of environmental sounds. Methods: Five deaf (3F/2M, 22–36 years individuals tested the aid separately in a home environment (kitchen and in a traffic environment. Their eyes were blindfolded and they wore a headband and holding a vibrator for sound identification. In the headband, three microphones were mounted and two vibrators for signalling direction of the sound source. The sounds originated from events typical for the home environment and traffic. The subjects were inexperienced (events unknown and experienced (events known. They identified the events in a home and traffic environment, but perceived sound source direction only in traffic. Results: The detection scores were higher than 98% both in the home and in the traffic environment. In the home environment, identification scores varied between 25%-58% when the subjects were inexperienced and between 33%-83% when they were experienced. In traffic, identification scores varied between 20%-40% when the subjects were inexperienced and between 22%-56% when they were experienced. The directional perception scores varied between 30%-60% when inexperienced and between 61%-83% when experienced. Discussion: The vibratory aid consistently improved all participants’ detection, identification and directional perception ability.

  9. Application of process monitoring to anomaly detection in nuclear material processing systems via system-centric event interpretation of data from multiple sensors of varying reliability

    International Nuclear Information System (INIS)

    Garcia, Humberto E.; Simpson, Michael F.; Lin, Wen-Chiao; Carlson, Reed B.; Yoo, Tae-Sic

    2017-01-01

    Highlights: • Process monitoring can strengthen nuclear safeguards and material accountancy. • Assessment is conducted at a system-centric level to improve safeguards effectiveness. • Anomaly detection is improved by integrating process and operation relationships. • Decision making is benefited from using sensor and event sequence information. • Formal framework enables optimization of sensor and data processing resources. - Abstract: In this paper, we apply an advanced safeguards approach and associated methods for process monitoring to a hypothetical nuclear material processing system. The assessment regarding the state of the processing facility is conducted at a system-centric level formulated in a hybrid framework. This utilizes architecture for integrating both time- and event-driven data and analysis for decision making. While the time-driven layers of the proposed architecture encompass more traditional process monitoring methods based on time series data and analysis, the event-driven layers encompass operation monitoring methods based on discrete event data and analysis. By integrating process- and operation-related information and methodologies within a unified framework, the task of anomaly detection is greatly improved. This is because decision-making can benefit from not only known time-series relationships among measured signals but also from known event sequence relationships among generated events. This available knowledge at both time series and discrete event layers can then be effectively used to synthesize observation solutions that optimally balance sensor and data processing requirements. The application of the proposed approach is then implemented on an illustrative monitored system based on pyroprocessing and results are discussed.

  10. Pulse oximetry recorded from the Phone Oximeter for detection of obstructive sleep apnea events with and without oxygen desaturation in children.

    Science.gov (United States)

    Garde, Ainara; Dehkordi, Parastoo; Wensley, David; Ansermino, J Mark; Dumont, Guy A

    2015-01-01

    Obstructive sleep apnea (OSA) disrupts normal ventilation during sleep and can lead to serious health problems in children if left untreated. Polysomnography, the gold standard for OSA diagnosis, is resource intensive and requires a specialized laboratory. Thus, we proposed to use the Phone Oximeter™, a portable device integrating pulse oximetry with a smartphone, to detect OSA events. As a proportion of OSA events occur without oxygen desaturation (defined as SpO2 decreases ≥ 3%), we suggest combining SpO2 and pulse rate variability (PRV) analysis to identify all OSA events and provide a more detailed sleep analysis. We recruited 160 children and recorded pulse oximetry consisting of SpO2 and plethysmography (PPG) using the Phone Oximeter™, alongside standard polysomnography. A sleep technician visually scored all OSA events with and without oxygen desaturation from polysomnography. We divided pulse oximetry signals into 1-min signal segments and extracted several features from SpO2 and PPG analysis in the time and frequency domain. Segments with OSA, especially the ones with oxygen desaturation, presented greater SpO2 variability and modulation reflected in the spectral domain than segments without OSA. Segments with OSA also showed higher heart rate and sympathetic activity through the PRV analysis relative to segments without OSA. PRV analysis was more sensitive than SpO2 analysis for identification of OSA events without oxygen desaturation. Combining SpO2 and PRV analysis enhanced OSA event detection through a multiple logistic regression model. The area under the ROC curve increased from 81% to 87%. Thus, the Phone Oximeter™ might be useful to monitor sleep and identify OSA events with and without oxygen desaturation at home.

  11. Event-specific qualitative and quantitative PCR detection of the GMO carnation (Dianthus caryophyllus) variety Moonlite based upon the 5'-transgene integration sequence.

    Science.gov (United States)

    Li, P; Jia, J W; Jiang, L X; Zhu, H; Bai, L; Wang, J B; Tang, X M; Pan, A H

    2012-04-27

    To ensure the implementation of genetically modified organism (GMO)-labeling regulations, an event-specific detection method was developed based on the junction sequence of an exogenous integrant in the transgenic carnation variety Moonlite. The 5'-transgene integration sequence was isolated by thermal asymmetric interlaced PCR. Based upon the 5'-transgene integration sequence, the event-specific primers and TaqMan probe were designed to amplify the fragments, which spanned the exogenous DNA and carnation genomic DNA. Qualitative and quantitative PCR assays were developed employing the designed primers and probe. The detection limit of the qualitative PCR assay was 0.05% for Moonlite in 100 ng total carnation genomic DNA, corresponding to about 79 copies of the carnation haploid genome; the limit of detection and quantification of the quantitative PCR assay were estimated to be 38 and 190 copies of haploid carnation genomic DNA, respectively. Carnation samples with different contents of genetically modified components were quantified and the bias between the observed and true values of three samples were lower than the acceptance criterion (GMO detection method. These results indicated that these event-specific methods would be useful for the identification and quantification of the GMO carnation Moonlite.

  12. The association of colonoscopy quality indicators with the detection of screen-relevant lesions, adverse events, and postcolonoscopy cancers in an asymptomatic Canadian colorectal cancer screening population.

    Science.gov (United States)

    Hilsden, Robert J; Dube, Catherine; Heitman, Steven J; Bridges, Ronald; McGregor, S Elizabeth; Rostom, Alaa

    2015-11-01

    Although several quality indicators of colonoscopy have been defined, quality assurance activities should be directed at the measurement of quality indicators that are predictive of key screening colonoscopy outcomes. The goal of this study was to examine the association among established quality indicators and the detection of screen-relevant lesions (SRLs), adverse events, and postcolonoscopy cancers. Historical cohort study. Canadian colorectal cancer screening center. A total of 18,456 asymptomatic men and women ages 40 to 74, at either average risk or increased risk for colorectal cancer because of a family history, who underwent a screening colonoscopy from 2008 to 2010. Using univariate and multivariate analyses, we explored the association among procedural quality indicators and 3 colonoscopy outcomes: detection of SRLs, adverse events, and postcolonoscopy cancers. The crude rates of SRLs, adverse events, and postcolonoscopy cancers were 240, 6.44, and .54 per 1000 colonoscopies, respectively. Several indicators, including endoscopist withdrawal time (OR, 1.3; 95% CI, 1.2-1.4) and cecal intubation rate (OR, 13.9; 95% CI, 1.9-96.9), were associated with the detection of SRLs. No quality indicator was associated with the risk of adverse events. Endoscopist average withdrawal time over 6 minutes (OR, .12; 95% CI, .002-.85) and SRL detection rate over 20% (OR, .17; 95% CI, .03-.74) were associated with a reduced risk of postcolonoscopy cancers. Single-center study. Quality assurance programs should prioritize the measurement of endoscopist average withdrawal time and adenoma (SRL) detection rate. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  13. Reconstruction efficiency and precision for the events detected by the BIS-2 installation using the Perun pattern recognition program

    International Nuclear Information System (INIS)

    Burilkov, D.T.; Genchev, V.I.; Markov, P.K.; Likhachev, M.F.; Takhtamyshev, G.G.; Todorov, P.T.; Trayanov, P.K.

    1982-01-01

    Results of studying the efficiency and accuracy of the track and event reconstruction with the Perun pattern recognition program used in the experiments carried out at the BIS-2 installation are presented. The Monte Carlo method is used for simulating the processes of neutron interactions with matter. The con-- clusion is made that the Perun program correctly, with good accuracy and high efficiency reconstructs complex multiparticle events [ru

  14. Solar neutrino detection in a large volume double-phase liquid argon experiment

    Energy Technology Data Exchange (ETDEWEB)

    Franco, D.; Agnes, P. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, Paris 75205 (France); Giganti, C.; Agostino, L.; De Cecco, S., E-mail: dfranco@in2p3.fr, E-mail: cgiganti@lpnhe.in2p3.fr, E-mail: pagnes@in2p3.fr, E-mail: lagostin@lpnhe.in2p3.fr, E-mail: sandro.dececco@lpnhe.in2p3.fr [LPNHE Paris, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris 75252 (France); and others

    2016-08-01

    Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne-yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the ''neutrino floor'' (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ∼15% precision, and significantly improve the precision of the {sup 7}Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  15. Direct dark matter detection with the DarkSide-50 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pagani, Luca [Univ. of Genoa (Italy)

    2017-01-01

    The existence of dark matter is known because of its gravitational effects, and although its nature remains undisclosed, there is a growing indication that the galactic halo could be permeated by weakly interacting massive particles (WIMPs) with mass of the order of $100$\\,GeV/c$^2$ and coupling with ordinary matter at or below the weak scale. In this context, DarkSide-50 aims to direct observe WIMP-nucleon collisions in a liquid argon dual phase time-projection chamber located deep underground at Gran Sasso National Laboratory, in Italy. In this work a re-analysis of the data that led to the best limit on WIMP-nucleon cross section with an argon target is done. As starting point of the new approach, the energy reconstruction of events is considered: a new energy variable is developed where anti-correlation between ionization and scintillation produced by an interaction is taken into account. As first result, a better energy resolution is achieved. In this new energy framewor k, access is granted to micro-physics parameters fundamental to argon scintillation such as the recombination and quenching as a function of the energy. The improved knowledge of recombination and quenching allows to develop a new model for distinguish between events possibly due to WIMPs and backgrounds. In light of the new model, the final result of this work is a more stringent limit on spin independent WIMP-nucleon cross section with an argon target. This work was supervised by Marco Pallavicini and was completed in collaboration with members of the DarkSide collaboration.

  16. Detection of zero anisotropy at 5.2 AU during the November 1998 solar particle event: Ulysses Anisotropy Telescopes observations

    Directory of Open Access Journals (Sweden)

    S. Dalla

    Full Text Available For the first time during the mission, the Anisotropy Telescopes instrument on board the Ulysses spacecraft measured constant zero anisotropy of protons in the 1.3-2.2 MeV energy range, for a period lasting more than three days. This measurement was made during the energetic particle event taking place at Ulysses between 25 November and 15 December 1998, an event characterised by constant high proton fluxes within a region delimited by two interplanetary forward shocks, at a distance of 5.2 AU from the Sun and heliographic latitude of 17°S. We present the ATs results for this event and discuss their possible interpretation and their relevance to the issue of intercalibration of the two telescopes.

    Key words: Interplanetary physics (energetic particles - Solar physics, astrophysics and astronomy (energetic particles - Space plasma physics (instruments and techniques

  17. Dark Kinetic Heating of Neutron Stars and an Infrared Window on WIMPs, SIMPs, and Pure Higgsinos.

    Science.gov (United States)

    Baryakhtar, Masha; Bramante, Joseph; Li, Shirley Weishi; Linden, Tim; Raj, Nirmal

    2017-09-29

    We identify a largely model-independent signature of dark matter (DM) interactions with nucleons and electrons. DM in the local galactic halo, gravitationally accelerated to over half the speed of light, scatters against and deposits kinetic energy into neutron stars, heating them to infrared blackbody temperatures. The resulting radiation could potentially be detected by the James Webb Space Telescope, the Thirty Meter Telescope, or the European Extremely Large Telescope. This mechanism also produces optical emission from neutron stars in the galactic bulge, and x-ray emission near the galactic center because dark matter is denser in these regions. For GeV-PeV mass dark matter, dark kinetic heating would initially unmask any spin-independent or spin-dependent dark matter-nucleon cross sections exceeding 2×10^{-45}  cm^{2}, with improved sensitivity after more telescope exposure. For lighter-than-GeV dark matter, cross-section sensitivity scales inversely with dark matter mass because of Pauli blocking; for heavier-than-PeV dark matter, it scales linearly with mass as a result of needing multiple scatters for capture. Future observations of dark sector-warmed neutron stars could determine whether dark matter annihilates in or only kinetically heats neutron stars. Because inelastic interstate transitions of up to a few GeV would occur in relativistic scattering against nucleons, elusive inelastic dark matter like pure Higgsinos can also be discovered.

  18. Impact of Sommerfeld enhancement on helium reionization via WIMP dark matter

    Science.gov (United States)

    Bandyopadhyay, Bidisha; Schleicher, Dominik R. G.

    2018-03-01

    Dark matter annihilation can have a strong impact on many astrophysical processes in the Universe. In the case of Sommerfeld-enhanced annihilation cross sections, the annihilation rates are enhanced at late times, thus enhancing the potential annihilation signatures. We here calculate the Sommerfeld-enhanced annihilation signatures during the epoch of helium reionization, the epoch where helium becomes fully ionized due to energetic photons. When considering the upper limits on the energy injection from the CMB, we find that the resulting abundance of He++ becomes independent of the dark matter particle mass. The resulting enhancement compared to a standard scenario is thus 1-2 orders of magnitude higher. For realistic scenarios compatible with CMB constraints, there is no significant shift in the epoch of helium reionization, which is completed between redshifts 3 and 4. While it is thus difficult to disentangle dark matter annihilation from astrophysical contributions (active galactic nuclei), a potential detection of dark matter particles and its interactions using the Large Hadron Collider (LHC) would allow one to quantify the dark matter contribution.

  19. Direct detection of non-baryonic dark matter

    International Nuclear Information System (INIS)

    Nollez, G.

    2003-01-01

    Baryonic matter, which constitutes stars and galaxies, amounts to a few percents of the mass of the universe in agreement with the theory of the big-bang nucleosynthesis. Most of the matter in the universe (approximately 85%) is then non-baryonic and dark. One of the most favoured hypothesis is that this non-baryonic dark matter is constituted by a new type, still undiscovered, of elementary weakly interacting massive particles (wimps). These hypothetical particles would appear as thermal relics from the big-bang era during which they were created. A rich spectrum of new elementary particles is predicted by supersymmetry, the lightest of which is the neutralino. If the dark matter halo of our Milky-way is made of neutralinos, their detection in terrestrial detectors should be possible. Neutralinos are coupled to matter through the electroweak interaction, this implies that the detection rate is extraordinary low. About 10 experiments in the world are dedicated to the search after wimps. A first group of experiments (HDMS, IGEX, DAMA and Zeplin) use 'classical' detectors of nuclear physics, germanium semiconductor diodes or NaI scintillators. A second group (CDMS, Edelweiss) gathers cryogenic phonon ionisation experiments and a third group (CRESST, Rosebud) is based on cryogenic phonon-light experiments. Till now no wimps has been clearly detected, the direct detection story is obviously not concluded, most of the future experiments aim to reach a sensitivity of 10 -44 cm 2 . (A.C.)

  20. Compatibility of a dark matter discovery at XENONnT or LZ with the WIMP thermal production mechanism

    Science.gov (United States)

    Catena, Riccardo; Conrad, Jan; Krauss, Martin B.

    2018-05-01

    The discovery of dark matter (DM) at XENONnT or LZ would place constraints on DM particle mass and coupling constants. It is interesting to ask when these constraints can be compatible with the DM thermal production mechanism. We address this question within the most general set of renormalizable models that preserve Lorentz and gauge symmetry, and that extend the standard model by one DM candidate of mass mDM and one particle of mass Mmed mediating DM-quark interactions. Our analysis divides into two parts. First, we postulate that XENONnT/LZ has detected μS˜O (100 ) signal events, and use this input to calculate the DM relic density, ΩDMh2. Then, we identify the regions in the Mmed-ΩDMh2 plane which are compatible with the observed signal and with current CMB data. We find that for most of the models considered here, O (100 ) signal events at XENONnT/LZ and the DM thermal production are only compatible for resonant DM annihilations, i.e. for Mmed≃2 mDM. In this case, XENONnT/LZ would be able to simultaneously measure mDM and Mmed. We also discuss the dependence of our results on mDM, μS and the DM spin, and provide analytic expressions for annihilation cross sections and mediator decay widths for all models considered in this study.

  1. Auto-adaptive averaging: Detecting artifacts in event-related potential data using a fully automated procedure

    NARCIS (Netherlands)

    Talsma, D.

    2008-01-01

    The auto-adaptive averaging procedure proposed here classifies artifacts in event-related potential data by optimizing the signal-to-noise ratio. This method rank orders single trials according to the impact of each trial on the ERP average. Then, the minimum residual background noise level in the

  2. Auto-adaptive averaging: Detecting artifacts in event-related potential data using a fully automated procedure.

    NARCIS (Netherlands)

    Talsma, D.

    2008-01-01

    The auto-adaptive averaging procedure proposed here classifies artifacts in event-related potential data by optimizing the signal-to-noise ratio. This method rank orders single trials according to the impact of each trial on the ERP average. Then, the minimum residual background noise level in the

  3. Phenotyping for patient safety: algorithm development for electronic health record based automated adverse event and medical error detection in neonatal intensive care.

    Science.gov (United States)

    Li, Qi; Melton, Kristin; Lingren, Todd; Kirkendall, Eric S; Hall, Eric; Zhai, Haijun; Ni, Yizhao; Kaiser, Megan; Stoutenborough, Laura; Solti, Imre

    2014-01-01

    Although electronic health records (EHRs) have the potential to provide a foundation for quality and safety algorithms, few studies have measured their impact on automated adverse event (AE) and medical error (ME) detection within the neonatal intensive care unit (NICU) environment. This paper presents two phenotyping AE and ME detection algorithms (ie, IV infiltrations, narcotic medication oversedation and dosing errors) and describes manual annotation of airway management and medication/fluid AEs from NICU EHRs. From 753 NICU patient EHRs from 2011, we developed two automatic AE/ME detection algorithms, and manually annotated 11 classes of AEs in 3263 clinical notes. Performance of the automatic AE/ME detection algorithms was compared to trigger tool and voluntary incident reporting results. AEs in clinical notes were double annotated and consensus achieved under neonatologist supervision. Sensitivity, positive predictive value (PPV), and specificity are reported. Twelve severe IV infiltrates were detected. The algorithm identified one more infiltrate than the trigger tool and eight more than incident reporting. One narcotic oversedation was detected demonstrating 100% agreement with the trigger tool. Additionally, 17 narcotic medication MEs were detected, an increase of 16 cases over voluntary incident reporting. Automated AE/ME detection algorithms provide higher sensitivity and PPV than currently used trigger tools or voluntary incident-reporting systems, including identification of potential dosing and frequency errors that current methods are unequipped to detect. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Lessons derived from two high-frequency sea level events in the Atlantic: implications for coastal risk analysis and tsunami detection

    Directory of Open Access Journals (Sweden)

    Begoña Pérez-Gómez

    2016-11-01

    Full Text Available The upgrade and enhancement of sea level networks worldwide for integration in sea level hazard warning systems have significantly increased the possibilities for measuring and analyzing high frequency sea level oscillations, with typical periods ranging from a few minutes to a few hours. Many tide gauges now afford 1 min or more frequent sampling and have shown such events to be a common occurrence. Their origins and spatial distribution are diverse and must be well understood in order to correctly design and interpret, for example, the automatic detection algorithms used by tsunami warning centers. Two events recorded recently in European Atlantic waters are analyzed here: possible wave-induced seiches that occurred along the North coast of Spain during the storms of January and February of 2014, and oscillations detected after an earthquake in the mid-Atlantic the 13th of February of 2015. The former caused significant flooding in towns and villages and a huge increase in wave-induced coastal damage that was reported in the media for weeks. The second was a smaller signal present in several tide gauges along the Atlantic coast that, that coincided with the occurrence of this earthquake, leading to a debate on the potential detection of a very small tsunami and how it might yield significant information for tsunami wave modelers and for the development of tsunami detection software. These kinds of events inform us about the limitations of automatic algorithms for tsunami warning and help to improve the information provided to tsunami warning centers, whilst also emphasizing the importance of other forcings in generating extreme sea levels and their associated potential for causing damage to infrastructure.

  5. Novel ST-MUSIC-based spectral analysis for detection of ULF geomagnetic signals anomalies associated with seismic events in Mexico

    Directory of Open Access Journals (Sweden)

    Omar Chavez

    2016-05-01

    Full Text Available Recently, the analysis of ultra-low-frequency (ULF geomagnetic signals in order to detect seismic anomalies has been reported in several works. Yet, they, although having promising results, present problems for their detection since these anomalies are generally too much weak and embedded in high noise levels. In this work, a short-time multiple signal classification (ST-MUSIC, which is a technique with high-frequency resolution and noise immunity, is proposed for the detection of seismic anomalies in the ULF geomagnetic signals. Besides, the energy (E of geomagnetic signals processed by ST-MUSIC is also presented as a complementary parameter to measure the fluctuations between seismic activity and seismic calm period. The usefulness and effectiveness of the proposal are demonstrated through the analysis of a synthetic signal and five real signals with earthquakes. The analysed ULF geomagnetic signals have been obtained using a tri-axial fluxgate magnetometer at the Juriquilla station, which is localized in Queretaro, Mexico (geographic coordinates: longitude 100.45° E and latitude 20.70° N. The results obtained show the detection of seismic perturbations before, during, and after the main shock, making the proposal a suitable tool for detecting seismic precursors.

  6. Detection and Modeling of a Meteotsunami in Lake Erie During a High Wind Event on May 27, 2012

    Science.gov (United States)

    Anderson, E. J.; Schwab, D. J.; Lombardy, K. A.; LaPlante, R. E.

    2012-12-01

    On May 27, 2012, a mesoscale convective system moved southeast across the central basin of Lake Erie (the shallowest of the Grea