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Sample records for single seismic event

  1. A single geophone to locate seismic events on Mars

    Science.gov (United States)

    Roques, Aurélien; Berenguer, Jean-Luc; Bozdag, Ebru

    2016-04-01

    Knowing the structure of Mars is a key point in understanding the formation of Earth-like planets as plate tectonics and erosion have erased the original suface of the Earth formation. Installing a seismometer on Mars surface makes it possible to identify its structure. An important step in the identification of the structure of a planet is the epicenter's location of a seismic source, typically a meteoric impact or an earthquake. On Earth, the classical way of locating epicenters is triangulation, which requires at least 3 stations. The Mars InSight Project plans to set a single station with 3 components. We propose a software to locate seismic sources on Mars thanks to the 3-components simulated data of an earthquake given by Geoazur (Nice Sophia-Antipolis University, CNRS) researchers. Instrumental response of a sensor is crucial for data interpretation. We study the oscillations of geophone in several situations so as to awaken students to the meaning of damping in second order modeling. In physics, car shock absorbers are often used to illustrate the principle of damping but rarely in practical experiments. We propose the use of a simple seismometer (a string with a mass and a damper) that allows changing several parameters (inductive damping, temperature and pressure) so as to see the effects of these parameters on the impulse response and, in particular, on the damping coefficient. In a second step, we illustrate the effect of damping on a seismogram with the difficulty of identifying and interpreting the different phase arrival times with low damping.

  2. Aftershock Sequences and Seismic-Like Organization of Acoustic Events Produced by a Single Propagating Crack

    Science.gov (United States)

    Alizee, D.; Bonamy, D.

    2017-12-01

    In inhomogeneous brittle solids like rocks, concrete or ceramics, one usually distinguish nominally brittle fracture, driven by the propagation of a single crack from quasibrittle one, resulting from the accumulation of many microcracks. The latter goes along with intermittent sharp noise, as e.g. revealed by the acoustic emission observed in lab scale compressive fracture experiments or at geophysical scale in the seismic activity. In both cases, statistical analyses have revealed a complex time-energy organization into aftershock sequences obeying a range of robust empirical scaling laws (the Omori-Utsu, productivity and Bath's law) that help carry out seismic hazard analysis and damage mitigation. These laws are usually conjectured to emerge from the collective dynamics of microcrack nucleation. In the experiments presented at AGU, we will show that such a statistical organization is not specific to the quasi-brittle multicracking situations, but also rules the acoustic events produced by a single crack slowly driven in an artificial rock made of sintered polymer beads. This simpler situation has advantageous properties (statistical stationarity in particular) permitting us to uncover the origins of these seismic laws: Both productivity law and Bath's law result from the scale free statistics for event energy and Omori-Utsu law results from the scale-free statistics of inter-event time. This yields predictions on how the associated parameters are related, which were analytically derived. Surprisingly, the so-obtained relations are also compatible with observations on lab scale compressive fracture experiments, suggesting that, in these complex multicracking situations also, the organization into aftershock sequences and associated seismic laws are also ruled by the propagation of individual microcrack fronts, and not by the collective, stress-mediated, microcrack nucleation. Conversely, the relations are not fulfilled in seismology signals, suggesting that

  3. Monitoring of seismic events from a specific source region using a single regional array: A case study

    Science.gov (United States)

    Gibbons, S. J.; Kværna, T.; Ringdal, F.

    2005-07-01

    In the monitoring of earthquakes and nuclear explosions using a sparse worldwide network of seismic stations, it is frequently necessary to make reliable location estimates using a single seismic array. It is also desirable to screen out routine industrial explosions automatically in order that analyst resources are not wasted upon detections which can, with a high level of confidence, be associated with such a source. The Kovdor mine on the Kola Peninsula of NW Russia is the site of frequent industrial blasts which are well recorded by the ARCES regional seismic array at a distance of approximately 300 km. We describe here an automatic procedure for identifying signals which are likely to result from blasts at the Kovdor mine and, wherever possible, for obtaining single array locations for such events. Carefully calibrated processing parameters were chosen using measurements from confirmed events at the mine over a one-year period for which the operators supplied Ground Truth information. Phase arrival times are estimated using an autoregressive method and slowness and azimuth are estimated using broadband f{-} k analysis in fixed frequency bands and time-windows fixed relative to the initial P-onset time. We demonstrate the improvement to slowness estimates resulting from the use of fixed frequency bands. Events can be located using a single array if, in addition to the P-phase, at least one secondary phase is found with both an acceptable slowness estimate and valid onset-time estimate. We evaluate the on-line system over a twelve month period; every event known to have occured at the mine is detected by the process and 32 out of 53 confirmed events were located automatically. The remaining events were classified as “very likely” Kovdor events and were subsequently located by an analyst. The false alarm rate is low; only 84 very likely Kovdor events were identified during the whole of 2003 and none of these were subsequently located at a large distance from

  4. The ISC Seismic Event Bibliography

    Science.gov (United States)

    Di Giacomo, Domenico; Storchak, Dmitry

    2015-04-01

    The International Seismological Centre (ISC) is a not-for-profit organization operating in the UK for the last 50 years and producing the ISC Bulletin - the definitive worldwide summary of seismic events, both natural and anthropogenic - starting from the beginning of 20th century. Often researchers need to gather information related to specific seismic events for various reasons. To facilitate such task, in 2012 we set up a new database linking earthquakes and other seismic events in the ISC Bulletin to bibliographic records of scientific articles (mostly peer-reviewed journals) that describe those events. Such association allows users of the ISC Event Bibliography (www.isc.ac.uk/event_bibliography/index.php) to run searches for publications via a map-based web interface and, optionally, selecting scientific publications related to either specific events or events in the area of interest. Some of the greatest earthquakes were described in several hundreds of articles published over a period of few years. The journals included in our database are not limited to seismology but bring together a variety of fields in geosciences (e.g., engineering seismology, geodesy and remote sensing, tectonophysics, monitoring research, tsunami, geology, geochemistry, hydrogeology, atmospheric sciences, etc.) making this service useful in multidisciplinary studies. Usually papers dealing with large data set are not included (e.g., papers describing a seismic catalogue). Currently the ISC Event Bibliography includes over 17,000 individual publications from about 500 titles related to over 14,000 events that occurred in last 100+ years. The bibliographic records in the Event Bibliography start in the 1950s, and it is updated as new publications become available.

  5. Detection and identification of sources of very distant seismic events in Western United States using single array seismograms

    International Nuclear Information System (INIS)

    Roy, Falguni; Basu, T.K.; Arora, S.K.

    1993-01-01

    In search of a new source discriminant based on the characteristics of PP signal, a study has been made by special further processing of Gauribidanur array (GBA) seismograms of underground explosions at Nevada Test Site (NTS) in Southern Nevada and of tectonic earthquakes in five provinces in the Western United States (US), both class of events being situated in the far teleseismic distance range (120deg<Δ<131deg) where GBA lies in the core shadow zone with respect to the source region. This study aims to evolve aids of detection and identification of such distant and small seismic events using GBA data alone. Preliminary analysis of the processed short period signals from seventeen Western US earthquakes and twelve NTS explosions shows that, for a given body wave magnitude (Mb), the relative high frequency spectral content of core-refracted P waves as well as the ratio of PP to P energy for the earthquakes are in general more than those of the explosions. The PP discriminant and the third moment of frequency (TMF) along with the Mb:Ms criterion, wherever possible, seem to be promising as an effective means of identifying Western US events. It is demonstrated that by applying in tandem the above three identifiers to the set of twenty-nine known events in the magnitude range 4.8≤Mb≤5.9, all the events of Mb 4.9 and above could be identified unambiguously. (author). 30 refs., 16 figs., 1 tab

  6. 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

  7. 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.

  8. Probabilistic safety assessment for seismic events

    International Nuclear Information System (INIS)

    1993-10-01

    This Technical Document on Probabilistic Safety Assessment for Seismic Events is mainly associated with the Safety Practice on Treatment of External Hazards in PSA and discusses in detail one specific external hazard, i.e. earthquakes

  9. Seismic Event Relocation in Northeastern Russia

    Science.gov (United States)

    Romero-Yeske, M. D.; Steck, L.; Begnaud, M. L.; Mackey, K. G.; Fujita, K.; Stead, R.

    2009-12-01

    Northeastern Russia covers an area roughly equivalent to the United States, with seven seismic networks operating independently. Together, Michigan State University and Los Alamos National Laboratory researchers have merged catalogs from the Yakutsk, Magadan, Sakhalin, Kamchatka, and Irkutsk networks along with global bulletins and special studies to produce a unified research database for the region. We have developed regional phase travel time correction surfaces for P, Pn, Pg, S, and Sg/Lg using GT25 or better events, and are beginning to test relocation capabilities of less-well-constrained events with these kriged correction surfaces. Improvements in location will be judged on the basis of increased linearity and clustering of events across the study region, spanning a box from 40-75 degrees latitude and 80-190 degrees longitude. Relocation results for different combinations of phases will be presented.

  10. Single-block rockfall dynamics inferred from seismic signal analysis

    Directory of Open Access Journals (Sweden)

    C. Hibert

    2017-05-01

    Full Text Available Seismic monitoring of mass movements can significantly help to mitigate the associated hazards; however, the link between event dynamics and the seismic signals generated is not completely understood. To better understand these relationships, we conducted controlled releases of single blocks within a soft-rock (black marls gully of the Rioux-Bourdoux torrent (French Alps. A total of 28 blocks, with masses ranging from 76 to 472 kg, were used for the experiment. An instrumentation combining video cameras and seismometers was deployed along the travelled path. The video cameras allow reconstructing the trajectories of the blocks and estimating their velocities at the time of the different impacts with the slope. These data are compared to the recorded seismic signals. As the distance between the falling block and the seismic sensors at the time of each impact is known, we were able to determine the associated seismic signal amplitude corrected for propagation and attenuation effects. We compared the velocity, the potential energy lost, the kinetic energy and the momentum of the block at each impact to the true amplitude and the radiated seismic energy. Our results suggest that the amplitude of the seismic signal is correlated to the momentum of the block at the impact. We also found relationships between the potential energy lost, the kinetic energy and the seismic energy radiated by the impacts. Thanks to these relationships, we were able to retrieve the mass and the velocity before impact of each block directly from the seismic signal. Despite high uncertainties, the values found are close to the true values of the masses and the velocities of the blocks. These relationships allow for gaining a better understanding of the physical processes that control the source of high-frequency seismic signals generated by rockfalls.

  11. Intelligent post processing of seismic events

    Directory of Open Access Journals (Sweden)

    F. Ringdal

    1994-06-01

    Full Text Available The Intelligent Monitoring Systern (IMS currently provides for joint processing of data from six arrays located in Northern and Central Europe. From experience with analyst review of events automatically defined by the IMS, we bave realized that the quality of the automatic event locations can be significantly improved if the event intervals are reprocessed with signal processing pararneters tuned to phases from events in the given region. The tuned processing parameters are obtained from off line analysis of events located in the region of interest. The primary goal of such intelligent post processing is to provide event definitions of a quality that minimizes the need for subsequent manual analysis. The first step in this post processing is to subdivide the arca to be monitored in order to identify sites of interest. Clearly, calibration will be the easiest and potential savings in manpower are the largest for areas of high, recurring seismicity. We bave identified 8 mining sites in Fennoscandia/NW Russia and noted that 65.6% of the events of ML > 2.0 in this region can be associated with one of these sites. This result is based on 1 year and a half of data. The second step is to refine the phase arrival and azimuth estimates using frequency filters and processing parameters that are tuned to the initial event location provided by the IMS. In this study, we have analyzed a set of 52 mining explosions from the Khibiny Massif mining area in the Kola peninsula of Russia. Very accurate locations of these events bave been provided by the seismologists from the Kola Regional Seismology Centre. Using an autoregressive likelihood technique we have been able to estimate onset times to an accuracy (standard deviation of about 0.05 s for P phases and 0.15 0.20 s for S phases. Using fixed frequency bands, azimuth can be estimated to an accuracy (one standard deviation of 0.9 degrees for the ARCESS array and 3 4 degrees for the small array recently

  12. A Bayesian Method to Apply the Results of Multiple-Event Seismic Location to a Subsequent Event

    Science.gov (United States)

    Johannesson, G.; Myers, S. C.

    2014-12-01

    BayesLoc is a Bayesian multiple-event seismic locator that uses a Markov chain Monte Carlo (MCMC) algorithm to sample possible seismic hypocenters, travel-time corrections, and the precision of observed arrival data (absolute picks and differential times based on cross-correlated waveforms). By simultaneously locating multiple seismic events, regional biases in the assumed travel-time model (e.g., ak135) can be estimated and corrected for, and data from different seismic stations and phases can be weighted to reflect their accuracy/precision for an event cluster. As such, multiple-event locators generally yield more accurate locations than single-event locators, which lack the data to resolve the underlying travel-time model and adaptively "weight" the arrival data differently for each station and phase. On the other hand, single-event locators are computationally more attractive, making them more suitable for rapid (realtime) location of seismic activity. We present a novel approach to approximate the location accuracy of the BayesLoc multiple-event analysis at a computational cost that is comparable to BayesLoc single-event analysis. The proposed approach consists of two steps: a precomputed multiple-event training analysis and subsequent real-time, single-event location for new events. The precomputed training analsysis consists of carrying out a multiple-event BayesLoc run in a given target event cluster, yielding a posterior sample of travel-time corrections and weights. Given a new event in the vicinity of the training cluster, a BayesLoc single-event run is carried out which samples the travel-time corrections and weights from the multiple-event training run. Hence, it has all the benefits of the multiple-event run at the cost of a single-event run. We present the theoretical underpinnings of the new approach and we compare event location results for the full multiple-event, single-event, and the new approaches. This work was performed under the auspices of

  13. Moment magnitude determination of local seismic events recorded at selected Polish seismic stations

    Science.gov (United States)

    Wiejacz, Paweł; Wiszniowski, Jan

    2006-03-01

    The paper presents the method of local magnitude determination used at Polish seismic stations to report events originating in one of the four regions of induced seismicity in Poland or its immediate vicinity. The method is based on recalculation of the seismic moment into magnitude, whereas the seismic moment is obtained from spectral analysis. The method has been introduced at Polish seismic stations in the late 1990s but as of yet had not been described in full because magnitude discrepancies have been found between the results of the individual stations. The authors have performed statistics of these differences, provide their explanation and calculate station corrections for each station and each event source region. The limitations of the method are also discussed. The method is found to be a good and reliable method of local magnitude determination provided the limitations are observed and station correction applied.

  14. Link Between the Seismic Events and the Different Seismic Precursor Phenomena

    Directory of Open Access Journals (Sweden)

    Mirela GHEORGHITA

    2009-12-01

    Full Text Available This article presents an analysis of the earthquake prediction methods, highlighting mainly the VLF and LF electromagnetic waves seismic precursors’ monitoring method and the correlation among these in order to obtain a more precise result. It is well known the fact that there are lots of links between the seismic events occurrence and different phenomena that predict their occurrence, such as theelectromagnetic field, Earth movement, gaseous content of radon and hydrogen within the soil, or within the underground waters. This paper aims to demonstrate the close link between the seismic events and the electromagnetic wave propagation anomalies, which are recorded before the advent of an earthquake.

  15. Automatic Seismic-Event Classification with Convolutional Neural Networks.

    Science.gov (United States)

    Bueno Rodriguez, A.; Titos Luzón, M.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

    2017-12-01

    Active volcanoes exhibit a wide range of seismic signals, providing vast amounts of unlabelled volcano-seismic data that can be analyzed through the lens of artificial intelligence. However, obtaining high-quality labelled data is time-consuming and expensive. Deep neural networks can process data in their raw form, compute high-level features and provide a better representation of the input data distribution. These systems can be deployed to classify seismic data at scale, enhance current early-warning systems and build extensive seismic catalogs. In this research, we aim to classify spectrograms from seven different seismic events registered at "Volcán de Fuego" (Colima, Mexico), during four eruptive periods. Our approach is based on convolutional neural networks (CNNs), a sub-type of deep neural networks that can exploit grid structure from the data. Volcano-seismic signals can be mapped into a grid-like structure using the spectrogram: a representation of the temporal evolution in terms of time and frequency. Spectrograms were computed from the data using Hamming windows with 4 seconds length, 2.5 seconds overlapping and 128 points FFT resolution. Results are compared to deep neural networks, random forest and SVMs. Experiments show that CNNs can exploit temporal and frequency information, attaining a classification accuracy of 93%, similar to deep networks 91% but outperforming SVM and random forest. These results empirically show that CNNs are powerful models to classify a wide range of volcano-seismic signals, and achieve good generalization. Furthermore, volcano-seismic spectrograms contains useful discriminative information for the CNN, as higher layers of the network combine high-level features computed for each frequency band, helping to detect simultaneous events in time. Being at the intersection of deep learning and geophysics, this research enables future studies of how CNNs can be used in volcano monitoring to accurately determine the detection and

  16. Evaluation of Fourier integral. Spectral analysis of seismic events

    International Nuclear Information System (INIS)

    Chitaru, Cristian; Enescu, Dumitru

    2003-01-01

    Spectral analysis of seismic events represents a method for great earthquake prediction. The seismic signal is not a sinusoidal signal; for this, it is necessary to find a method for best approximation of real signal with a sinusoidal signal. The 'Quanterra' broadband station allows the data access in numerical and/or graphical forms. With the numerical form we can easily make a computer program (MSOFFICE-EXCEL) for spectral analysis. (authors)

  17. Impact of seismic events on containment and consequence analysis

    International Nuclear Information System (INIS)

    Lutz, R.J. Jr.; Holmes, B.G.; Vavrek, K.J.

    1985-01-01

    A level 3 probabilistic risk assessment study includes analysis of the plant response to initiating events, analysis of the containment response to degraded core events, fission product source term analysis and consequence analysis. The analysis of the plant response to initiating events must consider both events which occur within the plant systems which challenge the plant safety system (internal initiating events) and events which occur external to the plant systems (external initiating events). The Millstone Unit 3 Probabilistic Safety Study considered the containment and consequence analyses for the dominant event sequences defined in the plant analysis with separate treatment of internal initiating events and external initiating events. The results, as detailed herein, indicate that separate consideration of external initiating events, particularly seismic initiating events, have a significant impact on the containment and consequence analyses for both internal and external initiating events. By treating seismic events separately, more realistic models and assumptions could be used for the internal initiating events analysis as opposed to the bounding approach. The result is directly translated to the risk estimates, including uncertainty for both internal and external initiating events

  18. Landquake dynamics inferred from seismic source inversion: Greenland and Sichuan events of 2017

    Science.gov (United States)

    Chao, W. A.

    2017-12-01

    In June 2017 two catastrophic landquake events occurred in Greenland and Sichuan. The Greenland event leads to tsunami hazard in the small town of Nuugaarsiaq. A landquake in Sichuan hit the town, which resulted in over 100 death. Both two events generated the strong seismic signals recorded by the real-time global seismic network. I adopt an inversion algorithm to derive the landquake force time history (LFH) using the long-period waveforms, and the landslide volume ( 76 million m3) can be rapidly estimated, facilitating the tsunami-wave modeling for early warning purpose. Based on an integrated approach involving tsunami forward simulation and seismic waveform inversion, this study has significant implications to issuing actionable warnings before hazardous tsunami waves strike populated areas. Two single-forces (SFs) mechanism (two block model) yields the best explanation for Sichuan event, which demonstrates that secondary event (seismic inferred volume: 8.2 million m3) may be mobilized by collapse-mass hitting from initial rock avalanches ( 5.8 million m3), likely causing a catastrophic disaster. The later source with a force magnitude of 0.9967×1011 N occurred 70 seconds after first mass-movement occurrence. In contrast, first event has the smaller force magnitude of 0.8116×1011 N. In conclusion, seismically inferred physical parameters will substantially contribute to improving our understanding of landquake source mechanisms and mitigating similar hazards in other parts of the world.

  19. A methodology for the quantitative risk assessment of major accidents triggered by seismic events.

    Science.gov (United States)

    Antonioni, Giacomo; Spadoni, Gigliola; Cozzani, Valerio

    2007-08-17

    A procedure for the quantitative risk assessment of accidents triggered by seismic events in industrial facilities was developed. The starting point of the procedure was the use of available historical data to assess the expected frequencies and the severity of seismic events. Available equipment-dependant failure probability models (vulnerability or fragility curves) were used to assess the damage probability of equipment items due to a seismic event. An analytic procedure was subsequently developed to identify, evaluate the credibility and finally assess the expected consequences of all the possible scenarios that may follow the seismic events. The procedure was implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities. The developed methodology requires a limited amount of additional data with respect to those used in a conventional QRA, and yields with a limited effort a preliminary quantitative assessment of the contribution of the scenarios triggered by earthquakes to the individual and societal risk indexes. The application of the methodology to several case-studies evidenced that the scenarios initiated by seismic events may have a relevant influence on industrial risk, both raising the overall expected frequency of single scenarios and causing specific severe scenarios simultaneously involving several plant units.

  20. 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

  1. Crystal ball single event display

    International Nuclear Information System (INIS)

    Grosnick, D.; Gibson, A.; Allgower, C.; Alyea, J.; Argonne National Lab., IL

    1997-01-01

    The Single Event Display (SED) is a routine that is designed to provide information graphically about a triggered event within the Crystal Ball. The SED is written entirely in FORTRAN and uses the CERN-based HICZ graphing package. The primary display shows the amount of energy deposited in each of the NaI crystals on a Mercator-like projection of the crystals. Ten different shades and colors correspond to varying amounts of energy deposited within a crystal. Information about energy clusters is displayed on the crystal map by outlining in red the thirteen (or twelve) crystals contained within a cluster and assigning each cluster a number. Additional information about energy clusters is provided in a series of boxes containing useful data about the energy distribution among the crystals within the cluster. Other information shown on the event display include the event trigger type and data about π o 's and η's formed from pairs of clusters as found by the analyzer. A description of the major features is given, along with some information on how to install the SED into the analyzer

  2. Correlation Between Electromagnetic Signals and Seismic Events on Central Colombia Region to Establish Seismic Precursors Existence

    Science.gov (United States)

    Caneva, A.; Vargas Jiménez, C. A.; Solano Fino, J. M.

    2017-12-01

    It was already shown by several authors around the world some kinds of correlation between electric and magnetic signals and seismic events looking for precursors to the last ones emitted from the seismic source. This investigation tends to establish a correlation between electro-magnetic (EM) signals on the ground surface and seismic events on the Colombian lithospheric system. The events correlation was made with data from the Seismological Network of the Sabana de Bogotá (RSSB for its acronym in Spanish), a temporal seismological network on Chichimene (Acacías, Meta, Colombia) and the National Seismological Network of Colombia (RSNC, for its acronym in Spanish). The project involved the design, construction and preliminary tests for the necessary instruments added to the RSSB as multi-parameter stations with seismic broadband, electric polarizing and non-polarizing dipoles and Earth's magnetic field sensors. Correlations were made considering time, frequency and `natural time' domains with filtering and preprocessing algorithms. Among the main results are the almost complete lack of electric disturbances known as Seismic Electric Signals (SES) and very few of the magnetic kind. However, another kind of long period magnetic disturbances for some stations and events where found. More instruments have to be deployed in order to get a better understanding of these disturbances and develop a robust model.

  3. Single event upset test programs

    International Nuclear Information System (INIS)

    Russen, L.C.

    1984-11-01

    It has been shown that the heavy ions in cosmic rays can give rise to single event upsets in VLSI random access memory devices (RAMs). Details are given of the programs written to test 1K, 4K, 16K and 64K memories during their irradiation with heavy charged ions, in order to simulate the effects of cosmic rays in space. The test equipment, which is used to load the memory device to be tested with a known bit pattern, and subsequently interrogate it for upsets, or ''flips'', is fully described. (author)

  4. Seismic spectra of events at regional distances

    International Nuclear Information System (INIS)

    Springer, D.L.; Denny, M.D.

    1976-01-01

    About 40 underground nuclear explosions detonated at the Nevada Test Site (NTS) were chosen for analysis of their spectra and any relationships they might have to source parameters such as yield, depth of burial, etc. The sample covered a large yield range (less than 20 kt to greater than 1 Mt). Broadband (0.05 to 20 Hz) data recorded by the four-station seismic network operated by Lawrence Livermore Laboratory were analyzed in a search for unusual explosion signatures in their spectra. Long time windows (total wave train) as well as shorter windows (for instance, P/sub n/) were used as input to calculate the spectra. Much variation in the spectra of the long windows is typical although some gross features are similar, such as a dominant peak in the microseismic window. The variation is such that selection of corner frequencies is impractical and yield scaling could not be determined. Spectra for one NTS earthquake showed more energy in the short periods (less than 1 sec) as well as in the long periods (greater than 8 sec) compared to those for NTS explosions

  5. Prediction of magnitude of the largest potentially induced seismic event

    Czech Academy of Sciences Publication Activity Database

    Hallo, M.; Opršal, I.; Eisner, Leo; Ali, M.Y.

    2014-01-01

    Roč. 18, č. 3 (2014), s. 421-431 ISSN 1383-4649 R&D Projects: GA ČR GAP210/12/2451 Institutional support: RVO:67985891 Keywords : magnitude * seismic moment * b value * induced events Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.386, year: 2014

  6. Seismic Events in Australia and the Aum Shinrikyo

    Science.gov (United States)

    Hennet, C. B.; van der Vink, G. E.; Harvey, D.

    2002-05-01

    On March 20, 1995 the Aum Shinrikyo terrorist group staged a sarin gas attack in the Tokyo Subway system in Japan that killed 12 and injured 5,000 people. Following the subway attack, the U.S. Senate initiated an investigation into the activities of this previously little known yet powerful religious cult. As part of the investigation, the U.S. Senate's Permanent Subcommittee on Investigations requested the IRIS consortium to determine the nature of a seismic event that occurred in 1993 in a remote part of western Australia, where members of the Aum Shinrikyo cult had been trying to mine uranium and had carried out tests with chemical weapons. The time and location of the seismic event coincided with eyewitness accounts of a low flying, bright object and a large explosion. The analysis of seismic data suggests that the magnitude 3.6 event occurred with a force of up to 2,000 tons of high explosive equivalent, but was unlikely to be an explosive detonation. However, the observations and data could be consistent with the impact of an approximately 3 to 4 meter wide iron meteorite, an event that can be expected to occur on land about every 30 years.

  7. 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

  8. Risks posed by large seismic events in the gold mining districts of South Africa

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2011-01-01

    Full Text Available Examining the occurrence of seismic activity in South Africa, the authors point out that the seismic event on 9 March 2005 could be ascribed to past mining, and that seismic events will continue to occur in the gold mining districts as long as deep...

  9. Seismicity and seismotectonics of the Western Lake Ontario Region -relocation of the seismic events phase III

    International Nuclear Information System (INIS)

    Mohajer, A.A.

    1995-12-01

    Earthquake hazard analysis in Canada relies mainly on recorded earthquake data. The ability to record earthquakes of a given magnitude has varied considerably over time as has the accuracy of location determinations. Recomputation of earthquake locations has been suggested as a possible means of improving the existing data base for better definition of seismic sources. In this study, the locations of more than 50 small to moderate magnitude earthquakes (M≤5), in the western Lake Ontario region, were examined. Available seismograph records in the Record Centre of the National Archives of Canada were examined for events that occurred prior to 1978. The events recorded after this date showed increasing accuracy in their location determinations due to initiation and improvements of the Eastern Canada Telemetry Network (ECTN). Data compiled from the study are based on the relocated and/or selected events with the minimum travel time residuals at the Canadian and American stations. Except for a few scattered events in the south-central part of the Lake Ontario region, microearthquakes (M<3.5) cluster along or at the intersection of prominent aeromagnetic and gravity anomalies, within the Toronto-Hamilton Seismic Zone. This is indicative of certain seismotectonic relationships in this region. The depth distribution or the better located events show that a range of 5 to 20 km is dominant and, therefore, they are not near-surface stress relief phenomena. However, details of the structural manifestation of inferred seismogenic features need further ground truthing, backed by long term seismic monitoring. (author) 66 refs., 3 tabs., 6 figs

  10. 6C polarization analysis - seismic direction finding in coherent noise, automated event identification, and wavefield separation

    Science.gov (United States)

    Schmelzbach, C.; Sollberger, D.; Greenhalgh, S.; Van Renterghem, C.; Robertsson, J. O. A.

    2017-12-01

    Polarization analysis of standard three-component (3C) seismic data is an established tool to determine the propagation directions of seismic waves recorded by a single station. A major limitation of seismic direction finding methods using 3C recordings, however, is that a correct propagation-direction determination is only possible if the wave mode is known. Furthermore, 3C polarization analysis techniques break down in the presence of coherent noise (i.e., when more than one event is present in the analysis time window). Recent advances in sensor technology (e.g., fibre-optical, magnetohydrodynamic angular rate sensors, and ring laser gyroscopes) have made it possible to accurately measure all three components of rotational ground motion exhibited by seismic waves, in addition to the conventionally recorded three components of translational motion. Here, we present an extension of the theory of single station 3C polarization analysis to six-component (6C) recordings of collocated translational and rotational ground motions. We demonstrate that the information contained in rotation measurements can help to overcome some of the main limitations of standard 3C seismic direction finding, such as handling multiple arrivals simultaneously. We show that the 6C polarisation of elastic waves measured at the Earth's free surface does not only depend on the seismic wave type and propagation direction, but also on the local P- and S-wave velocities just beneath the recording station. Using an adaptation of the multiple signal classification algorithm (MUSIC), we demonstrate how seismic events can univocally be identified and characterized in terms of their wave type. Furthermore, we show how the local velocities can be inferred from single-station 6C data, in addition to the direction angles (inclination and azimuth) of seismic arrivals. A major benefit of our proposed 6C method is that it also allows the accurate recovery of the wave type, propagation directions, and phase

  11. Dimensional Representation and Gradient Boosting for Seismic Event Classification

    Science.gov (United States)

    Semmelmayer, F. C.; Kappedal, R. D.; Magana-Zook, S. A.

    2017-12-01

    In this research, we conducted experiments of representational structures on 5009 seismic signals with the intent of finding a method to classify signals as either an explosion or an earthquake in an automated fashion. We also applied a gradient boosted classifier. While perfect classification was not attained (approximately 88% was our best model), some cases demonstrate that many events can be filtered out as very high probability being explosions or earthquakes, diminishing subject-matter experts'(SME) workload for first stage analysis. It is our hope that these methods can be refined, further increasing the classification probability.

  12. Using Impactors for Active Seismic Investigation of the Interior of Mars with a Single Seismic Station

    Science.gov (United States)

    Webb, F.; Kedar, S.; Wolf, A.; Harvey, N.; Sklyanskiy, E.; Chu, R.

    2010-12-01

    A mission feasibility study to determine the interior structure of Mars with an active seismic experiment has demonstrated that a single lander with a seismometer placed on Mars and recording signals from several high-energy impactors that strike the planet in different locations can provide valuable information on the interior structure on Mars. A seismic sensitivity analysis was conducted, simulating seismic wave propagation through generic Martian interior models, and using a range of impact seismic efficiency factors and a variety of candidate seismometers. Both regional (~100km) and planet-scale seismic studies were simulated. More than any other factor, the scientific success of the concept depends on the correct assessment of the impact’s seismic efficiency. Our calculations show that a 500Kg projectile, hitting the planet at 5km/s with seismic efficiency of 10-3, will likely be observed at a distance of 50° away from the impact. This concept demonstrates that an active impact experiment could provide additional operational value to Mars seismometry missions.

  13. Simulating spontaneous aseismic and seismic slip events on evolving faults

    Science.gov (United States)

    Herrendörfer, Robert; van Dinther, Ylona; Pranger, Casper; Gerya, Taras

    2017-04-01

    Plate motion along tectonic boundaries is accommodated by different slip modes: steady creep, seismic slip and slow slip transients. Due to mainly indirect observations and difficulties to scale results from laboratory experiments to nature, it remains enigmatic which fault conditions favour certain slip modes. Therefore, we are developing a numerical modelling approach that is capable of simulating different slip modes together with the long-term fault evolution in a large-scale tectonic setting. We extend the 2D, continuum mechanics-based, visco-elasto-plastic thermo-mechanical model that was designed to simulate slip transients in large-scale geodynamic simulations (van Dinther et al., JGR, 2013). We improve the numerical approach to accurately treat the non-linear problem of plasticity (see also EGU 2017 abstract by Pranger et al.). To resolve a wide slip rate spectrum on evolving faults, we develop an invariant reformulation of the conventional rate-and-state dependent friction (RSF) and adapt the time step (Lapusta et al., JGR, 2000). A crucial part of this development is a conceptual ductile fault zone model that relates slip rates along discrete planes to the effective macroscopic plastic strain rates in the continuum. We test our implementation first in a simple 2D setup with a single fault zone that has a predefined initial thickness. Results show that deformation localizes in case of steady creep and for very slow slip transients to a bell-shaped strain rate profile across the fault zone, which suggests that a length scale across the fault zone may exist. This continuum length scale would overcome the common mesh-dependency in plasticity simulations and question the conventional treatment of aseismic slip on infinitely thin fault zones. We test the introduction of a diffusion term (similar to the damage description in Lyakhovsky et al., JMPS, 2011) into the state evolution equation and its effect on (de-)localization during faster slip events. We compare

  14. Leveraging Long-term Seismic Catalogs for Automated Real-time Event Classification

    Science.gov (United States)

    Linville, L.; Draelos, T.; Pankow, K. L.; Young, C. J.; Alvarez, S.

    2017-12-01

    We investigate the use of labeled event types available through reviewed seismic catalogs to produce automated event labels on new incoming data from the crustal region spanned by the cataloged events. Using events cataloged by the University of Utah Seismograph Stations between October, 2012 and June, 2017, we calculate the spectrogram for a time window that spans the duration of each event as seen on individual stations, resulting in 110k event spectrograms (50% local earthquakes examples, 50% quarry blasts examples). Using 80% of the randomized example events ( 90k), a classifier is trained to distinguish between local earthquakes and quarry blasts. We explore variations of deep learning classifiers, incorporating elements of convolutional and recurrent neural networks. Using a single-layer Long Short Term Memory recurrent neural network, we achieve 92% accuracy on the classification task on the remaining 20K test examples. Leveraging the decisions from a group of stations that detected the same event by using the median of all classifications in the group increases the model accuracy to 96%. Additional data with equivalent processing from 500 more recently cataloged events (July, 2017), achieves the same accuracy as our test data on both single-station examples and multi-station medians, suggesting that the model can maintain accurate and stable classification rates on real-time automated events local to the University of Utah Seismograph Stations, with potentially minimal levels of re-training through time.

  15. 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

    analysts. The second technique is that of matched field processing whereby spatial covariance matrices calculated from large numbers of confirmed events from a single site can be used to generate calibrated narrow-band steering vectors which can replace the theoretical plane-wave steering vectors of traditional f-k analysis. This provides a kind of fingerprint which is specific to a given source region and is effective to higher frequencies than traditional beamforming since deviations from the theoretical planewave model are compensated for in the calibrations. The narrow-band nature of the technique makes the source identification most sensitive to the spatial nature of the recorded wavefield and less sensitive to the temporal nature. This may make the method far more suitable for events with very complicated seismic sources than full waveform-correlation methods.

  16. The effect of a single recombination event

    DEFF Research Database (Denmark)

    Schierup, Mikkel Heide; Jensen, Thomas Mailund; Wiuf, Carsten

    We investigate the variance in how visible a single recombination event is in a SNP data set as a function of the type of recombination event and its age. Data is simulated under the coalescent with recombination and inference is by the popular composite likelihood methods. The major determinant...... of the effect of a recombination event is the genealogical type of the event and whether SNP variation is present that can reveal the genealogical consequences of the recombination event. Recombination events that only change some branch lengths in the genealogy have a very small, but detectable, effect....... The more lineages left when the recombination event occurs, the larger effect it has, implying that it is mainly young recombination events that we detect when estimating the rate. If the population is growing, though, more lineages are present back in time and relatively more ancient recombination events...

  17. Evidence of post-seismic creep type deformations derived by tilt and acoustic emission monitoring of mining induced seismic events

    Science.gov (United States)

    Milev, Alexander; Share, Pieter-Ewald; Naoi, Makoto; Durrheim, Raymond; Yabe, Yasuo; Ogasawara, Hiroshi; Nakatani, Masao

    2015-04-01

    In this study we try to understand pre- and post-failure rock behavior associated with mining induced seismic events. This involves underground installation of various high precision instruments, including geophones, acoustic emission sensors, tilt- and strain-meters at a number of sites in deep level South African gold mines. The rate of tilt, strain and the seismic ground motion were analysed in order to understand the coseismic and aseismic deformation of the rocks. A good correspondence between the coseismic and the aseismic deformations was found. The rate of coseismic and aseismic tilt, as well as seismicity recorded by the mine seismic network, are approximately constant until the daily blasting time, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events, the coseismic tilt and strain shows a rapid increase. Much of the aseismic deformation, however, occurs independently of the seismic events and blasting. In an attempt to distinguish between the different mechanisms of tilting two types of events were recognized. The "fast" seismic events characterized with sharp increase of the tilt during the seismic rupture and "slow" seismic events characterized by creep type post seismic deformations. Tilt behaviour before and after a seismic event was also analysed. The fact that no recognizable aftertilt was observed for more of the "fast" seismic events means that there is no gradual release of stress and an associated continuous strain rate change afterwards. It can therefore be concluded that a large seismic event causes a rapid change in the state of stress rather than a gradual change in the strain rate During the monitoring period a seismic event with MW 2.2 occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emission network. More than 21,000 AE aftershocks were located in the first 150 hours after the

  18. Mining-induced seismicity at the Lucky Friday Mine: Seismic events of magnitude >2.5, 1989--1994

    Energy Technology Data Exchange (ETDEWEB)

    Whyatt, J.K.; Williams, T.J. [USDOE, Spokane, WA (United States). Spokane Research Center; Blake, W. [Blake (W.), Hayden Lake, ID (United States); Sprenke, K. [Idaho Univ., Moscow, ID (United States); Wideman, C. [Montana Tech, Butte, MT (United States)

    1996-09-01

    An understanding of the types of seismic events that occur in a deep mine provides a foundation for assessing the seismic characteristics of these events and the degree to which initiation of these events can be anticipated or controlled. This study is a first step toward developing such an understanding of seismic events generated by mining in the Coeur d`Alene Mining District of northern Idaho. It is based on information developed in the course of a long-standing rock burst research effort undertaken by the U. S. Bureau of Mines in cooperation with Coeur d`Alene Mining District mines and regional universities. This information was collected for 39 seismic events with local magnitudes greater than 2.5 that occurred between 1989 and 1994. One of these events occurred, on average, every 8 weeks during the study period. Five major types of characteristic events were developed from the data; these five types describe all but two of the 39 events that were studied. The most common types of events occurred, on average, once every 30 weeks. The characteristic mechanisms, first-motion patterns, damage patterns, and relationships to mining and major geologic structures were defined for each type of event. These five types of events need to be studied further to assess their ability to camouflage clandestine nuclear tests as well as the degree to which they can be anticipated and controlled.

  19. Influence of Tidal Forces on the Triggering of Seismic Events

    Science.gov (United States)

    Varga, Péter; Grafarend, Erik

    2017-05-01

    Tidal stresses are generated in any three-dimensional body influenced by an external inhomogeneous gravity field of rotating planets or moons. In this paper, as a special case, stresses caused within the solid Earth by the body tides are discussed from viewpoint of their influence on seismic activity. The earthquake triggering effects of the Moon and Sun are usually investigated by statistical comparison of tidal variations and temporal distribution of earthquake activity, or with the use of mathematical or experimental modelling of physical processes in earthquake prone structures. In this study, the magnitude of the lunisolar stress tensor in terms of its components along the latitude of the spherical surface of the Earth as well as inside the Earth (up to the core-mantle boundary) were calculated for the PREM (Dziewonski and Anderson in Phys Earth Planet Inter 25(4):297-356, 1981). Results of calculations prove that stress increases as a function of depth reaching a value around some kPa at the depth of 900-1500 km, well below the zone of deep earthquakes. At the depth of the overwhelming part of seismic energy accumulation (around 50 km) the stresses of lunisolar origin are only (0.0-1.0)·103 Pa. Despite the fact that these values are much smaller than the earthquake stress drops (1-30 MPa) (Kanamori in Annu Rev Earth Planet Sci 22:207-237, 1994) this does not exclude the possibility of an impact of tidal forces on outbreak of seismic events. Since the tidal potential and its derivatives are coordinate dependent and the zonal, tesseral and sectorial tides have different distributions from the surface down to the CMB, the lunisolar stress cannot influence the break-out of every seismological event in the same degree. The influencing lunisolar effect of the solid earth tides on earthquake occurrences is connected first of all with stress components acting parallel to the surface of the Earth. The influence of load tides is limited to the loaded area and its

  20. Locating seismicity on the Arctic plate boundary using multiple-event techniques and empirical signal processing

    Science.gov (United States)

    Gibbons, S. J.; Harris, D. B.; Dahl-Jensen, T.; Kværna, T.; Larsen, T. B.; Paulsen, B.; Voss, P. H.

    2017-12-01

    The oceanic boundary separating the Eurasian and North American plates between 70° and 84° north hosts large earthquakes which are well recorded teleseismically, and many more seismic events at far lower magnitudes that are well recorded only at regional distances. Existing seismic bulletins have considerable spread and bias resulting from limited station coverage and deficiencies in the velocity models applied. This is particularly acute for the lower magnitude events which may only be constrained by a small number of Pn and Sn arrivals. Over the past two decades there has been a significant improvement in the seismic network in the Arctic: a difficult region to instrument due to the harsh climate, a sparsity of accessible sites (particularly at significant distances from the sea), and the expense and difficult logistics of deploying and maintaining stations. New deployments and upgrades to stations on Greenland, Svalbard, Jan Mayen, Hopen, and Bjørnøya have resulted in a sparse but stable regional seismic network which results in events down to magnitudes below 3 generating high-quality Pn and Sn signals on multiple stations. A catalogue of several hundred events in the region since 1998 has been generated using many new phase readings on stations on both sides of the spreading ridge in addition to teleseismic P phases. A Bayesian multiple event relocation has resulted in a significant reduction in the spread of hypocentre estimates for both large and small events. Whereas single event location algorithms minimize vectors of time residuals on an event-by-event basis, the Bayesloc program finds a joint probability distribution of origins, hypocentres, and corrections to traveltime predictions for large numbers of events. The solutions obtained favour those event hypotheses resulting in time residuals which are most consistent over a given source region. The relocations have been performed with different 1-D velocity models applicable to the Arctic region and

  1. A probabilistic framework for single-station location of seismicity on Earth and Mars

    Science.gov (United States)

    Böse, M.; Clinton, J. F.; Ceylan, S.; Euchner, F.; van Driel, M.; Khan, A.; Giardini, D.; Lognonné, P.; Banerdt, W. B.

    2017-01-01

    Locating the source of seismic energy from a single three-component seismic station is associated with large uncertainties, originating from challenges in identifying seismic phases, as well as inevitable pick and model uncertainties. The challenge is even higher for planets such as Mars, where interior structure is a priori largely unknown. In this study, we address the single-station location problem by developing a probabilistic framework that combines location estimates from multiple algorithms to estimate the probability density function (PDF) for epicentral distance, back azimuth, and origin time. Each algorithm uses independent and complementary information in the seismic signals. Together, the algorithms allow locating seismicity ranging from local to teleseismic quakes. Distances and origin times of large regional and teleseismic events (M > 5.5) are estimated from observed and theoretical body- and multi-orbit surface-wave travel times. The latter are picked from the maxima in the waveform envelopes in various frequency bands. For smaller events at local and regional distances, only first arrival picks of body waves are used, possibly in combination with fundamental Rayleigh R1 waveform maxima where detectable; depth phases, such as pP or PmP, help constrain source depth and improve distance estimates. Back azimuth is determined from the polarization of the Rayleigh- and/or P-wave phases. When seismic signals are good enough for multiple approaches to be used, estimates from the various methods are combined through the product of their PDFs, resulting in an improved event location and reduced uncertainty range estimate compared to the results obtained from each algorithm independently. To verify our approach, we use both earthquake recordings from existing Earth stations and synthetic Martian seismograms. The Mars synthetics are generated with a full-waveform scheme (AxiSEM) using spherically-symmetric seismic velocity, density and attenuation models of

  2. Detecting Earthquakes over a Seismic Network using Single-Station Similarity Measures

    Science.gov (United States)

    Bergen, Karianne J.; Beroza, Gregory C.

    2018-03-01

    New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected move-out. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to two weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalog (including 95% of the catalog events), and less than 1% of these candidate events are false detections.

  3. Single event phenomena in atmospheric neutron environments

    International Nuclear Information System (INIS)

    Gossett, C.A.; Hughlock, B.W.; Katoozi, M.; LaRue, G.S.; Wender, S.A.

    1993-01-01

    As integrated circuit technology achieves higher density through smaller feature sizes and as the airplane manufacturing industry integrates more sophisticated electronic components into the design of new aircraft, it has become increasingly important to evaluate the contribution of single event effects, primarily Single Event Upset (SEU), to the safety and reliability of commercial aircraft. In contrast to the effects of radiation on electronic systems in space applications for which protons and heavy ions are of major concern, in commercial aircraft applications the interactions of high energy neutrons are the dominant cause of single event effects. These high energy neutrons are produced by the interaction of solar and galactic cosmic rays, principally protons and heavy ions, in the upper atmosphere. This paper will describe direct experimental measurements of neutron-induced Single Event Effect (SEE) rates in commercial high density static random access memories in a neutron environment characteristic of that at commercial airplane altitudes. The first experimental measurements testing current models for neutron-silicon burst generation rates will be presented, as well as measurements of charge collection in silicon test structures as a function of neutron energy. These are the first laboratory SEE and charge collection measurements using a particle beam having a continuum energy spectrum and with a shape nearly identical to that observed during flight

  4. New seismic events identified in the Apollo lunar data by application of a Hidden Markov Model

    Science.gov (United States)

    Knapmeyer-Endrun, B.; Hammer, C.

    2015-10-01

    The Apollo astronauts installed seismic stations on the Moon during Apollo missions 11, 12, 14, 15 and 16. The stations consisted of a three-component long- period seismometer (eigenperiod 15 s) and a vertical short-period sensor (eigenperiod 1 s). Until today, the Apollo seismic network provides the only confirmed recordings of seismic events from any extrater-restrial. The recorded event waveforms differ significantly from what had been expected based on Earth data, mainly by their long duration body wave codas caused by strong near-surface scattering and weak attenuation due to lack of fluids. The main lunar event types are deep moonquakes, impacts, and the rare shallow moonquakes.

  5. Study of local seismic events in Lithuania and adjacent areas using data from the PASSEQ experiment

    Czech Academy of Sciences Publication Activity Database

    Janutyte, I.; Kozlovskaya, E.; Motuza, G.; Plomerová, Jaroslava; Babuška, Vladislav; Gaždová, Renata; Jedlička, Petr; Kolínský, Petr; Málek, Jiří; Novotný, Oldřich; Růžek, Bohuslav

    2013-01-01

    Roč. 170, č. 5 (2013), s. 797-814 ISSN 0033-4553 Institutional support: RVO:67985530 ; RVO:67985891 Keywords : location of local seismic events * East European Craton * PASSEQ passive seismic experiment Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.854, year: 2013

  6. Examples of anomalies of the radon 222 like precursor of seismic events in Costa Rica

    International Nuclear Information System (INIS)

    Garcia Vindas, J.R.; Loria M, L.G.; Jimenez Dam, R.

    2000-01-01

    The relation between seismicity and Radon 222 concentration anomalies has been studied. The changes in the gas concentration are considered as precursors of the seismic events. This study illustrates the before mentioned relation and confirms that aquifers are favorable places for radon monitoring. (Author) [es

  7. Error Analysis in the Joint Event Location/Seismic Calibration Inverse Problem

    National Research Council Canada - National Science Library

    Rodi, William L

    2006-01-01

    This project is developing new mathematical and computational techniques for analyzing the uncertainty in seismic event locations, as induced by observational errors and errors in travel-time models...

  8. Early Warning System for Seismic Events in Coal Mines Using Machine Learning

    OpenAIRE

    Bogucki, Robert; Lasek, Jan; Milczek, Jan Kanty; Tadeusiak, Michal

    2016-01-01

    This document describes an approach to the problem of predicting dangerous seismic events in active coal mines up to 8 hours in advance. It was developed as a part of the AAIA'16 Data Mining Challenge: Predicting Dangerous Seismic Events in Active Coal Mines. The solutions presented consist of ensembles of various predictive models trained on different sets of features. The best one achieved a winning score of 0.939 AUC.

  9. Experimental Setups for Single Event Effect Studies

    OpenAIRE

    N. H. Medina; V. A. P. Aguiar; N. Added; F. Aguirre; E. L. A. Macchione; S. G. Alberton; M. A. G. Silveira; J. Benfica; F. Vargas; B. Porcher

    2016-01-01

    Experimental setups are being prepared to test and to qualify electronic devices regarding their tolerance to Single Event Effect (SEE). A multiple test setup and a new beam line developed especially for SEE studies at the São Paulo 8 UD Pelletron accelerator were prepared. This accelerator produces proton beams and heavy ion beams up to 107Ag. A Super conducting Linear accelerator, which is under construction, may fulfill all of the European Space Agency requirements to qualify electronic...

  10. Seismic Phase amplitude decay and implications for event detection rates on Mars

    Science.gov (United States)

    Knapmeyer, M.; Weber, R. C.; Lognonné, P.

    2008-09-01

    The number of seismic events detected by a seismometer during a certain interval of time depends on the sensitivity of the instrument, the level and spatial distribution of seismic activity of the planet, and the internal structure and composition of the planet. The latter controls the focusing/scattering of the seismic waves and their attenuation. We estimate detection rates that can be expected from the ExoMars-Seismometer. We use a Martian seismicity model to estimate the number, size and distribution of marsquakes, and calculate event amplitudes from synthetic seismograms computed using normal mode summation in a standard structure model of Mars. In combination with the expected life times and the known sensitivities of the sensors used in the ExoMars SEIS experiment, we aim to map the expected detection rates for several seismic phases as function of landing site coordinates and to simulate the expected scientific data return from a Seismometer on a given site.

  11. 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.)

  12. Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    K. Coppersmith; R. Quittmeyer

    2005-02-16

    This report describes a scientific analysis to bound credible horizontal peak ground velocities (PGV) for the repository waste emplacement level at Yucca Mountain. Results are presented as a probability distribution for horizontal PGV to represent uncertainties in the analysis. The analysis also combines the bound to horizontal PGV with results of ground motion site-response modeling (BSC 2004 [DIRS 170027]) to develop a composite hazard curve for horizontal PGV at the waste emplacement level. This result provides input to an abstraction of seismic consequences (BSC 2004 [DIRS 169183]). The seismic consequence abstraction, in turn, defines the input data and computational algorithms for the seismic scenario class of the total system performance assessment (TSPA). Planning for the analysis is documented in Technical Work Plan TWP-MGR-GS-000001 (BSC 2004 [DIRS 171850]). The bound on horizontal PGV at the repository waste emplacement level developed in this analysis complements ground motions developed on the basis of PSHA results. In the PSHA, ground motion experts characterized the epistemic uncertainty and aleatory variability in their ground motion interpretations. To characterize the aleatory variability they used unbounded lognormal distributions. As a consequence of these characterizations, as seismic hazard calculations are extended to lower and lower annual frequencies of being exceeded, the ground motion level increases without bound, eventually reaching levels that are not credible (Corradini 2003 [DIRS 171191]). To provide credible seismic inputs for TSPA, in accordance with 10 Code of Federal Regulations (CFR) 63.102(j) [DIRS 156605], this complementary analysis is carried out to determine reasonable bounding values of horizontal PGV at the waste emplacement level for annual frequencies of exceedance as low as 10{sup -8}. For each realization of the TSPA seismic scenario, the results of this analysis provide a constraint on the values sampled from the

  13. Dual Interlocked Logic for Single-Event Transient Mitigation

    Science.gov (United States)

    2017-03-01

    Dual Interlocked Logic for Single -Event Transient Mitigation Jeffrey Maharrey, Jeffrey Kauppila, Dennis Ball, Timothy Holman, Lloyd Massengill...is shown to be robust to single event transients. Keywords: SET; CVSL; DIL; single event transient; hardened logic; cascode voltage switch; dual...interlocked Introduction Single event transients (SETs) generated in combinational logic are a major, often dominant, contributor to soft errors in

  14. Processing of Mining Induced Seismic Events by Spectra Analyzer Software

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Lednická, Markéta; Lyubushin, A. A.

    2011-01-01

    Roč. 6, č. 1 (2011), s. 75-83 ISSN 1896-3145. [Ochrona środowiska w górnictwie podziemnym, odkrywkowym i otworowym. Walbrzych, 18.05.2011-20.05.2011] Institutional research plan: CEZ:AV0Z30860518 Keywords : mining seismicity * Spectra Analyzer Software * wavelet decomposition * time-frequency map Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  15. Single event upsets correlated with environment

    International Nuclear Information System (INIS)

    Vampola, A.L.; Albin, F.; Lauriente, M.; Wilkinson, D.C.; Allen, J.

    1994-01-01

    Single Event Upset rates on satellites in different Earth orbits are correlated with solar protons and geomagnetic activity and also with the NASA AP8 proton model to extract information about satellite anomalies caused by the space environment. An extensive discussion of the SEU data base from the TOMS solid state recorder and an algorithm for correcting spontaneous upsets in it are included as an Appendix. SAMPEX and TOMS, which have the same memory chips, have similar normalized responses in the South Atlantic Anomaly. SEU rates due to solar protons over the polar caps are within expectations. No geomagnetic activity effects can be discerned in the SEU rates

  16. Single event upsets in spacecraft digital systems

    Science.gov (United States)

    Leukowicz, P. E.; Richter, L. J.

    This paper describes the physical environments that can result in random bit changes in spaceborne memory systems. The impact of bit flips in digital telemetry systems is emphasized, with special attention paid to software requirements for protection from single event upset (SEU) effects. Some observations on incidence rates are presented along with an outline of hardware and software methods that can be taken to prevent future SEU problems. Several conclusions are drawn about strategies for preventing data corruption on the next generation of satellites in the presence of SEU-inducing particles.

  17. Fully Autonomous Multiplet Event Detection: Application to Local-Distance Monitoring of Blood Falls Seismicity

    Energy Technology Data Exchange (ETDEWEB)

    Carmichael, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, Christina [Univ. of Alaska, Fairbanks, AK (United States); Pettit, Erin C. [Univ. of Alaska, Fairbanks, AK (United States)

    2015-06-18

    We apply a fully autonomous icequake detection methodology to a single day of high-sample rate (200 Hz) seismic network data recorded from the terminus of Taylor Glacier, ANT that temporally coincided with a brine release episode near Blood Falls (May 13, 2014). We demonstrate a statistically validated procedure to assemble waveforms triggered by icequakes into populations of clusters linked by intra-event waveform similarity. Our processing methodology implements a noise-adaptive power detector coupled with a complete-linkage clustering algorithm and noise-adaptive correlation detector. This detector-chain reveals a population of 20 multiplet sequences that includes ~150 icequakes and produces zero false alarms on the concurrent, diurnally variable noise. Our results are very promising for identifying changes in background seismicity associated with the presence or absence of brine release episodes. We thereby suggest that our methodology could be applied to longer time periods to establish a brine-release monitoring program for Blood Falls that is based on icequake detections.

  18. Sequential combination of multi-source satellite observations for separation of surface deformation associated with serial seismic events

    Science.gov (United States)

    Chen, Qiang; Xu, Qian; Zhang, Yijun; Yang, Yinghui; Yong, Qi; Liu, Guoxiang; Liu, Xianwen

    2018-03-01

    Single satellite geodetic technique has weakness for mapping sequence of ground deformation associated with serial seismic events, like InSAR with long revisiting period readily leading to mixed complex deformation signals from multiple events. It challenges the observation capability of single satellite geodetic technique for accurate recognition of individual surface deformation and earthquake model. The rapidly increasing availability of various satellite observations provides good solution for overcoming the issue. In this study, we explore a sequential combination of multiple overlapping datasets from ALOS/PALSAR, ENVISAT/ASAR and GPS observations to separate surface deformation associated with the 2011 Mw 9.0 Tohoku-Oki major quake and two strong aftershocks including the Mw 6.6 Iwaki and Mw 5.8 Ibaraki events. We first estimate the fault slip model of major shock with ASAR interferometry and GPS displacements as constraints. Due to the used PALSAR interferogram spanning the period of all the events, we then remove the surface deformation of major shock through forward calculated prediction thus obtaining PALSAR InSAR deformation associated with the two strong aftershocks. The inversion for source parameters of Iwaki aftershock is conducted using the refined PALSAR deformation considering that the higher magnitude Iwaki quake has dominant deformation contribution than the Ibaraki event. After removal of deformation component of Iwaki event, we determine the fault slip distribution of Ibaraki shock using the remained PALSAR InSAR deformation. Finally, the complete source models for the serial seismic events are clearly identified from the sequential combination of multi-source satellite observations, which suggest that the major quake is a predominant mega-thrust rupture, whereas the two aftershocks are normal faulting motion. The estimated seismic moment magnitude for the Tohoku-Oki, Iwaki and Ibaraki evens are Mw 9.0, Mw 6.85 and Mw 6.11, respectively.

  19. High-resolution seismic event detection using local similarity for Large-N arrays.

    Science.gov (United States)

    Li, Zefeng; Peng, Zhigang; Hollis, Dan; Zhu, Lijun; McClellan, James

    2018-01-26

    We develop a novel method for seismic event detection that can be applied to large-N arrays. The method is based on a new detection function named local similarity, which quantifies the signal consistency between the examined station and its nearest neighbors. Using the 5200-station Long Beach nodal array, we demonstrate that stacked local similarity functions can be used to detect seismic events with amplitudes near or below noise levels. We apply the method to one-week continuous data around the 03/11/2011 Mw 9.1 Tohoku-Oki earthquake, to detect local and distant events. In the 5-10 Hz range, we detect various events of natural and anthropogenic origins, but without a clear increase in local seismicity during and following the surface waves of the Tohoku-Oki mainshock. In the 1-Hz low-pass-filtered range, we detect numerous events, likely representing aftershocks from the Tohoku-Oki mainshock region. This high-resolution detection technique can be applied to both ultra-dense and regular array recordings for monitoring ultra-weak micro-seismicity and detecting unusual seismic events in noisy environments.

  20. Laboratory tests for single-event effects

    International Nuclear Information System (INIS)

    Buchner, S.; McMorrow, D.; Melinger, J.; Campbell, A.B.

    1996-01-01

    Integrated circuits are currently tested at accelerators for their susceptibility to single-event effects (SEE's). However, because of the cost and limited accessibility associated with accelerator testing, there is considerable interest in developing alternate testing methods. Two laboratory techniques for measuring SEE, one involving a pulsed laser and the other 252 Cf, are described in detail in this paper. The pulsed laser provides information on the spatial and temporal dependence of SEE, information that has proven invaluable in understanding and mitigating SEE in spite of the differences in the physical mechanisms responsible for SEE induced by light and by ions. Considerable effort has been expended on developing 252 Cf as a laboratory test for SEE, but the technique has not found wide use because it is severely limited by the low energy and short range of the emitted ions that are unable to reach junctions either covered with dielectric layers or deep below the surface. In fact, there are documented cases where single-event latchup (SEL) testing with 252 Cf gave significantly different results from accelerator testing. A detailed comparison of laboratory and accelerator SEE data is presented in this review in order to establish the limits of each technique

  1. Improving Single Event Effects Testing Through Software

    Science.gov (United States)

    Banker, M. W.

    2011-01-01

    Radiation encountered in space environments can be damaging to microelectronics and potentially cause spacecraft failure. Single event effects (SEE) are a type of radiation effect that occur when an ion strikes a device. Single event gate rupture (SEGR) is a type of SEE that can cause failure in power transistors. Unlike other SEE rates in which a constant linear energy transfer (LET) can be used, SEGR rates sometimes require a non-uniform LET to be used to be accurate. A recent analysis shows that SEGR rates are most easily calculated when the environment is described as a stopping rate per unit volume for each ion species. Stopping rates in silicon for pertinent ions were calculated using the Stopping and Range of Ions in Matter (SRIM) software and CREME-MC software. A reference table was generated and can be used by others to calculate SEGR rates for a candidate device. Additionally, lasers can be used to simulate SEEs, providing more control and information at lower cost than heavy ion testing. The electron/hole pair generation rate from a laser pulse in a semiconductor can be related to the LET of an ion. MATLAB was used to generate a plot to easily make this comparison.

  2. Sources of Error and the Statistical Formulation of M S: m b Seismic Event Screening Analysis

    Science.gov (United States)

    Anderson, D. N.; Patton, H. J.; Taylor, S. R.; Bonner, J. L.; Selby, N. D.

    2014-03-01

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global ban on nuclear explosions, is currently in a ratification phase. Under the CTBT, an International Monitoring System (IMS) of seismic, hydroacoustic, infrasonic and radionuclide sensors is operational, and the data from the IMS is analysed by the International Data Centre (IDC). The IDC provides CTBT signatories basic seismic event parameters and a screening analysis indicating whether an event exhibits explosion characteristics (for example, shallow depth). An important component of the screening analysis is a statistical test of the null hypothesis H 0: explosion characteristics using empirical measurements of seismic energy (magnitudes). The established magnitude used for event size is the body-wave magnitude (denoted m b) computed from the initial segment of a seismic waveform. IDC screening analysis is applied to events with m b greater than 3.5. The Rayleigh wave magnitude (denoted M S) is a measure of later arriving surface wave energy. Magnitudes are measurements of seismic energy that include adjustments (physical correction model) for path and distance effects between event and station. Relative to m b, earthquakes generally have a larger M S magnitude than explosions. This article proposes a hypothesis test (screening analysis) using M S and m b that expressly accounts for physical correction model inadequacy in the standard error of the test statistic. With this hypothesis test formulation, the 2009 Democratic Peoples Republic of Korea announced nuclear weapon test fails to reject the null hypothesis H 0: explosion characteristics.

  3. Experimental study of single event burnout and single event gate rupture in power MOSFETs and IGBT

    International Nuclear Information System (INIS)

    Tang Benqi; Wang Yanping; Geng Bin

    2001-01-01

    An experimental study was carried out to determine the single event burnout and single event gate rupture sensitivities in power MOSFETs and IGBT which were exposed to heavy ions from 252 Cf source. The test method, test results, a description of observed burnout current waveforms and a discussion of a possible failure mechanism were presented. Current measurements have been performed with a specially designed circuit. The test results include the observed dependence upon applied drain or gate to source bias and versus with external capacitors and limited resistors

  4. Development of Simplified Probabilistic Risk Assessment Model for Seismic Initiating Event

    Energy Technology Data Exchange (ETDEWEB)

    S. Khericha; R. Buell; S. Sancaktar; M. Gonzalez; F. Ferrante

    2012-06-01

    ABSTRACT This paper discusses a simplified method to evaluate seismic risk using a methodology built on dividing the seismic intensity spectrum into multiple discrete bins. The seismic probabilistic risk assessment model uses Nuclear Regulatory Commission’s (NRC’s) full power Standardized Plant Analysis Risk (SPAR) model as the starting point for development. The seismic PRA models are integrated with their respective internal events at-power SPAR model. This is accomplished by combining the modified system fault trees from the full power SPAR model with seismic event tree logic. The peak ground acceleration is divided into five bins. The g-value for each bin is estimated using the geometric mean of lower and upper values of that particular bin and the associated frequency for each bin is estimated by taking the difference between upper and lower values of that bin. The component’s fragilities are calculated for each bin using the plant data, if available, or generic values of median peak ground acceleration and uncertainty values for the components. For human reliability analysis (HRA), the SPAR HRA (SPAR-H) method is used which requires the analysts to complete relatively straight forward worksheets that include the performance shaping factors (PSFs). The results are then used to estimate human error probabilities (HEPs) of interest. This work is expected to improve the NRC’s ability to include seismic hazards in risk assessments for operational events in support of the reactor oversight program (e.g., significance determination process).

  5. Analysis of the Seismic Events Apparently Associated with the 3 September 2017 DPRK Declared Nuclear Explosion

    Science.gov (United States)

    Walter, W. R.; Dodge, D. A.; Ichinose, G.; Myers, S. C.; Ford, S. R.; Pitarka, A.; Pyle, M. L.; Pasyanos, M.; Matzel, E.; Rodgers, A. J.; Mellors, R. J.; Hauk, T. F.; Kroll, K.

    2017-12-01

    On September 3, 2017, an mb 6.3 seismic event was reported by the USGS in the vicinity of the DPRK nuclear test site at Punggye-ri. Shortly afterwards DPRK declared it had conducted a nuclear explosion. The seismic signals indicate this event is roughly an order of magnitude larger than the largest of the previous five DPRK declared nuclear tests. In addition to its size, this explosion was different from previous DPRK tests in being associated with a number of additional seismic events. Approximately eight and a half minutes after the explosion a seismic event reported as ML 4.0 by the USGS occurred. Regional waveform modeling indicated this event had a collapse mechanism (e.g. Ichinose et al., 2017, written communication). On September 23 and again on October 12, 2017, seismic events were reported near the DPRK test site by the USGS and the CTBTO (on 9/23/17 two events: USGS ML 3.6 and USGS ML 2.6; and on 10/12/17 one event: USGS mb(Lg) 2.9). Aftershocks following underground nuclear testing are expected, though at much lower magnitudes and rates than for comparably sized earthquakes. This difference in aftershock production has been proposed by Ford and Walter (2010), and others as a potential source-type discriminant. Seismic signals from the collapse of cavities formed by underground nuclear testing have also been previously observed. For example, the mb 5.7 nuclear test ATRISCO in Nevada in 1982 was followed twenty minutes later by a collapse with an mb of 4.0. Here we examine the seismic characteristics of nuclear tests, post-test collapses and post-test aftershocks from both the former Nevada test site and the DPRK test site to better understand the differences between these different source-type signals. In particular we look at discriminants such as P/S ratios, to see if there are unique characteristics to post-test collapses and aftershocks. Finally, we apply correlation methods to continuous data at regional stations to look for additional seismic

  6. Seismic constraints on a large dyking event in Western Gulf of Aden

    Science.gov (United States)

    Ahmed, A.; Doubre, C.; Leroy, S.; Perrot, J.; Audin, L.; Rolandone, F.; Keir, D.; Al-Ganad, I.; Khanbari, K.; Mohamed, K.; Vergne, J.; Jacques, E.; Nercessian, A.

    2012-04-01

    In November 2010, a large number of events were recorded by the world seismic networks showing important activity occurring along the western part of the Aden Ridge. West of the Shulka El Sheik transform zone, events in this large seismic swarm (magnitudes above 5) occurred in a complex area, where the change of both the ridge direction and the bathymetry suggest the propagation of the ridge into a continental lithosphere and the influence of the thermal anomaly of the Afar Hot Spot. We combine several sets of data from permanent networks and temporary 3C broad stations installed after the beginning of the event along the southern and eastern coasts of Yemen and Djibouti respectively, we located more than 600 earthquakes with magnitudes ranging from 2.5 to 5.6 that occurred during the first months following the first event. The spatial distribution of the main seismicity reveals a very clear N115°-trending alignment, parallel to the mean direction of the en-echelon spreading segments that form the ridge at this longitude. Half of the events, which represent half of the total seismic energy released during the first months, are located in the central third section of the segment. Here several volcanic cones and recent lava flows observed from bathymetric and acoustic reflectivity data during the Tadjouraden cruise (Audin, 1999, Dauteuil et al., 2001) constitute the sea floor. In addition to this main activity, two small groups of events suggest the activiation of landslides into a large fan and the activity in a volcanic area 50 km due east from the main active zone. The time evolution of the seismicity shows several bursts of activity. Some of them are clearly related to sudden activities within the volcanic areas, when others exhibit horizontal migration of the events, with velocity around ~ 1 km/h. The time-space evolution of the seismicity clearly reveals the intrusion of dykes associated with magma propagation from the crustal magmatic centres into the rift

  7. Single Event Effect (SEE) Test Planning 101

    Science.gov (United States)

    LaBel, Kenneth A.; Pellish, Jonathan; Berg, Melanie D.

    2011-01-01

    This is a course on SEE Test Plan development. It is an introductory discussion of the items that go into planning an SEE test that should complement the SEE test methodology used. Material will only cover heavy ion SEE testing and not proton, LASER, or other though many of the discussed items may be applicable. While standards and guidelines for how-to perform single event effects (SEE) testing have existed almost since the first cyclotron testing, guidance on the development of SEE test plans has not been as easy to find. In this section of the short course, we attempt to rectify this lack. We consider the approach outlined here as a "living" document: mission specific constraints and new technology related issues always need to be taken into account. We note that we will use the term "test planning" in the context of those items being included in a test plan.

  8. An Updated Perspective of Single Event Gate Rupture and Single Event Burnout in Power MOSFETs

    Science.gov (United States)

    Titus, Jeffrey L.

    2013-06-01

    Studies over the past 25 years have shown that heavy ions can trigger catastrophic failure modes in power MOSFETs [e.g., single-event gate rupture (SEGR) and single-event burnout (SEB)]. In 1996, two papers were published in a special issue of the IEEE Transaction on Nuclear Science [Johnson, Palau, Dachs, Galloway and Schrimpf, “A Review of the Techniques Used for Modeling Single-Event Effects in Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 546-560, April. 1996], [Titus and Wheatley, “Experimental Studies of Single-Event Gate Rupture and Burnout in Vertical Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 533-545, Apr. 1996]. Those two papers continue to provide excellent information and references with regard to SEB and SEGR in vertical planar MOSFETs. This paper provides updated references/information and provides an updated perspective of SEB and SEGR in vertical planar MOSFETs as well as provides references/information to other device types that exhibit SEB and SEGR effects.

  9. Automatic Classification of volcano-seismic events based on Deep Neural Networks.

    Science.gov (United States)

    Titos Luzón, M.; Bueno Rodriguez, A.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

    2017-12-01

    Seismic monitoring of active volcanoes is a popular remote sensing technique to detect seismic activity, often associated to energy exchanges between the volcano and the environment. As a result, seismographs register a wide range of volcano-seismic signals that reflect the nature and underlying physics of volcanic processes. Machine learning and signal processing techniques provide an appropriate framework to analyze such data. In this research, we propose a new classification framework for seismic events based on deep neural networks. Deep neural networks are composed by multiple processing layers, and can discover intrinsic patterns from the data itself. Internal parameters can be initialized using a greedy unsupervised pre-training stage, leading to an efficient training of fully connected architectures. We aim to determine the robustness of these architectures as classifiers of seven different types of seismic events recorded at "Volcán de Fuego" (Colima, Mexico). Two deep neural networks with different pre-training strategies are studied: stacked denoising autoencoder and deep belief networks. Results are compared to existing machine learning algorithms (SVM, Random Forest, Multilayer Perceptron). We used 5 LPC coefficients over three non-overlapping segments as training features in order to characterize temporal evolution, avoid redundancy and encode the signal, regardless of its duration. Experimental results show that deep architectures can classify seismic events with higher accuracy than classical algorithms, attaining up to 92% recognition accuracy. Pre-training initialization helps these models to detect events that occur simultaneously in time (such explosions and rockfalls), increase robustness against noisy inputs, and provide better generalization. These results demonstrate deep neural networks are robust classifiers, and can be deployed in real-environments to monitor the seismicity of restless volcanoes.

  10. WILBER and PyWEED: Event-based Seismic Data Request Tools

    Science.gov (United States)

    Falco, N.; Clark, A.; Trabant, C. M.

    2017-12-01

    WILBER and PyWEED are two user-friendly tools for requesting event-oriented seismic data. Both tools provide interactive maps and other controls for browsing and filtering event and station catalogs, and downloading data for selected event/station combinations, where the data window for each event/station pair may be defined relative to the arrival time of seismic waves from the event to that particular station. Both tools allow data to be previewed visually, and can download data in standard miniSEED, SAC, and other formats, complete with relevant metadata for performing instrument correction. WILBER is a web application requiring only a modern web browser. Once the user has selected an event, WILBER identifies all data available for that time period, and allows the user to select stations based on criteria such as the station's distance and orientation relative to the event. When the user has finalized their request, the data is collected and packaged on the IRIS server, and when it is ready the user is sent a link to download. PyWEED is a downloadable, cross-platform (Macintosh / Windows / Linux) application written in Python. PyWEED allows a user to select multiple events and stations, and will download data for each event/station combination selected. PyWEED is built around the ObsPy seismic toolkit, and allows direct interaction and control of the application through a Python interactive console.

  11. Analysis of rockburst and rockfall accidents in relation to class of stope support, regional support, energy of seismic events and mining layout

    CSIR Research Space (South Africa)

    Cichowicz, A

    1994-01-01

    Full Text Available This report discusses the assessment of safety risk and the analysis of Falls Of Ground (FOG) in mines due to seismic events and mining layout during the period of 1991-1992 on a single mine. The multivariate analysis was used to obtain a...

  12. Supervised machine learning on a network scale: application to seismic event classification and detection

    Science.gov (United States)

    Reynen, Andrew; Audet, Pascal

    2017-09-01

    A new method using a machine learning technique is applied to event classification and detection at seismic networks. This method is applicable to a variety of network sizes and settings. The algorithm makes use of a small catalogue of known observations across the entire network. Two attributes, the polarization and frequency content, are used as input to regression. These attributes are extracted at predicted arrival times for P and S waves using only an approximate velocity model, as attributes are calculated over large time spans. This method of waveform characterization is shown to be able to distinguish between blasts and earthquakes with 99 per cent accuracy using a network of 13 stations located in Southern California. The combination of machine learning with generalized waveform features is further applied to event detection in Oklahoma, United States. The event detection algorithm makes use of a pair of unique seismic phases to locate events, with a precision directly related to the sampling rate of the generalized waveform features. Over a week of data from 30 stations in Oklahoma, United States are used to automatically detect 25 times more events than the catalogue of the local geological survey, with a false detection rate of less than 2 per cent. This method provides a highly confident way of detecting and locating events. Furthermore, a large number of seismic events can be automatically detected with low false alarm, allowing for a larger automatic event catalogue with a high degree of trust.

  13. Seismic events and their impacts on water infrastructure in a large urban conglomeration

    Science.gov (United States)

    Francisca Naranjo, Maria

    2013-04-01

    The objective of this work is to show a few examples of water-related hazards in urban zones subjected to seismic hazards. We present the case of Mexico City, an urban conglomeration with more than 20 million inhabitants, with soil subsidence due to excessive groundwater pumping and prone to a historical earthquake incidence (in magnitude and cost-damages). Past significant seismic events and their impacts on the water supply and sewage network are analyzed. Likewise, potential material and economic losses that the urban water network could face in case of an extreme earthquake are shown. Finally, cost-effective solutions are proposed in order to reduce water-related risks over the short and medium term following a seismic event of substantial magnitude.

  14. Coseismic and aseismic deformations associated with mining-induced seismic events located in deep level mines in South Africa

    CSIR Research Space (South Africa)

    Milev, A

    2013-10-01

    Full Text Available ), South Africa, RDurrhei@csir.co.za 4. Ritsumeikan University, Japan, ogasawar@se.ritsumei.ac.jp 5. ERI, Tokyo University, Japan, nakatani@eri.u-tokyo.ac.jp 6. Tohoku University, Japan, yabe@aob.gp.tohoku.ac.jp INTRODUCTION Seismicity... slip CONCLUSIONS Tilt increases rapidly during seismic events and blasting. This type of changes was described as “fast” seismic events. However, a great deal of deformation was found to occur independently of seismic events and were described...

  15. Equivalent properties of single event burnout induced by different sources

    International Nuclear Information System (INIS)

    Yang Shiyu; Cao Zhou; Da Daoan; Xue Yuxiong

    2009-01-01

    The experimental results of single event burnout induced by heavy ions and 252 Cf fission fragments in power MOSFET devices have been investigated. It is concluded that the characteristics of single event burnout induced by 252 Cf fission fragments is consistent to that in heavy ions. The power MOSFET in the 'turn-off' state is more susceptible to single event burnout than it is in the 'turn-on' state. The thresholds of the drain-source voltage for single event burnout induced by 173 MeV bromine ions and 252 Cf fission fragments are close to each other, and the burnout cross section is sensitive to variation of the drain-source voltage above the threshold of single event burnout. In addition, the current waveforms of single event burnouts induced by different sources are similar. Different power MOSFET devices may have different probabilities for the occurrence of single event burnout. (authors)

  16. Seismic Design of a Single Bored Tunnel: Longitudinal Deformations and Seismic Joints

    Science.gov (United States)

    Oh, J.; Moon, T.

    2018-03-01

    The large diameter bored tunnel passing through rock and alluvial deposits subjected to seismic loading is analyzed for estimating longitudinal deformations and member forces on the segmental tunnel liners. The project site has challenges including high hydrostatic pressure, variable ground profile and high seismic loading. To ensure the safety of segmental tunnel liner from the seismic demands, the performance-based two-level design earthquake approach, Functional Evaluation Earthquake and Safety Evaluation Earthquake, has been adopted. The longitudinal tunnel and ground response seismic analyses are performed using a three-dimensional quasi-static linear elastic and nonlinear elastic discrete beam-spring elements to represent segmental liner and ground spring, respectively. Three components (longitudinal, transverse and vertical) of free-field ground displacement-time histories evaluated from site response analyses considering wave passage effects have been applied at the end support of the strain-compatible ground springs. The result of the longitudinal seismic analyses suggests that seismic joint for the mitigation measure requiring the design deflection capacity of 5-7.5 cm is to be furnished at the transition zone between hard and soft ground condition where the maximum member forces on the segmental liner (i.e., axial, shear forces and bending moments) are induced. The paper illustrates how detailed numerical analyses can be practically applied to evaluate the axial and curvature deformations along the tunnel alignment under difficult ground conditions and to provide the seismic joints at proper locations to effectively reduce the seismic demands below the allowable levels.

  17. Observation of rotational component in digital data of mining induced seismic events

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Knejzlík, Jaromír; Lednická, Markéta

    2012-01-01

    Roč. 7, č. 1 (2012), s. 75-85 ISSN 1896-3145. [Ochrona środowiska w górnictwie podziemnym, odkrywkowym i otworowym. Wieliczka - Zakrzow, 16.05.2012-18.05.2012] Institutional research plan: CEZ:AV0Z30860518 Keywords : rotational component * mining induced seismic event * field measurement Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  18. Detection, Location and Discrimination of Seismic Events by the Seismic Network of Israel,

    Science.gov (United States)

    1995-08-14

    Seismology Division, The Institute for Petroleum Research and Geophysics, Holon , Israel. Contract No. F19628-95-K-0006 Sponsored by DOE ABSTRACT The Israeli...Since 1984, data acquisition has been based on computerized systems . At present, the ISN consists of 36 short period stations distributed throughout...in Holon . There, the data are digitized (50 samples per second) and checked for event detection. Triggered events are routinely analyzed, yielding a

  19. Source mechanisms of mining-related seismic events in the Far West Rand, South Africa

    CSIR Research Space (South Africa)

    Kassa, BB

    2009-09-01

    Full Text Available Meeting and Exhibition Swaziland, 16 - 18 September 2009, pages 69 - 72 Source mechanisms of mining-related seismic events in the Far West Rand, South Africa BB Kassa1, J Julià2, AA Nyblade2 and RJ Durrheim1,3 1University of the Witwatersrand...). Geophysical Data Analysis: Discrete Inverse Theory, Academic Press, Orlando, Florida, 260 pp. Nyblade A.A., Walter, W.R., Gok, R., Linzer, L. and Durrheim, R.J. (2007). Developing and exploiting a unique seismic data set from South African gold mines...

  20. Role of the masonry in paintings during a seismic event analyzed by infrared vision

    Science.gov (United States)

    López, F.; Sfarra, S.; Ibarra-Castanedo, C.; Ambrosini, D.; Maldague, X. P. V.

    2015-06-01

    In this work, pulsed phase thermography (PPT), principal component thermography (PCT), and partial least squares thermography (PLST) techniques were applied in order to detect the masonry texture, as well as to map the subsurface damages formed beneath three different mural paintings. The latter were inspected after the 2009 earthquake, i.e., the seismic event that devastated L'Aquila City (Italy) and its surroundings. The mural supports explored by infrared thermography (IRT) are constituted by a single leaf, and the sides of the inspected paintings are confined by marble frames or by buried horizontal and vertical structures. Hence, the analyzed objects can be considered as monolithic structures. IRT can help to understand the masonry morphology, e.g. if there exist structural continuity between the arriccio layer (the first coat of plaster) and the support. In the present case, the heating phase was provided by lamps or propane gas and feature detection was enhanced by advanced signal processing. A comparison among the results is presented. Two of the three objects analyzed, painted by the art masters Serbucci and Avicola, are preserved inside Santa Maria della Croce di Roio Church in Roio Poggio (L'Aquila, Italy); they were executed on two masonries built in different periods. The last one was realized in Montorio al Vomano (Teramo, Italy) on the internal cloister of the Zoccolanti's Church (undated). The villages are separated by 50 km as the crow flies. Finally, near-infrared reflectography (NIRR) technique was also used to investigate the condition of the painting layer.

  1. The whole story: rumours and science communication in the aftermath of seismic events

    Science.gov (United States)

    Crescimbene, Massimo; Todesco, Micol; Camassi, Romano

    2016-04-01

    Controversies that stir the public debate on geological matters in Italy often pertain to two specific aspects: the actual trigger of geological phenomena (i.e., natural vs anthropogenic) and the trustworthiness of the experts who provide information and advise on the phenomena. A typical example of such difficulties is the case of the 2012 Emilia seismic sequence, which struck an area of moderate seismic hazard. At the same time, geophysical prospecting was planned to assess the potential of a reservoir for gas storage, near the town of Rivara. The low frequency of important seismic events in the area, associated with the ongoing industrial planning prompted widespread rumours of an anthropogenic origin of the 2012 earthquake. Since then, public concern has been risen several time by the occurrence of anomalous surface phenomena (among which heating of well water). While these phenomena always occurred in the area, and were recently explained in terms of a shallow, exothermic oxidation of methane, popular belief tends to establish a causal link between anomalous temperature and seismic activity. The ambiguity in the definition of the size of seismic events may further hinder communication efforts: such size may be expressed in different ways, and may assume different values depending on the adopted computational technique and on the size and geometry of the available seismic network. As a result, different institutions may release different numbers to express the magnitude of the same earthquake, casting doubts on the reliability of the estimate. We'll present and discuss different activities that INGV (Sezione di Bologna) pursued through the years, in collaboration with various local and national institutions, to provide an effective dissemination of scientific information and to reinforce mutual trust between our research institute and the local population.

  2. Detecting Events Beyond the Catalog - Applying Empirical Matched Field Processing to Salton Sea Geothermal Field Seismicity

    Science.gov (United States)

    Templeton, D. C.; Wang, J.; Harris, D. B.

    2011-12-01

    We apply the empirical Matched Field Processing (MFP) method to continuous seismic data obtained from the Salton Sea Geothermal Field to detect and locate more micorearthquakes than can be detected using only traditional earthquake detections methods. The empirical MFP method compares the amplitude and phase of the incoming seismic data to a set of pre-computed master templates. The master templates are created from previously observed earthquakes with good signal-to-noise ratio. We will relocate the seismicity using two different methods: hypoDD and BayesLoc. hypoDD is a double-difference earthquake relocation method that utilizes absolute P- and S-wave travel-time measurements and cross-correlation P- and S- wave differential travel-time measurements to determine high-resolution relative hypocenter locations (Waldhouser and Ellsworth, 2000). BayesLoc is a probabilistic (Bayesian) multiple-event locator that simultaneously provides a probabilistic characterization of the unknown origin parameters, corrections to the assumed travel-time model, improvements in the precision of the observed arrival-time data and accuracy of the assigned phase labels (Myers et al., 2007, 2009). Additionally, we will model the Coulomb stress changes, assuming the seismicity is due to an opening or shearing crack. We will match the location of the modeled stress increases with the locations of the mapped seismicity using a grid-search method.

  3. Study of seismic events in the Central Part of East European Platform

    Science.gov (United States)

    Gorbunova, Ella; Sanina, Irina; Ivanchenko, Galina; Nesterkina, Margarita; Konstantinovskaya, Natalya

    2015-04-01

    A measurement system for location seismic events in the Central Part of East European Platform is situated within the Mikhnevo Geophysical Observatory of the RAS Institute of Geospheres Dynamics and consists of 12 seismic stations. One vertical station is located in the center of the group in a shaft tunnel. The other stations are located on the periphery in three concentric circles and are almost equally spaced with regard to the terrain to ensure full azimuth coverage to the maximum extent possible. The unique array identifies events with a magnitude up to 3 at the distances until 1000 km within the Central Part of East European platform. Most of the events recorded by the Mikhnevo array at a distance of 60-500 km are man-made events represented by explosions in quarries during the development of mineral deposits. Long-term seismic records of explosions in quarries have been processed for the period from 2004 to 2014 to generate a database containing standard waveforms for each quarry. Some events of unknown origin appear in the records for this period; these do not correspond to the identified seismic forms for explosions in known quarries. Epicenter coordinates for these events do not match the coordinates of the known quarries. A cosmotectonic map of the Central Part of East European Platform was compiled during the studies using the LESSA software package (Lineament Extraction and Stripe Statistical Analysis) and data on the deep crustal structure, which made it possible to define the morphostructural plan and evaluate the geodynamic conditions in the area. The deep basement structure through the sedimentary cover is expressed in the surface texture of the area under study. The region's neotectonics is closely related to the history of deep structures, in particular, aulacogens extending in different directions, which may show in the contemporary morphostructural plan, mainly as inversion and partially inherited forms. Out of events of unknown nature

  4. 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

  5. Seismic survey in southeastern Socorro Island: Background noise measurements, seismic events, and T phases

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Raul W [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Galindo, Marta [Comprehensive Nuclear-Test-Ban Treaty Organization, IMS, Vienna (Austria); Pacheco, Javier F; Iglesias, Arturo; Teran, Luis F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Barreda, Jose L; Coba, Carlos [Facultad de Ingenieria, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

    2005-01-15

    We carried out a seismic survey and installed five portable, broadband seismometers in the southeastern corner of Socorro Island during June 1999. Power spectral densities for all five sites were relatively noisy when compared to reference curves around the world. Power spectral densities remain constant regardless of the time of day, or the day of the week. Cultural noise at the island is very small. Quiet and noisy sites were identified to determine the best location of the T phase station to be installed jointly by the Universidad Nacional Autonoma de Mexico and the Comprehensive Nuclear-Test-Ban Treaty Organization. During the survey six earthquakes were recorded at epicentral distances between 42 km and 2202 km, with magnitudes between 2.8 and 7.0. Two small earthquakes (M{sub c} = 2.8 and 3.3) occurred on the Clarion Fracture Zone. The four largest and more distant earthquakes produced T waves. One T wave from an epicenter near the coast of Guatemala had a duration of about 100 s and a frequency content between 2 and 8 Hz, with maximum amplitude at about 4.75 Hz. The Tehuacan earthquake of June 15, 1999 (M{sub w} = 7.0) produced arrivals of P {yields} T and S {yields} T waves, with energy between 2 Hz and 3.75 Hz. The earthquake occurred inland within the subducted Cocos plate at a depth of 60 km; a significant portion of the path was continental. Seismic P and S waves probably propagated upward in the subducted slab, and were converted to acoustic energy at the continental slope. Total duration of the T phase is close to 500 s and reaches its maximum amplitude about 200 s after the P {yields} T arrival. The T wave contains energy at frequencies between 2 and 10 Hz and reaches its maximum amplitude at about 2.5 Hz. T phases were also recorded from two earthquakes in Guerrero, Mexico and in the Rivera Fracture Zone. [Spanish] En junio de 1999 instalamos cinco sismometros portatiles de banda ancha en el sureste de la Isla Socorro. Se encontro que las densidades

  6. 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

  7. Measuring Single Event Upsets in the ATLAS Inner Tracker

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    When the HL-LHC starts collecting data, the electronics inside will be subject to massive amounts of radiation. As a result, single event upsets could pose a threat to the ATLAS readout chain. The ABC130, a prototype front-end ASIC for the ATLAS inner tracker, must be tested for its susceptibility to single event upsets.

  8. Seismic detection. Part II. Nuclear events. Volume III. 1975 (a bibliography with abstracts). Report for 1975--Feb 1976

    International Nuclear Information System (INIS)

    Habercom, G.E. Jr.

    1976-03-01

    Methods of seismic detection of nuclear events are investigated in the Government sponsored research reports. (This updated bibliography contains 145 abstracts, all of which are new entries to the previous edition.) For general seismic detection, see Part 1, NTIS/PS-76/0206

  9. Seismic detection. Part II. Nuclear events. Volume II. 1973--1974 (a bibliography with abstracts). Report for 1973--74

    International Nuclear Information System (INIS)

    Habercom, G.E. Jr.

    1976-03-01

    Methods of seismic detection of nuclear events are investigated in these Government-sponsored research reports. (This updated bibliography contains 124 abstracts, none of which are new entries to the previous edition.) For general seismic detection, see Part 1, NTIS/PS-76/0206

  10. Wilber 3: A Python-Django Web Application For Acquiring Large-scale Event-oriented Seismic Data

    Science.gov (United States)

    Newman, R. L.; Clark, A.; Trabant, C. M.; Karstens, R.; Hutko, A. R.; Casey, R. E.; Ahern, T. K.

    2013-12-01

    Since 2001, the IRIS Data Management Center (DMC) WILBER II system has provided a convenient web-based interface for locating seismic data related to a particular event, and requesting a subset of that data for download. Since its launch, both the scale of available data and the technology of web-based applications have developed significantly. Wilber 3 is a ground-up redesign that leverages a number of public and open-source projects to provide an event-oriented data request interface with a high level of interactivity and scalability for multiple data types. Wilber 3 uses the IRIS/Federation of Digital Seismic Networks (FDSN) web services for event data, metadata, and time-series data. Combining a carefully optimized Google Map with the highly scalable SlickGrid data API, the Wilber 3 client-side interface can load tens of thousands of events or networks/stations in a single request, and provide instantly responsive browsing, sorting, and filtering of event and meta data in the web browser, without further reliance on the data service. The server-side of Wilber 3 is a Python-Django application, one of over a dozen developed in the last year at IRIS, whose common framework, components, and administrative overhead represent a massive savings in developer resources. Requests for assembled datasets, which may include thousands of data channels and gigabytes of data, are queued and executed using the Celery distributed Python task scheduler, giving Wilber 3 the ability to operate in parallel across a large number of nodes.

  11. Peculiarity of the temporal distributions of seismic events in the Central America and Mexico.

    Science.gov (United States)

    Sasorova, E.; Levin, B.

    2010-03-01

    At first the interannual earthquake distributions and its peculiarity in predetermined region are considered. The hypothesis about within-year variability existence for the events of various energy levels was tested. The worldwide catalogs ISC (International Seismic Catalog) and NEIC (USGS) were used. It was extracted all EQs for the Pacific part of the given region from 1964 with Mb>=4.0. The entire set of events under analysis was divided into several magnitude ranges (MR). The analysis of the completeness of events in defined MRs was carried out. The aftershocks were canceled from the list. Further analysis was performed separately for each MR. Then the events in each magnitude level were subdivided once again into two groups: shallow events (H Htr), where Htr is depth threshold value. Then we are checking if the distributions of the events during the year period are uniform or these distributions are no uniform. We are testing our data separately for each magnitude level and for every depth level. The null hypothesis about uniform EQ distributions in the course of year was disproved for the most samples with shallow EQ (95%). But the null hypothesis was confirmed for deep earthquakes. We use the Chi-Square test for well-filled sequences and method of statistical testing for poor-filled sequences. The Htr value determines the boundary, which divided the seismic events in two groups. If the EQ's sources located above this boundary then such EQ's are distributed non-uniformly in the course of year. While if the EQ sources located below this boundary then distribution of such EQ during the year period are uniform. It was found by using special software procedure that the Htr boundary between the shallow and the deep events in the most cases was arranged in deep 60-80 km. The noticeable increase number of seismic events in short time intervals as a rule two times in year, and significant reducing of seismic activity in the rest part of the year was shown. It was

  12. Single Event Effect Hardware Trojans with Remote Activation

    Science.gov (United States)

    2017-03-01

    Interrupt SEFI Corruption of a data path leading to loss of normal operation Complex devices with built-in cpu/state machine or control...Acronym Description Devices Affected Single Event Upset SEU Corruption of the information stored in a memory element Memories, latches in logic...devices Multiple Bit Upset MBU Several memory elements corrupted by a single strike Memories, latches in logic devices Single Event Functional

  13. Feature selection of seismic waveforms for long period event detection at Cotopaxi Volcano

    Science.gov (United States)

    Lara-Cueva, R. A.; Benítez, D. S.; Carrera, E. V.; Ruiz, M.; Rojo-Álvarez, J. L.

    2016-04-01

    Volcano Early Warning Systems (VEWS) have become a research topic in order to preserve human lives and material losses. In this setting, event detection criteria based on classification using machine learning techniques have proven useful, and a number of systems have been proposed in the literature. However, to the best of our knowledge, no comprehensive and principled study has been conducted to compare the influence of the many different sets of possible features that have been used as input spaces in previous works. We present an automatic recognition system of volcano seismicity, by considering feature extraction, event classification, and subsequent event detection, in order to reduce the processing time as a first step towards a high reliability automatic detection system in real-time. We compiled and extracted a comprehensive set of temporal, moving average, spectral, and scale-domain features, for separating long period seismic events from background noise. We benchmarked two usual kinds of feature selection techniques, namely, filter (mutual information and statistical dependence) and embedded (cross-validation and pruning), each of them by using suitable and appropriate classification algorithms such as k Nearest Neighbors (k-NN) and Decision Trees (DT). We applied this approach to the seismicity presented at Cotopaxi Volcano in Ecuador during 2009 and 2010. The best results were obtained by using a 15 s segmentation window, feature matrix in the frequency domain, and DT classifier, yielding 99% of detection accuracy and sensitivity. Selected features and their interpretation were consistent among different input spaces, in simple terms of amplitude and spectral content. Our study provides the framework for an event detection system with high accuracy and reduced computational requirements.

  14. Stress Drop Estimates from Induced Seismic Events in the Fort Worth Basin, Texas

    Science.gov (United States)

    Jeong, S. J.; Stump, B. W.; DeShon, H. R.

    2017-12-01

    Since the beginning of Barnett shale oil and gas production in the Fort Worth Basin, there have been earthquake sequences, including multiple magnitude 3.0+ events near the DFW International Airport, Azle, Irving-Dallas, and throughout Johnson County (Cleburne and Venus). These shallow depth earthquakes (2 to 8 km) have not exceeded magnitude 4.0 and have been widely felt; the close proximity of these earthquakes to a large population center motivates an assessment of the kinematics of the events in order to provide more accurate ground motion predictions. Previous studies have estimated average stress drops for the DFW airport and Cleburne earthquakes at 10 and 43 bars, respectively. Here, we calculate stress drops for Azle, Irving-Dallas and Venus earthquakes using seismic data from local (≤25 km) and regional (>25 km) seismic networks. Events with magnitudes above 2.5 are chosen to ensure adequate signal-to-noise. Stress drops are estimated by fitting the Brune earthquake model to the observed source spectrum with correction for propagation path effects and a local site effect using a high-frequency decay parameter, κ, estimated from acceleration spectrum. We find that regional average stress drops are similar to those estimated using local data, supporting the appropriateness of the propagation path and site corrections. The average stress drop estimates are 72 bars, which range from 7 to 240 bars. The results are consistent with global averages of 10 to 100 bars for intra-plate earthquakes and compatible with stress drops of DFW airport and Cleburne earthquakes. The stress drops show a slight breakdown in self-similarity with increasing moment magnitude. The breakdown of similarity for these events requires further study because of the limited magnitude range of the data. These results suggest that strong motions and seismic hazard from an injection-induced earthquake can be expected to be similar to those for tectonic events taking into account the shallow

  15. Analysis of Single Event Evoked Potentials.

    Science.gov (United States)

    1979-11-01

    stimuli is available in the literature, and since this study deals with single responses, an assumption had to be made before the information in the...Figue 4 Repon e mocekroadpten.trp atrsadt ln 0m10 4 4 22 A S10 2D 3 40 5 64 10 i 13 10 II0 Visul wo (miautes) of side of dck Figure 5. The effect of unit...differences in their average evoked responses. These responses will also lend themselves to detection based on information from multiple electrodes because

  16. Source process of very long period seismic events associated with the 1998 activity of Iwate Volcano, northeastern Japan

    Science.gov (United States)

    Nishimura, Takeshi; Nakamichi, Haruhisa; Tanaka, Satoru; Sato, Minemori; Kobayashi, Tomokatsu; Ueki, Sadato; Hamaguchi, Hiroyuki; Ohtake, Masakazu; Sato, Haruo

    2000-08-01

    We observed very long period seismic events that are associated with the 1998 activity of Iwate Volcano, northeast Japan. The events show a dominant period of 10 s and duration of 30-60 s, often with accompanying short-period waves at the beginning and at the end of the long-period signals. By analyzing the broadband seismograms we find that the source elongates in the east-west direction for ˜4 km at a depth of 2 km beneath the western part of Iwate Volcano. Results of moment tensor inversions show a source mechanism of mutual deflation and inflation of two chambers located at the western and eastern edges of the source region. The source region coincides with the low seismic velocity zone detected by seismic tomography and is very close to the locations of pressure sources estimated from crustal deformation data. On the basis of these results we infer that the very long period seismic events are generated by transportation and movement of magmatic fluid (hot water and/or magma) in a shallow part of the volcano. We further present a simple source model of very long period seismic events based on one-dimensional flow dynamics and propose a new parameter to characterize the size of very long period event: the energy flow rate, which is obtained by dividing the seismic moment by the dominant period. The energy flow rate was estimated as 3.1×1012 J/s for the event on July 29, 1998.

  17. Analysis of post-blasting source mechanisms of mining-induced seismic events in Rudna copper mine, Poland

    Directory of Open Access Journals (Sweden)

    Caputa Alicja

    2015-10-01

    Full Text Available The exploitation of georesources by underground mining can be responsible for seismic activity in areas considered aseismic. Since strong seismic events are connected with rockburst hazard, it is a continuous requirement to reduce seismic risk. One of the most effective methods to do so is blasting in potentially hazardous mining panels. In this way, small to moderate tremors are provoked and stress accumulation is substantially reduced. In this paper we present an analysis of post-blasting events using Full Moment Tensor (MT inversion at the Rudna mine, Poland, underground seismic network. In addition, we describe the problems we faced when analyzing seismic signals. Our studies show that focal mechanisms for events that occurred after blasts exhibit common features in the MT solution. The strong isotropic and small Double Couple (DC component of the MT, indicate that these events were provoked by detonations. On the other hand, post-blasting MT is considerably different than the MT obtained for strong mining events. We believe that seismological analysis of provoked and unprovoked events can be a very useful tool in confirming the effectiveness of blasting in seismic hazard reduction in mining areas.

  18. Discovering new events beyond the catalogue—application of empirical matched field processing to Salton Sea geothermal field seismicity

    Science.gov (United States)

    Wang, Jingbo; Templeton, Dennise C.; Harris, David B.

    2015-10-01

    Using empirical matched field processing (MFP), we compare 4 yr of continuous seismic data to a set of 195 master templates from within an active geothermal field and identify over 140 per cent more events than were identified using traditional detection and location techniques alone. In managed underground reservoirs, a substantial fraction of seismic events can be excluded from the official catalogue due to an inability to clearly identify seismic-phase onsets. Empirical MFP can improve the effectiveness of current seismic detection and location methodologies by using conventionally located events with higher signal-to-noise ratios as master events to define wavefield templates that could then be used to map normally discarded indistinct seismicity. Since MFP does not require picking, it can be carried out automatically and rapidly once suitable templates are defined. In this application, we extend MFP by constructing local-distance empirical master templates using Southern California Earthquake Data Center archived waveform data of events originating within the Salton Sea Geothermal Field. We compare the empirical templates to continuous seismic data collected between 1 January 2008 and 31 December 2011. The empirical MFP method successfully identifies 6249 additional events, while the original catalogue reported 4352 events. The majority of these new events are lower-magnitude events with magnitudes between M0.2-M0.8. The increased spatial-temporal resolution of the microseismicity map within the geothermal field illustrates how empirical MFP, when combined with conventional methods, can significantly improve seismic network detection capabilities, which can aid in long-term sustainability and monitoring of managed underground reservoirs.

  19. Future challenges in single event effects for advanced CMOS technologies

    International Nuclear Information System (INIS)

    Guo Hongxia; Wang Wei; Luo Yinhong; Zhao Wen; Guo Xiaoqiang; Zhang Keying

    2010-01-01

    SEE have became a substantial Achilles heel for the reliability of space-based advanced CMOS technologies with features size downscaling. Future space and defense systems require identification and understanding of single event effects to develop hardening approaches for advanced technologies, including changes in device geometry and materials affect energy deposition, charge collection,circuit upset, parametric degradation devices. Topics covered include the impact of technology scaling on radiation response, including single event transients in high speed digital circuits, evidence for single event effects caused by proton direct ionization, and the impact for SEU induced by particle energy effects and indirect ionization. The single event effects in CMOS replacement technologies are introduced briefly. (authors)

  20. Non Invasive Instrumentation For Single Event Effects (NIISEE), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — On this Phase 1 project, Adventium will identify and address key hurdles to achieve Radiation Hardening by Software (RHS) for Single Event Effects (SEEs) for modern...

  1. Variation of radon levels in spring water with meteorological parameters and seismic events in Garhwal Himalayas

    International Nuclear Information System (INIS)

    Prasad, Yogesh; Prasad, Ganesh; Negi, M.S.; Ramola, R.C.; Choubey, V.M.

    2006-01-01

    Radon is being measured continuously in spring water at Badshahi Thaul Campus, Tehri Garhwal in Himalayan region by using radon emanometer since December 2002. An effort was made to correlate the variance of radon concentration in spring water with meteorological parameters and seismic events in study area. The positive correlation (coefficient = 0.79, 0.53, 0.60 and 0.70) was observed between measured radon concentration and minimum and maximum temperature, relative humidity and water discharge rate from the spring, respectively. However, no correlation was recorded between radon concentration and rain fall in the study area. Sudden increase in radon concentration in spring water were observed before the earthquakes occurred on 24 January 2003 of magnitude 3.4 on Richter scale having epicenter near Uttarkashi in Garhwal Himalaya and on 31 January 2003 of magnitude 3.1 on Richter scale having epicenter almost in same area. Similar changes in radon concentration were recorded before the earthquakes occurred on 4 April 2003 with magnitude 4.0 having epicenter near Almora in Kumaon Himalaya and on 26 May 2003 having magnitude 3.5 in Chamoli region of Garhwal Himalaya. Regular radon anomaly was recorded with micro seismic events from 5th August to 4th September 2003, which is discussed in detail. The impact of non geophysical and geophysical events on radon concentration in spring water is discussed in details. This type of study will help us to develop earthquake alarm model from radon in near future. (author)

  2. Evaluation of Multi Canister Overpack (MCO) Handling Machine Uplift Restraint for a Seismic Event During Repositioning Operations

    International Nuclear Information System (INIS)

    SWENSON, C.E.

    2000-01-01

    Insertion of the Multi-Canister Overpack (MCO) assemblies into the Canister Storage Building (CSB) storage tubes involves the use of the MCO Handling Machine (MHM). During MCO storage tube insertion operations, inadvertent movement of the MHM is prevented by engaging seismic restraints (''active restraints'') located adjacent to both the bridge and trolley wheels. During MHM repositioning operations, the active restraints are not engaged. When the active seismic restraints are not engaged, the only functioning seismic restraints are non-engageable (''passive'') wheel uplift restraints which function only if the wheel uplift is sufficient to close the nominal 0.5-inch gap at the uplift restraint interface. The MHM was designed and analyzed in accordance with ASME NOG-1-1995. The ALSTHOM seismic analysis reported seismic loads on the MHM uplift restraints and EDERER performed corresponding structural calculations to demonstrate structural adequacy of the seismic uplift restraint hardware. The ALSTHOM and EDERER calculations were performed for a parked MHM with the active seismic restraints engaged, resulting in uplift restraint loading only in the vertical direction. In support of development of the CSB Safety Analysis Report (SAR), an evaluation of the MHM seismic response was requested for the case where the active seismic restraints are not engaged. If a seismic event occurs during MHM repositioning operations, a moving contact at a seismic uplift restraint would introduce a friction load on the restraint in the direction of the movement. These potential horizontal friction loads on the uplift restraints were not included in the existing restraint hardware design calculations. One of the purposes of the current evaluation is to address the structural adequacy of the MHM seismic uplift restraints with the addition of the horizontal friction associated with MHM repositioning movements

  3. Evaluation of Multi Canister Overpack (MCO) Handling Machine Uplift Restraint for a Seismic Event During Repositioning Operations

    Energy Technology Data Exchange (ETDEWEB)

    SWENSON, C.E.

    2000-05-15

    Insertion of the Multi-Canister Overpack (MCO) assemblies into the Canister Storage Building (CSB) storage tubes involves the use of the MCO Handling Machine (MHM). During MCO storage tube insertion operations, inadvertent movement of the MHM is prevented by engaging seismic restraints (''active restraints'') located adjacent to both the bridge and trolley wheels. During MHM repositioning operations, the active restraints are not engaged. When the active seismic restraints are not engaged, the only functioning seismic restraints are non-engageable (''passive'') wheel uplift restraints which function only if the wheel uplift is sufficient to close the nominal 0.5-inch gap at the uplift restraint interface. The MHM was designed and analyzed in accordance with ASME NOG-1-1995. The ALSTHOM seismic analysis reported seismic loads on the MHM uplift restraints and EDERER performed corresponding structural calculations to demonstrate structural adequacy of the seismic uplift restraint hardware. The ALSTHOM and EDERER calculations were performed for a parked MHM with the active seismic restraints engaged, resulting in uplift restraint loading only in the vertical direction. In support of development of the CSB Safety Analysis Report (SAR), an evaluation of the MHM seismic response was requested for the case where the active seismic restraints are not engaged. If a seismic event occurs during MHM repositioning operations, a moving contact at a seismic uplift restraint would introduce a friction load on the restraint in the direction of the movement. These potential horizontal friction loads on the uplift restraints were not included in the existing restraint hardware design calculations. One of the purposes of the current evaluation is to address the structural adequacy of the MHM seismic uplift restraints with the addition of the horizontal friction associated with MHM repositioning movements.

  4. Testing the Quick Seismic Event Locator and Magnitude Calculator (SSL_Calc) by Marsite Project Data Base

    Science.gov (United States)

    Tunc, Suleyman; Tunc, Berna; Caka, Deniz; Baris, Serif

    2016-04-01

    Locating and calculating size of the seismic events is quickly one of the most important and challenging issue in especially real time seismology. In this study, we developed a Matlab application to locate seismic events and calculate their magnitudes (Local Magnitude and empirical Moment Magnitude) using single station called SSL_Calc. This newly developed sSoftware has been tested on the all stations of the Marsite project "New Directions in Seismic Hazard Assessment through Focused Earth Observation in the Marmara Supersite-MARsite". SSL_Calc algorithm is suitable both for velocity and acceleration sensors. Data has to be in GCF (Güralp Compressed Format). Online or offline data can be selected in SCREAM software (belongs to Guralp Systems Limited) and transferred to SSL_Calc. To locate event P and S wave picks have to be marked by using SSL_Calc window manually. During magnitude calculation, instrument correction has been removed and converted to real displacement in millimeter. Then the displacement data is converted to Wood Anderson Seismometer output by using; Z=[0;0]; P=[-6.28+4.71j; -6.28-4.71j]; A0=[2080] parameters. For Local Magnitude calculation,; maximum displacement amplitude (A) and distance (dist) are used in formula (1) for distances up to 200km and formula (2) for more than 200km. ML=log10(A)-(-1.118-0.0647*dist+0.00071*dist2-3.39E-6*dist3+5.71e-9*dist4) (1) ML=log10(A)+(2.1173+0.0082*dist-0.0000059628*dist2) (2) Following Local Magnitude calculation, the programcode calculates two empiric Moment Magnitudes using formulas (3) Akkar et al. (2010) and (4) Ulusay et al. (2004). Mw=0.953* ML+0.422 (3) Mw=0.7768* ML+1.5921 (4) SSL_Calc is a software that is easy to implement and user friendly and offers practical solution to individual users to location of event and ML, Mw calculation.

  5. Nonlinear dynamic failure process of tunnel-fault system in response to strong seismic event

    Science.gov (United States)

    Yang, Zhihua; Lan, Hengxing; Zhang, Yongshuang; Gao, Xing; Li, Langping

    2013-03-01

    Strong earthquakes and faults have significant effect on the stability capability of underground tunnel structures. This study used a 3-Dimensional Discrete Element model and the real records of ground motion in the Wenchuan earthquake to investigate the dynamic response of tunnel-fault system. The typical tunnel-fault system was composed of one planned railway tunnel and one seismically active fault. The discrete numerical model was prudentially calibrated by means of the comparison between the field survey and numerical results of ground motion. It was then used to examine the detailed quantitative information on the dynamic response characteristics of tunnel-fault system, including stress distribution, strain, vibration velocity and tunnel failure process. The intensive tunnel-fault interaction during seismic loading induces the dramatic stress redistribution and stress concentration in the intersection of tunnel and fault. The tunnel-fault system behavior is characterized by the complicated nonlinear dynamic failure process in response to a real strong seismic event. It can be qualitatively divided into 5 main stages in terms of its stress, strain and rupturing behaviors: (1) strain localization, (2) rupture initiation, (3) rupture acceleration, (4) spontaneous rupture growth and (5) stabilization. This study provides the insight into the further stability estimation of underground tunnel structures under the combined effect of strong earthquakes and faults.

  6. 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

  7. Estimation of finite seismic source parameters for selected events of the West Bohemia year 2008 seismic swarm

    Czech Academy of Sciences Publication Activity Database

    Kolář, Petr; Růžek, Bohuslav

    2015-01-01

    Roč. 19, č. 2 (2015), s. 403-421 ISSN 1383-4649 R&D Projects: GA ČR GAP210/10/1728 Institutional support: RVO:67985530 Keywords : West Bohemia year 2008 seismic swarm * finite seismic source * stopping phases * stress drop Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.550, year: 2015

  8. Full waveform inversion of repeating seismic events to estimate time-lapse velocity changes

    Science.gov (United States)

    Kamei, R.; Lumley, D.

    2017-05-01

    Seismic monitoring provides valuable information regarding the time-varying changes in subsurface physical properties caused by natural or man-made processes. However, the resulting changes in the earth's subsurface properties are often small both in terms of magnitude and spatial extent, leading to minimal time-lapse differences in seismic amplitude or traveltime. In order to better extract information from the time-lapse data, we show that exploiting the full seismic waveform information can be critical. In this study, we develop and test methods of full waveform inversion that estimate an optimal subsurface model of time-varying elastic properties in order to fit the observed time-lapse seismic data with predicted waveforms based on numerical solutions of the wave equation. Time-lapse full waveform inversion is nonlinear and non-unique, and depends on the knowledge of the baseline velocity model before a change, and (non-)repeatability of earthquake source and sensor parameters, and of ambient and cultural noise. We propose to use repeating earthquake data sets acquired with permanent arrays of seismic sensors to enhance the repeatability of source and sensor parameters. We further develop and test time-lapse parallel, double-difference and bootstrapping inversion strategies to mitigate the dependence on the baseline velocity model. The parallel approach uses a time-invariant full waveform inversion method to estimate velocity models independently of the different source event times. The double-difference approach directly estimates velocity changes from time-lapse waveform differences, requiring excellent repeatability. The bootstrapping approach inverts for velocity models sequentially in time, implicitly constraining the time-lapse inversions, while relaxing an explicit requirement for high data repeatability. We assume that prior to the time-lapse inversion, we can estimate the true source locations and the origin time of the events, and also we can also

  9. Ground truth seismic events and location capability at Degelen mountain, Kazakhstan

    Science.gov (United States)

    Trabant, C.; Thurber, C.; Leith, W.

    2002-01-01

    We utilized nuclear explosions from the Degelen Mountain sub-region of the Semipalatinsk Test Site (STS), Kazakhstan, to assess seismic location capability directly. Excellent ground truth information for these events was either known or was estimated from maps of the Degelen Mountain adit complex. Origin times were refined for events for which absolute origin time information was unknown using catalog arrival times, our ground truth location estimates, and a time baseline provided by fixing known origin times during a joint hypocenter determination (JHD). Precise arrival time picks were determined using a waveform cross-correlation process applied to the available digital data. These data were used in a JHD analysis. We found that very accurate locations were possible when high precision, waveform cross-correlation arrival times were combined with JHD. Relocation with our full digital data set resulted in a mean mislocation of 2 km and a mean 95% confidence ellipse (CE) area of 6.6 km2 (90% CE: 5.1 km2), however, only 5 of the 18 computed error ellipses actually covered the associated ground truth location estimate. To test a more realistic nuclear test monitoring scenario, we applied our JHD analysis to a set of seven events (one fixed) using data only from seismic stations within 40?? epicentral distance. Relocation with these data resulted in a mean mislocation of 7.4 km, with four of the 95% error ellipses covering less than 570 km2 (90% CE: 438 km2), and the other two covering 1730 and 8869 km2 (90% CE: 1331 and 6822 km2). Location uncertainties calculated using JHD often underestimated the true error, but a circular region with a radius equal to the mislocation covered less than 1000 km2 for all events having more than three observations. ?? 2002 Elsevier Science B.V. All rights reserved.

  10. Near bed suspended sediment flux by single turbulent events

    Science.gov (United States)

    Amirshahi, Seyed Mohammad; Kwoll, Eva; Winter, Christian

    2018-01-01

    The role of small scale single turbulent events in the vertical mixing of near bed suspended sediments was explored in a shallow shelf sea environment. High frequency velocity and suspended sediment concentration (SSC; calibrated from the backscatter intensity) were collected using an Acoustic Doppler Velocimeter (ADV). Using quadrant analysis, the despiked velocity time series was divided into turbulent events and small background fluctuations. Reynolds stress and Turbulent Kinetic Energy (TKE) calculated from all velocity samples, were compared to the same turbulent statistics calculated only from velocity samples classified as turbulent events (Reevents and TKEevents). The comparison showed that Reevents and TKEevents was increased 3 and 1.6 times, respectively, when small background fluctuations were removed and that the correlation with SSC for TKE could be improved through removal of the latter. The correlation between instantaneous vertical turbulent flux (w ‧) and SSC fluctuations (SSC ‧) exhibits a tidal pattern with the maximum correlation at peak ebb and flood currents, when strong turbulent events appear. Individual turbulent events were characterized by type, strength, duration and length. Cumulative vertical turbulent sediment fluxes and average SSC associated with individual turbulent events were calculated. Over the tidal cycle, ejections and sweeps were the most dominant events, transporting 50% and 36% of the cumulative vertical turbulent event sediment flux, respectively. Although the contribution of outward interactions to the vertical turbulent event sediment flux was low (11%), single outward interaction events were capable of inducing similar SSC ‧ as sweep events. The results suggest that on time scales of tens of minutes to hours, TKE may be appropriate to quantify turbulence in sediment transport studies, but that event characteristics, particular the upward turbulent flux need to be accounted for when considering sediment transport

  11. European accelerator facilities for single event effects testing

    Energy Technology Data Exchange (ETDEWEB)

    Adams, L.; Nickson, R.; Harboe-Sorensen, R. [ESA-ESTEC, Noordwijk (Netherlands); Hajdas, W.; Berger, G.

    1997-03-01

    Single event effects are an important hazard to spacecraft and payloads. The advances in component technology, with shrinking dimensions and increasing complexity will give even more importance to single event effects in the future. The ground test facilities are complex and expensive and the complexities of installing a facility are compounded by the requirement that maximum control is to be exercised by users largely unfamiliar with accelerator technology. The PIF and the HIF are the result of experience gained in the field of single event effects testing and represent a unique collaboration between space technology and accelerator experts. Both facilities form an essential part of the European infrastructure supporting space projects. (J.P.N.)

  12. AP1000{sup R} design robustness against extreme external events - Seismic, flooding, and aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)

    2012-07-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel

  13. AP1000R design robustness against extreme external events - Seismic, flooding, and aircraft crash

    International Nuclear Information System (INIS)

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J.

    2012-01-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000 R nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel which is

  14. Seismic constraints on a large dyking event and initiation of a transform fault zone in Western Gulf of Aden

    Science.gov (United States)

    Ahmed, AbdulHakim; Doubre, Cecile; Leroy, Sylvie; Perrot, Julie; Audin, Laurence; Rolandone, Frederique; Keir, Derek; Al-Ganad, Ismael; Sholan, Jamal; Khanbari, Khaled; Mohamed, Kassim; Vergne, Jerome; Jacques, Eric; Nercessian, Alex

    2013-04-01

    In November 2010, a large number of events were recorded by the world seismic networks showing important activity occurring along the western part of the Aden Ridge. West of the Shulka El Sheik fracture zone, events in this large seismic swarm (magnitudes above 5) occurred in a complex area, where the change of both the ridge direction and the bathymetry suggest the propagation of the ridge into a continental lithosphere and the influence of the Afar plume. We combine several sets of data from permanent networks and temporary 3C broad stations installed after the beginning of the event along the southern and eastern coasts of Yemen and Djibouti respectively, we located more than 600 earthquakes with magnitudes ranging from 2.5 to 5.6 that occurred during the first months following the first event. The spatial distribution of the main seismicity reveals a very clear N115° -trending alignment, parallel to the mean direction of the en-echelon spreading segments that form the ridge at this longitude. Half of the events, which represent half of the total seismic energy released during the first months, are located in the central third section of the segment. Here several volcanic cones and recent lava flows observed from bathymetric and acoustic reflectivity data during the Tadjouraden cruise (Audin, 1999, Dauteuil et al., 2001) constitute the sea floor. In addition to this main activity, two small groups of events suggest the activiation of landslides into a large fan and the activity in a volcanic area 50 km due east from the main active zone. The time evolution of the seismicity shows several bursts of activity. Some of them are clearly related to sudden activities within the volcanic areas, when others exhibit horizontal migration of the events, with velocity around ˜ 1 km/h. The time-space evolution of the seismicity clearly reveals the intrusion of dykes associated with magma propagation from the crustal magmatic centres into the rift zone. Taking into account

  15. Multi-Unit Initiating Event Analysis for a Single-Unit Internal Events Level 1 PSA

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong San; Park, Jin Hee; Lim, Ho Gon [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The Fukushima nuclear accident in 2011 highlighted the importance of considering the risks from multi-unit accidents at a site. The ASME/ANS probabilistic risk assessment (PRA) standard also includes some requirements related to multi-unit aspects, one of which (IE-B5) is as follows: 'For multi-unit sites with shared systems, DO NOT SUBSUME multi-unit initiating events if they impact mitigation capability [1].' However, the existing single-unit PSA models do not explicitly consider multi-unit initiating events and hence systems shared by multiple units (e.g., alternate AC diesel generator) are fully credited for the single unit and ignores the need for the shared systems by other units at the same site [2]. This paper describes the results of the multi-unit initiating event (IE) analysis performed as a part of the at-power internal events Level 1 probabilistic safety assessment (PSA) for an OPR1000 single unit ('reference unit'). In this study, a multi-unit initiating event analysis for a single-unit PSA was performed, and using the results, dual-unit LOOP initiating event was added to the existing PSA model for the reference unit (OPR1000 type). Event trees were developed for dual-unit LOOP and dual-unit SBO which can be transferred from dual- unit LOOP. Moreover, CCF basic events for 5 diesel generators were modelled. In case of simultaneous SBO occurrences in both units, this study compared two different assumptions on the availability of the AAC D/G. As a result, when dual-unit LOOP initiating event was added to the existing single-unit PSA model, the total CDF increased by 1∼ 2% depending on the probability that the AAC D/G is available to a specific unit in case of simultaneous SBO in both units.

  16. Analysis of the behaviour of the CLIC_SiD iron return yoke during a seismic event

    CERN Document Server

    Duarte Ramos, F.

    2012-01-01

    The iron return yoke of the CLIC SiD detector concept is composed of three barrel rings and two endcap discs which, during a seismic event, are subjected to horizontal and vertical accelerations that can result in both a mechanical failure of internal structural elements and high deformations which can lead to unwanted collisions with other internal or external detector elements, as well as the walls of the experimental cavern. This report presents the results from the analysis of the return yoke barrel rings and endcaps under a seismic event load case.

  17. Central Italy magnetotelluric investigation. Structures and relations to seismic events: analysis of initial data

    Directory of Open Access Journals (Sweden)

    J. Marianiuk

    1996-06-01

    Full Text Available A scientific collaboration between the Warsaw Academy of Science, (Poland and the National Institute of Geophysics (Italy, gave rise to the installation of few stations for the long term measurement of magnetotelluric fields in central Italy. The selection of investigation sites was determined by the individual seismic interest of each location. The project began in the summer of 1991, with the installation of 2 magnetotelluric stations in the province of Isernia, (Collemeluccio and Montedimezzo. In 1992, 2 more stations became operative, one in the province of Rieti, (Fassinoro, the other in the province of L'Aquila, (S. Vittoria. For the purpose of this project, the magnetic observatory in L'Aquila was also equipped with electric lines, for the measurement of the telluric field. The aim of the analysis here presented, is to show that is possible to follow the temporal evolution of magnetotelluric characteristic parameters. At Collemeluccio this evolution was compared with the seismic released energy for events recorded within the study area.

  18. Characteristics of aperiodic sequence of slip events caused by interaction between seismic patches and that caused be self-organized stress heterogeneity

    Science.gov (United States)

    Kato, N.

    2017-12-01

    Numerical simulations of earthquake cycles are conducted to investigate the origin of complexity of earthquake recurrence. There are two main causes of the complexity. One is self-organized stress heterogeneity due to dynamical effect. The other is the effect of interaction between some fault patches. In the model, friction on the fault is assumed to obey a rate- and state-dependent friction law. Circular patches of velocity-weakening frictional property are assumed on the fault. On the remaining areas of the fault, velocity-strengthening friction is assumed. We consider three models: Single patch model, two-patch model, and three-patch model. In the first model, the dynamical effect is mainly examined. The latter two models take into consideration the effect of interaction as well as the dynamical effect. Complex multiperiodic or aperiodic sequences of slip events occur when slip behavior changes from the seismic to aseismic, and when the degree of interaction between seismic patches is intermediate. The former is observed in all the models, and the latter is observed in the two-patch model and the three-patch model. Evolution of spatial distribution of shear stress on the fault suggests that aperiodicity at the transition from seismic to aseismic slip is caused by self-organized stress heterogeneity. The iteration maps of recurrence intervals of slip events in aperiodic sequences are examined, and they are approximately expressed by simple curves for aperiodicity at the transition from seismic to aseismic slip. In contrast, the iteration maps for aperiodic sequences caused by interaction between seismic patches are scattered and they are not expressed by simple curves. This result suggests that complex sequences caused by different mechanisms may be distinguished.

  19. Planning Single-Event Nutrition Education: A New Model

    Science.gov (United States)

    Brown, Lora Beth

    2011-01-01

    A theoretical model for planning single-event nutrition education contrasts a Practical, Foods, and Positive (PFP) emphasis to an Abstract, Nutrient, and Negative (ANN) focus on nutrition topics. Use of this model makes messages more appealing to consumers and may increase the likelihood that people will apply the nutrition information in their…

  20. Physical mechanisms of single-event effects in advanced microelectronics

    International Nuclear Information System (INIS)

    Schrimpf, Ronald D.; Weller, Robert A.; Mendenhall, Marcus H.; Reed, Robert A.; Massengill, Lloyd W.

    2007-01-01

    The single-event error rate in advanced semiconductor technologies can be estimated more accurately than conventional methods by using simulation based on accurate descriptions of a large number of individual particle interactions. The results can be used to select the ion types and energies for accelerator testing and to identify situations in which nuclear reactions will contribute to the error rate

  1. Single Event Effects in FPGA Devices 2015-2016

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth; Pellish, Jonathan

    2016-01-01

    This presentation provides an overview of single event effects in FPGA devices 2015-2016 including commercial Xilinx V5 heavy ion accelerated testing, Xilinx Kintex-7 heavy ion accelerated testing, mitigation study, and investigation of various types of triple modular redundancy (TMR) for commercial SRAM based FPGAs.

  2. Spatial correlation for horizontal and vertical components of acceleration from northern Iran seismic events

    Science.gov (United States)

    Garakaninezhad, Alireza; Bastami, Morteza; Soghrat, Mohammad Reza

    2017-11-01

    The evaluation of seismic risk of spatially distributed systems requires the spatial correlation model for ground motion intensity measures. This study investigates the spatial correlation of four earthquakes recorded in northern Iran. The intra-event spatial correlation for both horizontal and vertical components of spectral acceleration at eight periods in the range of 0.0-3.0 s is estimated using geostatistical tools. An exponential form is chosen to fit experimental semivariograms, and the correlation ranges of spectral accelerations as a function of period are derived. The results show similar trend of correlation ranges for both components. It should be mentioned that the ranges for the vertical component, in general, are higher than those observed for the horizontal one. For both components, the correlation ranges as a function of period are divided into three segments. The first and the third one are increasing while the second one is decreasing with increasing period.

  3. Automatic seismic event detection using migration and stacking: a performance and parameter study in Hengill, southwest Iceland

    Science.gov (United States)

    Wagner, F.; Tryggvason, A.; Roberts, R.; Lund, B.; Gudmundsson, Ó.

    2017-06-01

    We investigate the performance of a seismic event detection algorithm using migration and stacking of seismic traces. The focus lies on determining optimal data dependent detection parameters for a data set from a temporary network in the volcanically active Hengill area, southwest Iceland. We test variations of the short-term average to long-term average and Kurtosis functions, calculated from filtered seismic traces, as input data. With optimal detection parameters, our algorithm identified 94 per cent (219 events) of the events detected by the South Iceland Lowlands (SIL) system, that is, the automatic system routinely used on Iceland, as well as a further 209 events, previously missed. The assessed number of incorrect (false) detections was 25 per cent for our algorithm, which was considerably better than that from SIL (40 per cent). Empirical tests show that well-functioning processing parameters can be effectively selected based on analysis of small, representative subsections of data. Our migration approach is more computationally expensive than some alternatives, but not prohibitively so, and it appears well suited to analysis of large swarms of low magnitude events with interevent times on the order of seconds. It is, therefore, an attractive, practical tool for monitoring of natural or anthropogenic seismicity related to, for example, volcanoes, drilling or fluid injection.

  4. Seismic source mechanism inversion from a linear array of receivers reveals non-double-couple seismic events induced by hydraulic fracturing in sedimentary formation

    Czech Academy of Sciences Publication Activity Database

    Jechumtálová, Zuzana; Eisner, L.

    2008-01-01

    Roč. 460, č. 1-4 (2008), s. 124-133 ISSN 0040-1951 R&D Projects: GA AV ČR KJB300120504; GA AV ČR IAA300120502 Grant - others:EC(XE) MTKI-CT-2004-517242 Institutional research plan: CEZ:AV0Z30120515 Keywords : source mechanism * seismic events * hydraulic fracturing Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.677, year: 2008

  5. Seismic detection of meteorite impacts on Mars

    OpenAIRE

    Teanby , N.A.; Wookey , J.

    2011-01-01

    Abstract Meteorite impacts provide a potentially important seismic source for probing Mars? interior. It has recently been shown that new craters can be detected from orbit using high resolution imaging, which means the location of any impact-related seismic event could be accurately determined thus improving the constraints that could be placed on internal structure using a single seismic station. This is not true of other seismic sources on Mars such as sub-surface faulting, whic...

  6. Do multiple health events reduce resilience when compared with single events?

    Science.gov (United States)

    Morin, Ruth T; Galatzer-Levy, Isaac R; Maccallum, Fiona; Bonanno, George A

    2017-08-01

    The impact of multiple major life stressors is hypothesized to reduce the probability of resilience and increase rates of mortality. However, this hypothesis lacks strong empirical support because of the lack of prospective evidence. This study investigated whether experiencing multiple major health events diminishes rates of resilience and increases rates of mortality using a large population-based prospective cohort. There were n = 1,395 individuals sampled from the Health and Retirement Study (HRS) and examined prospectively from 2 years before 4 years after either single or multiple health events (lung disease, heart disease, stroke, or cancer). Distinct depression and resilience trajectories were identified using latent growth mixture modeling (LGMM). These trajectories were compared on rates of mortality 4 years after the health events. Findings indicated that 4 trajectories best fit the data including resilience, emergent postevent depression, chronic pre-to-post depression, and depressed prior followed by improvement. Analyses demonstrate that multiple health events do not decrease rates of resilience but do increase the severity of symptoms among those on the emergent depression trajectory. Emergent depression increased mortality compared with all others but among those in this class, rates were not different in response to single versus multiple health events. Multiple major stressors do not reduce rates of resilience. The emergence of depression after health events does significantly increase risk for mortality regardless of the number of events. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. The ear, the eye, earthquakes and feature selection: listening to automatically generated seismic bulletins for clues as to the differences between true and false events.

    Science.gov (United States)

    Kuzma, H. A.; Arehart, E.; Louie, J. N.; Witzleben, J. L.

    2012-04-01

    excellent candidate from which to draw features that can be fed into machine learning algorithms since it contains a compact numerical representation of the information that humans need to evaluate events. The challenge in this work is that, although it is relatively easy to pick out earthquake arrivals in waveform data from a single station, when stations are combined the addition of background noise tends to confuse and overwhelm the listener. To solve this problem, we rely on techniques such as the slowing down of recordings without altering the pitch which are used by ethnomusicologists to understand highly complex rhythms and sounds. We work with professional musicians and recorders to mix the data from different seismic stations in a way which reduces noise and preserves the uniqueness of each station.

  8. The Unconstrained Event Bulletin (UEB) for the IMS Seismic Network Spaning the Period May 15-28, 2010: a New Resource for Algorithm Development and Testing

    Science.gov (United States)

    Brogan, R.; Young, C. J.; Ballard, S.

    2017-12-01

    A major problem with developing new data processing algorithms for seismic event monitoring is the lack of standard, high-quality "ground-truth" data sets to test against. The unfortunate effect of this is that new algorithms are often developed and tested with new data sets, making comparison of algorithms difficult and subjective. In an effort towards resolving this problem, we have developed the Unconstrained Event Bulletin (UEB), a ground-truth data set from the International Monitoring System (IMS) primary and auxiliary seismic networks for a two-week period in May 2010. All UEB analysis was performed by the same expert, who has more than 30 years of experience analyzing seismic data for nuclear explosion monitoring. We used the most complete International Data Centre (IDC) analyst-review event bulletin (the Late Event Bulletin or LEB) as a starting point for this analysis. To make the UEB more complete, we relaxed the minimum event definite criteria to the level of a pair of P-type and an S-type phases at a single station and using azimuth/slowness as defining. To add even more events that our analyst recognized and didn't want to omit, in rare cases, events were constructed using only 1 P-phase. Perhaps most importantly, on average our analyst spent more than 60 hours per day of data, far more than was possible in the production of the LEB. The result of all this was that while the LEB had 2,101 LEB events for the 2-week time period, we ended up with 11,435 events in the UEB, an increase of over 400%. New events are located all over the world and include both earthquakes and manmade events such as mining explosions. Our intent is to make our UEB data set openly available for all researchers to use for testing detection, correlation, and location algorithms, thus making it much easier to objectively compare different research efforts. Acknowledgement: Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and

  9. Parallel System Architecture (PSA): An efficient approach for automatic recognition of volcano-seismic events

    Science.gov (United States)

    Cortés, Guillermo; García, Luz; Álvarez, Isaac; Benítez, Carmen; de la Torre, Ángel; Ibáñez, Jesús

    2014-02-01

    Automatic recognition of volcano-seismic events is becoming one of the most demanded features in the early warning area at continuous monitoring facilities. While human-driven cataloguing is time-consuming and often an unreliable task, an appropriate machine framework allows expert technicians to focus only on result analysis and decision-making. This work presents an alternative to serial architectures used in classic recognition systems introducing a parallel implementation of the whole process: configuration, feature extraction, feature selection and classification stages are independently carried out for each type of events in order to exploit the intrinsic properties of each signal class. The system uses Gaussian Mixture Models (GMMs) to classify the database recorded at Deception Volcano Island (Antarctica) obtaining a baseline recognition rate of 84% with a cepstral-based waveform parameterization in the serial architecture. The parallel approach increases the results to close to 92% using mixture-based parameterization vectors or up to 91% when the vector size is reduced by 19% via the Discriminative Feature Selection (DFS) algorithm. Besides the result improvement, the parallel architecture represents a major step in terms of flexibility and reliability thanks to the class-focused analysis, providing an efficient tool for monitoring observatories which require real-time solutions.

  10. Single Event Rates for Devices Sensitive to Particle Energy

    Science.gov (United States)

    Edmonds, L. D.; Scheick, L. Z.; Banker, M. W.

    2012-01-01

    Single event rates (SER) can include contributions from low-energy particles such that the linear energy transfer (LET) is not constant. Previous work found that the environmental description that is most relevant to the low-energy contribution to the rate is a "stopping rate per unit volume" even when the physical mechanisms for a single-event effect do not require an ion to stop in some device region. Stopping rate tables are presented for four heavy-ion environments that are commonly used to assess device suitability for space applications. A conservative rate estimate utilizing limited test data is derived, and the example of SEGR rate in a power MOSFET is presented.

  11. Single-Event Effects in Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Ikpe, Stanley; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2015-01-01

    This report summarizes the NASA Electronic Parts and Packaging Program Silicon Carbide Power Device Subtask efforts in FY15. Benefits of SiC are described and example NASA Programs and Projects desiring this technology are given. The current status of the radiation tolerance of silicon carbide power devices is given and paths forward in the effort to develop heavy-ion single-event effect hardened devices indicated.

  12. Applications of heavy ion microprobe for single event effects analysis

    International Nuclear Information System (INIS)

    Reed, Robert A.; Vizkelethy, Gyorgy; Pellish, Jonathan A.; Sierawski, Brian; Warren, Kevin M.; Porter, Mark; Wilkinson, Jeff; Marshall, Paul W.; Niu, Guofu; Cressler, John D.; Schrimpf, Ronald D.; Tipton, Alan; Weller, Robert A.

    2007-01-01

    The motion of ionizing-radiation-induced rogue charge carriers in a semiconductor can create unwanted voltage and current conditions within a microelectronic circuit. If sufficient unwanted charge or current occurs on a sensitive node, a variety of single event effects (SEEs) can occur with consequences ranging from trivial to catastrophic. This paper describes the application of heavy ion microprobes to assist with calibration and validation of SEE modeling approaches

  13. A Search for Single Photon Events in Neutrino Interactions

    CERN Document Server

    Kullenberg, C.T.; Dimmery, D.; Tian, X.C.; Autiero, D.; Gninenko, S.; Rubbia, A.; Alekhin, S.; Astier, P.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P.W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Degaudenzi, H.; De Santo, A.; Del Prete, T.; Di Lella, L.; do Couto e Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G.J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kim, J.J.; Kirsanov, M.; Kulagin, S.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.M.; Ling, J.; Linssen, L.; Ljubičic, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Moorhead, G.F.; Naumov, D.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L.S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Popov, B.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Scott, A.M.; Seaton, M.B.; Sevior, M.; Sillou, D.; Soler, F.J.P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G.N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S.N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K.E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F.V.; Weisse, T.; Wilson, F.F.; Winton, L.J.; Wu, Q.; Yabsley, B.D.; Zaccone, H.; Zuber, K.; Zuccon, P.

    2012-01-01

    We present a search for neutrino-induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is $\\simeq 25$ GeV. The search is motivated by an excess of electron-like events in the 200--475 MeV energy region as reported by the MiniBOONE experiment. In NOMAD, photons are identified via their conversion to $e^+e^-$ in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined {\\it in situ} using control data samples prior to opening the `signal-box'. In the signal region, we observe {\\bf 155} events with a predicted background of {\\bf 129.2 $\\pm$ 8.5 $\\pm$ 3.3}. We interpret this as null evidence for excess of single...

  14. 3-D a Priori Model Constraints and Uncertainties for Improving Seismic Event Location

    Science.gov (United States)

    Flanagan, M. P.; Myers, S. C.; Pasyanos, M. E.; Schultz, C. A.

    2001-12-01

    We investigate our ability to improve seismic event location in the Middle East, North Africa, and Western Eurasia (MENAWE) by using an a priori 3-D velocity model for the crust and upper mantle in lieu of more commonly used 1-D Earth models. We develop our composite velocity model based on published literature: a global sediment thickness map, a regionalized crustal model based on geology and tectonics, and an upper mantle model [Pasyanos et al., 2001]. We test a variety of mantle velocity models developed either from teleseismic travel-times [Gudmundsson and Sambridge, 1998] or from geodynamic estimates of temperature, pressure, and composition [Nataf and Ricard, 1996]. Using a 3-D finite difference technique we compute travel times through the model and produce station-specific correction surfaces relative to iasp91. We then use these model-based correction surfaces as additional constraints in our event location algorithm to relocate a set of ground truth (GT) events (the 1991 Racha aftershock sequence). Myers and Schult [2000], using empirical kriged correction surfaces and a 1-D velocity model applied to a test network, reduced the average location bias of this aftershock sequence from 42 km (using a 1-D velocity model alone) to 13 km. With our model-based correction surfaces we reduce this bias from 42 to 26 km using the travel-time mantle model and from 42 to 10 km using the geodynamic mantle model. This is a significant result showing the power of a priori 3-D models to improve location to almost the same degree as empirical corrections, within the GT uncertainty bounds. This test relocation samples only one part of our MENAWE model, and we are continuing to test the model in other areas using geographically diverse GT events. A larger data set of GT0-GT10 events is being collected and will be used to further evaluate the effectiveness of the a priori model for improving event location accuracy. We also plan to explore a variety of validation techniques (e

  15. Analyzing System on A Chip Single Event Upset Responses using Single Event Upset Data, Classical Reliability Models, and Space Environment Data

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth; Campola, Michael; Xapsos, Michael

    2017-01-01

    We are investigating the application of classical reliability performance metrics combined with standard single event upset (SEU) analysis data. We expect to relate SEU behavior to system performance requirements. Our proposed methodology will provide better prediction of SEU responses in harsh radiation environments with confidence metrics. single event upset (SEU), single event effect (SEE), field programmable gate array devises (FPGAs)

  16. Response of the ionospheric electron density to different types of seismic events

    Directory of Open Access Journals (Sweden)

    Y. He

    2011-08-01

    Full Text Available The electron density data recorded by the Langmuir Probe Instrument (ISL, Instrument Sonde de Langmuir onboard the DEMETER satellite have been collected for nearly 4 yr (during 2006–2009 to perform a statistical analysis. During this time, more than 7000 earthquakes with a magnitude larger than or equal to 5.0 occurred all over the world. For the statistical studies, all these events have been divided into various categories on the basis of the seismic information, including Southern or Northern Hemisphere earthquakes, inland or sea earthquakes, earthquakes at different magnitude levels, earthquakes at different depth levels, isolated events and all events. To distinguish the pre-earthquake anomalies from the possible ionospheric anomalies related to the geomagnetic activity, the data were filtered with the Kp index. The statistical results obviously show that the electron density increases close to the epicentres both in the Northern and the Southern Hemisphere, but the position of the anomaly is slightly shifted to the north in the Northern Hemisphere and to the south in the Southern Hemisphere. The electron density related to both inland and sea earthquakes presents an anomaly approximately close to the epicentres, but the anomaly for sea earthquakes is more significant than for inland earthquakes. The intensity of the anomalies is enhanced when the magnitude increases and is reduced when the depth increases. A similar anomaly can also be seen in the statistical results concerning the isolated earthquakes. All these statistical results can help to better understand the preparation process of the earthquakes and their influence up to the ionospheric levels.

  17. Single event upsets caused by solar energetic heavy ions

    International Nuclear Information System (INIS)

    Tylka, A.J.; Adams, J.H. Jr.; Boberg, P.R.; Smith, E.C.

    1996-01-01

    The authors calculate single event upset (SEU) rates due to protons, alphas, and heavier ions in two satellite systems for the major solar particle events of 1989--92, using a new and complete analysis of GOES proton data and high-energy heavy-ion fluences from the University of Chicago Cosmic Ray Telescope on IMP-8. These measurements cover the entire range of energies relevant to SEU studies and therefore overcome shortcomings of previous studies, which relied upon theoretical or semi-empirical estimates of high-energy heavy-ion spectra. They compare the results to the observed SEU rates in these events. The SEU rates in one device were overwhelmingly dominated by protons. However, even after taking into account uncertainties in the ground-test cross-section data, the authors find that at least ∼45% of the SEUs in the other device must have been caused by heavy ions. The results demonstrate that both protons and heavy ions must be considered in order to make a reliable assessment of SEU vulnerabilities. Furthermore, the GOES/Chicago database of solar particle events provides a basis for making accurate solar particle SEU calculations and credible worst-case estimates. In particular, measurements of the historic solar particle events of October 1989 are used in worst week and worst day environment models in CREME96, a revision of NRL's Cosmic Ray Effects on MicroElectronics code

  18. Efficient Integration of Old and New Research Tools for Automating the Identification and Analysis of Seismic Reference Events

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Robert; Rivers, Wilmer

    2005-01-25

    any single computer program for seismic data analysis will not have all the capabilities needed to study reference events, since hese detailed studies will be highly specialized. It may be necessary to develop and test new algorithms, and then these special ;odes must be integrated with existing software to use their conventional data-processing routines. We have investigated two neans of establishing communications between the legacy and new codes: CORBA and XML/SOAP Web services. We have nvestigated making new Java code communicate with a legacy C-language program, geotool, running under Linux. Both methods vere successful, but both were difficult to implement. C programs on UNIX/Linux are poorly supported for Web services, compared vith the Java and .NET languages and platforms. Easier-to-use middleware will be required for scientists to construct distributed applications as easily as stand-alone ones. Considerable difficulty was encountered in modifying geotool, and this problem shows he need to use component-based user interfaces instead of large C-language codes where changes to one part of the program nay introduce side effects into other parts. We have nevertheless made bug fixes and enhancements to that legacy program, but t remains difficult to expand it through communications with external software.

  19. Fast recognition of single molecules based on single-event photon statistics

    International Nuclear Information System (INIS)

    Dong Shuangli; Huang Tao; Liu Yuan; Wang Jun; Zhang Guofeng; Xiao Liantuan; Jia Suotang

    2007-01-01

    Mandel's Q parameter, which is determined from single-event photon statistics, provides an alternative way to recognize single molecules with fluorescence detection, other than the second-order correlation function. It is shown that the Q parameter of an assumed ideal double-molecule fluorescence with the same average photon number as that of the sample fluorescence can act as the criterion for single-molecule recognition. The influence of signal-to-background ratio and the error estimates for photon statistics are also presented. We have applied this method to ascertain single Cy5 dye molecules within hundreds of milliseconds

  20. Preliminary study of the effects of fault properties and mining geometry on the stiffness of the loading system in fault slip seismic events as a basis for identifying situations prone to seismic activity.

    CSIR Research Space (South Africa)

    Esterhuizen, GS

    1994-01-01

    Full Text Available The mechanism of most seismic events is shear displacement along geological faults. Seismicity occurs if the slip takes place violently and kinetic energy is released into the surrounding rock. The rock surrounding the fault plane may be seen...

  1. Analysis of experiment testing technology for single event effects in China

    International Nuclear Information System (INIS)

    He Chaohui

    2001-01-01

    The merit and demerit of simulation source were analyzed for Single Event Effects (SEE) experiment testing in China. Laboratory experiment systems for SEE were brief introduced and requests for SEE test system were emphasize analyzed. Test systems were presented for Single Event Upset, Single Event Latch-up, Single Event Burnout and Single Event Gate-Rupture. The attention should be in mind in SEE experiments were discussed

  2. Time-resolved gamma spectroscopy of single events

    Science.gov (United States)

    Wolszczak, W.; Dorenbos, P.

    2018-04-01

    In this article we present a method of characterizing scintillating materials by digitization of each individual scintillation pulse followed by digital signal processing. With this technique it is possible to measure the pulse shape and the energy of an absorbed gamma photon on an event-by-event basis. In contrast to time-correlated single photon counting technique, the digital approach provides a faster measurement, an active noise suppression, and enables characterization of scintillation pulses simultaneously in two domains: time and energy. We applied this method to study the pulse shape change of a CsI(Tl) scintillator with energy of gamma excitation. We confirmed previously published results and revealed new details of the phenomenon.

  3. Validation of an "Intelligent Mouthguard" Single Event Head Impact Dosimeter.

    Science.gov (United States)

    Bartsch, Adam; Samorezov, Sergey; Benzel, Edward; Miele, Vincent; Brett, Daniel

    2014-11-01

    Dating to Colonel John Paul Stapp MD in 1975, scientists have desired to measure live human head impacts with accuracy and precision. But no instrument exists to accurately and precisely quantify single head impact events. Our goal is to develop a practical single event head impact dosimeter known as "Intelligent Mouthguard" and quantify its performance on the benchtop, in vitro and in vivo. In the Intelligent Mouthguard hardware, limited gyroscope bandwidth requires an algorithm-based correction as a function of impact duration. After we apply gyroscope correction algorithm, Intelligent Mouthguard results at time of CG linear acceleration peak correlate to the Reference Hybrid III within our tested range of pulse durations and impact acceleration profiles in American football and Boxing in vitro tests: American football, IMG=1.00REF-1.1g, R2=0.99; maximum time of peak XYZ component imprecision 3.6g and 370 rad/s2; maximum time of peak azimuth and elevation imprecision 4.8° and 2.9°; maximum average XYZ component temporal imprecision 3.3g and 390 rad/s2. Boxing, IMG=1.00REF-0.9 g, R2=0.99, R2=0.98; maximum time of peak XYZ component imprecision 3.9 g and 390 rad/s2, maximum time of peak azimuth and elevation imprecision 2.9° and 2.1°; average XYZ component temporal imprecision 4.0 g and 440 rad/s2. In vivo Intelligent Mouthguard true positive head impacts from American football players and amateur boxers have temporal characteristics (first harmonic frequency from 35 Hz to 79 Hz) within our tested benchtop (first harmonic frequencyIntelligent Mouthguard qualifies as a single event dosimeter in American football and Boxing.

  4. Single Event Upset Studies Using the ATLAS SCT

    CERN Document Server

    Weidberg, A R; The ATLAS collaboration

    2013-01-01

    Single Event Upsets (SEU) are expected to occur during high luminosity running of the ATLAS SemiConductor Tracker (SCT). The SEU cross sections were measured in pion beams with momenta in the range 200 to 465 MeV/c and proton test beams at 24 GeV/c but the extrapolation to LHC conditions is non-trivial because of the range of particle types and momenta. The SEUs studied occur in the \\emph{p-i-n} photodiode and the registers in the ABCD chip. Comparisons between predicted SEU rates and those measured from ATLAS data are presented. The implications for ATLAS operation are discussed.

  5. Single Event Upset Studies Using the ATLAS SCT

    CERN Document Server

    Dafinca, A; The ATLAS collaboration; Weidberg, A R

    2014-01-01

    Single Event Upsets (SEU) are expected to occur during high luminosity running of the ATLAS SemiConductor Tracker (SCT). The SEU cross sections were measured in pion beams with momenta in the range 200 to 465 MeV/c and proton test beams at 24 GeV/c but the extrapolation to LHC conditions is non-trivial because of the range of particle types and momenta. The SEUs studied occur in the p-i-n photodiode and the registers in the ABCD chip. Comparisons between predicted SEU rates and those measured from ATLAS data are presented. The implications for ATLAS operation are discussed

  6. Single-event burnout of power bipolar junction transistors

    International Nuclear Information System (INIS)

    Titus, J.L.; Johnson, G.H.; Schrimpf, R.D.; Galloway, K.F.

    1991-01-01

    Experimental evidence of single-event burnout of power bipolar junctions transistors (BJTs) is reported for the first time. Several commercial power BJTs were characterized in a simulated cosmic ray environment using mono-energetic ions at the tandem Van de Graaff accelerator facility at Brookhaven National Laboratory. Most of the device types exposed to this simulated environment exhibited burnout behavior. In this paper the experimental technique, data, and results are presented, while a qualitative model is used to help explain those results and trends observed in this experiment

  7. Source parameters of seismic events potentially associated with damage in block 33/34 of the Kiirunavaara mine (Sweden)

    Science.gov (United States)

    Nordström, Emilia; Dineva, Savka; Nordlund, Erling

    2017-12-01

    Forty-six mining-induced seismic events with moment magnitude between -1.2 and 2.1 that possibly caused damage were studied. The events occurred between 2008 and 2013 at mining level 850-1350 m in the Kiirunavaara Mine (Sweden). Hypocenter locations were refined using from 6 to 130 sensors at distances of up to 1400 m. The source parameters of the events were re-estimated using spectral analysis with a standard Brune model (slope -2). The radiated energy for the studied events varied from 4.7 × 10-1 to 3.8 × 107 J, the source radii from 4 to 110 m, the apparent stress from 6.2 × 102 to 1.1 × 106 Pa, energy ratio ( E s/ E p) from 1.2 to 126, and apparent volume from 1.8 × 103 to 1.1 × 107 m3. 90% of the events were located in the footwall, close to the ore contact. The events were classified as shear/fault slip (FS) or non-shear (NS) based on the E s/ E p ratio (>10 or <10). Out of 46 events 15 events were classified as NS located almost in the whole range between 840 and 1360 m, including many events below the production. The rest 31 FS events were concentrated mostly around the production levels and slightly below them. The relationships between some source parameters and seismic moment/moment magnitude showed dependence on the type of the source mechanism. The energy and the apparent stress were found to be three times larger for FS events than for NS events.

  8. Depth Discrimination Using Rg-to-Sg Spectral Amplitude Ratios for Seismic Events in Utah Recorded at Local Distances

    Energy Technology Data Exchange (ETDEWEB)

    Tibi, Rigobert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Koper, Keith D. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Geology and Geophysics; Pankow, Kristine L. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Geology and Geophysics; Young, Christopher J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-03-20

    Short-period fundamental-mode Rayleigh waves (Rg) are commonly observed on seismograms of anthropogenic seismic events and shallow, naturally occurring tectonic earthquakes (TEs) recorded at local distances. In the Utah region, strong Rg waves traveling with an average group velocity of about 1.8 km/s are observed at ~1 Hz on waveforms from shallow events ( depth<10 km ) recorded at distances up to about 150 km. At these distances, Sg waves, which are direct shear waves traveling in the upper crust, are generally the dominant signals for TEs. Here in this study, we leverage the well-known notion that Rg amplitude decreases dramatically with increasing event depth to propose a new depth discriminant based on Rg-to-Sg spectral amplitude ratios. The approach is successfully used to discriminate shallow events (both earthquakes and anthropogenic events) from deeper TEs in the Utah region recorded at local distances ( <150 km ) by the University of Utah Seismographic Stations (UUSS) regional seismic network. Using Mood’s median test, we obtained probabilities of nearly zero that the median Rg-to-Sg spectral amplitude ratios are the same between shallow events on the one hand (including both shallow TEs and anthropogenic events), and deeper earthquakes on the other, suggesting that there is a statistically significant difference in the estimated Rg-to-Sg ratios between the two populations. We also observed consistent disparities between the different types of shallow events (e.g., mining blasts vs. mining-induced earthquakes), implying that it may be possible to separate the subpopulations that make up this group. Lastly, this suggests that using local distance Rg-to-Sg spectral amplitude ratios one can not only discriminate shallow events from deeper events but may also be able to discriminate among different populations of shallow events.

  9. Study of site effect using mining induced seismic events and ambient noise from Karviná region

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Lyubushin, A. A.

    2008-01-01

    Roč. 5, č. 2 (2008), s. 105-113 ISSN 1214-9705. [Polish-Czech-Slovakian Symposium on Mining and Environmental Geophysics/31./. Janov nad Nisou, 24.09.2007-27.09.2007] R&D Projects: GA ČR GA105/07/0878 Institutional research plan: CEZ:AV0Z30860518 Keywords : mining induced seismic event * ambient noise * frequency analysis Subject RIV: DC - Siesmology, Volcanology, Earth Structure http://www.irsm.cas.cz

  10. Changes and challenges following the 1997 Colfiorito earthquake: the evolution of the use of the Internet for large seismic events

    Directory of Open Access Journals (Sweden)

    R. Camassi

    2008-06-01

    Full Text Available The September 26, 1997 Central Italy earthquake represents the first Italian large seismic event on the occasion of which Internet was intensively exploited to exchange and disseminate data, information and news. The paper illustrates how national and international seismological institutions disseminate information about earthquakes ten years ago. A web evolution is sketched, and some features that can be of interest today in the seismological community are presented.

  11. Analysis of the effects of corrosion probe on riser 241-AN-102-WST-16 during seismic event

    International Nuclear Information System (INIS)

    ZIADA, H.H.

    1998-01-01

    This analysis supports the installation activity of the corrosion probe in Tank 241-AN-102. The probe is scheduled to be installed in Riser 241-AN-102-WST-16 (formerly known as Riser 15B). The purpose of this analysis is to evaluate the potential effect of the corrosion probe on the riser during a credible seismic event. The previous analysis (HNF 1997a) considered only pump jet impingement loading

  12. Nonlinear Methodologies for Identifying Seismic Event and Nuclear Explosion Using Random Forest, Support Vector Machine, and Naive Bayes Classification

    Directory of Open Access Journals (Sweden)

    Longjun Dong

    2014-01-01

    Full Text Available The discrimination of seismic event and nuclear explosion is a complex and nonlinear system. The nonlinear methodologies including Random Forests (RF, Support Vector Machines (SVM, and Naïve Bayes Classifier (NBC were applied to discriminant seismic events. Twenty earthquakes and twenty-seven explosions with nine ratios of the energies contained within predetermined “velocity windows” and calculated distance are used in discriminators. Based on the one out cross-validation, ROC curve, calculated accuracy of training and test samples, and discriminating performances of RF, SVM, and NBC were discussed and compared. The result of RF method clearly shows the best predictive power with a maximum area of 0.975 under the ROC among RF, SVM, and NBC. The discriminant accuracies of RF, SVM, and NBC for test samples are 92.86%, 85.71%, and 92.86%, respectively. It has been demonstrated that the presented RF model can not only identify seismic event automatically with high accuracy, but also can sort the discriminant indicators according to calculated values of weights.

  13. Seismic detection. Part II. Nuclear events. Volume 1. 1970--1972 (a bibliography with abstracts). Report for Jun 1970--1972

    International Nuclear Information System (INIS)

    Habercom, G.E. Jr.

    1976-03-01

    Methods of seismic detection of nuclear events are investigated in these Government-sponsored research reports. (This updated bibliography contains 135 abstracts, none of which are new entries to the previous edition.) For general seismic detection, see Part 1, NTIS/PS-76/0206

  14. A Trial for Detecting the Temporal Variation in Seismic Velocity Accompanied by a Slow Slip Event using Seismic Interferometry of Ambient Noise

    Science.gov (United States)

    Uemura, Miyuu; Ito, Yoshihiro; Ohta, Kazuaki; Hino, Ryota; Shinohara, Masanao

    2017-04-01

    Seismic interferometry is one of the most effective techniques to detect temporal variations in seismic velocity before or after a large earthquake. Some previous studies have been reported on seismic velocity reduction due to the occurrence of large earthquakes (e.g., Wegler et al., 2009; Yamada et al., 2010) as well as preceding them (e.g., Lockner et al., 1977; Yoshimitsu et al., 2009). However, there have only been a few studies thus far which attempt to detect seismic velocity changes associated with slow slip events (SSEs). In this study, we focus on applying seismic interferometry to ambient noise data from ocean bottom seismometers (OBSs) deployed near a subduction zone. Between the end of January 2011 and the largest foreshock occurring on March 9th that precedes the March 11, 2011 Tohoku-Oki earthquake, SSEs and low-frequency tremors were detected offshore Miyagi Prefecture (Ito et al., 2013, 2015; Katakami et al., 2016). We applied our seismic interferometry analysis using ambient noise to recordings from 17 OBS stations that were installed in the vicinity of the 2011 Tohoku-Oki earthquake source region, and only considered the recordings from before that major earthquake. All the OBSs are short-period seismometers with three components which have an eigenfrequency of 4.5 Hz. These OBSs were deployed offshore Miyagi Prefecture between November 2010 and April 2011. Before proceeding with the seismic interferometry analysis, we needed to estimate the two horizontal components of the original deployment orientation for 13 OBSs in (we could not estimate them for 4 OBSs). To obtain the OBS orientation, we used particle orbits of some direct P waves from selected tectonic earthquakes, in order to extract one vertical and two horizontal components. Then, the seismic interferometry analysis consisted of the following steps. First, we applied a band-pass filter of 0.25-2.0 Hz and one-bit technique to the ambient noise signal. Second, we calculated auto

  15. Optically-based Sensor System for Critical Nuclear Facilities Post-Event Seismic Structural Assessment

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Petrone, Floriana [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Buckle, Ian [Univ. of Nevada, Reno, NV (United States); Wu, Suiwen [Univ. of Nevada, Reno, NV (United States); Coates, Jason [California State Univ., Chico, CA (United States)

    2017-09-30

    The U.S. Department of Energy (DOE) has ownership and operational responsibility for a large enterprise of nuclear facilities that provide essential functions to DOE missions ranging from national security to discovery science and energy research. These facilities support a number of DOE programs and offices including the National Nuclear Security Administration, Office of Science, and Office of Environmental Management. With many unique and “one of a kind” functions, these facilities represent a tremendous national investment, and assuring their safety and integrity is fundamental to the success of a breadth of DOE programs. Many DOE critical facilities are located in regions with significant natural phenomenon hazards including major earthquakes and DOE has been a leader in developing standards for the seismic analysis of nuclear facilities. Attaining and sustaining excellence in nuclear facility design and management must be a core competency of the DOE. An important part of nuclear facility management is the ability to monitor facilities and rapidly assess the response and integrity of the facilities after any major upset event. Experience in the western U.S. has shown that understanding facility integrity after a major earthquake is a significant challenge which, lacking key data, can require extensive effort and significant time. In the work described in the attached report, a transformational approach to earthquake monitoring of facilities is described and demonstrated. An entirely new type of optically-based sensor that can directly and accurately measure the earthquake-induced deformations of a critical facility has been developed and tested. This report summarizes large-scale shake table testing of the sensor concept on a representative steel frame building structure, and provides quantitative data on the accuracy of the sensor measurements.

  16. Determination of the seismic moment tensor for local events in the South Shetland Islands and Bransfield Strait

    International Nuclear Information System (INIS)

    Guidarelli, M.; Panza, G.F.

    2005-06-01

    We present the results of the analysis for a set of earthquakes recorded in the Bransfield Strait and the South Shetland Islands in the period 1997-1998, to determine focal mechanisms and source time functions. Events with magnitudes between 3 and 5.6 have been analysed, and the source parameters have been retrieved using a robust methodology (INPAR) that allows the reliable inversion of a limited number of noisy records. This methodology is particularly important in oceanic environments, where the presence of seismic noise and the small number of stations makes it difficult to analyse small magnitude events. (author)

  17. Seismic Calibration of Group 1 IMS Stations in Eastern Asia for Improved IDC Event Location

    National Research Council Canada - National Science Library

    Murphy, J. R; Rodi, W. L; Johnson, M; Sultanov, J. D; Bennett, T. J; Toksoz, M. N; Ovtchinnikov, V; Barker, B. W; Rosca, A. M; Shchukin, Y

    2006-01-01

    .... In order to establish a robust nuclear test monitoring capability, it is necessary to calibrate the IMS seismic stations used in monitoring, to account for systematic deviations from the nominal travel time curves...

  18. Reducing Systematic Errors for Seismic Event Locations Using a Model Incorporating Anisotropic Regional Structures

    National Research Council Canada - National Science Library

    Smith, Gideon P; Wiens, Douglas A

    2006-01-01

    ...) to predict travel times of P-wave propagation at distances of 2 - 14 degrees. At such distances, the phase Pn is in the seismic phase that is most frequently reported and that thus controls the location accuracy...

  19. Verifying single-station seismic approaches using Earth-based data: Preparation for data return from the InSight mission to Mars

    Science.gov (United States)

    Panning, Mark P.; Beucler, Éric; Drilleau, Mélanie; Mocquet, Antoine; Lognonné, Philippe; Banerdt, W. Bruce

    2015-03-01

    The planned InSight mission will deliver a single seismic station containing 3-component broadband and short-period sensors to the surface of Mars in 2016. While much of the progress in understanding the Earth and Moon's interior has relied on the use of seismic networks for accurate location of sources, single station approaches can be applied to data returned from Mars in order to locate events and determine interior structure. In preparation for the data return from InSight, we use a terrestrial dataset recorded at the Global Seismic Network station BFO, located at the Black Forest Observatory in Germany, to verify an approach for event location and structure determination based on recordings of multiple orbit surface waves, which will be more favorable to record on Mars than Earth due to smaller planetary radius and potentially lower background noise. With this approach applied to events near the threshold of observability on Earth, we are able to determine epicentral distance within approximately 1° (corresponding to ∼60 km on Mars), and origin time within ∼30 s. With back azimuth determined from Rayleigh wave polarization, absolute locations are determined generally within an aperture of 10°, allowing for localization within large tectonic regions on Mars. With these locations, we are able to recover Earth mantle structure within ±5% (the InSight mission requirements for martian mantle structure) using 1D travel time inversions of P and S travel times for datasets of only 7 events. The location algorithm also allows for the measurement of great-circle averaged group velocity dispersion, which we measure between 40 and 200 s to scale the expected reliable frequency range of the InSight data from Earth to Mars data. Using the terrestrial data, we are able to resolve structure down to ∼200 km, but synthetic tests demonstrate we should be able to resolve martian structure to ∼400 km with the same frequency content given the smaller planetary size.

  20. Spatial clustering and repeating of seismic events observed along the 1976 Tangshan fault, north China

    Science.gov (United States)

    Li, Le; Chen, Qi-Fu; Cheng, Xin; Niu, Fenglin

    2007-12-01

    Spatial and temporal features of the seismicity occurring along the Tangshan fault in 2001-2006 were investigated with data recorded by the Beijing metropolitan digital Seismic Network. The relocated seismicity with the double difference method clearly exhibits a dextral bend in the middle of the fault. More than 85% of the earthquakes were found in the two clusters forming the northern segment where relatively small coseismic slips were observed during the 1976 M7.8 earthquake. The b values calculated from the seismicity occurring in the northern and southern segment are 1.03 +/- 0.02 and 0.85 +/- 0.03, respectively. The distinct seismicity and b values are probably the collective effect of the fault geometry and the regional stress field that has an ENE-WSW oriented compression. Using cross-correlation and fine relocation analyses, we also identified a total of 21 doublets and 25 multiplets that make up >50% of the total seismicity. Most of the sequences are aperiodic with recurrence intervals varying from a few minutes to hundreds of days. Based on a quasi-periodic sequence, we obtained a fault slip rate of <=2.6 mm/yr at ~15 km, which is consistent with surface GPS measurements.

  1. Joint interpretation of high-precision tilt data and mining induced seismic events recorded underground in deep level gold mine in South Africa

    Science.gov (United States)

    Milev, Alexander; Share, Pieter; Durrheim, Ray; Naoi, Makoto; Nakatani, Masao; Yabe, Yasuo; Ogasawara, Hiroshi

    2013-04-01

    Seismicity associated with deep-level mining has for long been a problem, leading to rockburst and other similar hazards. Several studies have been completed in an attempt to minimize the total amount of seismicity. In this study high resolution measurements of ground tilting in combination with seismic monitoring is used to observe how the rock mass responds to mining. A good correspondence between the coseismic and the aseismic tilt was found. The rate of coseismic and aseismic tilt, as well as seismicity recorded by the mine seismic network, are approximately constant until the daily blasting time, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events, the coseismic and aseismic tilt shows a rapid increase. In an attempt to distinguish between the different mechanisms of tilting two types of events were recognized. The "fast" seismic events characterized with sharp increase of the tilt during the seismic rupture and "slow" seismic events characterized by creep type post seismic deformations. Tilt behaviour before and after a seismic event was also analysed. The fact that no recognizable aftertilt was observed for more of the "fast" seismic events means that there is no gradual release of stress and an associated continuous strain rate change afterwards. It can therefore be concluded that a large seismic event causes a rapid change in the state of stress rather than a gradual change in the strain rate. The mechanism of the observed "slow" seismic events is more complicated. Although several explanations have been proposed, a suggestion for further work could be to investigate the presence of "slow" events in or after blasting time more closely. During the monitoring period a seismic event with MW 2.2 occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emission network. More than 21,000 AE aftershocks were

  2. Translocation events in a single-walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    He Jin; Lindsay, Stuart [Biodesign Institute, Arizona State University, Tempe, AZ 85287 (United States); Liu Hao [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287 (United States); Pang Pei; Cao Di, E-mail: jinhe@asu.ed [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States)

    2010-11-17

    Translocation of DNA oligomers through a single-walled carbon nanotube was demonstrated recently. Translocation events are accompanied by giant current pulses, the origin of which remains obscure. Here, we show that the introduction of a nucleotide, guanosine triphosphate, alone into the input reservoir of a carbon nanotube nanofluidic device also gives giant current pulses. Taken together with data on oligomer translocation, these new results suggest that the pulse width has a nonlinear, power-law dependence on the number of nucleotides in a DNA molecule. We have also measured the time for the onset of DNA translocation pulses after bias reversal, finding that the time for the onset of translocation is directly proportional to the period of the bias reversal.

  3. Translocation events in a single-walled carbon nanotube

    International Nuclear Information System (INIS)

    He Jin; Lindsay, Stuart; Liu Hao; Pang Pei; Cao Di

    2010-01-01

    Translocation of DNA oligomers through a single-walled carbon nanotube was demonstrated recently. Translocation events are accompanied by giant current pulses, the origin of which remains obscure. Here, we show that the introduction of a nucleotide, guanosine triphosphate, alone into the input reservoir of a carbon nanotube nanofluidic device also gives giant current pulses. Taken together with data on oligomer translocation, these new results suggest that the pulse width has a nonlinear, power-law dependence on the number of nucleotides in a DNA molecule. We have also measured the time for the onset of DNA translocation pulses after bias reversal, finding that the time for the onset of translocation is directly proportional to the period of the bias reversal.

  4. Single event upset immunity of strontium bismuth tantalate ferroelectric memories

    International Nuclear Information System (INIS)

    Benedetto, J.M.; Derbenwick, G.F.; Cuchiaro, J.D.

    1999-01-01

    An embedded 1Kbit non-volatile (NV) serial memory manufactured with strontium bismuth tantalate (SBT) ferroelectric (FE) technology was shown to be immune to effects of heavy ion irradiation. The memories did not lose any data in the non-volatile mode when exposed to xenon (maximum effective LET of 128 MeV-cm 2 /mg and a total fluence of 1.5 x 10 7 ions/cm 2 ). The ferroelectric memories also did not exhibit any loss in the ability to rewrite new data into the memory bits, indicating that no significant degradation of the FE dipoles occurred as a result of the heavy ion exposure. The fast read/write times of FE memories also means that single event gate rupture is unlikely to occur in this technology

  5. Examining the Effect of Temperature, Pressure, Seismicity and Diffuse Fluid Flow on Floc Events at Axial Seamount

    Science.gov (United States)

    Rahman, M.; Crone, T. J.; Knuth, F.; Garcia, C.; Soule, D. C.; Fatland, R.

    2017-12-01

    Flocculation (floc) events are characterized by the ejection of bacterial material, possibly associated with thermophiles originating from warmer sub-seafloor habitats, into the water column. These events are anecdotally linked to magmatic and tectonic processes common in mid-ocean ridge seafloor environments. However, little is known about the relationship between flocculation events and other potentially triggering processes. The Cabled Array at Axial Seamount provides a suite of interdisciplinary real-time datasets to examine system-level processes governing the volcanic marine environment. The eruption at Axial Seamount in 2015 creates an opportunity to study this volcanic system as it evolves post eruption and identify the relationships between the temperature, pressure, seismicity and the biological response. The Diffuse Vent Fluid 3-D Temperature Array (TMPSF), located within the ASHES hydrothermal vent field at Axial Seamount, uses 24 separate sensors to provide a 3-dimensional distribution of diffuse flow temperatures near the Mushroom hydrothermal vent. Preliminary analysis suggests that the temperature signal is strongly influenced by tides observed using the ocean bottom pressure sensors, which may be related to either gradual shifts in tidal currents above the seafloor, or related to subsurface flux. CamHD, also located within the ASHES field, produces high definition video data, which we analyze to identify changes in water column floc concentration. These data streams allow us to examine the controls on the temperature signal and the associated correlations with microbial seafloor processes. We are currently examining the flocculation event identified in Crone (2016) to determine its relationship to changes in seawater temperatures near the seafloor, seismic activity and seafloor pressure. We will use this proxy to examine other CamHD data and determine if subsequent flocculation events have occurred and if they have a similar relationship to local

  6. New observations of displacement steps associated with volcano seismic long-period events, constrained by step table experiments

    Science.gov (United States)

    Thun, Johannes; Lokmer, Ivan; Bean, Christopher J.

    2015-05-01

    Long-period (LP) volcano seismic events often precede volcanic eruptions and are viewed with considerable interest in hazard assessment. They are usually thought to be associated with resonating fluid-filled conduits although alternative models involving material failure have recently been proposed. Through recent field experiments, we uncovered a step-like displacement component associated with some LP events, outside the spectral range of the typically narrow-band analysis for this kind of event. Bespoke laboratory experiments with step tables show that steps of the order of a few micrometers can be extracted from seismograms, where long-period noise is estimated and removed with moving median filters. Using these constraints, we observe step-like ground deformation in LP recordings near the summits of Turrialba and Etna Volcanoes. This represents a previously unobserved static component in the source time history of LP events, with implications for the underlying source process.

  7. Relationship between the focal mechanism of magnitude ML 3.3 seismic event induced by mining and distribution of peak ground velocity

    Directory of Open Access Journals (Sweden)

    Dubiński Józef

    2017-01-01

    Full Text Available The relationship between seismic radiation pattern generated by a strong mining induced seismic event and the distribution of peak ground velocity in the epicenter area has been presented. It was a seismic event with the local magnitude ML = 3.3 occurred on June 21, 2016 in the Upper Silesian Coal Basin (USCB in Marcel Mine. Calculated values of the peak ground velocity, taking into account the amplification coefficient, were the basis for the development of the PGVHamp map. The resulting distribution of PGVHamp isolines and the measured velocity amplitudes point to significant differences. That fact indicates that some additional factors can impact on the seismic effect observed on the surface. One of them could be a focal mechanism of seismic event. Focal mechanism of the M=3.3 induced seismic tremor, were calculated by the moment tensor inversion method. The tremor was characterized by a normal slip mechanism with 87% shear component. Comparison of seismic pattern for S-wave at individual stations allowed confirms a relation between directionality of the seismic radiation pattern for S-wave and the recorded peak ground velocities and explain the observed anomaly.

  8. Single event effect testing of the Intel 80386 family and the 80486 microprocessor

    International Nuclear Information System (INIS)

    Moran, A.; LaBel, K.; Gates, M.; Seidleck, C.; McGraw, R.; Broida, M.; Firer, J.; Sprehn, S.

    1996-01-01

    The authors present single event effect test results for the Intel 80386 microprocessor, the 80387 coprocessor, the 82380 peripheral device, and on the 80486 microprocessor. Both single event upset and latchup conditions were monitored

  9. Complex Dynamic Scene Perception: Effects of Attentional Set on Perceiving Single and Multiple Event Types

    Science.gov (United States)

    Sanocki, Thomas; Sulman, Noah

    2013-01-01

    Three experiments measured the efficiency of monitoring complex scenes composed of changing objects, or events. All events lasted about 4 s, but in a given block of trials, could be of a single type (single task) or of multiple types (multitask, with a total of four event types). Overall accuracy of detecting target events amid distractors was…

  10. Evidence of a Large Triggered Event in the Nepal Himalaya Following the Gorkha Earthquake: Implications Toward Enhanced Seismic Hazard

    Science.gov (United States)

    Mandal, Prantik

    2018-03-01

    A DC (double couple) constrained multiple point-source moment-tensor inversion is performed on the band-passed (0.008-0.10 Hz) displacement data of the 25 April (M w 7.8) 2015 Nepal mainshock, from 17 broadband stations in India. Our results reveal that the 25 April event (strike = 324°, dip = 14°, rake = 88°) ruptured the north-dipping main Himalayan thrust (MHT) at 16 km depth. We modeled the Coulomb failure stress changes (ΔCFS) produced by the slip on the fault plane of the 25 April Nepal mainshock. A strong correlation with occurrences of aftershocks and regions of increased positive ΔCFS is obtained below the aftershock zone of the 2015 Nepal mainshock. We notice that predicted ΔCFS at 16 km depth show a positive Coulomb stress of 0.06 MPa at the location of the 12 May 2015 event. These small modeled stress changes can lead to trigger events if the crust is already near to failure, but these small stresses can also advance the occurrence of future earthquakes. The main finding of our ΔCFS modeling implies that the 25 April event increased the Coulomb stress changes by 0.06 MPa at 16 km depth below the site of the 12 May event, and thus, this event can be termed as triggered. We propose that the seismic hazard in the Himalaya is not only caused by the mainshock slip on the MHT; rather, the occurrence of large triggered event on the MHT can also enhance our understanding of the seismic hazard in the Nepal Himalaya.

  11. Digital single-channel seismic-reflection data from western Santa Monica basin

    Science.gov (United States)

    Normark, William R.; Piper, David J.W.; Sliter, Ray W.; Triezenberg, Peter; Gutmacher, Christina E.

    2006-01-01

    During a collaborative project in 1992, Geological Survey of Canada and United States Geological Survey scientists obtained about 850 line-km of high-quality single-channel boomer and sleeve-gun seismic-reflection profiles across Hueneme, Mugu and Dume submarine fans, Santa Monica Basin, off southern California. The goals of this work were to better understand the processes that lead to the formation of sandy submarine fans and the role of sea-level changes in controlling fan development. This report includes a trackline map of the area surveyed, as well as images of the sleeve-gun profiles and the opportunity to download both images and digital data files (SEG-Y) of all the sleeve-gun profiles.

  12. Comparison of single event upset rates for microelectronic memory devices during interplanetary solar particle events

    Science.gov (United States)

    Mckerracher, P. L.; Kinnison, J. D.; Maurer, R. H.

    1993-01-01

    Variability in the methods and models used for single event upset calculations in microelectronic memory devices can lead to a range of possible upset rates. Using heavy ion and proton data for selected DRAM and SRAM memories, we have calculated an array of upset rates in order to compare the Adams worst case interplanetary solar flare model to a model proposed by scientists at the Jet Propulsion Laboratory. In addition, methods of upset rate calculation are compared: the Cosmic Ray Effects on Microelectronics CREME code and a Monte Carlo algorithm developed at the Applied Physics Laboratory. The results show that use of a more realistic, although still conservative, model of the space environment can have significant cost saving benefits.

  13. Study on energy distributions of strong seismic events in the USCB

    Directory of Open Access Journals (Sweden)

    Bracławska Agnieszka

    2017-06-01

    Full Text Available The paper presents the statistical analysis of energy distribution of strong seismic shocks (energy E ≥ 105 J occurred in the Upper Silesian Coal Basin which is one of the most seismically active mining areas in the world. In the USCB tremor epicenters do not occur uniformly throughout the whole basin but group in several regions belonging to different structural units and are separated by regions where strong shocks are not observed. The aim of the studies was to determine the modality of the energy distributions and to compare the modal types in regions of the USCB where the shocks epicenters cluster. An analysis was made for shocks with energies equal to or greater than 105 J recorded by Upper Silesian Regional Seismological Network operated by Central Mining Institute (CMI, which took place between 1987 – 2012. The analysis has proven the bimodality of seismic energy distribution in the three of five studied areas of the Upper Silesian Coal Basin. The Gumbel’s distribution II type best fit the experimental energy distribution for almost all studied tectonic units except the main syncline area, where the Gumbel’s distribution I type matched better the low-energy mode. This is due to too short time window, causing a shortage of the strongest shocks in seismic catalogue.

  14. Study on energy distributions of strong seismic events in the USCB

    Science.gov (United States)

    Bracławska, Agnieszka; Idziak, Adam F.

    2017-06-01

    The paper presents the statistical analysis of energy distribution of strong seismic shocks (energy E ≥ 105 J) occurred in the Upper Silesian Coal Basin which is one of the most seismically active mining areas in the world. In the USCB tremor epicenters do not occur uniformly throughout the whole basin but group in several regions belonging to different structural units and are separated by regions where strong shocks are not observed. The aim of the studies was to determine the modality of the energy distributions and to compare the modal types in regions of the USCB where the shocks epicenters cluster. An analysis was made for shocks with energies equal to or greater than 105 J recorded by Upper Silesian Regional Seismological Network operated by Central Mining Institute (CMI), which took place between 1987 - 2012. The analysis has proven the bimodality of seismic energy distribution in the three of five studied areas of the Upper Silesian Coal Basin. The Gumbel's distribution II type best fit the experimental energy distribution for almost all studied tectonic units except the main syncline area, where the Gumbel's distribution I type matched better the low-energy mode. This is due to too short time window, causing a shortage of the strongest shocks in seismic catalogue.

  15. Examples of rotational component records of mining induced seismic events from Karviná region

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Knejzlík, Jaromír

    2012-01-01

    Roč. 9, č. 2 (2012), s. 173-178 ISSN 1214-9705 Institutional support: RVO:68145535 Keywords : rotational component * rotational seismometer * mining induced seismicity Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/02_12/7_Kalab_Knejzlik.pdf

  16. Finite seismic source parameters inferred from stopping phases for selected events of West Bohemia 2000 swarm

    Czech Academy of Sciences Publication Activity Database

    Kolář, Petr; Růžek, Bohuslav

    2012-01-01

    Roč. 9, č. 4 (2012), s. 435-447 ISSN 1214-9705 R&D Projects: GA AV ČR(CZ) IAA300120805; GA ČR GAP210/10/1728 Institutional support: RVO:67985530 Keywords : finite seismic source * stopping phases * West Bohemia earthquke swarm Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.530, year: 2011

  17. An improved system of detecting single event effect in SRAM

    International Nuclear Information System (INIS)

    Tong Teng; Wang Xiaohui; Zhang Zhangang; Liu Tianqi; Gu Song; Yang Zhenlei; Su Hong; Liu Jie

    2014-01-01

    The material research center in Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS) have made a fruitful achievements in the research of single event effects (SEEs) occurring in static random access memory (SRAM). However, there are some drawbacks exist in the two systems of detecting SEE owning by the material research center. Therefore, an improved method of detecting SEE is proposed, and the method functionality is implemented in a circuit. Further, a sequence of experiments are carried out in the beam radiation terminal of the Heavy Ion Facility in Lanzhou (HIRFL), and a bunch of experimental data are collected. The irradiation tests were carried out using 129 Xe for the SEE research of 65 nm SRAMs; Using 12 C for the SEE research of the 65, 130 and 150 nm SRAMs with ECC module; Using 129 Xe for the SEL research of the common commercial SRAMs and so on. These experiments provide a statistical evidence of the effectiveness and robustness of the improved system. It is believed that the proposed system will be beneficial for detecting SEE in diverse settings, and it could be taken advantage of as a platform for future research on SEE tests in more intricate devices. (authors)

  18. The impact of climatic and seismic events on the short-term evolution of seacliffs based on 3-D mapping: Northern Monterey Bay, California

    Science.gov (United States)

    Hapke, C.; Richmond, B.

    2002-01-01

    Coastal cliff retreat along the central California coast is episodic, occurring in response to single large storms or seismic events. Traditional approaches to the study of long-term seacliff retreat utilize historical aerial photography and maps to delineate the landward migration of the top edge of the cliff over periods of tens of years to a century. While these methods yield cumulative retreat amounts, they provide little or no information on the character of the individual retreat events, nor the physical processes of retreat. This study addresses the processes of episodic and short-term coastal cliff retreat through the analysis of seacliff failure styles and retreat magnitudes. The study areas are three, 1-km-long sections of cliffed coast in northern Monterey Bay. The earliest data set is vertical aerial photography from October 18, 1989, taken the day following the magnitude 7.1 Loma Prieta earthquake. More recent photography, collected in late January, early February and early March of 1998, captured seacliff failure in response to the severe storms associated with the 1997-1998 El Nin??o. For each data set, high-resolution digital photogrammetric techniques are used to identify the top edge of the cliff. At each cliff failure location, its position, failure length and character are documented. Results suggest that on a regional scale, the seacliffs respond to seismic and climatic forcing differently. We have found variation in the magnitude of cliff response along the three sections of coast in the study area. Large-scale climatic events such as the 1997-1998 El Nin??o have a greater impact on both the linear extent of seacliff failure and the amount of cliff retreat.

  19. Automatic Event Detection and Picking of P, S Seismic Phases for Earthquake Early Warning: A Case Study of the 2008 Wenchuan Earthquake

    Science.gov (United States)

    WANG, Z.; Zhao, B.

    2015-12-01

    We develop an automatic seismic phase arrival detection and picking algorithm for the impending earthquakes occurred with diverse focal mechanisms and depths. The polarization analysis of the three-component seismograms is utilized to distinguish between P and S waves through a sliding time window. When applying the short term average/long term average (STA/LTA) method to the polarized data, we also construct a new characteristics function that can sensitively reflect the changes of signals' amplitude and frequency, providing a better detection for the phase arrival. Then an improved combination method of the higher order statistics and the Akaike information criteria (AIC) picker is applied to the refined signal to lock on the arrival time with a higher degree of accuracy. We test our techniques to the aftershocks of the Ms8.0 Wenchuan earthquake, where hundreds of three-component acceleration records with magnitudes of 4.0 to 6.4 are treated. In comparison to the analyst picks, the results of the proposed detection algorithms are shown to perform well and can be applied from a single instrument within a network of stations for the large seismic events in the Earthquake Early Warning System (EEWS).

  20. Joint Cross Well and Single Well Seismic Studies at Lost Hills, California

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, Roland; Daley, Thomas M.; Myer, Larry R.

    2002-06-25

    A series of time-lapse seismic cross well and single well experiments were conducted in a diatomite reservoir to monitor the injection of CO{sub 2} into a hydrofracture zone, based on P- and S-wave data. A high-frequency piezo-electric P-wave source and an orbital-vibrator S-wave source were used to generate waves that were recorded by hydrophones as well as three-component geophones. The injection well was located about 12 m from the source well. During the pre-injection phase water was injected into the hydrofrac-zone. The set of seismic experiments was repeated after a time interval of 7 months during which CO{sub 2} was injected into the hydrofractured zone. The questions to be answered ranged from the detectability of the geologic structure in the diatomic reservoir to the detectability of CO{sub 2} within the hydrofracture. Furthermore it was intended to determine which experiment (cross well or single well) is best suited to resolve these features. During the pre-injection experiment, the P-wave velocities exhibited relatively low values between 1700-1900 m/s, which decreased to 1600-1800 m/s during the post-injection phase (-5%). The analysis of the pre-injection S-wave data revealed slow S-wave velocities between 600-800 m/s, while the post-injection data revealed velocities between 500-700 m/s (-6%). These velocity estimates produced high Poisson ratios between 0.36 and 0.46 for this highly porous ({approx} 50%) material. Differencing post- and pre-injection data revealed an increase in Poisson ratio of up to 5%. Both, velocity and Poisson estimates indicate the dissolution of CO{sub 2} in the liquid phase of the reservoir accompanied by a pore-pressure increase. The single well data supported the findings of the cross well experiments. P- and S-wave velocities as well as Poisson ratios were comparable to the estimates of the cross well data. The cross well experiment did not detect the presence of the hydrofracture but appeared to be sensitive to overall

  1. Array analysis of the seismic wavefield of long-period events and volcanic tremor at Arenal volcano, Costa Rica

    Science.gov (United States)

    Almendros, Javier; Abella, Rafael; Mora, Mauricio M.; Lesage, Philippe

    2014-07-01

    We use wavefield decomposition methods (time domain cross correlation and frequency domain multiple-signal classification) to analyze seismic data recorded by a dense, small-aperture array located 2 km West of Arenal volcano, Costa Rica, and operated during 2.5 days. The recorded wavefield is dominated by harmonic tremor and includes also spasmodic tremor and long-period (LP) events. We find that the initial stages of LP events are characterized by three different wave arrivals. These arrivals propagate with similar back azimuths pointing to the volcano summit (˜80°N) and increasing apparent slowness of 0.4, 1.1, and 1.7 s/km. Spasmodic tremors cannot be regarded as coherent signals. On the contrary, harmonic tremors are highly coherent, characterized by the stability of the apparent slowness vector estimates. Apparent slowness lays in the range 1-2 s/km. Back azimuths point in the general direction of the volcano but with a large variability (40-120°N). Nevertheless, there are long-term variations and evidences of multiple simultaneous components in the harmonic tremor wavefield. These observations suggest that LP events and tremor are generated in a shallow source area near the volcano summit, although they do not share exactly the same source region or source processes. The tremor source is located in the shallowest part of the plumbing system, beneath the lava crust. This dynamic region is subject to complex fluctuations of the physical conditions. Degassing events at different locations of this region might generate variable seismic radiation patterns. The effects of topography and heterogeneous shallow structure of the volcano may amplify these variations and produce the wide directional span observed for volcanic tremor. On the other hand, the LP source seems to be more repeatable. LP events are likely triggered by fragmentation of the fluid flow in a slightly deeper portion of the volcanic conduits.

  2. Formulating a Strategic Response Plan for a High-Risk Seismic Event in New York City

    Science.gov (United States)

    2013-03-01

    engineering-bureau/geotech- eng-repository/GDM_Ch-9_Seismic_Design.pdf. 26 “silty sands or sands and gravels capped or containing seams of impermeable ...Tunnels likewise vary in design and length. Materials surrounding the tunnel consist of cast-iron, concrete , or varying composite materials. The...structure types do (wood, steel, and reinforced concrete ). The New York City Area Consortium for Earthquake Loss Mitigation. http://www.dhses.ny.gov/oem

  3. Body and Surface Wave Modeling of Observed Seismic Events Part 1.

    Science.gov (United States)

    1987-05-11

    1977), Nakanishi et al. (1977), and Mantovani (1978) considered S., Stephens and Isacks (1977) considered the transverse component of S., and Cansi and...parallel to the strike of the Andes. They also observed conversion of Oceanic S, to L. in areas of crustal thickening. Isacks and Stephens (1975) also...Center for Seismic Studies P.O. box 51 1300 North 17th Street N-2007 Kjeller, NORWAY Suite 1450 Arlington, VA 22209-2308 Dr. Carl Newton Los Alamos

  4. Mine-induced seismicity at East-Rand proprietary mines

    CSIR Research Space (South Africa)

    Milev, AM

    1995-09-01

    Full Text Available Mining results in seismic activity of varying intensity, from small micro seismic events to larger seismic events, often associated with significant seismic induced damages. This work deals with the understanding of the present seismicity...

  5. SINGLE CHANNEL SEISMIC APPLICATION FOR GAS CHARGED SEDIMENT RECONNAISSANCE IN GEOHAZARD STUDY OF PORT CONSTRUCTION AT WETLAND AREA

    Directory of Open Access Journals (Sweden)

    Taufan Wiguna

    2016-10-01

    Full Text Available Gas charged sediment as a one of parameter for geohazard study in infrastructure especially in swamp area. Instability of sediment layer for exampel subsidence and landslide result in geohazard potention that caused by gas charged sediment. Seismic single channel can be used to identufy gas charged sediment location. Seabed morphology is collected from bathymetry and tidal survey. From seismic profile interpretation shows gas charged sediment indication in Line A and Line B. That indication emerged by presence of acoustic turbid zone and acoustic blanking. Line A and Line B location will be spotlight in next geotechnic port construction study.

  6. Performance of Earthquake Early Warning Systems during the Major Events of the 2016-2017 Central Italy Seismic Sequence.

    Science.gov (United States)

    Festa, G.; Picozzi, M.; Alessandro, C.; Colombelli, S.; Cattaneo, M.; Chiaraluce, L.; Elia, L.; Martino, C.; Marzorati, S.; Supino, M.; Zollo, A.

    2017-12-01

    Earthquake early warning systems (EEWS) are systems nowadays contributing to the seismic risk mitigation actions, both in terms of losses and societal resilience, by issuing an alert promptly after the earthquake origin and before the ground shaking impacts the targets to be protected. EEWS systems can be grouped in two main classes: network based and stand-alone systems. Network based EEWS make use of dense seismic networks surrounding the fault (e.g. Near Fault Observatory; NFO) generating the event. The rapid processing of the P-wave early portion allows for the location and magnitude estimation of the event then used to predict the shaking through ground motion prediction equations. Stand-alone systems instead analyze the early P-wave signal to predict the ground shaking carried by the late S or surface waves, through empirically calibrated scaling relationships, at the recording site itself. We compared the network-based (PRESTo, PRobabilistic and Evolutionary early warning SysTem, www.prestoews.org, Satriano et al., 2011) and the stand-alone (SAVE, on-Site-Alert-leVEl, Caruso et al., 2017) systems, by analyzing their performance during the 2016-2017 Central Italy sequence. We analyzed 9 earthquakes having magnitude 5.0 data telemetry.

  7. Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland

    Science.gov (United States)

    Walter, Fabian; Amundson, Jason M.; O'Neel, Shad; Truffer, Martin; Fahnestock, Mark; Fricker, Helen A.

    2012-01-01

    We investigated seismic signals generated during a large-scale, multiple iceberg calving event that occurred at Jakobshavn Isbræ, Greenland, on 21 August 2009. The event was recorded by a high-rate time-lapse camera and five broadband seismic stations located within a few hundred kilometers of the terminus. During the event two full-glacier-thickness icebergs calved from the grounded (or nearly grounded) terminus and immediately capsized; the second iceberg to calve was two to three times smaller than the first. The individual calving and capsize events were well-correlated with the radiation of low-frequency seismic signals (time integrated force histories) were considerably smaller than previously reported glacial earthquakes. We thus speculate that such earthquakes may be a common, if not pervasive, feature of all full-glacier-thickness calving events from grounded termini. Finally, a key result from our study is that waveform inversions performed on low-frequency, calving-generated seismic signals may have only limited ability to quantitatively estimate mass losses from calving. In particular, the choice of source time function has little impact on the inversion but dramatically changes the earthquake magnitude. Accordingly, in our analysis, it is unclear whether the smaller or larger of the two calving icebergs generated a larger seismic signal.

  8. Neural network approach to the prediction of seismic events based on low-frequency signal monitoring of the Kuril-Kamchatka and Japanese regions

    Directory of Open Access Journals (Sweden)

    Irina Popova

    2013-08-01

    Full Text Available Very-low-frequency/ low-frequency (VLF/LF sub-ionospheric radiowave monitoring has been widely used in recent years to analyze earthquake preparatory processes. The connection between earthquakes with M ≥5.5 and nighttime disturbances of signal amplitude and phase has been established. Thus, it is possible to use nighttime anomalies of VLF/LF signals as earthquake precursors. Here, we propose a method for estimation of the VLF/LF signal sensitivity to seismic processes using a neural network approach. We apply the error back-propagation technique based on a three-level perceptron to predict a seismic event. The back-propagation technique involves two main stages to solve the problem; namely, network training, and recognition (the prediction itself. To train a neural network, we first create a so-called ‘training set’. The ‘teacher’ specifies the correspondence between the chosen input and the output data. In the present case, a representative database includes both the LF data received over three years of monitoring at the station in Petropavlovsk-Kamchatsky (2005-2007, and the seismicity parameters of the Kuril-Kamchatka and Japanese regions. At the first stage, the neural network established the relationship between the characteristic features of the LF signal (the mean and dispersion of a phase and an amplitude at nighttime for a few days before a seismic event and the corresponding level of correlation with a seismic event, or the absence of a seismic event. For the second stage, the trained neural network was applied to predict seismic events from the LF data using twelve time intervals in 2004, 2005, 2006 and 2007. The results of the prediction are discussed.

  9. Development of Guidelines for Use of Proton Single-Event Test Data to Bound Single-Event Effect Susceptibility Due to Light Ions

    Data.gov (United States)

    National Aeronautics and Space Administration — Conventional methods for Single-Event Effects (SEE) Hardness Assurance have proven difficult to adapt to Explorer, Cubesat and other risk tolerant platforms with...

  10. Improvement of IDC/CTBTO Event Locations in Latin America and the Caribbean Using a Regional Seismic Travel Time Model

    Science.gov (United States)

    Given, J. W.; Guendel, F.

    2013-05-01

    The International Data Centre is a vital element of the Comprehensive Test Ban Treaty (CTBT) verification mechanism. The fundamental mission of the International Data Centre (IDC) is to collect, process, and analyze monitoring data and to present results as event bulletins to Member States. For the IDC and in particular for waveform technologies, a key measure of the quality of its products is the accuracy by which every detected event is located. Accurate event location is crucial for purposes of an On Site Inspection (OSI), which would confirm the conduct of a nuclear test. Thus it is important for the IDC monitoring and data analysis to adopt new processing algorithms that improve the accuracy of event location. Among them the development of new algorithms to compute regional seismic travel times through 3-dimensional models have greatly increased IDC's location precision, the reduction of computational time, allowing forward and inverse modeling of large data sets. One of these algorithms has been the Regional Seismic Travel Time model (RSTT) of Myers et al., (2011). The RSTT model is nominally a global model; however, it currently covers only North America and Eurasia in sufficient detail. It is the intention CTBTO's Provisional Technical Secretariat and the IDC to extend the RSTT model to other regions of the earth, e.g. Latin America-Caribbean, Africa and Asia. This is particularly important for the IDC location procedure, as there are regions of the earth for which crustal models are not well constrained. For this purpose IDC has launched a RSTT initiative. In May 2012, a technical meeting was held in Vienna under the auspices of the CTBTO. The purpose of this meeting was to invite National Data Centre experts as well as network operators from Africa, Europe, the Middle East, Asia, Australia, Latin and North America to discuss the context under which a project to extend the RSTT model would be implemented. A total of 41 participants from 32 Member States

  11. Use of waveform similarity to define planes of mining-induced seismic events

    CSIR Research Space (South Africa)

    Spottiswoode, SM

    1998-04-15

    Full Text Available ; Deichmann and Garcia- Fernandez, 1992). Groups of doublets can be called multiplets (Fremont and Malone, 1987; Moriya et al., 1996). In this paper we extend the doublet relative location procedure and introduce multiplet relocation using arrival... by SIMRAC under the project GAP033. We would like to thank Blyvooruitzicht Mine and R.J. Stewart for use of the seismic data. The au- thors thank N.C. Gay for his helpful review and discussions. References Deichmann, N., Garcia-Fernandez, M., 1992. Rupture...

  12. Body and Surface Wave Modeling of Observed Seismic Events Part 3.

    Science.gov (United States)

    1987-05-13

    of the Seismic Waves L. and R. across Australia, Nature, vol. 180, pp. 495, 1957. -116- Bollinger , G. A., Attenuation of the L. Phases and... Paris , FRANCE Reston, VA 22092 Dr. Pierre Hechler Dr. Frode Ringdal Societe Radiomana NTNF/NORSAR 27, Rue Claude Bernard P.O. Box 51 75005, Paris , FRANCE...5- I% ~~ ~ .P.. .P K *- ~~ ~ 6 ’*P K Ph. K Dr. G.A. Bollinger Dr. Nuawia Barazangi Department of Geological Sciences Geological Sciences Virginia

  13. Single event effects induced by 15.14 MeV/u 136Xe ions

    International Nuclear Information System (INIS)

    Hou Mingdong; Zhang Qingxiang; Liu Jie; Wang Zhiguang; Jin Yunfan; Zhu Zhiyong; Zhen Honglou; Liu Changlong; Chen Xiaoxi; Wei Xinguo; Zhang Lin; Fan Youcheng; Zhu Zhourong; Zhang Yiting

    2002-01-01

    Single event effects induced by 15.14 MeV/u 136 Xe ions in different batches of 32k x 8 bits static random access memory are studied. The incident angle dependences of the cross sections for single event upset and single event latch up are presented. The SEE cross sections are plotted versus energy loss instead of linear energy transfer value in sensitive region. The depth of sensitive volume and thickness of 'dead' layer above the sensitive volume are estimated

  14. U-Th dating of broken speleothems from Cacahuamilpa cave, Mexico: Are they recording past seismic events?

    Science.gov (United States)

    Méjean, Pauline; Garduño-Monroy, Victor-Hugo; Pinti, Daniele L.; Ghaleb, Bassam; Bouvier, Laura; Gomez-Vasconcelos, Martha G.; Tremblay, Alain

    2015-01-01

    Cacahuamilpa cave is one of the largest karst systems in Central Mexico. The cave contains numerous massive speleothems broken and fallen following oriented directions, damaged during cataclysmic geological events. One fallen and two broken speleothems were sampled in the Cacahuamilpa cave for dating the rupture event using measured U-Th disequilibrium ages. A total of eight small carbonate cores were drilled perpendicular and longitudinal to the rupture surface. Results showed three groups of ages (weighted average): 0.95 ± 0.02 ka, 28.8 ± 0.2 ka and 88.0 ± 0.7 ka. This indicates that the construction of the Cacahuamilpa karst system, for which no absolute ages existed before this study, initiated at least since Late Pleistocene. The first two groups of ages might be related to two distinct episodes of intense seismic activity. Calculated minimum horizontal ground acceleration and frequency values of the seismic events needed to create the rupture of the stalagmites dated at 0.95 ± 0.02 ka and 28.8 ± 0.2 ka range between 1.3 and 2.0 m s-2 and between 13.4 and 20.8 Hz, respectively. These parameters are compatible with earthquakes of magnitude equal or higher than 7 M, with an epicentral distance between 50 and 100 km from the Cacahuamilpa cave. The stalagmite rupture dated at 88.0 ± 0.7 ka might result from the invasion of the cave by one of the older lahars deposits of the nearby volcano Nevado del Toluca, and successively fell by gravity instability.

  15. An unsupervised learning algorithm: application to the discrimination of seismic events and quarry blasts in the vicinity of Istanbul

    Directory of Open Access Journals (Sweden)

    H. S. Kuyuk

    2011-01-01

    Full Text Available The results of the application of an unsupervised learning (neural network approach comprising a Self Organizing Map (SOM, to distinguish micro-earthquakes from quarry blasts in the vicinity of Istanbul, Turkey, are presented and discussed. The SOM is constructed as a neural classifier and complementary reliability estimator to distinguish seismic events, and was employed for varying map sizes. Input parameters consisting of frequency and time domain data (complexity, spectral ratio, S/P wave amplitude peak ratio and origin time of events extracted from the vertical components of digital seismograms were estimated as discriminants for 179 (1.8 < Md < 3.0 local events. The results show that complexity and amplitude peak ratio parameters of the observed velocity seismogram may suffice for a reliable discrimination, while origin time and spectral ratio were found to be fuzzy and misleading classifiers for this problem. The SOM discussed here achieved a discrimination reliability that could be employed routinely in observatory practice; however, about 6% of all events were classified as ambiguous cases. This approach was developed independently for this particular classification, but it could be applied to different earthquake regions.

  16. Data processing of natural and induced events recorded at the seismic station Ostrava-Kr¨¢sn¨¦ Pole (OKC

    Directory of Open Access Journals (Sweden)

    Nov¨¢k Josef

    2001-09-01

    Full Text Available The operation of the seismic station Ostrava-Kr¨¢sn¨¦ Pole (OKC (¦Õ = 49.8352¡ãN; ¦Ë = 18.1422¡ãE which is situated at present in an experimental gallery nearby the Ostrava planetarium started in the year 1983 being equiped initially by analogue instrumentation. Modernization of instrumentation at the station was aimed at the installation of a new digital data acquisition system and the respective software packages for data interpretation and transmission.Data acquisition system VISTEC is based on PC which enables continuous recording of three- component short-period and medium-period systems with the sampling frequency of 20 Hz. The basic advantage of the OS Linux adopted allows remote access (telnet and the possibility of the recorded data transmission (ftp. Possible troubles in the seismic station operation can be quickly detected (even automatically and all recorded data are with minimum delay on disposal. The use of the remote access makes possible also to change the parameters of measuring set-up. The standard form of output data allows the application of standard software packages for visualisation and evaluation. There are on disposal following formates: GSE2/CM6, GSE2/INT and MiniSEED. The output data sets can be compressed by a special procedure. For interactive interpretation od digital seismic data, software package EVENT developed in the Geophysical Institute AS CR and package WAVE developed in the Institute of Geonics AS CR are used.Experimental operation of digital seismographs at the station OKC confirmed justification of its incorporation into the seismic stations of the Czech national seismological network (CNSN. Based on the preliminary analysis of digital data it proved that following groups of seismic events are recorded: earthquakes, induced seismic events from Polish copper and coal mines, induced seismic events from the Ostrava-Karvin¨¢ Coal Basin, quarry blasts and weak regional seismic events of the

  17. Estimation of parameters of finite seismic source model for selected event of West Bohemia year 2008 seismic swarm-methodology improvement and data extension

    Czech Academy of Sciences Publication Activity Database

    Kolář, Petr

    2015-01-01

    Roč. 19, č. 4 (2015), s. 935-947 ISSN 1383-4649 Institutional support: RVO:67985530 Keywords : West Bohemia 2008 seismic swarm * finite seismic source * stopping phases Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.550, year: 2015

  18. 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

  19. Mud volcano monitoring and seismic events along the North Anatolian Fault (Sea of Marmara)

    Science.gov (United States)

    Javad Fallahi, Mohammad; Lupi, Matteo; Mazzini, Adriano; Polonia, Alina; D'Alessandro, Antonino; D'Anna, Giuseppe; Gasperini, Luca

    2017-04-01

    The Sea of Marmara, a pull-apart basin formed along the northern strand of the North Anatolian Fault (NAF) system, is considered a seismic gap, that will be filled in the next decades by a large magnitude (M>7) earthquake, close to the Istanbul Metropolitan area (12 million inhabitants). For this reason, several marine geological and geophysical studies have been carried out in this region, starting from the destructive 1999 Mw 7.4 Izmit earthquake, to gather information relative to seismogenic potential of major fault strands. Together with these studies, in the frame of EC projects (i.e., MarmESONET and Marsite, among others), an intensive program of long-term monitoring of seismogenic faults was carried out using seafloor observatories deployed during several expeditions led by Italian, French and Turkish groups. These expeditions included MARM2013, on board of the R/V Urania, of the Italian CNR, when four ocean bottom seismometers (OBS) were deployed in the central part of the Sea of Marmara, at depths between 550 and 1000 m. One of the main aims of the experiment was to assess the long-term seismic activity along an active segment of the NAF, which connects the central and the western basins (depocenters), where the principal deformation zone appears relatively narrow and almost purely strike-slip. The present study shows the results of processing and analysis of continuous data records from these OBS stations during 50 days. We were able to detect seismic signal produced by an active mud volcano located close to the NAF trace, from about 3 to 6 km of distance from the OBS stations. Additionally, we captured the May 24, 2014, Mw 6.9 strike-slip earthquake occurred in the northern Aegean Sea between Greece and Turkey, which caused serious damage on the Turkish island of Imbros and the cities of Edirne and Çanakkale, as well as on the Greek island of Lemnos. The earthquake nucleated on the westward continuation of the NAF system in the NE Aegean Sea, and was

  20. Real-time monitoring of seismicity and deformation during the Bárdarbunga rifting event and associated caldera subsidence

    Science.gov (United States)

    Jónsdóttir, Kristín; Ófeigsson, Benedikt; Vogfjörd, Kristín; Roberts, Matthew; Barsotti, Sara; Gudmundsson, Gunnar; Hensch, Martin; Bergsson, Bergur; Kjartansson, vilhjálmur; Erlendsson, Pálmi; Friðriksdóttir, Hildur; Hreinsdóttir, Sigrún; Guðmundsson, Magnús; Sigmundsson, Freysteinn; Árnadóttir, Thóra; Heimisson, Elías; Hjorleifsdóttir, Vala; Soring, Jón; Björnsson, Bogi; Oddsson, Björn

    2015-04-01

    We present a monitoring overview of a rifting event and associated caldera subsidence in a glaciated environment during the Bárðarbunga volcanic crisis. Following a slight increase in seismicity and a weak deformation signal, noticed a few months before the unrest by the SIL monitoring team, an intense seismic swarm began in the subglacial Bárðarbunga caldera on August 16 2014. During the following two weeks, a dyke intruded into the crust beneath the Vatnajökull ice cap, propagating 48 km from the caldera to the east-north-east and north of the glacier where an effusive eruption started in Holuhraun. The eruption is still ongoing at the time of writing and has become the largest eruption in over 200 years in Iceland. The dyke propagation was episodic with a variable rate and on several occasions low frequency seismic tremor was observed. Four ice cauldrons, manifestations of small subglacial eruptions, were detected. Soon after the swarm began the 7x11 km wide caldera started to subside and is still subsiding (although at slower rates) and has in total subsided over 60 meters. Unrest in subglacial volcanoes always calls for interdisciplinary efforts and teamwork plays a key role for efficient monitoring. Iceland has experienced six subglacial volcanic crises since modern digital monitoring started in the early 90s. With every crisis the monitoring capabilities, data interpretations, communication and information dissemination procedures have improved. The Civil Protection calls for a board of experts and scientists (Civil Protection Science Board, CPSB) to share their knowledge and provide up-to-date information on the current status of the volcano, the relevant hazards and most likely scenarios. The evolution of the rifting was monitored in real-time by the joint interpretation of seismic and cGPS data. The dyke propagation could be tracked and new, updated models of the dyke volume were presented at the CPSB meetings, often daily. In addition, deformation

  1. Extent of slow slip events in the Guerrero seismic gap (Mexico): observations from space-borne SAR interferometry

    Science.gov (United States)

    Pathier, E.; Bacques, G.; Doin, M.; Cavalié, O.; Radiguet, M.; Lasserre, C.; Cotte, N.; Walpersdorf, A.

    2013-12-01

    Since 1998, four slow slip events (SSEs) have been recorded by geodesy in the Guerrero state of Mexico. They occurred on the subduction interface where the Coco plate subducts at about 6 cm/year beneath the North-America plate. SSEs spatially overlap the seismic gap of Guerrero which is a 100km-long portion of the Mexican subduction zone where no significant earthquakes have occurred since 1911. This duration contrasts with the average recurrence time of 30-60 years for large subduction earthquakes observed along the Mexican subduction zone (Nishenko and Singh, 1987a). To the west, the gap is limited by the slip distribution of the 1979 (M=7.6) and the 1985 (M=8.1) earthquakes, and to the east by the 1957 (M=7.8) and 1962 Acapulco events (M=7 and 7.1). An important issue is to know whether SSEs penetrate into the seismogenic zone and whether they are restricted to the seismic gap or have a larger extent. Radiguet et al, (2012) studied three SSEs that occurred in 2002, 2006 and 2009-2010, based on continuous GPS data. They show that SSEs have variable lateral extents, with significant slip within the 100km-long seismic gap, but also occurring on a wider area with a 250 km lateral extension when considering slip downdip the seismogenic zone (estimated to end at about 25km depth according to Suarez et al, 1990). Within the gap, results from Radiguet et al. suggest also that SSE can propagate shallower than the 25 km limit and that, west of the gap, the aseismic slip overlaps the 1979 and the 1985 earthquakes coseismic slip distribution. However, the GPS network design used in their analysis is mainly composed of two perpendicular profiles: a profile along the coast and a profile perpendicular to the coast from Acapulco to Mexico. Away from these profiles the resolution of the SSE location decreases rapidly, which limits the analysis of SSE extents. Here, we used space-borne SAR interferometry (InSAR) to overcome this limitation. Despite atmospheric and decorrelation

  2. WOOD-BASED SOLUTIONS TO IMPROVE QUALITY AND SAFETY AGAINST SEISMIC EVENTS IN CONSERVATION OF HISTORICAL BUILDINGS

    Directory of Open Access Journals (Sweden)

    Elena Ongaretto

    2016-03-01

    Full Text Available Historical buildings can be highly vulnerable to earthquakes if in-plane strength and stiffness of floors and roofs are not sufficient to limit out-of-plane deformation of walls and to transmit the seismic forces among walls efficiently. In fact, floors and roofs in existing masonry buildings are normally realized with timber beams, purlins and a single layer of timber boards, and their in-plane stiffness can be limited when subjected to shear forces. Various retrofitting techniques are available, whose effectiveness can be very different and not easily predictable theoretically. In this paper, the behavior of different strengthening criteria for historical buildings, involving the use of wood and wood based products, is illustrated and critically discussed. Code provisions, design rules and calculation methods for strengthening interventions are described. In-plane behavior of floor and roof structures and their interaction and connection to the seismic resistant wall systems are considered. Finally, a case study of restoration intervention on a historic barn is presented, which was damaged during the 2012 earthquake in Emilia. The illustration is focused on the improvement of the whole safety of the construction by means of specifically designed interventions on the wooden roof.

  3. Cosmic and terrestrial single-event radiation effects in dynamic random access memories

    International Nuclear Information System (INIS)

    Massengill, L.W.

    1996-01-01

    A review of the literature on single-event radiation effects (SEE) on MOS integrated-circuit dynamic random access memories (DRAM's) is presented. The sources of single-event (SE) radiation particles, causes of circuit information loss, experimental observations of SE information upset, technological developments for error mitigation, and relationships of developmental trends to SE vulnerability are discussed

  4. Single-well moment tensor inversion of tensile microseismic events

    Czech Academy of Sciences Publication Activity Database

    Grechka, V.; Li, Z.; Howell, B.; Vavryčuk, Václav

    2016-01-01

    Roč. 81, č. 6 (2016), KS219-KS229 ISSN 0016-8033 R&D Projects: GA ČR(CZ) GAP210/12/1491; GA ČR(CZ) GC16-19751J Institutional support: RVO:67985530 Keywords : microseismic events * moment tensor inversion * mathematical formulation Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.391, year: 2016

  5. Single item inventory models : A time- and event- averages approach

    NARCIS (Netherlands)

    E.M. Bazsa-Oldenkamp; P. den Iseger

    2003-01-01

    textabstractThis paper extends a fundamental result about single-item inventory systems. This approach allows more general performance measures, demand processes and order policies, and leads to easier analysis and implementation, than prior research. We obtain closed form expressions for the

  6. Characterization of induced seismicity patterns derived from internal structure in event clusters

    Science.gov (United States)

    Goertz-Allmann, B. P.; Gibbons, S. J.; Oye, V.; Bauer, R.; Will, R.

    2017-05-01

    microseismicity induced by CO2 injection at Decatur, Illinois, occurs in distinct clusters and shows no obvious correlation with the proceeding pressure front. We analyze some of these clusters in more depth by using a waveform cross-correlation approach. With this approach we can associate about 1400 events from two clusters, with moment magnitudes between 1.1 and -1.7, with specific formations of much smaller vertical dimensions (tens of meters) than the depth resolution of traveltime-based event locations. The differentiation of reservoir and basement events, and the definition of subclusters by waveform correlation, rather than by location, helps to better analyze the spatiotemporal evolution of the events within a cluster. In the Decatur case, this is characterized by event migration from the reservoir into the adjacent basement. The spatial variation of Brune stress drop and Gutenberg b value exhibits signs of a fluid-driven triggering mechanism at the cluster level, revealing a punctual hydraulic connection between reservoir and basement, most likely associated with basement faults cutting into the reservoir. The observed clustering of microseismicity can thus be explained by the lateral heterogeneity of permeability and crustal strength and is overall consistent with a pressure-induced triggering mechanism. Hence, proper long-term risk mitigation for large-scale fluid injection close to the basement requires prior mapping of small subseismic basement-connected faults.

  7. Social Media and E-Learning in Response to Seismic Events: Resilient Practices

    Science.gov (United States)

    Tull, Susan; Dabner, Nicki; Ayebi-Arthur, Kofi

    2017-01-01

    The motivation to adopt innovative communication and e-learning practices in education settings can be stimulated by events such as natural disasters. Education institutions in the Pacific Rim cannot avoid the likelihood of natural disasters that could close one or more buildings on a campus and affect their ability to continue current educational…

  8. Robust satellite techniques (RST for the thermal monitoring of earthquake prone areas: the case of Umbria-Marche October, 1997 seismic events

    Directory of Open Access Journals (Sweden)

    V. Tramutoli

    2008-06-01

    Full Text Available Several authors claim a space-time correlation between increases in Earth’s emitted Thermal Infra-Red (TIR radiation and earthquake occurrence. The main problems of such studies regard data analysis and interpretation, which are often done without a validation/confutation control. In this context, a robust data analysis technique (RST, i.e. Robust Satellite Techniques is proposed which permits a statistically based definition of TIR «anomaly » and uses a validation/confutation approach. This technique was already applied to satellite TIR surveys in seismic regions for about twenty earthquakes that occurred in the world. In this work RST is applied for the first time to a time sequence of seismic events. Nine years of Meteosat TIR observations have been analyzed to characterize the unperturbed TIR signal behaviour at specific observation times and locations. The main seismic events of the October 1997 Umbria-Marche sequence have been considered for validation, and relatively unperturbed periods (no earthquakes with Mb ? 4 were taken for confutation purposes. Positive time-space persistent TIR anomalies were observed during seismic periods, generally overlapping the principal tectonic lineaments of the region and sometimes focusing on the vicinity of the epicentre. No similar (in terms of relative intensity and space-time persistence TIR anomalies were detected during seismically unperturbed periods.

  9. Determination of elastic bearing capacity limits for additional seismic events. Annex 1. Data on seismic input and dynamic load calculations. Ermittlung elastischer Grenztragbereiche unter dem Zusatzlastfall Erdbeben. Anhang 1. Zusammenstellung des Seismischen Inputs und der dynamischen Rechnungen

    Energy Technology Data Exchange (ETDEWEB)

    Buchhardt, F.; Matthees, W.; Magiera, G.; Mathiak, F.

    1986-12-01

    In the Federal Republic of Germany KTA rule 2201 in the valid version 6/75 being the basis for the design of nuclear power plants against seismic events is now under discussion for revisions. One of the main demands to modify KTA rule 2201 consists in cancelling the existing design philosophy, i.e. design against an operating basis earthquake (AEB) as well as against a safe shutdown earthquake (SEB) in order to only design against the safe shutdown earthquake. It is the scope of this study to quantify by comprehensive, parametric analyses so-called 'elastic bearing capacity limit margins' for seismic events; hereby different seismic input criteria - conventional as well as recently proposed - are taken into account to investigate the influence of eventual modifications in seismic design philosophy. This way a relation between AEB and SEB has to be defined so that SEB is just still predominant for the design while AEB still will yield to elastic behaviour. The study covers all German site conditions.

  10. Identification of rock mass discontinuities in a cluster of seismic event hypocenters.

    CSIR Research Space (South Africa)

    Kijko, A

    1999-01-01

    Full Text Available cluster is obtained. This simplified pattern might then be interpreted in terms of a fault, a system of faults or in general, as a rock mass discontinuity. The process is tested and demonstrated for three synthetic sets of data: a single fault, two joined...

  11. Intercalation events visualized in single microcrystals of graphite.

    Science.gov (United States)

    White, Edward R; Lodico, Jared J; Regan, B C

    2017-12-06

    The electrochemical intercalation of layered materials, particularly graphite, is fundamental to the operation of rechargeable energy-storage devices such as the lithium-ion battery and the carbon-enhanced lead-acid battery. Intercalation is thought to proceed in discrete stages, where each stage represents a specific structure and stoichiometry of the intercalant relative to the host. However, the three-dimensional structures of the stages between unintercalated and fully intercalated are not known, and the dynamics of the transitions between stages are not understood. Using optical and scanning transmission electron microscopy, we video the intercalation of single microcrystals of graphite in concentrated sulfuric acid. Here we find that intercalation charge transfer proceeds through highly variable current pulses that, although directly associated with structural changes, do not match the expectations of the classical theories. Evidently random nanoscopic defects dominate the dynamics of intercalation.

  12. The forecast of mining-induced seismicity and the consequent risk of damage to the excavation in the area of seismic event

    Directory of Open Access Journals (Sweden)

    Jan Drzewiecki

    2017-01-01

    Full Text Available The Central Mining Institute has developed a method for forecasting the amount of seismic energy created by tremors induced by mining operations. The results of geophysical measurements of S wave velocity anomalies in a rock mass or the results of analytic calculations of the values of pressure on the horizon of the elastic layers are used in the process of calculating the energy. The calculation program which has been developed and adopted has been modified over recent years and it now enables not only the prediction of the energy of dynamic phenomena induced by mining but also the forecasting of the devastating range of seismic shock. The results obtained from this calculation, usually presented in a more readable graphic form, are useful for the macroscopic evaluation of locations that are potential sources of seismic energy. Forecasting of the maximum energy of seismic shock without prior knowledge of the location of the shock's source, does not allow shock attenuation that results from, for example, a distance of tremor source from the excavation which will be affected by seismic energy, to be taken into consideration. The phenomena of energy dissipation, which is taken into account in the forecasts, create a new quality of assessment of threat to the excavation. The paper presents the principle of a method of forecasting the seismic energy of a shock and the risk of damage to the excavation as a result of the impact of its energy wave. The solution assumes that the source of the energy shock is a resilient layer in which the sum of the gravitational stresses, resulting from natural disturbances and those induced by the conducted or planned mining exploitation, is estimated. The proposed solution assumes a spherical model for the tremor source, for which seismic energy is forecasted as a function of the longwall advance and the elementary value of seismic energy destroying the excavation. Subsequently, the following are calculated for the

  13. The risks to miners, mines, and the public posed by large seismic events in the gold mining districts of South Africa

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2006-10-01

    Full Text Available of seismicity in their disaster management plans, and Johannesburg is urged to do likewise. Some buildings are considered vulnerable to damage by large seismic events, posing safety and financial risks. It is recommended that an earthquake engineer inspect..., to “inquire into and report on the origin and effect of the earth tremors experienced in the village of Ophirton”. The 1908 Committee found that “under the great weight of the superincumbent mass of rock … the pillars are severely strained; that ultimately...

  14. Single-Event Effects in Silicon and Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2014-01-01

    NASA Electronics Parts and Packaging program-funded activities over the past year on single-event effects in silicon and silicon carbide power devices are presented, with focus on SiC device failure signatures.

  15. Current Single Event Effects Results for Candidate Spacecraft Electronics for NASA

    Science.gov (United States)

    OBryan, Martha V.; Seidleck, Christina M.; Carts, Martin A.; LaBel, Kenneth A.; Marshall, Cheryl J.; Reed, Robert A.; Sanders, Anthony B.; Hawkins, Donald K.; Cox, Stephen R.; Kniffin, Scott D.

    2004-01-01

    We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects. Devices tested include digital, analog, linear bipolar, and hybrid devices, among others.

  16. Development of Cost-Effective Screening Techniques to Assess Single-Event Latchup Susceptibility

    Data.gov (United States)

    National Aeronautics and Space Administration — Although Single-Event Latchup (SEL) has proven to be one of the most significant radiation threats for low-cost missions, conventional SEL hardness assurance...

  17. Single-event upset and snapback in silicon-on-insulator devices

    International Nuclear Information System (INIS)

    Dodd, Paul E.; Shaneyfelt, Marty R.; Schwank, James R.; Hash, Gerald L.; Draper, Bruce L.; Winokur, Peter S.

    2000-01-01

    SEU is studied in SOI transistors and circuits with various body tie structures. The importance of impact ionization effects, including single-event snapback, is explored. Implications for hardness assurance testing of SOI integrated circuits are discussed

  18. Global study of great (M>= 7) deep focus seismic events having regard to the May 24, 2013 Mw 8.3 earthquake the Sea of Okhotsk, Russia

    Science.gov (United States)

    Varga, Peter; Rogozhin, Evgeny; Süle, Bálint; Andreeva, Nadezda

    2014-05-01

    Distribution of great seismic events M >= 7.0 and consequently the released seismic energy along the Earth radius is of bimodal character. 90% of the great seismic events, which are responsible for the most of energy released, occur relatively close to the Earth's surface, at an average depth of 50 km. The vast majority of remaining 10% is associated with seismic events that occur very deep, an average of 580-590 km, above the border between transition zone and lower mantle (660 km). These very deep earthquakes (depth >= 500 km) differ significantly from the shallow events. For the study of the distribution of M >= 7.0 earthquakes and their radiated energy a catalogue was completed for the time-interval between 1900 and 2013. Examination of the source zones in which both shallow and deep M >= 7.0 earthquakes occur shows that linear distribution of deep earthquakes is considerably shorter than that found for the shallow earthquakes, which determine the length of the zone. The position of very deep (≥ 500 km) earthquakes foci show where the down going lithosperic plates conflict with the upper boundary of lower mantle, and where they probably cross it. This passage generates compression - elongation inside the slab. A comparison of temporal distribution of shallow and deep seismic events of a given source zone suggests that there is no direct relationship in the distribution of these two different earthquake activities. The largest of these great deep earthquakes, the May 24, 2013 Mw 8.3 earthquake the Sea of Okhotsk, was preceded by an earthquake swarm, which consists 58 M >= 5 events and occurred between May 15 and 24, 2013 in the higher part of the sinking slab east of Kamchatka. The aftershock activity after the Okhotsk Sea earthquake was moderate: twelve events with magnitudes above M 4 were observed till June 27. These events determine a fault area (2.64x104 km2) similar to the case of a shallow M 8.3 event. The effect of Okhotsk Sea was felt throughout

  19. Single event monitoring system based on Java 3D and XML data binding

    International Nuclear Information System (INIS)

    Wang Liang; Chinese Academy of Sciences, Beijing; Zhu Kejun; Zhao Jingwei

    2007-01-01

    Online single event monitoring is important to BESIII DAQ System. Java3D is extension of Java Language in 3D technology, XML data binding is more efficient to handle XML document than SAX and DOM. This paper mainly introduce the implementation of BESIII single event monitoring system with Java3D and XML data binding, and interface for track fitting software with JNI technology. (authors)

  20. Pulsed laser simulation of VLSI single-event effect testing study

    International Nuclear Information System (INIS)

    Xue Yuxiong; Cao Zhou Yang Shiyu; Tian Kai; Liu Shufen; Chu Nan; Cao Haining; Shang Zhi

    2008-01-01

    This paper describes a study aimed at investigating the pulsed laser simulation of Single-Event Effect (SEE) testing for VLSI Intel386EX CPU, using our laboratory LSS (laser simulation system). We have detailed SEE testing principle, testing method, testing system constituting, testing result. It validates that our laser pulses simulate may use SEE testing in VLSI, and Intel 386Ex have a large locking resistance to single event. (authors)

  1. NEPP Update of Independent Single Event Upset Field Programmable Gate Array Testing

    Science.gov (United States)

    Berg, Melanie; Label, Kenneth; Campola, Michael; Pellish, Jonathan

    2017-01-01

    This presentation provides a NASA Electronic Parts and Packaging (NEPP) Program update of independent Single Event Upset (SEU) Field Programmable Gate Array (FPGA) testing including FPGA test guidelines, Microsemi RTG4 heavy-ion results, Xilinx Kintex-UltraScale heavy-ion results, Xilinx UltraScale+ single event effect (SEE) test plans, development of a new methodology for characterizing SEU system response, and NEPP involvement with FPGA security and trust.

  2. A meteor shockwave event recorded at seismic and infrasound stations in northern Taiwan

    Science.gov (United States)

    Kumar, Utpal; Chao, Benjamin F.; Hsieh, Yikai; Chang, Emmy T. Y.

    2017-12-01

    Three mysterious explosion sounds were heard in the coastal towns of Tamsui, west of Taipei in northern Taiwan, in the early evening of December 5, 2013. The event left clear signals that are identified in the recordings of 12 regional seismometers and 3 infrasound sensors and processed by means of travel time analysis. The apparent velocity of 330 m/s of the signals confirms that the energy transmission was through the atmosphere, and the characteristics of the waveforms suggest the meteor-generated shockwaves. We use the graphical method as well as the Genetic Algorithm optimization approach to constrain the trajectory of the meteor and to locate its projected intercept with the ground—(25.33 N, 121.26 E), approximately 20 km off the coast of Tamsui. The trajectory has azimuth (measured from north in a map view in the clockwise direction) of 303° and (near-vertical) elevation angle of 70°. From the observed period of 1.3 s at the maximum amplitude of the infrasound signal, we estimate by conventional scaling law that the meteor in question had impact energy on the order of 5 × 1010 J (equivalent to an earthquake of local magnitude 4) or roughly a size of 0.5 m across.

  3. MULTITEMPORAL 3D MODELLING FOR CULTURAL HERITAGE EMERGENCY DURING SEISMIC EVENTS: DAMAGE ASSESMENT OF S. AGOSTINO CHURCH IN AMATRICE (RI

    Directory of Open Access Journals (Sweden)

    F. Chiabrando

    2017-05-01

    Full Text Available One of the challenging purposes that must be undertaken by applied geomatics, is the need of monitoring by documenting continuously over time the evolution of urban spaces. Nowadays, this is a subject of great interest and study, mainly in case of sudden emergency events that implicate urban areas and specific historical buildings of our heritage. The newest Geomatics technique solutions must enable the demands of damage documentation, risk assessment, management and data sharing as efficiently as possible, in relation to the danger condition, to the accessibility constraints of areas and to the tight deadlines needs. In August 24th 2016, the first earthquake hit the area of central Italy with a magnitude of 6.0; since then, the earth never stop shaking in a wide area in the middle of Italy. On 26th and 30th of October, two other big seismic events were recorded (magnitude 5.9 and 6.5 and the already damaged built heritage were struck again. Since the beginning of the emergency all the available resources (human and material were deployed and the world of researchers is trying to furnish an effective contribute as well. Politecnico di Torino, in coordination with the national institutions, is deploying people, expertise and resources. The geomatics research group and the connected Disaster Recovery team (DIRECT - http://areeweb.polito.it/direct/ is part of this process and is working in deep contact and collaboration with the Remotely Piloted Aircraft Systems (RPAS group of the Italian Firefighter. Starting from the first earthquake the late medieval religious complex of S. Agostino has been carefully monitored and detected, using a multi-perspective oblique imagery strategy with the aim to achieve 3D aerial and terrestrial models, in a multi-temporal perspective concerning three different time situation.

  4. Multitemporal 3d Modelling for Cultural Heritage Emergency during Seismic Events: Damage Assesment of S. Agostino Church in Amatrice (ri)

    Science.gov (United States)

    Chiabrando, F.; Di Lolli, A.; Patrucco, G.; Spanò, A.; Sammartano, G.; Teppati Losè, L.

    2017-05-01

    One of the challenging purposes that must be undertaken by applied geomatics, is the need of monitoring by documenting continuously over time the evolution of urban spaces. Nowadays, this is a subject of great interest and study, mainly in case of sudden emergency events that implicate urban areas and specific historical buildings of our heritage. The newest Geomatics technique solutions must enable the demands of damage documentation, risk assessment, management and data sharing as efficiently as possible, in relation to the danger condition, to the accessibility constraints of areas and to the tight deadlines needs. In August 24th 2016, the first earthquake hit the area of central Italy with a magnitude of 6.0; since then, the earth never stop shaking in a wide area in the middle of Italy. On 26th and 30th of October, two other big seismic events were recorded (magnitude 5.9 and 6.5) and the already damaged built heritage were struck again. Since the beginning of the emergency all the available resources (human and material) were deployed and the world of researchers is trying to furnish an effective contribute as well. Politecnico di Torino, in coordination with the national institutions, is deploying people, expertise and resources. The geomatics research group and the connected Disaster Recovery team (DIRECT - http://areeweb.polito.it/direct/) is part of this process and is working in deep contact and collaboration with the Remotely Piloted Aircraft Systems (RPAS) group of the Italian Firefighter. Starting from the first earthquake the late medieval religious complex of S. Agostino has been carefully monitored and detected, using a multi-perspective oblique imagery strategy with the aim to achieve 3D aerial and terrestrial models, in a multi-temporal perspective concerning three different time situation.

  5. A fast and robust method for moment tensor and depth determination of shallow seismic events in CTBT related studies.

    Science.gov (United States)

    Baker, Ben; Stachnik, Joshua; Rozhkov, Mikhail

    2017-04-01

    International Data Center is required to conduct expert technical analysis and special studies to improve event parameters and assist State Parties in identifying the source of specific event according to the protocol to the Protocol to the Comprehensive Nuclear Test Ban Treaty. Determination of seismic event source mechanism and its depth is closely related to these tasks. It is typically done through a strategic linearized inversion of the waveforms for a complete or subset of source parameters, or similarly defined grid search through precomputed Greens Functions created for particular source models. In this presentation we demonstrate preliminary results obtained with the latter approach from an improved software design. In this development we tried to be compliant with different modes of CTBT monitoring regime and cover wide range of source-receiver distances (regional to teleseismic), resolve shallow source depths, provide full moment tensor solution based on body and surface waves recordings, be fast to satisfy both on-demand studies and automatic processing and properly incorporate observed waveforms and any uncertainties a priori as well as accurately estimate posteriori uncertainties. Posterior distributions of moment tensor parameters show narrow peaks where a significant number of reliable surface wave observations are available. For earthquake examples, fault orientation (strike, dip, and rake) posterior distributions also provide results consistent with published catalogues. Inclusion of observations on horizontal components will provide further constraints. In addition, the calculation of teleseismic P wave Green's Functions are improved through prior analysis to determine an appropriate attenuation parameter for each source-receiver path. Implemented HDF5 based Green's Functions pre-packaging allows much greater flexibility in utilizing different software packages and methods for computation. Further additions will have the rapid use of Instaseis

  6. Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

    Science.gov (United States)

    Yin, A.; Yu, X.; Shen, Z.

    2014-12-01

    Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

  7. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

  8. Measurement of the top quark mass from single-top production events

    CERN Document Server

    CMS Collaboration

    2016-01-01

    We measure the mass of the top quark from events where a single top quark is produced. The analysis is performed on data from $\\mathrm{pp}$ collisions collected by the CMS detector at a center of mass energy of 8 TeV. The top quark is reconstructed from its decay $\\mathrm{t} \\rightarrow \\mathrm{W}^+ \\mathrm{b}$, with the $\\mathrm{W}$ boson decaying leptonically in the muon channel. Specific event topology and kinematic properties are used in order to enrich the sample in single-top-quark events in the t-channel, at the expense of top-quark pair production events. For the single-top quark component, a fit to the reconstructed top invariant mass distribution yields $m_{\\mathrm{t}}=172.60 \\pm 0.77~\\mathrm{(stat)}~^{+0.97}_{-0.93}~\\mathrm{(syst)}$ GeV.

  9. Method and apparatus for single-stepping coherence events in a multiprocessor system under software control

    Science.gov (United States)

    Blumrich, Matthias A.; Salapura, Valentina

    2010-11-02

    An apparatus and method are disclosed for single-stepping coherence events in a multiprocessor system under software control in order to monitor the behavior of a memory coherence mechanism. Single-stepping coherence events in a multiprocessor system is made possible by adding one or more step registers. By accessing these step registers, one or more coherence requests are processed by the multiprocessor system. The step registers determine if the snoop unit will operate by proceeding in a normal execution mode, or operate in a single-step mode.

  10. Single-Event Transgene Product Levels Predict Levels in Genetically Modified Breeding Stacks.

    Science.gov (United States)

    Gampala, Satyalinga Srinivas; Fast, Brandon J; Richey, Kimberly A; Gao, Zhifang; Hill, Ryan; Wulfkuhle, Bryant; Shan, Guomin; Bradfisch, Greg A; Herman, Rod A

    2017-09-13

    The concentration of transgene products (proteins and double-stranded RNA) in genetically modified (GM) crop tissues is measured to support food, feed, and environmental risk assessments. Measurement of transgene product concentrations in breeding stacks of previously assessed and approved GM events is required by many regulatory authorities to evaluate unexpected transgene interactions that might affect expression. Research was conducted to determine how well concentrations of transgene products in single GM events predict levels in breeding stacks composed of these events. The concentrations of transgene products were compared between GM maize, soybean, and cotton breeding stacks (MON-87427 × MON-89034 × DAS-Ø15Ø7-1 × MON-87411 × DAS-59122-7 × DAS-40278-9 corn, DAS-81419-2 × DAS-44406-6 soybean, and DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 × MON-88913-8 × DAS-81910-7 cotton) and their component single events (MON-87427, MON-89034, DAS-Ø15Ø7-1, MON-87411, DAS-59122-7, and DAS-40278-9 corn, DAS-81419-2, and DAS-44406-6 soybean, and DAS-21023-5, DAS-24236-5, SYN-IR102-7, MON-88913-8, and DAS-81910-7 cotton). Comparisons were made within a crop and transgene product across plant tissue types and were also made across transgene products in each breeding stack for grain/seed. Scatter plots were generated comparing expression in the stacks to their component events, and the percent of variability accounted for by the line of identity (y = x) was calculated (coefficient of identity, I 2 ). Results support transgene concentrations in single events predicting similar concentrations in breeding stacks containing the single events. Therefore, food, feed, and environmental risk assessments based on concentrations of transgene products in single GM events are generally applicable to breeding stacks composed of these events.

  11. Seismic response to power production at the Coso Geothermal field, south-eastern CA: using operational parameters and relocated events to study anthropogenic seismicity rates and reservoir scale tectonic structure

    Science.gov (United States)

    Lajoie, L. J.; O'Connell, D. R.; Creed, R. J.; Brodsky, E. E.

    2013-12-01

    use Bayesian S-wave picking of Coso borehole network microearthquake data and fully-nonlinear 3D hypocenter grid searches to obtain 18000+ well located hypocenters in the geothermal field. Coso geothermal seismicity is not diffuse; 87% of all the Coso geothermal hypocenters from 1996-2008 occur within 25 m of planes consistent with tectonic processes along the eastern California shear zone. 83% of the hypocenters associate with vertical and steeply-dipping conjugate N-NW dextral and NE sinistral strike slip planes, 12% of the earthquakes on normal-slip planes with dips of 35-70 degrees, and 5% of the events with reverse-oblique-slip on steeply-dipping planes. The non-diffuse nature of seismicity suggests that induced events occur preferentially on pre-existing structures and that flow is concentrated in fractures. With minimum horizontal stress oriented at 81 degrees, and no normal faults, in the western part of the field, and minimum horizontal stress of 106 degrees and pervasive normal faults in the eastern portion of the field (Roquemore, 1980; Blake and Davatzes, 2006), structures that are favorably oriented in the current stress field appear to be most commonly activated by geothermal operations.

  12. Investigation of the Semicoa 2N7616 and 2N7425 and the Microsemi 2N7480 for Single-Event Gate Rupture and Single-Event Burnout

    Science.gov (United States)

    Scheick, Leif

    2014-01-01

    Single-event-effect test results for hi-rel total-dose-hardened power MOSFETs are presented in this report. The 2N7616 and the 2N7425 from Semicoa and the 2N7480 from International Rectifier were tested to NASA test condition standards and requirements. The 2N7480 performed well and the data agree with the manufacture's data. The 2N7616 and 2N7425 were entry parts from Semicoa using a new device architecture. Unfortunately, the device performed poorly and Semicoa is withdrawing power MOSFETs from it line due to these data. Vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) are the most commonly used power transistor. MOSFETs are typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single-event gate rupture (SEGR) or single-event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. See [1] through [5] for more information. The objective of this effort was to investigate the SEGR and SEB responses of two power MOSFETs recently produced. These tests will serve as a limited verification of these parts. It is acknowledged that further testing on the respective parts may be needed for some mission profiles.

  13. Soil-structural interaction analysis of RBMK type NPP for seismic event. Progress report. From 1 July 1998 - 30 June 1999

    International Nuclear Information System (INIS)

    1999-01-01

    The objective of the project is to assess the structural behavior and safety capacity of a RBMK-1000 MW Main Building Complex under critical combination of loads including seismic events. This project is part of the Coordinated Research Program carried out by International Atomic Energy Agency on safety of RBMK Type Nuclear Power Plants (NPP) in Relation to External Events. The nuclear power plant considered for this study is the Sosnovy Bor NPP, located near St.Petersburg, Russia. The Soviet standard design RBMK-1000 MW type units installed in Sosnovy Bor NPP were originally designed for a Safe Shutdown Earthquake (SSE) with a peak ground acceleration (PGA) of 0.1 g. The relevant response spectra are not available for reference and assessment. The new international requirements for nuclear power plants in operation require site specific seismic hazard studies as a basis for the definition of a Review Level Earthquake (RLE) for reassessment of the structures and safety related equipment Ell - As the RLE site specific seismic data is still not available, the RLE earthquake spectra for Kozloduy NPP scaled to PGA=0.1 g were used in this study. This value is intentionally chosen for comparison purposes. The Russian design requirements (if design floor response spectra are available) will be compared with the international regulations. The scope of the study is to perform a Soil-Structure Interaction (SSI) seismic response analysis of the referenced RBMK-11000 MW. Main Building Complex to evaluate the effect on the structural response of a greater than design earthquake. The analysis is focused on a realistic assessment of the structural response to a potentially higher earthquake level instead of a conservative design type analysis. Special attention is paid on the seismic response of the sub-structures in the safe shutdown path, as well as on the locations of the heavy equipment

  14. Novel ST-MUSIC-based spectral analysis for detection of ULF geomagnetic signals anomalies associated with seismic events in Mexico

    OpenAIRE

    Omar Chavez; Juan Pablo Amezquita-Sanchez; Martin Valtierra-Rodriguez; Jose Antonio Cruz-Abeyro; Anatoliy Kotsarenko; Jesus Roberto Millan-Almaraz; Aurelio Dominguez-Gonzalez; Eduardo Rojas

    2016-01-01

    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 a...

  15. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets in a NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond L.; Kim, Hak; Phan, Anthony; Seidleck, Christina; Label, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found that the single-event upset (SEU) cross section varied inversely with cumulative fluence. We attribute the effect to the variable upset sensitivities of the memory cells. Furthermore, the effect impacts only single cell upsets in general. The rate of multiple-bit upsets remained relatively constant with fluence. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, traditional SEE testing techniques may underestimate the on-orbit event rate for a device with variable upset sensitivity.

  16. Low-energy neutron-induced single-event upsets in static random access memory

    International Nuclear Information System (INIS)

    Guo Xiaoqiang; Guo Hongxia; Wang Guizhen; Ling Dongsheng; Chen Wei; Bai Xiaoyan; Yang Shanchao; Liu Yan

    2009-01-01

    The visual analysis method of data process was provided for neutron-induced single-event upset(SEU) in static random access memory(SRAM). The SEU effects of six CMOS SRAMs with different feature size(from 0.13 μm to 1.50 μm) were studied. The SEU experiments were performed using the neutron radiation environment at Xi'an pulsed reactor. And the dependence of low-energy neutron-induced SEU cross section on SRAM's feature size was given. The results indicate that the decreased critical charge is the dominant factor for the increase of single event effect sensitivity of SRAM devices with decreased feature size. Small-sized SRAM devices are more sensitive than large-sized ones to single event effect induced by low-energy neutrons. (authors)

  17. 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.

  18. Single tagged 2γ events with BGO, ALR, and VSAT of L3

    Science.gov (United States)

    Baksay, Laszlo; Dehmelt, Klaus; Hohlmann, Marcus

    2003-11-01

    In order to extend the investigation of the Q^2 evolution of the hadronic structure function F_2^γ with L3, to Q^2 as low as 0.5GeV^2 and as high as 3850GeV^2, we will include the electromagnetic calorimeters (BGO), active lead rings (ALR), and the very small angle tagging detectors (VSAT) as tagging devices for single tagged 2γ events. Strategies for selecting events with these detector components will be presented.

  19. Overview of software tools for modeling single event upsets in microelectronic devices

    Directory of Open Access Journals (Sweden)

    Anatoly Alexandrovich Smolin

    2016-10-01

    Full Text Available The paper presents the results of the analysis of existing simulation tools for evaluation of single event upset susceptibility of microelectronic devices with deep sub-micron feature sizes. This simulation tools are meant to replace obsolete approach to single event rate estimation based on integral rectangular parallelepiped model. Three main approaches implemented in simulation tools are considered: combined use of particle transport codes and rectangular parallelepiped model, combined use of particle transport codes and analytical models of charge collection and circuit simulators, and combined use of particle transport codes and TCAD simulators.

  20. Impact of NBTI Aging on the Single-Event Upset of SRAM Cells

    CERN Document Server

    Bagatin, M; Gerardin, Simone; Paccagnella, Alessandro; Bagatin, Marta

    2010-01-01

    We analyzed the impact of negative bias temperature instability (NBTI) on the single-event upset rate of SRAM cells through experiments and SPICE simulations. We performed critical charge simulations introducing different degradation patterns in the cells, in three technology nodes, from 180 to 90 nm. The simulations results were checked with alpha-particle and heavy-ion irradiations on a 130-nm technology. Both simulations and experimental results show that NBTI degradation does not significantly affect the single-event upset SRAM cell rate as long as the parametric drift induced by aging is within 10\\%.

  1. Multichannel long period seismic data acquisition system

    International Nuclear Information System (INIS)

    Kolvankar, V.G.; Rao, D.S.

    1990-01-01

    This paper discusses the specifications and performance of an eight channel long period seismic digital data acquisition system, which is developed and installed at Seismic Array Station, Gauribidanur, Karnataka State. The paper describes how these data in an unedited form are recorded on a single track of magnetic tape inter-mittantly, which has resulted in recording of 50 days data on a single tapespool. A time indexing technique which enables quick access to any desired portion of a recorded tape is also discussed. Typical examples of long period seismic event signals recorded by this system are also illustrated. Various advantages, the system provides over the analog multichannel instrumentation tape recording system, operating at Seismic Array Station for th e last two decades, are also discussed. (author). 7 figs

  2. Cross-correlation analysis of 2012-2014 seismic events in Central-Northern Italy: insights from the geochemical monitoring network of Tuscany

    Science.gov (United States)

    Pierotti, Lisa; Facca, Gianluca; Gherardi, Fabrizio

    2015-04-01

    Since late 2002, a geochemical monitoring network is operating in Tuscany, Central Italy, to collect data and possibly identify geochemical anomalies that characteristically occur before regionally significant (i.e. with magnitude > 3) seismic events. The network currently consists of 6 stations located in areas already investigated in detail for their geological setting, hydrogeological and geochemical background and boundary conditions. All these stations are equipped for remote, continuous monitoring of selected physicochemical parameters (temperature, pH, redox potential, electrical conductivity), and dissolved concentrations of CO2 and CH4. Additional information are obtained through in situ discrete monitoring. Field surveys are periodically performed to guarantee maintenance and performance control of the sensors of the automatic stations, and to collect water samples for the determination of the chemical and stable isotope composition of all the springs investigated for seismic precursors. Geochemical continuous signals are numerically processed to remove outliers, monitoring errors and aseismic effects from seasonal and climatic fluctuations. The elaboration of smoothed, long-term time series (more than 200000 data available today for each station) allows for a relatively accurate definition of geochemical background values. Geochemical values out of the two-sigma relative standard deviation domain are inspected as possible indicators of physicochemical changes related to regional seismic activity. Starting on November 2011, four stations of the Tuscany network located in two separate mountainous areas of Northern Apennines separating Tuscany from Emilia-Romagna region (Equi Terme and Gallicano), and Tuscany from Emilia-Romagna and Umbria regions (Vicchio and Caprese Michelangelo), started to register anomalous values in pH and CO2 partial pressure (PCO2). Cross-correlation analysis indicates an apparent relationship between the most important seismic

  3. Selection of Single Top Events with the CMS Detector at LHC

    CERN Document Server

    Abramov, Victor; Slabospitsky, Sergey; Najafabadi, M Mohammadi; Giammanco, Andrea; Tenchini, Roberto; Boos, Edouard; Dudko, Lev; Savrin, Viktor; Sherstnev, Alexander; Kalinin, Sergey; Drozdetsky, A A

    2006-01-01

    The detection of single-top events with CMS is discussed. Two selections are proposed, aimed to measure single top production in the Standard Model t- and s-channel, respectively. The perspectives of the measurements for an integrated luminosity of 10 fb-1 are described. The results are based on detailed detector simulations, either based on GEANT4, or on faster techniques. The reconstruction procedures developed by the CMS Collaboration are utilized.

  4. Martian seismicity

    International Nuclear Information System (INIS)

    Goins, N.R.; Lazarewicz, A.R.

    1979-01-01

    During the Viking mission to Mars, the seismometer on Lander II collected approximately 0.24 Earth years of observations data, excluding periods of time dominated by wind-induced Lander vibration. The ''quiet-time'' data set contains no confirmed seismic events. A proper assessment of the significance of this fact requires quantitative estimates of the expected detection rate of the Viking seismometer. The first step is to calculate the minimum magnitude event detectable at a given distance, including the effects of geometric spreading, anelastic attenuation, seismic signal duration, seismometer frequency response, and possible poor ground coupling. Assuming various numerical quantities and a Martian seismic activity comparable to that of intraplate earthquakes, the appropriate integral gives an expected annual detection rate of 10 events, nearly all of which are local. Thus only two to three events would be expected in the observational period presently on hand and the lack of observed events is not in gross contradiction to reasonable expectations. Given the same assumptions, a seismometer 20 times more sensitive than the present instrument would be expected to detect about 120 events annually

  5. Instrumental seismicity of the Amatrice earthquake epicentral area: a review

    Directory of Open Access Journals (Sweden)

    Maria Grazia Ciaccio

    2016-12-01

    Full Text Available This study presents a review of the instrumental seismicity of the Norcia-Amatrice area (central Italy where a still on-going seismic sequence started on August 24th 2016 with a Mw6.0 earthquake. The review is based on the analysis of the seismic catalogs 1981-2016, the CMT (Centroid Moment Tensor solutions and the TDMT (Time Domain Moment Tensor solutions, dividing the area into three regions based on the main seismic sequences preceding the Amatrice 2016 mainshock. The seismicity of this region is characterized by different types of activity: single events, minor sequences and swarms with hypocenters within the upper 15 km of the crust. Small-magnitude seismic sequences on March 2007 with maximum Mw3.9, and one earthquake on March 2012, Mw37, not followed by significant seismicity, affected the area east of the Norcia, close to the Mw 5.4 aftershock of the Amatrice 2016 sequence. In the central area, near Accumoli, and in the southern sector close to Amatrice, minor seismic sequences occurred on February 2014 Ml3.5 and on November 2013 Mw3.7 respectively. We integrated hypocentral locations and fault plane solutions to give a first look at the main features of the instrumental seismicity compared to the present seismic sequence in order to relate the seismicity patterns to seismogenic structures of this area of the central Italy.

  6. High-energy heavy ion testing of VLSI devices for single event ...

    Indian Academy of Sciences (India)

    Unknown

    Single event upset is defined by NASA as 'radiation- induced errors in microelectronic circuits caused when charged particles (usually from the radiation belts or from cosmic rays) lose energy by ionizing the medium through which they pass, leaving behind a wake of elec- tron-hole pairs'. SEU are transient soft errors and ...

  7. Single Event Testing on Complex Devices: Test Like You Fly versus Test-Specific Design Structures

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2014-01-01

    We present a framework for evaluating complex digital systems targeted for harsh radiation environments such as space. Focus is limited to analyzing the single event upset (SEU) susceptibility of designs implemented inside Field Programmable Gate Array (FPGA) devices. Tradeoffs are provided between application-specific versus test-specific test structures.

  8. Single Event Upset Energy Dependence In a Buck-Converter Power Supply Design

    CERN Document Server

    Drake, G; The ATLAS collaboration; Gopalakrishnan, A; Mahadik, S; Mellado, B; Proudfoot, J; Reed, R; Senthilkumaran, A; Stanek, R

    2012-01-01

    We present a study of Single Event Upsets (SEU) performed on a commercial pulse-width modulator controller chip for switching power supplies. We performed tests to study the probability of an SEU occurring as a function of incident particle (hadron) energy. We discuss the performance of the circuit, and present a solution using external circuitry to effectively eliminate the effect.

  9. Simulation aided hardening of N-channel power MOSFETs to prevent single event burnout

    International Nuclear Information System (INIS)

    Dachs, C.; Palau, J.M.; Bruguier, G.; Gasiot, J.; Roubaud, F.; Tastet, P.; Calvet, M.C.; Calvel, P.

    1995-01-01

    2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p + plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures

  10. Single-event burnout of power MOSFET devices for satellite application

    International Nuclear Information System (INIS)

    Xue Yuxiong; Tian Kai; Cao Zhou; Yang Shiyu; Liu Gang; Cai Xiaowu; Lu Jiang

    2008-01-01

    Single-event burnout (SEB) sensitivity was tested for power MOSFET devices, JTMCS081 and JTMCS062, which were made in Institute of Microelectronics, Chinese Academy of Sciences, using californium-252 simulation source. SEB voltage threshold was found for devices under test (DUT). It is helpful for engineers to choose devices used in satellites. (authors)

  11. First nondestructive measurements of power MOSFET single event burnout cross sections

    International Nuclear Information System (INIS)

    Oberg, D.L.; Wert, J.L.

    1987-01-01

    A new technique to nondestructively measure single event burnout cross sections for N-channel power MOSFETs is presented. Previous measurements of power MOSFET burnout susceptibility have been destructive and thus not conducive to providing statistically meaningful burnout probabilities. The nondestructive technique and data for various device types taken at several accelerators, including the LBL Bevalac, are documented. Several new phenomena are observed

  12. Re-Verification of the IRHN57133SE and IRHN57250SE for Single Event Gate Rupture and Single Event Burnout

    Science.gov (United States)

    Scheick, Leif

    2010-01-01

    The vertical metal oxide semiconductor field-effect transistor (MOSFET) is a widely used power transistor onboard a spacecraft. The MOSFET is typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single event gate rupture (SEGR) or single event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. These radiation hardened devices are not immune to SEGR or SEB but, rather, can exhibit them at a much more damaging ion than their non-radiation hardened counterparts. See [1] through [5] for more information.This effort was to investigate the SEGR and SEB responses of two power MOSFETs from IR(the IRHN57133SE and the IRHN57250SE) that have recently been produced on a new fabrication line. These tests will serve as a limited verification of these parts, but it is acknowledged that further testing on the respective parts may be needed for some mission profiles.

  13. Seismic detection of meteorite impacts on Mars

    Science.gov (United States)

    Teanby, N. A.; Wookey, J.

    2011-05-01

    Meteorite impacts provide a potentially important seismic source for probing Mars' interior. It has recently been shown that new craters can be detected from orbit using high resolution imaging, which means the location of any impact-related seismic event could be accurately determined - thus improving the constraints that could be placed on internal structure using a single seismic station. This is not true of other seismic sources on Mars such as sub-surface faulting, which require location using multiple seismic stations. This study aims to determine the seismic detectability of meteorite impacts and assess whether they are a viable means of probing deep internal structure. First, we derive a relation between crater diameter and equivalent seismic moment based on observational data compiled from impact tests, controlled explosions, and earthquake seismology. Second, this relation was combined with updated cratering rates based on newly observed craters to derive the impact induced seismicity on Mars, which we estimate to total 10 13-10 14 N m per year. Finally, seismic waveform modelling was used to determine the detectability of these impacts based on reasonable assumptions about likely seismometer performance and background noise levels. For our nominal noise/instrument case we find that detectable impacts at teleseismic distances (source-receiver offsets greater than 60°) are very rare and occur approximately once every 10 years. For our most optimistic noise/instrument case, approximately one such event occurs each year. This suggests that using solely meteorite impacts is not a reliable way of probing the Martian interior, although local impacts are more frequently detectable and could provide important constraints on near surface seismic properties.

  14. Single Event Effects Test Facility Options at the Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Riemer, Bernie [ORNL; Gallmeier, Franz X [ORNL; Dominik, Laura J [ORNL

    2015-01-01

    Increasing use of microelectronics of ever diminishing feature size in avionics systems has led to a growing Single Event Effects (SEE) susceptibility arising from the highly ionizing interactions of cosmic rays and solar particles. Single event effects caused by atmospheric radiation have been recognized in recent years as a design issue for avionics equipment and systems. To ensure a system meets all its safety and reliability requirements, SEE induced upsets and potential system failures need to be considered, including testing of the components and systems in a neutron beam. Testing of integrated circuits (ICs) and systems for use in radiation environments requires the utilization of highly advanced laboratory facilities that can run evaluations on microcircuits for the effects of radiation. This paper provides a background of the atmospheric radiation phenomenon and the resulting single event effects, including single event upset (SEU) and latch up conditions. A study investigating requirements for future single event effect irradiation test facilities and developing options at the Spallation Neutron Source (SNS) is summarized. The relatively new SNS with its 1.0 GeV proton beam, typical operation of 5000 h per year, expertise in spallation neutron sources, user program infrastructure, and decades of useful life ahead is well suited for hosting a world-class SEE test facility in North America. Emphasis was put on testing of large avionics systems while still providing tunable high flux irradiation conditions for component tests. Makers of ground-based systems would also be served well by these facilities. Three options are described; the most capable, flexible, and highest-test-capacity option is a new stand-alone target station using about one kW of proton beam power on a gas-cooled tungsten target, with dual test enclosures. Less expensive options are also described.

  15. Electrochemical Dynamics of a Single Platinum Nanoparticle Collision Event for the Hydrogen Evolution Reaction.

    Science.gov (United States)

    Xiang, Zhi-Peng; Deng, Hai-Qiang; Peljo, Pekka; Fu, Zhi-Yong; Wang, Su-Li; Mandler, Daniel; Sun, Gong-Quan; Liang, Zhen-Xing

    2018-03-19

    Chronoamperometry was used to study the dynamics of Pt nanoparticle (NP) collision with an inert ultramicroelectrode via electrocatalytic amplification (ECA) in the hydrogen evolution reaction. ECA and dynamic light scattering (DLS) results reveal that the NP colloid remains stable only at low proton concentrations (1.0 mm) under a helium (He) atmosphere, ensuring that the collision events occur at genuinely single NP level. Amperometry of single NP collisions under a He atmosphere shows that each discrete current profile of the collision event evolves from spike to staircase at more negative potentials, while a staircase response is observed at all of the applied potentials under hydrogen-containing atmospheres. The particle size distribution estimated from the diffusion-controlled current in He agrees well with electron microscopy and DLS observations. These results shed light on the interfacial dynamics of the single nanoparticle collision electrochemistry. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The nematocyst extract of Hydra attenuata causes single channel events in lipid bilayers.

    Science.gov (United States)

    Weber, J; Schürholz, T; Neumann, E

    1990-01-01

    The nematocyst extract of Hydra attenuata causes single conductance events in reconstituted planar lipid membranes as well as in inside-out patches derived from liposomes. The smallest single channel conductance level of the toxins is 110 pS. The conductance levels increase stepwise with time up to 2000 pS. These large conductance jumps indicate channel cooperativity. If the membrane-voltage is changed from positive to negative values, the single channel events become undefined and noisy, indicating major reorganizations of the proteins which form the channels. The molecular properties of the ionophoric component(s) of the nematocyst extract may help explain the observed macroscopic effects, such as hemolysis of human erythrocytes, after addition of the nematocyst extract.

  17. Single event effects and performance predictions for space applications of RISC processors

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrough, J.R.; Colella, N.J.; Denton, S.M.; Shaeffer, D.L.; Shih, D.; Wilburn, J.W. (Lawrence Livermore National Lab., CA (United States)); Coakley, P.G. (JAYCOR, San Diego, CA (United States)); Casteneda, C. (Crocker Nuclar Lab., Davis, CA (United States)); Koga, R. (Aerospace Corp., El Segundo, CA (United States)); Clark, D.A.; Ullmann, J.L. (Los Alamos National Lab., NM (United States))

    1994-12-01

    Proton and ion Single Event Phenomena (SEP) tests were performed on 32-b processors including R3000A's from all commercial manufacturers along with the Performance PR3400 family, Integrated Device Technology Inc. 79R3081, LSI Logic Corporation LR33000HC, and Intel i80960MX parts. The microprocessors had acceptable upset rates for operation in a low earth orbit or a lunar mission such as CLEMENTINE with a wide range in proton total dose failure. Even though R3000A devices are 60% smaller in physical area than R3000 devices, there was a 340% increase in device Single Event Upset (SEU) cross section. Software tests of varying complexity demonstrate that registers and other functional blocks using register architecture dominate the cross section. The current approach of giving a single upset cross section can lead to erroneous upset rates depending on the application software.

  18. Single-trial normalization for event-related spectral decomposition reduces sensitivity to noisy trials

    Directory of Open Access Journals (Sweden)

    Romain eGrandchamp

    2011-09-01

    Full Text Available In EEG research, the classical Event-Related Potential (ERP model often proves to be a limited method when studying complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as Event-Related Spectral Perturbation (ERSP – and its variant ERS (Event-Related Synchronization and ERD (Event-Related Desynchronization – have been used over the past 20-years. They represent average spectral changes in response to a stimulus.These spectral methods do not have strong consensus for comparing pre and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time-frequency responses and behavior when performing statistical inference testing compared to classical ERSP methods.

  19. Single-Event Effect Testing of the Linear Technology LTC6103HMS8#PBF Current Sense Amplifier

    Science.gov (United States)

    Yau, Ka-Yen; Campola, Michael J.; Wilcox, Edward

    2016-01-01

    The LTC6103HMS8#PBF (henceforth abbreviated as LTC6103) current sense amplifier from Linear Technology was tested for both destructive and non-destructive single-event effects (SEE) using the heavy-ion cyclotron accelerator beam at Lawrence Berkeley National Laboratory (LBNL) Berkeley Accelerator Effects (BASE) facility. During testing, the input voltages and output currents were monitored to detect single event latch-up (SEL) and single-event transients (SETs).

  20. Constraints on Correlation between the Anomalous Behaviour of Electromagnetic Normalized Functions (ENF and the Intermediate Depth Seismic Events Occurred in Vrancea Zone (Romania

    Directory of Open Access Journals (Sweden)

    Dumitru Stanica Dragos ArmStanica

    2010-01-01

    Full Text Available This paper is focused on a specific methodology able to emphasize the correlation between anomalous behaviour of electromagnetic normalized functions and intermediate depth seismic events which have occurred in the Vrancea zone and pointing out the main constraints related to them. The lithospheric conductivity changes produced prior to and during an earthquake, as a sequence of the dehydration of the rocks, associated with rupturing processes and fluid migration through faulting systems developed inside and close vicinity to foci, could be detected by means of the peculiar features of the electromagnetic normalized functions taken throughout the frequency range DC-10-2 Hz.

  1. Lessons from M 7.2 Seismic Event and How to Preserve Awareness Forty Years Later: The Case of the Vrancea, Romania, March 4, 1977 Earthquake

    Science.gov (United States)

    Craifaleanu, Iolanda-Gabriela; Georgescu, Emil-Sever; Dragomir, Claudiu-Sorin

    2016-10-01

    Almost four decades after the MG-R = 7.2 (Mw =7.4) catastrophic earthquake of March 4, 1977 hit Romania, the population fears a new strong earthquake; however, awareness on preparedness and mitigation measures is rather low. As the last Mw > 6 has occurred in 1990, there is an increasing percentage of young population that has not yet witnessed a strong earthquake, and which has a rather fuzzy representation of urban and geological earthquake effects. After each strong seismic event in the past, due to its specific attributions, the National Institute for Building Research, INCERC, collected a considerable amount of information about the earthquake effects on built environment and lifelines, geological effects etc. To this, information from various documentary sources about damage caused by historic earthquakes was added by the institute's specialists. Stored today in the archives of the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development, “URBAN-INCERC”, INCERC Bucharest Branch, this information is invaluable today for evaluating the present and future seismic risk of the country. Nonetheless, it could represent an essential educational resource for university students and young professionals in the field of civil engineering, seismology, geology, economy, sociology, history etc. and for raising population awareness on seismic risk mitigation measures. The paper presents new approaches for the dissemination and re-valuation of the March 4, 1977 earthquake data, from the perspective of present scientific knowledge.

  2. Seismic instrumentation

    International Nuclear Information System (INIS)

    Maubach, K.

    1982-01-01

    For better understanding of the specification for seismic instrumentation of a nuclear power plant, the lecture gives some fundamental remarks to the seismic risk in the Federal Republic of Germany and to the data characterizing an earthquake event. Coming from the geophysical properties of an earthquake, the quantities are explained which are used in the design process of nuclear power plants. This process is shortly described in order to find the requirements for the specification of the seismic instrumentation. In addition the demands of licensing authorities are given. As an example the seismic instrumentation of KKP-1, BWR, is shown. The paper deals with kind and number of instruments, their location in the plant and their sensitivity and calibration. Final considerations deal with the evaluation of measured data and with plant operation after an earthquake. Some experience concerning the earthquake behaviour of equipment not designed to withstand earthquake loads is mentioned. This experience has initiated studies directed to quantification of the degree of conservatism of the assumptions in the seismic design of nuclear power plants. A final garget of these studies are more realistic design rules. (RW)

  3. Relationship between single-event upset immunity and fabrication processes of recent memories

    International Nuclear Information System (INIS)

    Nemoto, N.; Shindou, H.; Kuboyama, S.; Matsuda, S.; Itoh, H.; Okada, S.; Nashiyama, I.

    1999-01-01

    Single-Event upset (SEU) immunity for commercial devices were evaluated by irradiation tests using high-energy heavy ions. We show test results and describe the relationship between observed SEU and structures/fabrication processes. We have evaluated single-even upset (SEU) tolerance of recent commercial memory devices using high energy heavy ions in order to find relationship between SEU rate and their fabrication process. It was revealed that the change of the process parameter gives much effect for the SEU rate of the devices. (authors)

  4. A Stochastic Single-Molecule Event Triggers Phenotype Switching of a Bacterial Cell

    Science.gov (United States)

    Xie, Sunney; Choi, Paul; Cai, Long

    2009-03-01

    By monitoring fluorescently labeled lactose permease with single-molecule sensitivity, we investigated the molecular mechanism of how an Escherichia coli cell with the lac operon switches from one phenotype to another. At intermediate inducer concentrations, a population of genetically identical cells exhibits two phenotypes: induced cells with highly fluorescent membranes and uninduced cells with a small number of membrane-bound permeases. We found that this basal-level expression results from partial dissociation of the tetrameric lactose repressor from one of its operators on looped DNA. In contrast, infrequent events of complete dissociation of the repressor from DNA result in large bursts of permease expression that trigger induction of the lac operon. Hence, a stochastic single-molecule event determines a cell's phenotype.

  5. Simulating single-event burnout of n-channel power MOSFET's

    International Nuclear Information System (INIS)

    Johnson, G.H.; Hohl, J.H.; Schrimpf, R.D.; Galloway, K.F.

    1993-01-01

    Heavy ions are ubiquitous in a space environment. Single-event burnout of power MOSFET's is a sudden catastrophic failure mechanism that is initiated by the passage of a heavy ion through the device structure. The passage of the heavy ion generates a current filament that locally turns on a parasitic n-p-n transistor inherent to the power MOSFET. Subsequent high currents and high voltage in the device induce second breakdown of the parasitic bipolar transistor and hence meltdown of the device. This paper presents a model that can be used for simulating the burnout mechanism in order to gain insight into the significant device parameters that most influence the single-event burnout susceptibility of n-channel power MOSFET's

  6. Evaluation of single-event upset tolerance on 64Mbit DRAM and 16Mbit DRAM

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, N.; Shindou, H.; Matsuzaki, K.; Akutsu, T.; Matsuda, S. [National Space Development Agency of Japan, Tokyo (Japan); Hirao, T.; Itoh, H.; Nashiyama, I.

    1997-11-01

    In recent years, reduction in the mission cost is regarded as one of the most important matters, and thus much effort has been made to reduce the cost of electronic components used in spacecrafts without diminishing their performance. On this policy, there has been a growing interest in space application of commercial devices such as highly integrated memory ICs because of low prices and high performance of such devices. To ensure success in this application, it is indispensable to investigate radiation effects, e.g., single-event and total-dose effects, on commercial devices precisely. In the present study, we have evaluated single-event upset (SEU) tolerance for 1Mbit, 4Mbit SRAM and 16Mbit, 64Mbit DRAM by irradiation of high energy heavy ions such as 175MeV-Ar{sup 8+} and 450MeV-Xe{sup 23+}. We observed these SEU tolerance in space. (author)

  7. NASA Electronic Parts and Packaging Field Programmable Gate Array Single Event Effects Test Guideline Update

    Science.gov (United States)

    Berg, Melanie D.; LaBel, Kenneth A.

    2018-01-01

    The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

  8. Seismic hazard in low slip rate crustal faults, estimating the characteristic event and the most hazardous zone: study case San Ramón Fault, in southern Andes

    Science.gov (United States)

    Estay, Nicolás P.; Yáñez, Gonzalo; Carretier, Sebastien; Lira, Elias; Maringue, José

    2016-11-01

    Crustal faults located close to cities may induce catastrophic damages. When recurrence times are in the range of 1000-10 000 or higher, actions to mitigate the effects of the associated earthquake are hampered by the lack of a full seismic record, and in many cases, also of geological evidences. In order to characterize the fault behavior and its effects, we propose three different already-developed time-integration methodologies to define the most likely scenarios of rupture, and then to quantify the hazard with an empirical equation of peak ground acceleration (PGA). We consider the following methodologies: (1) stream gradient and (2) sinuosity indexes to estimate fault-related topographic effects, and (3) gravity profiles across the fault to identify the fault scarp in the basement. We chose the San Ramón Fault on which to apply these methodologies. It is a ˜ 30 km N-S trending fault with a low slip rate (0.1-0.5 mm yr-1) and an approximated recurrence of 9000 years. It is located in the foothills of the Andes near the large city of Santiago, the capital of Chile (> 6 000 000 inhabitants). Along the fault trace we define four segments, with a mean length of ˜ 10 km, which probably become active independently. We tested the present-day seismic activity by deploying a local seismological network for 1 year, finding five events that are spatially related to the fault. In addition, fault geometry along the most evident scarp was imaged in terms of its electrical resistivity response by a high resolution TEM (transient electromagnetic) profile. Seismic event distribution and TEM imaging allowed the constraint of the fault dip angle (˜ 65°) and its capacity to break into the surface. Using the empirical equation of Chiou and Youngs (2014) for crustal faults and considering the characteristic seismic event (thrust high-angle fault, ˜ 10 km, Mw = 6.2-6.7), we estimate the acceleration distribution in Santiago and the hazardous zones. City domains that are under

  9. Estimation of the LET threshold of single event upset of microelectronics in experiments with Cf-252

    International Nuclear Information System (INIS)

    Kuznetsov, N.V.; Nymmik, R.A.

    1996-01-01

    A method is proposed for analyzing single event upsets (SEU) in large scale integration circuits of random access memory (RAM) when exposed to Cf-252 fission fragments. The method makes is possible to find the RAM linear energy transfer (LET) threshold to be used for estimations of RAM SEU rates in space. The method is illustrated by analyzing experimental data for the 2 x 8 kbit CMOS/bulk RAM. (author)

  10. In-flight and ground testing of single event upset sensitivity in static RAMs

    International Nuclear Information System (INIS)

    Johansson, K.; Dyreklev, P.; Granbom, B.; Calvet, C.; Fourtine, S.; Feuillatre, O.

    1998-01-01

    This paper presents the results from in-flight measurements of single event upsets (SEU) in static random access memories (SRAM) caused by the atmospheric radiation environment at aircraft altitudes. The memory devices were carried on commercial airlines at high altitude and mainly high latitudes. The SEUs were monitored by a Component Upset Test Equipment (CUTE), designed for this experiment. The in flight results are compared to ground based testing with neutrons from three different sources

  11. Development of heavy-ion irradiation technique for single-event in semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Norio; Akutsu, Takao; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Naitoh, Ichiro; Itoh, Hisayoshi; Agematsu, Takashi; Kamiya, Tomihiro; Nashiyama, Isamu

    1997-03-01

    Heavy-ion irradiation technique has been developed for the evaluation of single-event effects on semiconductor devices. For the uniform irradiation of high energy heavy ions to device samples, we have designed and installed a magnetic beam-scanning system in a JAERI cyclotron beam course. It was found that scanned area was approximately 4 x 2 centimeters and that the deviation of ion fluence from the average value was less than 7%. (author)

  12. Prediction Methodology for Proton Single Event Burnout: Application to a STRIPFET Device

    CERN Document Server

    Siconolfi, Sara; Oser, Pascal; Spiezia, Giovanni; Hubert, Guillaume; David, Jean-Pierre

    2015-01-01

    This paper presents a single event burnout (SEB) sensitivity characterization for power MOSFETs, independent from tests, through a prediction model issued from TCAD analysis and the knowledge of device topology. The methodology is applied to a STRIPFET device and compared to proton data obtained at PSI, showing a good agreement in the order of magnitude of proton SEB cross section, and thus validating the prediction model as an alternative device characterization with respect to SEB.

  13. Results of single-event multilevel orthopedic surgery in children with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Akhmed Tomov

    2015-11-01

    Full Text Available Background: Single-event multilevel orthopedic surgery is a modern approach in the operative treatment of children with cerebral palsy. Methods: Single-event multilevel orthopedic surgery was carried out in 108 patients with cerebral palsy. Patients’ average age was 11.3±1.7 years. Surgical results were analyzed at follow-up after 18 to 24 months, by way of detailed physical examination, functional assessment, imaging, the Edinburgh Visual Gait Score and Gillette Functional Assessment Questionnaire. Results: In our series, 647 procedures were performed during 141 surgeries. Patients had an average of 4.59 procedures per surgery. Observational gait analysis showed an improvement in stance and swing gait phases in ambulatory children. According to the Gillette Functional Assessment Questionnaire, an increase of functional level was noted in 50 patients but did not change in 32 patients. Conclusions: For children with cerebral palsy, single-event multilevel surgery is defined as two or more surgical procedures of the soft tissue or bone at two or more anatomical levels during one operative procedure. In cases where a large volume of surgery is required, two separate operations with a short break in between, but requiring only one hospital admission and one rehabilitation period, are also included. This approach requires adapted methods of surgical intervention, and appropriate methods of anesthesia and pain control in the postoperative period to the start of rehabilitation. Compliance with the above principles allowed the necessary correction of orthopedic complications to be achieved in all cases.

  14. Accuracy of the detection of binding events using 3D single particle tracking.

    Science.gov (United States)

    Carozza, Sara; Culkin, Jamie; van Noort, John

    2017-01-01

    Nanoparticles can be used as markers to track the position of biomolecules, such as single proteins, inside living cells. The activity of a protein can sometimes be inferred from changes in the mobility of the attached particle. Mean Square Displacement analysis is the most common method to obtain mobility information from trajectories of tracked particles, such as the diffusion coefficient D . However, the precision of D sets a limit to discriminate changes in mobility caused by biological events from changes that reflect the stochasticity inherent to diffusion. This issue is of particular importance in an experiment aiming to quantify dynamic processes. Here, we present simulations and 3D tracking experiments with Gold Nanorods freely diffusing in glycerol solution to establish the best analysis parameters to extract the diffusion coefficient. We applied this knowledge to the detection of a temporary change in diffusion, as it can occur due to the transient binding of a particle to an immobile structure within the cell, and tested its dependence on the magnitude of the change in diffusion and duration of this event. The simulations show that the spatial accuracy of particle tracking generally does not limit the detection of short binding events. Careful analysis of the magnitude of the change in diffusion and the number of frames per binding event is required for accurate quantification of such events.

  15. Autonomous Gait Event Detection with Portable Single-Camera Gait Kinematics Analysis System

    Directory of Open Access Journals (Sweden)

    Cheng Yang

    2016-01-01

    Full Text Available Laboratory-based nonwearable motion analysis systems have significantly advanced with robust objective measurement of the limb motion, resulting in quantified, standardized, and reliable outcome measures compared with traditional, semisubjective, observational gait analysis. However, the requirement for large laboratory space and operational expertise makes these systems impractical for gait analysis at local clinics and homes. In this paper, we focus on autonomous gait event detection with our bespoke, relatively inexpensive, and portable, single-camera gait kinematics analysis system. Our proposed system includes video acquisition with camera calibration, Kalman filter + Structural-Similarity-based marker tracking, autonomous knee angle calculation, video-frame-identification-based autonomous gait event detection, and result visualization. The only operational effort required is the marker-template selection for tracking initialization, aided by an easy-to-use graphic user interface. The knee angle validation on 10 stroke patients and 5 healthy volunteers against a gold standard optical motion analysis system indicates very good agreement. The autonomous gait event detection shows high detection rates for all gait events. Experimental results demonstrate that the proposed system can automatically measure the knee angle and detect gait events with good accuracy and thus offer an alternative, cost-effective, and convenient solution for clinical gait kinematics analysis.

  16. Parasitic bipolar amplification in a single event transient and its temperature dependence

    International Nuclear Information System (INIS)

    Liu Zheng; Chen Shu-Ming; Chen Jian-Jun; Qin Jun-Rui; Liu Rong-Rong

    2012-01-01

    Using three-dimensional technology computer-aided design (TCAD) simulation, parasitic bipolar amplification in a single event transient (SET) current of a single transistor and its temperature dependence are studied. We quantify the contributions of different current components in a SET current pulse, and it is found that the proportion of parasitic bipolar amplification in total collected charge is about 30% in both 130-nm and 90-nm technologies. The temperature dependence of parasitic bipolar amplification and the mechanism of the SET pulse are also investigated and quantified. The results show that the proportion of charge induced by parasitic bipolar increases with rising temperature, which illustrates that the parasitic bipolar amplification plays an important role in the charge collection of a single transistor

  17. Rock mass response to strong ground motion generated by mining induced seismic events and blasting observed at the surface of the excavations in deep level gold mines in South Africa

    Science.gov (United States)

    Milev, Alexander; Durrheim, Ray; Ogasawara, Hiroshi

    2014-05-01

    The strong ground motion generated by mining induced seismic events was studied to characterize the rock mass response and to estimate the site effect on the surface of the underground excavations. A stand-alone instruments, especially designed for recording strong ground motions, were installed underground at a number of deep level gold mines in South Africa. The instruments were recording data at the surface of the stope hangingwalls. A maximum value of 3 m/s was measured. Therefore data were compared to the data recorded in the solid rock by the mine seismic networks to determine the site response. The site response was defined as the ratio of the peak ground velocity measured at the surface of the excavations to the peak ground velocity inferred from the mine seismic data measured in the solid rocks. The site response measured at all mines studied was found to be 9 ± 3 times larger on average. A number of simulated rockbursts were conducted underground in order to estimate the rock mass response when subjected to extreme ground motion and derive the attenuation factors in near field. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of the ground motion was found to be proportional to the distance from the source following R^-1.1 & R^-1.7 for compact rock and R^-3.1 & R^-3.4 for more fractured rock close to the surface of the tunnel. In addition the ground motion was compared to the quasi-static deformations taking place around the underground excavations. The quasi-static deformations were measured by means of strain, tilt and closure. A good correspondence

  18. Effectiveness Analysis of a Non-Destructive Single Event Burnout Test Methodology

    CERN Document Server

    Oser, P; Spiezia, G; Fadakis, E; Foucard, G; Peronnard, P; Masi, A; Gaillard, R

    2014-01-01

    It is essential to characterize power MosFETs regarding their tolerance to destructive Single Event Burnouts (SEB). Therefore, several non-destructive test methods have been developed to evaluate the SEB cross-section of power devices. A power MosFET has been evaluated using a test circuit, designed according to standard non-destructive test methods discussed in the literature. Guidelines suggest a prior adaptation of auxiliary components to the device sensitivity before the radiation test. With the first value chosen for the de-coupling capacitor, the external component initiated destructive events and affected the evaluation of the cross-section. As a result, the influence of auxiliary components on the device cross-section was studied. This paper presents the obtained experimental results, supported by SPICE simulations, to evaluate and discuss how the circuit effectiveness depends on the external components.

  19. Critical evaluation of the pulsed laser method for single event effects testing and fundamental studies

    International Nuclear Information System (INIS)

    Melinger, J.S.; Buchner, S.; McMorrow, D.; Stapor, W.J.; Weatherford, T.R.; Campbell, A.B.; Eisen, H.

    1994-01-01

    In this paper the authors present an evaluation of the pulsed laser as a technique for single events effects (SEE) testing. They explore in detail the important optical effects, such as laser beam propagation, surface reflection, and linear and nonlinear absorption, which determine the nature of laser-generated charge tracks in semiconductor materials. While there are differences in the structure of laser- and ion-generated charge tracks, they show that in many cases the pulsed laser remains an invaluable tool for SEE testing. Indeed, for several SEE applications, they show that the pulsed laser method represents a more practical approach than conventional accelerator-based methods

  20. Single Event Upset Energy Dependence In a Buck-Converter Power Supply Design

    CERN Document Server

    Drake, G; The ATLAS collaboration; De Lurgio, P; Stanek, R; Mellado, B; Gopalakrishnan, A; Mahadik, S; Reed, R; Senthilkumaran, A

    2012-01-01

    We present a study of Single Event Upsets performed on a commercial pulse-width modulator controller chip that we are using for a switching power supply design for the Atlas Tile Calorimeter at the LHC. We performed tests to study the probability of an SEU occurring as a function of incident particle (hadron) energy. We compare the results with prediction from theory. We discuss the performance of the circuit, and perform an analysis using Bendel parameters. We also present a solution that we found using external circuitry that eliminates the effect.

  1. Search for new phenomena using single photon events in the DELPHI detector at LEP

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Barbi, M S; Barbiellini, Guido; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gerdyukov, L N; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Korcyl, K; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Lokajícek, M; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G; Charpentier, Ph; Gavillet, Ph

    1997-01-01

    Data are presented on the reaction \\epem~\\into~\\gamma + no other detected particle at center-of-mass energies, \\sqs = 89.48 GeV, 91.26 GeV and 93.08 GeV. The cross section for this reaction is related directly to the number of light neutrino generations which couple to the \\zz boson, and to several other phenomena such as excited neutrinos, the production of an invisible `X' particle, a possible magnetic moment of the tau neutrino, and neutral monojets. Based on the observed number of single photon events, the number of light neutrinos which couple to the \\zz is measured to be N_\

  2. The associated charged particle multiplicity of high-p/sub T/ pi /sup 0/ and single-photon events

    CERN Document Server

    Diakonou, M; Albrow, M G; Almehed, S; Benary, O; Bøggild, H; Botner, O; Cnops, A M; Cockerill, D J A; Dagan, S; Dahl-Jensen, Erik; Dahl-Jensen, I; Damgaard, G; Fabjan, Christian Wolfgang; Filippas-Tassos, A; Fokitis, E; Fowler, E C; Hallgren, A; Hansen, K H; Henning, S; Hood, D M; Hooper, J; Jarlskog, G; Karpathopoulos, S; Killian, T; Kourkoumelis, C; Kreisler, M; Lissauer, D; Lörstad, B; Ludlam, T; Mannelli, I; McCubbin, N A; Melin, A; Mjörnmark, U; Møller, R; Molzon, W; Mouzourakis, P; Nielsen, B S; Nielsen, S O; Nilsson, A; Oren, Y; Palmer, R B; Rahm, David Charles; Rehak, P; Resvanis, L K; Rosselt, L; Schistad, B; Stumer, I; Svensson, L; von Dardel, Guy F; Willis, W J

    1980-01-01

    The associated charged particle multiplicities of high-p/sub T/ pi /sup 0/ and single-photon events were measured at the CERN intersecting storage rings using lead/liquid-argon calorimeters and a scintillation counter array placed around the intersection region. The average multiplicity on the trigger side for the single-photon events was found to be significantly lower than that for the pi /sup 0/ events. The away-side multiplicity for both pi /sup 0/ and single- photon events increases with the trigger particle p/sub T/, but, at a fixed p/sub T/, the direct photon sample was found to have a slightly lower average multiplicity. The differences in the event structure can be explained if a large fraction of the single photons are produced via qg to gamma q constituent scattering. (16 refs).

  3. Multiple Event Analysis of the 2008 Mw 7.9 Wenchuan Earthquake: Implications for Variations in Radiated Seismic Energy During Faulting

    Directory of Open Access Journals (Sweden)

    Ruey-Der Hwang

    2013-01-01

    Full Text Available A forward modeling of P-waves for the 2008 Wenchuan earthquake revealed at least seven sub-events that occurred during faulting with the largest event (i.e., the third sub-event located at a position ~50 km northeast of the epicenter. Simulations of P-waves showed that it would be more appropriate to model the P-waves using thrust faulting for the first three sub-events and using strike-slip faulting for the last four. In other words, the faulting for the 2008 Wenchuan earthquake was composed substantially of two mechanisms; the former was a thrust faulting and the latter was a strike-slip rupture. The mechanical transition was near the town of Beichuan, ~100 km northeast of the epicenter. Variations in radiated seismic energy (ES showed the largest ES released from the fourth sub-event. Results also indicated remarkable distinctions between ES and ES0 (called the available energy. On the whole, the total ES, which was higher than ES0 estimated from static stress drop, suggested that the earthquake should be interrupted by a stress model of abrupt-locking. Further, the former thrust faulting released a relatively lower amount of ES than the latter strike-slip event. Orowan¡¦s stress model, i.e., ES ≈ ES0, can specify former thrust ruptures implying a high rupture velocity. Because ES > ES0 for latter strike-slip ruptures, a stress model of abrupt-locking, implying higher dynamic stress drop and lower friction during an earthquake, can account for the feature of the latter ruptures. This might suggest that the 2008 Wenchuan earthquake should have a high rupture velocity, perhaps approaching the crustal S-wave velocity or even higher.

  4. Patients with single ventricle physiology undergoing noncardiac surgery are at high risk for adverse events.

    Science.gov (United States)

    Brown, Morgan L; DiNardo, James A; Odegard, Kirsten C

    2015-08-01

    intraoperative adverse events (9.8%) including: arrhythmias requiring treatment (n = 4), conversion from sedation to a general anesthetic (n = 2), difficult airway (n = 1), inadvertent extubation with desaturation and bradycardia (n = 1), hypotension and desaturation (n = 1), and cardiac arrest (n = 1). Postoperative events (surgery in a high-risk subgroup of palliated cardiac patients with single ventricle physiology. However, 11.8% of patients had an adverse event associated with their anesthetic. © 2015 John Wiley & Sons Ltd.

  5. Kernel PLS Estimation of Single-trial Event-related Potentials

    Science.gov (United States)

    Rosipal, Roman; Trejo, Leonard J.

    2004-01-01

    Nonlinear kernel partial least squaes (KPLS) regressior, is a novel smoothing approach to nonparametric regression curve fitting. We have developed a KPLS approach to the estimation of single-trial event related potentials (ERPs). For improved accuracy of estimation, we also developed a local KPLS method for situations in which there exists prior knowledge about the approximate latency of individual ERP components. To assess the utility of the KPLS approach, we compared non-local KPLS and local KPLS smoothing with other nonparametric signal processing and smoothing methods. In particular, we examined wavelet denoising, smoothing splines, and localized smoothing splines. We applied these methods to the estimation of simulated mixtures of human ERPs and ongoing electroencephalogram (EEG) activity using a dipole simulator (BESA). In this scenario we considered ongoing EEG to represent spatially and temporally correlated noise added to the ERPs. This simulation provided a reasonable but simplified model of real-world ERP measurements. For estimation of the simulated single-trial ERPs, local KPLS provided a level of accuracy that was comparable with or better than the other methods. We also applied the local KPLS method to the estimation of human ERPs recorded in an experiment on co,onitive fatigue. For these data, the local KPLS method provided a clear improvement in visualization of single-trial ERPs as well as their averages. The local KPLS method may serve as a new alternative to the estimation of single-trial ERPs and improvement of ERP averages.

  6. Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions

    CERN Document Server

    Hou Ming Dong; LiuJie; Wang Zhi Guang; Jin Yun Fan; Zhu Zhi Yong; Zhen Hong Lou; Liu Chang Long; Chen Xiao Xi; Wei Xin Guo; Zhang Li; Fan You Cheng; Zhu Zhou Rong; Zhang Yiting

    2002-01-01

    Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions in different batches of 32k x 8 bits static random access memory are studied. The incident angle dependences of the cross sections for single event upset and single event latch up are presented. The SEE cross sections are plotted versus energy loss instead of linear energy transfer value in sensitive region. The depth of sensitive volume and thickness of 'dead' layer above the sensitive volume are estimated

  7. Primary single event effect studies on Xilinx 28-nm System-on-Chip (SoC)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yao [Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Liu, Shuhuan, E-mail: shuhuanliu@126.com [Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Du, Xuecheng; Yuan, Yuan; He, Chaohui [Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Ren, Xiaotang [Peking University, Beijing 100000 (China); Du, Xiaozhi; Li, Yonghong [Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-09-21

    Single Event Effect (SEE) on Xilinx 28-nm System-on-Chip (SoC) was investigated by both simulation and experiments in this study. In the simulation process, typical structure of NAND gate and flip-flop in SoC were designed using Cadence tool. Various kinds of radiation were simulated as pulsed current source in consideration of multilayer wiring and energy loss before reaching the sensitive area. The circuit modules were simulated as SEE occurred and malfunctioned when pulsed current source existed. The changes of the circuit modules output were observed when pulsed current signals were placed at different sensitive nodes or the circuit operated under different conditions. The sensitive nodes in typical modules and the possible reasons of test program malfunction were primarily studied. In the experimental process, SoC chip was irradiated with α particles, protons and laser respectively. The irradiation test results showed that Single Event Upset (SEU) occurred in typical modules of SoC, in accordance with the simulation results.

  8. Single-Event Effect Performance of a Conductive-Bridge Memory EEPROM

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Berg, Melanie; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Seidleck, Christina; LaBel, Kenneth

    2015-01-01

    We investigated the heavy ion single-event effect (SEE) susceptibility of the industry’s first stand-alone memory based on conductive-bridge memory (CBRAM) technology. The device is available as an electrically erasable programmable read-only memory (EEPROM). We found that single-event functional interrupt (SEFI) is the dominant SEE type for each operational mode (standby, dynamic read, and dynamic write/read). SEFIs occurred even while the device is statically biased in standby mode. Worst case SEFIs resulted in errors that filled the entire memory space. Power cycle did not always clear the errors. Thus the corrupted cells had to be reprogrammed in some cases. The device is also vulnerable to bit upsets during dynamic write/read tests, although the frequency of the upsets are relatively low. The linear energy transfer threshold for cell upset is between 10 and 20 megaelectron volts per square centimeter per milligram, with an upper limit cross section of 1.6 times 10(sup -11) square centimeters per bit (95 percent confidence level) at 10 megaelectronvolts per square centimeter per milligram. In standby mode, the CBRAM array appears invulnerable to bit upsets.

  9. A single prolific r-process event preserved in an ultra-faint dwarf galaxy

    Science.gov (United States)

    Ji, Alexander; Frebel, Anna; Chiti, Anirudh; Simon, Joshua

    2016-03-01

    The heaviest elements in the periodic table are synthesized through the r-process, but the astrophysical site for r-process nucleosynthesis is still unknown. Ultra-faint dwarf galaxies contain a simple fossil record of early chemical enrichment that may determine this site. Previous measurements found very low levels of neutron-capture elements in ultra-faint dwarfs, preferring supernovae as the r-process site. I present high-resolution chemical abundances of nine stars in the recently discovered ultra-faint dwarf Reticulum II, which display extremely enhanced r-process abundances 2-3 orders of magnitude higher than the other ultra-faint dwarfs. Stars with such extreme r-process enhancements are only rarely found in the Milky Way halo. The r-process abundances imply that the neutron-capture material in Reticulum II was synthesized in a single prolific event that is incompatible with r-process yields from ordinary core-collapse supernovae. Reticulum II provides an opportunity to discriminate whether the source of this pure r-process signature is a neutron star merger or magnetorotationally driven supernova. The single event is also a uniquely stringent constraint on the metal mixing and star formation history of this ultra-faint dwarf galaxy.

  10. Interpretation of seismic section by acoustic modeling. Study of large amplitude events; Hadoba modeling ni yoru jishin tansa danmen no kaishaku. Kyoshinhaba event ni taisuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Tamagawa, T.; Matsuoka, T.; Sato, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Minegishi, M.; Tsuru, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-05-01

    A large amplitude event difficult to interpret was discovered in the overlap section in offset data beyond 10km targeting at deep structures, and the event was examined. A wave field modeling was carried out by use of a simplified synclinal structure model because it had been estimated that the large amplitude event had something to do with a synclinal structure. A pseudospectral program was used for modeling the wave field on the assumption that the synclinal structure model would be an acoustic body and that the surface would contain free boundaries and multiple reflection. It was found as the result that a discontinuous large amplitude event is mapped out in the synclinal part of the overlap section when a far trace is applied beyond the structure during a CMP overlap process. This can be attributed to the concentration of energy produced by multiple reflection in the synclinal part and by the reflection waves beyond the critical angle. Accordingly, it is possible that phenomena similar to those encountered in the modeling process are emerging during actual observation. 2 refs., 8 figs.

  11. WiggleView : Visualizing Large Seismic Datasets

    Science.gov (United States)

    Nayak, A. M.; Leigh, J.; Johnson, A.; Russo, R.; Morin, P.; Laughbon, C.; Ahern, T.

    2002-12-01

    Wiggleview is a tool for visualizing seismic data collected from a worldwide network of seismometers. The visualization consists of overlaying familiar 2D seismic traces recorded for the N-S, E-W and vertical components of the earth's displacement over the topographic map of the affected area. In addition, a 3D particle trace consisting of the integration of these 3 components provides a depiction of how an object placed at a particular seismic recording station would shake at the instant of the event. Data for the seismic events is obtained from repositories maintained by IRIS (Incorporated Research Institutions for Seismology) at the Data Management Center, Seattle Washington. Suppose a seismologist wants to examine data gathered when an earthquake measuring 7.2 on the Richter scale hit Turkey on October 31,1998. Wiggleview displays data at 20 stations for this event. The tool's strength lies in being able to depict as many as 60 channels of waveforms and 20 traces of particle motion on a single display. This allows one to watch the seismic wave field expand about a source and see how it differs from place to place. It can also assist in understanding surface wave multipathing and anisotropy -- this is important for revealing structure and for seismic hazard estimation. Wiggleview was designed for two display platforms: the standard PC-based desktop or laptop with a modern-day game graphics card; and a stereoscopic projection system called the Geowall. The stereoscopic nature of the images enhances depth perception and thus allows better understanding of attenuation due to distance and earth structure, source directivity and seismic hazard estimation. Illustrations are available at the Wiggleview website http://www.evl.uic.edu/atul/wiggleview

  12. PSMG switchgear seismic analysis

    International Nuclear Information System (INIS)

    Kuehster, C.J.

    1977-01-01

    LOFT primary coolant system motor generator (PSMG) switchgear boxes were analyzed for sliding and overturning during a seismic event. Boxes are located in TAN-650, Room B-239, with the PSMG generators. Both boxes are sufficiently anchored to the floor

  13. R-process enrichment from a single event in an ancient dwarf galaxy.

    Science.gov (United States)

    Ji, Alexander P; Frebel, Anna; Chiti, Anirudh; Simon, Joshua D

    2016-03-31

    Elements heavier than zinc are synthesized through the rapid (r) and slow (s) neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of trends in chemical abundances in old Milky Way halo stars suggested that these elements are produced continually, in sites such as core-collapse supernovae. But evidence from the local Universe favours the idea that r-process production occurs mainly during rare events, such as neutron star mergers. The appearance of a plateau of europium abundance in some dwarf spheroidal galaxies has been suggested as evidence for rare r-process enrichment in the early Universe, but only under the assumption that no gas accretes into those dwarf galaxies; gas accretion favours continual r-process enrichment in these systems. Furthermore, the universal r-process pattern has not been cleanly identified in dwarf spheroidals. The smaller, chemically simpler, and more ancient ultrafaint dwarf galaxies assembled shortly after the first stars formed, and are ideal systems with which to study nucleosynthesis events such as the r-process. Reticulum II is one such galaxy. The abundances of non-neutron-capture elements in this galaxy (and others like it) are similar to those in other old stars. Here, we report that seven of the nine brightest stars in Reticulum II, observed with high-resolution spectroscopy, show strong enhancements in heavy neutron-capture elements, with abundances that follow the universal r-process pattern beyond barium. The enhancement seen in this 'r-process galaxy' is two to three orders of magnitude higher than that detected in any other ultrafaint dwarf galaxy. This implies that a single, rare event produced the r-process material in Reticulum II. The r-process yield and event rate are incompatible with the source being ordinary core-collapse supernovae, but consistent with other possible sources, such as neutron star mergers.

  14. Compendium of Single-Event Latchup and Total Ionizing Dose Test Results of Commercial Analog to Digital Converters

    Science.gov (United States)

    Irom, Farokh; Agarwal, Shri G.

    2012-01-01

    This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.

  15. Single event upsets calculated from new ENDF/B-VI proton and neutron data up to 150 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B. [Los Alamos National Lab., NM (United States). Theoretical Div.; Normand, E. [Boeing Military Aircraft and Missile Systems, Seattle, WA (United States)

    1999-06-01

    Single-event upsets (SEU) in microelectronics are calculated from newly-developed silicon nuclear reaction recoil data that extend up to 150 MeV, for incident protons and neutrons. Calculated SEU cross sections are compared with measured data.

  16. Characterization of System Level Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

    Science.gov (United States)

    Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

    2017-01-01

    We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

  17. Single-Event Effect Testing of the Cree C4D40120D Commercial 1200V Silicon Carbide Schottky Diode

    Science.gov (United States)

    Lauenstein, J.-M.; Casey, M. C.; Wilcox, E. P.; Kim, Hak; Topper, A. D.

    2014-01-01

    This study was undertaken to determine the single event effect (SEE) susceptibility of the commercial silicon carbide 1200V Schottky diode manufactured by Cree, Inc. Heavy-ion testing was conducted at the Texas A&M University Cyclotron Single Event Effects Test Facility (TAMU). Its purpose was to evaluate this device as a candidate for use in the Solar-Electric Propulsion flight project.

  18. Single-event multilevel surgery in children with spastic diplegia: a pilot randomized controlled trial.

    Science.gov (United States)

    Thomason, Pamela; Baker, Richard; Dodd, Karen; Taylor, Nicholas; Selber, Paulo; Wolfe, Rory; Graham, H Kerr

    2011-03-02

    Single-event multilevel surgery is considered the standard of care to improve gait and functioning of children with spastic diplegic cerebral palsy. However, the evidence base is limited. This pilot study is the first randomized controlled trial of single-event multilevel surgery, to our knowledge. Nineteen children (twelve boys and seven girls with a mean age of nine years and eight months) with spastic diplegia were enrolled. Eleven children were randomized to the surgical group and eight, to the control group. The control group underwent a program of progressive resistance strength training. The randomized phase of the trial concluded at twelve months. The control group then exited the study and progressed to surgery, whereas the surgical group continued to be followed in a prospective cohort study. The primary outcome measures were the Gait Profile Score (GPS) and the Gillette Gait Index (GGI). Secondary outcome measures were gross motor function (Gross Motor Function Measure-66 [GMFM-66]), functional mobility (Functional Mobility Scale [FMS]), time spent in the upright position, and health-related quality of life (Child Health Questionnaire [CHQ]). A total of eighty-five surgical procedures were performed, with a mean of eight procedures per child (standard deviation, four). The surgical group had a 34% improvement in the GPS and a 57% improvement in the GGI at twelve months. The control group had a small nonsignificant deterioration in both indices. The between-group differences for the change in the GPS (-5.5; 95% confidence interval, -7.6 to -3.4) and the GGI (-218; 95% confidence interval, -299 to -136) were highly significant. The differences between the groups with regard to the secondary outcome measures were not significant at twelve months. At twenty-four months after surgery, there was a 4.9% increase in the GMFM-66 score and improvements in the FMS score, time spent in the upright position, and the physical functioning domain of the CHQ in the

  19. Observation of Single Isolated Electrons of High Transverse Momentum in Events with Missing Transverse Energy at the CERN pp Collider

    DEFF Research Database (Denmark)

    Banner, M.; Kofoed-Hansen, O.

    1983-01-01

    We report the results of a search for single isolated electrons of high transverse momentum at the CERN collider. Above 15 GeV/c, four events are found having large missing transverse energy along a direction opposite in azimuth to that of the high-pT electron. Both the configuration of the events...

  20. Mixed response and time-to-event endpoints for multistage single-arm phase II design.

    Science.gov (United States)

    Lai, Xin; Zee, Benny Chung-Ying

    2015-06-04

    The objective of phase II cancer clinical trials is to determine if a treatment has sufficient activity to warrant further study. The efficiency of a conventional phase II trial design has been the object of considerable debate, particularly when the study regimen is characteristically cytostatic. At the time of development of a phase II cancer trial, we accumulated clinical experience regarding the time to progression (TTP) for similar classes of drugs and for standard therapy. By considering the time to event (TTE) in addition to the tumor response endpoint, a mixed-endpoint phase II design may increase the efficiency and ability of selecting promising cytotoxic and cytostatic agents for further development. We proposed a single-arm phase II trial design by extending the Zee multinomial method to fully use mixed endpoints with tumor response and the TTE. In this design, the dependence between the probability of response and the TTE outcome is modeled through a Gaussian copula. Given the type I and type II errors and the hypothesis as defined by the response rate (RR) and median TTE, such as median TTP, the decision rules for a two-stage phase II trial design can be generated. We demonstrated through simulation that the proposed design has a smaller expected sample size and higher early stopping probability under the null hypothesis than designs based on a single-response endpoint or a single TTE endpoint. The proposed design is more efficient for screening new cytotoxic or cytostatic agents and less likely to miss an effective agent than the alternative single-arm design.

  1. Single event upset studies on the CMS tracker APV25 readout chip

    CERN Document Server

    Noah, E; Bisello, D; Faccio, F; Friedl, M; Fulcher, J R; Hall, G; Huhtinen, M; Kaminski, A; Pernicka, Manfred; Raymond, M; Wyss, J

    2002-01-01

    The microstrip tracker for the CMS experiment at the CERN Large Hadron Collider will be read out using APV25 chips. During high luminosity running the tracker will be exposed to particle fluxes up to 10**7 cm**-**2 s**-**1, which raises concerns that the APV25 could occasionally suffer Single Event Upsets (SEUs). The effect of SEU on the APV25 has been studied to investigate implications for CMS detector operation and from the viewpoint of detailed circuit operation, to improve the understanding of its origin and what factors affect its magnitude. Simulations were performed to reconstruct the effects created by highly ionising particles striking sensitive parts of the circuits, along with consideration of the underlying mechanisms of charge deposition, collection and the consequences. A model to predict the behaviour of the memory circuits in the APV25 has been developed and data collected from dedicated experiments using both heavy ions and hadrons have been shown to support it.

  2. Talys calculations for evaluation of neutron-induced single-event upset cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Bourselier, Jean-Christophe

    2005-08-15

    The computer code TALYS has been used to calculate interactions between cosmic-ray neutrons and silicon nuclei with the goal to describe single-event upset (SEU) cross sections in microelectronics devices. Calculations for the Si(n,X) reaction extend over an energy range of 2 to 200 MeV. The obtained energy spectra of the resulting residuals and light-ions have been integrated using several different critical charges as SEU threshold. It is found that the SEU cross section seems largely to be dominated by {sup 28}Si recoils from elastic scattering. Furthermore, the shape of the SEU cross section as a function of the energy of the incoming neutron changes drastically with decreasing critical charge. The results presented in this report stress the importance of performing studies at mono-energetic neutron beams to advance the understanding of the underlying mechanisms causing SEUs.

  3. Screening of nanosatellite microprocessors using californium single-event latch-up test results

    Science.gov (United States)

    Tomioka, Takahiro; Okumura, Yuta; Masui, Hirokazu; Takamiya, Koichi; Cho, Mengu

    2016-09-01

    A single-event latch-up (SEL) test using a 252Cf radioisotope was carried out. The results were compared with those of a proton test and from observation in orbit. A radioisotope can reproduce phenomena observed in orbit that are caused by protons. Considering the inexpensive nature of the 252Cf test, it is more suitable for nanosatellites that require low cost and fast delivery. A SEL occurrence rate of a commercial-off-the-shelf microprocessor was derived from the ground test results. The 252Cf test provided a SEL rate approximately 1×106 times greater than that in orbit. This data can be used to derive the minimum SEL occurrence rate in orbit and help satellite designers to evaluate the risk of SEL and take measures if necessary.

  4. Experimental study on the single event effects in pulse width modulators by laser testing

    International Nuclear Information System (INIS)

    Zhao Wen; Guo Xiaoqiang; Chen Wei; Guo Hongxia; Lin Dongsheng; Luo Yinhong; Ding Lili; Wang Yuanming; Wang Hanning

    2015-01-01

    This paper presents single event effect (SEE) characteristics of UC1845AJ pulse width modulators (PWMs) by laser testing. In combination with analysis to map PWM circuitry in the microchip dies, the typical SEE response waveforms for laser pulses located in different circuit blocks of UC1845AJ are obtained and the SEE mechanisms are analyzed. The laser SEE test results show that there are some differences in the SEE mechanisms of different circuit blocks, and phase shifts or changes in the duty cycles of few output pulses are the main SEE behaviors for UC1845AJ. In addition, a new SEE behavior which manifests as changes in the duty cycles of many output pulses is revealed. This means that an SEE hardened design should be considered. (paper)

  5. Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

    CERN Document Server

    García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

    Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

  6. Single Event Effect cross section calibration and application to quasi-monoenergetic and spallation facilities

    Directory of Open Access Journals (Sweden)

    Alía Rubén García

    2018-01-01

    Full Text Available We describe an approach to calibrate Single Event Effect (SEE-based detectors in monoenergetic fields and apply the resulting semi-empiric responses to more general mixed-field cases in which a broad variety of particle species and energy spectra are present. The calibration of the response functions is based both on experimental proton (30–200 MeV and neutron (5–300 MeV data and considerations derived from Monte Carlo simulations using the FLUKA Monte Carlo code. The application environments include the quasi-monoenergetic neutrons at RCNP, the atmospheric-like VESUVIO spallation spectrum and the CHARM high-energy accelerator test facility. The agreement between the mixed-field response and that predicted through the mono-energetic calibration is within ±30% for the broad variety of cases considered and thus regarded as highly successful for mixed-field monitoring applications.

  7. Simulation study on single event burnout in linear doping buffer layer engineered power VDMOSFET

    International Nuclear Information System (INIS)

    Jia Yunpeng; Su Hongyuan; Hu Dongqing; Wu Yu; Jin Rui

    2016-01-01

    The addition of a buffer layer can improve the device's secondary breakdown voltage, thus, improving the single event burnout (SEB) threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an optimized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer layer. So the linear buffer layer is more advantageous to improving the device's SEB performance. (paper)

  8. Single event upset in static random access memories in atmospheric neutron environments

    CERN Document Server

    Arita, Y; Ogawa, I; Kishimoto, T

    2003-01-01

    Single-event upsets (SEUs) in a 0.4 mu m 4Mbit complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) were investigated in various atmospheric neutron environments at sea level, at an altitude of 2612 m mountain, at an altitude of commercial airplane, and at an underground depth of 476m. Neutron-induced SEUs increase with the increase in altitude. For a device with a borophosphosilicate glass (BPSG) film, SEU rates induced by thermal neutrons increase with the decrease in the cell charge of a memory cell. A thermal neutron-induced SEU is significant in SRAMs with a small cell charge. With the conditions of small cell charge, thermal neutron-induced SEUs account for 60% or more of the total neutron-induced SEUs. The SEU rate induced by atmospheric thermal neutrons can be estimated by an acceleration test using sup 2 sup 5 sup 2 Cf. (author)

  9. Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, V.A.P. [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Added, N., E-mail: nemitala@if.usp.br [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Medina, N.H.; Macchione, E.L.A.; Tabacniks, M.H.; Aguirre, F.R. [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Silveira, M.A.G.; Santos, R.B.B. [Centro Universitário da FEI, São Bernardo do Campo, SP (Brazil); Seixas, L.E. [Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil)

    2014-08-01

    In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. {sup 12}C, {sup 16}O, {sup 28}Si, {sup 35}Cl and {sup 63}Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm{sup 2} for an external beam arrangement and up to 32 MeV/mg/cm{sup 2} for in-vacuum irradiation.

  10. Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

    Science.gov (United States)

    Aguiar, V. A. P.; Added, N.; Medina, N. H.; Macchione, E. L. A.; Tabacniks, M. H.; Aguirre, F. R.; Silveira, M. A. G.; Santos, R. B. B.; Seixas, L. E.

    2014-08-01

    In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. 12C, 16O, 28Si, 35Cl and 63Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm2 for an external beam arrangement and up to 32 MeV/mg/cm2 for in-vacuum irradiation.

  11. Acquisition and classification of static single-event upset cross section for SRAM-based FPGAs

    International Nuclear Information System (INIS)

    Yao Zhibin; Fan Ruyu; Guo Hongxia; Wang Zhongming; He Baoping; Zhang Fengqi; Zhang Keying

    2011-01-01

    In order to evaluate single event upsets (SEUs) in SRAM-based FPGAs and to find the sensitive resource in configuration memory, a heavy ions irradiation experiment was carried out on a Xilinx FPGAs device XCV300PQ240. The experiment was conducted to gain the static SEU cross section and classify the SEUs in configurations memory according to different resource uses. The results demonstrate that the inter-memory of SRAM-based FPGAs is extremely sensitive to heavy-ion-induced SEUs. The LUT and routing resources are the main source of SEUs in the configuration memory, which covers more than 97.46% of the total upsets. The SEU sensitivity of various resources is different. The IOB control bit and LUT elements are more sensitive,and more attention should be paid to the LUT elements in radiation hardening,which account for a quite large proportion of the configuration memory. (authors)

  12. Neutron-induced single event upsets in static RAMs observed at 10 KM flight altitude

    Science.gov (United States)

    Olsen, J.; Becher, P. E.; Fynbo, P. B.; Raaby, P.; Schultz, J.

    1993-04-01

    Neutron induced single event upsets (SEUs) in static memory devices (SRAMs) have so far been seen only in laboratory environments. We report observations of 14 neutron induced SEUs at commercial aircraft flight altitudes. The observed SEU rate at 10 km flight altitude based on exposure of 160 standard 256 Kbit CMOS SRAMs is 4.8 x 10 exp -8 upsets/bit/day. In the laboratory 117 SRAMs of two different brands were irradiated with fast neutrons from a Pu-Be source. A total of 176 SEUs have been observed, among these are two SEU pairs. The upset rates from the laboratory tests are compared to those found in the airborne SRAMs.

  13. Spatial-Temporal Feature Analysis on Single-Trial Event Related Potential for Rapid Face Identification

    Directory of Open Access Journals (Sweden)

    Lei Jiang

    2017-11-01

    Full Text Available The event-related potential (ERP is the brain response measured in electroencephalography (EEG, which reflects the process of human cognitive activity. ERP has been introduced into brain computer interfaces (BCIs to communicate the computer with the subject's intention. Due to the low signal-to-noise ratio of EEG, most ERP studies are based on grand-averaging over many trials. Recently single-trial ERP detection attracts more attention, which enables real time processing tasks as rapid face identification. All the targets needed to be retrieved may appear only once, and there is no knowledge of target label for averaging. More interestingly, how the features contribute temporally and spatially to single-trial ERP detection has not been fully investigated. In this paper, we propose to implement a local-learning-based (LLB feature extraction method to investigate the importance of spatial-temporal components of ERP in a task of rapid face identification using single-trial detection. Comparing to previous methods, LLB method preserves the nonlinear structure of EEG signal distribution, and analyze the importance of original spatial-temporal components via optimization in feature space. As a data-driven methods, the weighting of the spatial-temporal component does not depend on the ERP detection method. The importance weights are optimized by making the targets more different from non-targets in feature space, and regularization penalty is introduced in optimization for sparse weights. This spatial-temporal feature extraction method is evaluated on the EEG data of 15 participants in performing a face identification task using rapid serial visual presentation paradigm. Comparing with other methods, the proposed spatial-temporal analysis method uses sparser (only 10% of the total features, and could achieve comparable performance (98% of single-trial ERP detection as the whole features across different detection methods. The interesting finding is

  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. Long term outcome of single event multilevel surgery in spastic diplegia with flexed knee gait.

    Science.gov (United States)

    Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Akhmedov, Bekhzad; Lee, Seung Yeol; Choi, In Ho; Cho, Tae-Joon; Yoo, Won Joon; Park, Moon Seok

    2013-04-01

    Distal hamstring lengthening (DHL) is a commonly performed procedure in flexed knee gait. However, the necessity of this procedure has been challenged due to the concerns on adverse effects in long-term follow-up. This retrospective study was undertaken to investigate the long-term outcome of single event multilevel surgery (SEMLS), including bilateral DHL, in ambulatory patients with cerebral palsy using 3D gait analysis. Twenty-nine ambulatory patients with spastic diplegic cerebral palsy who had undergone SEMLS including bilateral DHL were included. 3D gait analysis was performed preoperatively, 1 year postoperatively and over 10 years postoperatively. Preoperative temporal parameters, kinematics and GDI were compared with values obtained 1 and 10 year follow-up visits. The mean age of patients at time of first surgery was 8.3 years (range, 5.4-16.3 years), and mean time from first surgery to last 3D gait analysis was 11.8 years (range, 10.0-13.3 years). Mean pelvic tilt was not changed significantly after SEMLS including DHL. Mean knee flexion at initial contact decreased from 31.1° preoperatively to 26.0° at 1 year postoperatively (p=0.065), and then decreased significantly to 23.6° at 10 years postoperatively (p=0.038) versus the preoperative value. Mean GDI score significantly improved from 69.4 preoperatively to 77.9 at 1 year postoperatively (p=0.003) and continuously improved to 82.2 at 10 years postoperatively (p=0.017). Single event multilevel surgery including DHL provides a favorable outcome 10 years postoperatively in patients with spastic diplegic cerebral palsy. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. A detector system for studying nuclear reactions relevant to Single Event Effects

    Energy Technology Data Exchange (ETDEWEB)

    Murin, Yu. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation)]. E-mail: murin@jinr.ru; Babain, Yu. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation); Chubarov, M. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation); Tuboltsev, Yu. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation); Pljuschev, V. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation); Zubkov, M. [V.G. Khlopin Radium Institute, 2nd Murinski 28, 194021 St. Petersburg (Russian Federation); Nomokonov, P. [High Energy Laboratory, Joint Institute for Nuclear Research, 141980 Moscow Region (Russian Federation); Voronin, A. [Moscow State University, 119992 Moscow (Russian Federation); Merkin, M. [Moscow State University, 119992 Moscow (Russian Federation); Kondratiev, V. [St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Olsson, N.; Blomgren, J. [Department of Neutron Research, Uppsala University, Box 525, SE 751 20 Uppsala (Sweden); Westerberg, L. [Department of Physics, Uppsala University, Box 530, SE 751 21 Uppsala (Sweden); Ekstroem, C.; Kolozhvari, A. [The Svedberg Laboratory, Uppsala University, Box 533, SE 751 21 Uppsala (Sweden); Jaederstroem, H. [Department of Nuclear and Particle Physics, Uppsala University, Box 531, SE 751 21 Uppsala (Sweden); Jakobsson, B.; Golubev, P. [Department of Physics, Lund University, Box 118, SE 221 00 Lund (Sweden); Bargholz, Chr.; Geren, L.; Tegner, P.-E.; Zartova, I. [Department of Physics, Stockholm University, AlbaNova, SE 10691 Stockholm (Sweden); Budzanowski, A.; Czech, B.; Skwirczynska, I. [H. Niewodniczanski Institute of Nuclear Physics, PL 31 342 Cracow (Poland); Tang, H.H.K. [IBM, T.J. Watson Research Center, Yorktown Heights, NY 10598 (United States)

    2007-08-01

    We describe a device to study reactions relevant for the Single Event Effect (SEE) in microelectronics by means of 200A and 300AMeV, inverse kinematics, Si+H and Si+D reactions. The work is focused on the possibility to measure Z=2-14 projectile fragments as efficiently as possible. During commissioning and first experiments the fourth quadrant of the CELSIUS storage ring acted as a spectrometer to register fragments in two planes of Si strip detectors in the angular region 0{sup a}t -0.6{sup a}t. A combination of ring-structured and sector-structured Si strip detector planes operated at angles 0.6{sup a}t-1.1{sup a}t. For specific event tagging a Si+ phoswich scintillator wall operated in the range 3.9{sup a}t-11.7{sup a}t and Si {delta}E-E telescopes of CHICSi type operated at large angles.

  17. 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.

  18. Use of Solid Waste (Foundry Slag) Mortar and Bamboo Reinforcement in Seismic Analysis for Single Storey Masonry Building

    Science.gov (United States)

    Ahmad, S.; Husain, A.; Ghani, F.; Alam, M. N.

    2013-11-01

    The conversion of large amount of solid waste (foundry slag) into alternate source of building material will contribute not only as a solution to growing waste problem, but also it will conserve the natural resources of other building material and thereby reduce the cost of construction. The present work makes an effort to safe and economic use of recycle mortar (1:6) as a supplementary material. Conventional and recycled twelve prisms were casted with varying percentage of solid waste (foundry slag) added (0, 10, 20, 30 %) replacing cement by weight and tested under compression testing machine. As the replacement is increasing, the strength is decreasing. 10 % replacement curve is very closed to 0 % whereas 20 % is farther and 30 % is farthest. 20 % replacement was chosen for dynamic testing as its strength is within permissible limit as per IS code. A 1:4 scale single storey brick model with half size brick was fabricated on shake table in the lab for dynamic testing using pure friction isolation system (coarse sand as friction material µ = 0.34). Pure friction isolation technique can be adopted economically in developing countries where low-rise building prevails due to their low cost. The superstructure was separated from the foundation at plinth level, so as to permit sliding of superstructure during severe earthquake. The observed values of acceleration and displacement responses compare fairly with the analytical values of the analytical model. It also concluded that 20 % replacement of cement by solid waste (foundry slag) could be safely adopted without endangering the safety of the masonry structures under seismic load.To have an idea that how much energy is dissipated through this isolation, the same model with fixed base was tested and results were compared with the isolated free sliding model and it has been observed that more than 60 % energy is dissipated through this pure friction isolation technique. In case of base isolation, no visible cracks

  19. Single charging events on colloidal particles in a nonpolar liquid with surfactant

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Brans, Toon; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-01-01

    Electrical charging of colloidal particles in nonpolar liquids due to surfactant additives is investigated intensively, motivated by its importance in a variety of applications. Most methods rely on average electrophoretic mobility measurements of many particles, which provide only indirect information on the charging mechanism. In the present work, we present a method that allows us to obtain direct information on the charging mechanism, by measuring the charge fluctuations on individual particles with a precision higher than the elementary charge using optical trapping electrophoresis. We demonstrate the capabilities of the method by studying the influence of added surfactant OLOA 11000 on the charging of single colloidal PMMA particles in dodecane. The particle charge and the frequency of charging events are investigated both below and above the critical micelle concentration (CMC) and with or without applying a DC offset voltage. It is found that at least two separate charging mechanisms are present below the critical micelle concentration. One mechanism is a process where the particle is stripped from negatively charged ionic molecules. An increase in the charging frequency with increased surfactant concentration suggests a second mechanism that involves single surfactant molecules. Above the CMC, neutral inverse micelles can also be involved in the charging process.

  20. Single-Trial Event-Related Potential Based Rapid Image Triage System

    Directory of Open Access Journals (Sweden)

    Ke Yu

    2011-06-01

    Full Text Available Searching for points of interest (POI in large-volume imagery is a challenging problem with few good solutions. In this work, a neural engineering approach called rapid image triage (RIT which could offer about a ten-fold speed up in POI searching is developed. It is essentially a cortically-coupled computer vision technique, whereby the user is presented bursts of images at a speed of 6–15 images per second and then neural signals called event-related potential (ERP is used as the ‘cue’ for user seeing images of high relevance likelihood. Compared to past efforts, the implemented system has several unique features: (1 it applies overlapping frames in image chip preparation, to ensure rapid image triage performance; (2 a novel common spatial-temporal pattern (CSTP algorithm that makes use of both spatial and temporal patterns of ERP topography is proposed for high-accuracy single-trial ERP detection; (3 a weighted version of probabilistic support-vector-machine (SVM is used to address the inherent unbalanced nature of single-trial ERP detection for RIT. High accuracy, fast learning, and real-time capability of the developed system shown on 20 subjects demonstrate the feasibility of a brainmachine integrated rapid image triage system for fast detection of POI from large-volume imagery.

  1. Single photon and multiphoton events with missing energy in $e^{+} e^{-}$ collisions at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosenbleck, C; Rosier-Lees, S; Roth, S; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2004-01-01

    Single- and multi-photon events with missing energy are selected in 619/pb of data collected by the L3 detector at LEP at centre-of-mass energies between 189GeV and 209GeV. The cross sections of the process e^+e^- -> nu nu gamma (gamma) are found to be in agreement with the Standard Model expectations, and the number of light neutrino species is determined, including lower energy data, to be N_nu = 2.98 +/- 0.05 +/- 0.04. Selection results are also given in the form of tables which can be used to test future models involving single- and multi-photon signatures at LEP. These final states are also predicted by models with large extra dimensions and by several supersymmetric models. No evidence for such models is found. Among others, lower limits between 1.5TeV and 0.65TeV are set, at 95% confidence level, on the new scale of gravity for the number of extra dimensions between 2 and 8.

  2. Modeling of Single Event Transients With Dual Double-Exponential Current Sources: Implications for Logic Cell Characterization

    Science.gov (United States)

    Black, Dolores A.; Robinson, William H.; Wilcox, Ian Z.; Limbrick, Daniel B.; Black, Jeffrey D.

    2015-08-01

    Single event effects (SEE) are a reliability concern for modern microelectronics. Bit corruptions can be caused by single event upsets (SEUs) in the storage cells or by sampling single event transients (SETs) from a logic path. An accurate prediction of soft error susceptibility from SETs requires good models to convert collected charge into compact descriptions of the current injection process. This paper describes a simple, yet effective, method to model the current waveform resulting from a charge collection event for SET circuit simulations. The model uses two double-exponential current sources in parallel, and the results illustrate why a conventional model based on one double-exponential source can be incomplete. A small set of logic cells with varying input conditions, drive strength, and output loading are simulated to extract the parameters for the dual double-exponential current sources. The parameters are based upon both the node capacitance and the restoring current (i.e., drive strength) of the logic cell.

  3. Optical seismic sensor systems and methods

    Science.gov (United States)

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun

    2015-12-08

    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  4. Good practices for the operational safety management in the early recovery phase of a seismic event using GPR

    Science.gov (United States)

    Bianchini Ciampoli, Luca; Giulia Brancadoro, Maria; Benedetto, Andrea; D'Amico, Fabrizio; Calvi, Alessandro; Alani, Amir M.; Tosti, Fabio

    2017-04-01

    This study deals with a case report about the planning and the performance of GPR surveys carried out in the town of Amatrice, in the district of Rieti, Italy. As sadly known, the town has been hit by a 6.9 magnitude earthquake in the nighttime of August 24th 2016. The strength of the seism, along with the age and the deterioration rate of the structural asset, have caused the razing to the ground and the critical damaging of the majority of the buildings within the "red zone area", corresponding to the historical town center. In the early recovery phase taking place afterwards, the strong seismic swarm subsequent the main shake has sensitively slowed down the rescue and rehabilitation operations. Moreover, the main issue was related to the unsafety operational conditions of volunteers and firemen. To this effect, the geotechnical stability of the roads and the large operational areas represented critical issues, as up to 40 tons crane trucks were needed to put in safety the highest buildings, such as three-floor buildings and historical towers. In this framework, ground-penetrating radar (GPR) provided a valuable help in preliminary assessing the stability of the areas where the crane trucks were planned to operate as well as to be parked over. The main objective of the GPR tests was to verify the absence of possible cavities beneath the ground surface that could undermine the strength of the surface under heavy loadings. To that effect, a multi-frequency ground-coupled GPR system was used. This radar system can simultaneously collect data at both the frequencies of 600 MHz and 1600 MHz. Four different sites were surveyed, namely, two sections of the main road passed on by the cranes, and two machinery depot areas down by the towers. In the former case, the surveys were performed by parallel longitudinal scans, due to the significant longitudinal length of the sections, whereas in the latter, two grids with differing sizes were realized and scanned for producing

  5. Long-period events, the most characteristic seismicity accompanying the emplacement and extrusion of a lava dome in Galeras Volcano, Colombia, in 1991

    Science.gov (United States)

    Gil, Cruz F.; Chouet, B.A.

    1997-01-01

    Since its reactivation in 1988 the principal eruptions of Galeras Volcano occurred on May 4-9, 1989, July 16, 1992, and January 14, March 23, April 3, April 14 and June 7, 1993. The initial eruption was a phreatic event which clearly marked a new period of activity. A lava dome was extruded within the main crater in October 1991 and subsequently destroyed in an explosive eruption on July 16, 1992. The eruptions that followed were all vulcanian-type explosions. The seismicity accompanying the emplacement, extrusion, and destruction of the lava dome was dominated by a mix of long-period (LP) events and tremor displaying a variety of waveforms. Repetitive LP events with dominant periods in the range 0.2-1 s were observed in October and November 1991 and visually correlated with short energetic pulses of gas venting through a crack bisecting the dome surface. Each LP event was characterized by a weak precursory signal with dominant periods in the range 0.05-0.1 s lasting roughly 7 s. Using the fluid-driven crack model of Chouet (1988, 1992), we infer that two distinct cracks may have acted as sources for the LP and precursor signals. Spectral analyses of the data yield the following parameters for the LP source: crack length, 240-360 m; crack width, 130-150 m; crack aperture, 0.5-3.4 mm; crack stiffness, 100-500; sound speed of fluid, 880 m/s; and excess pressure, 0.01-0.19 MPa. Similar analyses yield the parameters of the precursor source: crack length, 20-30 m; crack width, 15-25 m; crack aperture, 2.3-8.7 mm; crack stiffness, 5-15; sound speed of fluid, 140 m/s; and excess pressure, 0.06-0.15 MPa. Combined with geologic and thermodynamic constraints obtained from field observations, these seismic parameters suggest a gas-release mechanism in which the episodic collapse of a foam layer trapped at the top of the magma column subjacent to the dome releases a slug of pressurized gas which escapes to the surface while dilating a preexisting system of cracks in the dome

  6. A model of characteristic earthquakes and its implications for regional seismicity

    DEFF Research Database (Denmark)

    López-Ruiz, R.; Vázquez-Prada, M.; Pacheco, A.F.

    2004-01-01

    Regional seismicity (i.e. that averaged over large enough areas over long enough periods of time) has a size-frequency relationship, the Gutenberg-Richter law, which differs from that found for some seismic faults, the Characteristic Earthquake relationship. But all seismicity comes in the end from...... active faults, so the question arises of how one seismicity pattern could emerge from the other. The recently introduced Minimalist Model of Vázquez-Prada et al. of characteristic earthquakes provides a simple representation of the seismicity originating from a single fault. Here, we show...... that a Characteristic Earthquake relationship together with a fractal distribution of fault lengths can accurately describe the total seismicity produced in a region. The resulting earthquake catalogue accounts for the addition of both all the characteristic and all the non-characteristic events triggered in the faults...

  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. Antarctic ice sheet thickness estimation using the horizontal-to-vertical spectral ratio method with single-station seismic ambient noise

    Science.gov (United States)

    Yan, Peng; Li, Zhiwei; Li, Fei; Yang, Yuande; Hao, Weifeng; Bao, Feng

    2018-03-01

    We report on a successful application of the horizontal-to-vertical spectral ratio (H / V) method, generally used to investigate the subsurface velocity structures of the shallow crust, to estimate the Antarctic ice sheet thickness for the first time. Using three-component, five-day long, seismic ambient noise records gathered from more than 60 temporary seismic stations located on the Antarctic ice sheet, the ice thickness measured at each station has comparable accuracy to the Bedmap2 database. Preliminary analysis revealed that 60 out of 65 seismic stations on the ice sheet obtained clear peak frequencies (f0) related to the ice sheet thickness in the H / V spectrum. Thus, assuming that the isotropic ice layer lies atop a high velocity half-space bedrock, the ice sheet thickness can be calculated by a simple approximation formula. About half of the calculated ice sheet thicknesses were consistent with the Bedmap2 ice thickness values. To further improve the reliability of ice thickness measurements, two-type models were built to fit the observed H / V spectrum through non-linear inversion. The two-type models represent the isotropic structures of single- and two-layer ice sheets, and the latter depicts the non-uniform, layered characteristics of the ice sheet widely distributed in Antarctica. The inversion results suggest that the ice thicknesses derived from the two-layer ice models were in good concurrence with the Bedmap2 ice thickness database, and that ice thickness differences between the two were within 300 m at almost all stations. Our results support previous finding that the Antarctic ice sheet is stratified. Extensive data processing indicates that the time length of seismic ambient noise records can be shortened to two hours for reliable ice sheet thickness estimation using the H / V method. This study extends the application fields of the H / V method and provides an effective and independent way to measure ice sheet thickness in Antarctica.

  9. Risk assessment of K Basin twelve-inch and four-inch drain valve failure from a postulated seismic initiating event

    Energy Technology Data Exchange (ETDEWEB)

    MORGAN, R.G.

    1999-06-23

    The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rate which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. Five four-inch drain valves are located in the north and south loadout pits (NLOP and SLOP), the weasel pit, the technical viewing pit, and the discharge chute pit. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations indicate that only the valve's bonnet and stem are exposed above the basin concrete floor for the twelve-inch drain valve and that much less of the valve's bonnet and stem are exposed above the basin concrete floor for the five four-inch drain valves. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this analysis are to: (1) evaluate the likelihood of damaging the three twelve-inch drain valves located along the north wall of the main basin and the five four-inch drain valves located in the pits from a seismic initiating event, and (2) determine the likelihood of exceeding a specific consequence (initial leak rate) from a damaged valve. The analysis process is a risk-based uncertainty analysis where each variable is modeled using available information and engineering judgement. The uncertainty associated with each variable is represented by a probability distribution (probability density function). Uncertainty exists because of the inherent

  10. Single-event multilevel surgery for children with cerebral palsy: a systematic review.

    Science.gov (United States)

    McGinley, Jennifer L; Dobson, Fiona; Ganeshalingam, Rekha; Shore, Benjamin J; Rutz, Erich; Graham, H Kerr

    2012-02-01

    To conduct a systematic review of single-event multilevel surgery (SEMLS) for children with cerebral palsy, with the aim of evaluating the quality of the evidence and developing recommendations for future research. The systematic review was conducted using standard search and extraction methods in Medline, EMBASE, CINAHL, and Cochrane electronic databases. For the purposes of this review, SEMLS was defined as two or more soft-tissue or bony surgical procedures at two or more anatomical levels during one operative procedure, requiring only one hospital admission and one period of rehabilitation. Studies were included if: (1) the primary focus was to examine the effect of SEMLS in children with cerebral palsy; (2) the results focused on multiple anatomic levels and reported findings of one or more World Health Organization International Classification of Functioning, Disability and Health (ICF) domains. Studies that focused on a single intervention or level, or on the utility of a specific outcome measure were excluded. Study quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) and the Oxford Centre for Evidence-Based Medicine scale. The review also examined the reporting of surgery, adverse events, and rehabilitation. Thirty-one studies fulfilled the criteria for inclusion, over the period 1985 to October 2010. The MINORS score for these studies varied from 4 to 19, with marked variation in the quality of reporting. Study quality has improved over recent years. Valid measures of gait and function have been introduced and several of the most recent studies have addressed multiple dimensions of the ICF. A statistical synthesis of the outcome data was not conducted, although a trend towards favourable outcomes in gait was evident. Caution is advised with interpretation owing to the variable study quality. Uncontrolled studies may have resulted in an overestimation of treatment efficacy. The design and reporting of studies of SEMLS are

  11. Single-Trial Event-Related Potential Correlates of Belief Updating

    Science.gov (United States)

    Murawski, Carsten; Bode, Stefan

    2015-01-01

    Abstract Belief updating—the process by which an agent alters an internal model of its environment—is a core function of the CNS. Recent theory has proposed broad principles by which belief updating might operate, but more precise details of its implementation in the human brain remain unclear. In order to address this question, we studied how two components of the human event-related potential encoded different aspects of belief updating. Participants completed a novel perceptual learning task while electroencephalography was recorded. Participants learned the mapping between the contrast of a dynamic visual stimulus and a monetary reward and updated their beliefs about a target contrast on each trial. A Bayesian computational model was formulated to estimate belief states at each trial and was used to quantify the following two variables: belief update size and belief uncertainty. Robust single-trial regression was used to assess how these model-derived variables were related to the amplitudes of the P3 and the stimulus-preceding negativity (SPN), respectively. Results showed a positive relationship between belief update size and P3 amplitude at one fronto-central electrode, and a negative relationship between SPN amplitude and belief uncertainty at a left central and a right parietal electrode. These results provide evidence that belief update size and belief uncertainty have distinct neural signatures that can be tracked in single trials in specific ERP components. This, in turn, provides evidence that the cognitive mechanisms underlying belief updating in humans can be described well within a Bayesian framework. PMID:26473170

  12. Extending the inverse scattering series free-surface-multiple-elimination algorithm by accommodating the source property on data with interfering or proximal seismic events

    Science.gov (United States)

    Zhao, Lei; Yang, Jinlong; Weglein, Arthur B.

    2017-12-01

    The inverse scattering series free-surface-multiple-elimination (FSME) algorithm is modified and extended to accommodate the source property-source radiation pattern. That accommodation can provide additional value for the fidelity of the free-surface multiple predictions. The new extended FSME algorithm retains all the merits of the original algorithm, i.e., fully data-driven and with a requirement of no subsurface information. It is tested on a one-dimensional acoustic model with proximal and interfering seismic events, such as interfering primaries and multiples. The results indicate the new extended FSME algorithm can predict more accurate free-surface multiples than methods without the accommodation of the source property if the source has a radiation pattern. This increased effectiveness in prediction contributes to removing free-surface multiples without damaging primaries. It is important in such cases to increase predictive effectiveness because other prediction methods, such as the surface-related-multiple-elimination algorithm, has difficulties and problems in prediction accuracy, and those issues affect efforts to remove multiples through adaptive subtraction. Therefore accommodation of the source property can not only improve the effectiveness of the FSME algorithm, but also extend the method beyond the current algorithm (e.g. improving the internal multiple attenuation algorithm).

  13. [Single event multilevel surgery to improve gait in diplegic cerebral palsy - a prospective controlled trial].

    Science.gov (United States)

    Zwick, E B; Saraph, V; Strobl, W; Steinwender, G

    2001-01-01

    To evaluate prospectively the outcome of gait-improvement surgery in children with spastic diplegia. Three-dimensional gait analysis was performed in twenty children with spastic diplegia. Ten children underwent single event multilevel surgery for gait improvement. Indications for individual procedures followed a fixed set of selection criteria. The other ten children continued with their physiotherapy programme and served as a control group. A second gait analysis was performed in all children after 1.5 years. Time-distance parameters and kinematics of the pelvis, hip, knee and ankle joints in the sagittal plane served as main outcome measures The patients walked faster with an increased stride length after surgery in comparison to the conservatively treated controls. The average pelvic tilt increased slightly and the range of motion of the knee joint increased considerably after multilevel surgery. The motion at the ankle remained unchanged over the study period in both the groups. An improved knee extension during the stance phase of gait served to improve stance limb stability and facilitated an unhindered swing phase of the opposite limb. This prospective trial showed favourable changes in gait function after multilevel surgery in spastic diplegic children.

  14. Monitoring single event upsets in SRAM-based FPGAs at the SuperKEKB interaction point

    Science.gov (United States)

    Giordano, R.; Tortone, G.; Perrella, S.; Izzo, V.; Aloisio, A.

    2017-07-01

    In February 2016, the SuperKEKB positron-electron high-luminosity collider of the KEK laboratory (Tsukuba, Japan) started being commissioned. A dedicated commissioning detector, named BEAST2, has been used to characterize beam backgrounds before the Belle2 detector was rolled into the beams and to provide tuning parameters for Monte Carlo simulations. BEAST2 consists of a fiberglass support structure and several sub-detectors mounted onto it, including time projection chambers (TPCs) and He-3 tubes. In this work, we present direct measurements of radiation-induced single event upsets in a SRAM-based FPGA device installed in BEAST2 at a distance of ~ 1 m from the beam interaction point. Our goal was to provide experimental results of the expected radiation-induced configuration upset rate and power consumption variation at Belle2 and at other experiments operating in similar radiation environments. Beam currents for both electron and positron rings spanned a range between 50 and 500 mA, therefore providing data about the FPGA operation in different radiation conditions. Even if the machine has not been providing collisions yet, as the beams were not focused to the interaction point, our results show a rate of 0.15 upsets/day averaged over the whole commissioning time frame. We had neither evidence of total dose effects on the FPGA power consumption nor of permanent damage to the device.

  15. Position sensitive regions in a generic radiation sensor based on single event upsets in dynamic RAMs

    International Nuclear Information System (INIS)

    Darambara, D.G.; Spyrou, N.M.

    1997-01-01

    Modern integrated circuits are highly complex systems and, as such, are susceptible to occasional failures. Semiconductor memory devices, particularly dynamic random access memories (dRAMs), are subject to random, transient single event upsets (SEUs) created by energetic ionizing radiation. These radiation-induced soft failures in the stored data of silicon based memory chips provide the foundation for a new, highly efficient, low cost generic radiation sensor. The susceptibility and the detection efficiency of a given dRAM device to SEUs is a complicated function of the circuit design and geometry, the operating conditions and the physics of the charge collection mechanisms involved. Typically, soft error rates measure the cumulative response of all sensitive regions of the memory by broad area chip exposure in ionizing radiation environments. However, this study shows that many regions of a dynamic memory are competing charge collection centres having different upset thresholds. The contribution to soft fails from discrete regions or individual circuit elements of the memory device is unambiguously separated. Hence the use of the dRAM as a position sensitive radiation detector, with high spatial resolution, is assessed and demonstrated. (orig.)

  16. Line-edge roughness induced single event transient variation in SOI FinFETs

    International Nuclear Information System (INIS)

    Wu Weikang; An Xia; Jiang Xiaobo; Chen Yehua; Liu Jingjing; Zhang Xing; Huang Ru

    2015-01-01

    The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

  17. Single-trial event-related potential extraction through one-unit ICA-with-reference

    Science.gov (United States)

    Lih Lee, Wee; Tan, Tele; Falkmer, Torbjörn; Leung, Yee Hong

    2016-12-01

    Objective. In recent years, ICA has been one of the more popular methods for extracting event-related potential (ERP) at the single-trial level. It is a blind source separation technique that allows the extraction of an ERP without making strong assumptions on the temporal and spatial characteristics of an ERP. However, the problem with traditional ICA is that the extraction is not direct and is time-consuming due to the need for source selection processing. In this paper, the application of an one-unit ICA-with-Reference (ICA-R), a constrained ICA method, is proposed. Approach. In cases where the time-region of the desired ERP is known a priori, this time information is utilized to generate a reference signal, which is then used for guiding the one-unit ICA-R to extract the source signal of the desired ERP directly. Main results. Our results showed that, as compared to traditional ICA, ICA-R is a more effective method for analysing ERP because it avoids manual source selection and it requires less computation thus resulting in faster ERP extraction. Significance. In addition to that, since the method is automated, it reduces the risks of any subjective bias in the ERP analysis. It is also a potential tool for extracting the ERP in online application.

  18. The application of particle filters in single trial event-related potential estimation

    International Nuclear Information System (INIS)

    Mohseni, Hamid R; Nazarpour, Kianoush; Sanei, Saeid; Wilding, Edward L

    2009-01-01

    In this paper, an approach for the estimation of single trial event-related potentials (ST-ERPs) using particle filters (PFs) is presented. The method is based on recursive Bayesian mean square estimation of ERP wavelet coefficients using their previous estimates as prior information. To enable a performance evaluation of the approach in the Gaussian and non-Gaussian distributed noise conditions, we added Gaussian white noise (GWN) and real electroencephalogram (EEG) signals recorded during rest to the simulated ERPs. The results were compared to that of the Kalman filtering (KF) approach demonstrating the robustness of the PF over the KF to the added GWN noise. The proposed method also outperforms the KF when the assumption about the Gaussianity of the noise is violated. We also applied this technique to real EEG potentials recorded in an odd-ball paradigm and investigated the correlation between the amplitude and the latency of the estimated ERP components. Unlike the KF method, for the PF there was a statistically significant negative correlation between amplitude and latency of the estimated ERPs, matching previous neurophysiological findings

  19. Low energy proton induced single event upset in 65 nm DDR and QDR commercial SRAMs

    Science.gov (United States)

    Ye, B.; Liu, J.; Wang, T. S.; Liu, T. Q.; Maaz, K.; Luo, J.; Wang, B.; Yin, Y. N.; Ji, Q. G.; Sun, Y. M.; Hou, M. D.

    2017-09-01

    The single event upset (SEU) response of 65 nm commercial double data rate static random access memory (SRAM) and quad data rate SRAM was investigated by using proton beams with energies in the range of 0.15 MeV to 8.0 MeV. Experimental results show that a significant number of SEU occurrences can be triggered when the energy of incident proton is below 1 MeV. For the low energy protons, the SEU cross section measured in these SRAMs was found to increase with increasing proton energy, attaining a peak value, and then decreases as the proton energy was further increased. While in case of quad data rate SRAMs, it seems that they are more sensitive to SEU occurrences as compared with double data rate SRAMs. The bias voltage and data pattern dependence on SEU cross section induced by the low energy protons were also investigated in this work. In addition, the over-layer thickness of the SRAMs and the impact of degrader use in proton induced SEU test were also analyzed in detail. Monte Carlo simulations results indicate that the use of degrader in case of low energy proton induced SEU test results in a significant reduction of the SEU cross section.

  20. Single-event burnout hardening of planar power MOSFET with partially widened trench source

    Science.gov (United States)

    Lu, Jiang; Liu, Hainan; Cai, Xiaowu; Luo, Jiajun; Li, Bo; Li, Binhong; Wang, Lixin; Han, Zhengsheng

    2018-03-01

    We present a single-event burnout (SEB) hardened planar power MOSFET with partially widened trench sources by three-dimensional (3D) numerical simulation. The advantage of the proposed structure is that the work of the parasitic bipolar transistor inherited in the power MOSFET is suppressed effectively due to the elimination of the most sensitive region (P-well region below the N+ source). The simulation result shows that the proposed structure can enhance the SEB survivability significantly. The critical value of linear energy transfer (LET), which indicates the maximum deposited energy on the device without SEB behavior, increases from 0.06 to 0.7 pC/μm. The SEB threshold voltage increases to 120 V, which is 80% of the rated breakdown voltage. Meanwhile, the main parameter characteristics of the proposed structure remain similar with those of the conventional planar structure. Therefore, this structure offers a potential optimization path to planar power MOSFET with high SEB survivability for space and atmospheric applications. Project supported by the National Natural Science Foundation of China (Nos. 61404161, 61404068, 61404169).

  1. 3D Thermal and Mechanical Analysis of a Single Event Burnout

    Science.gov (United States)

    Peretti, Gabriela; Demarco, Gustavo; Romero, Eduardo; Tais, Carlos

    2015-08-01

    This paper presents a study related to thermal and mechanical behavior of power DMOS transistors during a Single Event Burnout (SEB) process. We use a cylindrical heat generation region for emulating the thermal and mechanical phenomena related to the SEB. In this way, it is avoided the complexity of the mathematical treatment of the ion-device interaction. This work considers locating the heat generation region in positions that are more realistic than the ones used in previous work. For performing the study, we formulate and validate a new 3D model for the transistor that maintains the computational cost at reasonable level. The resulting mathematical models are solved by means of the Finite Element Method. The simulations results show that the failure dynamics is dominated by the mechanical stress in the metal layer. Additionally, the time to failure depends on the heat source position, for a given power and dimension of the generation region. The results suggest that 3D modeling should be considered for a detailed study of thermal and mechanical effects induced by SEBs.

  2. Calibration of a neutron detector based on single event upset of SRAM memories

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, C., E-mail: carles.domingo@uab.ca [Departament de Fisica, Univ. Autonoma de Barcelona, E-08193 Bellaterra (Spain); Gomez, F. [Dpto. de Particulas, Univ. de Santiago, 15782 Santiago de Compostela (Spain); Sanchez-Doblado, F. [Dpto. de Fisiologia Medica y Biofisica, Univ. de Sevilla, 41009 Sevilla (Spain); Servicio de Radiofisica, Hospital Univ. Virgen Macarena, 41009 Sevilla (Spain); Hartmann, G.H. [DKFZ E0400, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Amgarou, K.; Garcia-Fuste, M.J. [Departament de Fisica, Univ. Autonoma de Barcelona, E-08193 Bellaterra (Spain); Romero, M.T. [Dpto. de Fisiologia Medica y Biofisica, Univ. de Sevilla, 41009 Sevilla (Spain); Boettger, R.; Nolte, R.; Wissmann, F.; Zimbal, A.; Schuhmacher, H. [PTB, Bundesallee 100, 38116 Braunschweig (Germany)

    2010-12-15

    One of the challenges of measuring neutron fluences around medical linacs is the fact that the scattered photon fluence is important and higher than the surrounding neutron leakage fluence. Additionally most electron accelerators are pulsed, with repetition rates of the order of hundreds of Hertz, while the pulse duration is in the microsecond range. For this reason, neutron fluence around RT linacs is usually measured through passive methods, with the inconvenience of their time consuming analysis. A new neutron detector, based on the relation between Single Event Upsets (SEU) in digital SRAM memories and the existing thermal neutron fluence, has been developed. This work reports the calibration results of prototypes of this detector, obtained from exposures to the Physikalisch-Technische Bundesanstalt in Braunschweig (PTB) moderated {sup 252}Cf source, to PTB quasi-monoenergetic neutron beams of 0.565 MeV, 1.2 MeV, 5 MeV, 8 MeV and 14.8 MeV, and to the GKSS thermal neutron beam.

  3. SRAM single event upset calculation and test using protons in the secondary beam in the BEPC

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuanming; Guo Hongxia; Zhang Fengqi; Zhang Keying; Chen Wei; Luo Yinhong; Guo Xiaoqiang, E-mail: wangym2007@gmail.com [Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2011-09-15

    The protons in the secondary beam in the Beijing Electron Positron Collider (BEPC) are first analyzed and a large proportion at the energy of 50-100 MeV supply a source gap of high energy protons. In this study, the proton energy spectrum of the secondary beam was obtained and a model for calculating the proton single event upset (SEU) cross section of a static random access memory (SRAM) cell has been presented in the BEPC secondary beam proton radiation environment. The proton SEU cross section for different characteristic dimensions has been calculated. The test of SRAM SEU cross sections has been designed, and a good linear relation between SEUs in SRAM and the fluence was found, which is evidence that an SEU has taken place in the SRAM. The SEU cross sections were measured in SRAM with different dimensions. The test result shows that the SEU cross section per bit will decrease with the decrease of the characteristic dimensions of the device, while the total SEU cross section still increases upon the increase of device capacity. The test data accords with the calculation results, so the high-energy proton SEU test on the proton beam in the BEPC secondary beam could be conducted. (semiconductor physics)

  4. Impact of temperature on single event upset measurement by heavy ions in SRAM devices

    International Nuclear Information System (INIS)

    Liu Tianqi; Geng Chao; Zhang Zhangang; Gu Song; Tong Teng; Xi Kai; Hou Mingdong; Liu Jie; Zhao Fazhan; Liu Gang; Han Zhengsheng

    2014-01-01

    The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12 C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209 Bi and 12 C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12 C ions but keep constant for 209 Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

  5. Radiation induced Single Event Effects in the ATLAS MDT-ASD front-end chip

    CERN Document Server

    Posch, C

    2002-01-01

    Single Event Effect (SEE) tests of the MDT-ASD, the ATLAS MDT front-end chip have been performed at the Harvard Cyclotron Lab. The MDT-ASD is an 8-channel drift tube read-out ASIC fabricated in a commercial 0.5um CMOS process (AMOS14TB). The chip contains a 53 bit register which holds the setup information and an associated shift register of the same length plus some additional control logic. 10 test devices were exposed to a 160 MeV proton beam with a fluence of 1.05E9 p.cm-2.s-1 up to >4.4E p.cm-2 per device. After a total fluence of 4.46E13 p.cm-2, 7 soft SEEs (non-permanent bit flips in the registers) and 0 hard/destructive SEE (e.g. latch-ups, SEL) had occurred. The simulated fluence for 10 years of LHC operation at nominal luminosity for worst case location MDT components is 2.67E11 h.cm-2. The rate of SEUs in the ASD setup register for all of ATLAS, derived from these numbers, is 2.4 per day. It is foreseen to update the active registers of the on-detector electronics at regular intervals. Depending on...

  6. Seismic Catalogue and Seismic Network in Haiti

    Science.gov (United States)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.

    2013-05-01

    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  7. Wavelet based automated postural event detection and activity classification with single imu - biomed 2013.

    Science.gov (United States)

    Lockhart, Thurmon E; Soangra, Rahul; Zhang, Jian; Wu, Xuefan

    2013-01-01

    and classification algorithm using denoised signals from single wireless IMU placed at sternum. The algorithm was further validated and verified with motion capture system in laboratory environment. Wavelet denoising highlighted postural events and transition durations that further provided clinical information on postural control and motor coordination. The presented method can be applied in real life ambulatory monitoring approaches for assessing condition of elderly.

  8. Single-Event Latchup Testing of the Micrel MIC4424 Dual Power MOSFET Driver

    Science.gov (United States)

    Pellish, J. A.; Boutte, A.; Kim, H.; Phan, A.; Topper, A.

    2016-01-01

    We conducted 47 exposures of four different MIC4424 devices and did not observe any SEL or high-current events. This included worst-case conditions with a LET of 81 MeV-sq cm/mg, applied voltage of 18.5 V, a case temperature greater than 120 C, and a final fluence of 1x10(exp 7)/sq cm. We also monitored both the outputs for the presence of SETs. While the period of the 1 MHz square wave was slightly altered in some cases, no pulses were added or deleted. 1. Purpose: The purpose of this testing is to characterize the BiCMOS/DMOS Micrel MIC4424 dual, non-inverting MOSFET driver for single-event latchup (SEL) susceptibility. These data will be used for flight lot evaluation purposes. 2. Devices Tested: The MIC4423/4424/4425 family are highly reliable BiCMOS/DMOS buffer/driver MOSFET drivers. They are higher output current versions of the MIC4426/4427/4428. They can survive up to 5V of noise spiking, of either polarity, on the ground pin. They can accept, without either damage or logic upset, up to half an amp of reverse current (either polarity) forced back into their outputs. Primarily intended for driving power MOSFETs, the MIC4423/4424/4425 drivers are suitable for driving other loads (capacitive, resistive, or inductive) which require low-impedance, high peak currents, and fast switching times. Heavily loaded clock lines, coaxial cables, or piezoelectric transducers are some examples. The only known limitation on loading is that total power dissipated in the driver must be kept within the maximum power dissipation limits of the package. Five (5) parts were provided for SEL testing. We prepared four parts for irradiation and reserved one piece as an un-irradiated control. More information about the devices can be found in Table 1. The parts were prepared for testing by removing the lid from the CDIP package to expose the target die. The parts were then soldered to small copper circuit adapter boards for easy handling. These parts are fabricated in a bulk Bi

  9. Increased Cardiovascular Events and Subclinical Atherosclerosis in Rheumatoid Arthritis Patients: 1 Year Prospective Single Centre Study.

    Directory of Open Access Journals (Sweden)

    Piero Ruscitti

    Full Text Available Several studies showed the close relationship between Rheumatoid Arthritis (RA and cerebro-cardiovascular events (CVEs and subclinical atherosclerosis. In this study, we investigated the occurrence of CVEs and subclinical atherosclerosis during the course of RA and we evaluated the possible role of both traditional cardiovascular (CV and disease related risk factors to predict the occurrence of new CVEs and the onset of subclinical atherosclerosis.We designed a single centre, bias-adjusted, prospective, observational study to investigate, in a homogeneous subset of RA patients, the occurrence of new onset of CVEs and subclinical atherosclerosis. Statistical analyses were performed to evaluate the role of traditional CV and disease-related risk factors to predict the occurrence of new CVEs and subclinical atherosclerosis.We enrolled 347 RA patients prospectively followed for 12 months. An increased percentage of patients experienced CVEs, developed subclinical atherosclerosis and was affected by systemic arterial hypertension (SAH, type 2 diabetes mellitus and metabolic syndrome (MS, at the end of follow up. Our analysis showed that the insurgence of both SAH and MS, during the follow up, the older age, the CVE familiarity and the lack of clinical response, were associated with a significantly increased risk to experience CVEs and to develop subclinical atherosclerosis.Our study quantifies the increased expected risk for CVEs in a cohort of RA patients prospectively followed for 1 year. The occurrence of both new CVEs and subclinical atherosclerosis in RA patients may be explained by inflammatory burden as well as traditional CV risk factors.

  10. Mitigation of Temperature Induced Single Event Crosstalk Noise by Applying Adaptive Forward Body Bias

    Science.gov (United States)

    Bhowmik, Pankaj

    Soft Errors due to Single Event (SE) Transients is one of the important reliability issues, which is becoming very prominent in advanced technology and in space applications. Increasing coupling effects among interconnects, on the other hand, can cause SE Transients to contaminate electronically unrelated circuit paths, which in turn can increase circuit sensitivity to radiation. Coupling capacitance increases due to reducing distances between interconnect lines making crosstalk noise more important. On the other hand, chips now experience higher temperatures due to environmental factors and high performance of chips. High-performance VLSI circuits consume more power and hence experience higher temperature due to high utilization factor. The increased temperature affects both interconnect resistance and driving strength of interconnect buffers. This work shows that thermal effects increase the amount of crosstalk noise observed on the victim line at nominal supply voltages. With thermally induced crosstalk contribution, total crosstalk noise may exceed the noise margin of the subsequent gate causing a wrong value to be propagated. The crosstalk prevention measures taken such as victim driver sizing may not be sufficient if thermal effects are not properly considered. This work aims to provide a mitigation method for thermally induced crosstalk noise using adaptive forward body bias. At high temperature, drain current reduces, and adaptive body biasing makes the CMOS recover the lost the drain current. A temperature sensor is proposed here to generate a necessary voltage at the CMOS body. A good temperature sensitivity is achieved with the tiny sensors that keep constant driving strength. Interconnect is modeled in using 10-pi modeling and 45nm technology was use for this simulation. Our proposed method mitigates 90% of temperature induced crosstalk contribution.

  11. Development of Single-Event Upset hardened programmable logic devices in deep submicron CMOS

    International Nuclear Information System (INIS)

    Bonacini, S.

    2007-11-01

    The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust (Single Event Upset) programmable components for application in high energy physics experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 μm CMOS technology. The FPGA under development is a 32*32 logic block array, equivalent to ∼ 25 k gates, in 0.13 μm CMOS. The irradiation test results obtained in the CMOS 0.25 μm technology demonstrate good robustness of the circuit up to an LET (Linear Energy Transfer) of 79.6 cm 2 *MeV/mg, which make it suitable for the target environment. The CMOS 0.13 μm circuit has showed robustness to an LET of 37.4 cm 2 *MeV/mg in the static test mode and has increased sensitivity in the dynamic test mode. This work focused also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design

  12. Rockfall induced seismic signals: case study in Montserrat, Catalonia

    Directory of Open Access Journals (Sweden)

    I. Vilajosana

    2008-08-01

    Full Text Available After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts.

    On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10−4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 – A rockfall event generates seismic signals with specific characteristics in the time domain; 2 – the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact. This feature could

  13. Single-Event Transient Testing of the Crane Aerospace and Electronics SMHF2812D Dual DC-DC Converter

    Science.gov (United States)

    Casey, Megan

    2015-01-01

    The purpose of this testing was to characterize the Crane Aerospace & Electronics (Crane) Interpoint SMHF2812D for single-event transient (SET) susceptibility. These data shall be used for flight lot evaluation, as well as qualification by similarity of the SMHF family of converters, all of which use the same active components.

  14. Recent lifeline seismic risk studies

    Energy Technology Data Exchange (ETDEWEB)

    Kiremidjian, A.S.

    1990-01-01

    The objective of this book is to present some recent earthquake hazard and vulnerability analysis models for lifeline systems. The approach considered is different from seismic risk analysis of conventional structures in that lifelines are spatially distributed with components exposed to varying hazard levels. Losses to lifeline systems can result from direct damage to components that are affected by a single event or they can be due to down time and unavailability of the product they supply. The emphasis in the papers is on the evaluation of direct losses from failures of various types of systems. Methods for estimating direct losses and treatment of uncertainties are described in two of the papers. The approach considered is general and can be applied to most lifeline systems. Example analyses include water and transportation systems. Several of the papers summarize developments made under the Seismic Risk Assessment Study for Water and Sewage Systems conducted by the Seismic Risk Committee of the Technical Council for Lifeline Earthquake Engineering of ASCE.

  15. Definition of Capabilities Needed for a Single Event Effects Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Riemer, Bernie [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Gallmeier, Franz X. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

    2014-12-01

    The Federal Aviation Administration (FAA) is contemplating new regulations mandating testing of the vulnerability of flight-critical avionics to single event effects (SEE). A limited number of high-energy neutron test facilities currently serve the SEE industrial and institutional research community. The FAA recognizes that existing facilities have insufficient test capacity to meet new demand from such mandates; it desires more flexible irradiation capabilities to test complete, large systems and would like capabilities to address greater concerns for thermal neutrons. For this reason, the FAA funded this study by Spallation Neutron Source (SNS) staff with the ultimate aim of developing options for SEE test facilities using high-energy neutrons at the SNS complex. After an investigation of current SEE test practices and assessment of future testing requirements, three concepts were identified covering a range of test functionality, neutron flux levels, and fidelity to the atmospheric neutron spectrum. The costs and times required to complete each facility were also estimated. SEE testing is generally performed by accelerating the event rate to a point where the effects are still dominated by single events and double event causes of failures are negligible. In practice, acceleration factors of as high as 106 are applicable for component testing, whereas for systems testing acceleration factors of 104 seem to be the upper limit. It is strongly desirable that the irradiation facility be tunable over a large range of high-energy neutron fluxes of 102 - 104 n/cm²/s for systems testing and from 104 - 107 n/cm²/s for components testing. The most capable, most flexible, and highest-test-capacity option is a new stand-alone target station named the High-Energy neutron Test Station (HETS). It is also the most expensive option, with a cost to complete of approximately $100 million. Dual test enclosures would

  16. Searches for new physics in single-photon events and a search for charginos at the DELPHI experiment

    CERN Document Server

    Ask, S M

    2004-01-01

    A search for new physics using events with a single photon and missing energy has been made at the DELPHI experiment together with a search for charginos. The results were based on data collected up to and including the final year of 2000. An integrated luminosity of 650 pb−1 was used in the single photon analysis and 450 pb−1 in the chargino search. Center-of-mass energies up to 209 GeV were explored. Searches have been made for supersymmetry as well as for extra dimensions and non standard neutrino interactions. Since no signs of a signal have been observed in any of the searches the results have been used to set exclusion limits and to constrain the theoretical parameter spaces. The search results using single and acoplanar photon events from the four LEP experiments have also been combined within the searches for supersymmetry and extra dimensions.

  17. Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

    Science.gov (United States)

    Pellish, Jonathan A.; Marshall, Paul W.; Rodbell, Kenneth P.; Gordon, Michael S.; LaBel, Kenneth A.; Schwank, James R.; Dodds, Nathaniel A.; Castaneda, Carlos M.; Berg, Melanie D.; Kim, Hak S.; hide

    2014-01-01

    We report low-energy proton and low-energy alpha particle single-event effects (SEE) data on a 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) latches and static random access memory (SRAM) that demonstrates the criticality of using low-energy protons for SEE testing of highly-scaled technologies. Low-energy protons produced a significantly higher fraction of multi-bit upsets relative to single-bit upsets when compared to similar alpha particle data. This difference highlights the importance of performing hardness assurance testing with protons that include energy distribution components below 2 megaelectron-volt. The importance of low-energy protons to system-level single-event performance is based on the technology under investigation as well as the target radiation environment.

  18. Seismic Methods

    Science.gov (United States)

    Seismic methods are the most commonly conducted geophysical surveys for engineering investigations. Seismic refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.

  19. Single-Event Gate Rupture in Power MOSFETs: A New Radiation Hardness Assurance Approach

    Science.gov (United States)

    Lauenstein, Jean-Marie

    2011-01-01

    Almost every space mission uses vertical power metal-semiconductor-oxide field-effect transistors (MOSFETs) in its power-supply circuitry. These devices can fail catastrophically due to single-event gate rupture (SEGR) when exposed to energetic heavy ions. To reduce SEGR failure risk, the off-state operating voltages of the devices are derated based upon radiation tests at heavy-ion accelerator facilities. Testing is very expensive. Even so, data from these tests provide only a limited guide to on-orbit performance. In this work, a device simulation-based method is developed to measure the response to strikes from heavy ions unavailable at accelerator facilities but posing potential risk on orbit. This work is the first to show that the present derating factor, which was established from non-radiation reliability concerns, is appropriate to reduce on-orbit SEGR failure risk when applied to data acquired from ions with appropriate penetration range. A second important outcome of this study is the demonstration of the capability and usefulness of this simulation technique for augmenting SEGR data from accelerator beam facilities. The mechanisms of SEGR are two-fold: the gate oxide is weakened by the passage of the ion through it, and the charge ionized along the ion track in the silicon transiently increases the oxide electric field. Most hardness assurance methodologies consider the latter mechanism only. This work demonstrates through experiment and simulation that the gate oxide response should not be neglected. In addition, the premise that the temporary weakening of the oxide due to the ion interaction with it, as opposed to due to the transient oxide field generated from within the silicon, is validated. Based upon these findings, a new approach to radiation hardness assurance for SEGR in power MOSFETs is defined to reduce SEGR risk in space flight projects. Finally, the potential impact of accumulated dose over the course of a space mission on SEGR

  20. FinFET memory cell improvements for higher immunity against single event upsets

    Science.gov (United States)

    Sajit, Ahmed Sattar

    The 21st century is witnessing a tremendous demand for transistors. Life amenities have incorporated the transistor in every aspect of daily life, ranging from toys to rocket science. Day by day, scaling down the transistor is becoming an imperious necessity. However, it is not a straightforward process; instead, it faces overwhelming challenges. Due to these scaling changes, new technologies, such as FinFETs for example, have emerged as alternatives to the conventional bulk-CMOS technology. FinFET has more control over the channel, therefore, leakage current is reduced. FinFET could bridge the gap between silicon devices and non-silicon devices. The semiconductor industry is now incorporating FinFETs in systems and subsystems. For example, Intel has been using them in their newest processors, delivering potential saving powers and increased speeds to memory circuits. Memory sub-systems are considered a vital component in the digital era. In memory, few rows are read or written at a time, while the most rows are static; hence, reducing leakage current increases the performance. However, as a transistor shrinks, it becomes more vulnerable to the effects from radioactive particle strikes. If a particle hits a node in a memory cell, the content might flip; consequently, leading to corrupting stored data. Critical fields, such as medical and aerospace, where there are no second chances and cannot even afford to operate at 99.99% accuracy, has induced me to find a rigid circuit in a radiated working environment. This research focuses on a wide spectrum of memories such as 6T SRAM, 8T SRAM, and DICE memory cells using FinFET technology and finding the best platform in terms of Read and Write delay, susceptibility level of SNM, RSNM, leakage current, energy consumption, and Single Event Upsets (SEUs). This research has shown that the SEU tolerance that 6T and 8T FinFET SRAMs provide may not be acceptable in medical and aerospace applications where there is a very high

  1. Iceberg calving as a primary source of regional‐scale glacier‐generated seismicity in the St. Elias Mountains, Alaska

    Science.gov (United States)

    O'Neel, Shad; Larsen, Christopher F.; Rupert, Natalia; Hansen, Roger

    2010-01-01

    Since the installation of the Alaska Regional Seismic Network in the 1970s, data analysts have noted nontectonic seismic events thought to be related to glacier dynamics. While loose associations with the glaciers of the St. Elias Mountains have been made, no detailed study of the source locations has been undertaken. We performed a two-step investigation surrounding these events, beginning with manual locations that guided an automated detection and event sifting routine. Results from the manual investigation highlight characteristics of the seismic waveforms including single-peaked (narrowband) spectra, emergent onsets, lack of distinct phase arrivals, and a predominant cluster of locations near the calving termini of several neighboring tidewater glaciers. Through these locations, comparison with previous work, analyses of waveform characteristics, frequency-magnitude statistics and temporal patterns in seismicity, we suggest calving as a source for the seismicity. Statistical properties and time series analysis of the event catalog suggest a scale-invariant process that has no single or simple forcing. These results support the idea that calving is often a response to short-lived or localized stress perturbations. Our results demonstrate the utility of passive seismic instrumentation to monitor relative changes in the rate and magnitude of iceberg calving at tidewater glaciers that may be volatile or susceptible to ensuing rapid retreat, especially when existing seismic infrastructure can be used.

  2. A single hot event stimulates adult performance but reduces egg survival in the oriental fruit moth, Grapholitha molesta.

    Science.gov (United States)

    Liang, Li-Na; Zhang, Wei; Ma, Gang; Hoffmann, Ary A; Ma, Chun-Sen

    2014-01-01

    Climate warming is expected to increase the exposure of insects to hot events (involving a few hours at extreme high temperatures). These events are unlikely to cause widespread mortality but may modify population dynamics via impacting life history traits such as adult fecundity and egg hatching. These effects and their potential impact on population predictions are still largely unknown. In this study, we simulated a single hot event (maximum of 38°C lasting for 4 h) of a magnitude increasingly found under field conditions and examined its effect in the oriental fruit moth, Grapholitha molesta. This hot event had no impact on the survival of G. molesta adults, copulation periods or male longevity. However, the event increased female lifespan and the length of the oviposition period, leading to a potential increase in lifetime fecundity and suggesting hormesis. In contrast, exposure of males to this event markedly reduced the net reproductive value. Male heat treatment delayed the onset of oviposition in the females they mated with, as well as causing a decrease in the duration of oviposition period and lifetime fecundity. Both male and female stress also reduced egg hatch. Our findings of hormetic effects on female performance but concurrent detrimental effects on egg hatch suggest that hot events have unpredictable consequences on the population dynamics of this pest species with implications for likely effects associated with climate warming.

  3. A single hot event stimulates adult performance but reduces egg survival in the oriental fruit moth, Grapholitha molesta.

    Directory of Open Access Journals (Sweden)

    Li-Na Liang

    Full Text Available Climate warming is expected to increase the exposure of insects to hot events (involving a few hours at extreme high temperatures. These events are unlikely to cause widespread mortality but may modify population dynamics via impacting life history traits such as adult fecundity and egg hatching. These effects and their potential impact on population predictions are still largely unknown. In this study, we simulated a single hot event (maximum of 38°C lasting for 4 h of a magnitude increasingly found under field conditions and examined its effect in the oriental fruit moth, Grapholitha molesta. This hot event had no impact on the survival of G. molesta adults, copulation periods or male longevity. However, the event increased female lifespan and the length of the oviposition period, leading to a potential increase in lifetime fecundity and suggesting hormesis. In contrast, exposure of males to this event markedly reduced the net reproductive value. Male heat treatment delayed the onset of oviposition in the females they mated with, as well as causing a decrease in the duration of oviposition period and lifetime fecundity. Both male and female stress also reduced egg hatch. Our findings of hormetic effects on female performance but concurrent detrimental effects on egg hatch suggest that hot events have unpredictable consequences on the population dynamics of this pest species with implications for likely effects associated with climate warming.

  4. A Single Hot Event Stimulates Adult Performance but Reduces Egg Survival in the Oriental Fruit Moth, Grapholitha molesta

    Science.gov (United States)

    Ma, Gang; Hoffmann, Ary A.; Ma, Chun-Sen

    2014-01-01

    Climate warming is expected to increase the exposure of insects to hot events (involving a few hours at extreme high temperatures). These events are unlikely to cause widespread mortality but may modify population dynamics via impacting life history traits such as adult fecundity and egg hatching. These effects and their potential impact on population predictions are still largely unknown. In this study, we simulated a single hot event (maximum of 38°C lasting for 4 h) of a magnitude increasingly found under field conditions and examined its effect in the oriental fruit moth, Grapholitha molesta. This hot event had no impact on the survival of G. molesta adults, copulation periods or male longevity. However, the event increased female lifespan and the length of the oviposition period, leading to a potential increase in lifetime fecundity and suggesting hormesis. In contrast, exposure of males to this event markedly reduced the net reproductive value. Male heat treatment delayed the onset of oviposition in the females they mated with, as well as causing a decrease in the duration of oviposition period and lifetime fecundity. Both male and female stress also reduced egg hatch. Our findings of hormetic effects on female performance but concurrent detrimental effects on egg hatch suggest that hot events have unpredictable consequences on the population dynamics of this pest species with implications for likely effects associated with climate warming. PMID:25551751

  5. A single laboratory setup for investigating the anisotropy of both seismic and electrical properties in core samples

    Science.gov (United States)

    David, Christian; Robion, Philippe; Louis, Laurent

    2017-09-01

    A fully automated versatile device is presented for analysing the anisotropy of both seismic and electrical properties on cylindrical rock samples. Initially devoted to the study of P-wave velocity anisotropy (APV), the system has been upgraded to allow the measurement of electrical conductivity anisotropy (AEC) as well. The improved setup allows for the estimation of the APV and AEC, from measurements across multiple diameters with an angular spacing selected by the operator. In order to determine the APV simplified tensor and the true AEC tensor, at least three mutually orthogonal samples are required. Switching from velocity to electrical measurements only requires replacing the pair of ultrasonic transducers by a pair of electrodes. Whereas the procedure is quite straightforward for the P-wave velocity analysis, different calibration steps and approximations are required in the processing of the electrical data. As an example the methodology was applied to a set of two rocks, the Leopard and the Castlegate sandstones, for which the APV and AEC are compared in a unified scheme. Good agreement was found between the orientation of the symmetry axes for both properties, suggesting that in the studied rocks pore space anisotropy accounts for both velocity and electrical anisotropy. This methodology can also be incorporated into a core analysis workflow to obtain a first-hand assessment of the rock fabric orientation and anisotropy with respect to seismic and transport properties. The information thus obtained can be used as a screening step for sampling and stress testing as well as for direct core to log integration and cross-property correlations.

  6. Single-station seismic noise measures, microgravity, and 3D electrical tomographies to assess the sinkhole susceptibility: the "Il Piano" area (Elba Island - Italy) case study

    Science.gov (United States)

    Pazzi, Veronica; Di Filippo, Michele; Di Nezza, Maria; Carlà, Tommaso; Bardi, Federica; Marini, Federico; Fontanelli, Katia; Intrieri, Emanuele; Fanti, Riccardo

    2017-04-01

    Sudden subsurface collapse, cavities, and surface depressions, regardless of shape and origin, as well as doline are currently indicate by means of the term "sinkhole". This phenomenon can be classified according to a large variety of different schemes, depending on the dominant formation processes (soluble rocks karstic processes, acidic groundwater circulation, anthropogenic caves, bedrock poor geomechanical properties), and on the geological scenario behind the development of the phenomenon. Considering that generally sinkholes are densely clustered in "sinkhole prone areas", detection, forecasting, early warning, and effective monitoring are key aspects in sinkhole susceptibility assessment and risk mitigation. Nevertheless, techniques developed specifically for sinkhole detection, forecasting and monitoring are missing, probably because of a general lack of sinkhole risk awareness, and an intrinsic difficulties involved in detecting precursory sinkhole deformations before collapse. In this framework, integration of different indirect/non-invasive geophysical methods is the best practice approach. In this paper we present the results of an integrated geophysical survey at "Il Piano" (Elba Island - Italy), where at least nine sinkholes occurred between 2008 and 2014. 120 single-station seismic noise measures, 17 3D electrical tomographies (min area 140.3 m2, max area 10,188.9 m2; min electrode spacing 2 m, max electrode spacing 5 m), 964 measurement of microgravity spaced in a grid of 6 m to 8 m were carried out at the study area. The most likely origin for these sinkholes was considered related to sediment net erosion from the alluvium, caused by downward water circulation between aquifers. Therefore, the goals of the study were: i) obtaining a suitable geological and hydrogeological model of the area; ii) detecting possible cavities which could evolve in sinkholes, and finally iii) assess the sinkhole susceptibility of the area. Among the results of the

  7. Success in treating renal calculi with single-access, single-event percutaneous nephrolithotomy: is a routine "second look" necessary?

    Science.gov (United States)

    Davol, Patrick E; Wood, Craig; Fulmer, Brant

    2006-05-01

    Percutaneous nephrolithotomy (PCNL) is an effective procedure for the treatment of large renal calculi. An important consideration for patients undergoing PCNL is the management of any residual stone burden, which may include "second-look" nephroscopy. The utility of this practice is unproven, and we present our data on a series of patients in which second-look procedures were not performed. We retrospectively reviewed the records of 43 consecutive patients undergoing a total of 45 procedures by a single surgeon at a tertiary-care center. Patients were considered stone free if no calculi were evident by either plain film or noncontrast CT scan. Statistical analysis was used to look for correlations between radiographic stone clearance and various patient and stone characteristics. Of these procedures, 15% had immediate postoperative evidence of residual fragments. At a mean follow-up of 8 months, 32.5% had residual or recurrent stone. There were statistically significant correlations between both patient age and stone size and the risk of recurrent or residual stone. In our study, PCNL was effective for the single-stage treatment of large renal calculi. Aggressive stone clearance obviated the need for routine second-look nephroscopy. Factors leading to an increased risk of residual or recurrent calculi included the presence of a staghorn calculus and younger patient age. The excellent stone-free rates achieved suggest that routine second-look nephroscopy may not be necessary for the majority of patients undergoing PCNL.

  8. Time dependent seismic hazard

    Science.gov (United States)

    Polidoro, B.; Iervolino, I.; Chioccarelli, E.; Giorgio, M.

    2012-04-01

    Probabilistic seismic hazard is usually computed trough a homogeneous Poisson process that even though it is a time-independent process it is widely used for its very convenient properties. However, when a single fault is of concern and/or the time scale is different from that of the long term, time-dependent processes are required. In this paper, different time-dependent models are reviewed with working examples. In fact, the Paganica fault (in central Italy) has been considered to compute both the probability of occurrence of at least one event in the lifespan of the structure, as well as the seismic hazard expressed in terms of probability of exceedance of an intensity value in a given time frame causing the collapse of the structure. Several models, well known or novel application to engineering hazard have been considered, limitation and issues in their applications are also discussed. The Brownian Passage Time (BPT) model is based on a stochastic modification of the deterministic stick-slip oscillator model for characteristic earthquakes; i.e., based on the addition of random perturbations (a Gaussian white noise) to the deterministic load path predicted by elastic rebound theory. This model assumes that the load state is at some ground level immediately after an event, increases steadly over time, reaches a failure threshold and relaxes instantaneously back to the ground level. For this model also a variable threshold has been considered to take into account the uncertainty of the threshold value. For the slip-predictable model it is assumed that the stress accumulates at a constant rate starting from some initial stress level. Stress is assumed to accumulate for a random period of time until an earthquake occurs. The size of the earthquake is governed by the stress release and it is a function of the elapsed time since the last event. In the time-predictable model stress buildup occurs at a constant rate until the accumulated stress reaches a threshold

  9. Two-dimensional numerical simulation of the effect of single event burnout for n-channel VDMOSFET

    International Nuclear Information System (INIS)

    Guo Hongxia; Chen Yusheng; Wang Wei; Zhao Jinlong; Zhang Yimen; Zhou Hui

    2004-01-01

    2D MEDICI simulator is used to investigate the effect of Single Event Burnout (SEB) for n-channel power VDMOSFETs. The simulation results are consistent with experimental results which have been published. The simulation results are of great interest for a better understanding of the occurrence of events. The effects of the minority carrier lifetime in the base region, the base width and the emitter doping density on SEB susceptibility are verified. Some hardening solutions to SEB are provided. The work shows that the 2D simulator MEDICI is an useful tool for burnout prediction and for the evaluation of hardening solutions. (authors)

  10. A review of seismic risk applications

    International Nuclear Information System (INIS)

    Donovan, N.C.; Bornstein, A.E.

    1975-01-01

    Probabilistic procedures can be applied to evaluation of seismic risk in practical situations related to consulting engineering practice. Seismic risk results have been successfully used for correlation of a case with multiple events in highly seismic areas. (orig./RW) [de

  11. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1. Volume 5: Analysis of core damage frequency from seismic events during mid-loop operations

    Energy Technology Data Exchange (ETDEWEB)

    Budnitz, R.J. [Future Resources Associates, Inc., Berkeley, CA (United States); Davis, P.R. [PRD Consulting (United States); Ravindra, M.K.; Tong, W.H. [EQE International, Inc., Irvine, CA (United States)

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1) and the other at Sandia National Laboratories studying a boiling water reactor (Grand Gulf). Both the Brookhaven and Sandia projects have examined only accidents initiated by internal plant faults--so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling shutdown conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Surry Unit 1. All of the many systems modeling assumptions, component non-seismic failure rates, and human error rates that were used in the internal-initiator study at Surry have been adopted here, so that the results of the two studies can be as comparable as possible. Both the Brookhaven study and this study examine only two shutdown plant operating states (POSs) during refueling outages at Surry, called POS 6 and POS 10, which represent mid-loop operation before and after refueling, respectively. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POSs 6 and 10. The results of the analysis are that the core-damage frequency of earthquake-initiated accidents during refueling outages in POS 6 and POS 10 is found to be low in absolute terms, less than 10{sup {minus}6}/year.

  12. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1. Volume 5: Analysis of core damage frequency from seismic events during mid-loop operations

    International Nuclear Information System (INIS)

    Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1) and the other at Sandia National Laboratories studying a boiling water reactor (Grand Gulf). Both the Brookhaven and Sandia projects have examined only accidents initiated by internal plant faults--so-called ''internal initiators.'' This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling shutdown conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Surry Unit 1. All of the many systems modeling assumptions, component non-seismic failure rates, and human error rates that were used in the internal-initiator study at Surry have been adopted here, so that the results of the two studies can be as comparable as possible. Both the Brookhaven study and this study examine only two shutdown plant operating states (POSs) during refueling outages at Surry, called POS 6 and POS 10, which represent mid-loop operation before and after refueling, respectively. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POSs 6 and 10. The results of the analysis are that the core-damage frequency of earthquake-initiated accidents during refueling outages in POS 6 and POS 10 is found to be low in absolute terms, less than 10 -6 /year

  13. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    Energy Technology Data Exchange (ETDEWEB)

    Budnitz, R.J. [Future Resources Associates, Inc., Berkeley, CA (United States); Davis, P.R. [PRD Consulting (United States); Ravindra, M.K.; Tong, W.H. [EQE International, Inc., Irvine, CA (United States)

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven projects have examined only accidents initiated by internal plant faults---so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10{sup {minus}7}/year.

  14. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    International Nuclear Information System (INIS)

    Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven projects have examined only accidents initiated by internal plant faults---so-called ''internal initiators.'' This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10 -7 /year

  15. NASA Electronic Parts and Packaging (NEPP) Field Programmable Gate Array (FPGA) Single Event Effects (SEE) Test Guideline Update

    Science.gov (United States)

    Berg, Melanie D.; LaBel, Kenneth A.

    2018-01-01

    The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

  16. Temperature control system for the study of single event effects in integrated circuits using a cyclotron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Bakerenkov, A.S., E-mail: as_bakerenkov@list.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Belyakov, V.V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Kozyukov, A.E. [Joint-Stock Company Institute of Space Device Engineering (JSC ISDE), Moscow (Russian Federation); Pershenkov, V.S.; Solomatin, A.V.; Shurenkov, V.V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-02-11

    The temperature control system for the study of single event disruptions produced by hard ion impacts in integrated circuits is described. Heating and cooling of the irradiated device are achieved using thermoelectric modules (Peltier modules). The thermodynamic performance of the system is estimated. The technique for the numerical estimation of the main parameters of the temperature control system for cooling and heating is considered. The results of a test of the system in a vacuum cell of an accelerator are presented.

  17. Investigations on heavy ion induced Single-Event Transients (SETs) in highly-scaled FinFETs

    International Nuclear Information System (INIS)

    Gaillardin, M.; Raine, M.; Paillet, P.; Adell, P.C.; Girard, S.; Duhamel, O.; Andrieu, F.; Barraud, S.; Faynot, O.

    2015-01-01

    We investigate Single-Event Transients (SET) in different designs of multiple-gate devices made of FinFETs with various geometries. Heavy ion experimental results are explained by using a thorough charge collection analysis of fast transients measured on dedicated test structures. Multi-level simulations are performed to get new insights into the charge collection mechanisms in multiple-gate devices. Implications for multiple-gate device design hardening are finally discussed.

  18. Data from investigation on seismic Sea-waves events in the Eastern Mediterranean from the Birth of Christ to 500 A.D.

    Directory of Open Access Journals (Sweden)

    J. ANTONOPOULOS

    1980-06-01

    Full Text Available The Eastern Mediterranean has a long history of damaging seismic sea
    waves (Tsunamis but a great number of them which are locally generated are small. They have caused no serious damage to the coasts because their
    energy is confined by many islands of the Greek Archipelagos. However,
    some of them have been rather severe and destructive to property and
    human life.
    This paper is comprised of data from an investigation into the activity
    of seismic sea waves in the Eastern Mediterranean from the Birth of
    Christ to 500 A.D. It contains a great amount of information concerning
    earthquakes, volcanic eruptions and seismic sea waves.
    All the available information has been compiled from historical accounts,
    archives, press reports, magazines and related works.

  19. Topological events in single molecules of long genomic DNA confined in nanochannels

    Science.gov (United States)

    Reifenberger, Jeffrey; Dorfman, Kevin; Cao, Han

    2014-03-01

    ct- We present a rapid genome-wide analysis method based on new NanoChannel Array technology (IrysTM System) that confines and linearizes extremely long DNA molecules (100 to 1,000 kilobases) for direct image analysis at tens to hundred of gigabases per run. Genomic DNA is stained with YOYO and labeled specifically at the `GCTCTTC' sequence with fluorescent dyes allowing each molecule to be uniquely patterned and mapped to its corresponding reference. This high-throughput platform automates the imaging of such barcoded patterns on genomic DNA to identify wide spread structural variations in a genome. Here we describe a method to rule out possible topologically altered molecules in linear confinement by identifying possible topological events through a T-test looking for spikes in the fluorescence of the YOYO stained DNA backbone. These events are confirmed through aligning the marked individual molecules to a standard reference and measuring a distance differential between labels surrounding the suspected topological event compared to the reference. Such events could be flagged to distinguish from true structural variations.

  20. High-energy heavy ion testing of VLSI devices for single event ...

    Indian Academy of Sciences (India)

    Unknown

    board pattern of 55h (01010101) and AAh (10101010) in alternate locations during irradiation. Data stored in the memory is continuously read and verified with the refer- ence data pattern. In the event of any upset, the failure is recorded and the data is re-written again. This reading and writing process continues during the ...

  1. Helicity of the $W$ boson in single - lepton $t \\bar{t}$ events

    Energy Technology Data Exchange (ETDEWEB)

    Canelli, Maria Florencia [Rochester U.

    2003-08-01

    We have applied a general approach for extracting information from data to a study of top quarks produced in proton-antiproton (pp) collisions in the process pp ! tt. This reaction can be calculated in the Standard Model (SM), in which the top (or antitop) quarks decay into b quarks and W bosons: t ! W+ b, t ! W b. We examine the decays of the W boson in these events in order to establish how the spin of the W correlates with its momentum vector. This is dened by the helicity of the W boson (pro jection of its spin along its line of ight), which is also predicted by the SM. The analysis is based on a direct calculation of a probability for each event as a function of the helicity of the W bosons in top-antitop events in the lepton+jets nal state. These events correspond to one W decaying into a lepton and its neutrino, and the other W into a quark-antiquark pair, with the quarks from the W and the two b quarks evolving into jets of particles. The probability is calculated by convoluting the dierential cross section with the resolution and acceptance of the detector. This measurement uses top quarks collected by the D experiment in 125 events/pb of data in pp collisions at p s=1.8 TeV during Run I of the Fermilab TeVatron. Assuming the \\V{A" coupling of the SM decay, we obtain a longitudinal helicity fraction of F0=0.560.31(stat)0.07(syst) for the W, which is consistent with the prediction of the Standard Model of F0=0.70 for a top-quark mass of 175 GeV/c2 . The method employed in this analysis oers the possibility of increasing statistical precision by using both of the decays of W bosons in these events. Also Monte Carlo studies indicate that the approach provides an unbiased result in the limit of poor statistics. Although our measurement is severely limited by the small event sample of Run I, this powerful technique will provide far greater sensitivity to any departures from the SM in the data anticipated from Run II.

  2. Measurement of the associated production of a single top quark and a W boson in single-lepton events with the ATLAS detector

    International Nuclear Information System (INIS)

    Mergelmeyer, Sebastian

    2016-06-01

    The production of a single top quark in association with a W boson (Wt) is measured with the ATLAS detector using proton-proton collision events with one lepton, three jets and missing transverse energy at √(s)=8 TeV. Signal events are identified using an artificial neural network in an unconventional manner, addressing the large uncertainties due to the major background, which has an about 10 times larger cross section and a very similar signature compared with the Wt signal. State-of-the-art statistical methods are used to validate the modelling of the signal and the background, and to extract the cross section for Wt production. The cross section is found to be consistent with related measurements as well as the Standard Model prediction. In addition, a direct measurement of the CKM matrix element V tb is performed.

  3. Seismic Consequence Abstraction

    International Nuclear Information System (INIS)

    Gross, M.

    2004-01-01

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274])

  4. Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2004-10-25

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  5. The Influence of Age at Single-Event Multilevel Surgery on Outcome in Children with Cerebral Palsy Who Walk with Flexed Knee Gait

    Science.gov (United States)

    Svehlik, Martin; Steinwender, Gerhard; Kraus, Tanja; Saraph, Vinay; Lehmann, Thomas; Linhart, Wolfgang E.; Zwick, Ernst B.

    2011-01-01

    Aim: Information on the timing and long-term outcome of single-event multilevel surgery in children with bilateral spastic cerebral palsy (CP) walking with flexed knee gait is limited. Based on our clinical experience, we hypothesized that older children with bilateral spastic CP would benefit more from single-event multilevel surgery than younger…

  6. A microprocessor-based single board computer for high energy physics event pattern recognition

    International Nuclear Information System (INIS)

    Bernstein, H.; Gould, J.J.; Imossi, R.; Kopp, J.K.; Love, W.A.; Ozaki, S.; Platner, E.D.; Kramer, M.A.

    1981-01-01

    A single board MC 68000 based computer has been assembled and bench marked against the CDC 7600 running portions of the pattern recognition code used at the MPS. This computer has a floating coprocessor to achieve throughputs equivalent to several percent that of the 7600. A major part of this work was the construction of a FORTRAN compiler including assembler, linker and library. The intention of this work is to assemble a large number of these single board computers in a parallel FASTBUS environment to act as an on-line and off-line filter for the raw data from MPS II and ISABELLE experiments. (orig.)

  7. Microprocessor-based single board computer for high energy physics event pattern recognition

    International Nuclear Information System (INIS)

    Bernstein, H.; Gould, J.J.; Imossi, R.; Kopp, J.K.; Love, W.A.; Ozaki, S.; Platner, E.D.; Kramer, M.A.

    1981-01-01

    A single board MC 68000 based computer has been assembled and bench marked against the CDC 7600 running portions of the pattern recognition code used at the MPS. This computer has a floating coprocessor to achieve throughputs equivalent to several percent that of the 7600. A major part of this work was the construction of a FORTRAN compiler including assembler, linker and library. The intention of this work is to assemble a large number of these single board computers in a parallel FASTBUS environment to act as an on-line and off-line filter for the raw data from MPS II and ISABELLE experiments

  8. Autonomous Gait Event Detection with Portable Single-Camera Gait Kinematics Analysis System

    OpenAIRE

    Yang, Cheng.; Ugbolue, Ukadike C..; Kerr, Andrew.; Stankovic, Vladimir.; Stankovic, Lina.; Carse, Bruce.; Kaliarntas, Konstantinos T..; Rowe, Philip J..

    2016-01-01

    Laboratory-based nonwearable motion analysis systems have significantly advanced with robust objective measurement of the limb motion, resulting in quantified, standardized, and reliable outcome measures compared with traditional, semisubjective, observational gait analysis. However, the requirement for large laboratory space and operational expertise makes these systems impractical for gait analysis at local clinics and homes. In this paper, we focus on autonomous gait event detection with o...

  9. Refined event location and lowered uncertainties in temporal variation of seismic velocity: tackling down the spatial and temporal correlation between elastic and hypocentral parameters in full 4D local earthquake tomography of a geothermal site

    Science.gov (United States)

    Piana Agostinetti, Nicola; Calo', Marco

    2015-04-01

    Temporal variations of the elastic properties of the rocks within a geothermal reservoir have been documented during injection and production phases, using time-repeated 3D local earthquake tomography, LET (e.g. Calo et al., 2011, Gunasekera et al., 2003). However, the magnitude of the variations could be so small that their effects can be masked by observational errors. A common way to reduce the uncertainties in the tomographic models is based on the minimization of the difference between arrival-times of events occurred in the same rock volume, i.e. the so-called Double-difference. In this way: (a) position of the hypocenters is tightly constrained, and (b) residuals in the observed P and S arrival-times are strongly associated with the perturbation of the elastic model more than the perturbation of the hypocentral parameters. Such techniques have been applied to refine the location of the induced seismicity, assuming a time-invariant elastic model between the couples of events. However, this assumption should be carefully considered within the framework of the induced seismicity, where rocks in a geothermal reservoir are heavily stressed and their elastic properties are supposed to change in time. In this study, we investigate the effect of a refined event location on the uncertainties in the velocity model during an injection phase at Soultz geothermal site. First, we perform two synthetic tomographic experiments using travel-times in a given two-phases 3D seismic model, adding a Gaussian noise with a known standard deviation. In the first test, we only use as observed data the absolute P and S arrival times. The tomographic inversion is performed using the trans-dimensional Monte Carlo approach. In the second test, we expanded the Bayesian formulation including the Double-Differences in the data-set. Finally, we present the results for the inversion of the field measurement using a Double-Difference approach with a weighted time-length scale.

  10. Traumatic stress symptomatology after child maltreatment and single traumatic events: different profiles

    NARCIS (Netherlands)

    Jonkman, Caroline S.; Verlinden, Eva; Bolle, Eva A.; Boer, Frits; Lindauer, Ramón J. L.

    2013-01-01

    The sequelae of child maltreatment tend to extend current posttraumatic stress disorder (PTSD) symptoms. This study examined this assumption, hypothesizing that (a) PTSD and trauma-related symptoms are more severe after single trauma than after child maltreatment; (b) symptoms unrelated to trauma

  11. Seismic monitoring at Deception Island volcano (Antarctica): Recent advances

    Science.gov (United States)

    Carmona, E.; Almendros, J.; Martín, R.; Cortés, G.; Alguacil, G.; Moreno, J.; Martín, B.; Martos, A.; Serrano, I.; Stich, D.; Ibáñez, J. M.

    2012-04-01

    Deception Island (South Shetland Island, Antarctica) is an active volcano with recent eruptions (e.g. 1967, 1969 and 1970). It is also among the Antarctic sites most visited by tourists. Besides, there are currently two scientific bases operating during the austral summers, usually from late November to early March. For these reasons it is necessary to deploy a volcano monitoring system as complete as possible, designed specifically to endure the extreme conditions of the volcanic environment and the Antarctic climate. The Instituto Andaluz de Geofísica of University of Granada, Spain (IAG-UGR) performs seismic monitoring on Deception Island since 1994 during austral summer surveys. The seismicity basically includes volcano-tectonic earthquakes, long-period events and volcanic tremor, among other signals. The level of seismicity is moderate, except for a seismo-volcanic crisis in 1999. The seismic monitoring system has evolved during these years, following the trends of the technological developments and software improvements. Recent advances have been mainly focused on: (1) the improvement of the seismic network introducing broadband stations and 24-bit data acquisition systems; (2) the development of a short-period seismic array, with a 12-channel, 24-bit data acquisition system; (3) the implementation of wireless data transmission from the network stations and also from the seismic array to a recording center, allowing for real-time monitoring; (4) the efficiency of the power supply systems and the monitoring of the battery levels and power consumption; (5) the optimization of data analysis procedures, including database management, automated event recognition tools for the identification and classification of seismo-volcanic signals, and apparent slowness vector estimates using seismic array data; (6) the deployment of permanent seismic stations and the transmission of data during the winter using a satellite connection. A single permanent station is operating

  12. Real-time gait event detection for lower limb amputees using a single wearable sensor.

    Science.gov (United States)

    Maqbool, H F; Husman, M A B; Awad, M I; Abouhossein, A; Mehryar, P; Iqbal, N; Dehghani-Sanij, A A

    2016-08-01

    This paper presents a rule-based real-time gait event/phase detection system (R-GEDS) using a shank mounted inertial measurement unit (IMU) for lower limb amputees during the level ground walking. Development of the algorithm is based on the shank angular velocity in the sagittal plane and linear acceleration signal in the shank longitudinal direction. System performance was evaluated with four control subjects (CS) and one transfemoral amputee (TFA) and the results were validated with four FlexiForce footswitches (FSW). The results showed a data latency for initial contact (IC) and toe off (TO) within a range of ± 40 ms for both CS and TFA. A delay of about 3.7 ± 62 ms for a foot-flat start (FFS) and an early detection of -9.4 ± 66 ms for heel-off (HO) was found for CS. Prosthetic side showed an early detection of -105 ± 95 ms for FFS whereas intact side showed a delay of 141 ±73 ms for HO. The difference in the kinematics of the TFA and CS is one of the potential reasons for high variations in the time difference. Overall, detection accuracy was 99.78% for all the events in both groups. Based on the validated results, the proposed system can be used to accurately detect the temporal gait events in real-time that leads to the detection of gait phase system and therefore, can be utilized in gait analysis applications and the control of lower limb prostheses.

  13. Single and multiple cardiovascular biomarkers in subjects without a previous cardiovascular event

    DEFF Research Database (Denmark)

    Pareek, Manan; Bhatt, Deepak L; Vaduganathan, Muthiah

    2017-01-01

    failure, stroke, or all-cause mortality. Predictive capabilities were evaluated using Cox proportional-hazards regression, Harrell's concordance index (C-index), and net reclassification improvement. Median age was 66 (interquartile range: 60-70) years, and 413 (31%) were female. During median 8.......6 (interquartile range: 8.1-9.2) follow-up years, 368 (28%) composite events occurred. NT-proBNP, hs-TnT, GDF-15, and IL-6 were significantly associated with outcome, independently of traditional risk factors, medications, and echocardiography ( p 

  14. SEARCH FOR DARK MATTER IN EVENTS WITH A SINGLE BOSON AND MISSING TRANSVERSE MOMENTUM WITH ATLAS

    CERN Document Server

    Brandt, Oleg; The ATLAS collaboration

    2017-01-01

    The presence of a non-baryonic dark matter component in the Universe is inferred from the observation of its gravitational interaction. If dark matter interacts weakly with the Standard Model it would be produced at the LHC, escaping the detector and leaving a large missing transverse momentum as their signature. The results of searches for Dark Matter with a single boson and large missing transverse momentum in 13 TeV will be presented.

  15. Single event upset tests of a RISC-based fault-tolerant computer

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrough, J.R.; Butner, D.N.; Colella, N.J.; Kaschmitter, J.L.; Shaeffer, D.L.; McKnett, C.L.; Coakley, P.G.; Casteneda, C.

    1996-03-23

    The project successfully demonstrated that dual lock-step comparison of commercial RISC processors is a viable fault-tolerant approach to handling SEU in space environment. The fault tolerant approach on orbit error rate was 38 times less than the single processor error rate. The random nature of the upsets and appearance in critical code section show it is essential to incorporate both hardware and software in the design and operation of fault-tolerant computers.

  16. Quake warnings, seismic culture

    Science.gov (United States)

    Allen, Richard M.; Cochran, Elizabeth S.; Huggins, Tom; Miles, Scott; Otegui, Diego

    2017-01-01

    Since 1990, nearly one million people have died from the impacts of earthquakes. Reducing those impacts requires building a local seismic culture in which residents are aware of earthquake risks and value efforts to mitigate harm. Such efforts include earthquake early warning (EEW) systems that provide seconds to minutes notice of pending shaking. Recent events in Mexico provide an opportunity to assess performance and perception of an EEW system and highlight areas for further improvement. We have learned that EEW systems, even imperfect ones, can help people prepare for earthquakes and build local seismic culture, both beneficial in reducing earthquake-related losses.

  17. Do patients with recurrent episodes of campylobacteriosis differ from those with a single disease event?

    Directory of Open Access Journals (Sweden)

    Michel Pascal

    2011-01-01

    Full Text Available Abstract Background Although Campylobacter is the leading cause of reported bacterial gastro-enteritis in industrialized countries, little is known on its recurrence. The objective of this study is to describe the risk and the patient characteristics of recurrent episodes of human campylobacteriosis reported in Quebec. Methods Laboratory-confirmed cases of campylobacteriosis reported in the province of Quebec, Canada, through ongoing surveillance between 1996 and 2006 were analyzed. The risk of having a recurrent episode of campylobacteriosis was described using life table estimates. Logistic regression was used to assess if gender, age and patient residential location were associated with an increased risk of recurrence. Results Compared to the baseline risk, the risk for a recurrent disease event was higher for a period of four years and followed a decreasing trend. This increased risk of a recurrent event was similar across gender, but higher for people from rural areas and lower for children under four years of age. Conclusions These results may suggest the absence of durable immunity or clinical resilience following a first episode of campylobacteriosis and periodical re-exposure, at least among cases reported through the surveillance system.

  18. Do patients with recurrent episodes of campylobacteriosis differ from those with a single disease event?

    Science.gov (United States)

    2011-01-01

    Background Although Campylobacter is the leading cause of reported bacterial gastro-enteritis in industrialized countries, little is known on its recurrence. The objective of this study is to describe the risk and the patient characteristics of recurrent episodes of human campylobacteriosis reported in Quebec. Methods Laboratory-confirmed cases of campylobacteriosis reported in the province of Quebec, Canada, through ongoing surveillance between 1996 and 2006 were analyzed. The risk of having a recurrent episode of campylobacteriosis was described using life table estimates. Logistic regression was used to assess if gender, age and patient residential location were associated with an increased risk of recurrence. Results Compared to the baseline risk, the risk for a recurrent disease event was higher for a period of four years and followed a decreasing trend. This increased risk of a recurrent event was similar across gender, but higher for people from rural areas and lower for children under four years of age. Conclusions These results may suggest the absence of durable immunity or clinical resilience following a first episode of campylobacteriosis and periodical re-exposure, at least among cases reported through the surveillance system. PMID:21226938

  19. Measurement of s-channel single top-quark production with the ATLAS detector using total event likelihoods

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00333614

    2016-09-21

    A measurement of s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of $8\\,\\mathrm{TeV}$ is presented. The dataset has been recorded with the ATLAS detector at the LHC and corresponds to an integrated luminosity of 20.3$\\,\\mathrm{fb}^{−1}$. Collision events are selected so that a subset of the data is obtained where the signal fraction is relatively high. Selected events contain one isolated electron or muon, missing transverse momentum and 2 jets, both of which are induced by b-quarks. All of these objects have large transverse momenta. The resulting set of events is still dominated by background processes, most notably top-quark pair production and the production of W-bosons in association with jets. In order to further separate the signal from the backgrounds, several approximate event likelihoods are computed. They are based on different hypotheses regarding the scattering process at hand. Together they result in a function of the measured momenta which allows ...

  20. Seismic Data Gathering and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

  1. Liquid Hole-Multipliers: A potential concept for large single-phase noble-liquid TPCs of rare events

    Science.gov (United States)

    Breskin, Amos

    2013-10-01

    A novel concept is proposed for large-volume single-phase noble-liquid TPC detectors for rare events. Both radiation-induced scintillation-light and ionization-charge are detected by Liquid Hole-Multipliers (LHM), immersed in the noble liquid. The latter may consist of cascaded Gas Electron Multipliers (GEM), Thick Gas Electron Multiplier (THGEM) electrodes or others, coated with CsI UV-photocathodes. Electrons, photo-induced on CsI by primary scintillation in the noble liquid, and event-correlated drifting ionization electrons are amplified in the cascaded elements primarily through electroluminescence, and possibly through additional moderate avalanche, occurring within the holes. The resulting charge-signals or light-pulses are recorded on anode pads or with photosensors - e.g. gaseous photomultipliers (GPM), respectively. Potential affordable solutions are proposed for multi-ton dark-matter detectors; open questions are formulated for validating this dream.

  2. Liquid Hole-Multipliers: A potential concept for large single-phase noble-liquid TPCs of rare events

    International Nuclear Information System (INIS)

    Breskin, Amos

    2013-01-01

    A novel concept is proposed for large-volume single-phase noble-liquid TPC detectors for rare events. Both radiation-induced scintillation-light and ionization-charge are detected by Liquid Hole-Multipliers (LHM), immersed in the noble liquid. The latter may consist of cascaded Gas Electron Multipliers (GEM), Thick Gas Electron Multiplier (THGEM) electrodes or others, coated with CsI UV-photocathodes. Electrons, photo-induced on CsI by primary scintillation in the noble liquid, and event-correlated drifting ionization electrons are amplified in the cascaded elements primarily through electroluminescence, and possibly through additional moderate avalanche, occurring within the holes. The resulting charge-signals or light-pulses are recorded on anode pads or with photosensors – e.g. gaseous photomultipliers (GPM), respectively. Potential affordable solutions are proposed for multi-ton dark-matter detectors; open questions are formulated for validating this dream

  3. Multivariate Bayesian decoding of single-trial event-related fMRI responses for memory retrieval of voluntary actions.

    Directory of Open Access Journals (Sweden)

    Dongha Lee

    Full Text Available This study proposes a method for classifying event-related fMRI responses in a specialized setting of many known but few unknown stimuli presented in a rapid event-related design. Compared to block design fMRI signals, classification of the response to a single or a few stimulus trial(s is not a trivial problem due to contamination by preceding events as well as the low signal-to-noise ratio. To overcome such problems, we proposed a single trial-based classification method of rapid event-related fMRI signals utilizing sparse multivariate Bayesian decoding of spatio-temporal fMRI responses. We applied the proposed method to classification of memory retrieval processes for two different classes of episodic memories: a voluntarily conducted experience and a passive experience induced by watching a video of others' actions. A cross-validation showed higher classification performance of the proposed method compared to that of a support vector machine or of a classifier based on the general linear model. Evaluation of classification performances for one, two, and three stimuli from the same class and a correlation analysis between classification accuracy and target stimulus positions among trials suggest that presenting two target stimuli at longer inter-stimulus intervals is optimal in the design of classification experiments to identify the target stimuli. The proposed method for decoding subject-specific memory retrieval of voluntary behavior using fMRI would be useful in forensic applications in a natural environment, where many known trials can be extracted from a simulation of everyday tasks and few target stimuli from a crime scene.

  4. Saharan dust events at the Jungfraujoch: detection by wavelength dependence of the single scattering albedo and first climatology analysis

    Directory of Open Access Journals (Sweden)

    M. Collaud Coen

    2004-01-01

    Full Text Available Scattering and absorption coefficients have been measured continuously at several wavelengths since March 2001 at the high altitude site Jungfraujoch (3580ma.s.l.. From these data, the wavelength dependences of the Ångström exponent and particularly of the single scattering albedo are determined. While the exponent of the single scattering albedo usually increases with wavelength, it decreases with wavelength during Saharan dust events (SDE due to the greater size of the mineral aerosol particles and their different chemical composition. This change in the sign of the single scattering exponent turns out to be a sensitive means for detecting Saharan dust events. The occurrence of SDE detected by this new method was confirmed by visual inspection of filter colors and by studying long-range back-trajectories. An examination of SDE over a 22-month period shows that SDE are more frequent during the March-June period as well as during October and November. The trajectory analysis indicated a mean traveling time of 96.5h, with the most important source countries situated in the northern and north-western part of the Saharan desert. Most of the SDE do not lead to a detectable increase of the 48-h total suspended particulate matter (TSP concentration at the Jungfraujoch. During Saharan dust events, the average contribution of this dust to hourly TSP at the Jungfraujoch is 16µg/m3, which corresponds to an annual mean of 0.8µg/m3 or 24% of TSP.

  5. Analysis of single event transient pulse-width in 65 nm commercial radiation-hardened logic cell

    Science.gov (United States)

    Li, Haisong; Wu, Longsheng; Yang, Bo; Jiang, Yihu

    2017-08-01

    With the critical charge reduced to generate a single event effect (SEE) and high working frequency for a nanometer integrated circuit, the single event effect (SET) becomes increasingly serious for high performance SOC and DSP chips. To analyze the radiation-hardened method of SET for the nanometer integrated circuit, the n+ guard ring and p+ guard ring have been adopted in the layout for a 65 nm commercial radiation-hardened standard cell library. The weakest driving capacity inverter cell was used to evaluate the single event transient (SET) pulse-width distribution. We employed a dual-lane measurement circuit to get more accurate SET’s pulse-width. Six kinds of ions, which provide LETs of 12.5, 22.5, 32.5, 42, 63, and 79.5 {MeV}\\cdot {{cm}}2/{mg}, respectively, have been utilized to irradiate the SET test circuit in the Beijing Tandem Accelerator Nuclear Physics National Laboratory. The testing results reveal that the pulse-width of most SETs is shorter than 400 ps in the range of LETeff from 12.5 {MeV}\\cdot {{cm}}2/{mg} to 79.5 {MeV}\\cdot {{cm}}2/{mg} and the pulse-width presents saturation tendency when the effective linear energy transfer (LETeff) value is larger than 40 {MeV}\\cdot {{cm}}2/{mg}. The test results also show that the hardened commercial standard cell’s pulse-width concentrates on 33 to 264 ps, which decreases by 40% compared to the pulse-width of the 65 nm commercial unhardened standard cell.

  6. Seismic probing of the first dredge-up event through the eccentric red-giant and red-giant spectroscopic binary KIC 9163796. How different are red-giant stars with a mass ratio of 1.015?

    Science.gov (United States)

    Beck, P. G.; Kallinger, T.; Pavlovski, K.; Palacios, A.; Tkachenko, A.; Mathis, S.; García, R. A.; Corsaro, E.; Johnston, C.; Mosser, B.; Ceillier, T.; do Nascimento, J.-D.; Raskin, G.

    2018-04-01

    compared to the sample of typical single field stars. The seismic average of the envelope's rotation agrees with the surface rotation rate. The lithium'abundance is in agreement with quasi rigidly rotating models. Conclusions: The agreement between the surface rotation with the seismic result indicates that the full convective envelope is rotating quasi-rigidly. The models of the lithium abundance are compatible with a rigid rotation in the radiative zone during the main sequence. Because of the many constraints offered by oscillating stars in binary systems, such objects are important test beds of stellar evolution. Based on observations made with the Kepler space telescope and the Hermes spectrograph mounted on the 1.2 m Mercator Telescope at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  7. Quantum theory of single events: Localized de Broglie-wavelets, Schroedinger waves and classical trajectories

    International Nuclear Information System (INIS)

    Barut, A.O.

    1990-06-01

    For an arbitrary potential V with classical trajectories x-vector=g-vector(t) we construct localized oscillating three-dimensional wave lumps ψ(x-vector,t,g-vector) representing a single quantum particle. The crest of the envelope of the ripple follows the classical orbit g-vector(t) slightly modified due to potential V and ψ(x-vector,t;g-vector) satisfies the Schroedinger equation. The field energy, momentum and angular momentum calculated as integrals over all space are equal to particle energy, momentum and angular momentum. The relation to coherent states and to Schroedinger waves are also discussed. (author). 6 refs

  8. Modeling a Single SEP Event from Multiple Vantage Points Using the iPATH Model

    Science.gov (United States)

    Hu, Junxiang; Li, Gang; Fu, Shuai; Zank, Gary; Ao, Xianzhi

    2018-02-01

    Using the recently extended 2D improved Particle Acceleration and Transport in the Heliosphere (iPATH) model, we model an example gradual solar energetic particle event as observed at multiple locations. Protons and ions that are energized via the diffusive shock acceleration mechanism are followed at a 2D coronal mass ejection-driven shock where the shock geometry varies across the shock front. The subsequent transport of energetic particles, including cross-field diffusion, is modeled by a Monte Carlo code that is based on a stochastic differential equation method. Time intensity profiles and particle spectra at multiple locations and different radial distances, separated in longitudes, are presented. The results shown here are relevant to the upcoming Parker Solar Probe mission.

  9. It is highly unlikely that the development of an abdominal wall hernia can be attributable to a single strenuous event.

    Science.gov (United States)

    Pathak, Samir; Poston, Graeme J

    2006-03-01

    There is a commonly held belief that the development of a hernia can be attributed to a single strenuous or traumatic event. Hence, many litigants are successful in compensation claims, causing mounting financial burdens on employers, the courts, insurance companies and the tax-payer. However, there is very little scientific evidence to support this assertion. The aim of this study was to ascertain whether there was any causal link in this process. A total of 133 new patients with 135 abdominal herniae of all varieties (115 inguinal, 3 femoral, 9 umbilical, 4 incisional, and 4 ventral or epigastric), of which 25 were recurrent received structured questionnaires on arrival in the surgical clinic. These questionnaires covered all possible aetiological factors for hernia development (type of work, COAD, smoking, pregnancy, obesity, chronic bladder outflow obstruction, previous surgery including appendicectomy), in addition to any possible attribution to a single strenuous or traumatic event. We then reviewed the GP records in the surgery of all patients who answered positively to the latter possible cause. In the study group, 119 (89%) reported a gradual onset of symptoms. Of the 15 (12 male, 3 female; 11%) who believed that their hernia might be related to a single strenuous or traumatic event, 5 had no other aetiological factors. However, not one of the 15 was found to have contemporaneous forensic medical evidence to support their possible claim. We conclude that we are unable to find any clinical evidence to support the hypothesis that a hernia might develop as the result of one single strenuous or traumatic event. While we accept that this mechanism might still possibly occur, we believe that, at best, it is extremely uncommon. If a medical expert is preparing a report on such a case in a claim for personal injury, then they have a duty to the court to examine carefully all the contemporaneous medical records. If no clinical evidence exists to support the claim

  10. Single event and TREE latchup mitigation for a star tracker sensor: An innovative approach to system level latchup mitigation

    International Nuclear Information System (INIS)

    Kimbrough, J.R.; Colella, N.J.; Davis, R.W.; Bruener, D.B.; Coakley, P.G.; Lutjens, S.W.; Mallon, C.E.

    1994-08-01

    Electronic packages designed for spacecraft should be fault-tolerant and operate without ground control intervention through extremes in the space radiation environment. If designed for military use, the electronics must survive and function in a nuclear radiation environment. This paper presents an innovative ''blink'' approach rather than the typical ''operate through'' approach to achieve system level latchup mitigation on a prototype star tracker camera. Included are circuit designs, flash x-ray test data, and heavy ion data demonstrating latchup mitigation protecting micro-electronics from current latchup and burnout due to Single Event Latchup (SEL) and Transient Radiation Effects on Electronics (TREE)

  11. Search for supersymmetry in events with a single lepton, jets, and missing transverse momentum using a neural network

    CERN Document Server

    Chatterjee, Avishek

    A search for supersymmetry in proton-proton collisions at $\\sqrt{s} = 7$ TeV is presented, focusing on events with a single isolated lepton, energetic jets, and large missing transverse momentum. The analyzed data corresponds to a total integrated luminosity of 4.98 fb$^{−1}$ recorded by the CMS experiment. The search uses an artificial neural network to suppress Standard Model backgrounds, and estimates residual backgrounds using a fully data-driven method. The analysis is performed in both the muon and electron channels, and the combined result is interpreted in terms of limits on the CMSSM parameter space, as well as a simplified model.

  12. Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation

    International Nuclear Information System (INIS)

    Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue

    2014-01-01

    Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)

  13. Single event and TREE latchup mitigation for a star tracker sensor: An innovative approach to system level latchup mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrough, J.R.; Colella, N.J.; Davis, R.W. [Lawrence Livermore National Lab., CA (United States); Bruener, D.B.; Coakley, P.G.; Lutjens, S.W.; Mallon, C.E. [JAYCOR, San Diego, CA (United States)

    1994-08-01

    Electronic packages designed for spacecraft should be fault-tolerant and operate without ground control intervention through extremes in the space radiation environment. If designed for military use, the electronics must survive and function in a nuclear radiation environment. This paper presents an innovative ``blink`` approach rather than the typical ``operate through`` approach to achieve system level latchup mitigation on a prototype star tracker camera. Included are circuit designs, flash x-ray test data, and heavy ion data demonstrating latchup mitigation protecting micro-electronics from current latchup and burnout due to Single Event Latchup (SEL) and Transient Radiation Effects on Electronics (TREE).

  14. Effects of drain-wall in mitigating N-hit single event transient via 45 nm CMOS process

    International Nuclear Information System (INIS)

    Xu, X Y; Tang, M H; Xiao, Y G; Yan, S A; Zhang, W L; Li, Z; Xiong, Y; Zhao, W; Guo, H X

    2015-01-01

    A three-dimensional (3D) technology computer-aided design (TCAD) simulation in a novel layout technique for N-hit single event transient (SET) mitigation based on drain-wall layout technique is proposed. Numerical simulations of both single-device and mixed-mode show that the proposed layout technique designed with 45 nm CMOS process can efficiently reduce not only charge collection but also SET pulse widths (W SET ). What is more, simulations show that impacts caused by part of ion-incidents can be shielded with this novel layout technique. When compared with conventional layout technique and guard drain layout technique, we find that the proposed novel layout technique can provide the best benefit of SET mitigation with a small sacrifice in effective area. (paper)

  15. Seismic risk map for Southeastern Brazil

    International Nuclear Information System (INIS)

    Mioto, J.A.

    1984-01-01

    During the last few years, some studies regarding seismic risk were prepared for three regions of Brazil. They were carried on account of two basic interests: first, toward the seismic history and recurrence of Brazilian seismic events; second, in a way as to provide seismic parameters for the design and construction of hydro and nuclear power plants. The first seismic risk map prepared for the southeastern region was elaborated in 1979 by 6he Universidade de Brasilia (UnB-Brasilia Seismological Station). In 1981 another seismic risk map was completed on the basis of seismotectonic studies carried out for the design and construction of the Nuclear power plants of Itaorna Beach (Angra dos Reis, Rio de Janeiro) by IPT (Mining and Applied Geology Division). In Brazil, until 1984, seismic studies concerning hydro and nuclear power plants and other civil construction of larger size did not take into account the seismic events from the point of view of probabilities of seismic recurrences. Such analysis in design is more important than the choice of a level of intensity or magnitude, or adoption of a seismicity level ased on deterministic methods. In this way, some considerations were made, concerning the use of seisms in Brazilian designs of hydro and nuclear power plants, as far as seismic analysis is concerned, recently altered over the current seismic risk panorama. (D.J.M.) [pt

  16. Sources of Error and the Statistical Formulation of Ms mb Seismic Event Screening Analysis for the Comprehensive Nuclear-Test-Ban Treaty (CTBT)

    Science.gov (United States)

    2011-09-01

    force. Under the CTBT, a monitoring system of seismic, hydroacoustic , infrasonic and radionuclide sensors operates and data from this system is analyzed...7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Los Alamos National Laboratory ,P.O. Box 1663 ,Los Alamos,NM,87545 8. PERFORMING ORGANIZATION...Air Force Research Laboratory (AFRL) and the National Nuclear Security Administration (NNSA). U.S. Government or Federal Rights License 14. ABSTRACT

  17. Accuracy of the master-event and double-difference locations: synthetic tests and application to seismicity in West Bohemia, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Bouchaala, Fateh; Vavryčuk, Václav; Fischer, Tomáš

    2013-01-01

    Roč. 17, č. 3 (2013), s. 841-859 ISSN 1383-4649 R&D Projects: GA AV ČR IAA300120905; GA ČR(CZ) GAP210/12/1491; GA MŠk LM2010008 EU Projects: European Commission(XE) 230669 - AIM Institutional support: RVO:67985530 Keywords : earthquakes * earthquake swarm * faults * locations * seismicity Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.386, year: 2013

  18. The 2017 Maple Creek Seismic Swarm in Yellowstone National Park

    Science.gov (United States)

    Pang, G.; Hale, J. M.; Farrell, J.; Burlacu, R.; Koper, K. D.; Smith, R. B.

    2017-12-01

    The University of Utah Seismograph Stations (UUSS) performs near-real-time monitoring of seismicity in the region around Yellowstone National Park in partnership with the United States Geological Survey and the National Park Service. UUSS operates and maintains 29 seismic stations with network code WY (short-period, strong-motion, and broadband) and records data from five other seismic networks—IW, MB, PB, TA, and US—to enhance the location capabilities in the Yellowstone region. A seismic catalog is produced using a conventional STA/LTA detector and single-event location techniques (Hypoinverse). On June 12, 2017, a seismic swarm began in Yellowstone National Park about 5 km east of Hebgen Lake. The swarm is adjacent to the source region of the 1959 MW 7.3 Hebgen Lake earthquake, in an area corresponding to positive Coulumb stress change from that event. As of Aug. 1, 2017, the swarm consists of 1481 earthquakes with 1 earthquake above magnitude 4, 8 earthquakes in the magnitude 3 range, 115 earthquakes in the magnitude 2 range, 469 earthquakes in the magnitude 1 range, 856 earthquakes in the magnitude 0 range, 22 earthquakes with negative magnitudes, and 10 earthquakes with no magnitude. Earthquake depths are mostly between 3 and 10 km and earthquake depth increases toward the northwest. Moment tensors for the 2 largest events (3.6 MW and 4.4. MW) show strike-slip faulting with T axes oriented NE-SW, consistent with the regional stress field. We are currently using waveform cross-correlation methods to measure differential travel times that are being used with the GrowClust program to generate high-accuracy relative relocations. Those locations will be used to identify structures in the seismicity and make inferences about the tectonic and magmatic processes causing the swarm.

  19. Comparison of analytical models and experimental results for single-event upset in CMOS SRAMs

    International Nuclear Information System (INIS)

    Mnich, T.M.; Diehl, S.E.; Shafer, B.D.

    1983-01-01

    In an effort to design fully radiation-hardened memories for satellite and deep-space applications, a 16K and a 2K CMOS static RAM were modeled for single-particle upset during the design stage. The modeling resulted in the addition of a hardening feedback resistor in the 16K remained tentatively unaltered. Subsequent experiments, using the Lawrence Berkeley Laboratories' 88-inch cyclotron to accelerate krypton and oxygen ions, established an upset threshold for the 2K and the 16K without resistance added, as well as a hardening threshold for the 16K with feedback resistance added. Results for the 16K showed it to be hardenable to the higher level than previously published data for other unhardened 16K RAMs. The data agreed fairly well with the modeling results; however, a close look suggests that modification of the simulation methodology is required to accurately predict the resistance necessary to harden the RAM cell

  20. Seismogenic zonation and seismic hazard estimates in a Southern Italy area (Northern Apulia characterised by moderate seismicity rates

    Directory of Open Access Journals (Sweden)

    V. Del Gaudio

    2009-02-01

    Full Text Available The northernmost part of Apulia, in Southern Italy, is an emerged portion of the Adriatic plate, which in past centuries was hit by at least three disastrous earthquakes and at present is occasionally affected by seismic events of moderate energy. In the latest seismic hazard assessment carried out in Italy at national scale, the adopted seismogenic zonation (named ZS9 has defined for this area a single zone including parts of different structural units (chain, foredeep, foreland. However significant seismic behaviour differences were revealed among them by our recent studies and, therefore, we re-evaluated local seismic hazard by adopting a zonation, named ZNA, modifying the ZS9 to separate areas of Northern Apulia belonging to different structural domains. To overcome the problem of the limited datasets of historical events available for small zones having a relatively low rate of earthquake recurrence, an approach was adopted that integrates historical and instrumental event data. The latter were declustered with a procedure specifically devised to process datasets of low to moderate magnitude shocks. Seismicity rates were then calculated following alternative procedural choices, according to a "logic tree" approach, to explore the influence of epistemic uncertainties on the final results and to evaluate, among these, the importance of the uncertainty in seismogenic zonation. The comparison between the results obtained using zonations ZNA and ZS9 confirms the well known "spreading effect" that the use of larger seismogenic zones has on hazard estimates. This effect can locally determine underestimates or overestimates by amounts that make necessary a careful reconsideration of seismic classification and building code application.

  1. Single event transient modeling and mitigation techniques for mixed-signal delay locked loop (DLL) and clock circuits

    Science.gov (United States)

    Maillard, Pierre

    The purpose of this PhD work has been to investigate, model, test, develop and provide hardening techniques and guidelines for the mitigation of single event transients (SETs) in analog mixed-signal (AMS) delay locked loops (DLLs) for radiation-hardened applications. Delay-locked-loops (DLLs) are circuit substructures that are present in complex ASIC and system-on-a-chip designs. These circuits are widely used in on-chip clock distribution systems to reduce clock skew, to reduce jitter noise, and to recover clock signals at regional points within a global clock distribution system. DLLs are critical to the performance of many clock distribution systems, and in turn, the overall performance of the associated integrated system; as such, complex systems often employ multiple DLLs for clock deskew and distribution tasks. In radiation environments such as on-orbit, these critical circuits represent at-risk points of malfunction for large sections of integrated circuits due to vulnerabilities to radiation-generated transients (i.e. single event transients) that fan out across the system. The analysis of single event effects in analog DLLs has shown that each DLL sub-circuit primitive is vulnerable to single event transients. However, we have identified the voltage controlled delay line (VCDL) sub-circuit as the most sensitive to radiation-induced single event effects generating missing clock pulses that increase with the operating frequency of the circuit. This vulnerability increases with multiple instantiation of DLLs as clock distribution nodes throughout an integrated system on a chip. To our knowledge, no complete work in the rad-hard community regarding the hardening of mixed-signal DLLs against single event effects (missing pulses) has been developed. Most of the work present in the literature applies the "brute force" and well-established digital technique of triple modular redundancy (TMR) to the digital subcomponents. We have developed two novel design

  2. Single-Event Effects in Power MOSFETs During Heavy Ion Irradiations Performed After Gamma-Ray Degradation

    Science.gov (United States)

    Busatto, G.; De Luca, V.; Iannuzzo, F.; Sanseverino, A.; Velardi, F.

    2013-10-01

    The robustness of commercial power metal-oxide semiconductor field-effect transistors to combined gamma-heavy ion irradiation has been investigated, evidence that the degradation of the gate oxide caused by the γ irradiation can severely corrupt the robustness to single-event effects and drastically modify the physical behavior of the device under test after the impact of a heavy ion. A decrease of the critical voltages at which destructive burnouts and gate ruptures for heavy ion impact appear, has been detected in the devices under test, which were previously irradiated with γ rays. In addition, the amount of critical voltage reduction is strictly related to the amount of the absorbed γ-ray dose. Furthermore, at the failure voltage, the behavior of the device is affected by the conduction of a current through the gate oxide. Moreover, the single-event gate rupture” of the device appears at lower voltages because of the reduction of the Fowler-Nordheim limit in the γ-irradiated devices.

  3. Models of synchronized hippocampal bursts in the presence of inhibition. I. Single population events.

    Science.gov (United States)

    Traub, R D; Miles, R; Wong, R K

    1987-10-01

    1. We constructed model networks with 520 or 1,020 cells intended to represent the CA3 region of the hippocampus. Model neurons were simulated in enough detail to reproduce intrinsic bursting and the electrotonic flow of currents along dendritic cables. Neurons exerted either excitatory or inhibitory postsynaptic actions on other cells. The network models were simulated with different levels of excitatory and inhibitory synaptic strengths in order to study epileptic and other interesting collective behaviors in the system. 2. Excitatory synapses between neurons in the network were powerful enough so that burst firing in a presynaptic neuron would evoke bursting in its connected cells. Since orthodromic or antidromic stimulation evokes both a fast and a slow phase of inhibition, two types of inhibitory cells were simulated. The properties of these inhibitory cells were modeled to resemble those of two types of inhibitory cells characterized by dual intracellular recordings in the slice preparation. 3. With fast inhibition totally blocked, a stimulus to a single cell lead to a synchronized population burst. Thus the principles of our epileptic synchronization model, developed earlier, apply even when slow inhibitory postsynaptic potentials (IPSPs) are present, as apparently occurs in the epileptic hippocampal slice. The model performs in this way because bursting can propagate through several generations in the network before slow inhibition builds up enough to block burst propagation. This can occur, however, only if connectivity is sufficiently large. With very low connection densities, slow IPSPs will prevent the development of full synchronization. 4. We performed multiple simulations in which the fast inhibitory conductance strength was kept fixed at various levels while the strength of the excitatory synapses was varied. In each simulation, we stimulated either one or four cells. For each level of inhibition, the peak number of cells bursting depended

  4. Role of multisensory stimuli in vigilance enhancement- a single trial event related potential study.

    Science.gov (United States)

    Abbasi, Nida Itrat; Bodala, Indu Prasad; Bezerianos, Anastasios; Yu Sun; Al-Nashash, Hasan; Thakor, Nitish V

    2017-07-01

    Development of interventions to prevent vigilance decrement has important applications in sensitive areas like transportation and defence. The objective of this work is to use multisensory (visual and haptic) stimuli for cognitive enhancement during mundane tasks. Two different epoch intervals representing sensory perception and motor response were analysed using minimum variance distortionless response (MVDR) based single trial ERP estimation to understand the performance dependency on both factors. Bereitschaftspotential (BP) latency L3 (r=0.6 in phase 1 (visual) and r=0.71 in phase 2 (visual and haptic)) was significantly correlated with reaction time as compared to that of sensory ERP latency L2 (r=0.1 in both phase 1 and phase 2). This implies that low performance in monotonous tasks is predominantly dependent on the prolonged neural interaction with the muscles to initiate movement. Further, negative relationship was found between the ERP latencies related to sensory perception and Bereitschaftspotential (BP) and occurrence of epochs when multisensory cues are provided. This means that vigilance decrement is reduced with the help of multisensory stimulus presentation in prolonged monotonous tasks.

  5. Classification of Single-Trial Auditory Events Using Dry-Wireless EEG During Real and Motion Simulated Flight

    Directory of Open Access Journals (Sweden)

    Daniel eCallan

    2015-02-01

    Full Text Available Application of neuro-augmentation technology based on dry-wireless EEG may be considerably beneficial for aviation and space operations because of the inherent dangers involved. In this study we evaluate classification performance of perceptual events using a dry-wireless EEG system during motion platform based flight simulation and actual flight in an open cockpit biplane to determine if the system can be used in the presence of considerable environmental and physiological artifacts. A passive task involving 200 random auditory presentations of a chirp sound was used for evaluation. The advantage of this auditory task is that it does not interfere with the perceptual motor processes involved with piloting the plane. Classification was based on identifying the presentation of a chirp sound versus silent periods. Evaluation of Independent component analysis and Kalman filtering to enhance classification performance by extracting brain activity related to the auditory event from other non-task related brain activity and artifacts was assessed. The results of permutation testing revealed that single trial classification of presence or absence of an auditory event was significantly above chance for all conditions on a novel test set. The best performance could be achieved with both ICA and Kalman filtering relative to no processing: Platform Off (83.4% vs 78.3%, Platform On (73.1% vs 71.6%, Biplane Engine Off (81.1% vs 77.4%, and Biplane Engine On (79.2% vs 66.1%. This experiment demonstrates that dry-wireless EEG can be used in environments with considerable vibration, wind, acoustic noise, and physiological artifacts and achieve good single trial classification performance that is necessary for future successful application of neuro-augmentation technology based on brain-machine interfaces.

  6. Classification of single-trial auditory events using dry-wireless EEG during real and motion simulated flight.

    Science.gov (United States)

    Callan, Daniel E; Durantin, Gautier; Terzibas, Cengiz

    2015-01-01

    Application of neuro-augmentation technology based on dry-wireless EEG may be considerably beneficial for aviation and space operations because of the inherent dangers involved. In this study we evaluate classification performance of perceptual events using a dry-wireless EEG system during motion platform based flight simulation and actual flight in an open cockpit biplane to determine if the system can be used in the presence of considerable environmental and physiological artifacts. A passive task involving 200 random auditory presentations of a chirp sound was used for evaluation. The advantage of this auditory task is that it does not interfere with the perceptual motor processes involved with piloting the plane. Classification was based on identifying the presentation of a chirp sound vs. silent periods. Evaluation of Independent component analysis (ICA) and Kalman filtering to enhance classification performance by extracting brain activity related to the auditory event from other non-task related brain activity and artifacts was assessed. The results of permutation testing revealed that single trial classification of presence or absence of an auditory event was significantly above chance for all conditions on a novel test set. The best performance could be achieved with both ICA and Kalman filtering relative to no processing: Platform Off (83.4% vs. 78.3%), Platform On (73.1% vs. 71.6%), Biplane Engine Off (81.1% vs. 77.4%), and Biplane Engine On (79.2% vs. 66.1%). This experiment demonstrates that dry-wireless EEG can be used in environments with considerable vibration, wind, acoustic noise, and physiological artifacts and achieve good single trial classification performance that is necessary for future successful application of neuro-augmentation technology based on brain-machine interfaces.

  7. Probabilistic Seismic Hazard Analysis for Yemen

    Directory of Open Access Journals (Sweden)

    Rakesh Mohindra

    2012-01-01

    Full Text Available A stochastic-event probabilistic seismic hazard model, which can be used further for estimates of seismic loss and seismic risk analysis, has been developed for the territory of Yemen. An updated composite earthquake catalogue has been compiled using the databases from two basic sources and several research publications. The spatial distribution of earthquakes from the catalogue was used to define and characterize the regional earthquake source zones for Yemen. To capture all possible scenarios in the seismic hazard model, a stochastic event set has been created consisting of 15,986 events generated from 1,583 fault segments in the delineated seismic source zones. Distribution of horizontal peak ground acceleration (PGA was calculated for all stochastic events considering epistemic uncertainty in ground-motion modeling using three suitable ground motion-prediction relationships, which were applied with equal weight. The probabilistic seismic hazard maps were created showing PGA and MSK seismic intensity at 10% and 50% probability of exceedance in 50 years, considering local soil site conditions. The resulting PGA for 10% probability of exceedance in 50 years (return period 475 years ranges from 0.2 g to 0.3 g in western Yemen and generally is less than 0.05 g across central and eastern Yemen. The largest contributors to Yemen’s seismic hazard are the events from the West Arabian Shield seismic zone.

  8. Innovative Approaches for Seismic Studies of Mars (Invited)

    Science.gov (United States)

    Banerdt, B.

    2010-12-01

    (which can supply up to 1010 J of kinetic energy), seismic “hum” from meteorological forcing, and tidal deformation from Phobos (with a period around 6 hours). Another means for encouraging a seismic mission to Mars is to promote methods that can derive interior information from a single seismometer. Fortunately many such methods exist, including source location through P-S and back-azimuth, receiver functions, identification of later phases (PcP, PKP, etc.), surface wave dispersion, and normal mode analysis (from single large events, stacked events, or background noise). Such methods could enable the first successful seismic investigation of another planet since the Apollo seismometers were turned off almost 35 years ago.

  9. Total ionizing dose (TID) effect and single event effect (SEE) in quasi-SOI nMOSFETs

    International Nuclear Information System (INIS)

    Tan, Fei; Huang, Ru; An, Xia; Wu, Weikang; Feng, Hui; Huang, Liangxi; Fan, Jiewen; Zhang, Xing; Wang, Yangyuan

    2014-01-01

    This paper studies the total ionizing dose (TID) and single event effect (SEE) in quasi-SOI nMOSFETs for the first time. After exposure to gamma rays, the off-state leakage current (I off ) of a quasi-SOI device increases with the accumulating TID, and the on-state bias configuration is shown to be the worst-case bias configuration during irradiation. Although an additional TID-sensitive region is introduced by the unique structure of the quasi-SOI device, the influence of positive charge trapped in L-type oxide layers on the degradation of device performance is neglectable. Since the TID-induced leakage path in the quasi-SOI device is greatly reduced due to the isolation of L-type oxide layers, the TID-induced I off  degradation in the quasi-SOI device is greatly suppressed. In addition, 3D simulation is performed to investigate the SEE of the quasi-SOI device. The full-width at half-maximum (FWHM) of worst-case drain current transient and collected charges of the quasi-SOI device after single-ion-striking is smaller than in a bulk Si device, indicating that the quasi-SOI device inherits the advantage of an SOI device in single event transient immunity. Therefore, the quasi-SOI device, which has improved electrical properties and radiation-hardened characteristics for both TID and SEE, can be considered as one of the promising candidates for space applications. (paper)

  10. Savannah River Site disaggregated seismic spectra

    International Nuclear Information System (INIS)

    Stephenson, D.E.

    1993-02-01

    The objective of this technical note is to characterize seismic ground motion at the Savannah River Site (SRS) by postulated earthquakes that may impact facilities at the site. This task is accomplished by reviewing the deterministic and probabilistic assessments of the seismic hazard to establish the earthquakes that control the hazard to establish the earthquakes that control the hazard at the site and then evaluate the associated seismic ground motions in terms of response spectra. For engineering design criteria of earthquake-resistant structures, response spectra serve the function of characterizing ground motions as a function of period or frequency. These motions then provide the input parameters that are used in the analysis of structural response. Because they use the maximum response, the response spectra are an inherently conservative design tool. Response spectra are described in terms of amplitude, duration, and frequency content, and these are related to source parameters, travel path, and site conditions. Studies by a number of investigators have shown by statistical analysis that for different magnitudes the response spectrum values are different for differing periods. These facts support Jennings' position that using different shapes of design spectra for earthquakes of different magnitudes and travel paths is a better practice than employing a single, general-purpose shape. All seismic ground motion characterization results indicate that the PGA is controlled by a local event with M w < 6 and R < 30km. The results also show that lower frequencies are controlled by a larger, more distant event, typically the Charleston source. The PGA of 0.2 g, based originally on the Blume study, is consistent with LLNL report UCRL-15910 (1990) and with the DOE position on LLNL/EPRI

  11. Characterization of System on a Chip (SoC) Single Event Upset (SEU) Responses Using SEU Data, Classical Reliability Models, and Space Environment Data

    Science.gov (United States)

    Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

    2017-01-01

    We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

  12. Analyzing Test-As-You-Fly Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

    Science.gov (United States)

    Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

    2017-01-01

    We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

  13. Mitigating the consequences of extreme events on strategic facilities: evaluation of volcanic and seismic risk affecting the Caspian oil and gas pipelines in the Republic of Georgia.

    Science.gov (United States)

    Pasquarè, F A; Tormey, D; Vezzoli, L; Okrostsvaridze, A; Tutberidze, B

    2011-07-01

    In this work we identify and quantify new seismic and volcanic risks threatening the strategic Caspian oil and gas pipelines through the Republic of Georgia, in the vicinity of the recent Abuli Samsari Volcanic Ridge, and evaluate risk reduction measures, mitigation measures, and monitoring. As regards seismic risk, we identified a major, NW-SE trending strike-slip fault; based on the analysis of fault planes along this major transcurrent structure, an about N-S trend of the maximum, horizontal compressive stress (σ1) was determined, which is in good agreement with data instrumentally derived after the 1986, M 5.6 Paravani earthquake and its aftershock. Particularly notable is the strong alignment of volcanic vents along an about N-S trend that suggests a magma rising controlled by the about N-S-directed σ1. The original pipeline design included mitigation measures for seismic risk and other geohazards, including burial of the pipeline for its entire length, increased wall thickness, block valve spacing near recognized hazards, and monitoring of known landslide hazards. However, the design did not consider volcanic risk or the specific seismic hazards revealed by this study. The result of our analysis is that the Baku-Tbilisi-Ceyhan (BTC) oil pipeline, as well as the Baku-Tbilisi-Erzerum South Caucasian natural gas pipeline (SCP) were designed in such a way that they significantly reduce the risk posed by the newly-identified geohazards in the vicinity of the Abuli-Samsari Ridge. No new measures are recommended for the pipeline itself as a result of this study. However, since the consequences of long-term shut-down would be very damaging to the economies of Western Europe, we conclude that the regionally significant BTC and SCP warrant greater protections, described in the final section of or work. The overall objective of our effort is to present the results in a matrix framework that allows the technical information to be used further in the decision

  14. Data processing of natural and induced events recorded at the seismic station Ostrava-Kr¨¢sn¨¦ Pole (OKC)

    OpenAIRE

    Nov¨¢k Josef; Rušajov¨¢ Jana; Holub Karel; Kejzl¨ªk Jarom¨ªr

    2001-01-01

    The operation of the seismic station Ostrava-Kr¨¢sn¨¦ Pole (OKC) (¦Õ = 49.8352¡ãN; ¦Ë = 18.1422¡ãE) which is situated at present in an experimental gallery nearby the Ostrava planetarium started in the year 1983 being equiped initially by analogue instrumentation. Modernization of instrumentation at the station was aimed at the installation of a new digital data acquisition system and the respective software packages for data interpretation and transmission.Data acquisition system VISTEC is b...

  15. Meteoroid impacts as seismic sources on Mars

    Science.gov (United States)

    Davis, Paul M.

    1993-10-01

    Lunar Apollo seismic experiment results reflecting asteroid fragment impacts are presently used to estimate the seismic signals that can be expected on Mars, with allowances for impact-rate differences due to a different impactor population, and the combined effect of ablation and deceleration in the Martian atmosphere on impact energy. The entry flux at Mars is 2.6 times that at the earth. The net result for such seismic activity, which has an uncertainty factor of 3, is that the number of large impacts/year detected at a Mars seismic station comparable to Apollo's in sensitivity will be 116 events/year, compared to the moon's 76 events/year.

  16. Mine seismicity and the Comprehensive Nuclear Test Ban Treaty

    Energy Technology Data Exchange (ETDEWEB)

    Chiappetta, F. [Blasting Analysis International, Allentown, PA (United States); Heuze, F.; Walter, W. [Lawrence Livermore National Lab., CA (United States); Hopler, R. [Powderman Consulting Inc., Oxford, MD (United States); Hsu, V. [Air Force Technical Applications Center, Patrick AFB, FL (United States); Martin, B. [Thunder Basin Coal Co., Wright, WY (United States); Pearson, C. [Los Alamos National Lab., NM (United States); Stump, B. [Southern Methodist Univ., Dallas, TX (United States); Zipf, K. [Univ. of New South Wales (Australia)

    1998-12-09

    Surface and underground mining operations generate seismic ground motions which are created by chemical explosions and ground failures. It may come as a surprise to some that the ground failures (coal bumps, first caves, pillar collapses, rockbursts, etc.) can send signals whose magnitudes are as strong or stronger than those from any mining blast. A verification system that includes seismic, infrasound, hydroacoustic and radionuclide sensors is being completed as part of the CTBT. The largest mine blasts and ground failures will be detected by this system and must be identified as distinct from signals generated by small nuclear explosions. Seismologists will analyze the seismic records and presumably should be able to separate them into earthquake-like and non earthquake-like categories, using a variety of so-called seismic discriminants. Non-earthquake essentially means explosion- or implosion-like. Such signals can be generated not only by mine blasts but also by a variety of ground failures. Because it is known that single-fired chemical explosions and nuclear explosion signals of the same yield give very similar seismic records, the non-earthquake signals will be of concern to the Treaty verification community. The magnitude of the mine-related events is in the range of seismicity created by smaller nuclear explosions or decoupled tests, which are of particular concern under the Treaty. It is conceivable that legitimate mining blasts or some mine-induced ground failures could occasionally be questioned. Information such as shot time, location and design parameters may be all that is necessary to resolve the event identity. In rare instances where the legitimate origin of the event could not be resolved by a consultation and clarification procedure, it might trigger on On-Site Inspection (OSI). Because there is uncertainty in the precise location of seismic event as determined by the International Monitoring System (IMS), the OSI can cover an area of up to 1

  17. Seismic waves and seismic barriers

    Science.gov (United States)

    Kuznetsov, S. V.

    2011-05-01

    The basic idea of seismic barrier is to protect an area occupied by a building or a group of buildings from seismic waves. Depending on nature of seismic waves that are most probable in a specific region, different kinds of seismic barriers are suggested. For example, vertical barriers resembling a wall in a soil can protect from Rayleigh and bulk waves. The FEM simulation reveals that to be effective, such a barrier should be (i) composed of layers with contrast physical properties allowing "trapping" of the wave energy inside some of the layers, and (ii) depth of the barrier should be comparable or greater than the considered seismic wave length. Another type of seismic barrier represents a relatively thin surface layer that prevents some types of surface seismic waves from propagating. The ideas for these barriers are based on one Chadwick's result concerning non-propagation condition for Rayleigh waves in a clamped half-space, and Love's theorem that describes condition of non-existence for Love waves. The numerical simulations reveal that to be effective the length of the horizontal barriers should be comparable to the typical wavelength.

  18. Seismic fragility analyses

    International Nuclear Information System (INIS)

    Kostov, Marin

    2000-01-01

    In the last two decades there is increasing number of probabilistic seismic risk assessments performed. The basic ideas of the procedure for performing a Probabilistic Safety Analysis (PSA) of critical structures (NUREG/CR-2300, 1983) could be used also for normal industrial and residential buildings, dams or other structures. The general formulation of the risk assessment procedure applied in this investigation is presented in Franzini, et al., 1984. The probability of failure of a structure for an expected lifetime (for example 50 years) can be obtained from the annual frequency of failure, β E determined by the relation: β E ∫[d[β(x)]/dx]P(flx)dx. β(x) is the annual frequency of exceedance of load level x (for example, the variable x may be peak ground acceleration), P(fI x) is the conditional probability of structure failure at a given seismic load level x. The problem leads to the assessment of the seismic hazard β(x) and the fragility P(fl x). The seismic hazard curves are obtained by the probabilistic seismic hazard analysis. The fragility curves are obtained after the response of the structure is defined as probabilistic and its capacity and the associated uncertainties are assessed. Finally the fragility curves are combined with the seismic loading to estimate the frequency of failure for each critical scenario. The frequency of failure due to seismic event is presented by the scenario with the highest frequency. The tools usually applied for probabilistic safety analyses of critical structures could relatively easily be adopted to ordinary structures. The key problems are the seismic hazard definitions and the fragility analyses. The fragility could be derived either based on scaling procedures or on the base of generation. Both approaches have been presented in the paper. After the seismic risk (in terms of failure probability) is assessed there are several approaches for risk reduction. Generally the methods could be classified in two groups. The

  19. New method for selection and characterization of single-source events in Ni+Ni collisions at 32 A.MeV

    International Nuclear Information System (INIS)

    Maskay-Wallez, Anne-Marie

    1999-01-01

    The study of heavy ion collisions, with the help of such efficient multi-detectors as INDRA, has shown the persistence of reactions leading to single-source events, up to bombarding energies higher than the Fermi one. These events could help characterizing an expected phase transition in nuclear matter. Whatever interesting they may be, the single-source events correspond to a small part of the total cross section, which makes them difficult to isolate and therefore to analyze. That is why different selection means have been tested - thanks to the 'Simon' event generator - on a simulated Ni + Ni at 32 A·MeV sample, before any application to the INDRA experimental data. As the known methods based on global variables did not prove effective, a set of new 4-dimensional quantities has been built, whose main advantage lies in a better description of physical events. From a Discriminant Analysis performed on 625 of these new 'moments' proceeds a highly discriminant variable, called D 625 . The experimental cross section associated with D 625 -selected single-source events amounts to 170 mb at 32 A·MeV. Such quasi-fusion events are shown to disappear at about 60 A·MeV. As regards the deexcitation mode of the 32 A·MeV Ni + Ni single-source events, an extensive experimental study and comparisons of the data with two reference models seem to confirm the hypothesis of a transition between fusion-evaporation and simultaneous multifragmentation mechanisms. (author)

  20. Seismicity, seismology and erosion

    Science.gov (United States)

    Hovius, Niels; Meunier, Patrick; Burtin, Arnaud; Marc, Odin

    2013-04-01

    At the interface of geomorphology and seismology, patterns of erosion can be used to constrain seismic processes, and seismological instruments to determine geomorphic activity. For example, earthquakes trigger mass wasting in proportion to peak ground velocity or acceleration, modulated by local geologic and topographic conditions. This geomorphic response determines the mass balance and net topographic effect of earthquakes. It can also be used to obtain information about the distribution of seismic slip where instrumental observations are not available. Equally, seismometers can register the signals of geomorphic processes, revealing their location, type and magnitude. The high temporal resolution of such records can help determine the exact meteorological conditions that gave rise to erosion events, and the interactions between individual surface processes during such events. We will illustrate this synergy of disciplines with examples from active mountain belts around the world, including Taiwan, Japan, Papua New Guinea and the Alps.

  1. Seismic detectability of meteorite impacts on Europa

    Science.gov (United States)

    Tsuji, Daisuke; Teanby, Nicholas

    2016-04-01

    Europa, the second of Jupiter's Galilean satellites, has an icy outer shell, beneath which there is probably liquid water in contact with a rocky core. Europa, may thus provide an example of a sub-surface habitable environment so is an attractive object for future lander missions. In fact, the Jupiter Icy Moon Explorer (JUICE) mission has been selected for the L1 launch slot of ESA's Cosmic Vision science programme with the aim of launching in 2022 to explore Jupiter and its potentially habitable icy moons. One of the best ways to probe icy moon interiors in any future mission will be with a seismic investigation. Previously, the Apollo seismic experiment, installed by astronauts, enhanced our knowledge of the lunar interior. For a recent mission, NASA's 2016 InSight Mars lander aims to obtain seismic data and will deploy a seismometer directly onto Mars' surface. Motivated by these works, in this study we show how many meteorite impacts will be detected using a single seismic station on Europa, which will be useful for planning the next generation of outer solar system missions. To this end, we derive: (1) the current small impact flux on Europa from Jupiter impact rate models; (2) a crater diameter versus impactor energy scaling relation for ice by merging previous experiments and simulations; (3) scaling relations for seismic signals as a function of distance from an impact site for a given crater size based on analogue explosive data obtained on Earth's icy surfaces. Finally, resultant amplitudes are compared to the noise level of a likely seismic instrument (based on the NASA InSight mission seismometers) and the number of detectable impacts are estimated. As a result, 0.5-3.0 local/regional small impacts (i.e., direct P-waves through the ice crust) are expected to be detected per year, while global-scale impact events (i.e., PKP-waves refracted through the mantle) are rare and unlikely to be detected by a short duration mission. We note that our results are

  2. [Incidence rate of adverse reaction/event by Qingkailing injection: a Meta-analysis of single rate].

    Science.gov (United States)

    Ai, Chun-ling; Xie, Yan-ming; Li, Ming-quan; Wang, Lian-xin; Liao, Xing

    2015-12-01

    To systematically review the incidence rate of adverse drug reaction/event by Qingkailing injection. Such databases as the PubMed, EMbase, the Cochrane library, CNKI, VIP WanFang data and CBM were searched by computer from foundation to July 30, 2015. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and cross check data. Then, Meta-analysis was performed by using the R 3.2.0 software, subgroup sensitivity analysis was performed based on age, mode of medicine, observation time and research quality. Sixty-three studies involving 9,793 patients with Qingkailing injection were included, 367 cases of adverse reactions/events were reported in total. The incidence rate of adverse reaction in skin and mucosa group was 2% [95% CI (0.02; 0.03)]; the digestive system adverse reaction was 6% [95% CI(0.05; 0.07); the injection site adverse reaction was 4% [95% CI (0.02; 0.07)]. In the digestive system as the main types of adverse reactions/events, incidence of children and adults were 4.6% [0.021 1; 0.097 7] and 6.9% [0.053 5; 0.089 8], respectively. Adverse reactions to skin and mucous membrane damage as the main performance/event type, the observation time > 7 days and ≤ 7 days incidence of 3% [0.012 9; 0.068 3] and 1.9% [0.007 8; 0.046 1], respectively. Subgroup analysis showed that different types of adverse reactions, combination in the incidence of adverse reactions/events were higher than that of single drug, the difference was statistically significant (P reactions occur, and clinical rational drug use, such as combination, age and other fators, and the influence factors vary in different populations. Therefore, clinical doctors for children and the elderly use special care was required for a clear and open spirit injection, the implementation of individualized medication.

  3. Analysis of using protons in secondary beam on BEPC as a particle source in single event effects experiment study

    International Nuclear Information System (INIS)

    He Chaohui; Li Guozheng; Liu Enke

    1999-01-01

    The energy range and yield of the protons in the secondary beam on BEPC are first analyzed, at the point of using the protons as a particle source in the single event effects (SEE) experiment of semiconductor devices. The energy ranges of the proton produced by high energy electrons bombarding on targets in three methods are calculated and the corresponding cross sections are estimated. The cross section of producing protons can be increased by using heavy nucleus target and the differential yield of protons can reach 1.66 x 10 -3 s -1 ·sr -1 ·eV -1 . The protons can be used in SEE experiment of the semiconductor devices with the high SEE cross sections

  4. Proton-induced single event upset characterisation of a 1 giga-sample per second analog to digital converter

    International Nuclear Information System (INIS)

    Reed, R.A.; Marshall, P.W.; Carts, M.A.

    1999-01-01

    The SPT7760 is an analog to digital converter that is used in satellite for digital processing. In this paper we describe the characterization and analysis of proton-induced single event upsets (SEU) for the SPT7760 operating at sample rates from 125 Msps (Mega-samples per second) to 1 Gsps. The SEU cross-section has been measured as a function of sample rate for various input levels. The data collected is clearly non-linear for all cases. The data shows that this device has a relative low cross-section for proton-induced SEUs and remains functional at a proton dose of 580 krad (Si). (A.C.)

  5. Nuclear data relevant to single-event upsets (SEU) in microelectronics and their application to SEU simulation

    International Nuclear Information System (INIS)

    Watanabe, Yukinobu; Tukamoto, Yasuyuki; Kodama, Akihiro; Nakashima, Hideki

    2004-01-01

    A cross-section database for neutron-induced reactions on 28 Si was developed in the energy range between 2 MeV and 3 GeV in order to analyze single-event upsets (SEUs) phenomena induced by cosmic-ray neutrons in microelectronic devices. A simplified spherical device model was proposed for simulation of the initial process of SEUs. The model was applied to SEU cross-section calculations for semiconductor memory devices. The calculated results were compared with measured SEU cross-sections and the other simulation result. The dependence of SEU cross-sections on incident neutron energy and secondary ions having the most important effects on SEUs are discussed. (author)

  6. Experimental and 2D simulation study of the single-event burnout in n-channel power MOSFETs

    International Nuclear Information System (INIS)

    Roubaud, F.; Dachs, C.; Palau, J.M.; Gasiot, J.

    1993-01-01

    The use of the 2D simulator MEDICI as a tool for Single Event Burnout (SEB) comprehension is investigated. Simulation results are compared to experimental currents induced in an N channel power MOSFET by the ions from a 252 Cf source. Current measurements have been carried out with a specially designed circuit. Simulations allow to analyze separately the effects of the ion impact and of the electrical environment parameters on the SEB phenomenon. Burnout sensitivity is found to be increased by increasing supply voltage, ion's LET and by decreasing load charge. These electrical tendencies are validated by experiments. Burnout sensitivity is also found to be sensitive to the ion impact position. The current shapes variations for given electrical parameters can be related to LET or ion impact position changes. However, some experimental current shapes are not reproduced by simulations

  7. Solid state detector for high spatial resolution coupled to a single event acquisition system for slow neutron detection

    Science.gov (United States)

    Casinini, F.; Petrillo, C.; Sacchetti, F.

    2012-05-01

    In the next years the slow neutron scattering community is waiting for a continuous improvement of the neutron detectors because of the development of the new and more intense neutron sources and to obtain a better performance of the neutron instrumentation to face the higher demands and new capabilities necessary for the novel experiments. In particular detectors having a faster response and a better shape of the time response must be produced, while new and more flexible acquisition systems must be introduced in order to collect in the proper way the information carried by the scattered neutrons. At present inside the neutron detector community the lack for detectors having a spatial resolution below 1 mm is evident. In the past it has been already demonstrated that a silicon microstrip detector coupled to a Gadolinium foil, used as neutron converter, provides a good performance neutron detector. In the present paper we present a 128 channel detector which has been designed for operation in the thermal neutron region with 0.55 mm spatial resolution, 100 ns time resolution and 25 ns time stamp accuracy. We present a new approach for the acquisition of the neutron arrival time, based on a single event storage by manipulating the detector digital output using a programmable acquisition system which takes advantage from high performance industrial standard hardware employing a FPGA and a real-time on board processor. We suggest the use of the single neutron event storing to make the time to energy transformation more efficient in the case of time of flight inelastic scattering, where the conversion from angle and time to momentum and energy is necessary.

  8. Absolute Quantification of Rifampicin by MALDI Imaging Mass Spectrometry Using Multiple TOF/TOF Events in a Single Laser Shot.

    Science.gov (United States)

    Prentice, Boone M; Chumbley, Chad W; Caprioli, Richard M

    2017-01-01

    Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for the visualization of molecular distributions within tissue sections. While providing excellent molecular specificity and spatial information, absolute quantification by MALDI IMS remains challenging. Especially in the low molecular weight region of the spectrum, analysis is complicated by matrix interferences and ionization suppression. Though tandem mass spectrometry (MS/MS) can be used to ensure chemical specificity and improve sensitivity by eliminating chemical noise, typical MALDI MS/MS modalities only scan for a single MS/MS event per laser shot. Herein, we describe TOF/TOF instrumentation that enables multiple fragmentation events to be performed in a single laser shot, allowing the intensity of the analyte to be referenced to the intensity of the internal standard in each laser shot while maintaining the benefits of MS/MS. This approach is illustrated by the quantitative analyses of rifampicin (RIF), an antibiotic used to treat tuberculosis, in pooled human plasma using rifapentine (RPT) as an internal standard. The results show greater than 4-fold improvements in relative standard deviation as well as improved coefficients of determination (R 2 ) and accuracy (>93% quality controls, errors). This technology is used as an imaging modality to measure absolute RIF concentrations in liver tissue from an animal dosed in vivo. Each microspot in the quantitative image measures the local RIF concentration in the tissue section, providing absolute pixel-to-pixel quantification from different tissue microenvironments. The average concentration determined by IMS is in agreement with the concentration determined by HPLC-MS/MS, showing a percent difference of 10.6%. Graphical Abstract ᅟ.

  9. Study of Single Event Effects induced by highly energetic charged particles of the space environment in CMOS image Sensors

    International Nuclear Information System (INIS)

    Lalucaa, Valerian

    2013-01-01

    This thesis studies the single event effects of space environment in CMOS image sensors (CIS). This work focuses on the effects of heavy ions on 3T standard photodiode pixels, and 4T and 5T pinned photodiode pixels. The first part describes the space radioactive environment and the sensor architecture. The most harmful events (SEL and SETs) are identified thanks to the scientific literature. The experimentally tested sensors agree with the theoretical work. SETs are compared to STARDUST simulations with a good agreement for all ions and sensors. The work explains why the SETs on 3T pixels are insensitive to the various photodiode designs, and they are decreased when an epitaxial substrate is used. A method using anti-blooming was successfully used in 4T and 5T pixels to prevent the spread of the SETs. The mechanism of latch-up in 4T pixel sensors is described. All the identified mechanisms are very useful to provide hardening methods for the CISs. (author) [fr

  10. Precision Seismic Monitoring of Volcanic Eruptions at Axial Seamount

    Science.gov (United States)

    Waldhauser, F.; Wilcock, W. S. D.; Tolstoy, M.; Baillard, C.; Tan, Y. J.; Schaff, D. P.

    2017-12-01

    Seven permanent ocean bottom seismometers of the Ocean Observatories Initiative's real time cabled observatory at Axial Seamount off the coast of the western United States record seismic activity since 2014. The array captured the April 2015 eruption, shedding light on the detailed structure and dynamics of the volcano and the Juan de Fuca midocean ridge system (Wilcock et al., 2016). After a period of continuously increasing seismic activity primarily associated with the reactivation of caldera ring faults, and the subsequent seismic crisis on April 24, 2015 with 7000 recorded events that day, seismicity rates steadily declined and the array currently records an average of 5 events per day. Here we present results from ongoing efforts to automatically detect and precisely locate seismic events at Axial in real-time, providing the computational framework and fundamental data that will allow rapid characterization and analysis of spatio-temporal changes in seismogenic properties. We combine a kurtosis-based P- and S-phase onset picker and time domain cross-correlation detection and phase delay timing algorithms together with single-event and double-difference location methods to rapidly and precisely (tens of meters) compute the location and magnitudes of new events with respect to a 2-year long, high-resolution background catalog that includes nearly 100,000 events within a 5×5 km region. We extend the real-time double-difference location software DD-RT to efficiently handle the anticipated high-rate and high-density earthquake activity during future eruptions. The modular monitoring framework will allow real-time tracking of other seismic events such as tremors and sea-floor lava explosions that enable the timing and location of lava flows and thus guide response research cruises to the most interesting sites. Finally, rapid detection of eruption precursors and initiation will allow for adaptive sampling by the OOI instruments for optimal recording of future

  11. SEISMIC ANALYSIS FOR PRECLOSURE SAFETY

    International Nuclear Information System (INIS)

    E.N. Lindner

    2004-01-01

    The purpose of this seismic preclosure safety analysis is to identify the potential seismically-initiated event sequences associated with preclosure operations of the repository at Yucca Mountain and assign appropriate design bases to provide assurance of achieving the performance objectives specified in the Code of Federal Regulations (CFR) 10 CFR Part 63 for radiological consequences. This seismic preclosure safety analysis is performed in support of the License Application for the Yucca Mountain Project. In more detail, this analysis identifies the systems, structures, and components (SSCs) that are subject to seismic design bases. This analysis assigns one of two design basis ground motion (DBGM) levels, DBGM-1 or DBGM-2, to SSCs important to safety (ITS) that are credited in the prevention or mitigation of seismically-initiated event sequences. An application of seismic margins approach is also demonstrated for SSCs assigned to DBGM-2 by showing a high confidence of a low probability of failure at a higher ground acceleration value, termed a beyond-design basis ground motion (BDBGM) level. The objective of this analysis is to meet the performance requirements of 10 CFR 63.111(a) and 10 CFR 63.111(b) for offsite and worker doses. The results of this calculation are used as inputs to the following: (1) A classification analysis of SSCs ITS by identifying potential seismically-initiated failures (loss of safety function) that could lead to undesired consequences; (2) An assignment of either DBGM-1 or DBGM-2 to each SSC ITS credited in the prevention or mitigation of a seismically-initiated event sequence; and (3) A nuclear safety design basis report that will state the seismic design requirements that are credited in this analysis. The present analysis reflects the design information available as of October 2004 and is considered preliminary. The evolving design of the repository will be re-evaluated periodically to ensure that seismic hazards are properly

  12. SEISMIC ANALYSIS FOR PRECLOSURE SAFETY

    Energy Technology Data Exchange (ETDEWEB)

    E.N. Lindner

    2004-12-03

    The purpose of this seismic preclosure safety analysis is to identify the potential seismically-initiated event sequences associated with preclosure operations of the repository at Yucca Mountain and assign appropriate design bases to provide assurance of achieving the performance objectives specified in the Code of Federal Regulations (CFR) 10 CFR Part 63 for radiological consequences. This seismic preclosure safety analysis is performed in support of the License Application for the Yucca Mountain Project. In more detail, this analysis identifies the systems, structures, and components (SSCs) that are subject to seismic design bases. This analysis assigns one of two design basis ground motion (DBGM) levels, DBGM-1 or DBGM-2, to SSCs important to safety (ITS) that are credited in the prevention or mitigation of seismically-initiated event sequences. An application of seismic margins approach is also demonstrated for SSCs assigned to DBGM-2 by showing a high confidence of a low probability of failure at a higher ground acceleration value, termed a beyond-design basis ground motion (BDBGM) level. The objective of this analysis is to meet the performance requirements of 10 CFR 63.111(a) and 10 CFR 63.111(b) for offsite and worker doses. The results of this calculation are used as inputs to the following: (1) A classification analysis of SSCs ITS by identifying potential seismically-initiated failures (loss of safety function) that could lead to undesired consequences; (2) An assignment of either DBGM-1 or DBGM-2 to each SSC ITS credited in the prevention or mitigation of a seismically-initiated event sequence; and (3) A nuclear safety design basis report that will state the seismic design requirements that are credited in this analysis. The present analysis reflects the design information available as of October 2004 and is considered preliminary. The evolving design of the repository will be re-evaluated periodically to ensure that seismic hazards are properly

  13. Role of seismic PRA in seismic safety decisions of nuclear power plants

    International Nuclear Information System (INIS)

    Ravindra, M.K.; Kennedy, R.P.; Sues, R.H.

    1985-01-01

    This paper highlights the important roles that seismic probabilistic risk assessments (PRAs) can play in the seismic safety decisions of nuclear power plants. If a seismic PRA has been performed for a plant, its results can be utilized to evaluate the seismic capability beyond the safe shutdown event (SSE). Seismic fragilities of key structures and equipment, fragilities of dominant plant damage states and the frequencies of occurrence of these plant damage states are reviewed to establish the seismic safety of the plant beyond the SSE level. Guidelines for seismic margin reviews and upgrading may be developed by first identifying the generic classes of structures and equipment that have been shown to be dominant risk contributors in the completed seismic PRAs, studying the underlying causes for their contribution and examining why certain other items (e.g., piping) have not proved to be high-risk-contributors

  14. Addressing concerns related to geologic hazards at the site of the proposed Transuranic Waste Facility , TA-63, Los Alamos National Laboratory: focus on the current Los Alamos Seismic Network earthquake catalog, proximity of identified seismic events to the proposed facility , and evaluation of prev

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Peter M. [Los Alamos National Laboratory; Schultz-Fellenz, Emily S. [Los Alamos National Laboratory; Kelley, Richard E. [Los Alamos National Laboratory

    2012-04-02

    . Understanding the subtle differences between Tshirege Member cooling units and the nature of the contacts between cooling units is critical to identifying the presence or absence of faults associated with the Pajarito fault system on the Pajarito Plateau. The Los Alamos Seismic Network (LASN) continuously monitors local earthquake activity in the Los Alamos area in support of LANL's Seismic Hazards program. Seismic monitoring of LANL facilities is a requirement of DOE Order 420.1B (Facility Safety). LASN currently consists of nine permanent seismic instrument field stations that telemeter real-time sensitive ground motion data to a central recording facility. Four of these stations are located on LANL property, with three of those within 2.5 miles of TA-63. The other five stations are in remote locations in the Jemez Mountains, Valles Caldera, St Peters Dome, and the Caja del Rio plateau across the Rio Grande from the Los Alamos area. Local earthquakes are defined as those with locations within roughly 100 miles of Los Alamos. Plate 1 shows the current LASN station locations and all local earthquakes recorded from 1973 through 2011. During this time period, LASN has detected and recorded over 850 local earthquakes in north-central New Mexico. Over 650 of these were located within about 50 miles of Los Alamos, and roughly 60 were within 10 miles. The apparent higher density of earthquakes close to Los Alamos, relative to the rest of north-central New Mexico, is due largely to the fact that LASN is a sensitive local seismic network, recording many very small nearby events (magnitude less than 1.0) that are undetectable at greater distances.

  15. Sequencing of Single Pollen Nuclei Reveals Meiotic Recombination Events at Megabase Resolution and Circumvents Segregation Distortion Caused by Postmeiotic Processes

    Directory of Open Access Journals (Sweden)

    Steven Dreissig

    2017-09-01

    Full Text Available Meiotic recombination is a fundamental mechanism to generate novel allelic combinations which can be harnessed by breeders to achieve crop improvement. The recombination landscape of many crop species, including the major crop barley, is characterized by a dearth of recombination in 65% of the genome. In addition, segregation distortion caused by selection on genetically linked loci is a frequent and undesirable phenomenon in double haploid populations which hampers genetic mapping and breeding. Here, we present an approach to directly investigate recombination at the DNA sequence level by combining flow-sorting of haploid pollen nuclei of barley with single-cell genome sequencing. We confirm the skewed distribution of recombination events toward distal chromosomal regions at megabase resolution and show that segregation distortion is almost absent if directly measured in pollen. Furthermore, we show a bimodal distribution of inter-crossover distances, which supports the existence of two classes of crossovers which are sensitive or less sensitive to physical interference. We conclude that single pollen nuclei sequencing is an approach capable of revealing recombination patterns in the absence of segregation distortion.

  16. Causality between expansion of seismic cloud and maximum magnitude of induced seismicity in geothermal field

    Science.gov (United States)

    Mukuhira, Yusuke; Asanuma, Hiroshi; Ito, Takatoshi; Häring, Markus

    2016-04-01

    Occurrence of induced seismicity with large magnitude is critical environmental issues associated with fluid injection for shale gas/oil extraction, waste water disposal, carbon capture and storage, and engineered geothermal systems (EGS). Studies for prediction of the hazardous seismicity and risk assessment of induced seismicity has been activated recently. Many of these studies are based on the seismological statistics and these models use the information of the occurrence time and event magnitude. We have originally developed physics based model named "possible seismic moment model" to evaluate seismic activity and assess seismic moment which can be ready to release. This model is totally based on microseismic information of occurrence time, hypocenter location and magnitude (seismic moment). This model assumes existence of representative parameter having physical meaning that release-able seismic moment per rock volume (seismic moment density) at given field. Seismic moment density is to be estimated from microseismic distribution and their seismic moment. In addition to this, stimulated rock volume is also inferred by progress of microseismic cloud at given time and this quantity can be interpreted as the rock volume which can release seismic energy due to weakening effect of normal stress by injected fluid. Product of these two parameters (equation (1)) provide possible seismic moment which can be released from current stimulated zone as a model output. Difference between output of this model and observed cumulative seismic moment corresponds the seismic moment which will be released in future, based on current stimulation conditions. This value can be translated into possible maximum magnitude of induced seismicity in future. As this way, possible seismic moment can be used to have feedback to hydraulic stimulation operation in real time as an index which can be interpreted easily and intuitively. Possible seismic moment is defined as equation (1), where D

  17. Use of the t-Distribution to Construct Seismic Hazard Curves for Seismic Probabilistic Safety Assessments

    Directory of Open Access Journals (Sweden)

    Eric Yee

    2017-03-01

    Full Text Available Seismic probabilistic safety assessments are used to help understand the impact potential seismic events can have on the operation of a nuclear power plant. An important component to seismic probabilistic safety assessment is the seismic hazard curve which shows the frequency of seismic events. However, these hazard curves are estimated assuming a normal distribution of the seismic events. This may not be a strong assumption given the number of recorded events at each source-to-site distance. The use of a normal distribution makes the calculations significantly easier but may underestimate or overestimate the more rare events, which is of concern to nuclear power plants. This paper shows a preliminary exploration into the effect of using a distribution that perhaps more represents the distribution of events, such as the t-distribution to describe data. The integration of a probability distribution with potentially larger tails basically pushes the hazard curves outward, suggesting a different range of frequencies for use in seismic probabilistic safety assessments. Therefore the use of a more realistic distribution results in an increase in the frequency calculations suggesting rare events are less rare than thought in terms of seismic probabilistic safety assessment. However, the opposite was observed with the ground motion prediction equation considered.

  18. Improvements on the seismic catalog previous to the 2011 El Hierro eruption.

    Science.gov (United States)

    Domínguez Cerdeña, Itahiza; del Fresno, Carmen

    2017-04-01

    Precursors from the submarine eruption of El Hierro (Canary Islands) in 2011 included 10,000 low magnitude earthquakes and 5 cm crustal deformation within 81 days previous to the eruption onset on the 10th October. Seismicity revealed a 20 km horizontal migration from the North to the South of the island and depths ranging from 10 and 17 km with deeper events occurring further South. The earthquakes of the seismic catalog were manually picked by the IGN almost in real time, but there has not been a subsequent revision to check for new non located events jet and the completeness magnitude for the seismic catalog have strong changes during the entire swarm due to the variable number of events per day. In this work we used different techniques to improve the quality of the seismic catalog. First we applied different automatic algorithms to detect new events including the LTA-STA method. Then, we performed a semiautomatic system to correlate the new P and S detections with known phases from the original catalog. The new detected earthquakes were also located using Hypoellipse algorithm. The resulting new catalog included 15,000 new events mainly concentrated in the last weeks of the swarm and we assure a completeness magnitude of 1.2 during the whole series. As the seismicity from the original catalog was already relocated using hypoDD algorithm, we improved the location of the new events using a master-cluster relocation. This method consists in relocating earthquakes towards a cluster of well located events instead of a single event as the master-event method. In our case this cluster correspond to the relocated earthquakes from the original catalog. Finally, we obtained a new equation for the local magnitude estimation which allow us to include corrections for each seismic station in order to avoid local effects. The resulting magnitude catalog has a better fit with the moment magnitude catalog obtained for the strong earthquakes of this series in previous studies

  19. Are seismic hazard assessment errors and earthquake surprises unavoidable?

    Science.gov (United States)

    Kossobokov, Vladimir

    2013-04-01

    Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess seismic hazard. The time-span of physically reliable Seismic History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized seismic hazard. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. Seismic events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground acceleration estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE SEISMIC RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global seismic hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a

  20. Seismic protection

    International Nuclear Information System (INIS)

    Herbert, R.

    1988-01-01

    To ensure that a nuclear reactor or other damage-susceptible installation is, so far as possible, tripped and already shut down before the arrival of an earthquake shock at its location, a ring of monitoring seismic sensors is provided around it, each sensor being spaced from it by a distance (possibly several kilometres) such that (taking into account the seismic-shock propagation velocity through the intervening ground) a shock monitored by the sensor and then advancing to the installation site will arrive there later than a warning signal emitted by the sensor and received at the installation, by an interval sufficient to allow the installation to trip and shut down, or otherwise assume an optimum anti-seismic mode, in response to the warning signal. Extra sensors located in boreholes may define effectively a three-dimensional (hemispherical) sensing boundary rather than a mere two-dimensional ring. (author)

  1. Seismic Studies

    Energy Technology Data Exchange (ETDEWEB)

    R. Quittmeyer

    2006-09-25

    This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

  2. Stutter seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Gumma, W. H.; Hughes, D. R.; Zimmerman, N. S.

    1980-08-12

    An improved seismic prospecting system comprising the use of a closely spaced sequence of source initiations at essentially the same location to provide shorter objective-level wavelets than are obtainable with a single pulse. In a preferred form, three dynamite charges are detonated in the same or three closely spaced shot holes to generate a downward traveling wavelet having increased high frequency content and reduced content at a peak frequency determined by initial testing.

  3. Convolutional Neural Networks for Earthquake Detection and Location of Seismicity in Central Oklahoma

    Science.gov (United States)

    Perol, T.; Gharbi, M.; Denolle, M.

    2016-12-01

    Induced seismicity is characterized by localized activity of small-scale and moderate-magnitude earthquakes. Poor instrumental coverage limits the accuracy of traditional techniques for earthquake detection and localization. Currently, the most effective approach to detect new (and smaller) events is the so-called template matching method. It matches events' waveforms against previously-seen waveform templates. This restricts the search to events that are collocated with the cataloged events. We propose an alternative method, which we called ConvNetQuake, that leverages recent advances in convolutional neural networks for pattern recognition and classification. Once trained on a dataset of 3-component seismograms, ConvNetQuake learns a bank of finite impulse response filters that can discriminate seismic events against noise. First, we compare our algorithm to template matching on synthetic data. We generate synthetic waveforms by adding randomly scaled copies of a single 3-component template at random temporal offsets over a Gaussian noise floor. While the accuracy of ConvNetQuake is slightly lower than that of template matching, it has the advantage of a more compact non-linear representation that can detect new events that were not in the training set. Second, we cluster the Guthrie earthquakes using a Multivariate Gaussian Mixture Model (MGMM) based on the Oklahoma Geological Survey (OGS) catalog and sample a few events from each cluster. We proceed as before and construct synthetic seismograms with the additional information of the events' location. We now train our algorithm to discriminate events from the noise and, jointly, to estimate the probability than the event belongs to a particular cluster. Using the MGMM, we produce maps of the continuous probability distribution of event location. Finally, we apply ConvNetQuake to the Guthrie sequence by training it on data from February 15th, 2014 to August, 31th 2014 using the known cataloged seismicity provided

  4. From Initial Models of Seismicity, Structure and Noise to Synthetic Seismograms for Mars

    Science.gov (United States)

    Ceylan, Savas; van Driel, Martin; Euchner, Fabian; Khan, Amir; Clinton, John; Krischer, Lion; Böse, Maren; Stähler, Simon; Giardini, Domenico

    2017-10-01

    The InSight mission will land a single seismic station on Mars in November 2018, and the resultant seismicity catalog will be a key component for studies aiming to understand the interior structure of the planet. Here, we present a preliminary version of the web services that will be used to distribute the event and station metadata in practice, employing synthetic seismograms generated for Mars using a catalog of expected seismicity. Our seismicity catalog consists of 120 events with double-couple source mechanisms only. We also provide Green's functions databases for a total of 16 structural models, which are constructed to reflect one-dimensional thin (30 km) and thick (80 km) Martian crust with varying seismic wave speeds and densities, combined with two different profiles for temperature and composition for the mantle. Both the Green's functions databases and the precomputed seismograms are accessible online. These new utilities allow the researchers to either download the precomputed synthetic waveforms directly, or produce customized data sets using any desired source mechanism and event distribution via our servers.

  5. Pick- and waveform-based techniques for real-time detection of induced seismicity

    Science.gov (United States)

    Grigoli, Francesco; Scarabello, Luca; Böse, Maren; Weber, Bernd; Wiemer, Stefan; Clinton, John F.

    2018-01-01

    The monitoring of induced seismicity is a common operation in many industrial activities, such as conventional and non-conventional hydrocarbon production or mining and geothermal energy exploitation, to cite a few. During such operations we generally collect very large and strongly noise-contaminated datasets that require robust and automated analysis procedures. Induced seismicity datasets are often characterized by sequences of multiple events with short inter-event times or overlapping events; in these cases, pick-based location methods may struggle to correctly assign picks to phases and events, and errors can lead to missed detections and/or reduced location resolution and incorrect magnitudes, which can have significant consequences if real-time seismicity information are used for risk assessment frameworks. To overcome these issues, different waveform-based methods for the detection and location of microseismicity have been proposed. The main advantages of waveform based methods is that they appear to perform better and can simultaneously detect and locate seismic events providing high quality locations in a single step, while the main disadvantage is that they are computationally expensive. Although these methods have been applied to different induced seismicity datasets, an extensive comparison with sophisticated pick-based detection methods is still missing. In this work we introduce our improved waveform-based detector and we compare its performance with two pick-based detectors implemented within the SeiscomP3 software suite. We test the performance of these three approaches with both synthetic and real datasets related to the induced seismicity sequence at the deep geothermal project in the vicinity of the city of St. Gallen, Switzerland.

  6. Seismic Symphonies

    Science.gov (United States)

    Strinna, Elisa; Ferrari, Graziano

    2015-04-01

    The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of seismic records. In this case seismic frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation system that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the seismic records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's Seismic Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of seismic history of the Earth. A bridge between art and science. Seismic Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and

  7. Discrimination of Earthquake and Blast Seismicity in Western Alberta

    Science.gov (United States)

    Spriggs, N.; Law, A.; Yenier, E.; Reynen, A.; Baturan, D.

    2015-12-01

    Recorded seismicity in western Alberta is caused by natural and induced earthquakes or blast events from mining and quarry operations. Accurate discrimination of earthquakes from blast events is crucial for evaluating recent seismicity with respect to the historical catalog and for assessing seismic hazards associated with naturally occurring or induced seismicity. In general, blast events are discriminated from earthquakes based on their proximity to active mines and quarries in addition to day-of-week and time-of-day timing patterns. In some parts of western Alberta, however, seismicity originates in regions with active mines, historical earthquake seismicity, and hydraulic fracturing operations. Based on timing patterns or event locations alone, natural or induced seismicity may be misidentified as mining activity. Several studies report that relative differences in Fourier or response spectra can be used to discriminate blast and earthquake events. Other studies report that the relative timing and amplitude of seismic phases may provide useful metrics for classifying blast events. Here we propose an alternative method that accounts for both differences in phase spectra and phase timing and amplitude. In particular, we evaluate the normalized time integral for characteristic functions of particle motion from confirmed blast and earthquake events recorded by regional Alberta seismic networks. We then use these time-integral profiles to re-classify events that are initially categorized as suspected blasts based on timing pattern and event location indicators.

  8. Effect of body biasing on single-event induced charge collection in deep N-well technology

    International Nuclear Information System (INIS)

    Ding Yi; Hu Jian-Guo; Tan Hong-Zhou; Qin Jun-Rui

    2015-01-01

    As the device size decreases, the soft error induced by space ions is becoming a great concern for the reliability of integrated circuits (ICs). At present, the body biasing technique is widely used in highly scaled technologies. In the paper, using the three-dimensional technology computer-aided design (TCAD) simulation, we analyze the effect of the body biasing on the single-event charge collection in deep N-well technology. Our simulation results show that the body biasing mainly affects the behavior of the source, and the effect of body biasing on the charge collection for the nMOSFET and pMOSFET is quite different. For the nMOSFET, the RBB will increase the charge collection, while the FBB will reduce the charge collection. For the pMOSFET, the effect of RBB on the SET pulse width is small, while the FBB has an adverse effect. Moreover, the differenceof the effect of body biasing on the charge collection is compared in deep N-well and twin well. (paper)

  9. 1D layered velocity models and microseismic event locations: synthetic examples for a case with a single linear receiver array

    Science.gov (United States)

    Akram, Jubran; Eaton, David W.

    2017-10-01

    We discuss various aspects of 1D velocity-model building for application to microseismic data analysis. We generate simple synthetic example data using a widely used single linear array geometry. The synthetic data contain 30 sources with known locations for a reference model based on previous studies of the Barnett shale. We investigate several key factors that should be considered, including selection of the calibration technique, inclusion of a priori information such as lateral heterogeneity and parameter ranges, and choice of algorithm for travel time computations. For the source-receiver geometry considered here, hypocenter location errors (±6 m in X and ±12 m in Z) can result from differently calibrated models only and without including the errors in picked arrival times and polarization estimates. We find that the errors in hypocenter locations are reduced (±3 m in X and ±6 m in Z) when a model calibrated with multiple shots simultaneously is used. Using four different models (vertical fault, dipping layers, channels, and these effects combined), we demonstrate that systematic errors in hypocenter locations can result when a 1D layered model is used in lieu of a laterally heterogeneous subsurface. Finally, we show that event locations from a velocity model calibrated using direct-arrival times are more stable than from a model calibrated with first-arrival times.

  10. Theoretical and experimental studies of single event effect induced by atmospheric muons on nano-metric technologies

    International Nuclear Information System (INIS)

    Li Cavoli, P.

    2016-01-01

    This study concerns the domain of the microelectronics. It consists in the study of the impact of the 3D morphology of the energy deposit on the Single Event Effect (SEE) modeling, induced by atmospheric muons. Over a first phase, the approach has consisted in the modeling of the energy deposit induced by protons in nano-metric volumes. For that purpose the use of the Monte Carlo code GEANT4 has allowed us to simulate and stock in a database the tracks characteristics of the energy deposit induced by protons. Once the approach validated for the protons, simulations of the energy deposit induced by muons have been realized. A CCD camera has been used in order to measure the radiative atmospheric environment and to constrain the modeling of the energy deposit induced by muons. This study highlights and quantify the contribution of the radial distribution of the energy deposit induced by protons in nano-metric volumes for the SEE prediction. On the other hand, the study shows that the contribution of the radial distribution of the energy deposit induced by muons in nano-metric volumes has a negligible impact on the SEE modeling. It will be interesting to realize measurements of the energy deposit induced by muons in nano-metric technologies under particle accelerator. This will allow to bring experimental data still nonexistent necessary to the development of new physical models more accurate on the modeling of the energy deposit induced by muons. (author)

  11. Contextual constraints on lexico-semantic processing in aging: Evidence from single-word event-related brain potentials.

    Science.gov (United States)

    Payne, Brennan R; Federmeier, Kara D

    2018-05-15

    The current study reports the effects of accumulating contextual constraints on neural indices of lexico-semantic processing (i.e., effects of word frequency and orthographic neighborhood) as a function of normal aging. Event-related brain potentials were measured from a sample of older adults as they read sentences that were semantically congruent, provided only syntactic constraints (syntactic prose), or were random word strings. A linear mixed-effects modeling approach was used to probe the effects of accumulating contextual constraints on N400 responses to individual words. Like young adults in prior work, older adults exhibited a classic word position context effect on the N400 in congruent sentences, although the magnitude of the effect was reduced in older relative to younger adults. Moreover, by modeling single-word variability in N400 responses, we observed robust effects of orthographic neighborhood density that were larger in older adults than the young, and preserved effects word frequency. Importantly, in older adults, frequency effects were not modulated by accumulating contextual constraints, unlike in the young. Collectively, these findings indicate that older adults are less likely (or able) to use accumulating top-down contextual constraints, and therefore rely more strongly on bottom-up lexical features to guide semantic access of individual words during sentence comprehension. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. An optical fiber coupled streak camera system for multichannel recording of simultaneous emission from a single plasma producing event

    International Nuclear Information System (INIS)

    Tan, T.H.; Williams, A.H.

    1983-01-01

    A streak camera system capable of multichannel sub-nanosecond recording of simultaneous emissions (photons and particles) from a single plasma interaction event (laser or particle beam) has been developed. In this system ultra-fast quenched (benzophenone) plastic scintillator detectors are coupled via optical fibers to a visible streak camera. The use of optical fibers presents two tractive features: miniaturization of detectors permits improved flexibility in placing detectors at the most desirable location and in greater number than can normally be accommodated; and the detectors are insensitive to electromagnetic noise generated both from the interacting plasmas and from the high voltage components associated with the laser or particle beam system. The fibers can be directly routed through vacuum tight couplers at the target chamber wall and brought into direct contact with the photocathode of the camera in most applications. In fusion experiments, however, the fiber florescence and Cerenkov radiation due to the copious emissions of energetic electrons and x-rays can present serious problems in the use of long fibers. Here, short fibers can be used and the visible streak camera is then focused through a glass port of the target chamber onto the open ends of these optical fibers

  13. Local seismicity in the area of Tornio River (northern Fennoscandia) revealed by analysis of local events registered by the POLENET/LAPNET array

    Science.gov (United States)

    Kozlovskaya, E.; Usoltseva, O.; Konstantinovskaya, N.

    2012-04-01

    The region of Tornio river (22-26 deg E and 66.5-69 deg N) is very interesting for seismological studies because it is crossed by systems of tectonic faults spreading in two different directions. 56 local earthquakes originated from this region were recorded by the POLENET/LAPNET temporary array from May, 2007 to May, 2009. Hypocenter depths of earthquakes are in the range of 1-35 km and their magnitudes vary from 0.8 to 2.2. For events detection we used the bulletin of the Institute of Seismology (Helsinki university) and Norway Global Beam Forming bulletin, compiled on the base of automatic detection of events, using the data of Noress, Arcess, Finess, SPA, HFS, APA arrays. In addition to local earthquakes, the array recorded 364 blasts from this region during the POLENET/LAPNET observation period. The events were relocated using manually measured travel times of refracted P waves from events at local distances (less than 200 km) and the 1-D velocity model along the wide-angle reflection and refraction HUKKA profile. The epicenters of relocated events show good correlation with known faults in the region. For each earthquake we constructed travel-time curves with reduction velocity of 8 km/s and compared them with the theoretical travel-time curves, in order to avoid phase misinterpretation. We found out that the largest reduction of travel time residuals during relocation was reached for deep earthquakes, due to more precise depth determination. The other aim of our study was to estimate what part of travel time residuals is not connected with the reference 1D velocity model and accuracy of location, but is rather due to 3-D heterogeneities in the crust. We also analyzed the amplitude characteristics of P-wave arrivals from different layers in the crust and upper mantle and also compared spectrograms of deep earthquakes, shallow earthquakes and blasts.

  14. A systematic review of the association between a single strenuous event and the development of an inguinal hernia: A medicolegal grey area.

    Science.gov (United States)

    Patterson, Timothy; Currie, Peter; Spence, Robert; McNally, Sinead; Spence, Gary

    2018-03-10

    Inguinal hernia is a common surgical presentation. Evidence for its causation regarding occupational and recreational physical exposures is limited. The aim of this study is to conduct a systematic review objectively evaluating the evidence for a causal link between a single strenuous event and the development of an inguinal hernia. A systematic review was carried out in accordance with PRISMA guidelines. PubMed, Ovid Embase, SCOPUS, and Cochrane Library were searched. In addition, the ISRCTN register, ClinicalTrials.gov, ICTR Platform, and EU Clinical Trials Register were searched. Identified publications were collated and both reviewers independently reviewed their contents. 5508 records were identified, resulting in 5 studies being selected. These 5 studies were all case series. Of 957 patients identified, 1003 hernias were described, of which 983 were inguinal hernias which 255 (26%) were attributed by patients to a single strenuous event. Only two of these studies applied Smith's Criteria (causation of a hernia from a single strenuous event): officially reported, severe pain at the time of the event, no prior history of inguinal hernia, and the diagnosis was made by a doctor within 30 days (preferably 3 days). Only 2 of 54 patients (4%) met all four criteria and so could be considered as having an inguinal hernia relating to a single strenuous event. Many patients associate hernias to a single episode, however upon application of more stringent criteria such as Smith's, a much smaller proportion are deemed to be actually attributable to a single strenuous event. Copyright © 2018 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  15. SEISMIC DESIGN OF TWO STOREY REINFORCED CONCRETE BUILDING IN MALAYSIA WITH LOW CLASS DUCTILITY

    Directory of Open Access Journals (Sweden)

    MOHD IRWAN ADIYANTO

    2014-02-01

    Full Text Available Since Malaysia is not located in active seismic fault zones, majority of buildings in Malaysia had been designed according to BS8110, which not specify any seismic provision. After experienced several tremors originating from neighbouring countries especially from Sumatra, Indonesia, the Malaysian start to ask questions on integrity of existing structures in Malaysia to withstand the earthquake load. The question also arises regarding the economical effect in term of cost of construction if seismic design has to be implemented in Malaysian construction industry. If the cost is increasing, how much the increment and is it affordable? This paper investigated the difference of steel reinforcement and concrete volume required when seismic provision is considered in reinforced concrete design of 2 storey general office building. The regular office building which designed based on BS8110 had been redesigned according to Eurocode 2 with various level of reference peak ground acceleration, agR reflecting Malaysian seismic hazard for ductility class low. Then, the all frames had been evaluated using a total of 800 nonlinear time history analyses considering single and repeated earthquakes to simulate the real earthquake event. It is observed that the level of reference peak ground acceleration, agR and behaviour factor, q strongly influence the increment of total cost. For 2 storey RC buildings built on Soil Type D with seismic consideration, the total cost of material is expected to increase around 6 to 270%, depend on seismic region. In term of seismic performance, the repeated earthquake tends to cause increasing in interstorey drift ratio around 8 to 29% higher compared to single earthquake.

  16. The Impact of Electronic Medical Records on Hospital-Acquired Adverse Safety Events: Differential Effects Between Single-Source and Multiple-Source Systems.

    Science.gov (United States)

    Bae, Jaeyong; Rask, Kimberly J; Becker, Edmund R

    The objective was to examine differential impacts between single-source and multiple-source electronic medical record (EMR) systems, as measured by number of vendor products, on hospital-acquired patient safety events. The data source was the 2009-2010 State Inpatient Databases of the Healthcare Cost and Utilization Project for California, New York, and Florida, and the Information Technology Supplement to the American Hospital Association's Annual Survey. Multivariable regression analyses were conducted to estimate the differential impacts of EMRs between single-source and multiple-source EMR systems on hospital-acquired patient safety events. In all, 1.98% of adult surgery hospitalizations had at least 1 hospital-acquired patient safety event. Basic EMRs with a single vendor or self-developed EMR systems were associated with a significant decrease in patient safety events by 0.38 percentage point, or 19.2%, whereas basic EMRs with multiple vendors had an insignificant association. A single-source EMR system enhances the impact of EMRs on reducing patient safety events.

  17. Test Standard Revision Update: JESD57, "Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation"

    Science.gov (United States)

    Lauenstein, Jean-Marie

    2015-01-01

    The JEDEC JESD57 test standard, Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation, is undergoing its first revision since 1996. In this talk, we place this test standard into context with other relevant radiation test standards to show its importance for single-event effect radiation testing for space applications. We show the range of industry, government, and end-user party involvement in the revision. Finally, we highlight some of the key changes being made and discuss the trade-space in which setting standards must be made to be both useful and broadly adopted.

  18. Recent Vs. Historical Seismicity Analysis For Banat Seismic Region (Western Part Of Romania

    Directory of Open Access Journals (Sweden)

    Oros Eugen

    2015-03-01

    Full Text Available The present day seismic activity from a region reflects the active tectonics and can confirm the seismic potential of the seismogenic sources as they are modelled using the historical seismicity. This paper makes a comparative analysis of the last decade seismicity recorded in the Banat Seismic Region (western part of Romania and the historical seismicity of the region (Mw≥4.0. Four significant earthquake sequences have been recently localized in the region, three of them nearby the city of Timisoara (January 2012 and March 2013 and the fourth within Hateg Basin, South Carpathians (October 2013. These sequences occurred within the epicentral areas of some strong historical earthquakes (Mw≥5.0. The main events had some macroseismic effects on people up to some few kilometers from the epicenters. Our results update the Romanian earthquakes catalogue and bring new information along the local seismic hazard sources models and seismotectonics.

  19. Seismic probabilistic risk assessment and seismic-margins studies for nuclear power plants. Technical report

    International Nuclear Information System (INIS)

    Hwang, H.H.M.

    1987-01-01

    This report presents a review of the seismic probabilistic risk assessment and seismic margins studies for nuclear power plants in the United States. The techniques employed in these studies are briefly described. A few comments on the evaluation of the fragility of structures and equipment are discussed. Seismic PRA is a systematic process to evaluate the safety of nuclear power plants. In the process, it integrates all the elements such as seismic hazard, component fragility and plant system. Thus, it provides the overall view of the safety of an entire plant under a seismic event. The major tasks of a seismic PRA such as the evaluation of hazard curves, component fragilities. The concept and technique embodied in seismic PRA for nuclear power plants can be applied to other types of engineering facilities

  20. Seismic Signals of the 2014 Landslide near Oso, Washington

    Science.gov (United States)

    Allstadt, K.; Moran, S. C.; Malone, S. D.; Iverson, R. M.; George, D. L.

    2014-12-01

    The 22 March 2014 landslide near Oso, Washington rapidly moved a large volume of material (~8 million m^3), resulting in the efficient generation of seismic waves that were recorded over 350 km away. Analysis of these seismic signals significantly improves our understanding of the dynamics and timing of events. In contrast to the double couple mechanism of earthquakes, at long periods, the equivalent mechanism of a landslide is a single force. Inversion of the long-period waves for the forces exerted on the earth by the landslide yields a time-series that peaks at nearly 10^10 N and lasts ~1.5 minutes. This result, when combined with higher-frequency wave analysis, eyewitness reports, and field observations, implies a complex failure sequence. The earliest force pulses begin before the buildup in high-frequency energy, suggesting the slide began coherently before transitioning within a minute into the highly disrupted and destructive debris-avalanche flow that killed 43 people. This transition may have been due to a collapse of additional material that loaded the material downslope. Seismically observable "aftershock" landslides continued for weeks. The first and largest occurred a few minutes after the main failure sequence, and was followed by 15 more over the next ~4 hours that were observable at the closest seismic station (11 km away). Three USGS "spiders" equipped with GPS and seismic sensors were deployed by helicopter 10 days later as part of a monitoring effort. Due to their proximity, these seismometers detected signals from even minor collapses, some visually identified by human observers. This augmented network revealed interesting temporal patterns in the post-slide activity, which was dominated by sloughing of material from the headscarp, but also creep of the upper block of the failure mass at a rate of about 1 cm/day. This study shows the value of seismic analysis in landslide investigations to provide timing constraints and help improve our

  1. Seismic qualification of the primary loop of the non-seismically designed Belgian NPP

    International Nuclear Information System (INIS)

    Detroux, P.; Van Vyve, J.

    1989-01-01

    This paper describes the non linear time history analysis performed to seismically qualify the primary loop of the three first Belgian PWR plants. These plants (Chooz A 300 MWe - commissioned in 1966, and Doel 1/2 2 x 390 MWe - commissioned in 1974 and 1975) were not seismically designed, no seismic event being specified at that time. But, after respectively 20 years and 10 years of operation, the safety authorities required to seismically qualify the primary loop of these plants, for a SSE event. Both primary loops and, particularly, the Chooz A primary loop, have a supporting system that differs from the other seismically qualified Belgian NPP. A seismic qualification by analogy was thus not possible, but they are equipped with restraints designed for LOCA/SLB that will certainly be active in case of an SSE

  2. Post-seismic relaxation from geodetic and seismic data

    Directory of Open Access Journals (Sweden)

    Mikhail V. Rodkin

    2017-01-01

    Full Text Available We have examined the aftershock sequence and the post-seismic deformation process of the Parkfield earthquake (2004, M = 6, California, USA source area using GPS data. This event was chosen because of the possibility of joint analysis of data from the rather dense local GPS network (from SOPAC Internet archive and of the availability of the rather detailed aftershock sequence data (http://www.ncedc.org/ncedc/catalog-search.html. The relaxation process of post-seismic deformation prolongs about the same 400 days as the seismic aftershock process does. Thus, the aftershock process and the relaxation process in deformation could be the different sides of the same process. It should be noted that the ratio of the released seismic energy and of the GPS obtained deformation is quite different for the main shock and for the aftershock stage. The ratio of the released seismic energy to the deformation value decreases essentially for the post-shock process. The similar change in the seismic energy/deformation value ratio is valid in a few other strong earthquakes. Thus, this decrease seems typical of aftershock sequences testifying for decrease of ratio of elastic to inelastic deformation in the process of post-shock relaxation when the source area appears to be mostly fractured after the main shock occurs, but the healing process had no yet sufficient time to develop.

  3. Seismic Isolation Working Meeting Gap Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sabharwall, Piyush [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    The ultimate goal in nuclear facility and nuclear power plant operations is operating safety during normal operations and maintaining core cooling capabilities during off-normal events including external hazards. Understanding the impact external hazards, such as flooding and earthquakes, have on nuclear facilities and NPPs is critical to deciding how to manage these hazards to expectable levels of risk. From a seismic risk perspective the goal is to manage seismic risk. Seismic risk is determined by convolving the seismic hazard with seismic fragilities (capacity of systems, structures, and components (SSCs)). There are large uncertainties associated with evolving nature of the seismic hazard curves. Additionally there are requirements within DOE and potential requirements within NRC to reconsider updated seismic hazard curves every 10 years. Therefore opportunity exists for engineered solutions to manage this seismic uncertainty. One engineered solution is seismic isolation. Current seismic isolation (SI) designs (used in commercial industry) reduce horizontal earthquake loads and protect critical infrastructure from the potentially destructive effects of large earthquakes. The benefit of SI application in the nuclear industry is being recognized and SI systems have been proposed, in the American Society of Civil Engineers (ASCE) 4 standard, to be released in 2014, for Light Water Reactors (LWR) facilities using commercially available technology. However, there is a lack of industry application to the nuclear industry and uncertainty with implementing the procedures outlined in ASCE-4. Opportunity exists to determine barriers associated with implementation of current ASCE-4 standard language.

  4. LLNL's Regional Seismic Discrimination Research

    International Nuclear Information System (INIS)

    Hanley, W; Mayeda, K; Myers, S; Pasyanos, M; Rodgers, A; Sicherman, A; Walter, W

    1999-01-01

    As part of the Department of Energy's research and development effort to improve the monitoring capability of the planned Comprehensive Nuclear-Test-Ban Treaty international monitoring system, Lawrence Livermore Laboratory (LLNL) is testing and calibrating regional seismic discrimination algorithms in the Middle East, North Africa and Western Former Soviet Union. The calibration process consists of a number of steps: (1) populating the database with independently identified regional events; (2) developing regional boundaries and pre-identifying severe regional phase blockage zones; (3) measuring and calibrating coda based magnitude scales; (4a) measuring regional amplitudes and making magnitude and distance amplitude corrections (MDAC); (4b) applying the DOE modified kriging methodology to MDAC results using the regionalized background model; (5) determining the thresholds of detectability of regional phases as a function of phase type and frequency; (6) evaluating regional phase discriminant performance both singly and in combination; (7) combining steps 1-6 to create a calibrated discrimination surface for each stations; (8) assessing progress and iterating. We have now developed this calibration procedure to the point where it is fairly straightforward to apply earthquake-explosion discrimination in regions with ample empirical data. Several of the steps outlined above are discussed in greater detail in other DOE papers in this volume or in recent publications. Here we emphasize the results of the above process: station correction surfaces and their improvement to discrimination results compared with simpler calibration methods. Some of the outstanding discrimination research issues involve cases in which there is little or no empirical data. For example in many cases there is no regional nuclear explosion data at IMS stations or nearby surrogates. We have taken two approaches to this problem, first finding and using mining explosion data when available, and

  5. Earthquake Monitoring with the MyShake Global Smartphone Seismic Network

    Science.gov (United States)

    Inbal, A.; Kong, Q.; Allen, R. M.; Savran, W. H.

    2017-12-01

    Smartphone arrays have the potential for significantly improving seismic monitoring in sparsely instrumented urban areas. This approach benefits from the dense spatial coverage of users, as well as from communication and computational capabilities built into smartphones, which facilitate big seismic data transfer and analysis. Advantages in data acquisition with smartphones trade-off with factors such as the low-quality sensors installed in phones, high noise levels, and strong network heterogeneity, all of which limit effective seismic monitoring. Here we utilize network and array-processing schemes to asses event detectability with the MyShake global smartphone network. We examine the benefits of using this network in either triggered or continuous modes of operation. A global database of ground motions measured on stationary phones triggered by M2-6 events is used to establish detection probabilities. We find that the probability of detecting an M=3 event with a single phone located 20 nearby phones closely match the regional catalog locations. We use simulated broadband seismic data to examine how location uncertainties vary with user distribution and noise levels. To this end, we have developed an empirical noise model for the metropolitan Los-Angeles (LA) area. We find that densities larger than 100 stationary phones/km2 are required to accurately locate M 2 events in the LA basin. Given the projected MyShake user distribution, that condition may be met within the next few years.

  6. Expected Seismicity and the Seismic Noise Environment of Europa

    Science.gov (United States)

    Panning, Mark P.; Stähler, Simon C.; Huang, Hsin-Hua; Vance, Steven D.; Kedar, Sharon; Tsai, Victor C.; Pike, William T.; Lorenz, Ralph D.

    2018-01-01

    Seismic data will be a vital geophysical constraint on internal structure of Europa if we land instruments on the surface. Quantifying expected seismic activity on Europa both in terms of large, recognizable signals and ambient background noise is important for understanding dynamics of the moon, as well as interpretation of potential future data. Seismic energy sources will likely include cracking in the ice shell and turbulent motion in the oceans. We define a range of models of seismic activity in Europa's ice shell by assuming each model follows a Gutenberg-Richter relationship with varying parameters. A range of cumulative seismic moment release between 1016 and 1018 Nm/yr is defined by scaling tidal dissipation energy to tectonic events on the Earth's moon. Random catalogs are generated and used to create synthetic continuous noise records through numerical wave propagation in thermodynamically self-consistent models of the interior structure of Europa. Spectral characteristics of the noise are calculated by determining probabilistic power spectral densities of the synthetic records. While the range of seismicity models predicts noise levels that vary by 80 dB, we show that most noise estimates are below the self-noise floor of high-frequency geophones but may be recorded by more sensitive instruments. The largest expected signals exceed background noise by ˜50 dB. Noise records may allow for constraints on interior structure through autocorrelation. Models of seismic noise generated by pressure variations at the base of the ice shell due to turbulent motions in the subsurface ocean may also generate observable seismic noise.

  7. Seismic motions from project Rulison

    International Nuclear Information System (INIS)

    Loux, P.C.

    1970-01-01

    In the range from a few to a few hundred km, seismic measurements from the Rulison event are shown and compared with experimentally and analytically derived pre-event estimates. Seismograms, peak accelerations, and response spectra are given along with a description of the associated geologic environment. Techniques used for the pre-event estimates are identified with emphasis on supportive data and on Rulison results. Of particular interest is the close-in seismic frequency content which is expected to contain stronger high frequency components. This higher frequency content translates into stronger accelerations within the first tens of km, which in turn affect safety preparations. Additionally, the local geologic structure at nearby population centers must be considered. Pre-event reverse profile refraction surveys are used to delineate the geology at Rifle, Rulison, Grand Valley, and other sites. The geologic parameters are then used as input to seismic amplification models which deliver estimates of local resonant frequencies. Prediction of such resonances allows improved safety assurance against seismic effects hazards. (author)

  8. Multicomponent ensemble models to forecast induced seismicity

    Science.gov (United States)

    Király-Proag, E.; Gischig, V.; Zechar, J. D.; Wiemer, S.

    2018-01-01

    In recent years, human-induced seismicity has become a more and more relevant topic due to its economic and social implications. Several models and approaches have been developed to explain underlying physical processes or forecast induced seismicity. They range from simple statistical models to coupled numerical models incorporating complex physics. We advocate the need for forecast testing as currently the best method for ascertaining if models are capable to reasonably accounting for key physical governing processes—or not. Moreover, operational forecast models are of great interest to help on-site decision-making in projects entailing induced earthquakes. We previously introduced a standardized framework following the guidelines of the Collaboratory for the Study of Earthquake Predictability, the Induced Seismicity Test Bench, to test, validate, and rank induced seismicity models. In this study, we describe how to construct multicomponent ensemble models based on Bayesian weightings that deliver more accurate forecasts than individual models in the case of Basel 2006 and Soultz-sous-Forêts 2004 enhanced geothermal stimulation projects. For this, we examine five calibrated variants of two significantly different model groups: (1) Shapiro and Smoothed Seismicity based on the seismogenic index, simple modified Omori-law-type seismicity decay, and temporally weighted smoothed seismicity; (2) Hydraulics and Seismicity based on numerically modelled pore pressure evolution that triggers seismicity using the Mohr-Coulomb failure criterion. We also demonstrate how the individual and ensemble models would perform as part of an operational Adaptive Traffic Light System. Investigating seismicity forecasts based on a range of potential injection scenarios, we use forecast periods of different durations to compute the occurrence probabilities of seismic events M ≥ 3. We show that in the case of the Basel 2006 geothermal stimulation the models forecast hazardous levels

  9. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.

    2015-12-01

    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single for