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Sample records for lz complexity distance

  1. LZ Complexity Distance of DNA Sequences and Its Application in Phylogenetic Tree Reconstruction

    Institute of Scientific and Technical Information of China (English)

    Bin Li; Yi-Bing Li; Hong-Bo He

    2005-01-01

    DNA sequences can be treated as finite-length symbol strings over a four-letter alphabet (A, C, T, G). As a universal and computable complexity measure, LZ complexity is valid to describe the complexity of DNA sequences. In this study, a concept of conditional LZ complexity between two sequences is proposed according to the principle of LZ complexity measure. An LZ complexity distance metric between two nonnull sequences is defined by utilizing conditional LZ complexity.Based on LZ complexity distance, a phylogenetic tree of 26 species of placental mammals (Eutheria) with three outgroup species was reconstructed from their complete mitochondrial genomes. On the debate that which two of the three main groups of placental mammals, namely Primates, Ferungulates, and Rodents, are more closely related, the phylogenetic tree reconstructed based on LZ complexity distance supports the suggestion that Primates and Ferungulates are more closely related.

  2. LZ complexity in chaotic dynamical systems and the quasiperiodic Fibonacci sequence

    Directory of Open Access Journals (Sweden)

    D. Arasteh

    1998-04-01

    Full Text Available   The origin the concept of LZ compexity is in information science. Here we use this notion to characterize chaotic dynamical systems. We make contact with the usual characteristics of chaos, such as Lyapunov exponent and K-entropy. It is shown that for a two-dimensional system LZ complexity is as powerful as other characteristics. We also apply LZ complexity to the study of the quasiperiodic Fibonacci sequence. We prove a theorem about its LZ complexity and based upon it conclude its long range order.

  3. Prediction of Antimicrobial Peptides Based on Sequence Alignment and Support Vector Machine-Pairwise Algorithm Utilizing LZ-Complexity

    Directory of Open Access Journals (Sweden)

    Xin Yi Ng

    2015-01-01

    Full Text Available This study concerns an attempt to establish a new method for predicting antimicrobial peptides (AMPs which are important to the immune system. Recently, researchers are interested in designing alternative drugs based on AMPs because they have found that a large number of bacterial strains have become resistant to available antibiotics. However, researchers have encountered obstacles in the AMPs designing process as experiments to extract AMPs from protein sequences are costly and require a long set-up time. Therefore, a computational tool for AMPs prediction is needed to resolve this problem. In this study, an integrated algorithm is newly introduced to predict AMPs by integrating sequence alignment and support vector machine- (SVM- LZ complexity pairwise algorithm. It was observed that, when all sequences in the training set are used, the sensitivity of the proposed algorithm is 95.28% in jackknife test and 87.59% in independent test, while the sensitivity obtained for jackknife test and independent test is 88.74% and 78.70%, respectively, when only the sequences that has less than 70% similarity are used. Applying the proposed algorithm may allow researchers to effectively predict AMPs from unknown protein peptide sequences with higher sensitivity.

  4. Prograde garnet growth along complex P T t paths: results from numerical experiments on polyphase garnet from the Wölz Complex (Austroalpine basement)

    Science.gov (United States)

    Gaidies, F.; de Capitani, C.; Abart, R.; Schuster, R.

    2008-06-01

    Garnet in metapelites from the Wölz Complex of the Austroalpine crystalline basement east of the Tauern Window characteristically consists of two growth phases, which preserve a comprehensive record of the geothermal history during polymetamorphism. From numerical modelling of garnet formation, detailed information on the pressure temperature time ( P T t) evolution during prograde metamorphism is obtained. In that respect, the combined influences of chemical fractionation associated with garnet growth, modification of the original growth zoning through intragranular diffusion and the nucleation history on the chemical zoning of garnet as P and T change during growth are considered. The concentric chemical zoning observed in garnet and the homogenous rock matrix, which is devoid of chemical segregation, render the simulation of garnet growth through successive equilibrium states reliable. Whereas the first growth phase of garnet was formed at isobaric conditions of ˜3.8 kbar at low heating/cooling rates, the second growth phase grew along a Barrovian P T path marked with a thermal peak of ˜625°C at ˜10 kbar and a maximum in P of ˜10.4 kbar at ˜610°C. For the heating rate during the growth of the second phase of garnet, average rates faster than 50°C Ma-1 are obtained. From geochronological investigations the first growth phase of garnet from the Wölz Complex pertains to the Permian metamorphic event. The second growth phase grew in the course of Eo-Alpine metamorphism during the Cretaceous.

  5. Graph distance for complex networks

    Science.gov (United States)

    Shimada, Yutaka; Hirata, Yoshito; Ikeguchi, Tohru; Aihara, Kazuyuki

    2016-10-01

    Networks are widely used as a tool for describing diverse real complex systems and have been successfully applied to many fields. The distance between networks is one of the most fundamental concepts for properly classifying real networks, detecting temporal changes in network structures, and effectively predicting their temporal evolution. However, this distance has rarely been discussed in the theory of complex networks. Here, we propose a graph distance between networks based on a Laplacian matrix that reflects the structural and dynamical properties of networked dynamical systems. Our results indicate that the Laplacian-based graph distance effectively quantifies the structural difference between complex networks. We further show that our approach successfully elucidates the temporal properties underlying temporal networks observed in the context of face-to-face human interactions.

  6. Lz-0 × Berkeley: a new Arabidopsis recombinant inbred line population for the mapping of complex traits.

    Science.gov (United States)

    Capron, Arnaud; Chang, Xue Feng; Shi, Chun; Beatson, Rodger; Berleth, Thomas

    2014-06-01

    This study describes the generation and test of a genetic resource suited to identify determinants of cell biological traits in plants. The use of quantitative trait loci (QTL) mapping for a better genetic understanding of cell biological traits is still at an early stage, even for biotechnologically important cell properties, such as the dimensions of fiber cells. A common strategy, the mapping of QTLs in recombinant inbred line (RIL) populations, is limited by the fact that the existing RIL populations exploit only a small fraction of the existing natural variation. Here, we report the mapping of QTLs impacting on the length of fiber cells in Arabidopsis inflorescence stems in a newly generated RIL population derived from a cross between the accessions Berkeley and the little known Lz-0. Through inbreeding of individual F(2) plants, a total of 159 new F8 lines were produced and genotyped with a set of 49 single nucleotide polymorphism markers. The population was successfully used not only for the mapping of three QTLs controlling fiber length, but also to map five QTL controlling flowering time under short and long-day conditions. Our study demonstrates the usefulness of this new genetic resource by mapping in it QTLs underlying a poorly explored cellular trait as well as an already better explored regulatory pathway. The new RIL population and an online platform for the continuous supplementation of genetic markers will be generally available to substantially broaden the genetic diversity through which loci with impact on plant quantitative traits can be identified.

  7. The LZ dark matter experiment

    Science.gov (United States)

    McKinsey, D. N.; LZ Collaboration

    2016-05-01

    The LUX and ZEPLIN collaborations have merged to construct a 7 tonne two-phase Xe dark matter detector, known as LUX-ZEPLIN or LZ. Chosen as one of the Generation 2 suite of dark matter direct detection experiments, LZ will probe spin-independent WIMP-nucleon cross sections down to 2 × 10-48 cm2 at 50 GeV/c2 within 3 years of operation, covering a substantial range of theoretically-motivated dark matter candidates. Along with dark matter interactions with Xe nuclei, LZ will also be sensitive to solar neutrinos emitted by the pp fusion process in the sun, neutrinos emitted by a nearby supernova and detected by coherent neutrino-nucleus scattering, certain classes of axions and axion-like particles, and neutrinoless double-beta decay of 136Xe. The design of LZ is presented, along with its expected backgrounds and projected sensitivity.

  8. After LUX: The LZ Program

    CERN Document Server

    Malling, D C; Araujo, H M; Bai, X; Bedikian, S; Bernard, E; Bernstein, A; Bradley, A; Cahn, S B; Carmona-Benitez, M C; Carr, D; Chapman, J J; Clark, K; Classen, T; Coffey, T; Curioni, A; Currie, A; Dazeley, S; de Viveiros, L; Dragowsky, M; Druszkiewicz, E; Faham, C H; Fiorucci, S; Gaitskell, R J; Gibson, K R; Hall, C; Hanhardt, M; Holbrook, B; Ihm, M; Jacobsen, R G; Kastens, L; Kazkaz, K; Lander, R; Larsen, N; Lee, C; Leonard, D; Lesko, K; Lyashenko, A; Majewski, P; Mannino, R; McKinsey, D N; Mei, D -M; Mock, J; Morii, M; Murphy, A St J; Nelson, H; Nikkel, J A; Pangilinan, M; Phelps, P; Reichhart, L; Shutt, T; Skulski, W; Sorensen, P; Spaans, J; Stiegler, T; Sumner, T J; Svoboda, R; Sweany, M; Szydagis, M; Thomson, J; Tripathi, M; Verbus, J R; Walsh, N; Webb, R; White, J T; Wlasenko, M; Wolfs, F L H; Woods, M; Zhang, C

    2011-01-01

    The LZ program consists of two stages of direct dark matter searches using liquid Xe detectors. The first stage will be a 1.5-3 tonne detector, while the last stage will be a 20 tonne detector. Both devices will benefit tremendously from research and development performed for the LUX experiment, a 350 kg liquid Xe dark matter detector currently operating at the Sanford Underground Laboratory. In particular, the technology used for cryogenics and electrical feedthroughs, circulation and purification, low-background materials and shielding techniques, electronics, calibrations, and automated control and recovery systems are all directly scalable from LUX to the LZ detectors. Extensive searches for potential background sources have been performed, with an emphasis on previously undiscovered background sources that may have a significant impact on tonne-scale detectors. The LZ detectors will probe spin-independent interaction cross sections as low as 5E-49 cm2 for 100 GeV WIMPs, which represents the ultimate limi...

  9. The Dynamic Range of LZ

    CERN Document Server

    Yin, Jun

    2015-01-01

    The electronics of the LZ experiment, the 7-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), is designed to permit studies of physics where the energies deposited range from 1 keV of nuclear-recoil energy up to 3,000 keV of electron-recoil energy. The system is designed to provide a 70% efficiency for events that produce three photoelectrons in the photomultiplier tubes (PMTs). This corresponds approximately to the lowest energy threshold achievable in such a detector, and drives the noise specifications for the front end. The upper limit of the LZ dynamic range is defined by the electroluminescence (S2) signals. The low-energy channels of the LZ amplifiers provide the dynamic range required for the tritium and krypton calibrations. The high-energy channels provide the dynamic range required to measure the activated Xe lines. S2 signals induced by alpha particles from radon decay will saturate one or more channels of the top PMT array but techniques are being dev...

  10. LUX-ZEPLIN (LZ) Conceptual Design Report

    CERN Document Server

    Akerib, D S; Akimov, D. Yu.; Alsum, S.K.; Araújo, H.M.; Bai, X.; Bailey, A.J.; Balajthy, J.; Balashov, S.; Barry, M.J.; Bauer, P.; Beltrame, P.; Bernard, E.P.; Bernstein, A.; Biesiadzinski, T.P.; Boast, K.E.; Bolozdynya, A.I.; Boulton, E.M.; Bramante, R.; Buckley, J.H.; Bugaev, V.V.; Bunker, R.; Burdin, S.; Busenitz, J.K.; Carels, C.; Carlsmith, D.L.; Carlson, B.; Carmona-Benitez, M.C.; Cascella, M.; Chan, C.; Cherwinka, J.J.; Chiller, A.A.; Chiller, C.; Craddock, W.W.; Currie, A.; Cutter, J.E.; da Cunha, J.P.; Dahl, C.E.; Dasu, S.; Davison, T.J.R.; de Viveiros, L.; Dobi, A.; Dobson, J.E.Y.; Druszkiewicz, E.; Edberg, T.K.; Edwards, B.N.; Edwards, W.R.; Elnimr, M.M.; Emmet, W.T.; Faham, C.H.; Fiorucci, S.; Ford, P.; Francis, V.B.; Fu, C.; Gaitskell, R.J.; Gantos, N.J.; Gehman, V.M.; Gerhard, R.M.; Ghag, C.; Gilchriese, M.G.D.; Gomber, B.; Hall, C.R.; Harris, A.; Haselschwardt, S.J.; Hertel, S.A.; Hoff, M.D.; Holbrook, B.; Holtom, E.; Huang, D.Q.; Hurteau, T.W.; Ignarra, C.M.; Jacobsen, R.G.; Ji, W.; Ji, X.; Johnson, M.; Ju, Y.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Khazov, A.; Khromov, A.V.; Konovalov, A.M.; Korolkova, E.V.; Kraus, H.; Krebs, H.J.; Kudryavtsev, V.A.; Kumpan, A.V.; Kyre, S.; Larsen, N.A.; Lee, C.; Lenardo, B.G.; Lesko, K.T.; Liao, F. -T.; Lin, J.; Lindote, A.; Lippincott, W.H.; Liu, J.; Liu, X.; Lopes, M.I.; Lorenzon, W.; Luitz, S.; Majewski, P.; Malling, D.C.; Manalaysay, A.G.; Manenti, L.; Mannino, R.L.; Markley, D.J.; Martin, T.J.; Marzioni, M.F.; McKinsey, D.N.; Mei, D. -M.; Meng, Y.; Miller, E.H.; Mock, J.; Monzani, M.E.; Morad, J.A.; Murphy, A. St. J.; Nelson, H.N.; Neves, F.; Nikkel, J.A.; O'Neill, F.G.; O'Dell, J.; O'Sullivan, K.; Olevitch, M.A.; Oliver-Mallory, K.C.; Palladino, K.J.; Pangilinan, M.; Patton, S.J.; Pease, E.K.; Piepke, A.; Powell, S.; Preece, R.M.; Pushkin, K.; Ratcliff, B.N.; Reichenbacher, J.; Reichhart, L.; Rhyne, C.; Rodrigues, J.P.; Rose, H.J.; Rosero, R.; Saba, J.S.; Sarychev, M.; Schnee, R.W.; Schubnell, M.S.G.; Scovell, P.R.; Shaw, S.; Shutt, T.A.; Silva, C.; Skarpaas, K.; Skulski, W.; Solovov, V.N.; Sorensen, P.; Sosnovtsev, V.V.; Stancu, I.; Stark, M.R.; Stephenson, S.; Stiegler, T.M.; Sumner, T.J.; Sundarnath, K.; Szydagis, M.; Taylor, D.J.; Taylor, W.; Tennyson, B.P.; Terman, P.A.; Thomas, K.J.; Thomson, J.A.; Tiedt, D.R.; To, W.H.; Tomás, A.; Tripathi, M.; Tull, C.E.; Tvrznikova, L.; Uvarov, S.; Va'vra, J.; van der Grinten, M.G.D.; Verbus, J.R.; Vuosalo, C.O.; Waldron, W.L.; Wang, L.; Webb, R.C.; Wei, W. -Z.; While, M.; White, D.T.; Whitis, T.J.; Wisniewski, W.J.; Witherell, M.S.; Wolfs, F.L.H.; Woods, E.; Woodward, D.; Worm, S.D.; Yeh, M.; Yin, J.; Young, S.K.; Zhang, C.

    2015-01-01

    The design and performance of the LUX-ZEPLIN (LZ) detector is described as of March 2015 in this Conceptual Design Report. LZ is a second-generation dark-matter detector with the potential for unprecedented sensitivity to weakly interacting massive particles (WIMPs) of masses from a few GeV/c2 to hundreds of TeV/c2. With total liquid xenon mass of about 10 tonnes, LZ will be the most sensitive experiment for WIMPs in this mass region by the end of the decade. This report describes in detail the design of the LZ technical systems. Expected backgrounds are quantified and the performance of the experiment is presented. The LZ detector will be located at the Sanford Underground Research Facility in South Dakota. The organization of the LZ Project and a summary of the expected cost and current schedule are given.

  11. LUX-ZEPLIN (LZ) Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Akerib, D. S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); et al.

    2015-03-09

    The design and performance of the LUX-ZEPLIN (LZ) detector is described as of March 2015 in this Conceptual Design Report. LZ is a second-generation dark-matter detector with the potential for unprecedented sensitivity to weakly interacting massive particles (WIMPs) of masses from a few GeV/c2 to hundreds of TeV/c2. With total liquid xenon mass of about 10 tonnes, LZ will be the most sensitive experiment for WIMPs in this mass region by the end of the decade. This report describes in detail the design of the LZ technical systems. Expected backgrounds are quantified and the performance of the experiment is presented. The LZ detector will be located at the Sanford Underground Research Facility in South Dakota. The organization of the LZ Project and a summary of the expected cost and current schedule are given.

  12. The Dynamic Range of LZ

    OpenAIRE

    Yin, Jun

    2015-01-01

    The electronics of the LZ experiment, the 7-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), is designed to permit studies of physics where the energies deposited range from 1 keV of nuclear-recoil energy up to 3,000 keV of electron-recoil energy. The system is designed to provide a 70% efficiency for events that produce three photoelectrons in the photomultiplier tubes (PMTs). This corresponds approximately to the lowest energy threshold achieva...

  13. Lz-transform and inverse Lz-transform application to dynamic reliability assessment for multi-state system

    DEFF Research Database (Denmark)

    Lisnianski, A.; Ding, Y.

    2014-01-01

    The paper presents a new method for reliability assessment for complex multi-state system. The system and its components can have different performance levels ranging from perfect functioning to complete failure. Straightforward Markov method applied to solve the problem will require building...... such as reliability function, mean time to failure etc. inverse LZ-transform is using that completely reveals underlying output process....

  14. Invariant distances and metrics in complex analysis

    CERN Document Server

    Jarnicki, Marek

    2013-01-01

    As in the field of ""Invariant Distances and Metrics in Complex Analysis"" there was and is a continuous progress this is the second extended edition of the corresponding monograph. This comprehensive book is about the study of invariant pseudodistances (non-negative functions on pairs of points) and pseudometrics (non-negative functions on the tangent bundle) in several complex variables. It is an overview over a highly active research area at the borderline between complex analysis, functional analysis and differential geometry. New chapters are covering the Wu, Bergman and several other met

  15. LUX-ZEPLIN (LZ) Technical Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Mount, B. J. [Black Hills State Univ., Spearfish, SD (United States); et al.

    2017-03-27

    In this Technical Design Report (TDR) we describe the LZ detector to be built at the Sanford Underground Research Facility (SURF). The LZ dark matter experiment is designed to achieve sensitivity to a WIMP-nucleon spin-independent cross section of three times ten to the negative forty-eighth square centimeters.

  16. Sequence distance via parsing complexity: Heartbeat signals

    Energy Technology Data Exchange (ETDEWEB)

    Degli Esposti, M. [Department of Mathematics, University of Bologna (Italy)], E-mail: desposti@dm.unibo.it; Farinelli, C. [Department of Mathematics, University of Bologna (Italy)], E-mail: farinelli@dm.unibo.it; Menconi, G. [Department of Mathematics, University of Bologna (Italy)], E-mail: menconi@dm.unibo.it

    2009-02-15

    We compare and discuss the use of different symbolic codings of electrocardiogram (ECG) signals in order to distinguish healthy patients from hospitalized ones. To this aim, we recall a parsing-based similarity distance and compare the performances of several methods of classification of data.

  17. The Gould's Belt Distances Survey (GOBELINS) III. The distance to the Serpens/Aquila Molecular Complex

    CERN Document Server

    Ortiz-León, Gisela N; Kounkel, Marina A; Loinard, Laurent; Mioduszewski, Amy J; Rodríguez, Luis F; Torres, Rosa M; Pech, Gerardo; Rivera, Juana L; Hartmann, Lee; Boden, Andrew F; Evans, Neal J; Briceño, Cesar; Tobin, John J; Galli, Phillip A B

    2016-01-01

    We report on new distances and proper motions to seven stars across the Serpens/Aquila complex. The observations were obtained as part of the Gould's Belt Distances Survey (GOBELINS) project between September 2013 and April 2016 with the Very Long Baseline Array (VLBA). One of our targets is the proto-Herbig AeBe object EC 95, which is a binary system embedded in the Serpens Core. For this system, we combined the GOBELINS observations with previous VLBA data to cover a total period of ~8 years, and derive the orbital elements and an updated source distance. The individual distances to sources in the complex are fully consistent with each other, and the mean value corresponds to a distance of $436.0\\pm9.2$~pc for the Serpens/W40 complex. Given this new evidence, we argue that Serpens Main, W40 and Serpens South are physically associated and form a single cloud structure.

  18. Signal processing and electronic noise in LZ

    Science.gov (United States)

    Khaitan, D.

    2016-03-01

    The electronics of the LUX-ZEPLIN (LZ) experiment, the 10-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), consists of low-noise dual-gain amplifiers and a 100-MHz, 14-bit data acquisition system for the TPC PMTs. Pre-prototypes of the analog amplifiers and the 32-channel digitizers were tested extensively with simulated pulses that are similar to the prompt scintillation light and the electroluminescence signals expected in LZ. These studies are used to characterize the noise and to measure the linearity of the system. By increasing the amplitude of the test signals, the effect of saturating the amplifier and the digitizers was studied. The RMS ADC noise of the digitizer channels was measured to be 1.19± 0.01 ADCC. When a high-energy channel of the amplifier is connected to the digitizer, the measured noise remained virtually unchanged, while the noise added by a low-energy channel was estimated to be 0.38 ± 0.02 ADCC (46 ± 2 μV). A test facility is under construction to study saturation, mitigate noise and measure the performance of the LZ electronics and data acquisition chain.

  19. Distances to galactic high-velocity clouds : Complex C

    NARCIS (Netherlands)

    Wakker, B. P.; York, D. G.; Howk, J. C.; Barentine, J. C.; Wilhelm, R.; Peletier, R. F.; van Woerden, H.; Beers, T. C.; Ivezic, Z.; Richter, P.; Schwarz, U. J.

    2007-01-01

    We report the first determination of a distance bracket for the high- velocity cloud (HVC) complex C. Combined with previous measurements showing that this cloud has a metallicity of 0.15 times solar, these results provide ample evidence that complex C traces the continuing accretion of intergalacti

  20. Distances to galactic high-velocity clouds : Complex C

    NARCIS (Netherlands)

    Wakker, B. P.; York, D. G.; Howk, J. C.; Barentine, J. C.; Wilhelm, R.; Peletier, R. F.; van Woerden, H.; Beers, T. C.; Ivezic, Z.; Richter, P.; Schwarz, U. J.

    2007-01-01

    We report the first determination of a distance bracket for the high- velocity cloud (HVC) complex C. Combined with previous measurements showing that this cloud has a metallicity of 0.15 times solar, these results provide ample evidence that complex C traces the continuing accretion of intergalacti

  1. Signal Processing and Electronic Noise in LZ

    CERN Document Server

    Khaitan, Dev Ashish

    2015-01-01

    The electronics of the LUX-ZEPLIN (LZ) experiment, the 10-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), consists of low-noise dual-gain amplifiers and a 100-MHz, 14-bit data acquisition system for the TPC PMTs. Pre-prototypes of the analog amplifiers and the 32-channel digitizers were tested extensively with simulated pulses that are similar to the prompt scintillation light and the electroluminescence signals expected in LZ. These studies are used to characterize the noise and to measure the linearity of the system. By increasing the amplitude of the test signals, the effect of saturating the amplifier and the digitizers was studied. The RMS ADC noise of the digitizer channels was measured to be 1.19 $\\pm$ 0.01 ADCC. When a high-energy channel of the amplifier is connected to the digitizer, the measured noise remained virtually unchanged, while the noise added by a low-energy channel was estimated to be 0.38 $\\pm$ 0.02 ADCC (46 $\\pm$ 2$\\mu$V). A test facility...

  2. The Data Acquisition System for LZ

    CERN Document Server

    Druszkiewicz, Eryk

    2015-01-01

    The Data Acquisition System of the LZ experiment, the 10-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), will collect signals from 788 photomultiplier tubes (PMTs). Because the signals from the time projection chamber PMTs will be passed through dual-gain amplifiers, the DAQ system will collect waveforms from a total of 1276 channels, using custom built, 32-channel, FPGA-based digital signal processors. The appropriately conditioned signals will be digitized at 100 MHz with 14-bit resolution. Based on actual measurements with a small-scale prototype system, the LZ DAQ is expected to be able to handle a maximum sparsified data rate of ~1500 MB/s. During calibrations, it is estimated that only 33% of the system resources are utilized. The digital filters that are used for data selection operate with an aggregate throughput in excess of 595,000 MB/s. Data selection decisions are based on, for example, the amount of scintillation (S1) and photoluminescence S2 light,...

  3. The Communication Complexity of the Hamming Distance Problem

    OpenAIRE

    Huang, Wei; Shi, Yaoyun; Zhang, Shengyu; Zhu, Yufan

    2005-01-01

    We investigate the randomized and quantum communication complexity of the Hamming Distance problem, which is to determine if the Hamming distance between two n-bit strings is no less than a threshold d. We prove a quantum lower bound of \\Omega(d) qubits in the general interactive model with shared prior entanglement. We also construct a classical protocol of O(d \\log d) bits in the restricted Simultaneous Message Passing model, improving previous protocols of O(d^2) bits (A. C.-C. Yao, Procee...

  4. Distances in Probability Space and the Statistical Complexity Setup

    Directory of Open Access Journals (Sweden)

    Montserrat Casas

    2011-06-01

    Full Text Available Statistical complexity measures (SCM are the composition of two ingredients: (i entropies and (ii distances in probability-space. In consequence, SCMs provide a simultaneous quantification of the randomness and the correlational structures present in the system under study. We address in this review important topics underlying the SCM structure, viz., (a a good choice of probability metric space and (b how to assess the best distance-choice, which in this context is called a “disequilibrium” and is denoted with the letter Q. Q, indeed the crucial SCM ingredient, is cast in terms of an associated distance D. Since out input data consists of time-series, we also discuss the best way of extracting from the time series a probability distribution P. As an illustration, we show just how these issues affect the description of the classical limit of quantum mechanics.

  5. On the Complexity of Rearrangement Problems under the Breakpoint Distance

    CERN Document Server

    Kovac, Jakub

    2011-01-01

    Tannier et al. introduced a generalization of breakpoint distance for multichromosomal genomes. They showed that the median problem under the breakpoint distance is solvable in polynomial time in the multichromosomal circular and mixed models. This is intriguing, since in all other rearrangement models (DCJ, reversal, unichromosomal or multilinear breakpoint models), the problem is NP-hard. The complexity of the small or even the large phylogeny problem under the breakpoint distance remained an open problem. We improve the algorithm for the median problem and show that it is equivalent to the problem of finding maximum cardinality non-bipartite matching (under linear reduction). On the other hand, we prove that the more general small phylogeny problem is NP-hard. Surprisingly, we show that it is already NP-hard (or even APX-hard) for 4 species (a quartet phylogeny). In other words, while finding an ancestor for 3 species is easy, already finding two ancestors for 4 species is hard. We also show that, in the u...

  6. Hipparcos distances of Ophiuchus and Lupus cloud complexes

    CERN Document Server

    Lombardi, M; Alves, J

    2008-01-01

    We combine extinction maps from the Two Micron All Sky Survey (2MASS) with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood approach, shows that the rho-Ophiuchi cloud is located at (119 +/- 6) pc and the Lupus complex is located at 115 +/- 8 pc; in addition, we are able to put constraints on the thickness of the clouds and on their orientation on the sky (both these effects are not included in the error estimate quoted above). For Ophiuchus, we find some evidence that the streamers are closer to us than the core. The method applied in this paper is currently limited to nearby molecular clouds, but it will find many natural applications in the GAIA-era, when it will be possible to pin down the distance and three-dimensional structure of virtually every molecular cloud in the Galaxy.

  7. Managing Complex Distance Education Projects in a Telework Environment

    Science.gov (United States)

    Ally, Mohamed; Cleveland-Innes, Marti; Wiseman, Colin

    2010-01-01

    The advances of communication technologies have allowed professionals to work on distance education projects in a telework environment. Managers of these projects must have the skills to manage the projects from a distance. They must be able to select the appropriate team members to work on the project, orient team members, and monitor team…

  8. The Gould's Belt Distances Survey (GOBELINS) I. Trigonometric parallax distances and depth of the Ophiuchus complex

    CERN Document Server

    Ortiz-León, Gisela N; Kounkel, Marina A; Dzib, Sergio A; Mioduszewski, Amy J; Rodríguez, Luis F; Torres, Rosa M; González-Lópezlira, Rosa A; Pech, Gerardo; Rivera, Juana L; Hartmann, Lee; Boden, Andrew F; Evans, Neal J; Briceño, Cesar; Tobin, John J; Galli, Phillip A B; Gudehus, Donald

    2016-01-01

    We present the first results of the Gould's Belt Distances Survey (GOBELINS), a project aimed at measuring the proper motion and trigonometric parallax of a large sample of young stars in nearby regions using multi-epoch Very Long Baseline Array (VLBA) radio observations. Enough VLBA detections have now been obtained for 16 stellar systems in Ophiuchus to derive their parallax and proper motion. This leads to distance determinations for individual stars with an accuracy of 0.3 to a few percent. In addition, the orbits of 6 multiple systems were modelled by combining absolute positions with VLBA (and in some cases, near infrared) angular separations. Twelve stellar systems are located in the dark cloud Lynds 1688, the individual distances for this sample are highly consistent with one another, and yield a mean parallax for Lynds 1688 of $\\varpi=7.28\\pm0.06$ mas, corresponding to a distance $d=137.3\\pm1.2$ pc. This represents an accuracy better than 1%. Three systems for which astrometric elements could be meas...

  9. Cloning and prokaryotic expression of lz8 gene and immunoblotting detection of LZ-8, an immunomodulatory protein from Ganoderma lucidum%灵芝lz8基因的克隆和原核表达及LZ-8蛋白的免疫印迹检测

    Institute of Scientific and Technical Information of China (English)

    丁一新; 赵明文

    2006-01-01

    根据已报道的lz8基因序列设计引物,以灵芝基因组DNA为模板,PCR扩增获得lz8基因.构建了原核表达载体pET30a-lz8,转化原核表达宿主菌Rosetta DE3, IPTG诱导融合蛋白表达,并用Ni-NTA亲和层析柱对LZ-8蛋白进行分离纯化.将纯化的LZ-8蛋白用Freund佐剂乳化后注射到新西兰白兔体内,经数次加强免疫后采血分离抗血清,并以抗血清为探针建立了LZ-8蛋白的免疫印迹法定性检测方法.

  10. An analytical solution in the complex plane for the luminosity distance in flat cosmology

    CERN Document Server

    Zaninetti, L

    2016-01-01

    We present an analytical solution for the luminosity distance in spatially flat cosmology with pressureless matter and the cosmological constant. The complex analytical solution is made of a real part and a negligible imaginary part. The real part of the luminosity distance allows finding the two parameters $H_0$ and $\\om$. A simple expression for the distance modulus for SNs of type Ia is reported in the framework of the minimax approximation.

  11. Effective distances for epidemics spreading on complex networks

    Science.gov (United States)

    Iannelli, Flavio; Koher, Andreas; Brockmann, Dirk; Hövel, Philipp; Sokolov, Igor M.

    2017-01-01

    We show that the recently introduced logarithmic metrics used to predict disease arrival times on complex networks are approximations of more general network-based measures derived from random walks theory. Using the daily air-traffic transportation data we perform numerical experiments to compare the infection arrival time with this alternative metric that is obtained by accounting for multiple walks instead of only the most probable path. The comparison with direct simulations reveals a higher correlation compared to the shortest-path approach used previously. In addition our method allows to connect fundamental observables in epidemic spreading with the cumulant-generating function of the hitting time for a Markov chain. Our results provides a general and computationally efficient approach using only algebraic methods.

  12. Effective Distances for Epidemics Spreading on Complex Networks

    CERN Document Server

    Iannelli, Flavio; Brockmann, Dirk; Hoevel, Philipp; Sokolov, Igor M

    2016-01-01

    We show that the recently introduced logarithmic metrics used to predict disease arrival times on complex networks are approximations of more general network-based measures derived from random walks theory. Using the daily air-traffic transportation data we perform numerical experiments to compare the infection arrival time with this alternative metric that is obtained by accounting for multiple walks instead of only the most probable path. The comparison with direct simulations of arrival times reveals a higher correlation compared to the shortest path approach used previously. In addition our method allows to connect fundamental observables in epidemic spreading with the cumulant generating function of the hitting time for a Markov chain. Our results provides a general and computationally efficient approach to the problem using only algebraic methods.

  13. The Max b-HLH-LZ can transduce into cells and inhibit c-Myc transcriptional activities.

    Science.gov (United States)

    Montagne, Martin; Beaudoin, Nicolas; Fortin, David; Lavoie, Christine L; Klinck, Roscoe; Lavigne, Pierre

    2012-01-01

    The inhibition of the functions of c-Myc (endogenous and oncogenic) was recently shown to provide a spectacular therapeutic index in cancer mouse models, with complete tumor regression and minimal side-effects in normal tissues. This was achieved by the systemic and conditional expression of omomyc, the cDNA of a designed mutant of the b-HLH-LZ of c-Myc named Omomyc. The overall mode of action of Omomyc consists in the sequestration of Max and the concomitant competition of the Omomyc/Max complex with the endogenous c-Myc/Max heterodimer. This leads to the inhibition of the transactivation of Myc target genes involved in proliferation and metabolism. While this body of work has provided extraordinary insights to guide the future development of new cancer therapies that target c-Myc, Omomyc itself is not a therapeutic agent. In this context, we sought to exploit the use of a b-HLH-LZ to inhibit c-Myc in a cancer cell line in a more direct fashion. We demonstrate that the b-HLH-LZ domain of Max (Max*) behaves as a bona fide protein transduction domain (PTD) that can efficiently transduce across cellular membrane via through endocytosis and translocate to the nucleus. In addition, we show that the treatment of HeLa cells with Max* leads to a reduction of metabolism and proliferation rate. Accordingly, we observe a decrease of the population of HeLa cells in S phase, an accumulation in G1/G0 and the induction of apoptosis. In agreement with these phenotypic changes, we show by q-RT-PCR that the treatment of HeLa cells with Max* leads to the activation of the transcription c-Myc repressed genes as well as the repression of the expression of c-Myc activated genes. In addition to the novel discovery that the Max b-HLH-LZ is a PTD, our findings open up new avenues and strategies for the direct inhibition of c-Myc with b-HLH-LZ analogs.

  14. The Max b-HLH-LZ can transduce into cells and inhibit c-Myc transcriptional activities.

    Directory of Open Access Journals (Sweden)

    Martin Montagne

    Full Text Available The inhibition of the functions of c-Myc (endogenous and oncogenic was recently shown to provide a spectacular therapeutic index in cancer mouse models, with complete tumor regression and minimal side-effects in normal tissues. This was achieved by the systemic and conditional expression of omomyc, the cDNA of a designed mutant of the b-HLH-LZ of c-Myc named Omomyc. The overall mode of action of Omomyc consists in the sequestration of Max and the concomitant competition of the Omomyc/Max complex with the endogenous c-Myc/Max heterodimer. This leads to the inhibition of the transactivation of Myc target genes involved in proliferation and metabolism. While this body of work has provided extraordinary insights to guide the future development of new cancer therapies that target c-Myc, Omomyc itself is not a therapeutic agent. In this context, we sought to exploit the use of a b-HLH-LZ to inhibit c-Myc in a cancer cell line in a more direct fashion. We demonstrate that the b-HLH-LZ domain of Max (Max* behaves as a bona fide protein transduction domain (PTD that can efficiently transduce across cellular membrane via through endocytosis and translocate to the nucleus. In addition, we show that the treatment of HeLa cells with Max* leads to a reduction of metabolism and proliferation rate. Accordingly, we observe a decrease of the population of HeLa cells in S phase, an accumulation in G1/G0 and the induction of apoptosis. In agreement with these phenotypic changes, we show by q-RT-PCR that the treatment of HeLa cells with Max* leads to the activation of the transcription c-Myc repressed genes as well as the repression of the expression of c-Myc activated genes. In addition to the novel discovery that the Max b-HLH-LZ is a PTD, our findings open up new avenues and strategies for the direct inhibition of c-Myc with b-HLH-LZ analogs.

  15. Fixed parameter complexity of distance constrained labeling and uniform channel assignment problems

    OpenAIRE

    Fiala, Jiří; Gavenčiak, Tomáš; Knop, Dušan; Koutecký, Martin; Kratochvíl, Jan

    2015-01-01

    We study computational complexity of the class of distance-constrained graph labeling problems from the fixed parameter tractability point of view. The parameters studied are neighborhood diversity and clique width. We rephrase the distance constrained graph labeling problem as a specific uniform variant of the Channel Assignment problem and show that this problem is fixed parameter tractable when parameterized by the neighborhood diversity together with the largest weight. Consequently, ever...

  16. TPC Grid Design in Lux-Zeplin and LZ System Test

    Science.gov (United States)

    Ji, Wei; Lz Collaboration

    2016-03-01

    The lux-zeplin (lz) project is a dark matter direct detection experiment using liquid xenon in a large time projection chamber. The detection scheme requires an electric drift field and efficient light collection for the scintillation and charge signals, respectively. These requirements lead to design challenges for the thin wire grids and meshes that establish the fields with minimal impact on light collection and field non-uniformity. This talk will present the lz design, as informed by simulations and laboratory tests in the lz system test platform at slac. LUXZEPLIN.

  17. On the Computational Complexity of Degenerate Unit Distance Representations of Graphs

    Science.gov (United States)

    Horvat, Boris; Kratochvíl, Jan; Pisanski, Tomaž

    Some graphs admit drawings in the Euclidean k-space in such a (natural) way, that edges are represented as line segments of unit length. Such embeddings are called k-dimensional unit distance representations. The embedding is strict if the distances of points representing nonadjacent pairs of vertices are different than 1. When two non-adjacent vertices are drawn in the same point, we say that the representation is degenerate. Computational complexity of nondegenerate embeddings has been studied before. We initiate the study of the computational complexity of (possibly) degenerate embeddings. In particular we prove that for every k ≥ 2, deciding if an input graph has a (possibly) degenerate k-dimensional unit distance representation is NP-hard.

  18. Self-Index based on LZ77 (thesis)

    CERN Document Server

    Kreft, Sebastian

    2011-01-01

    Domains like bioinformatics, version control systems, collaborative editing systems (wiki), and others, are producing huge data collections that are very repetitive. That is, there are few differences between the elements of the collection. This fact makes the compressibility of the collection extremely high. For example, a collection with all different versions of a Wikipedia article can be compressed up to the 0.1% of its original space, using the Lempel-Ziv 1977 (LZ77) compression scheme. Many of these repetitive collections handle huge amounts of text data. For that reason, we require a method to store them efficiently, while providing the ability to operate on them. The most common operations are the extraction of random portions of the collection and the search for all the occurrences of a given pattern inside the whole collection. A self-index is a data structure that stores a text in compressed form and allows to find the occurrences of a pattern efficiently. On the other hand, self-indexes can extrac...

  19. A Tractable Complex Network Model based on the Stochastic Mean-field Model of Distance

    OpenAIRE

    Aldous, David J.

    2003-01-01

    Much recent research activity has been devoted to empirical study and theoretical models of complex networks (random graphs) with three qualitative features: power-law degree distribution, local clustering of edges, and small diameter. We point out a new (in this context) platform for such models -- the stochastic mean-field model of distance -- and within this platform study a simple two-parameter proportional attachment model. The model is mathematicallly natural, permits a wide variety of ...

  20. The First Distance Constraint on the Renegade High Velocity Cloud Complex WD

    CERN Document Server

    Peek, J E G; Sana, Hugues; Roman-Duval, Julia; Tumlinson, Jason; Zheng, Yong

    2016-01-01

    We present medium-resolution, near-ultraviolet VLT/FLAMES observations of the star USNO-A0600-15865535. We adapt a standard method of stellar typing to our measurement of the shape of the Balmer epsilon absorption line to demonstrates that USNO-A0600-15865535 is a blue horizontal branch star, residing in the lower stellar halo at a distance of 4.4 kpc from the Sun. We measure the H & K lines of singly-ionized calcium and find two isolated velocity components, one originating in the disk, and one associated with high-velocity cloud complex WD. This detection demonstrated that complex WD is closer than ~4.4 kpc and is the first distance constraint on the +100 km/s Galactic complex of clouds. We find that Complex WD is not in corotation with the Galactic disk as has been assumed for decades. We examine a number of scenarios, and find that the most likely is that Complex WD was ejected from the solar neighborhood and is only a few kpc from the Sun.

  1. Introducing Complex Decision Models to the Decision Maker with Computer Software - The Profile Distance Method (PDM

    Directory of Open Access Journals (Sweden)

    Edward Bernroider

    2010-06-01

    Full Text Available In this paper we demonstrate how the profile distance method was transformed into a software environment enabling the decision maker to utilize a complex decision making tool without any advanced knowledge of the underlying mathematical and technical features. We present theoretical and technical aspects as well as contextual and usage related information from the viewpoint of the decision maker. Preliminary empirical results suggest that the developed software component is effective in terms of platform independence, usability and intuitive interface design. The data showed a good rating for usefulness, which, however, was targeted as the main goal for further development.

  2. A Tractable Complex Network Model Based onthe Stochastic Mean-Field Model of Distance

    Science.gov (United States)

    Aldous, David J.

    Much recent research activity has been devoted to empirical study and theoretical models of complex networks (random graphs) possessing three qualitative features: power-law degree distributions, local clustering, and slowly-growing diameter. We point out a new (in this context) platform for such models - the stochastic mean-field model of distances - and within this platform study a simple two-parameter proportional attachment (or copying) model. The model is mathematically natural, permits a wide variety of explicit calculations, has the desired three qualitative features, and fits the complete range of degree scaling exponents and clustering parameters; in these respects it compares favorably with existing models.

  3. AN ENGLISH-AMHARIC DICTIONARY OF EVERYDAY USAGE, PART II, (L-Z).

    Science.gov (United States)

    LESLAU, WOLF

    THIS VOLUME, (L-Z), COMPRISES THE SECOND HALF OF THE FIRST MODERN ENGLISH-AMHARIC DICTIONARY. THIS TWO-PART DICTIONARY HAS BEEN PREPARED FOR THE STUDENT FAMILIAR WITH THE SCRIPT AND GRAMMAR OF AMHARIC, THE NATIONAL LANGUAGE OF ETHIOPIA. THE SELECTIONS, LIMITED IN SCOPE, ARE BASED ON EDUCATED COLLOQUIAL AND ARE PRESENTED IN CONTEXTUAL SENTENCES.…

  4. Reflectance measurements of PTFE, Kapton, and PEEK for xenon scintillation light for the LZ detector.

    Science.gov (United States)

    Arthurs, M.; Batista, E.; Haefner, J.; Lorenzon, W.; Morton, D.; Neff, A.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; LZ Collaboration

    2017-01-01

    LZ (LUX-Zeplin) is an international collaboration that will look for dark matter candidates, WIMPs (Weakly Interacting Massive Particles), through direct detection by dual-phase time projection chamber (TPC) using liquid xenon. The LZ detector will be located nearly a mile underground at SURF, South Dakota, shielded from cosmic background radiation. Seven tons active mass of liquid xenon will be used for detecting the weak interaction of WIMPs with ordinary matter. Over three years of operation it is expected to reach the ultimate sensitivity of 2x10-48 cm2 for a WIMP mass of 50 GeV. As for many other rare event searches, high light collection efficiency is essential for LZ detector. Moreover, in order to achieve greater active volume for detection as well as reduce potential backgrounds, thinner detector walls without significant loss in reflectance are desired. Reflectance measurements of polytetrafluoroethylene (PTFE), Kapton, and PEEK for xenon scintillation light (178 nm), conducted at the University of Michigan using the Michigan Xenon Detector (MiX) will be presented. The University of Michigan, LZ Collaboration, The US Department of Energy.

  5. Examining Motivation in Online Distance Learning Environments: Complex, Multifaceted, and Situation-Dependent

    Directory of Open Access Journals (Sweden)

    Maggie Hartnett

    2011-10-01

    Full Text Available Existing research into motivation in online environments has tended to use one of two approaches. The first adopts a trait-like model that views motivation as a relatively stable, personal characteristic of the learner. Research from this perspective has contributed to the notion that online learners are, on the whole, intrinsically motivated. The alternative view concentrates on the design of online learning environments to encourage optimal learner motivation. Neither approach acknowledges a contemporary view of motivation that emphasises the situated, mutually constitutive relationship of the learner and the learning environment. Using self-determination theory (SDT as a framework, this paper explores the motivation to learn of preservice teachers in two online distance-learning contexts. In this study, learners were found to be not primarily intrinsically motivated. Instead, student motivation was found to be complex, multifaceted, and sensitive to situational conditions.

  6. LZ50钢在超高周疲劳条件下Coaxing效应的研究%Coaxing effect of LZ50 steel under ultrasonic fatigue condition

    Institute of Scientific and Technical Information of China (English)

    周蒙蛟; 王弘

    2014-01-01

    利用超声疲劳试验设备对LZ50钢进行变幅疲劳性能的研究同时用扫描电子显微镜(SEM)观察分析了疲劳断口的形貌特征。试验采用荷载步线型累加的加载形式,选取最大荷载σhigh为390 MPa。结果表明:经过小荷载作用后的实验材料其疲劳性能有显著增强,表现出明显的Coaxing效应;引入强化因子对Palmgreen-Miner累积损伤准则进行修正,经修正后的Palmgreen-Miner累积损伤准则能较好地预测材料使用工况下的变幅寿命。%Variable amplitude fatigue properties of LZ50 steel were investigated with ultrasonic fatigue testing equipment. Fatigue tests were performed with a linear step accumulative loading. The maximum stress was selected at 390 MPa. The fracture surfaces of specimens were investigated with scanning electron microscopy(SEM). The experimental results show a marked Coaxing effect. The Palmgreen-Miner damage formula was verified based on the step-loading fatigue experiment result of LZ50 steel. It is indicated that the calculation result of the formula is of higher precision and it approaches the experimental result.

  7. Molecular dynamics simulations of the cardiac troponin complex performed with FRET distances as restraints.

    Directory of Open Access Journals (Sweden)

    Jayant James Jayasundar

    Full Text Available Cardiac troponin (cTn is the Ca(2+-sensitive molecular switch that controls cardiac muscle activation and relaxation. However, the molecular detail of the switching mechanism and how the Ca(2+ signal received at cardiac troponin C (cTnC is communicated to cardiac troponin I (cTnI are still elusive. To unravel the structural details of troponin switching, we performed ensemble Förster resonance energy transfer (FRET measurements and molecular dynamic (MD simulations of the cardiac troponin core domain complex. The distance distributions of forty five inter-residue pairs were obtained under Ca(2+-free and saturating Ca(2+ conditions from time-resolved FRET measurements. These distances were incorporated as restraints during the MD simulations of the cardiac troponin core domain. Compared to the Ca(2+-saturated structure, the absence of regulatory Ca(2+ perturbed the cTnC N-domain hydrophobic pocket which assumed a closed conformation. This event partially unfolded the cTnI regulatory region/switch. The absence of Ca(2+, induced flexibility to the D/E linker and the cTnI inhibitory region, and rotated the cTnC N-domain with respect to rest of the troponin core domain. In the presence of saturating Ca(2+ the above said phenomenon were absent. We postulate that the secondary structure perturbations experienced by the cTnI regulatory region held within the cTnC N-domain hydrophobic pocket, coupled with the rotation of the cTnC N-domain would control the cTnI mobile domain interaction with actin. Concomitantly the rotation of the cTnC N-domain and perturbation of the D/E linker rigidity would control the cTnI inhibitory region interaction with actin to effect muscle relaxation.

  8. Study of LZ-Based Location Prediction and Its Application to Transportation Recommender Systems

    Directory of Open Access Journals (Sweden)

    Patricia Noriega-Vivas

    2012-06-01

    Full Text Available Predicting users’ next location allows to anticipate their future context, thus providing additional time to be ready for that context and react consequently. This work is focused on a set of LZ-based algorithms (LZ, LeZi Update and Active LeZi capable of learning mobility patterns and estimating the next location with low resource needs, which makes it possible to execute them on mobile devices. The original algorithms have been divided into two phases, thus being possible to mix them and check which combination is the best one to obtain better prediction accuracy or lower resource consumption. To make such comparisons, a set of GSM-based mobility traces of 95 different users is considered. Finally, a prototype for mobile devices that integrates the predictors in a public transportation recommender system is described in order to show an example of how to take advantage of location prediction in an ubiquitous computing environment.

  9. PROBABILISTIC MODELS FOR LONG FATIGUE CRACK GROWTH RATES OF LZ50 AXLE STEEL

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yong-xiang; HE Chao-ming; YANG Bing; HUANG Yu-zhong; GAO Qing; WU Ping-bo

    2005-01-01

    Experimental study is performed on the probabilistic models for the long fatigue crack growth rates (da/dN) of LZ50 axle steel. An equation for crack growth rate was derived to consider the trend of stress intensity factor range going down to the threshold and the average stress effect. The probabilistic models were presented on the equation. They consist of the probabilistic da/dN-△K relations, the confidence-based da/dN-△K relations, and the probabilistic- and confidence-based da/dN-△K relations.Efforts were made respectively to characterize the effects of probabilistic assessments due to the scattering regularity of test data, the number of sampling, and both of them.These relations can provide wide selections for practice. Analysis on the test data of LZ50 steel indicates that the present models are available and feasible.

  10. Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches

    Energy Technology Data Exchange (ETDEWEB)

    Akerib, D.S.; et al.

    2017-02-08

    The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $^{238}$U$_{e}$~$<$1.6~mBq/kg, $^{238}$U$_{l}$~$<$0.09~mBq/kg, $^{232}$Th$_{e}$~$=0.28\\pm 0.03$~mBq/kg, $^{232}$Th$_{l}$~$=0.25\\pm 0.02$~mBq/kg, $^{40}$K~$<$0.54~mBq/kg, and $^{60}$Co~$<$0.02~mBq/kg (68\\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $0.160\\pm0.001$(stat)$\\pm0.030$(sys) counts.

  11. The NMR solution structure of a mutant of the Max b/HLH/LZ free of DNA: insights into the specific and reversible DNA binding mechanism of dimeric transcription factors.

    Science.gov (United States)

    Sauvé, Simon; Tremblay, Luc; Lavigne, Pierre

    2004-09-17

    Basic region-helix1-loop-helix2-leucine zipper (b/H(1)LH(2)/LZ) transcription factors bind specific DNA sequence in their target gene promoters as dimers. Max, a b/H(1)LH(2)/LZ transcription factor, is the obligate heterodimeric partner of the related b/H(1)LH(2)/LZ proteins of the Myc and Mad families. These heterodimers specifically bind E-box DNA sequence (CACGTG) to activate (e.g. c-Myc/Max) and repress (e.g. Mad1/Max) transcription. Max can also homodimerize and bind E-box sequences in c-Myc target gene promoters. While the X-ray structure of the Max b/H(1)LH(2)/LZ/DNA complex and that of others have been reported, the precise sequence of events leading to the reversible and specific binding of these important transcription factors is still largely unknown. In order to provide insights into the DNA binding mechanism, we have solved the NMR solution structure of a covalently homodimerized version of a Max b/H(1)LH(2)/LZ protein with two stabilizing mutations in the LZ, and characterized its backbone dynamics from (15)N spin-relaxation measurements in the absence of DNA. Apart from minor differences in the pitch of the LZ, possibly resulting from the mutations in the construct, we observe that the packing of the helices in the H(1)LH(2) domain is almost identical to that of the two crystal structures, indicating that no important conformational change in these helices occurs upon DNA binding. Conversely to the crystal structures of the DNA complexes, the first 14 residues of the basic region are found to be mostly unfolded while the loop is observed to be flexible. This indicates that these domains undergo conformational changes upon DNA binding. On the other hand, we find the last four residues of the basic region form a persistent helical turn contiguous to H(1). In addition, we provide evidence of the existence of internal motions in the backbone of H(1) that are of larger amplitude and longer time-scale (nanoseconds) than the ones in the H(2) and LZ domain

  12. Do you see what we see? The complex effects of perceptual distance between leaders and teams.

    Science.gov (United States)

    Gibson, Cristina B; Cooper, Cecily D; Conger, Jay A

    2009-01-01

    Previous distance-related theories and concepts (e.g., social distance) have failed to address the sometimes wide disparity in perceptions between leaders and the teams they lead. Drawing from the extensive literature on teams, leadership, and cognitive models of social information processing, the authors develop the concept of leader-team perceptual distance, defined as differences between a leader and a team in perceptions of the same social stimulus. The authors investigate the effects of perceptual distance on team performance, operationalizing the construct with 3 distinct foci: goal accomplishment, constructive conflict, and decision-making autonomy. Analyzing leader, member, and customer survey responses for a large sample of teams, the authors demonstrate that perceptual distance between a leader and a team regarding goal accomplishment and constructive conflict have a nonlinear relationship with team performance. Greater perceptual differences are associated with decreases in team performance. Moreover, this effect is strongest when a team's perceptions are more positive than the leader's are (as opposed to the reverse). This pattern illustrates the pervasive effects that perceptions can have on team performance, highlighting the importance of developing awareness of perceptions in order to increase effectiveness. Implications for theory and practice are delineated. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  13. On the computational complexity of degenerate unit distance representations of graphs

    CERN Document Server

    Kratochvil, Jan; Pisanski, Tomaz

    2010-01-01

    Some graphs admit drawings in the Euclidean k-space in such a (natu- ral) way, that edges are represented as line segments of unit length. Such drawings will be called k dimensional unit distance representations. When two non-adjacent vertices are drawn in the same point, we say that the representation is degenerate. The dimension (the Euclidean dimension) of a graph is defined to be the minimum integer k needed that a given graph has non-degenerate k dimensional unit distance representation (with the property that non-adjacent vertices are mapped to points, that are not distance one appart). It is proved that deciding if an input graph is homomorphic to a graph with dimension k >= 2 (with the Euclidean dimension k >= 2) are NP-hard problems.

  14. VUV light reflectivity measurements from PTFE in Liquid Xenon for the LZ Dark Matter experiment

    Science.gov (United States)

    Pushkin, Kirill; LZ Collaboration

    2016-03-01

    The LUX-Zeplin (LZ) collaboration is the next generation of the experiment to search for Dark Matter in the Universe with a dual-phase detector based on liquid xenon (LXe) with a target mass of 7 ton. LXe dual phase detectors are very sensitive probes to search for WIMP dark matter interactions. The LZ collaboration is conducting R&D to study VUV light reflectivity from PTFE (Teflon) in LXe. Teflon is used in dual phase detectors both as an electrical insulator and as reflector of VUV scintillation light (~175 nm) to improve photon detection with photomultiplier tubes (PMTs). However, experimental data for the reflectance of VUV light from PTFE in LXe is not sufficiently conclusive. We present a new technique of measuring the light reflectivity from PTFE by varying the fractional area of the PMT in the detector. PTFE reflectivity measurements were performed as a function of Teflon wall thickness in the range of 2 mm to 9.5 mm. The method, apparatus and experimental results will be presented.

  15. Traveling salesman problems with PageRank Distance on complex networks reveal community structure

    Science.gov (United States)

    Jiang, Zhongzhou; Liu, Jing; Wang, Shuai

    2016-12-01

    In this paper, we propose a new algorithm for community detection problems (CDPs) based on traveling salesman problems (TSPs), labeled as TSP-CDA. Since TSPs need to find a tour with minimum cost, cities close to each other are usually clustered in the tour. This inspired us to model CDPs as TSPs by taking each vertex as a city. Then, in the final tour, the vertices in the same community tend to cluster together, and the community structure can be obtained by cutting the tour into a couple of paths. There are two challenges. The first is to define a suitable distance between each pair of vertices which can reflect the probability that they belong to the same community. The second is to design a suitable strategy to cut the final tour into paths which can form communities. In TSP-CDA, we deal with these two challenges by defining a PageRank Distance and an automatic threshold-based cutting strategy. The PageRank Distance is designed with the intrinsic properties of CDPs in mind, and can be calculated efficiently. In the experiments, benchmark networks with 1000-10,000 nodes and varying structures are used to test the performance of TSP-CDA. A comparison is also made between TSP-CDA and two well-established community detection algorithms. The results show that TSP-CDA can find accurate community structure efficiently and outperforms the two existing algorithms.

  16. Constant-Distance Mode Nanospray Desorption Electrospray Ionization Mass Spectrometry Imaging of Biological Samples with Complex Topography

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son N.; Liyu, Andrey V.; Chu, Rosalie K.; Anderton, Christopher R.; Laskin, Julia

    2017-01-17

    A new approach for constant distance mode mass spectrometry imaging of biological samples using nanospray desorption electrospray ionization (nano-DESI MSI) was developed by integrating a shear-force probe with nano-DESI probe. The technical concept and basic instrumental setup as well as general operation of the system are described. Mechanical dampening of resonant oscillations due to the presence of shear forces between the probe and the sample surface enables constant-distance imaging mode via a computer controlled closed feedback loop. The capability of simultaneous chemical and topographic imaging of complex biological samples is demonstrated using living Bacillus Subtilis ATCC 49760 colonies on agar plates. The constant-distance mode nano-DESI MSI enabled imaging of many metabolites including non-ribosomal peptides (surfactin, plipastatin and iturin) and iron-bound heme on the surface of living bacterial colonies ranging in diameter from 10 mm to 13 mm with height variations of up to 0.8 mm above the agar plate. Co-registration of ion images to topographic images provided higher-contrast images. Constant-mode nano-DESI MSI is ideally suited for imaging biological samples of complex topography in their native state.

  17. Constant-Distance Mode Nanospray Desorption Electrospray Ionization Mass Spectrometry Imaging of Biological Samples with Complex Topography.

    Science.gov (United States)

    Nguyen, Son N; Liyu, Andrey V; Chu, Rosalie K; Anderton, Christopher R; Laskin, Julia

    2017-01-17

    A new approach for constant-distance mode mass spectrometry imaging (MSI) of biological samples using nanospray desorption electrospray ionization (nano-DESI) was developed by integrating a shear-force probe with the nano-DESI probe. The technical concept and basic instrumental setup, as well as the general operation of the system are described. Mechanical dampening of resonant oscillations due to the presence of shear forces between the probe and the sample surface enabled the constant-distance imaging mode via a computer-controlled closed-feedback loop. The capability of simultaneous chemical and topographic imaging of complex biological samples is demonstrated using living Bacillus subtilis ATCC 49760 colonies on agar plates. The constant-distance mode nano-DESI MSI enabled imaging of many metabolites, including nonribosomal peptides (surfactin, plipastatin, and iturin) on the surface of living bacterial colonies, ranging in diameter from 10 to 13 mm, with height variations up to 0.8 mm above the agar plate. Co-registration of ion images to topographic images provided higher-contrast images. Based on this effort, constant-mode nano-DESI MSI proved to be ideally suited for imaging biological samples of complex topography in their native states.

  18. The Indirect Perception of Distance: Interpretive Complexities in Berkeley's Theory of Vision

    Directory of Open Access Journals (Sweden)

    Michael James Braund

    2007-12-01

    Full Text Available The problem of whether perception is direct or if it depends on additional, cognitive contributions made by the perceiving subject, is posed with particular force in an Essay towards a New Theory of Vision (NTV. It is evident from the recurrent treatment it receives therein that Berkeley considers it to be one of the central issues concerning perception. Fittingly, the NTV devotes the most attention to it. In this essay, I deal exclusively with Berkeley's treatment of the problem of indirect distance perception, as it is presented in the context of that work.

  19. Reishi Protein LZ-8 Induces FOXP3(+) Treg Expansion via a CD45-Dependent Signaling Pathway and Alleviates Acute Intestinal Inflammation in Mice.

    Science.gov (United States)

    Hsu, Hsien-Yeh; Kuan, Yen-Chou; Lin, Tung-Yi; Tsao, Shu-Ming; Hsu, Jason; Ma, Li-Juan; Sheu, Fuu

    2013-01-01

    LZ-8, an immunomodulatory protein isolated from Ganoderma lucidum (also known as Ling-Zhi or Reishi), has been shown to promote cell proliferation and IL-2 production in T cells. In this study, we show that LZ-8 induces the expansion of both murine and human CD4(+) T cells into FOXP3(+) regulatory T (Treg) cells. LZ-8 treatment was found to stimulate a 4-fold and a 10-fold expansion in the Treg populations of murine and human primary CD4(+) T cells, respectively. In addition, the expression of CTLA-4 and IL-10 was induced in LZ-8-treated CD4(+) T cells. Using neutralizing antibodies and gene-deficient T-cell lines, we also found that LZ-8 promotes Treg expansion through a CD45-mediated signaling pathway and that the CD18-dependent induction of IL-2 was involved in Treg formation and IL-10 production. The suppressive activity of LZ-8 was confirmed using a murine model of DSS-induced colitis; the disease was alleviated by the adoptive transfer of LZ-8-treated CD4(+) T cells. In conclusion, a new regulatory function for LZ-8 was identified, and the molecular mechanisms underlying this function were elucidated.

  20. Reishi Protein LZ-8 Induces FOXP3+ Treg Expansion via a CD45-Dependent Signaling Pathway and Alleviates Acute Intestinal Inflammation in Mice

    Directory of Open Access Journals (Sweden)

    Hsien-Yeh Hsu

    2013-01-01

    Full Text Available LZ-8, an immunomodulatory protein isolated from Ganoderma lucidum (also known as Ling-Zhi or Reishi, has been shown to promote cell proliferation and IL-2 production in T cells. In this study, we show that LZ-8 induces the expansion of both murine and human CD4+ T cells into FOXP3+ regulatory T (Treg cells. LZ-8 treatment was found to stimulate a 4-fold and a 10-fold expansion in the Treg populations of murine and human primary CD4+ T cells, respectively. In addition, the expression of CTLA-4 and IL-10 was induced in LZ-8-treated CD4+ T cells. Using neutralizing antibodies and gene-deficient T-cell lines, we also found that LZ-8 promotes Treg expansion through a CD45-mediated signaling pathway and that the CD18-dependent induction of IL-2 was involved in Treg formation and IL-10 production. The suppressive activity of LZ-8 was confirmed using a murine model of DSS-induced colitis; the disease was alleviated by the adoptive transfer of LZ-8-treated CD4+ T cells. In conclusion, a new regulatory function for LZ-8 was identified, and the molecular mechanisms underlying this function were elucidated.

  1. Dependency Resolution Difficulty Increases with Distance in Persian Separable Complex Predicates: Evidence for Expectation and Memory-Based Accounts.

    Science.gov (United States)

    Safavi, Molood S; Husain, Samar; Vasishth, Shravan

    2016-01-01

    Delaying the appearance of a verb in a noun-verb dependency tends to increase processing difficulty at the verb; one explanation for this locality effect is decay and/or interference of the noun in working memory. Surprisal, an expectation-based account, predicts that delaying the appearance of a verb either renders it no more predictable or more predictable, leading respectively to a prediction of no effect of distance or a facilitation. Recently, Husain et al. (2014) suggested that when the exact identity of the upcoming verb is predictable (strong predictability), increasing argument-verb distance leads to facilitation effects, which is consistent with surprisal; but when the exact identity of the upcoming verb is not predictable (weak predictability), locality effects are seen. We investigated Husain et al.'s proposal using Persian complex predicates (CPs), which consist of a non-verbal element-a noun in the current study-and a verb. In CPs, once the noun has been read, the exact identity of the verb is highly predictable (strong predictability); this was confirmed using a sentence completion study. In two self-paced reading (SPR) and two eye-tracking (ET) experiments, we delayed the appearance of the verb by interposing a relative clause (Experiments 1 and 3) or a long PP (Experiments 2 and 4). We also included a simple Noun-Verb predicate configuration with the same distance manipulation; here, the exact identity of the verb was not predictable (weak predictability). Thus, the design crossed Predictability Strength and Distance. We found that, consistent with surprisal, the verb in the strong predictability conditions was read faster than in the weak predictability conditions. Furthermore, greater verb-argument distance led to slower reading times; strong predictability did not neutralize or attenuate the locality effects. As regards the effect of distance on dependency resolution difficulty, these four experiments present evidence in favor of working memory

  2. Distance metric learning for complex networks: Towards size-independent comparison of network structures

    Science.gov (United States)

    Aliakbary, Sadegh; Motallebi, Sadegh; Rashidian, Sina; Habibi, Jafar; Movaghar, Ali

    2015-02-01

    Real networks show nontrivial topological properties such as community structure and long-tail degree distribution. Moreover, many network analysis applications are based on topological comparison of complex networks. Classification and clustering of networks, model selection, and anomaly detection are just some applications of network comparison. In these applications, an effective similarity metric is needed which, given two complex networks of possibly different sizes, evaluates the amount of similarity between the structural features of the two networks. Traditional graph comparison approaches, such as isomorphism-based methods, are not only too time consuming but also inappropriate to compare networks with different sizes. In this paper, we propose an intelligent method based on the genetic algorithms for integrating, selecting, and weighting the network features in order to develop an effective similarity measure for complex networks. The proposed similarity metric outperforms state of the art methods with respect to different evaluation criteria.

  3. Biodegradation of the Herbicide 2,4-Dichlorophenoxyacetic Acid by a New Isolated Strain of Achromobacter sp. LZ35.

    Science.gov (United States)

    Xia, Zhen-Yuan; Zhang, Long; Zhao, Yan; Yan, Xin; Li, Shun-Peng; Gu, Tao; Jiang, Jian-Dong

    2017-02-01

    In this study, a bacterial strain of Achromobacter sp. LZ35, which was capable of utilizing 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxy acetic acid (MCPA) as the sole sources of carbon and energy for growth, was isolated from the soil in a disused pesticide factory in Suzhou, China. The optimal 2,4-D degradation by strain LZ35 occurred at 30 °C and pH 8.0 when the initial 2,4-D concentration was 200 mg L(-1). Strain LZ35 harbored the conserved 2,4-D/alpha-ketoglutarate dioxygenase (96%) and 2,4-dichlorophenol hydroxylase (99%), and catabolized 2,4-D via the intermediate 2,4-dichlorophenol. The inoculation of 7.8 × 10(6) CFU g(-1) soil of strain LZ35 cells to 2,4-D-contaminated soil could efficiently remove over 75 and 90% of 100 and 50 mg L(-1) 2,4-D in 12 days and significantly released the phytotoxicity of maize caused by the 2,4-D residue. This is the first report of an Achromobacter sp. strain that was capable of mineralizing both 2,4-D and MCPA. This study provides us a promising candidate for its application in the bioremediation of 2,4-D- or MCPA-contaminated sites.

  4. Complete genome sequence of Lactobacillus plantarum LZ227, a potential probiotic strain producing B-group vitamins.

    Science.gov (United States)

    Li, Ping; Zhou, Qingqing; Gu, Qing

    2016-09-20

    B-group vitamins play an important role in human metabolism, whose deficiencies are associated with a variety of disorders and diseases. Certain microorganisms such as Lactic acid bacteria (LAB) have been shown to have capacities for B-group vitamin production and thus could potentially replace chemically synthesized vitamins for food fortification. A potential probiotic strain named Lactobacillus plantarum LZ227, which was isolated from raw cow milk in this study, exhibits the ability to produce B-group vitamins. Complete genome sequencing of LZ227 was performed to gain insights into the genetic elements involved in B-group vitamin production. The genome of LZ227 contains a circular 3,131,750-bp chromosome, three circular plasmids and two predicted linear plasmids. LZ227 also contains gene clusters for biosynthesis of both riboflavin and folate. This genome sequence provides a basis for further elucidation of its molecular genetics and probiotic functions, and will facilitate its applications as starter cultures in food industry.

  5. Information Distance

    CERN Document Server

    Bennett, Charles H; Li, Ming; Vitanyi, Paul M B; Zurek, Wojciech H

    2010-01-01

    While Kolmogorov complexity is the accepted absolute measure of information content in an individual finite object, a similarly absolute notion is needed for the information distance between two individual objects, for example, two pictures. We give several natural definitions of a universal information metric, based on length of shortest programs for either ordinary computations or reversible (dissipationless) computations. It turns out that these definitions are equivalent up to an additive logarithmic term. We show that the information distance is a universal cognitive similarity distance. We investigate the maximal correlation of the shortest programs involved, the maximal uncorrelation of programs (a generalization of the Slepian-Wolf theorem of classical information theory), and the density properties of the discrete metric spaces induced by the information distances. A related distance measures the amount of nonreversibility of a computation. Using the physical theory of reversible computation, we give...

  6. Solution structure investigation of Ru(II) complex ion pairs: quantitative NOE measurements and determination of average interionic distances.

    Science.gov (United States)

    Zuccaccia, C; Bellachioma, G; Cardaci, G; Macchioni, A

    2001-11-07

    The structure of the Ru(II) ion pairs trans-[Ru(COMe)[(pz(2))CH(2)](CO)(PMe(3))(2)]X (X(-) = BPh(4)(-), 1a; BPh(3)Me(-), 1b; BPh(3)(n-Bu)(-), 1c; BPh(3)(n-Hex)(-), 1d; B(3, 5-(CF(3))(2)(C(6)H(3)))(4)(-), 1e; PF(6)(-), 1f; and BF(4)(-), 1g; pz = pyrazol-1-yl-ring) was investigated in solution from both a qualitative (chloroform-d, methylene chloride-d(2), nithromethane-d(3)) and quantitative (methylene chloride-d(2)) point of view by performing 1D- and 2D-NOE NMR experiments. In particular, the relative anion-cation localization (interionic structure) was qualitatively determined by (1)H-NOESY and (19)F, (1)H-HOESY (heteronuclear Overhauser effect spectroscopy) NMR experiments. The counteranion locates close to the peripheral protons of the bispyrazolyl ligand independent of its nature and that of the solvent. In complexes 1c and 1d bearing unsymmetrical counteranions, the aliphatic chain points away from the metal center as indicated by the absence of NOE between the terminal Me group and any cationic protons. An estimation of the average interionic distances in solution was obtained by the quantification of the NOE build-up versus the mixing time under the assumption that the interionic and intramolecular correlation times (tau(c)) are the same. Such an assumption was checked by the experimental measurements of tau(c) from both the dipolar contribution to the carbon-13 longitudinal relaxation time T(DD-1)and the comparison of the intramolecular and interionic cross relaxation rate constant (sigma) dependence on the temperature. Both the methodologies indicate that anion and cation have comparable tau(c) values. The determined correlation time values were compared with those obtained for the neutral trans-[Ru(COMe)[(pz(2))BH(2)](CO)(PMe(3))(2)] complex (2), isosteric with the cation of 1. They were significantly shorter (approximately 3.8 times), indicating that the main contribution to dipolar relaxation processes comes from the overall ion pair rotation. As a

  7. Monophyly, distance and character-based multigene barcoding reveal extraordinary cryptic diversity in Nassarius: a complex and dangerous community.

    Directory of Open Access Journals (Sweden)

    Shanmei Zou

    Full Text Available BACKGROUND: Correct identification and cryptic biodiversity revelation for marine organisms are pressing since the marine life is important in maintaining the balance of ecological system and is facing the problem of biodiversity crisis or food safety. DNA barcoding has been proved successful to provide resolution beyond the boundaries of morphological information. Nassarius, the common mudsnail, plays an important role in marine environment and has problem in food safety, but the classification of it is quite confused because of the complex morphological diversity. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a comprehensive barcoding analysis of 22 Nassarius species. We integrated the mitochondrial and nuclear sequences and the morphological characters to determine 13 Nassarius species studied and reveal four cryptic species and one pair synonyms. Distance, monophyly, and character-based barcoding methods were employed. CONCLUSIONS/SIGNIFICANCE: Such successful identification and unexpected cryptic discovery is significant for Nassarius in food safety and species conversation and remind us to pay more attention to the hidden cryptic biodiversity ignored in marine life. Distance, monophyly, and character-based barcoding methods are all very helpful in identification but the character-based method shows some advantages.

  8. Representing distance, consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    to mobility and its social context. Such an understanding can be approached through representations, as distance is being represented in various ways, most noticeably in maps and through the notions of space and Otherness. The question this talk subsequently asks is whether these representations of distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...... are present in theoretical and empirical elaborations on mobility, but these remain largely implicit and unchallenged (Bauman 1998). This talk will endeavour to unmask distance as a theoretical entity by exploring ways in which distance can be understood and by discussing distance through its representations...

  9. Dynamic Recrystallization Kinetics and Microstructural Evolution for LZ50 Steel During Hot Deformation

    Science.gov (United States)

    Du, Shiwen; Chen, Shuangmei; Song, Jianjun

    2016-09-01

    The dynamic recrystallization (DRX) behavior of LZ50 steel was investigated using hot compression tests at a deformation temperature of 870-1170 °C and a strain rate of 0.05-3 s-1. The effects of deformation temperature, strain, strain rate, and initial austenite grain size on the microstructural evolution during DRX were studied in detail. The austenite grain size of DRX was refined with increasing strain rate and decreasing temperature, whereas the initial grain size had no influence on DRX grain size. A model based on the Avrami equation was proposed to estimate the kinetics of the DRX under different deformation conditions. A DRX map, which was derived from the DRX kinetics, the recrystallized microstructure, and the flow stress analysis, can be used to identify optimal deformation conditions. The initiation of DRX was lower than Z c (critical Zener-Hollomon parameter) and higher than ɛc (critical strain). The relationship between the DRX microstructure and the Z parameter was analyzed. Fine DRX grain sizes can be achieved with a moderate Z value, which can be used to identify suitable deformation parameters.

  10. [A totally implantable hearing aid for inner ear deafness: TICA LZ 3001].

    Science.gov (United States)

    Leysieffer, H; Baumann, J W; Mayer, R; Müller, D; Müller, G; Schön, T; Volz, A; Zenner, H P

    1998-10-01

    Recently, Zenner et al. implanted the first totally implantable electronic hearing devices in patients with SNHL (HNO 46 [1998] 844-852). In the present report, technical and audiological features of the implant TICA are published. The development of the piezoelectric transducer and the microphone for implantation in the posterior wall of the auditory canal as components for the present fully implantable hearing system has already been described (HNO 45, 1997, 792-880). Here we report about our experience with the electronic main module that completes the TICA LZ 3001 system. This module is suited for implantation in the mastoid bone and contains the signal-processing electronics and an integrated battery that can be recharged transcutaneously with a portable charger. The recharging time is around 2 h for an implant operating time of 50 h. The microphone and transducer connectors allow for easy replacement of the main module when the battery lifetime is reached. This lifetime is around 3-5 years. A small wireless remote control allows volume adjustment, contains an on/off switch, and permits selection of four different individual hearing programs. The basic audiological features are provided by a flexible, digitally programmable 3-channel-AGC-system with a peak clipping function. The total bandwidth is around 10 kHz. To our knowledge this is the first fully implantable hearing system that has been in implanted in humans.

  11. Hot Deformation Behavior and Dynamic Recrystallization of Medium Carbon LZ50 Steel

    Science.gov (United States)

    Du, Shiwen; Chen, Shuangmei; Song, Jianjun; Li, Yongtang

    2017-01-01

    Hot deformation and dynamic recrystallization behaviors of a medium carbon steel LZ50 were systematically investigated in the temperature range from 1143 K to 1443 K (870 °C to 1170 °C) at strain rates from 0.05 to 3s-1 using a Gleeble-3500 thermo-simulation machine. The flow stress constitutive equation for hot deformation of this steel was developed with the two-stage Laasraoui equation. The activation energy of the tested steel was 304.27 KJ/mol, which was in reasonable agreement with those reported previously. The flow stress of this steel in hot deformation was mainly controlled by dislocation climb during their intragranular motion. The effect of Zener-Hollomon parameter on the characteristic points of the flow curves was studied, and the dependence of critical strain on peak strain obeyed a linear equation. Dynamic recrystallization was the most important softening mechanism for the tested steel during hot deformation. Kinetic equation of this steel was also established based on the flow stress. The austenite grain size of complete dynamic recrystallization was a power law function of Zener-Hollomon parameter with an exponent of -0.2956. Moreover, the microstructures induced under different deformation conditions were analyzed.

  12. Hot Deformation Behavior and Dynamic Recrystallization of Medium Carbon LZ50 Steel

    Science.gov (United States)

    Du, Shiwen; Chen, Shuangmei; Song, Jianjun; Li, Yongtang

    2017-03-01

    Hot deformation and dynamic recrystallization behaviors of a medium carbon steel LZ50 were systematically investigated in the temperature range from 1143 K to 1443 K (870 °C to 1170 °C) at strain rates from 0.05 to 3s-1 using a Gleeble-3500 thermo-simulation machine. The flow stress constitutive equation for hot deformation of this steel was developed with the two-stage Laasraoui equation. The activation energy of the tested steel was 304.27 KJ/mol, which was in reasonable agreement with those reported previously. The flow stress of this steel in hot deformation was mainly controlled by dislocation climb during their intragranular motion. The effect of Zener-Hollomon parameter on the characteristic points of the flow curves was studied, and the dependence of critical strain on peak strain obeyed a linear equation. Dynamic recrystallization was the most important softening mechanism for the tested steel during hot deformation. Kinetic equation of this steel was also established based on the flow stress. The austenite grain size of complete dynamic recrystallization was a power law function of Zener-Hollomon parameter with an exponent of -0.2956. Moreover, the microstructures induced under different deformation conditions were analyzed.

  13. Complete genome sequence of Lactobacillus plantarum LZ206, a potential probiotic strain with antimicrobial activity against food-borne pathogenic microorganisms.

    Science.gov (United States)

    Li, Ping; Gu, Qing; Zhou, Qingqing

    2016-11-20

    Lactobacilli strains have been considered as important candidates for manufacturing "natural food", due to their antimicrobial properties and generally regarded as safe (GRAS) status. Lactobacillus plantarum LZ206 is a potential probiotic strain isolated from raw cow milk, with antimicrobial activity against various pathogens, including Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes), Gram-negtive bacteria (Escherichia coli and Salmonella enterica), and fungus Candida albicans. To better understand molecular base for its antimicrobial activity, entire genome of LZ206 was sequenced. It was revealed that genome of LZ206 contained a circular 3,212,951-bp chromosome, two circular plasmids and one predicted linear plasmid. A plantaricin gene cluster, which is responsible for bacteriocins biosynthesis and could be associated with its broad-spectrum antimicrobial activity, was identified based on comparative genomic analysis. Whole genome sequencing of L. plantarum LZ206 might facilitate its applications to protect food products from pathogens' contamination in the dairy industry.

  14. Polysaccharides PS-G and protein LZ-8 from Reishi (Ganoderma lucidum) exhibit diverse functions in regulating murine macrophages and T lymphocytes.

    Science.gov (United States)

    Yeh, Chen-Hao; Chen, Hsiao-Chin; Yang, Jeng-Je; Chuang, Wen-I; Sheu, Fuu

    2010-08-11

    Bioactive components in Ganoderma lucidum mainly include polysaccharides (PS-G) and immunomodulatory protein Ling Zhi-8 (LZ-8). These components may have diverse regulatory functions in the immune system. However, the PS-G preparations from different procedures still contained partial LZ-8 residue, indicating that the specific target and regulating function of PS-G and LZ-8 were not fully understood. In the present study, PS-G was subjected to 15% TCA for removing proteins and the LZ-8 detection using anti-LZ-8 monoclonal antibodies showed a remarkable 89.7% protein reduction of the deproteinized PS-G (dpPS-G). The Saccharomyces cerevisiae which expressed recombinant LZ-8 protein (rLZ-8) without glycosylation was generated and then compared with dpPS-G in the induction toward murine primary macrophage and T lymphocytic cells. The peritoneal macrophages from TLR4-deficient and wild type mice revealed that TLR4 was a putative receptor of dpPS-G, mediating the TNF-alpha, IL-1beta and IL-12p70 cytokine production and CD86, MHC II expression on macrophages, while rLZ-8 enhanced the production of IL-1beta, IL-12p70, CD86, and MHC II expression by another obscure route. rLZ-8-treated macrophages enhanced the release of IFN-gamma and IL-2 by murine CD4(+) and CD8(+) T cells, whereas dpPS-G treatment did not enhance the release of IFN-gamma and IL-2. Furthermore, although the direct rLZ-8-treatment conduced dramatic CD154, CD44 expression on CD3(+) T cells and increased IL-2, IFN-gamma secretion on CD4(+) and CD8(+) T cells, the dpPS-G was incapable of priming CD3(+), CD4(+) or CD8(+) T cells unitarily. Taken together, these results demonstrated that LZ-8 could activate murine macrophages and T lymphocytes but PS-G was merely the activator for macrophages, suggesting their diverse roles in activating the innate and adaptive immunity.

  15. Administration of recombinant Reishi immunomodulatory protein (rLZ-8) diet enhances innate immune responses and elicits protection against nervous necrosis virus in grouper Epinephelus coioides.

    Science.gov (United States)

    Kuan, Yen-Chou; Sheu, Fuu; Lee, Guo-Chi; Tsai, Ming-Wei; Hung, Chih-Liang; Nan, Fan-Hua

    2012-06-01

    Nervous necrosis virus (NNV) infection during larvae and juvenile stage in grouper (Epinephelus coioides) has caused severe economic losses in the aquaculture industry in Asia. The aims of this study were to evaluate the influence of recombinant Reishi protein, rLZ-8, on the innate immune responses and the viral resisting ability in fish. Groupers were fed with rLZ-8 supplemented diet (1.25-37.5 mg (rLZ-8)/kg(diet)), and the cytokine gene expression, innate immune responses, and survival rate after NNV challenge were examined. The fish fed with rLZ-8 diet showed 6- to 11-fold upregulated TNF-α and IL-1β gene expression, along with significant increased respiratory burst and phagocytic activity. Moreover, feeding the fish with 37.5 mg/kg rLZ-8 diet elicited significant improvement in post viral challenge survival rate (85.7%). These discoveries indicated that rLZ-8 could be utilized as an ant-pathogen immunostimulant, and provided a new candidate to fight against NNV infection in fish.

  16. The distance to two neutral hydrogen clouds : The high-velocity complex A and the low-latitude intermediate-velocity cloud

    NARCIS (Netherlands)

    Wakker, B; Howk, C; Schwarz, U; vanWoerden, H; Beers, T; Wilhelm, R; Kalberla, P; Danly, L

    1996-01-01

    A lower limit to the distance of the high-velocity cloud (HVC) complex A of 4 kpc (z > 3 kpc) is derived. The HVC is detected toward the Seyfert galaxy Mrk 106 in Mg II lambda lambda 2796, 2803 absorption spectra taken with Hubble Space Telescope (HST) proving that Mg+ is present in the cloud. It is

  17. Multi-state time-varying reliability evaluation of smart grid with flexible demand resources utilizing Lz transform

    Science.gov (United States)

    Jia, Heping; Jin, Wende; Ding, Yi; Song, Yonghua; Yu, Dezhao

    2017-01-01

    With the expanding proportion of renewable energy generation and development of smart grid technologies, flexible demand resources (FDRs) have been utilized as an approach to accommodating renewable energies. However, multiple uncertainties of FDRs may influence reliable and secure operation of smart grid. Multi-state reliability models for a single FDR and aggregating FDRs have been proposed in this paper with regard to responsive abilities for FDRs and random failures for both FDR devices and information system. The proposed reliability evaluation technique is based on Lz transform method which can formulate time-varying reliability indices. A modified IEEE-RTS has been utilized as an illustration of the proposed technique.

  18. Complete genome sequence of Lactobacillus plantarum LZ95, a potential probiotic strain producing bacteriocins and B-group vitamin riboflavin.

    Science.gov (United States)

    Li, Ping; Gu, Qing

    2016-07-10

    Lactobacillus plantarum LZ95 is a potential probiotic isolated from newborn infant fecal and it is identified to produce riboflavin with great antimicrobial activity. The complete genome sequence of this strain was reported in the present study. The genome contains a 3,261,418-bp chromosome and two plasmids. Genes, related to the biosynthesis of bacteriocins and riboflavin, were identified. This work will facilitate to reveal the biosynthetic mechanism of bacteriocins and B-group vitamins in lactic acid bacteria and provide evidence for its potential application in food industry.

  19. 灵芝免疫调节蛋白(Lz-8)在毕赤酵母中的表达及其免疫活性鉴定%Ganoderma lucidum immunomodulatory protein(Lz-8) expressed in Pichia pastoris and the identification of immunocompetence

    Institute of Scientific and Technical Information of China (English)

    梁重阳; 张淑芹; 刘志屹; 孙非

    2009-01-01

    Fungi immunoregulatory proteins family is effective in immunological regulation and anti-tumor. We used Pichia pastoris expression system for recombinant expression of Lz-8, an immunomodulatory protein isolated from fruiting body of Ganoderma lucidum. The Gs115 (mut+) strains of P. Pastoris was used as host cells. PCR and sequencing of DNA showed that Lz-8 cDNA was successfully integrated into the P. Pastoris genome. Electrophoresis(SDS-PAGE), matrix assisted laser desorption ionisation time-of-flight mass spectrometry(MALDI-TOF-MS) and immunological techniques were used to identify recombinant Lz-8 (rLz-8). Lz-8 expressed in Escherichia coli, the Pichia system requires further optimization to obtain more active fungi immunomodulatory protein. Lz-8 was expressed in P. Pastoris successfully, and polyacrylamide gel electrophoresis in the presence of SDS-PAGE gave a single band with an apparent Mr=14 000 D. MALDI-TOF-MS also showed that molecular weight of rLz-8 was 12 722 D. Aggregation was observed from sheep red blood cells in the presence of purified rLz-8 within the concentration range of 12.5-50 μg/mL. However, no aggregation was seen at concentration greater than 50 μg/mL for any type of human red blood cell.dose at 0.5 mg/kg of rLz-8 induced macrophage cytophagocytesis, and set interferon as control at 0.5 mg/kg. These results suggested that active and stable rLz-8 was obtained in P. Pastoris expression system.%真菌免疫调节蛋白家族(Fungi immunoregulacory proteins,FIPs)各成员所具有的免疫调节和抗肿瘤活性已被广泛研究.本研究利用毕赤酵母表达系统对其成员Lz-8进行了重组表达.以毕赤酵母突变株GS115为表达宿主细胞,PCR和DNA测序结果均显示Lz-8的cDNA已被成功地整合入酵母基因组.聚丙烯酰胺凝胶电泳(SDS-PAGE)、激光解析飞行时间质谱(MALDI-TOF-MS)和免疫学实验均被用于重组表达蛋白的检测.实验结果表明Lz-8在毕赤酵母表达系

  20. Isolation of a facultative anaerobic exoelectrogenic strain LZ-1 and probing electron transfer mechanism in situ by linking UV/Vis spectroscopy and electrochemistry.

    Science.gov (United States)

    Zhou, Lei; Deng, Dandan; Zhang, Yichi; Zhou, Wen; Jiang, Yujing; Liu, Ying

    2017-04-15

    A new facultative anaerobic exoelectrogenic strain LZ-1, belonging to Citrobacter freundii, has been isolated. This strain can produce current densities of 843.9 and 865.6μAcm(-2) using citrate or acetate as carbon source in a three-electrode configuration. The electricity generation performance was also analyzed in a dual-chamber MFC system, reaching a maximum power density of 1233mWm(-2). In addition to acetate and citrate, other carbon sources such as pyruvate, formate, acetate, citrate and fumarate could also be utilized to produce current by strain LZ-1. Data supports the presence of electroactive c-type cytochromes in C. freundii sp. when grown on ITO electrodes, by linking spectroscopy and electrochemistry in situ. Since facultative strains possess many desirable properties compared to anaerobic strains, strain LZ-1 represents a promising exoelectrogenic species in engineering of biological catalysts for microbial electrochemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Normalized information distance

    NARCIS (Netherlands)

    Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.; Emmert-Streib, F.; Dehmer, M.

    2009-01-01

    The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string

  2. Normalized information distance

    NARCIS (Netherlands)

    Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.

    2008-01-01

    The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string

  3. A Comparison of Eye-Health Nutrients, Lutein (L)/Zeaxanthin (Z) Intakes and L/Z Rich Food Choices between College Students Living in Los Angeles and Taiwan

    Science.gov (United States)

    Wang, Li Hui; Tam, Chick F.; Yang, Hsin Ling; Chen, Yin Chang; Davis, Rebecca; Schwartz, Miriam E.

    2008-01-01

    Lutein and zeaxanthin (L/Z) were related to macular health. With respect to increasing life expectancy, age-related macular disease (AMD) has become a concern on public health. The objective was to investigate dietary L/Z intake and its related food preference in populations living in different areas. A three-day dietary record and a supplement…

  4. Comment on 'Interpretation of the Lempel-Ziv Complexity Measure in the context of Biomedical Signal Analysis'

    CERN Document Server

    Balasubramanian, Karthi

    2013-01-01

    In this Communication, we express our reservations on some aspects of the interpretation of the Lempel-Ziv Complexity measure (LZ) by Mateo et al. in "Interpretation of the Lempel-Ziv complexity measure in the context of biomedical signal analysis," IEEE Trans. Biomed. Eng., vol. 53, no. 11, pp. 2282-2288, Nov. 2006. In particular, we comment on the dependence of the LZ complexity measure on number of harmonics, frequency content and amplitude modulation. We disagree with the following statements made by Mateo et al. 1. "LZ is not sensitive to the number of harmonics in periodic signals." 2. "LZ increases as the frequency of a sinusoid increases." 3. "Amplitude modulation of a signal doesnot result in an increase in LZ." We show the dependence of LZ complexity measure on harmonics and amplitude modulation by using a modified version of the synthetic signal that has been used in the original paper. Also, the second statement is a generic statement which is not entirely true. This is true only in the low freque...

  5. Cuevaenes C–E: Three new triene carboxylic derivatives from Streptomyces sp. LZ35ΔgdmAI

    Directory of Open Access Journals (Sweden)

    Jing-Jing Deng

    2014-04-01

    Full Text Available Two pairs of geometrical isomers – cuevaenes A (1 and C (3 as well as cuevaenes D (4 and E (5 – and cuevaene B (2 were isolated from gdmAI-disrupted Streptomyces sp. LZ35. The constitution of cuevaene C (3 was found to be identical to cuevaene A (1 by means of NMR spectroscopy and high resolution mass spectrometry. However, the relative configurations of the triene side chain moieties were determined to be different. It was established on the basis of spectroscopic data that cuevaenes D (4 and E (5 are amides and geometrical isomers. Cuevaenes A–C (1–3 displayed moderate activity against Gram-positive bacteria (e.g., Bacillus subtilis strain ATCC 11060 and modest activity against fungi (e.g., Fusarium verticillioides strain S68 and Rhizoctonia solani strain GXE4. However, cuevaenes D (4 and E (5 showed no inhibitory activity against any of the tested microbes.

  6. Performance Analysis of the Anchor-free Localization Algorithm with Low-Complexity Method for Node Distance Estimation Enhancement Using ToA

    Directory of Open Access Journals (Sweden)

    CIPOV Vladimír

    2013-05-01

    Full Text Available The Ultra Wide-Band (UWB communication technology is used in ToA and these systems are capable resolving individual multipath components in the received Channel Impulse Response and determining their time of their arrival very precisely. In this article the anchor-free localization algorithm using ToA node distance estimation technique is introduced. We propose a low-complexity method for mitigation of the Undetected Direct Path effect which causes considerable errors in the node distance estimation. The method is based on combination of the time delay differences of the reflected paths detected in the measured channel power delay profile, overall channel impulse response length and Mean Excess Delay calculated relative to the firstdetected path.

  7. Species delimitation of the Cycas segmentifida complex (Cycadaceae resolved by phylogenetic and distance analyses of molecular data

    Directory of Open Access Journals (Sweden)

    Xiuyan eFeng

    2016-02-01

    Full Text Available The Cycas segmentifida complex consists of eight species whose distributions overlap in a narrow region in Southwest China. These eight taxa are also morphologically similar and are difficult to be distinguished. Consequently, their taxonomic status has been a matter of discussion in recent years. To study this species complex, we sequenced four plastid intergenic spacers (cpDNA, three nuclear genes and genotyped 12 microsatellites for the eight taxa from 19 different localities. DNA sequences were analyzed using Maximum Likelihood (ML method and Bayesian Inference (BI, and microsatellites were analyzed using the Neighbor-joining (NJ and structure inference methods. Results of cpDNA, nuclear gene GTP and microsatellites all rejected the hypotheses that this complex consisted of eight taxa or one distinct lineages (species but two previously described species were adopted: Cycas guizhouensis K. M. Lan et R. F. Zou and Cycas segmentifida D. Y. Wang et C. Y. Deng. Cycas longlinensis H. T. Chang et Y. C. Zhong was included in C. guizhouensis and the other five taxa were included in C. segmentifida. Our species delimitation inferred from molecular data largely corresponds to morphological differentiation. However, the other two nuclear genes were unable to resolve species boundaries for this complex independently. This study offered evidences from different genomes for dealing with the species boundaries and taxonomical treatment of the C. segmentifida complex in an integrated perspective.

  8. Distance Learning

    Science.gov (United States)

    1997-12-01

    A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army’s training and...educational challenges and the benefits of applying Distance Learning techniques. The ASB study panel makes six specific recommendations, the most

  9. Ca2+ dependence of the distance between Cys-98 of troponin C and Cys-133 of troponin I in the ternary troponin complex. Resonance energy transfer measurements.

    Science.gov (United States)

    Tao, T; Gowell, E; Strasburg, G M; Gergely, J; Leavis, P C

    1989-07-11

    We have used resonance energy transfer to study the spatial relationship between Cys-98 of rabbit skeletal troponin C and Cys-133 of rabbit skeletal troponin I in the reconstituted ternary troponin complex. The donor was introduced by labeling either troponin C or troponin I with N-(iodoacetyl)-N'-(5-sulfo-1-naphthyl)ethylenediamine, while the acceptor was introduced by labeling either protein with N-[4-(dimethylamino)phenyl-4'-azophenyl]maleimide. The extent of energy transfer was determined by measuring the quenching of the donor fluorescence decay. The results indicate first that the distance between these two sites is not fixed, suggesting that the protein regions involved possess considerable segmental flexibility. Second, the mean distance between the two sites is dependent on the metal-binding state of troponin C, being 39.1 A when none of the metal-binding sites are occupied, 41.0 A when Mg2+ ions bind at the high-affinity sites, and 35.5 A when Ca2+ ions bind to the low-affinity sites. Neither the magnitude of the distances nor the trend of change with metal ions differs greatly when the locations of the probes are switched or when steady-state fluorometry was used to determine the transfer efficiency. Since the low-affinity sites have been implicated as the physiological triggering sites, our findings suggest that one of the key events in Ca2+ activation of skeletal muscle contraction is a approximately 5-A decrease in the distance between the Cys-98 region of troponin C and the Cys-133 region of troponin I.

  10. Facile concerted proton-electron transfers in a ruthenium terpyridine-4'-carboxylate complex with a long distance between the redox and basic sites.

    Science.gov (United States)

    Manner, Virginia W; Dipasquale, Antonio G; Mayer, James M

    2008-06-11

    We have designed and prepared ruthenium complexes with terpyridine-4'-carboxylate (tpyCOO) ligands, in which there are six bonds between the redox-active Ru and the basic carboxylate. The protonated Ru(II) complex, RuII(dipic)(tpyCOOH) (Ru(II)COOH), is prepared in one-pot from [(p-cymene)RuCl2]2, tpyCOONa, and then sodium pyridine-2,6-dicarboxylate [Na(dipic)]. A crystal structure of the deprotonated Ru(II) complex, Ru(II)COO-, shows a distance of 6.9 A between the metal and basic sites. The Ru(III) complex (Ru(III)COO) has been isolated by one-electron oxidation of Ru(II)COO- with triarylaminium radical cations (NAr3*+). Ru(III)COO has a bond dissociation free energy (BDFE) of 81 +/- 1 kcal mol(-1), from pKa and E1/2 measurements. It oxidizes 2,4,6-tri-tert-butylphenol (BDFE = 77 +/- 1 kcal mol(-1)) by removal of e- and H+ (triple bond H*) to form 2,4,6-tri-tert-butylphenoxyl radical and Ru(II)COOH, with a second-order rate constant of (2.3 0.2) x 10(4) M(-1) s(-1) and a kH/kD of 7.7 1.2. Thermochemical analysis suggests a concerted proton-electron transfer (CPET) mechanism for this reaction, despite the 6.9 A distance between the redox-active Ru and the H+-accepting oxygen. Ru(III)COO also oxidizes the hydroxylamine TEMPOH to the stable free radical TEMPO and xanthene to bixanthyl. These reactions appear to be similar to processes that have been previously termed hydrogen atom transfer.

  11. Modelling multi-protein complexes using PELDOR distance measurements for rigid body minimisation experiments using XPLOR-NIH

    DEFF Research Database (Denmark)

    Hammond, Colin M; Owen-Hughes, Tom; Norman, David G

    2014-01-01

    Crystallographic and NMR approaches have provided a wealth of structural information about protein domains. However, often these domains are found as components of larger multi domain polypeptides or complexes. Orienting domains within such contexts can provide powerful new insight into their fun......Crystallographic and NMR approaches have provided a wealth of structural information about protein domains. However, often these domains are found as components of larger multi domain polypeptides or complexes. Orienting domains within such contexts can provide powerful new insight...... into their function. The combination of site specific spin labelling and Pulsed Electron Double Resonance (PELDOR) provide a means of obtaining structural measurements that can be used to generate models describing how such domains are oriented. Here we describe a pipeline for modelling the location of thio......-reactive nitroxyl spin locations to engineered sties on the histone chaperone Vps75. We then use a combination of experimentally determined measurements and symmetry constraints to model the orientation in which homodimers of Vps75 associate to form homotetramers using the XPLOR-NIH platform. This provides...

  12. Normalized Information Distance

    CERN Document Server

    Vitanyi, Paul M B; Cilibrasi, Rudi L; Li, Ming

    2008-01-01

    The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string representation. Second, for names and abstract concepts, page count statistics from the World Wide Web can be used. These practical realizations of the normalized information distance can then be applied to machine learning tasks, expecially clustering, to perform feature-free and parameter-free data mining. This chapter discusses the theoretical foundations of the normalized information distance and both practical realizations. It presents numerous examples of successful real-world applications based on these distance measures, ranging from bioinformatics to music clustering to machine translation.

  13. Cardiac Aging Detection Using Complexity Measures

    CERN Document Server

    Balasubramanian, Karthi

    2016-01-01

    As we age, our hearts undergo changes which result in reduction in complexity of physiological interactions between different control mechanisms. This results in a potential risk of cardiovascular diseases which are the number one cause of death globally. Since cardiac signals are nonstationary and nonlinear in nature, complexity measures are better suited to handle such data. In this study, non-invasive methods for detection of cardiac aging using complexity measures are explored. Lempel-Ziv (LZ) complexity, Approximate Entropy (ApEn) and Effort-to-Compress (ETC) measures are used to differentiate between healthy young and old subjects using heartbeat interval data. We show that both LZ and ETC complexity measures are able to differentiate between young and old subjects with only 10 data samples while ApEn requires at least 15 data samples.

  14. All three subunits of RecBCD enzyme are essential for DNA repair and low-temperature growth in the Antarctic Pseudomonas syringae Lz4W.

    Directory of Open Access Journals (Sweden)

    Theetha L Pavankumar

    Full Text Available BACKGROUND: The recD mutants of the Antarctic Pseudomonas syringae Lz4W are sensitive to DNA-damaging agents and fail to grow at 4 degrees C. Generally, RecD associates with two other proteins (RecB and RecC to produce RecBCD enzyme, which is involved in homologous recombination and DNA repair in many bacteria, including Escherichia coli. However, RecD is not essential for DNA repair, nor does its deletion cause any growth defects in E. coli. Hence, the assessment of the P. syringae RecBCD pathway was imperative. METHODOLOGY/PRINCIPAL FINDINGS: Mutational analysis and genetic complementation studies were used to establish that the individual null-mutations of all three genes, recC, recB, and recD, or the deletion of whole recCBD operon of P. syringae, lead to growth inhibition at low temperature, and sensitivity to UV and mitomycin C. Viability of the mutant cells dropped drastically at 4 degrees C, and the mutants accumulated linear chromosomal DNA and shorter DNA fragments in higher amounts compared to 22 degrees C. Additional genetic data using the mutant RecBCD enzymes that were inactivated either in the ATPase active site of RecB (RecB(K29Q or RecD (RecD(K229Q, or in the nuclease center of RecB (RecB(D1118A and RecB(Delta nuc suggested that, while the nuclease activity of RecB is not so critical in vivo, the ATP-dependent functions of both RecB and RecD are essential. Surprisingly, E. coli recBCD or recBC alone on plasmid could complement the defects of the Delta recCBD strain of P. syringae. CONCLUSIONS/SIGNIFICANCE: All three subunits of the RecBCD(Ps enzyme are essential for DNA repair and growth of P. syringae at low temperatures (4 degrees C. The RecD requirement is only a function of the RecBCD complex in the bacterium. The RecBCD pathway protects the Antarctic bacterium from cold-induced DNA damages, and is critically dependent on the helicase activities of both RecB and RecD subunits, but not on the nuclease of RecBCD(Ps enzyme.

  15. A Class of Quasi-Distance and Singularity of Minkowski Complex Space%一类Minkowski复空间的拟距离和奇异性质

    Institute of Scientific and Technical Information of China (English)

    于学刚; 高云娥; 赵征

    2012-01-01

    双曲虚单位对应一类Minkowski复空间并具有方向异性的特点.四维时空中特殊方向上两时空点间的减法对应类时区与类光区的几何关联,在物理中表示粒子和场的相互作用.通过定义拟(虚)距离使Minkowsk空间的时空映射和间隔不变量进行度量公理化.四维时空中不同方向的距离或度量需要用线度因子和角度因子共同刻画,其中角度因子对应模糊集合,决定了Minkowski度量空间的奇异性质.%Hyperbolic imaginary unit is corresponding to the Minkowski complex space, which, possesses directional singularity. In four-dimensional space time, the subtraction between two space-time points in special direction corresponds to the geometric correlation between time-like region and light-like region, and it represents the interaction between particles and fields in physics. In the article, we make the spatio-temporal mapping and interval invariant axiomatic by defining quasi-distance. In four-dimensional space time, the distance of different directions can be depicted by both dimension factor and angle factor, where angle factor corresponds to fuzzy set, and determines the singularity of Minkowski complex space.

  16. Keeping Your Distance is Hard

    OpenAIRE

    Burke, Kyle; Heubach, Silvia; Huggan, Melissa; Huntemann, Svenja

    2016-01-01

    We study the computational complexity of distance games, a class of combinatorial games played on graphs. A move consists of colouring an uncoloured vertex subject to it not being at certain distances determined by two sets, D and S. D is the set of forbidden distances for colouring vertices in different colors, while S is the set of forbidden distances for the same colour. The last player to move wins. Well-known examples of distance games are Node-Kayles, Snort, and Col, whose complexities ...

  17. Unified QSAR & network-based computational chemistry approach to antimicrobials. II. Multiple distance and triadic census analysis of antiparasitic drugs complex networks.

    Science.gov (United States)

    Prado-Prado, Francisco J; Ubeira, Florencio M; Borges, Fernanda; González-Díaz, Humberto

    2010-01-15

    In the previous work, we reported a multitarget Quantitative Structure-Activity Relationship (mt-QSAR) model to predict drug activity against different fungal species. This mt-QSAR allowed us to construct a drug-drug multispecies Complex Network (msCN) to investigate drug-drug similarity (González-Díaz and Prado-Prado, J Comput Chem 2008, 29, 656). However, important methodological points remained unclear, such as follows: (1) the accuracy of the methods when applied to other problems; (2) the effect of the distance type used to construct the msCN; (3) how to perform the inverse procedure to study species-species similarity with multidrug resistance CNs (mdrCN); and (4) the implications and necessary steps to perform a substructural Triadic Census Analysis (TCA) of the msCN. To continue the present series with other important problem, we developed here a mt-QSAR model for more than 700 drugs tested in the literature against different parasites (predicting antiparasitic drugs). The data were processed by Linear Discriminate Analysis (LDA) and the model classifies correctly 93.62% (1160 out of 1239 cases) in training. The model validation was carried out by means of external predicting series; the model classified 573 out of 607, that is, 94.4% of cases. Next, we carried out the first comparative study of the topology of six different drug-drug msCNs based on six different distances such as Euclidean, Chebychev, Manhattan, etc. Furthermore, we compared the selected drug-drug msCN and species-species mdsCN with random networks. We also introduced here the inverse methodology to construct species-species msCN based on a mt-QSAR model. Last, we reported the first substructural analysis of drug-drug msCN using Triadic Census Analysis (TCA) algorithm. Copyright 2009 Wiley Periodicals, Inc.

  18. 人3型副流感病毒兰州分离株LZ22全基因组序列的测定及分析%Sequencing of Whole Genome of Human Parainfluenza Virus Type 3 Strain LZ22 Isolated in Lanzhou City,China

    Institute of Scientific and Technical Information of China (English)

    白慕群; 韩平; 安红; 胡广宏; 周旭

    2010-01-01

    目的 对人3型副流感病毒(HPIV-3)兰州分离株LZ22进行全基因组序列测定并分析.方法 通过引物步移法和RACE技术测定LZ22株的全基因组核苷酸序列,并分析其基因组结构特点和进化地位.结果 LZ22株的基因组全长15 462个核苷酸,符合副黏病毒科基因组"6碱基原则",按照3'-NP-PP/C-M-F-HN-L-5'的顺序编码6种结构蛋白,基因结构与已知序列HPIV-3分离株相同.与GenBank登录的4株HPIV-3参考株进行同源性比对发现,LZ22株与ZHYMgz01株(中国广州)的同源性最高,为99.0%(147个核苷酸变异),与14702株(加拿大)的同源性最低,为94.6%(832个核苷酸变异).系统进化分析表明,LZ22株与ZHYMgz01株为同一进化分支,与GP株(日本)进化关系次之,与14702株和JS株(美国)进化关系最远.结论 LZ22株病毒基因组具有副黏病毒的遗传特征,核苷酸序列与HPIV-3有高度的同源性.HPIV-3的系统进化可能与地域相关.

  19. Retrograde T-t Histories From Pelitic Migmatites Reflect Structural Distance From the Gwillim Creek Shear Zone, Valhalla Complex, British Columbia

    Science.gov (United States)

    Hallett, B. W.; Spear, F. S.

    2008-12-01

    Diffusion-zoned garnets from pelitic migmatites from the Valhalla metamorphic core complex, southeastern B.C. record relatively fast cooling rates that vary with distance above the Gwillim Creek shear zone (GCSZ). Fast cooling was caused by thrusting onto a cold footwall, where rocks closest to the fault began at the highest temperatures and conductively cooled at the fastest rate. Pelitic migmatites adjacent to and structurally above the GCSZ contain garnet with core to rim zoning of Fe/(Fe+Mg), controlled mainly by diffusion during progress of the retrograde net transfer reaction (ReNTR) Grt + Kfs + Melt = Bt + Sil + Plg. Where biotite is present in contact with garnet, retrograde Fe/Mg exchange has resulted in additional increased Fe/(Fe+Mg). A strongly foliated pelitic migmatite with pervasive 2-5mm-thick leucosomes from ~1.5 km structurally above the GCSZ contains garnet with Fe/(Fe+Mg) ranging from 0.72 to 0.93 and Xsps zoning with a uniform core (~0.02) and a near rim increase (to ~0.04). Interdiffusion of Fe+Mg was modeled with garnet radius varying linearly with temperature. This finite difference model calculates Fe-Mg interdiffusivity and generates a diffusion profile based on changing garnet rim boundary conditions governed by the ReNTR. Model fits to measured profiles require a 1-5 m.y. period of slow to moderate cooling (5-25°C/ m.y.) followed by a brief period (displacement on the Slocan Lake normal fault. 2-D thermal modeling of a low angle thrust ramp yields different T-t histories for hanging wall rocks based on their distance from the thrust. Model results show that transport on the order of cm/yr up a 10-20°-dipping thrust fault can produce cooling rates that are consistent with those calculated from garnet diffusion, and that the duration of initial slow cooling increases with distance from the fault.

  20. The upstream regulatory sequence of the light harvesting complex Lhcf2 gene of the marine diatom Phaeodactylum tricornutum enhances transcription in an orientation- and distance-independent fashion.

    Science.gov (United States)

    Russo, Monia Teresa; Annunziata, Rossella; Sanges, Remo; Ferrante, Maria Immacolata; Falciatore, Angela

    2015-12-01

    Diatoms are a key phytoplankton group in the contemporary ocean, showing extraordinary adaptation capacities to rapidly changing environments. The recent availability of whole genome sequences from representative species has revealed distinct features in their genomes, like novel combinations of genes encoding distinct metabolisms and a significant number of diatom-specific genes. However, the regulatory mechanisms driving diatom gene expression are still largely uncharacterized. Considering the wide variety of fields of study orbiting diatoms, ranging from ecology, evolutionary biology to biotechnology, it is thus essential to increase our understanding of fundamental gene regulatory processes such as transcriptional regulation. To this aim, we explored the functional properties of the 5'-flanking region of the Phaeodatylum tricornutum Lhcf2 gene, encoding a member of the Light Harvesting Complex superfamily and we showed that this region enhances transcription of a GUS reporter gene in an orientation- and distance-independent fashion. This represents the first example of a cis-regulatory sequence with enhancer-like features discovered in diatoms and it is instrumental for the generation of novel genetic tools and diatom exploitation in different areas of study. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Construction and Expression of Lactococcus lactis Expression Vector of lz-8 Gene from Ganoderma lucidum and Study of Its Immunological Characteristics%灵芝lz-8基因乳酸菌表达载体的构建与表达及免疫特性

    Institute of Scientific and Technical Information of China (English)

    曲宁宁; 陈萍; 孙鑫泽; 张雪; 刘琼

    2013-01-01

    Cloning and prokaryotic expression of Iz-8 gene from Ganoderma lucidum were conducted.Its physiological activity was tested through animals.The primers were designed according to the DNA sequence of lz-8 gene published in GenBank.The whole DNA from the mycelia of Ganoderma lucidum was purified.The lz-8 gene was amplified by PCR and cloned into the food-grade expression vector pNZ-8149 of Lactic acid bacteria.The recombinant plasmid was constructed and transferred into L.lactis NZ3900.After being induced by Nisin at 30 ℃ for 3 h,the recombinant protein was analysed by SDS-PAGE.The mice were fed with the bacterial suspension of NZ3900/pNZ8149-Iz-8 and their immune indexes such as carbon clearance index were tested.Results:A 330 bp lz-8 gene fragment was obtained.The prokaryotic recombined plasmid pNZ8149-Iz-8 was constructed.The NZ3900 transformed recombined plasmid pNZ8149-Iz-8 expressed LZ-8.Bacterial suspension of NZ3900/pNZ8149-Iz-8 had noticeable effects on the immune indexes in mice.The construction of the genetic engineering strain NZ3900/pNZ8149-Iz-8 had some effects on immune function in mice.%克隆灵芝Iz-8基因并进行原核表达,通过动物试验检测其生理活性.根据GenBank公布的Iz-8基因的DNA序列设计引物,从灵芝菌丝中提取灵芝总DNA,PCR扩增k-8基因并连接到乳酸菌食品级表达载体pNZ8149,转化乳酸乳球菌NZ3900,于30℃Nisin诱导3h,SDS-PAGE进行蛋白表达分析.将工程菌菌悬液给小鼠灌胃,对其碳廓清试验等免疫指标进行检测.结果表明:扩增到的Iz-8基因序列全长330 bp,构建了原核表达载体pNZ8149-Iz-8,LZ-8蛋白在NZ3900中得到表达.NZ3900/pNZ8149-Iz-8菌悬液对小鼠各项免疫指标有明显的调节作用.

  2. Accuracy and precision of reconstruction of complex refractive index in near-field single-distance propagation-based phase-contrast tomography

    Science.gov (United States)

    Gureyev, Timur; Mohammadi, Sara; Nesterets, Yakov; Dullin, Christian; Tromba, Giuliana

    2013-10-01

    We investigate the quantitative accuracy and noise sensitivity of reconstruction of the 3D distribution of complex refractive index, n(r)=1-δ(r)+iβ(r), in samples containing materials with different refractive indices using propagation-based phase-contrast computed tomography (PB-CT). Our present study is limited to the case of parallel-beam geometry with monochromatic synchrotron radiation, but can be readily extended to cone-beam CT and partially coherent polychromatic X-rays at least in the case of weakly absorbing samples. We demonstrate that, except for regions near the interfaces between distinct materials, the distribution of imaginary part of the refractive index, β(r), can be accurately reconstructed from a single projection image per view angle using phase retrieval based on the so-called homogeneous version of the Transport of Intensity equation (TIE-Hom) in combination with conventional CT reconstruction. In contrast, the accuracy of reconstruction of δ(r) depends strongly on the choice of the "regularization" parameter in TIE-Hom. We demonstrate by means of an instructive example that for some multi-material samples, a direct application of the TIE-Hom method in PB-CT produces qualitatively incorrect results for δ(r), which can be rectified either by collecting additional projection images at each view angle, or by utilising suitable a priori information about the sample. As a separate observation, we also show that, in agreement with previous reports, it is possible to significantly improve signal-to-noise ratio by increasing the sample-to-detector distance in combination with TIE-Hom phase retrieval in PB-CT compared to conventional ("contact") CT, with the maximum achievable gain of the order of 0.3δ /β. This can lead to improved image quality and/or reduction of the X-ray dose delivered to patients in medical imaging.

  3. Classification of periodic, chaotic and random sequences using approximate entropy and Lempel–Ziv complexity measures

    Indian Academy of Sciences (India)

    Karthi Balasubramanian; Silpa S Nair; Nithin Nagaraj

    2015-03-01

    ‘Complexity’ has several definitions in diverse fields. These measures are indicators of some aspects of the nature of the signal. Such measures are used to analyse and classify signals and as a signal diagnostics tool to distinguish between periodic, quasiperiodic, chaotic and random signals. Lempel–Ziv (LZ) complexity and approximate entropy (ApEn) are such popular complexity measures that are widely used for characterizing biological signals also. In this paper, we compare the utility of ApEn, LZ complexities and Shannon’s entropy in characterizing data from a nonlinear chaotic map (logistic map). In this work, we show that LZ and ApEn complexity measures can characterize the data complexities correctly for data sequences as short as 20 in length while Shannon’s entropy fails for length less than 50. In the case of noisy sequences with 10% uniform noise, Shannon’s entropy works only for lengths greater than 200 while LZ and ApEn are successful with sequences of lengths greater than 30 and 20, respectively.

  4. Reverse engineering of complex biological body parts by squared distance enabled non-uniform rational B-spline technique and layered manufacturing.

    Science.gov (United States)

    Pandithevan, Ponnusamy

    2015-02-01

    In tissue engineering, the successful modeling of scaffold for the replacement of damaged body parts depends mainly on external geometry and internal architecture in order to avoid the adverse effects such as pain and lack of ability to transfer the load to the surrounding bone. Due to flexibility in controlling the parameters, layered manufacturing processes are widely used for the fabrication of bone tissue engineering scaffold with the given computer-aided design model. This article presents a squared distance minimization approach for weight optimization of non-uniform rational B-spline curve and surface to modify the geometry that exactly fits into the defect region automatically and thus to fabricate the scaffold specific to subject and site. The study showed that though the errors associated in the B-spline curve and surface were minimized by squared distance method than point distance method and tangent distance method, the errors could be minimized further in the rational B-spline curve and surface as the optimal weight could change the shape that desired for the defect site. In order to measure the efficacy of the present approach, the results were compared with point distance method and tangent distance method in optimizing the non-rational and rational B-spline curve and surface fitting for the defect site. The optimized geometry then allowed to construct the scaffold in fused deposition modeling system as an example. The result revealed that the squared distance-based weight optimization of the rational curve and surface in making the defect specific geometry best fits into the defect region than the other methods used. © IMechE 2015.

  5. Rock magnetic properties, magnetic susceptibility, and organic geochemistry comparison in core LZ1029-7 Lake El'gygytgyn, Far Eastern Russia

    Directory of Open Access Journals (Sweden)

    K. J. Murdock

    2012-09-01

    Full Text Available Susceptibility measurements performed on initial short (3–16 m cores taken from Lake El'gygytgyn exhibited a large range in values. This observation led to the suggestion of widespread magnetite dissolution within the sediments due to anoxic conditions within the lake. Rock magnetic properties and their comparison with magnetic susceptibility, Total Organic Carbon (TOC, and bulk δ13Corg proxies in core LZ1029-7 provide an insight into the character of the magnetic minerals present within the lake and can further the understanding of processes that may be present in the newer long core sediments Susceptibility measurements (χ of discrete samples corroborate the two order of magnitude difference seen in previous continuous susceptibility measurements (κ, correlating high values with interglacial periods and low values with glacial intervals. Hysteresis parameters defined the majority of the magnetic material to be magnetite of PSD size. TOC values increase while δ13Corg values decrease in one section of LZ1029-7, which is defined as the Last Glacial Maximum (LGM, and help confine the age of the core to approximately 62 kyr. Increases in TOC during the most recent glacial interval suggest increased preservation of organic carbon during these times High TOC and low magnetic susceptibility during the LGM support the theory of perennial ice cover during glacial periods, which would lead to lake stratification and therefore anoxic bottom water conditions. Low temperature magnetic measurements also confirmed the presence of magnetite, but also indicated titanomagnetite, siderite and/or rhodochrosite, and vivianite were present. The latter three minerals are found only in anoxic environments, and further support the notion of magnetite dissolution.

  6. Rock magnetic properties, magnetic susceptibility, and organic geochemistry comparison in core LZ1029-7 Lake El'gygytgyn, Russia Far East

    Directory of Open Access Journals (Sweden)

    K. J. Murdock

    2013-02-01

    Full Text Available Susceptibility measurements performed on initial short (~ 16 m cores PG1351 taken from Lake El'gygytgyn exhibited a large range in values. This observation led to the suggestion of widespread magnetite dissolution within the sediments due to anoxic conditions within the lake. Rock magnetic properties and their comparison with magnetic susceptibility, total organic carbon (TOC, and bulk δ13Corg proxies in core LZ1029-7, taken from the same site as the previously drilled PG1351, provide an insight into the character of the magnetic minerals present within the lake and can further the understanding of processes that may be present in the newer long core sediments. Susceptibility measurements (χ of discrete samples corroborate the two order of magnitude difference seen in previous continuous susceptibility measurements (κ, correlating high values with interglacial periods and low values with glacial intervals. Hysteresis parameters indicate that the majority of the magnetic material to be magnetite of PSD size. TOC values increase while δ13Corg values decrease in one section of LZ1029-7, which is defined as the Last Glacial Maximum (LGM, and help confine the age of the core to approximately 62 ka. Increases in TOC during the most recent glacial interval suggest increased preservation of organic carbon during this period. High TOC and low magnetic susceptibility during the LGM support the theory of perennial ice cover during glacial periods, which would lead to lake stratification and therefore anoxic bottom water conditions. Low temperature magnetic measurements confirmed the presence of magnetite, but also indicated titanomagnetite and possibly siderite, rhodochrosite, and/or vivianite were present. The latter three minerals are found only in anoxic environments, and further support the notion of magnetite dissolution.

  7. On distances between phylogenetic trees

    Energy Technology Data Exchange (ETDEWEB)

    DasGupta, B. [Rutgers Univ., Camden, NJ (United States); He, X. [SUNY, Buffalo, NY (United States); Jiang, T. [McMaster Univ., Hamilton, Ontario (Canada)] [and others

    1997-06-01

    Different phylogenetic trees for the same group of species are often produced either by procedures that use diverse optimality criteria or from different genes in the study of molecular evolution. Comparing these trees to find their similarities and dissimilarities, i.e. distance, is thus an important issue in computational molecular biology. The nearest neighbor interchange distance and the subtree-transfer distance are two major distance metrics that have been proposed and extensively studied for different reasons. Despite their many appealing aspects such as simplicity and sensitivity to tree topologies, computing these distances has remained very challenging. This article studies the complexity and efficient approximation algorithms for computing the nni distance and a natural extension of the subtree-transfer distance, called the linear-cost subtree-transfer distance. The linear-cost subtree-transfer model is more logical than the subtree-transfer model and in fact coincides with the nni model under certain conditions. The following results have been obtained as part of our project of building a comprehensive software package for computing distances between phylogenies. (1) Computing the nni distance is NP-complete. This solves a 25 year old open question appearing again and again in, for example, under the complexity-theoretic assumption of P {ne} NP. We also answer an open question regarding the nni distance between unlabeled trees for which an erroneous proof appeared in. We give an algorithm to compute the optimal nni sequence in time O(n{sup 2} logn + n {circ} 2{sup O(d)}), where the nni distance is at most d. (2) Biological applications require us to extend the nni and linear-cost subtree-transfer models to weighted phylogenies, where edge weights indicate the length of evolution along each edge. We present a logarithmic ratio approximation algorithm for nni and a ratio 2 approximation algorithm for linear-cost subtree-transfer, on weighted trees.

  8. Peroxidase-benzhydroxamic acid complexes: spectroscopic evidence that a Fe-H2O distance of 2.6 A can correspond to hexa-coordinate high-spin heme.

    Science.gov (United States)

    Smulevich, G; Feis, A; Indiani, C; Becucci, M; Marzocchi, M P

    1999-02-01

    Resonance Raman (RR) spectra have been obtained for single-crystal horseradish peroxidase isozyme C complexed with benzhydroxamic acid (BHA). The data are compared with those obtained in solution by both RR and electronic absorption spectroscopies at room and low (12-80 K) temperatures. Moreover, the analysis has been extended to Coprinus cinereus peroxidase complexed with BHA. The results obtained for the two complexes are very similar and are consistent with the presence of an aqua six-coordinate high-spin heme. Therefore it can be concluded that despite the rather long Fe-H2O distance of 2.6-2.7 A found by X-ray crystallography in both complexes, the distal water molecule can still coordinate to the heme iron.

  9. Three Perspectives on Complexity $-$ Entropy, Compression, Subsymmetry

    CERN Document Server

    Nagaraj, Nithin

    2016-01-01

    There is no single universally accepted definition of "Complexity". There are several perspectives on complexity and what constitutes complex behaviour or complex systems, as opposed to regular, predictable behaviour and simple systems. In this paper, we explore the following perspectives on complexity: "effort-to-describe" (Shannon entropy $H$, Lempel-Ziv complexity $LZ$), "effort-to-compress" ($ETC$ complexity) and "degree-of-order" (Subsymmetry or $SubSym$). While Shannon entropy and $LZ$ are very popular and widely used, $ETC$ is a recently proposed measure for time series. In this paper, we also propose a novel normalized measure $SubSym$ based on the existing idea of counting the number of subsymmetries or palindromes within a sequence. We compare the performance of these complexity measures on the following tasks: a) characterizing complexity of short binary sequences of lengths 4 to 16, b) distinguishing periodic and chaotic time series from 1D logistic map and 2D H\\'{e}non map, and c) distinguishing ...

  10. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  11. Complex

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.

  12. A computational study of structural and magnetic properties of bi- and trinuclear Cu(II) complexes with extremely long Cu-Cu distances

    Science.gov (United States)

    Baryshnikov, Gleb V.; Minaev, Boris F.; Baryshnikova, Alina T.; Ågren, Hans

    2017-07-01

    Three recently synthesized copper(II) complexes with aroylhydrazones of trifluoroacetic and benzenecarboxylic acids (Dalton Trans., 2013, 42, 16878) have been computationally investigated by density functional theory within the broken symmetry approximation accounting for empirical dispersion corrections. A topological analysis of electron density distributions has been carried out using Bader's ;quantum theory of atoms in molecules; formalism. The calculated values of spin-spin exchange for the studied dinuclear complexes indicate a very weak ferromagnetic coupling of the unpaired electrons in good agreement with experimental data. At the same time, the trinuclear copper(II) complex possesses a low-spin doublet ground state with one ferromagnetic and two antiferromagnetic spin projections between the triangular-positioned Cu2+ ions. The estimated values of the coupling constants for the spin-spin exchange in this trinuclear complex are in a good agreement with experimental observations. The calculations support a mechanism of exchange coupling through the aromatic links in these strongly spin-separated systems.

  13. Nearest-neighbor nitrogen and oxygen distances in the iron(II)-DNA complex studied by extended X-ray absorption fine structure.

    Science.gov (United States)

    Bertoncini, Clelia R A; Meneghini, Rogerio; Tolentino, Helio

    2010-11-01

    In mammalian cells, DNA-bound Fe(II) reacts with H₂O₂ producing the highly reactive hydroxyl radical (OH) in situ. Since ·OH attacks nearby DNA residue generating oxidative DNA damage, many questions have arisen regarding iron-DNA complex formations and their implication in pre-malignant mutations and aging. In this work, a solid sample of Fe(II)-DNA complex containing one Fe(II) per 10 nucleotides was analyzed from extended X-ray absorption fine structure (EXAFS) spectra collected in a synchrotron radiation light source. Best fitting parameters of the EXAFS signal for the first two shells provide evidence of five oxygen atoms at 1.99 ± 0.02 Å and one nitrogen atom at 2.20 ± 0.02 Å in the inner coordination sphere of the Fe(II)-DNA complex. Considering that both purine base moieties bearing nitrogen atoms are prone to chelate iron, these results are consistent with the previously observed lower levels of DNA damage in cytosine nucleotides relative to adenine and guanine sites in cells under more physiological conditions of Fe(II) Fenton reaction.

  14. Six-minute walking distance improvement after pulmonary rehabilitation is associated with baseline lung function in complex COPD patients: a retrospective study.

    Science.gov (United States)

    Zanini, Andrea; Chetta, Alfredo; Gumiero, Federico; Della Patrona, Sabrina; Casale, Silvia; Zampogna, Elisabetta; Aiello, Marina; Spanevello, Antonio

    2013-01-01

    Conflicting results have been so far reported about baseline lung function, as predicting factor of pulmonary rehabilitation (PR) efficacy. To ascertain whether or not baseline lung function could predict a benefit in terms of a significant change in 6-min walk test (6 MWT) after PR. Seventy-five stable moderate-to-severe COPD inpatients with comorbidities (complex COPD), allocated to a three-week PR program, were retrospectively evaluated. Pulmonary function, 6 MWT, dyspnea (BDI/TDI), and quality of life (EQ-VAS) were assessed before and after PR program. The patients were divided into two groups depending on the change in 6 MWT (responders > 30 m and nonresponders ≤ 30 m). Logistic regression analysis was used. Results. After PR, 6 MWT performance all outcome measures significantly improved (P function (P PR efficacy. Our study shows that in stable moderate-to-severe complex COPD inpatients, baseline lung function may predict the response to PR in terms of 6 MWT. We also found that complex COPD patients with poor lung function get more benefit from PR.

  15. An algorithm for identifying protein complexes based on clique percolation and distance restriction%基于团渗透和距离限制的蛋白质复合物识别算法

    Institute of Scientific and Technical Information of China (English)

    刘彬彬; 李敏; 王建新; 段桂华

    2012-01-01

    算法CPM (clique percolation method)作为一种有效的识别复杂网络中交叠模块结构的算法在社会网络和生物网络中得到了广泛应用.但,CPM算法应用于蛋白质相互作用网络时蛋白质复合物识别准确率不高,且不利于识别规模适中的蛋白质复合物.为克服CPM算法的不足,本文通过引入距离限制约束识别的蛋白质复合物的规模,进而提出了一种基于团渗透和距离限制的蛋白质复合物识别算法CPM-DR.基于酵母蛋白质相互作用网络平台的实验结果表明,算法CPM-DR比CPM能够更准确、更有效、更全面的识别出具有特定生物意义的蛋白质复合物.%Identification of protein complexes in large interaction networks is crucial to understand principles of cellular organization and predict protein functions, which is one of the most important issues in the post-genomic era. Each protein might subordinate multiple protein complexes in the real protein-protein interaction networks. Identifying overlapping protein complexes from protein-protein interaction networks is a considerable research topic. As an effective algorithm on identifying overlapping module structures, clique percolation method (CPM) has a wide range of application in social networks and biological networks. However, CPM algorithm is recognition accuracy rate lowly and unfit to identifying protein complexes with middling scale when it applied in PPI networks. In this paper, an algorithm called CPM-DR for identifying protein complexes based on clique percolation and distance restriction is proposed. In this algorithm, the scale of protein complex is restricted by distance constraint to conquest the drawbacks in CPM. The experiment results show that CPM-DR algorithm can identify many well known protein complexes more effectively, precisely and comprehensively.

  16. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2016-01-01

    This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...

  17. Distance Education Council.

    Science.gov (United States)

    Indira Gandhi National Open University, New Delhi (India). Distance Education Council.

    Since its inception in India in 1962, distance education has grown in popularity. The Distance Education Council (DEC) directs distance learning within India's higher education system. The DEC's promotion, coordination, and maintenance of standards for distance education are its three major roles. Its initiatives include grants, support for…

  18. Training for Distance Teaching through Distance Learning.

    Science.gov (United States)

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  19. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2014-01-01

    This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...

  20. Distances from Planetary Nebulae

    CERN Document Server

    Ciardullo, R

    2003-01-01

    The [O III] 5007 planetary nebula luminosity function (PNLF) occupies an important place on the extragalactic distance ladder. Since it is the only method that is applicable to all the large galaxies of the Local Supercluster, it is uniquely useful for cross-checking results and linking the Population I and Population II distance scales. We review the physics underlying the method, demonstrate its precision, and illustrate its value by comparing its distances to distances obtained from Cepheids and the Surface Brightness Fluctuation (SBF) method. We use the Cepheid and PNLF distances to 13 galaxies to show that the metallicity dependence of the PNLF cutoff is in excellent agreement with that predicted from theory, and that no additional systematic corrections are needed for either method. However, when we compare the Cepheid-calibrated PNLF distance scale with the Cepheid-calibrated SBF distance scale, we find a significant offset: although the relative distances of both methods are in excellent agreement, th...

  1. 4LZ-0.8型水稻联合收割机清选装置气固两相分离作业机理%Gas-solid two-phase separation operation mechanism for 4LZ-0.8 rice combine harvester cleaning device

    Institute of Scientific and Technical Information of China (English)

    任述光; 谢方平; 王修善; 刘大为; 李旭; 陈立永

    2015-01-01

    为解决小型水稻联合收割机脱净率和损失率问题,提高脱粒清选质量,利用两相流动力学理论,分析了4LZ-0.8型水稻联合收割机脱粒清选分流筒中气流和杂物颗粒两相流动的规律。建立了杂物颗粒流的运动微分方程,导出了分离筒中杂物漂浮速度计算的一种方法,通过比较不同粒径、密度的物料的悬浮速度,得到了杂物颗粒最高速度与气流速度之比随气流速度变化的关系曲线,气流和杂物在分流筒及吸风管中运动时的压力损失随气流速度变化呈现先降后升的规律,压力损失中以加速损失和摩擦损失为主,各约占30%和26%。压力损失曲线存在最小值,此时的气流速度定义为经济气流速度。在喂入量为0.8 kg/s,谷草比为3:1脱粒条件下的经济的清选气流速度9.2 m/s,压力损失为630 Pa。该研究为4LZ-0.8型水稻联合收割机脱粒清选部件的参数优化设计及风机的选择提供了理论依据。%Using the theory of two-phase flow dynamics, the law of two-phase flow formed by airflow and sundry grain in the threshing cleaning shunt tube of the 4LZ-0.8 type of rice combine harvester is studied in this paper. The movement differential equation of sundry grain flow is established and the sundry suspension speed is deduced. A method for calculating the suspension velocities of the particles with different sizes and densities is analyzed in the paper. The curve of the ratio of the highest sundry particle velocity to the air velocity varying with air velocity is obtained. The pressure loss in the air and debris flow in shunt tube is analyzed, and the most economical cleaning air velocity under a certain mass flow is calculated. All of these provide a theoretical basis for the parameter design of 4LZ-0.8 type of rice combine harvester’s threshing cleaning parts. Material in the flow field is subjected to aerodynamic drag and the role of its own gravity

  2. A generalized evidence distance

    Institute of Scientific and Technical Information of China (English)

    Hongming Mo; Xi Lu; Yong Deng

    2016-01-01

    How to efficiently measure the distance between two basic probability assignments (BPAs) is an open issue. In this paper, a new method to measure the distance between two BPAs is proposed, based on two existing measures of evidence distance. The new proposed method is comprehen-sive and generalized. Numerical examples are used to ilus-trate the effectiveness of the proposed method.

  3. Dynamics of Symmetric Conserved Mass Aggregation Model on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    HUA Da-Yin

    2009-01-01

    We investigate the dynamical behaviour of the aggregation process in the symmetric conserved mass aggregation model under three different topological structures. The dispersion σ(t, L) = (∑i(mi - ρ0)2/L)1/2 is defined to describe the dynamical behaviour where ρ0 is the density of particle and mi is the particle number on a site. It is found numerically that for a regular lattice and a scale-free network, σ(t, L) follows a power-law scaling σ(t, L) ~ tδ1 and σ(t, L) ~ tδ4 from a random initial condition to the stationary states, respectively. However, for a small-world network, there are two power-law scaling regimes, σ(t, L) ~ tδ2 when t<T and a(t, L) ~ tδ3 when tT. Moreover, it is found numerically that δ2 is near to δ1 for small rewiring probability q, and δ3 hardly changes with varying q and it is almost the same as δ4. We speculate that the aggregation of the connection degree accelerates the mass aggregation in the initial relaxation stage and the existence of the long-distance interactions in the complex networks results in the acceleration of the mass aggregation when tT for the small-world networks. We also show that the relaxation time T follows a power-law scaling τ Lz and σ(t, L) in the stationary state follows a power-law σs(L) ~ Lσ for three different structures.

  4. Leucine zipper motif in RRS1 is crucial for the regulation of Arabidopsis dual resistance protein complex RPS4/RRS1.

    Science.gov (United States)

    Narusaka, Mari; Toyoda, Kazuhiro; Shiraishi, Tomonori; Iuchi, Satoshi; Takano, Yoshitaka; Shirasu, Ken; Narusaka, Yoshihiro

    2016-01-11

    Arabidopsis thaliana leucine-rich repeat-containing (NLR) proteins RPS4 and RRS1, known as dual resistance proteins, confer resistance to multiple pathogen isolates, such as the bacterial pathogens Pseudomonas syringae and Ralstonia solanacearum and the fungal pathogen Colletotrichum higginsianum. RPS4 is a typical Toll/interleukin 1 Receptor (TIR)-type NLR, whereas RRS1 is an atypical TIR-NLR that contains a leucine zipper (LZ) motif and a C-terminal WRKY domain. RPS4 and RRS1 are localised near each other in a head-to-head orientation. In this study, direct mutagenesis of the C-terminal LZ motif in RRS1 caused an autoimmune response and stunting in the mutant. Co-immunoprecipitation analysis indicated that full-length RPS4 and RRS1 are physically associated with one another. Furthermore, virus-induced gene silencing experiments showed that hypersensitive-like cell death triggered by RPS4/LZ motif-mutated RRS1 depends on EDS1. In conclusion, we suggest that the RRS1-LZ motif is crucial for the regulation of the RPS4/RRS1 complex.

  5. Tourists consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...

  6. Learning string edit distance

    CERN Document Server

    Ristad, E S; Ristad, Eric Sven; Yianilos, Peter N.

    1996-01-01

    In many applications, it is necessary to determine the similarity of two strings. A widely-used notion of string similarity is the edit distance: the minimum number of insertions, deletions, and substitutions required to transform one string into the other. In this report, we provide a stochastic model for string edit distance. Our stochastic model allows us to learn a string edit distance function from a corpus of examples. We illustrate the utility of our approach by applying it to the difficult problem of learning the pronunciation of words in conversational speech. In this application, we learn a string edit distance with one fourth the error rate of the untrained Levenshtein distance. Our approach is applicable to any string classification problem that may be solved using a similarity function against a database of labeled prototypes. Keywords: string edit distance, Levenshtein distance, stochastic transduction, syntactic pattern recognition, prototype dictionary, spelling correction, string correction, ...

  7. Interface Simulation Distances

    Directory of Open Access Journals (Sweden)

    Pavol Černý

    2012-10-01

    Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.

  8. Sublinear distance labeling for sparse graphs

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Dahlgaard, Søren; Knudsen, Mathias Bæk Tejs;

    2015-01-01

    between pairs of nodes that are at distance at least $D$ from each other. In this paper we consider distance labeling schemes for the classical case of unweighted and undirected graphs. We present the first distance labeling scheme of size $o(n)$ for sparse graphs (and hence bounded degree graphs......). This addresses an open problem by Gavoille et. al. [J. Algo. 2004], hereby separating the complexity from general graphs which require $\\Omega(n)$ size Moon [Proc. of Glasgow Math. Association 1965]. As an intermediate result we give a $O(\\frac{n}{D}\\log^2 D)$ $D$-preserving distance labeling scheme, improving...

  9. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu

    2009-01-01

    Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot\\'s number of degrees of freedom. In addition to supporting efficient sampling, we show that the RD-space formulation naturally supports planning, and in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1000 links in time comparable to open chain sampling, and we can generate samples for 1000-link multi-loop systems of varying topology in less than a second. © 2009 Springer-Verlag.

  10. Keeping Your Distance

    Directory of Open Access Journals (Sweden)

    Glen Gatin

    2013-06-01

    Full Text Available This analysis began with inquiries into the substantive area of distance education using the classic grounded theory method. Analysis revealed a pattern of problemsolving behavior, from which the theory Keeping Your Distance emerged. The theory is an integrated set of concepts referring to the conscious and unconscious strategiesthat people use to regulate distance, physical and representative, in their everyday lives. Strategies are used to control physical, emotional, and psychological realities and to conserve personal energy in interactions with individuals and/or institutions.For all social interactions, people use a personalized algorithm of engagement that mitigates conditions and consequences and preserves optimal distance. Keeping Your Distance provides a theoretical starting point for considerations of the changing notions of distance. In part, these changes have been brought about bydevelopments in the fields of Information and Communication Technology (ICT and online social networking.

  11. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  12. Incremental Distance Transforms (IDT)

    NARCIS (Netherlands)

    Schouten, Theo E.; van den Broek, Egon; Erçil, A.; Çetin, M.; Boyer, K.; Lee, S.-W.

    2010-01-01

    A new generic scheme for incremental implementations of distance transforms (DT) is presented: Incremental Distance Transforms (IDT). This scheme is applied on the cityblock, Chamfer, and three recent exact Euclidean DT (E2DT). A benchmark shows that for all five DT, the incremental implementation r

  13. ORDERED WEIGHTED DISTANCE MEASURE

    Institute of Scientific and Technical Information of China (English)

    Zeshui XU; Jian CHEN

    2008-01-01

    The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

  14. Duty and Distance

    NARCIS (Netherlands)

    C. Binder (C.); C. Heilmann (Conrad)

    2017-01-01

    markdownabstractEver since the publication of Peter Singer’s article ‘‘Famine, Affluence, and Morality’’ has the question of whether the (geographical) distance to people in need affects our moral duties towards them been a hotly debated issue. Does geographical distance affect our moral duties?

  15. Biomechanics of Distance Running.

    Science.gov (United States)

    Cavanagh, Peter R., Ed.

    Contributions from researchers in the field of running mechanics are included in the 13 chapters of this book. The following topics are covered: (1) "The Mechanics of Distance Running: A Historical Perspective" (Peter Cavanagh); (2) "Stride Length in Distance Running: Velocity, Body Dimensions, and Added Mass Effects" (Peter Cavanagh, Rodger…

  16. Distance Learning Environment Demonstration.

    Science.gov (United States)

    1996-11-01

    The Distance Learning Environment Demonstration (DLED) was a comparative study of distributed multimedia computer-based training using low cost high...measurement. The DLED project provides baseline research in the effective use of distance learning and multimedia communications over a wide area ATM/SONET

  17. Duty and Distance

    NARCIS (Netherlands)

    C. Binder (C.); C. Heilmann (Conrad)

    2017-01-01

    markdownabstractEver since the publication of Peter Singer’s article ‘‘Famine, Affluence, and Morality’’ has the question of whether the (geographical) distance to people in need affects our moral duties towards them been a hotly debated issue. Does geographical distance affect our moral

  18. Estimating distances from parallaxes

    Science.gov (United States)

    Astraatmadja, Tri L.; Bailer-Jones, Coryn

    2017-01-01

    In astrometric surveys such as Gaia and LSST, parallaxes will be measured for about a billion stars, but zero distances will be measured. Distances must be inferred from the parallaxes, and the common inference practice is by inverting the parallax. This, however, is only appropriate when there is no noise present. As noise will always be present and most stars in future surveys will have non-negligible fractional parallax uncertainties, we must treat distance estimation as an inference problem. The usage of prior assumptions become unavoidable. In this talk I will present a method on how to infer distances using Bayesian inference. Three minimalists, isotropic priors are used, as well an anisotropic prior derived from the observability of stars in a Milky Way model. The performance of these priors are investigated using a simulated Gaia-like catalogue. Recent results of distance estimation using the parallaxes of 2 million Gaia DR1 stars will also be discussed.

  19. Making Distance Visible: Assembling Nearness in an Online Distance Learning Programme

    Science.gov (United States)

    Ross, Jen; Gallagher, Michael Sean; Macleod, Hamish

    2013-01-01

    Online distance learners are in a particularly complex relationship with the educational institutions they belong to (Bayne, Gallagher, & Lamb, 2012). For part-time distance students, arrivals and departures can be multiple and invisible as students take courses, take breaks, move into independent study phases of a programme, find work or…

  20. Estimating distances from parallaxes

    CERN Document Server

    Bailer-Jones, C A L

    2015-01-01

    Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case for about 80% of stars in the Gaia catalogue. Estimating distances is an inference problem in which the use of prior assumptions is unavoidable. I investigate the properties and performance of various priors and examine their implications. A supposed uninformative uniform prior in distance is shown to give very poor distance estimates (large bias and variance). Any prior with a sharp cut-off at some distance has similar problems. The choice of prior depends on the information one has available - and is willing to use - concerning, for example, the survey and the Galaxy. I demonstrate that a simple prior which decreases asymptotically to zero at infinite distance has g...

  1. Research in Distance Education: A Status Report

    Directory of Open Access Journals (Sweden)

    Farhad Saba

    2000-06-01

    Full Text Available Since the 1950s and expansion of social science research, distance education has been studied in comparison to face-to-face or classroom instruction. Although researchers continue to conduct comparative studies, their usefulness in revealing more information has diminished over the years; invariably, they have returned a “no significant difference” result between various forms of instruction. In recent years, researchers have moved beyond atheoretical, experimental comparative studies and have introduced new methods, such as discourse analysis, and in-depth interview of learners. These new methods overcome many methodological and theoretical limitations of the physical science view of distance education. These studies have further revealed the complexity of distance education, indicating the many variables involved in the concept. Starting with the core issue of instructional interaction and grounded on the theory of transactional distance, a new strand of research using methods related to systems dynamics, hierarchy and complexity theories, promises a more comprehensive understanding.

  2. MOTIVATION FOR DISTANCE EDUCATION

    Directory of Open Access Journals (Sweden)

    R zvan TEF NESCU

    2009-10-01

    Full Text Available Beginning with the 1980’s the new information, communication and computer based technologies stimulated the development of the distance education. In Romania the universities adapted rapidly to this type of learning that became an important financing source for most of them. In this article we approach the causes of attraction for the distance education. For this purpose we use an investigation we did on a group of students at Distance Education including interviews regarding their reasons for choosing this type of learning.

  3. Distance learning perspectives.

    Science.gov (United States)

    Pandza, Haris; Masic, Izet

    2013-01-01

    The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning.

  4. Learning Pullback HMM Distances.

    Science.gov (United States)

    Cuzzolin, Fabio; Sapienza, Michael

    2014-07-01

    Recent work in action recognition has exposed the limitations of methods which directly classify local features extracted from spatio-temporal video volumes. In opposition, encoding the actions' dynamics via generative dynamical models has a number of attractive features: however, using all-purpose distances for their classification does not necessarily deliver good results. We propose a general framework for learning distance functions for generative dynamical models, given a training set of labelled videos. The optimal distance function is selected among a family of pullback ones, induced by a parametrised automorphism of the space of models. We focus here on hidden Markov models and their model space, and design an appropriate automorphism there. Experimental results are presented which show how pullback learning greatly improves action recognition performances with respect to base distances.

  5. Approximate Graph Edit Distance in Quadratic Time.

    Science.gov (United States)

    Riesen, Kaspar; Ferrer, Miquel; Bunke, Horst

    2015-09-14

    Graph edit distance is one of the most flexible and general graph matching models available. The major drawback of graph edit distance, however, is its computational complexity that restricts its applicability to graphs of rather small size. Recently the authors of the present paper introduced a general approximation framework for the graph edit distance problem. The basic idea of this specific algorithm is to first compute an optimal assignment of independent local graph structures (including substitutions, deletions, and insertions of nodes and edges). This optimal assignment is complete and consistent with respect to the involved nodes of both graphs and can thus be used to instantly derive an admissible (yet suboptimal) solution for the original graph edit distance problem in O(n3) time. For large scale graphs or graph sets, however, the cubic time complexity may still be too high. Therefore, we propose to use suboptimal algorithms with quadratic rather than cubic time for solving the basic assignment problem. In particular, the present paper introduces five different greedy assignment algorithms in the context of graph edit distance approximation. In an experimental evaluation we show that these methods have great potential for further speeding up the computation of graph edit distance while the approximated distances remain sufficiently accurate for graph based pattern classification.

  6. Fingerprinting with Minimum Distance Decoding

    CERN Document Server

    Lin, Shih-Chun; Gamal, Hesham El

    2007-01-01

    This work adopts an information theoretic framework for the design of collusion-resistant coding/decoding schemes for digital fingerprinting. More specifically, the minimum distance decision rule is used to identify 1 out of t pirates. Achievable rates, under this detection rule, are characterized in two distinct scenarios. First, we consider the averaging attack where a random coding argument is used to show that the rate 1/2 is achievable with t=2 pirates. Our study is then extended to the general case of arbitrary $t$ highlighting the underlying complexity-performance tradeoff. Overall, these results establish the significant performance gains offered by minimum distance decoding as compared to other approaches based on orthogonal codes and correlation detectors. In the second scenario, we characterize the achievable rates, with minimum distance decoding, under any collusion attack that satisfies the marking assumption. For t=2 pirates, we show that the rate $1-H(0.25)\\approx 0.188$ is achievable using an ...

  7. Advanced low-complexity compression for maskless lithography data

    Science.gov (United States)

    Dai, Vito; Zakhor, Avideh

    2004-05-01

    A direct-write maskless lithography system using 25nm for 50nm feature sizes requires data rates of about 10 Tb/s to maintain a throughput of one wafer per minute per layer achieved by today"s optical lithography systems. In a previous paper, we presented an architecture that achieves this data rate contingent on 25 to 1 compression of lithography data, and on implementation of a real-time decompressor fabricated on the same chip as a massively parallel array of lithography writers for 50 nm feature sizes. A number of compression techniques, including JBIG, ZIP, the novel 2D-LZ, and BZIP2 were demonstrated to achieve sufficiently high compression ratios on lithography data to make the architecture feasible, although no single technique could achieve this for all test layouts. In this paper we present a novel lossless compression algorithm called Context Copy Combinatorial Code (C4) specifically tailored for lithography data. It successfully combines the advantages of context-based modeling in JBIG and copying in ZIP to achieve higher compression ratios across all test layouts. As part of C4, we have developed a low-complexity binary entropy coding technique called combinatorial coding which is simultaneously as efficient as arithmetic coding and as fast as Huffman coding. Compression results show C4 outperforms JBIG, ZIP, BZIP2, and 2D-LZ, and achieves lossless compression ratios greater than 22 for binary layout image data, and greater than 14 for grey-pixel image data. The tradeoff between decoder buffer size, which directly affects implementation complexity and compression ratio is examined. For the same buffer size, C4 achieves higher compression than LZ77, ZIP, and BZIP2.

  8. 3D Distance Fields: A Survey of Techniques and Applications

    DEFF Research Database (Denmark)

    Jones, Mark; Bærentzen, Jakob Andreas; Sramek, Milos

    2006-01-01

    A distance field is a representation where at each point within the field we know the distance from that point to the closest point on any object within the domain. In addition to distance, other properties may be derived from the distance field, such as the direction to the surface, and when the...... simple are they to implement? - What is the complexity and run-time of such methods?...

  9. Presence at a distance.

    Science.gov (United States)

    Haddouk, Lise

    2015-01-01

    Nowadays in the context of the cyberculture, computer-mediated inter-subjective relationships are part of our everyday lives, in both the professional and personal spheres, and for all age groups. In the clinical field, many applications have been developed to facilitate the exchange of informations and mediate the relationship between patient and therapist. In psychology, more or less immersive technologies are used, to encourage the feeling of presence among the users, and to trigger certain psychological processes. In our research, we have explored the remote clinical interview through videoconferencing, with the development and utilisation of the iPSY platform, totally focused on this objective. In this context, we have considered the notion of intersubjectivity, despite the physical absence. This research is leading us today to envision the notions of distance and presence, and possibly to redefine them. Thus, can we still oppose physical distance to psychological distance? Can we still affirm that the physical absence does not permit a psychological co-presence in certain interactions, like this observed in video interviews? The results show that the psychological processes, activated in this context, are similar to those observed in "traditional" clinical consults between the patient and the therapist. However, certain specifics have led us to consider the concept of distance, here influenced by the framework, and to observe its effects. This distance could possibly constitute a therapeutic lever for some patients, notably for those who have difficulties establishing the right psychological distance in their relationships with others. According to these results, can "distance" still be opposed to "presence", or could it be re-defined? This also opens up questions on the more general concept of digital relationships, and the definition of their specificities.

  10. Normalized Information Distance is Not Semicomputable

    CERN Document Server

    Terwijn, Sebastiaan A; Vitanyi, Paul M B

    2010-01-01

    Normalized information distance (NID) uses the theoretical notion of Kolmogorov complexity, which for practical purposes is approximated by the length of the compressed version of the file involved, using a real-world compression program. This practical application is called 'normalized compression distance' and it is trivially computable. It is a parameter-free similarity measure based on compression, and is used in pattern recognition, data mining, phylogeny, clustering, and classification. The complexity properties of its theoretical precursor, the NID, have been open. We show that the NID is neither upper semicomputable nor lower semicomputable.

  11. Nonapproximablity of the Normalized Information Distance

    CERN Document Server

    Terwijn, Sebastiaan A; Vitanyi, Paul M B

    2009-01-01

    Normalized information distance (NID) uses the theoretical notion of Kolmogorov complexity, which for practical purposes is approximated by the length of the compressed version of the file involved, using a real-world compression program. This practical application is called `normalized compression distance' and it is trivially computable. It is a parameter-free similarity measure based on compression, and is used in pattern recognition, data mining, phylogeny, clustering, and classification. The complexity properties of its theoretical precursor, the NID, have been open. We show that the NID is neither upper semicomputable nor lower semicomputable up to any reasonable precision.

  12. Distance learning for similarity estimation

    NARCIS (Netherlands)

    Yu, J.; Amores, J.; Sebe, N.; Radeva, P.; Tian, Q.

    2008-01-01

    In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized

  13. Stereoscopic distance perception

    Science.gov (United States)

    Foley, John M.

    1989-01-01

    Limited cue, open-loop tasks in which a human observer indicates distances or relations among distances are discussed. By open-loop tasks, it is meant tasks in which the observer gets no feedback as to the accuracy of the responses. What happens when cues are added and when the loop is closed are considered. The implications of this research for the effectiveness of visual displays is discussed. Errors in visual distance tasks do not necessarily mean that the percept is in error. The error could arise in transformations that intervene between the percept and the response. It is argued that the percept is in error. It is also argued that there exist post-perceptual transformations that may contribute to the error or be modified by feedback to correct for the error.

  14. Distances to Dark Clouds: Comparing Extinction Distances to Maser Parallax Distances

    CERN Document Server

    Foster, Jonathan B; Benjamin, Robert A; Hoare, Melvin G; Jackson, James M

    2012-01-01

    We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near infrared (2MASS and UKIDSS) surveys. VLBI parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validatio...

  15. Sets avoiding integral distances

    CERN Document Server

    Kurz, Sascha

    2012-01-01

    We study open point sets in Euclidean spaces $\\mathbb{R}^d$ without a pair of points an integral distance apart. By a result of Furstenberg, Katznelson, and Weiss such sets must be of Lebesgue upper density zero. We are interested in how large such sets can be in $d$-dimensional volume. We determine the lower and upper bounds for the volumes of the sets in terms of the number of their connected components and dimension, and also give some exact values. Our problem can be viewed as a kind of inverse to known problems on sets with pairwise rational or integral distances.

  16. Distance Teaching on Bornholm

    DEFF Research Database (Denmark)

    Hansen, Finn J. S.; Clausen, Christian

    2001-01-01

    The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology and the organi......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...

  17. Distances to star forming regions

    CERN Document Server

    Loinard, Laurent

    2014-01-01

    The determination of accurate distances to star-forming regions are discussed in the broader historical context of astronomical distance measurements. We summarize recent results for regions within 1 kpc and present perspectives for the near and more distance future.

  18. Signaling Over Distances.

    Science.gov (United States)

    Saito, Atsushi; Cavalli, Valeria

    2016-02-01

    Neurons are extremely polarized cells. Axon lengths often exceed the dimension of the neuronal cell body by several orders of magnitude. These extreme axonal lengths imply that neurons have mastered efficient mechanisms for long distance signaling between soma and synaptic terminal. These elaborate mechanisms are required for neuronal development and maintenance of the nervous system. Neurons can fine-tune long distance signaling through calcium wave propagation and bidirectional transport of proteins, vesicles, and mRNAs along microtubules. The signal transmission over extreme lengths also ensures that information about axon injury is communicated to the soma and allows for repair mechanisms to be engaged. This review focuses on the different mechanisms employed by neurons to signal over long axonal distances and how signals are interpreted in the soma, with an emphasis on proteomic studies. We also discuss how proteomic approaches could help further deciphering the signaling mechanisms operating over long distance in axons. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Weighted Feature Distance

    DEFF Research Database (Denmark)

    Ortiz-Arroyo, Daniel; Yazdani, Hossein

    2017-01-01

    The accuracy of machine learning methods for clustering depends on the optimal selection of similarity functions. Conventional distance functions for the vector space might cause an algorithm to being affected by some dominant features that may skew its final results. This paper introduces a flexib...

  20. Encyclopedia of Distance Learning

    Science.gov (United States)

    Howard, Caroline, Ed.; Boettecher, Judith, Ed.; Justice, Lorraine, Ed.; Schenk, Karen, Ed.; Rogers, Patricia, Ed.; Berg, Gary, Ed.

    2005-01-01

    The innovations in computer and communications technologies combined with on-going needs to deliver educational programs to students regardless of their physical locations, have lead to the innovation of distance education programs and technologies. To keep up with recent developments in both areas of technologies and techniques related to…

  1. Accreditation of Distance Learning

    Science.gov (United States)

    Demirel, Ergün

    2016-01-01

    The higher education institutes aspire to gain reputation of quality having accreditation from internationally recognized awarding bodies. The accreditation leads and provides quality assurance for education. Although distance learning becomes a significant part of the education system in the 21st century, there is still a common opinion that the…

  2. Prospect of Distance Learning

    Science.gov (United States)

    Rahman, Monsurur; Karim, Reza; Byramjee, Framarz

    2015-01-01

    Many educational institutions in the United States are currently offering programs through distance learning, and that trend is rising. In almost all spheres of education a developing country like Bangladesh needs to make available the expertise of the most qualified faculty to her distant people. But the fundamental question remains as to whether…

  3. Rapport in Distance Education

    Science.gov (United States)

    Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.

    2012-01-01

    Rapport has been recognized as important in learning in general but little is known about its importance in distance education (DE). The study we report on in this paper provides insights into the importance of rapport in DE as well as challenges to and indicators of rapport-building in DE. The study relied on interviews with 42 Canadian…

  4. Misconceptions of Astronomical Distances

    Science.gov (United States)

    Miller, Brian W.; Brewer, William F.

    2010-01-01

    Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…

  5. Learning Styles and Satisfaction in Distance Education

    Science.gov (United States)

    Wu, Darren C.

    2014-01-01

    Although complex, controversial, and contradicting, learning styles is highly influential. Distance education (DE) has experienced tremendous growth in the last few decades. The popularity of learning styles and DE necessitates research. This correlational research study was conducted to determine if there is any evidence to incorporate learning…

  6. Fuzzy clustering with Minkowski distance

    NARCIS (Netherlands)

    P.J.F. Groenen (Patrick); U. Kaymak (Uzay); J.M. van Rosmalen (Joost)

    2006-01-01

    textabstractDistances in the well known fuzzy c-means algorithm of Bezdek (1973) are measured by the squared Euclidean distance. Other distances have been used as well in fuzzy clustering. For example, Jajuga (1991) proposed to use the L_1-distance and Bobrowski and Bezdek (1991) also used the L_inf

  7. The sound of distance.

    Science.gov (United States)

    Rabaglia, Cristina D; Maglio, Sam J; Krehm, Madelaine; Seok, Jin H; Trope, Yaacov

    2016-07-01

    Human languages may be more than completely arbitrary symbolic systems. A growing literature supports sound symbolism, or the existence of consistent, intuitive relationships between speech sounds and specific concepts. Prior work establishes that these sound-to-meaning mappings can shape language-related judgments and decisions, but do their effects generalize beyond merely the linguistic and truly color how we navigate our environment? We examine this possibility, relating a predominant sound symbolic distinction (vowel frontness) to a novel associate (spatial proximity) in five studies. We show that changing one vowel in a label can influence estimations of distance, impacting judgment, perception, and action. The results (1) provide the first experimental support for a relationship between vowels and spatial distance and (2) demonstrate that sound-to-meaning mappings have outcomes that extend beyond just language and can - through a single sound - influence how we perceive and behave toward objects in the world. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Tolman's Luminosity-Distance, Poincare's Light-Distance and Cayley-Klein's Hyperbolic Distance

    CERN Document Server

    Pierseaux, Yves

    2009-01-01

    We deduce Tolman's formula of luminosity-distance in Cosmology from Poincare's definition of light-distance with Lorentz Transformation (LT).In Minkowskian metric, if distance is proper time (as it is often argued) then light-distance must be also the shortest distance, like proper duration (unlike Einstein's longest length within rest system). By introducing Poincare's proper light-distance in Einstein's basic synchronization we deduce a dilated distance between observer and receding mirror (with relativistic Doppler factor). Such a distance corresponds not to an Euclidean distance (Einstein's rigid rod) but to an Hyperbolic distance (Cayley-Klein) with a Lobatchevskian Horizon. From a basic proportionality hyperbolic distance-velocity, we deduce the law of Hubble. By following Penrose's Lobatchevskian representation of LT, we transform Special Relativity (SR) into an Hyperbolic Cosmological Relativity (HCR). by using only the LT but the whole LT. In Hyperbolic Rotation motion (basic active LT or Einstein's ...

  9. Distance, Borders, and Time

    DEFF Research Database (Denmark)

    Skillicorn, David; Walther, Olivier; Zheng, Quan

    is a combination of the physical geography of the target environment, and the mental and physical cost of following a seemingly random pattern of attacks. Focusing on the distance and time between attacks and taking into consideration the transaction costs that state boundaries impose, we wish to understand what......” of North and West Africa that depicts the permeability to violence. A better understanding of how location, time, and borders condition attacks enables planning, prepositioning, and response....

  10. Biophysical characterization of the b-HLH-LZ of ΔMax, an alternatively spliced isoform of Max found in tumor cells: Towards the validation of a tumor suppressor role for the Max homodimers

    Science.gov (United States)

    Maltais, Loïka; Montagne, Martin; Bédard, Mikaël; Tremblay, Cynthia; Soucek, Laura

    2017-01-01

    It is classically recognized that the physiological and oncogenic functions of Myc proteins depend on specific DNA binding enabled by the dimerization of its C-terminal basic-region-Helix-Loop-Helix-Leucine Zipper (b-HLH-LZ) domain with that of Max. However, a new paradigm is emerging, where the binding of the c-Myc/Max heterodimer to non-specific sequences in enhancers and promoters drives the transcription of genes involved in diverse oncogenic programs. Importantly, Max can form a stable homodimer even in the presence of c-Myc and bind DNA (specific and non-specific) with comparable affinity to the c-Myc/Max heterodimer. Intriguingly, alterations in the Max gene by germline and somatic mutations or changes in the gene product by alternative splicing (e.g. ΔMax) were recently associated with pheochromocytoma and glioblastoma, respectively. This has led to the proposition that Max is, by itself, a tumor suppressor. However, the actual mechanism through which it exerts such an activity remains to be elucidated. Here, we show that contrary to the WT motif, the b-HLH-LZ of ΔMax does not homodimerize in the absence of DNA. In addition, although ΔMax can still bind the E-box sequence as a homodimer, it cannot bind non-specific DNA in that form, while it can heterodimerize with c-Myc and bind E-box and non-specific DNA as a heterodimer with high affinity. Taken together, our results suggest that the WT Max homodimer is important for attenuating the binding of c-Myc to specific and non-specific DNA, whereas ΔMax is unable to do so. Conversely, the splicing of Max into ΔMax could provoke an increase in overall chromatin bound c-Myc. According to the new emerging paradigm, the splicing event and the stark reduction in homodimer stability and DNA binding should promote tumorigenesis impairing the tumor suppressor activity of the WT homodimer of Max. PMID:28350847

  11. Normalized Compression Distance of Multiples

    CERN Document Server

    Cohen, Andrew R

    2012-01-01

    Normalized compression distance (NCD) is a parameter-free similarity measure based on compression. The NCD between pairs of objects is not sufficient for all applications. We propose an NCD of finite multisets (multiples) of objacts that is metric and is better for many applications. Previously, attempts to obtain such an NCD failed. We use the theoretical notion of Kolmogorov complexity that for practical purposes is approximated from above by the length of the compressed version of the file involved, using a real-world compression program. We applied the new NCD for multiples to retinal progenitor cell questions that were earlier treated with the pairwise NCD. Here we get significantly better results. We also applied the NCD for multiples to synthetic time sequence data. The preliminary results are as good as nearest neighbor Euclidean classifier.

  12. Monge Distance between Quantum States

    CERN Document Server

    Zyczkowski, K; Zyczkowski, Karol; Slomczynski, Wojciech

    1998-01-01

    We define a metric in the space of quantum states taking the Monge distance between corresponding Husimi distributions (Q--functions). This quantity fulfills the axioms of a metric and satisfies the following semiclassical property: the distance between two coherent states is equal to the Euclidean distance between corresponding points in the classical phase space. We compute analytically distances between certain states (coherent, squeezed, Fock and thermal) and discuss a scheme for numerical computation of Monge distance for two arbitrary quantum states.

  13. Regularisation of 3D Signed Distance Fields

    DEFF Research Database (Denmark)

    Paulsen, Rasmus Reinhold; Bærentzen, Jakob Andreas; Larsen, Rasmus

    2009-01-01

    Signed 3D distance fields are used a in a variety of domains. From shape modelling to surface registration. They are typically computed based on sampled point sets. If the input point set contains holes, the behaviour of the zero-level surface of the distance field is not well defined...... Cholesky factorisation. It is demonstrated that the zero-level surface will act as a membrane after the proposed regularisation. This effectively closes holes in a predictable way. Finally, the performance of the method is tested with a set of synthetic point clouds of increasing complexity....

  14. The DDO IVC Distance Project

    CERN Document Server

    Gladders, M D; Burns, C R; Attard, A; Casey, M P; Hamilton, D; Mallén-Ornelas, G; Karr, J L; Poirier, S M; Sawicki, M; Barrientos, F; Barkhouse, W A; Brodwin, M; Clark, J; McNaughton, R; Ruetalo-Pacheco, M; Mochnacki, S W; Gladders, Michael D.; Clarke, Tracy E.; Burns, Christopher R.; Attard, Allen; Casey, Michael P.; Hamilton, Devon; Mallen-Ornelas, Gabriela; Karr, Jennifer L.; Poirier, Sara M.; Sawicki, Marcin; Barrientos, Felipe; Barkhouse, Wayne; Brodwin, Mark; Clark, Jason; Naughton, Rosemary Mc; Ruetalo-Pacheco, Marcelo; Mochnacki, Stefan W.

    1998-01-01

    We present the first set of distance limits from the David Dunlap Observatory Intermediate Velocity Cloud (DDO IVC) distance project. Such distance measures are crucial to understanding the origins and dynamics of IVCs, as the distances set most of the basic physical parameters for the clouds. Currently there are very few IVCs with reliably known distances. This paper describes in some detail the basic techniques used to measure distances, with particular emphasis on the the analysis of interstellar absorption line data, which forms the basis of our distance determinations. As an example, we provide a detailed description of our distance determination for the Draco Cloud. Preliminary distance limits for a total of eleven clouds are provided.

  15. Advanced hierarchical distance sampling

    Science.gov (United States)

    Royle, Andy

    2016-01-01

    In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.

  16. Distance Metric Tracking

    Science.gov (United States)

    2016-03-02

    520, 2004. 16 [12] E.C. Hall and R.M. Willett. Online convex optimization in dynamic environ- ments. Selected Topics in Signal Processing, IEEE Journal...Conference on Machine Learning, pages 1160–1167. ACM, 2008. [25] Eric P Xing, Michael I Jordan, Stuart Russell, and Andrew Y Ng. Distance metric...whereBψ is any Bregman divergence and ηt is the learning rate parameter. From ( Hall & Willett, 2015) we have: Theorem 1. G` = max θ∈Θ,`∈L ‖∇f(θ)‖ φmax = 1

  17. Long distance tunneling

    CERN Document Server

    Ivlev, B I

    2005-01-01

    Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. A periodic structure of the wave function is formed in the direction joining the wells. The resulting motion can be coherent like motion in a conventional narrow band periodic structure. A particle penetrates the barrier over a long distance which strongly contrasts to WKB-like tunneling. The whole problem is stationary. The coherent process can be influenced by dissipation.

  18. Distances on Lozenge Tilings

    CERN Document Server

    Bodini, Olivier; Fernique, Thomas

    2009-01-01

    In this paper, a structural property of the set of lozenge tilings of a 2n-gon is highlighted. We introduce a simple combinatorial value called Hamming-distance, which is a lower bound for the flipdistance (i.e. the number of necessary local transformations involving three lozenges) between two given tilings. It is here proven that, for n5, We show that there is some deficient pairs of tilings for which the flip connection needs more flips than the combinatorial lower bound indicates.

  19. Distance Teaching on Bornholm

    DEFF Research Database (Denmark)

    Hansen, Finn J. S.; Clausen, Christian

    2001-01-01

    and the organisational set-up. It is debated which kind of social learning that has taken place. The innovation process was based on the implementation of an inflexible video-conference system without any proactive considerations of organisational change or pedagocical development. User appropriation of the technology......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...

  20. Distance Learning. Volume I: Distance Learning Analysis Study.

    Science.gov (United States)

    1998-09-01

    The primary focus of this project is the determination of the feasibility and cost effectiveness of applying Distance Learning strategies to 22...selected PPSCP courses and development of a Distance Learning Analysis Procedures Manual.

  1. PERBANDINGAN EUCLIDEAN DISTANCE DENGAN CANBERRA DISTANCE PADA FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    Sendhy Rachmat Wurdianarto

    2014-08-01

    Full Text Available Perkembangan ilmu pada dunia komputer sangatlah pesat. Salah satu yang menandai hal ini adalah ilmu komputer telah merambah pada dunia biometrik. Arti biometrik sendiri adalah karakter-karakter manusia yang dapat digunakan untuk membedakan antara orang yang satu dengan yang lainnya. Salah satu pemanfaatan karakter / organ tubuh pada setiap manusia yang digunakan untuk identifikasi (pengenalan adalah dengan memanfaatkan wajah. Dari permasalahan diatas dalam pengenalan lebih tentang aplikasi Matlab pada Face Recognation menggunakan metode Euclidean Distance dan Canberra Distance. Model pengembangan aplikasi yang digunakan adalah model waterfall. Model waterfall beriisi rangkaian aktivitas proses yang disajikan dalam proses analisa kebutuhan, desain menggunakan UML (Unified Modeling Language, inputan objek gambar diproses menggunakan Euclidean Distance dan Canberra Distance. Kesimpulan yang dapat ditarik adalah aplikasi face Recognation menggunakan metode euclidean Distance dan Canverra Distance terdapat kelebihan dan kekurangan masing-masing. Untuk kedepannya aplikasi tersebut dapat dikembangkan dengan menggunakan objek berupa video ataupun objek lainnya.   Kata kunci : Euclidean Distance, Face Recognition, Biometrik, Canberra Distance

  2. Minimal distances between SCFTs

    Energy Technology Data Exchange (ETDEWEB)

    Buican, Matthew [Department of Physics and Astronomy, Rutgers University,Piscataway, NJ 08854 (United States)

    2014-01-28

    We study lower bounds on the minimal distance in theory space between four-dimensional superconformal field theories (SCFTs) connected via broad classes of renormalization group (RG) flows preserving various amounts of supersymmetry (SUSY). For N=1 RG flows, the ultraviolet (UV) and infrared (IR) endpoints of the flow can be parametrically close. On the other hand, for RG flows emanating from a maximally supersymmetric SCFT, the distance to the IR theory cannot be arbitrarily small regardless of the amount of (non-trivial) SUSY preserved along the flow. The case of RG flows from N=2 UV SCFTs is more subtle. We argue that for RG flows preserving the full N=2 SUSY, there are various obstructions to finding examples with parametrically close UV and IR endpoints. Under reasonable assumptions, these obstructions include: unitarity, known bounds on the c central charge derived from associativity of the operator product expansion, and the central charge bounds of Hofman and Maldacena. On the other hand, for RG flows that break N=2→N=1, it is possible to find IR fixed points that are parametrically close to the UV ones. In this case, we argue that if the UV SCFT possesses a single stress tensor, then such RG flows excite of order all the degrees of freedom of the UV theory. Furthermore, if the UV theory has some flavor symmetry, we argue that the UV central charges should not be too large relative to certain parameters in the theory.

  3. Symbolic Dynamics Complexity Information Based Detection of Ventricular Tachycardia and Fibrillation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hongxuan; ZHU Yisheng; XU Yuhong; WANG Ziming

    2001-01-01

    On the base of applied symbolic dynamics, this paper, utilizing L-Z complexity measure,forwarded a new definition of information complexity rate: cc(n). Using such definition, we obtained some relative properties to help identify periodical, random and chaotic process accurately. Applying to complexity analysis in abnormal ECG, we confirmed the reasonability of this information complexity and complexity rate approach, by means of biological experiments and computer simulations. At last, objective analysis and explanations of the mechanism of VT and VF were reported. The results indicated: with the help of complexity measure and complexity rate, we can achieve recognition of VT (Ventricular Tachycardia)and VF (Ventricular Fibrillation) up to 100%.

  4. The Distance to M51

    CERN Document Server

    McQuinn, Kristen B W; Dolphin, Andrew E; Berg, Danielle; Kennicutt, Robert

    2016-01-01

    Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51 - the Whirlpool galaxy - from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58+/-0.10 Mpc (statistical), corresponding to a distance modulus of 29.67+/-0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement unce...

  5. Comparative DNA binding abilities and phosphatase-like activities of mono-, di-, and trinuclear Ni(II) complexes: the influence of ligand denticity, metal-metal distance, and coordinating solvent/anion on kinetics studies.

    Science.gov (United States)

    Bhardwaj, Vimal K; Singh, Ajnesh

    2014-10-06

    Six novel Ni(II) complexes, namely, [Ni2(HL(1))(OAc)2] (1), [Ni3L(1)2]·H2O·2CH3CN (2), [Ni2(L(2))(L(3))(CH3CN)] (3), [Ni2(L(2))2(H2O)2] (4), [Ni2(L(2))2(DMF)2]2·2H2O (5), and [Ni(HL(2))2]·H2O (6), were synthesized by reacting nitrophenol-based tripodal (H3L(1)) and dipodal (H2L(2)) Schiff base ligands with Ni(II) metal salts at ambient conditions. All the complexes were fully characterized with different spectroscopic techniques such as elemental analyses, IR, UV-vis spectroscopy, and electrospray ionization mass spectrometry. The solid-state structures of 2, 3, 5, and 6 were determined using single-crystal X-ray crystallography. The compounds 1, 3, 4, and 5 are dinuclear complexes where the two Ni(II) centers have octahedral geometry with bridging phenoxo groups. Compound 2 is a trinuclear complex with two different types of Ni(II) centers. In compound 3 one of the Ni(II) centers has a coordinated acetonitrile molecule, whereas in compound 4, a water molecule has occupied one coordination site of each Ni(II) center. In complex 5, the coordinated water of complex 4 was displaced by the dimethylformamide (DMF) during its crystallization. Complex 6 is mononuclear with two amine-bis(phenolate) ligands in scissorlike fashion around the Ni(II) metal center. The single crystals of 1 and 4 could not be obtained; however, from the spectroscopic data and physicochemical properties (electronic and redox properties) it was assumed that the structures of these complexes are quite similar to other analogues. DNA binding abilities and phosphatase-like activities of all characterized complexes were also investigated. The ligand denticity, coordinated anions/solvents (such as acetate, acetonitrile, water, and DMF), and cooperative action of two metal centers play a significant role in the phosphate ester bond cleavage of 2-hydroxypropyl-p-nitropenylphosphate by transesterification mechanism. Complex 3 exhibits highest activity among complexes 1-6 with 3.86 × 10(5) times

  6. Improved directional-distance filter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper proposes a new spatial-distance weighting function.By combining the weighting function and the traditional directional-distance filter (DDF) in a novel way,a new vector filter-the adaptive distance-weighted directional-distance filter (ADWDDF)-is presented.The experimental results show that the proposed solution provides better filtering performance and preserves better image chromaticity and edge or detail information compared with the traditional DDF and some other typical vector filters.

  7. Isolation by distance, web service

    OpenAIRE

    Bohonak Andrew J; Jensen Jeffrey L; Kelley Scott T

    2005-01-01

    Abstract Background The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. Results We have created Isolation by Distance Web Service (IBDWS) a user-friendly web interface for determining patterns of isolation by distance. Using this site, ...

  8. Reconsidering Moore's Transactional Distance Theory

    Science.gov (United States)

    Giossos, Yiannis; Koutsouba, Maria; Lionarakis, Antonis; Skavantzos, Kosmas

    2009-01-01

    One of the core theories of distance education is Michael Graham Moore's "Theory of Transactional Distance" that provides the broad framework of the pedagogy of distance education and allows the generation of almost infinite number of hypotheses for research. However, the review of the existing studies relating to the theory showed the use of a…

  9. Algorithms for Speeding up Distance-Based Outlier Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — The problem of distance-based outlier detection is difficult to solve efficiently in very large datasets because of potential quadratic time complexity. We address...

  10. Absolute Orientation Based on Distance Kernel Functions

    Directory of Open Access Journals (Sweden)

    Yanbiao Sun

    2016-03-01

    Full Text Available The classical absolute orientation method is capable of transforming tie points (TPs from a local coordinate system to a global (geodetic coordinate system. The method is based only on a unique set of similarity transformation parameters estimated by minimizing the total difference between all ground control points (GCPs and the fitted points. Nevertheless, it often yields a transformation with poor accuracy, especially in large-scale study cases. To address this problem, this study proposes a novel absolute orientation method based on distance kernel functions, in which various sets of similarity transformation parameters instead of only one set are calculated. When estimating the similarity transformation parameters for TPs using the iterative solution of a non-linear least squares problem, we assigned larger weighting matrices for the GCPs for which the distances from the point are short. The weighting matrices can be evaluated using the distance kernel function as a function of the distances between the GCPs and the TPs. Furthermore, we used the exponential function and the Gaussian function to describe distance kernel functions in this study. To validate and verify the proposed method, six synthetic and two real datasets were tested. The accuracy was significantly improved by the proposed method when compared to the classical method, although a higher computational complexity is experienced.

  11. Refocusing distance of a standard plenoptic camera.

    Science.gov (United States)

    Hahne, Christopher; Aggoun, Amar; Velisavljevic, Vladan; Fiebig, Susanne; Pesch, Matthias

    2016-09-19

    Recent developments in computational photography enabled variation of the optical focus of a plenoptic camera after image exposure, also known as refocusing. Existing ray models in the field simplify the camera's complexity for the purpose of image and depth map enhancement, but fail to satisfyingly predict the distance to which a photograph is refocused. By treating a pair of light rays as a system of linear functions, it will be shown in this paper that its solution yields an intersection indicating the distance to a refocused object plane. Experimental work is conducted with different lenses and focus settings while comparing distance estimates with a stack of refocused photographs for which a blur metric has been devised. Quantitative assessments over a 24 m distance range suggest that predictions deviate by less than 0.35 % in comparison to an optical design software. The proposed refocusing estimator assists in predicting object distances just as in the prototyping stage of plenoptic cameras and will be an essential feature in applications demanding high precision in synthetic focus or where depth map recovery is done by analyzing a stack of refocused photographs.

  12. Is Distance Dead?

    DEFF Research Database (Denmark)

    Battiston, Diego; Blanes i Vidal, Jordi; Kirchmaier, Tom

    Has technology made face-to-face communication redundant? We investigate using a natural experiment in an organisation where a worker must communicate complex electronic information to a colleague. Productivity is higher when the teammates are (exogenously) in the same room and, inside the room, ...

  13. Distance learning and perioperative nursing.

    Science.gov (United States)

    Gruendemann, Barbara J

    2007-03-01

    Distance learning in nursing education is arriving with unprecedented speed, which has led to much uncertainty among educators. This article provides an overview of distance learning and its application to perioperative nursing. Lack of face-to-face interaction is of foremost concern in distance learning, and educators must develop new teaching strategies to address this problem. Models for assessing outcomes and effectiveness are important tools to use when implementing a distance learning program. Basic perioperative nursing concepts, skills, procedures, and recommended practices can be introduced effectively with online distance learning modalities and then reinforced through a clinical component.

  14. Elucidation of the structural determinants responsible for the specific formation of heterodimeric Mxd1/Max b-HLH-LZ and its binding to E-box sequences.

    Science.gov (United States)

    Montagne, Martin; Naud, Jean-François; Lavigne, Pierre

    2008-02-08

    The proteins of the Mxd family (formally known as Mad) are antagonists of the oncoprotein c-Myc. They compete with c-Myc for their obligate partner Max to prevent the c-Myc/Max heterodimer from binding to E-box sequences in the target gene promoters. In cancer cells, where Myc is overexpressed, the expression of Mxd proteins is usually insufficient or abrogated. However, the reintroduction of Mxd1 expression in these cells prevents growth and proliferation. While the antagonism of c-Myc functions by Mxd proteins is of potential relevance for the development of cancer treatment strategies, the structural determinants responsible for the specific heterodimerization between the Mxd and the Max b-helix-loop-helix-leucine zippers are not fully understood. Moreover, whether the heterodimer is assembled on DNA or in the nucleoplasm prior to DNA binding is under debate. In this article, we demonstrate that Mxd1 D112a and Max N78a and H81d, which are located in the leucine zippers of the proteins, can dictate the specificity of heterodimerization and whether or not the Mxd1/Max/DNA complex forms. Our results also indicate that additional specific determinants exist in the helix-loop-helix domains of Max and Mxd1. Finally, we provide evidence that heterodimerization must precede DNA binding in vivo.

  15. New distances to RAVE stars

    CERN Document Server

    Binney, James; Kordopatis, Georges; McMillan, Paul J; Sharma, Sanjib; Zwitter, Tomaz; Bienayme, Olivier; Bland-Hawthorn, Joss; Steinmetz, Matthias; Gilmore, Gerry; Williams, Mary E K; Navarro, Julio; Grebel, Eva K; Helmi, Amina; Parker, Quentin; Reid, Warren A; Seabroke, George; Watson, Fred; Wyse, Rosie F G

    2013-01-01

    Probability density functions are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N>=10. The expectation value of distance is larger than the distance implied by the expectation of distance modulus; the latter is itself larger than the distance implied by the expectation value of the parallax. Our parallaxes of Hipparcos stars agree well with the values measured by Hipparcos, so the expectation of parallax is the most reliable distance indicator. The latter are improved by taking extinction into account. We provide one- two- or three-Gaussian fits to the distance pdfs. The effective temperature absolute-magnitude diagram of our stars is significantly improved when these pdfs are used to make the diagram. We use the method of kinematic corrections devised by Schoenrich, Binney & Asplund to check for systematic errors in our estimators for ordinary stars and confirm the conclusion reached from the Hipparcos s...

  16. Random matrix approach to the distribution of genomic distance.

    Science.gov (United States)

    Alexeev, Nikita; Zograf, Peter

    2014-08-01

    The cycle graph introduced by Bafna and Pevzner is an important tool for evaluating the distance between two genomes, that is, the minimal number of rearrangements needed to transform one genome into another. We interpret this distance in topological terms and relate it to the random matrix theory. Namely, the number of genomes at a given 2-break distance from a fixed one (the Hultman number) is represented by a coefficient in the genus expansion of a matrix integral over the space of complex matrices with the Gaussian measure. We study generating functions for the Hultman numbers and prove that the two-break distance distribution is asymptotically normal.

  17. Fast computation of distance estimators

    Directory of Open Access Journals (Sweden)

    Lagergren Jens

    2007-03-01

    Full Text Available Abstract Background Some distance methods are among the most commonly used methods for reconstructing phylogenetic trees from sequence data. The input to a distance method is a distance matrix, containing estimated pairwise distances between all pairs of taxa. Distance methods themselves are often fast, e.g., the famous and popular Neighbor Joining (NJ algorithm reconstructs a phylogeny of n taxa in time O(n3. Unfortunately, the fastest practical algorithms known for Computing the distance matrix, from n sequences of length l, takes time proportional to l·n2. Since the sequence length typically is much larger than the number of taxa, the distance estimation is the bottleneck in phylogeny reconstruction. This bottleneck is especially apparent in reconstruction of large phylogenies or in applications where many trees have to be reconstructed, e.g., bootstrapping and genome wide applications. Results We give an advanced algorithm for Computing the number of mutational events between DNA sequences which is significantly faster than both Phylip and Paup. Moreover, we give a new method for estimating pairwise distances between sequences which contain ambiguity Symbols. This new method is shown to be more accurate as well as faster than earlier methods. Conclusion Our novel algorithm for Computing distance estimators provides a valuable tool in phylogeny reconstruction. Since the running time of our distance estimation algorithm is comparable to that of most distance methods, the previous bottleneck is removed. All distance methods, such as NJ, require a distance matrix as input and, hence, our novel algorithm significantly improves the overall running time of all distance methods. In particular, we show for real world biological applications how the running time of phylogeny reconstruction using NJ is improved from a matter of hours to a matter of seconds.

  18. Distance learning for similarity estimation.

    Science.gov (United States)

    Yu, Jie; Amores, Jaume; Sebe, Nicu; Radeva, Petia; Tian, Qi

    2008-03-01

    In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized variants according to the Maximum Likelihood theory. These measures can provide a more accurate feature model than the classical Euclidean and Manhattan distances. We also find that the feature elements are often from heterogeneous sources that may have different influence on similarity estimation. Therefore, the assumption of single isotropic distribution model is often inappropriate. To alleviate this problem, we use a boosted distance measure framework that finds multiple distance measures which fit the distribution of selected feature elements best for accurate similarity estimation. The new distance measures for similarity estimation are tested on two applications: stereo matching and motion tracking in video sequences. The performance of boosted distance measure is further evaluated on several benchmark data sets from the UCI repository and two image retrieval applications. In all the experiments, robust results are obtained based on the proposed methods.

  19. Distance-weighted city growth.

    Science.gov (United States)

    Rybski, Diego; García Cantú Ros, Anselmo; Kropp, Jürgen P

    2013-04-01

    Urban agglomerations exhibit complex emergent features of which Zipf's law, i.e., a power-law size distribution, and fractality may be regarded as the most prominent ones. We propose a simplistic model for the generation of citylike structures which is solely based on the assumption that growth is more likely to take place close to inhabited space. The model involves one parameter which is an exponent determining how strongly the attraction decays with the distance. In addition, the model is run iteratively so that existing clusters can grow (together) and new ones can emerge. The model is capable of reproducing the size distribution and the fractality of the boundary of the largest cluster. Although the power-law distribution depends on both, the imposed exponent and the iteration, the fractality seems to be independent of the former and only depends on the latter. Analyzing land-cover data, we estimate the parameter-value γ≈2.5 for Paris and its surroundings.

  20. Application of distances between terms for flat and hierarchical data

    CERN Document Server

    Bedoya-Puerta, Jorge-Alonso

    2011-01-01

    In machine learning, distance-based algorithms, and other approaches, use information that is represented by propositional data. However, this kind of representation can be quite restrictive and, in many cases, it requires more complex structures in order to represent data in a more natural way. Terms are the basis for functional and logic programming representation. Distances between terms are a useful tool not only to compare terms, but also to determine the search space in many of these applications. This dissertation applies distances between terms, exploiting the features of each distance and the possibility to compare from propositional data types to hierarchical representations. The distances between terms are applied through the k-NN (k-nearest neighbor) classification algorithm using XML as a common language representation. To be able to represent these data in an XML structure and to take advantage of the benefits of distance between terms, it is necessary to apply some transformations. These transf...

  1. DISTANCE EDUCATOR: A Multiskill Personality

    Directory of Open Access Journals (Sweden)

    Sangeeta MALIK

    2013-01-01

    Full Text Available When we talk about a distance educator and a conventional educator the difference we found nd about both of them is that, a distance educator needs to play multiple roles as compared to a conventional educator. They require more skills and knowledge cater to the needs of the learner. In this article we will cover all the responsible areas of a distance educator & why we should consider them as a multiskill personality?

  2. Doctoral education from a distance.

    Science.gov (United States)

    Effken, Judith A

    2008-12-01

    This article describes the environmental factors that have contributed to the recent rapid growth of nursing doctoral education at a distance. Early and recent efforts to deliver distance doctoral education are discussed, using The University of Arizona College of Nursing experience as the key exemplar. The Community of Inquiry model is introduced as an appropriate model for doctoral education and then used as a framework to evaluate the current state of the art in distance doctoral nursing education. Successes and challenges in delivering doctoral education from a distance are described.

  3. The Extended Edit Distance Metric

    CERN Document Server

    Fuad, Muhammad Marwan Muhammad

    2007-01-01

    Similarity search is an important problem in information retrieval. This similarity is based on a distance. Symbolic representation of time series has attracted many researchers recently, since it reduces the dimensionality of these high dimensional data objects. We propose a new distance metric that is applied to symbolic data objects and we test it on time series data bases in a classification task. We compare it to other distances that are well known in the literature for symbolic data objects. We also prove, mathematically, that our distance is metric.

  4. Transactional Distance and Autonomy in a Distance Learning Environment

    Science.gov (United States)

    Vasiloudis, G.; Koutsouba, M.; Giossos, Y.; Mavroidis, I.

    2015-01-01

    This paper studies the transactional distance between the students and the tutor as well as the autonomy of students in a postgraduate course of the Hellenic Open University (HOU). The aim of the paper is to examine how the relation between autonomy and transactional distance evolves during an academic year and how this relation is affected by…

  5. Distance spectra and Distance energy of Integral Circulant Graphs

    CERN Document Server

    c, Aleksandar Ili\\'

    2011-01-01

    The distance energy of a graph $G$ is a recently developed energy-type invariant, defined as the sum of absolute values of the eigenvalues of the distance matrix of $G$. There was a vast research for the pairs and families of non-cospectral graphs having equal distance energy, and most of these constructions were based on the join of graphs. A graph is called circulant if it is Cayley graph on the circulant group, i.e. its adjacency matrix is circulant. A graph is called integral if all eigenvalues of its adjacency matrix are integers. Integral circulant graphs play an important role in modeling quantum spin networks supporting the perfect state transfer. In this paper, we characterize the distance spectra of integral circulant graphs and prove that these graphs have integral eigenvalues of distance matrix $D$. Furthermore, we calculate the distance spectra and distance energy of unitary Cayley graphs. In conclusion, we present two families of pairs $(G_1, G_2)$ of integral circulant graphs with equal distanc...

  6. COLLABORATIVE LEARNING PERSPECTIVE OF DISTANCE EDUCATION WITHOUT

    Directory of Open Access Journals (Sweden)

    Delaine Gibeli Viana

    2012-12-01

    Full Text Available INTRODUCTION: We propose to introduce collaborative learning as a teaching strategy resulting from social interactions and advancement of NTICs that, being in constant improvement is shown by the breakdown of complex paradigms that imposes involved in distance education. OBJECTIVE: To understand the socialization of knowledge leads us to a collaborative learning and distance education provides the knowledge socialization, without a perspective of distance education, in order to show the distance through the commitment and interface technology present in this mode, making a challenge for the educator effective the learning process. METHODOLOGY: This is a literature review of analytical and documentary form, of a qualitative nature. RESULT: with the new ICTs, the possibilities for learning in different contexts in virtual learning environments, raise questions about how to study it. Learning changes with the construction of knowledge that is dynamic and shared, enabling new forms of practice education, enhancing students' skills through cooperation and collaboration. Subjects that will lead us to reflect in this paper that underlie the subject enabling future research to be a constantly building and updating.

  7. 1D polymeric copper(I) complex [Cu2(μ-(2,6-Cl-ba)2en)(μ-I)2]n with exceptionally short Cusbnd Cu distance: Synthesis, characterization, thermal study and crystal structure

    Science.gov (United States)

    Khalaji, Aliakbar Dehno; Peyghoun, Seyyed Javad; Akbari, Alireza; Feizi, Nourollah; Dusek, Michal; Eigner, Vaclav

    2017-01-01

    A new 1D polymeric three coordinated copper(I) complex, [Cu2(μ-(2,6-Cl-ba)2en)(μ-I)2]n, with the bidentate Schiff base ligand N,N‧-bis(2,6-dichlorobenzylidene)ethane-1,2-diamine containing a flexible spacer (dbnd NCH2sbnd CH2sbnd Ndbnd) was synthesized and characterized by elemental analyses, UV-Vis, FT-IR and 1H NMR spectroscopy and thermal analaysis. Its molecular structure was determined by single-crystal X-ray diffraction and shows the (2,6-Cl-ba)2en acts as a bis-monodentate bridging ligand forming the dinuclear [Cu2(μ-(2,6-Cl-ba)2en)] groups. Such dinuclear groups are bridged by two iodine anions [(μ-I)2] to form a 1D polymeric copper(I) complex. The copper(I) ions are coordinated in a distorted trigonal planar geometry by two I atoms and one nitrogen atom of Schiff base ligand (2,6-Cl-ba)2en.

  8. Dependency distances in natural mixed languages. Comment on "Dependency distance: A new perspective on syntactic patterns in natural languages" by Haitao Liu et al.

    Science.gov (United States)

    Wang, Lin

    2017-07-01

    Haitao Liu et al.'s article [1] offers a comprehensive account of the diversity of syntactic patterns in human languages in terms of an important index of memory burden and syntactic difficulty - the dependency distance. Natural languages, a complex system, present overall shorter dependency distances under the universal pressure for dependency distance minimization; however, there exist some relatively-long-distance dependencies, which reflect that language can constantly adapt itself to some deep-level biological or functional constraints.

  9. Virtual Bioinformatics Distance Learning Suite

    Science.gov (United States)

    Tolvanen, Martti; Vihinen, Mauno

    2004-01-01

    Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…

  10. The Psychology of Psychic Distance

    DEFF Research Database (Denmark)

    Håkanson, Lars; Ambos, Björn; Schuster, Anja

    2016-01-01

    and their theoretical underpinnings assume psychic distances to be symmetric. Building on insights from psychology and sociology, this paper demonstrates how national factors and cognitive processes interact in the formation of asymmetric distance perceptions. The results suggest that exposure to other countries...

  11. The Distance to M104

    Science.gov (United States)

    McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

    2016-11-01

    M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully-Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  12. The Distance to M51

    Science.gov (United States)

    McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

    2016-07-01

    Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  13. Quality Content in Distance Education

    Science.gov (United States)

    Yildiz, Ezgi Pelin; Isman, Aytekin

    2016-01-01

    In parallel with technological advances in today's world of education activities can be conducted without the constraints of time and space. One of the most important of these activities is distance education. The success of the distance education is possible with content quality. The proliferation of e-learning environment has brought a need for…

  14. Virtual Bioinformatics Distance Learning Suite

    Science.gov (United States)

    Tolvanen, Martti; Vihinen, Mauno

    2004-01-01

    Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…

  15. Distance labeling schemes for trees

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben;

    2016-01-01

    We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoill...

  16. New distances to RAVE stars

    NARCIS (Netherlands)

    Binney, J.; Burnett, B.; Kordopatis, G.; McMillan, P. J.; Sharma, S.; Zwitter, T.; Bienayme, O.; Bland-Hawthorn, J.; Steinmetz, M.; Gilmore, G.; Williams, M. E. K.; Navarro, J.; Grebel, E. K.; Helmi, A.; Parker, Q.; Reid, W. A.; Seabroke, G.; Watson, F.; Wyse, R. F. G.

    Probability density functions (pdfs) are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N >= 10. Single-Gaussian fits to the pdf in distance modulus suffice for roughly half the stars, with most of

  17. Distance labeling schemes for trees

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben

    2016-01-01

    variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta...

  18. Faculty Attitudes about Distance Education

    Science.gov (United States)

    Smidt, Esther; McDyre, Brian; Bunk, Jennifer; Li, Rui; Gatenby, Tanya

    2014-01-01

    In recent years, there has been a dramatic increase in distance learning in higher education. Given this, it is extremely important to understand faculty attitudes about distance education, not only because they can vary widely, but also because it is the faculty, through their design and implementation of online courses, that will shape the…

  19. Distance-constrained grid colouring

    Directory of Open Access Journals (Sweden)

    Aszalós László

    2016-06-01

    Full Text Available Distance-constrained colouring is a mathematical model of the frequency assignment problem. This colouring can be treated as an optimization problem so we can use the toolbar of the optimization to solve concrete problems. In this paper, we show performance of distance-constrained grid colouring for two methods which are good in map colouring.

  20. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    Science.gov (United States)

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  1. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    Science.gov (United States)

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  2. Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

    Directory of Open Access Journals (Sweden)

    Florian eFort

    2015-02-01

    Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

  3. Distance labeling schemes for trees

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben

    2016-01-01

    We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoille...... variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta......(log(n)) bits for constant ε> 0. (1 + ε)-stretch labeling schemes with polylogarithmic label size have previously been established for doubling dimension graphs by Talwar [Talwar, STOC, 2004]. In addition, we present matching upper and lower bounds for distance labeling for caterpillars, showing that labels...

  4. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

    complexity of two of the most studied functions in the communication complexity literature: Gap Hamming Distance (GHD) and Inner Product mod 2 (IP). In our first result we affirm the conjecture that the information complexity of GHD is linear even under the uniform distribution. This strengthens the O(n) bound shown by Kerenidis et al. (2012) and answers an open problem by Chakrabarti et al. (2012). We also prove that the information complexity of IP is arbitrarily close to the trivial upper bound n as the permitted error tends to zero, again strengthening the O(n) lower bound proved by Braverman and Weinstein (2011). More importantly, our proofs demonstrate that self-reducibility makes the connection between information complexity and communication complexity lower bounds a two-way connection. Whereas numerous results in the past used information complexity techniques to derive new communication complexity lower bounds, we explore a generic way, in which communication complexity lower bounds imply information complexity lower bounds in a black-box manner. In the third contribution we consider the roles that private and public randomness play in the definition of information complexity. In communication complexity, private randomness can be trivially simulated by public randomness. Moreover, the communication cost of simulating public randomness with private randomness is well understood due to Newman's theorem (1991). In information complexity, the roles of public and private randomness are reversed: public randomness can be trivially simulated by private randomness. However, the information cost of simulating private randomness with public randomness is not understood. We show that protocols that use only public randomness admit a rather strong compression. In particular, efficient simulation of private randomness by public randomness would imply a version of a direct sum theorem in the setting of communication complexity. This establishes a yet another connection between

  5. Path integral distance for data interpretation

    CERN Document Server

    Volchenkov, D

    2015-01-01

    The process of data interpretation is always based on the implicit introduction of equivalence relations on the set of walks over the database. Every equivalence relation on the set of walks specifies a Markov chain describing the transitions of a discrete time random walk. In order to geometrize and interpret the data, we propose the new distance between data units defined as a "Feynman path integral", in which all possible paths between any two nodes in a graph model of the data are taken into account, although some paths are more preferable than others. Such a path integral distance approach to the analysis of databases has proven its efficiency and success, especially on multivariate strongly correlated data where other methods fail to detect structural components (urban planning, historical language phylogenies, music, street fashion traits analysis, etc. ). We believe that it would become an invaluable tool for the intelligent complexity reduction and big data interpretation.

  6. The Distance Field Model and Distance Constrained MAP Adaptation Algorithm

    Institute of Scientific and Technical Information of China (English)

    YUPeng; WANGZuoying

    2003-01-01

    Spatial structure information, i.e., the rel-ative position information of phonetic states in the feature space, is long to be carefully researched yet. In this pa-per, a new model named “Distance Field” is proposed to describe the spatial structure information. Based on this model, a modified MAP adaptation algorithm named dis-tance constrained maximum a poateriori (DCMAP) is in-troduced. The distance field model gives large penalty when the spatial structure is destroyed. As a result the DCMAP reserves the spatial structure information in adaptation process. Experiments show the Distance Field Model improves the performance of MAP adapta-tion. Further results show DCMAP has strong cross-state estimation ability, which is used to train a well-performed speaker-dependent model by data from only part of pho-

  7. The Distance to M104

    CERN Document Server

    McQuinn, Kristen B W; Dolphin, Andrew E; Berg, Danielle; Kennicutt, Robert

    2016-01-01

    M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch method. Our measurement yields the distance to M104 to be 9.55 +/- 0.13 +/- 0.31 Mpc equivalent to a distance modulus of 29.90 +/- 0.03 +/- 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully-Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measu...

  8. Reducing the distance in distance-caregiving by technology innovation

    Directory of Open Access Journals (Sweden)

    Lazelle E Benefield

    2007-07-01

    Full Text Available Lazelle E Benefield1, Cornelia Beck21College of Nursing, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; 2Pat & Willard Walker Family Memory Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USAAbstract: Family caregivers are responsible for the home care of over 34 million older adults in the United States. For many, the elder family member lives more than an hour’s distance away. Distance caregiving is a growing alternative to more familiar models where: 1 the elder and the family caregiver(s may reside in the same household; or 2 the family caregiver may live nearby but not in the same household as the elder. The distance caregiving model involves elders and their family caregivers who live at some distance, defined as more than a 60-minute commute, from one another. Evidence suggests that distance caregiving is a distinct phenomenon, differs substantially from on-site family caregiving, and requires additional assistance to support the physical, social, and contextual dimensions of the caregiving process. Technology-based assists could virtually connect the caregiver and elder and provide strong support that addresses the elder’s physical, social, cognitive, and/or sensory impairments. Therefore, in today’s era of high technology, it is surprising that so few affordable innovations are being marketed for distance caregiving. This article addresses distance caregiving, proposes the use of technology innovation to support caregiving, and suggests a research agenda to better inform policy decisions related to the unique needs of this situation.Keywords: caregiving, family, distance, technology, elders

  9. The Gould's Belt Distances Survey (GOBELINS) III. Distances and structure towards the Orion Molecular Clouds

    CERN Document Server

    Kounkel, Marina; Loinard, Laurent; Ortiz-León, Gisela N; Mioduszewski, Amy J; Rodríguez, Luis F; Dzib, Sergio A; Torres, Rosa M; Pech, Gerardo; Galli, Phillip A B; Rivera, Juana L; Boden, Andrew F; Evans, Neal J; Briceño, Cesar; Tobin, John J

    2016-01-01

    We present the results of the Gould's Belt Distances Survey (GOBELINS) of young star forming regions towards the Orion Molecular Cloud Complex. We detected 36 YSOs with the Very Large Baseline Array (VLBA), 27 of which have been observed in at least 3 epochs over the course of 2 years. At least half of these YSOs belong to multiple systems. We obtained parallax and proper motions towards these stars to study the structure and kinematics of the Complex. We measured a distance of 388$\\pm$5 pc towards the Orion Nebula Cluster, 428$\\pm$10 pc towards the southern portion L1641, 388$\\pm$10 pc towards NGC 2068, and roughly $\\sim$420 pc towards NGC 2024. Finally, we observed a strong degree of plasma radio scattering towards $\\lambda$ Ori.

  10. Distance and hospitality: reflexions on spatial reasoning

    Directory of Open Access Journals (Sweden)

    Juan de la Haba Morales

    2004-05-01

    Full Text Available In this paper we reconsider some of the ways in which the relation between space and society has been formulated. We focus specially on socioculturally mixed urban environments. We offer a three-part critique of what we call "spatial reasoning". That is, we critique the way of conceiving space-society relations which not only eliminates the social dimension (and so obscures relations and social positioning, but also hinders the appreciation of the multiplicity of ordinary social practices of exchange, transaction, communication or hospitality - which obscures, in a word, recognition between social groups. We conclude our argument by emphasising the complex relation between distance and hospitality.

  11. Distance Learning for Special Populations

    Science.gov (United States)

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  12. ECONOMICS OF DISTANCE EDUCATION RECONSIDERED

    Directory of Open Access Journals (Sweden)

    Wolfram LAASER

    2008-07-01

    Full Text Available ABSTRACT According to Gartner a certain hype of e-Learning was followed by a downturn but eLearning will continue to be an important factor in learning scenarios. However the economic viability of e-learning projects will be questioned with more scrutiny than in earlier periods. Therefore it seems to be a good opportunity to see what can be learned from past experience in costing distance learning projects and what aspects are added by current attempts to measure economic efficiency. After reviewing early research about costing distance learning some more recent approaches will be discussed, such as eLearning ROI-calculators and the concept of total cost of ownership. Furthermore some microeconomic effects referring to localization of distance learning courses are outlined. Finally several unsolved issues in costing distance education are summarized.

  13. Distance Education in Technological Age

    Directory of Open Access Journals (Sweden)

    R .C. SHARMA

    2005-04-01

    Full Text Available Distance Education in Technological AgeRomesh Verma (Editor, New Delhi: Anmol Publications, 2005, ISBN 81-261-2210-2, pp. 419 Reviewed by R C SHARMARegional DirectorIndira Gandhi National Open University-INDIA The advancements in information and communication technologies have brought significant changes in the way the open and distance learning are provided to the learners. The impact of such changes is quite visible in both developed and developing countries. Switching over to online mode, joining hands with private initiatives and making a presence in foreign waters, are some of the hallmarks of the open and distance education (ODE institutions in developing countries. The compilation of twenty six essays on themes as applicable to ODE has resulted in the book, “Distance Education in Technological Age”. These essays follow a progressive style of narration, starting from describing conceptual framework of distance education, how the distance education was emerged on the global scene and in India, and then goes on to discuss emergence of online distance education and research aspects in ODE. The initial four chapters provide a detailed account of historical development and growth of distance education in India and State Open University and National Open University Model in India . Student support services are pivot to any distance education and much of its success depends on how well the support services are provided. These are discussed from national and international perspective. The issues of collaborative learning, learning on demand, life long learning, learning-unlearning and re-learning model and strategic alliances have also given due space by the authors. An assortment of technologies like communication technology, domestic technology, information technology, mass media and entertainment technology, media technology and educational technology give an idea of how these technologies are being adopted in the open universities. The study

  14. KNOWLEDGE DISTANCE IN INFORMATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yuhua QIAN; Jiye LIANG; Chuangyin DANG; Feng WANG; Wei XU

    2007-01-01

    In this paper, we first introduce the concepts of knowledge closeness and knowledge distance for measuring the sameness and the difference among knowledge in an information system, respectively.The relationship between these two concepts is a strictly mutual complement relation. We then investigate some important properties of knowledge distance and perform experimental analyses on two public data sets, which show the presented measure appears to be well suited to characterize the nature of knowledge in an information system. Finally, we establish the relationship between the knowledge distance and knowledge granulation, which shows that two variants of the knowledge distance can also be used to construct the knowledge granulation. These results will be helpful for studying uncertainty in information systems.

  15. Are contemporary tourists consuming distance?

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    2012. Background The background for this research, which explores how tourists represent distance and whether or not distance can be said to be consumed by contemporary tourists, is the increasing leisure mobility of people. Travelling for the purpose of visiting friends and relatives is increasing...... of understanding mobility at a conceptual level, and distance matters to people's manifest mobility: how they travel and how far they travel are central elements of their movements. Therefore leisure mobility (indeed all mobility) is the activity of relating across distance, either through actual corporeal...... that is an inherent part of manifest mobility. Numerous definitions and conceptualisations of tourism have been discussed over the years, with MacCannell (1976) pioneering studies of tourism and leisure travel through to Lash and Urry's (1994) post tourist and Jansson's (2002) hyper-tourist. These definitions...

  16. Academy Distance Learning Tools (IRIS)

    Data.gov (United States)

    Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

  17. On error distance of Reed-Solomon codes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The complexity of decoding the standard Reed-Solomon code is a well known open prob-lem in coding theory. The main problem is to compute the error distance of a received word. Using the Weil bound for character sum estimate, we show that the error distance can be determined precisely when the degree of the received word is small. As an application of our method, we give a significant improvement of the recent bound of Cheng-Murray on non-existence of deep holes (words with maximal error distance).

  18. On error distance of Reed-Solomon codes

    Institute of Scientific and Technical Information of China (English)

    LI YuJuan; WAN DaQing

    2008-01-01

    The complexity of decoding the standard Reed-Solomon code is a well known open prob-lem in coding theory.The main problem is to compute the error distance of a received word.Using the Weil bound for character sum estimate,we show that the error distance can be determined precisely when the degree of the received word is small.As an application of our method,we give a significant improvement of the recent bound of Cheng-Murray on non-existence of deep holes (words with maximal error distance).

  19. Distance education: turf and technology.

    Science.gov (United States)

    Pickard, M R

    1992-07-01

    Distance learning fits with the mission and strategic plan of the University of Texas at Arlington. We believe these educational opportunities in nursing are highly desirable. The Board of Nurse Examiners for the State of Texas has approved this project and the Texas Higher Education Coordinating Board has approved it as a pilot project. The school will continue evaluation and creative problem-solving in the use of distance education.

  20. Categorical perception of tactile distance

    OpenAIRE

    Knight, F. L. C.; Longo, M. R.; Bremner, A.J.

    2014-01-01

    The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased ...

  1. Categorical perception of tactile distance.

    Science.gov (United States)

    Knight, Frances Le Cornu; Longo, Matthew R; Bremner, Andrew J

    2014-05-01

    The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased in acuity surrounding anatomical landmarks (in which stimuli near the wrist are perceptually elongated). We tested these two interpretations across two experiments, by comparing a well-documented bias to perceive mediolateral tactile distances across the forearm/hand as larger than proximodistal ones along the forearm/hand at three different sites (hand, wrist, and forearm). According to the 'categorical' interpretation, tactile distances should be elongated selectively in the proximodistal axis thus reducing the anisotropy. According to the 'localised acuity' interpretation, distances will be perceptually elongated in the vicinity of the wrist regardless of orientation, leading to increased overall size without affecting anisotropy. Consistent with the categorical account, we found a reduction in the magnitude of anisotropy at the wrist, with no evidence of a corresponding localised increase in precision. These findings demonstrate that we reference touch to a representation of the body that is categorically segmented into discrete parts, which consequently influences the perception of tactile distance.

  2. Edit Distance to Monotonicity in Sliding Windows

    CERN Document Server

    Chan, Ho-Leung; Lee, Lap-Kei; Pan, Jiangwei; Ting, Hing-Fung; Zhang, Qin

    2011-01-01

    Given a stream of items each associated with a numerical value, its edit distance to monotonicity is the minimum number of items to remove so that the remaining items are non-decreasing with respect to the numerical value. The space complexity of estimating the edit distance to monotonicity of a data stream is becoming well-understood over the past few years. Motivated by applications on network quality monitoring, we extend the study to estimating the edit distance to monotonicity of a sliding window covering the $w$ most recent items in the stream for any $w \\ge 1$. We give a deterministic algorithm which can return an estimate within a factor of $(4+\\eps)$ using $O(\\frac{1}{\\eps^2} \\log^2(\\eps w))$ space. We also extend the study in two directions. First, we consider a stream where each item is associated with a value from a partial ordered set. We give a randomized $(4+\\epsilon)$-approximate algorithm using $O(\\frac{1}{\\epsilon^2} \\log \\epsilon^2 w \\log w)$ space. Second, we consider an out-of-order strea...

  3. Neuronal representations of distance in human auditory cortex.

    Science.gov (United States)

    Kopčo, Norbert; Huang, Samantha; Belliveau, John W; Raij, Tommi; Tengshe, Chinmayi; Ahveninen, Jyrki

    2012-07-03

    Neuronal mechanisms of auditory distance perception are poorly understood, largely because contributions of intensity and distance processing are difficult to differentiate. Typically, the received intensity increases when sound sources approach us. However, we can also distinguish between soft-but-nearby and loud-but-distant sounds, indicating that distance processing can also be based on intensity-independent cues. Here, we combined behavioral experiments, fMRI measurements, and computational analyses to identify the neural representation of distance independent of intensity. In a virtual reverberant environment, we simulated sound sources at varying distances (15-100 cm) along the right-side interaural axis. Our acoustic analysis suggested that, of the individual intensity-independent depth cues available for these stimuli, direct-to-reverberant ratio (D/R) is more reliable and robust than interaural level difference (ILD). However, on the basis of our behavioral results, subjects' discrimination performance was more consistent with complex intensity-independent distance representations, combining both available cues, than with representations on the basis of either D/R or ILD individually. fMRI activations to sounds varying in distance (containing all cues, including intensity), compared with activations to sounds varying in intensity only, were significantly increased in the planum temporale and posterior superior temporal gyrus contralateral to the direction of stimulation. This fMRI result suggests that neurons in posterior nonprimary auditory cortices, in or near the areas processing other auditory spatial features, are sensitive to intensity-independent sound properties relevant for auditory distance perception.

  4. Center—Distance Continuous Probability Models and the Distance Measure

    Institute of Scientific and Technical Information of China (English)

    郑方; 吴文虎; 等

    1998-01-01

    In this paper,a new statistic model named Center-Distance Continuous Probability Model(CDCPM)for speech recognition is described,which is based on Center-Distance Normal(CDN)distribution.In a CDCPM,the probability transition matrix is omitted,and the observation probability density function(PDF)in each state is in the form of embedded multiple-model(EMM)based on the Nearest Neighbour rule.The experimental results on two giant real-world Chinese speech databases and a real-world continuous-manner 2000 phrase system show that this model is a powerful one.Also,a distance measure for CDPMs is proposed which is based on the Bayesian minimum classification error(MCE) discrimination.

  5. Conceptualizing Educational Research in Distance Education.

    Science.gov (United States)

    Watkins, Ryan; Schlosser, Charles

    2003-01-01

    Suggests a starting place for formal inquiry into distance education. Topics covered include: background on educational research and research on distance education; research paradigms that are applicable to distance education; subsystems of a distance education program; and a matrix for conceptualizing distance education research. (MES)

  6. Computing Distances between Probabilistic Automata

    Directory of Open Access Journals (Sweden)

    Mathieu Tracol

    2011-07-01

    Full Text Available We present relaxed notions of simulation and bisimulation on Probabilistic Automata (PA, that allow some error epsilon. When epsilon is zero we retrieve the usual notions of bisimulation and simulation on PAs. We give logical characterisations of these notions by choosing suitable logics which differ from the elementary ones, L with negation and L without negation, by the modal operator. Using flow networks, we show how to compute the relations in PTIME. This allows the definition of an efficiently computable non-discounted distance between the states of a PA. A natural modification of this distance is introduced, to obtain a discounted distance, which weakens the influence of long term transitions. We compare our notions of distance to others previously defined and illustrate our approach on various examples. We also show that our distance is not expansive with respect to process algebra operators. Although L without negation is a suitable logic to characterise epsilon-(bisimulation on deterministic PAs, it is not for general PAs; interestingly, we prove that it does characterise weaker notions, called a priori epsilon-(bisimulation, which we prove to be NP-difficult to decide.

  7. Distance sampling methods and applications

    CERN Document Server

    Buckland, S T; Marques, T A; Oedekoven, C S

    2015-01-01

    In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website.  Some of the case studies use the software Distance, while others use R code. The book is in three parts.  The first part addresses basic methods, the ...

  8. Individual differences in distance perception.

    Science.gov (United States)

    Jackson, Russell E

    2009-05-07

    Distance perception is among the most pervasive mental phenomena and the oldest research topics in behavioural science. However, we do not understand well the most pervasive finding of distance perception research, that of large individual differences. There are large individual differences in acrophobia (fear of heights), which we commonly assume consists of an abnormal fear of stimuli perceived normally. Evolved navigation theory (ENT) instead suggests that acrophobia consists of a more normal fear of stimuli perceived abnormally. ENT suggests that distance perception individual differences produce major components of acrophobia. Acrophobia tested over a broad range in the present study predicted large individual differences in distance estimation of surfaces that could produce falls. This fear of heights correlated positively with distance estimates of a vertical surface-even among non-acrophobic individuals at no risk of falling and without knowledge of being tested for acrophobia. Acrophobia score predicted magnitude of the descent illusion, which is thought to reflect the risk of falling. These data hold important implications in environmental navigation, clinical aetiology and the evolution of visual systems.

  9. Application and research on data mining based on LZ coding prediction algorithm%基于LZ编码预测算法的数据挖掘应用研究

    Institute of Scientific and Technical Information of China (English)

    刘诗淼; 王博

    2016-01-01

    With the rapid development of mobile communication system,the sustainable growth of the user quantity and business category brings new challenges to the system design. For this problem,the application of data mining in user path pre⁃diction technology is studied. The LZ coding prediction scheme is selected to predict the user path of the digital trunking system and simulated. The equipment conditions,application scenarios and user mobile model characteristics of the digital trunking communication system are analyzed to prove its advantages in user path prediction. For the characteristics of the digital trunking communication system,a new dynamic channel reserved algorithm based on path prediction technology is put forward to meet the requirements of system QoS. The proposed scheme is simulated with Matlab,and its performance is compared with that of other schemes. The simulation results show that the new scheme can adjust the system parameters in real⁃time when the business state changes. The call blocking rate of system switching is reduced,and the channel utilization is improved.%随着移动通信系统的快速发展,用户数量和业务种类的持续增长给系统设计带来了新的挑战。针对这种情况,研究了数据挖掘在用户路径预测技术上的应用,选择LZ编码预测方案用于数字集群系统的用户路径预测,并对方案进行了模拟仿真,同时分析了数字集群通信系统设备条件、应用场景和用户移动模型的特点,证明了其在用户路径预测应用上的优势。针对数字集群通信系统的特点,提出一种基于路径预测技术的动态信道预留算法,以满足系统QoS要求。并对提出的方案进行了Matlab仿真研究,与其他方案进行了性能比较,验证了其在业务状态变化下可以通过实时调整系统参数,从而降低系统切换呼叫阻塞率和提高信道利用率。

  10. The Sternum-Nipple Distance is Double the Nipple-Inframammary Fold Distance in Macromastia.

    Science.gov (United States)

    Steele, Thomas N; Pribaz, Julian J; Lau, Frank H

    2017-06-01

    Reduction mammaplasty is one of the most commonly performed plastic surgery operations. For a majority of techniques, the most common long-term complication is pseudoptosis. It has previously been proposed that upper breast suspensory ligaments (SL) are weaker than lower breast SL. We tested this hypothesis through anthropometry of the proxies for upper and lower SL strength: the sternal notch-nipple (SN-N) distance and the nipple-inframammary fold (N-IMF) distance, respectively. An institutional review board-approved retrospective review of patients undergoing reduction mammoplasty in an academic faculty practice between 2008 and 2015 was conducted. Patient demographics included age, race, and body mass index (BMI); patient comorbidities included smoking status, diabetes, and hypertension. Breast anthropometric measurements included SN-N and N-IMF. Sternal notch-nipple was used as the primary metric of the upper SL strength, whereas N-IMF was used as the primary metric of the lower SL strength. Intraoperative details included reduction technique and resection mass. Postoperative complications were recorded, including nipple areola complex necrosis and hematoma. Linear regression analysis was performed with the primary endpoint of the relationship between SN-N and N-IMF distance in macromastia. Data from 208 patients, totaling 400 individual breast measurements, were collected. The mean SN-N length was 35.1 cm, mean N-IMF length was 16.0 cm, and mean resection weight was 1094 g. Linear regression found that N-IMF distance could be predicted as 45% of the SN-N distance (N-IMF = 0.454 * SN-N). This was a strong relationship, demonstrated by univariate analysis of SN-N and N-IMF (R, 0.624; P IMF (R, 0.119; P = 0.017) were both predictive of nipple areola complex necrosis (Table 4). In our series, the N-IMF distance increased 0.45 cm for every 1 cm increase in the SN-N distance. This relationship strengthens our primary hypothesis that the lower pole ligaments stretch

  11. Asymmetric distances for binary embeddings.

    Science.gov (United States)

    Gordo, Albert; Perronnin, Florent; Gong, Yunchao; Lazebnik, Svetlana

    2014-01-01

    In large-scale query-by-example retrieval, embedding image signatures in a binary space offers two benefits: data compression and search efficiency. While most embedding algorithms binarize both query and database signatures, it has been noted that this is not strictly a requirement. Indeed, asymmetric schemes that binarize the database signatures but not the query still enjoy the same two benefits but may provide superior accuracy. In this work, we propose two general asymmetric distances that are applicable to a wide variety of embedding techniques including locality sensitive hashing (LSH), locality sensitive binary codes (LSBC), spectral hashing (SH), PCA embedding (PCAE), PCAE with random rotations (PCAE-RR), and PCAE with iterative quantization (PCAE-ITQ). We experiment on four public benchmarks containing up to 1M images and show that the proposed asymmetric distances consistently lead to large improvements over the symmetric Hamming distance for all binary embedding techniques.

  12. Ghost imaging with broad distance

    Institute of Scientific and Technical Information of China (English)

    段德洋; 张路; 杜少将; 夏云杰

    2015-01-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is.

  13. Euclidean distance geometry an introduction

    CERN Document Server

    Liberti, Leo

    2017-01-01

    This textbook, the first of its kind, presents the fundamentals of distance geometry:  theory, useful methodologies for obtaining solutions, and real world applications. Concise proofs are given and step-by-step algorithms for solving fundamental problems efficiently and precisely are presented in Mathematica®, enabling the reader to experiment with concepts and methods as they are introduced. Descriptive graphics, examples, and problems, accompany the real gems of the text, namely the applications in visualization of graphs, localization of sensor networks, protein conformation from distance data, clock synchronization protocols, robotics, and control of unmanned underwater vehicles, to name several.  Aimed at intermediate undergraduates, beginning graduate students, researchers, and practitioners, the reader with a basic knowledge of linear algebra will gain an understanding of the basic theories of distance geometry and why they work in real life.

  14. Virtual bioinformatics distance learning suite*.

    Science.gov (United States)

    Tolvanen, Martti; Vihinen, Mauno

    2004-05-01

    Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material over the Internet. Currently, we provide two fully computer-based courses, "Introduction to Bioinformatics" and "Bioinformatics in Functional Genomics." Here we will discuss the application of distance learning in bioinformatics training and our experiences gained during the 3 years that we have run the courses, with about 400 students from a number of universities. The courses are available at bioinf.uta.fi.

  15. The Distance Geometry of Music

    CERN Document Server

    Demaine, Erik D; Meijer, Henk; Rappaport, David; Taslakian, Perouz; Toussaint, Godfried T; Winograd, Terry; Wood, David R

    2007-01-01

    We demonstrate relationships between the classic Euclidean algorithm and many other fields of study, particularly in the context of music and distance geometry. Specifically, we show how the structure of the Euclidean algorithm defines a family of rhythms which encompass over forty timelines (\\emph{ostinatos}) from traditional world music. We prove that these \\emph{Euclidean rhythms} have the mathematical property that their onset patterns are distributed as evenly as possible: they maximize the sum of the Euclidean distances between all pairs of onsets, viewing onsets as points on a circle. Indeed, Euclidean rhythms are the unique rhythms that maximize this notion of \\emph{evenness}. We also show that essentially all Euclidean rhythms are \\emph{deep}: each distinct distance between onsets occurs with a unique multiplicity, and these multiplicies form an interval $1,2,...,k-1$. Finally, we characterize all deep rhythms, showing that they form a subclass of generated rhythms, which in turn proves a useful prop...

  16. Adaptive Distance Protection for Microgrids

    DEFF Research Database (Denmark)

    Lin, Hengwei; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2015-01-01

    Due to the increasing penetration of distributed generation resources, more and more microgrids can be found in distribution systems. This paper proposes a phasor measurement unit based distance protection strategy for microgrids in distribution system. At the same time, transfer tripping scheme...... is adopted to accelerate the tripping speed of the relays on the weak lines. The protection methodology is tested on a mid-voltage microgrid network in Aalborg, Denmark. The results show that the adaptive distance protection methodology has good selectivity and sensitivity. What is more, this system also has...

  17. Fast Exact Euclidean Distance (FEED) Transformation

    NARCIS (Netherlands)

    Schouten, Theo; Broek, van den Egon; Kittler, J.; Petrou, M.; Nixon, M.

    2004-01-01

    Fast Exact Euclidean Distance (FEED) transformation is introduced, starting from the inverse of the distance transformation. The prohibitive computational cost of a naive implementation of traditional Euclidean Distance Transformation, is tackled by three operations: restriction of both the number o

  18. Effect of Image Linearization on Normalized Compression Distance

    Science.gov (United States)

    Mortensen, Jonathan; Wu, Jia Jie; Furst, Jacob; Rogers, John; Raicu, Daniela

    Normalized Information Distance, based on Kolmogorov complexity, is an emerging metric for image similarity. It is approximated by the Normalized Compression Distance (NCD) which generates the relative distance between two strings by using standard compression algorithms to compare linear strings of information. This relative distance quantifies the degree of similarity between the two objects. NCD has been shown to measure similarity effectively on information which is already a string: genomic string comparisons have created accurate phylogeny trees and NCD has also been used to classify music. Currently, to find a similarity measure using NCD for images, the images must first be linearized into a string, and then compared. To understand how linearization of a 2D image affects the similarity measure, we perform four types of linearization on a subset of the Corel image database and compare each for a variety of image transformations. Our experiment shows that different linearization techniques produce statistically significant differences in NCD for identical spatial transformations.

  19. The Future of Distance Education.

    Science.gov (United States)

    Saba, Farhad

    2000-01-01

    Examines factors that will influence how distance education is practiced in the first few decades of this new century. Discusses developments in digital technology; the exponential growth of knowledge about the brain, as well as physiology, chemistry, and psychology of learning; the system relationship between individual learners and instructors;…

  20. Using Podcasts in Distance Education

    Science.gov (United States)

    Koppelman, Herman

    2013-01-01

    This paper discusses three possible ways of applying podcasts in distance education: podcasts of recordings of virtual classes, podcasts produced for specific pedagogical aims, and podcasts produced by external organizations. Through a survey we gained insight in the (until now limited) experiences of our distant students with podcasts, and also…

  1. Distance Education Instructional Model Applications.

    Science.gov (United States)

    Jackman, Diane H.; Swan, Michael K.

    1995-01-01

    A survey of graduate students involved in distance education on North Dakota State University's Interactive Video Network included 80 on campus and 13 off. The instructional models rated most effective were role playing, simulation, jurisprudential (Socratic method), memorization, synectics, and inquiry. Direct instruction was rated least…

  2. Distance, Lending Relationships, and Competition

    NARCIS (Netherlands)

    Degryse, H.A.; Ongena, S.

    2003-01-01

    A recent string of theoretical papers has highlighted the importance of geographical distance in explaining loan rates for small firms.Lenders located in the vicinity of small firms face significantly lower transportation and monitoring costs, and hence wield considerable market power, if competing

  3. Favourite distances in high dimensions

    CERN Document Server

    Swanepoel, Konrad J

    2011-01-01

    Let $S$ be a set of $n$ points in $d$-dimensional Euclidean space. Assign to each $x\\in S$ an arbitrary distance $r(x)>0$. Let $e_r(x,S)$ denote the number of points in $S$ at distance $r(x)$ from $x$. Avis, Erd\\"os and Pach (1988) introduced the extremal quantity $f_d(n)=\\max\\sum_{x\\in S}e_r(x,S)$, where the maximum is taken over all $n$-point sets $S$ in $d$-dimensional space and all assignments $r\\colon S\\to(0,\\infty)$ of distances. We give a quick derivation of the asymptotics of the error term of $f_d(n)$ using only the analogous asymptotics of the maximum number of unit distance pairs in a set of $n$ points, which improves on previous results of Avis, Erd\\"os and Pach (1988) and Erd\\"os and Pach (1990). Then we prove a stability result for $d\\geq 4$, asserting that if $(S,r)$ with $|S|=n$ satisfies $e_r(S)=f_d(n)-o(n^2)$, then, up to $o(n)$ points, $S$ is a Lenz construction with $r$ constant. Finally we use stability to show that for $n$ sufficiently large (depending on $d$) the pairs $(S,r)$ that atta...

  4. Lessons in Developing Distance Learning.

    Science.gov (United States)

    Gant, Lenora Peters

    1996-01-01

    Describes the use of video teletraining (VTT) for distance learning in the Department of Defense. Topics include planning and organizing the VTT facility, staff development, site facilitators, the necessity of protocol, instructional design and development strategies, student involvement and interactivity, and evaluation and assessment. (LRW)

  5. Communication Barriers in Distance Education

    Science.gov (United States)

    Isman, Aytekin; Dabaj, Fahme; Altinay, Fahriye; Altinay, Zehra

    2003-01-01

    Communication is a key concept as being the major tool for people in order to satisfy their needs. It is an activity which refers as process and effective communication requires qualified communication with the elimination of communication barriers. As it is known, distance education is a new trend by following contemporary facilities and tools…

  6. Distance Learning: Untried and Untrue

    Science.gov (United States)

    Halfond, Jay A.

    2010-01-01

    G. K. Chesterton famously once said: "Christianity has not been tried and found wanting; it has been found difficult and not tried." This, the author believes, applies to distance learning as well. There is far too much self-congratulatory hyperbole about the growth and pervasiveness of online learning--which exaggerates reality and overlooks the…

  7. Curriculum Control in Distance Education.

    Science.gov (United States)

    Chesterton, Paul

    1985-01-01

    The nature of distance education is to shift the locus of curriculum control toward the institution and its staff and away from the students. This imposes a responsibility on the institution to examine and evaluate the values and assumptions underlying the decision-making and the implications of the patterns of control that emerge. (Author/MSE)

  8. Distance, Lending Relationships and Competition

    NARCIS (Netherlands)

    Degryse, H.A.; Ongena, S.

    2002-01-01

    A recent string of theoretical papers highlights the importance of geographical distance in explaining pricing and availability of loans to small firms.Lenders located in the vicinity of small firms have significantly lower monitoring and transaction costs, and hence considerable market power if com

  9. On Maximum Lee Distance Codes

    OpenAIRE

    Alderson, Tim L.; Svenja Huntemann

    2013-01-01

    Singleton-type upper bounds on the minimum Lee distance of general (not necessarily linear) Lee codes over ℤq are discussed. Two bounds known for linear codes are shown to also hold in the general case, and several new bounds are established. Codes meeting these bounds are investigated and in some cases characterised.

  10. Video Surveillance using Distance Maps

    NARCIS (Netherlands)

    Schouten, Theo E.; Kuppens, Harco C.; Broek, van den Egon L.; Kehtarnavaz, Nasser; Laplante, Phillip A.

    2006-01-01

    Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors.

  11. Gesture Interaction at a Distance

    NARCIS (Netherlands)

    Fikkert, F.W.

    2010-01-01

    The aim of this work is to explore, from a perspective of human behavior, which gestures are suited to control large display surfaces from a short distance away; why that is so; and, equally important, how such an interface can be made a reality. A well-known example of the type of interface that is

  12. The Perception of Ideological Distance

    NARCIS (Netherlands)

    Granberg, Donald; Brown, Thad A.

    1992-01-01

    Data from national election studies in Britain, the Netherlands, Sweden, and the U.S. were analyzed to test hypotheses concerning the perception of ideological distance between parties and candidates. The first hypothesis, derived from Sherif's social judgment theory and Heider's balance theory, was

  13. Isolation by distance, web service

    Directory of Open Access Journals (Sweden)

    Bohonak Andrew J

    2005-03-01

    Full Text Available Abstract Background The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. Results We have created Isolation by Distance Web Service (IBDWS a user-friendly web interface for determining patterns of isolation by distance. Using this site, population geneticists can perform a variety of powerful statistical tests including Mantel tests, Reduced Major Axis (RMA regression analysis, as well as calculate FST between all pairs of populations and perform basic summary statistics (e.g., heterozygosity. All statistical results, including publication-quality scatter plots in Postscript format, are returned rapidly to the user and can be easily downloaded. Conclusion IBDWS population genetics analysis software is hosted at http://phage.sdsu.edu/~jensen/ and documentation is available at http://www.bio.sdsu.edu/pub/andy/IBD.html. The source code has been made available on Source Forge at http://sourceforge.net/projects/ibdws/.

  14. Video surveillance using distance maps

    NARCIS (Netherlands)

    Schouten, Theo E.; Kuppens, Harco C.; van den Broek, Egon; Kehtarnavaz, Nasser; Laplante, Phillip A,

    2006-01-01

    Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors.

  15. Making Distance Visible: Assembling Nearness in an Online Distance Learning Programme

    Directory of Open Access Journals (Sweden)

    Jen Ross

    2013-09-01

    Full Text Available Online distance learners are in a particularly complex relationship with the educational institutions they belong to (Bayne, Gallagher, & Lamb, 2012. For part-time distance students, arrivals and departures can be multiple and invisible as students take courses, take breaks, move into independent study phases of a programme, find work or family commitments overtaking their study time, experience personal upheaval or loss, and find alignments between their professional and academic work. These comings and goings indicate a fluid and temporary assemblage of engagement, not a permanent or stable state of either “presence” or “distance”. This paper draws from interview data from the “New Geographies of Learning” project, a research project exploring the notions of space and institution for the MSc in Digital Education at the University of Edinburgh, and from literature on distance learning and online community. The concept of nearness emerged from the data analyzing the comings and goings of students on a fully online programme. It proposes that “nearness” to a distance programme is a temporary assemblage of people, circumstances, and technologies. This state is difficult to establish and impossible to sustain in an uninterrupted way over the long period of time that many are engaged in part-time study. Interruptions and subsequent returns should therefore be seen as normal in the practice of studying as an online distance learner, and teachers and institutions should work to help students develop resilience in negotiating various states of nearness. Four strategies for increasing this resilience are proposed: recognising nearness as effortful; identifying affinities; valuing perspective shifts; and designing openings.

  16. A Streaming Distance Transform Algorithm for Neighborhood-Sequence Distances

    Directory of Open Access Journals (Sweden)

    Nicolas Normand

    2014-09-01

    Full Text Available We describe an algorithm that computes a “translated” 2D Neighborhood-Sequence Distance Transform (DT using a look up table approach. It requires a single raster scan of the input image and produces one line of output for every line of input. The neighborhood sequence is specified either by providing one period of some integer periodic sequence or by providing the rate of appearance of neighborhoods. The full algorithm optionally derives the regular (centered DT from the “translated” DT, providing the result image on-the-fly, with a minimal delay, before the input image is fully processed. Its efficiency can benefit all applications that use neighborhood- sequence distances, particularly when pipelined processing architectures are involved, or when the size of objects in the source image is limited.

  17. Effective Teaching in Distance Education. ERIC Digest.

    Science.gov (United States)

    Mielke, Dan

    Distance education is an alternative method for delivering academic course work to students unable to attend traditional campus-based classes. This Digest presents information on the many forms of distance education and keys to successful teaching with distance education. Distance education is a method of education in which the learner is…

  18. The intractability of computing the Hamming distance

    NARCIS (Netherlands)

    Manthey, Bodo; Reischuk, Rüdiger

    2005-01-01

    Given a string x and a language L, the Hamming distance of x to L is the minimum Hamming distance of x to any string in L. The edit distance of a string to a language is analogously defined. First, we prove that there is a language in $AC^0$ such that both Hamming and edit distance to this language

  19. Distance Education Use in Rural Schools

    Science.gov (United States)

    Hannum, Wallace H.; Irvin, Matthew J.; Banks, Jonathan B.; Farmer, Thomas W.

    2009-01-01

    A national survey of rural school systems in the United States was conducted to determine the extent to which distance education is being utilized by rural schools, the technologies used, the curriculum areas impacted, the perceived needs for distance education, their satisfaction with distance education, and the barriers to distance education…

  20. History and Heritage in Distance Education

    Science.gov (United States)

    Anderson, Bill; Simpson, Mary

    2012-01-01

    Distance education's history is a tremendous resource for all involved in distance education. Some aspects of that history provide enduring touchstones for present distance educators, creating a heritage that should not be overlooked as distance education continues to develop and expand. In this article we draw on the concept of generational…

  1. Determining distances using asteroseismic methods

    CERN Document Server

    Aguirre, V Silva; Basu, S; Campante, T L; Chaplin, W J; Huber, D; Miglio, A; Serenelli, A M; WG#1, KASC

    2012-01-01

    Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the results is needed. In this talk, I present a new technique developed to obtain stellar properties by coupling asteroseismic analysis with the InfraRed Flux Method. Using two global seismic observables and multi-band photometry, the technique determines masses, radii, effective temperatures, bolometric fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\\it Kepler} field that have accurate {\\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements of spectroscopic effective temperatures and interferometric radii also validate our results, and show that our technique can ...

  2. Managerial Distance and Virtual Ownership

    DEFF Research Database (Denmark)

    Hansmann, Henry; Thomsen, Steen

    Industrial foundations are autonomous nonprofit entities that own and control one or more conventional business firms. These foundations are common in Northern Europe, where they own a number of internationally prominent companies. Previous studies have indicated, surprisingly, that companies con......, but corporate governance and fiduciary behavior more generally....... on differences among the industrial foundations themselves. We work with a rich data set comprising 113 foundation-owned Danish companies over the period 2003-2008. We focus in particular on a composite structural factor that we term “managerial distance.” We propose this as a measure of the extent to which......-seeking outside owners of the company. Consistent with this hypothesis, our empirical analysis shows a positive, significant, and robust association between managerial distance and the economic performance of foundation owned companies. The findings appear to illuminate not just foundation governance...

  3. Theological Librarianship from a Distance

    Directory of Open Access Journals (Sweden)

    Melody Diehl Detar

    2015-08-01

    Full Text Available This essay examines distance theological librarianship and the field’s suitability for remote librarians. A brief introduction to the landscape of online programs in theological education is followed by an overview of virtual librarianship and how theological librarians may serve students while working from a distance themselves. The essay then describes a method for initiating a remote librarian position in a theological library context, and then reviews the steps of determining whether remote work is feasible and desirable at an institution, approaching leadership with a plan, setting up a trial remote work period, and assessing its success. Particular emphasis is given to communication expectations, modes of virtual reference and instruction, campus committee service and meaningful ways of remaining part of the campus community.

  4. Moral distance in dictator games

    Directory of Open Access Journals (Sweden)

    Fernando Aguiar

    2008-04-01

    Full Text Available We perform an experimental investigation using a dictator game in which individuals must make a moral decision --- to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory. %extit{JEL}: A13, C72, C91

  5. Students’ Role in Distance Learning

    OpenAIRE

    Beers Fägersten, Kristy

    2008-01-01

    1. IntroductionMuch of the support that students have in a traditional classroom is absent in a distance learning course. In the traditional classroom, the learner is together with his or her classmates and the teacher; learning is socially embedded. Students can talk to each other and may learn from each other as they go through the learning process together. They also witness the teacher’s expression of the knowledge firsthand. The class participants communicate to each other not ...

  6. Distance probes of dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D’Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; Eisenstein, D. J.; Finley, D. A.; Freedman, W. L.; Ho, S.; Holz, D. E.; Kasen, D.; Kent, S. M.; Kessler, R.; Kuhlmann, S.; Linder, E. V.; Martini, P.; Nugent, P. E.; Perlmutter, S.; Peterson, B. M.; Riess, A. G.; Rubin, D.; Sako, M.; Suntzeff, N. V.; Suzuki, N.; Thomas, R. C.; Wood-Vasey, W. M.; Woosley, S. E.

    2015-03-01

    This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  7. Hardware Euclidean Distance Transform Implementation

    Institute of Scientific and Technical Information of China (English)

    XIE Ying-hua; ZENG Pei-feng; TANG Li-ping

    2004-01-01

    Based on an efficient algorithm of Euclidean distance transform for binary images, a circuit of O(N2) size is proposed. With in-place calculation, both the intermediate data storing and the result output use the same memory with the input data. This reduces the amount of memory largely. By replacing multipliers with counters, comparators, and adders, the circuit size is further reduced and its calculation speed is improved also.

  8. Distance Probes of Dark Energy

    CERN Document Server

    Kim, A; Aldering, G; Allen, S; Baltay, C; Cahn, R; D'Andrea, C; Dalal, N; Dawson, K; Denney, K; Eisenstein, D; Finley, D; Freedman, W; Ho, S; Holz, D; Kent, A; Kasen, D; Kessler, R; Kuhlmann, S; Linder, E; Martini, P; Nugent, P; Perlmutter, S; Peterson, B; Riess, A; Rubin, D; Sako, M; Suntzeff, N; Suzuki, N; Thomas, R; Wood-Vasey, W M; Woosley, S

    2013-01-01

    This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type IA supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  9. Distance effects in electrochemical micromachining

    OpenAIRE

    2016-01-01

    Considering exponential dependence of currents on double-layer voltage and the feedback effect of the electrolyte resistance, a distance effect in electrochemical micromachining is found, namely that both time constant and double-layer voltage depend on the separation of electrodes. The double-layer voltage is the real voltage used in processing. Under DC voltage, the apparent voltages between two electrodes are constant for different separations, but the real voltages change with the separat...

  10. The Magnetotail at Lunar Distance

    Science.gov (United States)

    Sibeck, D. G.

    2015-12-01

    This presentation reviews some of the single-point observations of the magnetotail at lunar distances made by ALSEP, Explorer 33, 35, ISEE-3, and Geotail that form the framework for interpreting more recent dual-spacecraft ARTEMIS observations. Earth's distant magnetotail flaps, twists, and flattens in response to variations in the solar wind flow direction and interplanetary magnetic field (IMF) orientation. It may even disappear leaving nothing more than a wake during strongly northward IMF orientations. Standing slow mode expansion fans provide for a gradual transition between magnetotail lobe and magnetosheath plasma and magnetic field parameters. The distant neutral line may at times reside at lunar distances, creating jets of sunward-streaming plasma within the cislunar plasma sheet and layers of streaming energetic particles on its boundaries. Reconnection at near-Earth neutral lines releases antisunward-moving plasmoids that transit lunar distances, briefly expanding the diameter of the plasma sheet and magnetotail. Taken as a whole, the distant magnetotail is a fascinating plasma laboratory and a region of great important to the magnetosphere.

  11. Support Services for Distance Education

    Directory of Open Access Journals (Sweden)

    Sandra Frieden

    1999-01-01

    Full Text Available The creation and operation of a distance education support infrastructure requires the collaboration of virtually all administrative departments whose activities deal with students and faculty, and all participating academic departments. Implementation can build on where the institution is and design service-oriented strategies that strengthen institutional support and commitment. Issues to address include planning, faculty issues and concerns, policies and guidelines, approval processes, scheduling, training, publicity, information-line operations, informational materials, orientation and registration processes, class coordination and support, testing, evaluations, receive site management, partnerships, budgets, staffing, library and e-mail support, and different delivery modes (microwave, compressed video, radio, satellite, public television/cable, video tape and online. The process is ongoing and increasingly participative as various groups on campus begin to get involved with distance education activities. The distance education unit must continuously examine and revise its processes and procedures to maintain the academic integrity and service excellence of its programs. It’s a daunting prospect to revise the way things have been done for many years, but each department has an opportunity to respond to new ways of serving and reaching students.

  12. Social distance evaluation in human parietal cortex.

    Science.gov (United States)

    Yamakawa, Yoshinori; Kanai, Ryota; Matsumura, Michikazu; Naito, Eiichi

    2009-01-01

    Across cultures, social relationships are often thought of, described, and acted out in terms of physical space (e.g. "close friends" "high lord"). Does this cognitive mapping of social concepts arise from shared brain resources for processing social and physical relationships? Using fMRI, we found that the tasks of evaluating social compatibility and of evaluating physical distances engage a common brain substrate in the parietal cortex. The present study shows the possibility of an analytic brain mechanism to process and represent complex networks of social relationships. Given parietal cortex's known role in constructing egocentric maps of physical space, our present findings may help to explain the linguistic, psychological and behavioural links between social and physical space.

  13. NEW HAUSDORFF DISTANCE-BASED VEHICLE LOCATION

    Institute of Scientific and Technical Information of China (English)

    陈莹; 韩崇昭

    2004-01-01

    Objective To realize accurate localization of moving vehicles from single monocular intensity image. Methods The new modified Hausdorff distance(M2HD) was adopted, which used dominant points instead of edge maps as features for measuring similarity between image and model projection. Modified simulated annealing (MSA) algorithm was used to find optimum localization parameters. Results M2HD reduces the computational complexity, and improves the matching precision. Furthermore, MSA can fast find global optimum instead of getting into partial one because of its high parallel and robust performance. Conclusion Experiments confirm that the combination of MSA and M2HD can effectively localize the vehicles that are changed both in translation and rotation

  14. Social distancing strategies against disease spreading

    CERN Document Server

    Valdez, L D; Macri, P A; Braunstein, L A

    2013-01-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, $i.e$, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibil...

  15. Focus characteristics of long distance flying optics

    Institute of Scientific and Technical Information of China (English)

    程兆谷; 蒋金波; 李现勤; 许国良; 夏金安; W.M.Steen; G.Dearden

    2000-01-01

    The ABCD law for the complex parameter q of the TEM00 Gaussian beam is generally not valid for high-order modes. It can be used for the high-order modes or their superposition when the spot size w in the virtual part of the parameter q is substituted by the Rayleigh range ZR of a certain resonator. The focus characteristics of long distance flying optics are studied in this paper theoretically and experimentally for the TEMmn Gaussian beams between the two types of resonators without and with distortion. It is very important for the applications of the flying optical processing, the laser space craft and the spatial filter in the large laser project.

  16. Editorial ~ Global Diversity of Distance Education

    OpenAIRE

    2001-01-01

    In a panel presentation at the recent International Council for Open and Distance Education (ICDE) world conference in Dusseldorf, Germany, I had the opportunity to explain the unique role and mission of International Review of Research in Open and Distance Learning (IRRODL) vis – vis our more established sister journals: Open Praxis, Open Learning, Journal of Distance Education, Distance Education, and American Journal of Distance Education. Although all of these journals share a common comm...

  17. The Monge distance between quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Zyczkowski, Karol [Institute for Plasma Research, University of Maryland, College Park, MD (United States); Slomczynski, Wojciech [Instytut Matematyki, Uniwersytet Jagiellonski, Cracow (Poland)

    1998-11-13

    We define a metric in the space of quantum states taking the Monge distance between corresponding Husimi distributions (Q-functions). This quantity fulfils the axioms of a metric and satisfies the following semiclassical property: the distance between two coherent states is equal to the Euclidean distance between corresponding points in the classical phase space. We compute analytically distances between certain states (coherent, squeezed, Fock and thermal) and discuss a scheme for numerical computation of Monge distance for two arbitrary quantum states. (author)

  18. 新形势下提高自考生职业竞争力的探讨——以LZ学校为例%The Study Of Improve Career Competitiveness of Self-Taught Student Under The New Situation ——Taking The LZ School As An Example

    Institute of Scientific and Technical Information of China (English)

    王萍

    2012-01-01

    In recent years, higher education self-study exam system which leading to our country's higher education full-time self-study exam management highlights a series of problems. This paper based on the analysis of the current situation of LZ school and taking an examination of itself to study and improving employment competition ability from new measures.%在近年国内普通高校扩招,高等教育自学考试制度改革形势下,高等教育全日制自学考试管理凸显了一系列问题。本文通过对LZ学校自考现状的分析,探讨了提高自考生就业竞争能力新举措。

  19. Complexity reduction for C4 compression for implementation in maskless lithography datapath

    Science.gov (United States)

    Dai, Vito; Zakhor, Avideh

    2005-05-01

    Achieving the throughput of one wafer per minute per layer with a direct-write maskless lithography system, using 25 nm pixels for 50 nm feature sizes, requires data rates of about 10 Tb/s. In previous work, we have shown that lossless binary compression plays a key role in the system architecture for such a maskless writing system. Recently, we developed a new compression technique Context-Copy-Combinatorial-Code (C4) specifically tailored to lithography data which exceeds the compression efficiency of all other existing techniques including BZIP2, 2D-LZ, and LZ77. The decoder for any chosen compression scheme must be replicated in hardware tens of thousands of times in any practical direct write lithography system utilizing compression. As such, decode implementation complexity has a significant impact on overall complexity. In this paper, we explore the tradeoff between the compression ratio, and decoder buffer size for C4. Specifically, we present a number of techniques to reduce the complexity for C4 compression. First, buffer compression is introduced as a method to reduce decoder buffer size by an order of magnitude without sacrificing compression efficiency. Second, linear prediction is used as a low-complexity alternative to both context-based prediction and binarization. Finally, we allow for copy errors, which improve the compression efficiency of C4 at small buffer sizes. With these techniques in place, for a fixed buffer size, C4 achieves a significantly higher compression ratio than those of existing compression algorithms. We also present a detailed functional block diagram of the C4 decoding algorithm as a first step towards a hardware realization.

  20. Robust Estimation of Evolutionary Distances with Information Theory.

    Science.gov (United States)

    Cao, Minh Duc; Allison, Lloyd; Dix, Trevor I; Bodén, Mikael

    2016-05-01

    Methods for measuring genetic distances in phylogenetics are known to be sensitive to the evolutionary model assumed. However, there is a lack of established methodology to accommodate the trade-off between incorporating sufficient biological reality and avoiding model overfitting. In addition, as traditional methods measure distances based on the observed number of substitutions, their tend to underestimate distances between diverged sequences due to backward and parallel substitutions. Various techniques were proposed to correct this, but they lack the robustness against sequences that are distantly related and of unequal base frequencies. In this article, we present a novel genetic distance estimate based on information theory that overcomes the above two hurdles. Instead of examining the observed number of substitutions, this method estimates genetic distances using Shannon's mutual information. This naturally provides an effective framework for balancing model complexity and goodness of fit. Our distance estimate is shown to be approximately linear to elapsed time and hence is less sensitive to the divergence of sequence data and compositional biased sequences. Using extensive simulation data, we show that our method 1) consistently reconstructs more accurate phylogeny topologies than existing methods, 2) is robust in extreme conditions such as diverged phylogenies, unequal base frequencies data, and heterogeneous mutation patterns, and 3) scales well with large phylogenies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Mattig's relation and dynamical distance indicators

    CERN Document Server

    Teerikorpi, Pekka

    2016-01-01

    We discuss how the redshift (Mattig) method in Friedmann cosmology relates to dynamical distance indicators based on Newton's gravity (Teerikorpi 2011). It belongs to the class of indicators where the relevant length inside the system is the distance itself (in this case the proper metric distance). As the Friedmann model has Newtonian analogy, its use to infer distances has instructive similarities to classical dynamical distance indicators. In view of the theoretical exact linear distance-velocity law, we emphasize that it is conceptually correct to derive the cosmological distance via the route: redshift (primarily observed) --> space expansion velocity (not directly observed) --> metric distance (physical length in "cm"). Important properties of the proper metric distance are summarized.

  2. An overview on distance and pseudo distance functions and their applications

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiangyang; DING Han; ZHONG Binglin; XIONG Youlun

    2003-01-01

    The fast and accurate collision detection and distance calculation between geometric models is fundamental in robotics, manufacturing and computer-simulated environments. This paper surveys the state of the art in the theory and algorithms of distance and pseudo distance functions between convex sets. An overview on the existing results, including fast algorithms for distance calculation, definitions and properties of various pseudo distance functions (the J-function, the growth distance, and the pseudo minimum translational distance), is presented. The distance and pseudo distance functions are versatile in a wide range of areas. Their applications in robot motion planning, grasp analysis/synthesis, form error evaluation, and engineering optimization is demonstrated.

  3. Distance Measurement Solves Astrophysical Mysteries

    Science.gov (United States)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

  4. Variable Distance Angular Symbology Reader

    Science.gov (United States)

    Schramm, Harry F., Jr. (Inventor); Corder, Eric L. (Inventor)

    2006-01-01

    A variable distance angular symbology, reader utilizes at least one light source to direct light through a beam splitter and onto a target. A target may be angled relative to the impinging light beam up to and maybe even greater than 45deg. A reflected beam from the target passes through the beam splitter and is preferably directed 90deg relative to the light source through a telecentric lens to a scanner which records an image of the target such as a direct part marking code.

  5. Anxiety and Resistance in Distance Learning

    Directory of Open Access Journals (Sweden)

    Nazime Tuncay

    2010-06-01

    Full Text Available The purpose of this study was to investigate students' anxiety and resistance towards learning through distance education.Specifically, the study sought answers to the following questions: -What are the reasons of students not choosing distancelearning courses? -Which symptoms of anxiety, if any, do distance learner’s exhibit towards distance learning? Does genderhave any significant relationships with distance learners' perception of factors that affect their anxiety and resistance? A totalof 120 distance education students in Near East University were observed and 96 of them were interviewed. Computer anxiety,language anxiety, social anxiety were observed to be among the reasons of students’ resistance to distance learning.

  6. A note on the path interval distance.

    Science.gov (United States)

    Coons, Jane Ivy; Rusinko, Joseph

    2016-06-01

    The path interval distance accounts for global congruence between locally incongruent trees. We show that the path interval distance provides a lower bound for the nearest neighbor interchange distance. In contrast to the Robinson-Foulds distance, random pairs of trees are unlikely to be maximally distant from one another under the path interval distance. These features indicate that the path interval distance should play a role in phylogenomics where the comparison of trees on a fixed set of taxa is becoming increasingly important.

  7. Lightweight Distance Bounding Protocol against Relay Attacks

    Science.gov (United States)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  8. Three-Distance Sequences with Three Symbols

    OpenAIRE

    SAKAMOTO, Kuniko

    2003-01-01

    We will show that every $3$ dimensional cutting sequence is a three-distance sequence, and there are uncountable many periodic or aperiodic three-distance sequences (with $3$-symbols) which are not $3$ dimensional cutting sequences.

  9. A Cognitively Grounded Measure of Pronunciation Distance

    NARCIS (Netherlands)

    Wieling, M.; Nerbonne, J.; Bloem, J.; Gooskens, C.; Heeringa, W.; Baayen, R.H.

    2014-01-01

    In this study we develop pronunciation distances based on naive discriminative learning (NDL). Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is groun

  10. The Euclidean Algorithm for Generalized Minimum Distance Decoding of Reed-Solomon Codes

    CERN Document Server

    Kampf, Sabine

    2010-01-01

    This paper presents a method to merge Generalized Minimum Distance decoding of Reed-Solomon codes with the extended Euclidean algorithm. By merge, we mean that the steps taken to perform the Generalized Minimum Distance decoding are similar to those performed by the extended Euclidean algorithm. The resulting algorithm has a complexity of O(n^2).

  11. THE INFLUENCE OF WOMEN ON DISTANCE EDUCATION

    OpenAIRE

    2014-01-01

    The impact of distance education on women has been significant. Distance education has been a viable means for helping women reach their educational ambitions. Over the last 40 years distance education has increased the ease of access and control over study time. With geographical and time barriers removed, women in particular were able to add the role of student to their list of responsibilities. Women have defeated educational barriers through educational opportunities presented by distance...

  12. Distance-based classification of keystroke dynamics

    Science.gov (United States)

    Tran Nguyen, Ngoc

    2016-07-01

    This paper uses the keystroke dynamics in user authentication. The relationship between the distance metrics and the data template, for the first time, was analyzed and new distance based algorithm for keystroke dynamics classification was proposed. The results of the experiments on the CMU keystroke dynamics benchmark dataset1 were evaluated with an equal error rate of 0.0614. The classifiers using the proposed distance metric outperform existing top performing keystroke dynamics classifiers which use traditional distance metrics.

  13. Complex networks analysis of language complexity

    CERN Document Server

    Amancio, Diego R; Oliveira, Osvaldo N; Costa, Luciano da F; 10.1209/0295-5075/100/58002

    2013-01-01

    Methods from statistical physics, such as those involving complex networks, have been increasingly used in quantitative analysis of linguistic phenomena. In this paper, we represented pieces of text with different levels of simplification in co-occurrence networks and found that topological regularity correlated negatively with textual complexity. Furthermore, in less complex texts the distance between concepts, represented as nodes, tended to decrease. The complex networks metrics were treated with multivariate pattern recognition techniques, which allowed us to distinguish between original texts and their simplified versions. For each original text, two simplified versions were generated manually with increasing number of simplification operations. As expected, distinction was easier for the strongly simplified versions, where the most relevant metrics were node strength, shortest paths and diversity. Also, the discrimination of complex texts was improved with higher hierarchical network metrics, thus point...

  14. Distance learning for training business game tutors

    Directory of Open Access Journals (Sweden)

    Mariana de Toledo Marinho

    Full Text Available Abstract This work is the result of research that proposes the incorporation of Distance Learning into a Business Game as a strategy to enhance tutor training, considering entrepreneurship difficulties faced by public school teachers. Part of the problem could be attributed to subject type, because, in general, it is not common to find entrepreneurship on school curricula. The Distance Learning (DL activities were developed using the Moodle platform and structured by topic to increase educational flexibility and achieve a better balance between individual reflection and online discussion. It was developed in four steps: course content development; course evaluation by computer technicians; restructuring the course based on course evaluation done by computer technicians and course evaluation by teachers from the public school system. A preliminary test was performed with informatics technicians to technically evaluate the learning environment. Based on this, the course was restructured, applying corrections and adjustments to improve environment usability. After corrections, a final test was conducted with public school system teachers to analyze user perception, which gave a positive result. Virtual learning environment evaluation is complex and multidisciplinary, requiring the technical knowledge of internet programming and a conceptual knowledge of education, especially in the field of learning. When the evaluation done by teachers was examined, it was found that deficiencies pointed out by computer technicians had been resolved, giving a positive rating. This current research concludes that DL can improve the use of games, because it is possible to structure the content related to the learning gaps of specific groups of students. In this respect the use of games results can guide the development of content.

  15. Distance effects in electrochemical micromachining

    Science.gov (United States)

    Xu, Lizhong; Pan, Yue; Zhao, Chuanjun

    2016-09-01

    Considering exponential dependence of currents on double-layer voltage and the feedback effect of the electrolyte resistance, a distance effect in electrochemical micromachining is found, namely that both time constant and double-layer voltage depend on the separation of electrodes. The double-layer voltage is the real voltage used in processing. Under DC voltage, the apparent voltages between two electrodes are constant for different separations, but the real voltages change with the separations. Small separations exert substantial effects on the real voltages. Accordingly, a DC-voltage small-separation electrochemical micromachining technique was proposed. The double-layer voltage drops sharply as the small separation increases. Thus, the electrochemical reactions are confined to electrode regions in very close proximity even under DC voltage. The machining precision can be significantly enhanced by reducing the voltage and separation between electrodes. With this technique, the machining of conducting materials with submicrometre precision was achieved.

  16. Time delay and distance measurement

    Science.gov (United States)

    Abshire, James B. (Inventor); Sun, Xiaoli (Inventor)

    2011-01-01

    A method for measuring time delay and distance may include providing an electromagnetic radiation carrier frequency and modulating one or more of amplitude, phase, frequency, polarization, and pointing angle of the carrier frequency with a return to zero (RZ) pseudo random noise (PN) code. The RZ PN code may have a constant bit period and a pulse duration that is less than the bit period. A receiver may detect the electromagnetic radiation and calculate the scattering profile versus time (or range) by computing a cross correlation function between the recorded received signal and a three-state RZ PN code kernel in the receiver. The method also may be used for pulse delay time (i.e., PPM) communications.

  17. Elasticity of Long Distance Travelling

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    2011-01-01

    With data from the Danish expenditure survey for 12 years 1996 through 2007, this study analyses household expenditures for long distance travelling. Household expenditures are examined at two levels of aggregation having the general expenditures on transportation and leisure relative to five other...... aggregated commodities at the highest level, and the specific expenditures on plane tickets and travel packages at the lowest level. The Almost Ideal Demand System is applied to determine the relationship between expenditures on transportation and leisure and all other purchased non-durables within...... packages has higher income elasticity of demand than plane tickets but also higher than transportation and leisure in general. The findings within price sensitiveness are not as sufficient estimated, but the model results indicate that travel packages is far more price elastic than plane tickets which...

  18. Perspectives of Research on Distance Education.

    Science.gov (United States)

    Holmberg, Borje

    The history of research on distance education was studied. Major research done on distance education in such diverse areas as the United States, Venezuela, and Europe was analyzed. It was discovered that the earliest attempts to develop theories of distance education were mainly concerned with identifying its very concept. Like most educational…

  19. Rough Way for Academics: Distance Education

    Science.gov (United States)

    Gursul, Fatih

    2010-01-01

    This study aims to compare the academics' perceptions about face to face and distance education, beside finding out the contributions of distance education to them, difficulties they experience in synchronous and asynchronous distance education environments and suggestions for possible solutions of the existing problems. The sample consists of 52…

  20. Global continuation for distance geometry problems

    Energy Technology Data Exchange (ETDEWEB)

    More, J.J.; Wu, Zhijun

    1995-03-01

    Distance geometry problems arise in the interpretation of NMR data and in the determination of protein structure. The authors formulate the distance geometry problem as a global minimization problem with special structure, and show the global smoothing techniques and a continuation approach for global optimization can be used to determine solutions of distance geometry problems with a nearly 100% probability of success.

  1. Analysing designed experiments in distance sampling

    Science.gov (United States)

    Stephen T. Buckland; Robin E. Russell; Brett G. Dickson; Victoria A. Saab; Donal N. Gorman; William M. Block

    2009-01-01

    Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates...

  2. Can molecular motors drive distance measurements in injured neurons?

    Directory of Open Access Journals (Sweden)

    Naaman Kam

    2009-08-01

    Full Text Available Injury to nerve axons induces diverse responses in neuronal cell bodies, some of which are influenced by the distance from the site of injury. This suggests that neurons have the capacity to estimate the distance of the injury site from their cell body. Recent work has shown that the molecular motor dynein transports importin-mediated retrograde signaling complexes from axonal lesion sites to cell bodies, raising the question whether dynein-based mechanisms enable axonal distance estimations in injured neurons? We used computer simulations to examine mechanisms that may provide nerve cells with dynein-dependent distance assessment capabilities. A multiple-signals model was postulated based on the time delay between the arrival of two or more signals produced at the site of injury-a rapid signal carried by action potentials or similar mechanisms and slower signals carried by dynein. The time delay between the arrivals of these two types of signals should reflect the distance traversed, and simulations of this model show that it can indeed provide a basis for distance measurements in the context of nerve injuries. The analyses indicate that the suggested mechanism can allow nerve cells to discriminate between distances differing by 10% or more of their total axon length, and suggest that dynein-based retrograde signaling in neurons can be utilized for this purpose over different scales of nerves and organisms. Moreover, such a mechanism might also function in synapse to nucleus signaling in uninjured neurons. This could potentially allow a neuron to dynamically sense the relative lengths of its processes on an ongoing basis, enabling appropriate metabolic output from cell body to processes.

  3. Rotational-resonance distance measurements in multi-spin systems.

    Science.gov (United States)

    Verhoeven, Aswin; Williamson, Philip T F; Zimmermann, Herbert; Ernst, Matthias; Meier, Beat H

    2004-06-01

    It is demonstrated that internuclear distances can be evaluated from rotational-resonance (RR) experiments in uniformly (13)C-labelled compounds. The errors in the obtained distances are less than 10% without the need to know any parameters of the spin system except the isotropic chemical shifts of all spins. We describe the multi-spin system with a simple fictitious spin-1/2 model. The influence of the couplings to the passive spins (J and dipolar coupling) is described by an empirical constant offset from the rotational-resonance condition. Using simulated data for a three-spin system, we show that the two-spin model describes the rotational-resonance transfer curves well as long as none of the passive spins is close to a rotational-resonance condition with one of the active spins. The usability of the two-spin model is demonstrated experimentally using a sample of acetylcholine perchlorate with labelling schemes of various levels of complexity. Doubly-, triply-, and fully labelled compounds lead to strongly varying RR polarization-transfer curves but the evaluated distances using the two-spin model are identical within the expected error limits and coincide with the distance from the X-ray structure. Rotational-resonance distance measurements in fully labelled compounds allow, in particular, the measurement of weak couplings in the presence of strong couplings.

  4. Social distance and anonymity modulate fairness consideration: An ERP study.

    Science.gov (United States)

    Yu, Rongjun; Hu, Pan; Zhang, Ping

    2015-08-21

    Previous research indicated that fairness consideration can be influenced by social distance. However, it is not clear whether social distance and anonymity have an interactive impact on fairness evaluation during asset distribution and whether these processes can be documented in brain activity. Using a modified ultimatum game combined with measures of event related potential (ERP), we examined how social distance and anonymity modulate brain response to inequality. At the behavior level, we found that acceptance rate and reaction time can be substantially modified by social distance and anonymity. Feedback-related negativity, an ERP component associated with conflict between cognitive and emotion motives, was more negative in response to unfairness than fairness from strangers; however, it showed an opposite trend for unfair offers provided by friends, suggesting that the influence of social distance on fairness perception is relatively fast. The P300 in response to fair offers was more positive when the proposers made offers when uncertain about partner identity than when certain about partner identity. These results suggest that unfairness is evaluated in a fast conflict detection stage and a slower stage that integrates more complex social contextual factors such as anonymity.

  5. Distance Transform Based Enhancement for Linear Interpolated Images

    Institute of Scientific and Technical Information of China (English)

    唐莉萍; 曾培峰

    2003-01-01

    An approach of distance map based image enhancement (DMIE) is proposed. It is applied to conventional interpolations to get sharp images. Edge detection is performed after images are interpolated by linear interpolations. To meet the two conditions set for DMIE, i. e., no abrupt changes and no overboosting, different boosting rate should be used in adjusting pixel intensities. When the boosting rate is determined by using the distance from enhanced pixels to nearest edges, edge-oriented image enhancement is obtained. By using Erosion technique, the range for pixel intensity adjustment is set. Over-enhancement is avoided by limiting the pixel intensities in enhancement within the range.A unified linear-time algorithm for distance transform is adopted to deal with the calculation of Euclidean distance of the images. Its computation complexity is O (N2 ). After the preparation, i. e.,distance transforming and erosion, the images get more and more sharpened while no over-boosting occurs by repeating the enhancement procedure. The simplicity of the enhancement operation makes DMIE suitable for enhancement rate adjusting.

  6. Social distance and anonymity modulate fairness consideration: An ERP study

    Science.gov (United States)

    Yu, Rongjun; Hu, Pan; Zhang, Ping

    2015-01-01

    Previous research indicated that fairness consideration can be influenced by social distance. However, it is not clear whether social distance and anonymity have an interactive impact on fairness evaluation during asset distribution and whether these processes can be documented in brain activity. Using a modified ultimatum game combined with measures of event related potential (ERP), we examined how social distance and anonymity modulate brain response to inequality. At the behavior level, we found that acceptance rate and reaction time can be substantially modified by social distance and anonymity. Feedback-related negativity, an ERP component associated with conflict between cognitive and emotion motives, was more negative in response to unfairness than fairness from strangers; however, it showed an opposite trend for unfair offers provided by friends, suggesting that the influence of social distance on fairness perception is relatively fast. The P300 in response to fair offers was more positive when the proposers made offers when uncertain about partner identity than when certain about partner identity. These results suggest that unfairness is evaluated in a fast conflict detection stage and a slower stage that integrates more complex social contextual factors such as anonymity. PMID:26293456

  7. Expected distance between terminal nucleotides of RNA secondary structures.

    Science.gov (United States)

    Clote, Peter; Ponty, Yann; Steyaert, Jean-Marc

    2012-09-01

    In "The ends of a large RNA molecule are necessarily close", Yoffe et al. (Nucleic Acids Res 39(1):292-299, 2011) used the programs RNAfold [resp. RNAsubopt] from Vienna RNA Package to calculate the distance between 5' and 3' ends of the minimum free energy secondary structure [resp. thermal equilibrium structures] of viral and random RNA sequences. Here, the 5'-3' distance is defined to be the length of the shortest path from 5' node to 3' node in the undirected graph, whose edge set consists of edges {i, i + 1} corresponding to covalent backbone bonds and of edges {i, j} corresponding to canonical base pairs. From repeated simulations and using a heuristic theoretical argument, Yoffe et al. conclude that the 5'-3' distance is less than a fixed constant, independent of RNA sequence length. In this paper, we provide a rigorous, mathematical framework to study the expected distance from 5' to 3' ends of an RNA sequence. We present recurrence relations that precisely define the expected distance from 5' to 3' ends of an RNA sequence, both for the Turner nearest neighbor energy model, as well as for a simple homopolymer model first defined by Stein and Waterman. We implement dynamic programming algorithms to compute (rather than approximate by repeated application of Vienna RNA Package) the expected distance between 5' and 3' ends of a given RNA sequence, with respect to the Turner energy model. Using methods of analytical combinatorics, that depend on complex analysis, we prove that the asymptotic expected 5'-3' distance of length n homopolymers is approximately equal to the constant 5.47211, while the asymptotic distance is 6.771096 if hairpins have a minimum of 3 unpaired bases and the probability that any two positions can form a base pair is 1/4. Finally, we analyze the 5'-3' distance for secondary structures from the STRAND database, and conclude that the 5'-3' distance is correlated with RNA sequence length.

  8. From language identification to language distance

    Science.gov (United States)

    Gamallo, Pablo; Pichel, José Ramom; Alegria, Iñaki

    2017-10-01

    In this paper, we define two quantitative distances to measure how far apart two languages are. The distance measure that we have identified as more accurate is based on the perplexity of n-gram models extracted from text corpora. An experiment to compare forty-four European languages has been performed. For this purpose, we computed the distances for all the possible language pairs and built a network whose nodes are languages and edges are distances. The network we have built on the basis of linguistic distances represents the current map of similarities and divergences among the main languages of Europe.

  9. Continuity Properties of Distances for Markov Processes

    DEFF Research Database (Denmark)

    Jaeger, Manfred; Mao, Hua; Larsen, Kim Guldstrand

    2014-01-01

    In this paper we investigate distance functions on finite state Markov processes that measure the behavioural similarity of non-bisimilar processes. We consider both probabilistic bisimilarity metrics, and trace-based distances derived from standard Lp and Kullback-Leibler distances. Two desirable...... continuity properties for such distances are identified. We then establish a number of results that show that these two properties are in conflict, and not simultaneously fulfilled by any of our candidate natural distance functions. An impossibility result is derived that explains to some extent...

  10. Kinematic Distance of Galactic Planetary Nebulae

    CERN Document Server

    Yang, A Y; Zhu, H; Leahy, D A; Wu, D

    2016-01-01

    We construct \\HI~absorption spectra for 18 planetary nebulae (PNe) and their background sources using the data from the International Galactic Plane Survey. We estimate the kinematic distances of these PNe, among which 15 objects' kinematic distances are obtained for the first time. The distance uncertainties of 13 PNe range from 10% to 50%, which is a significant improvement with uncertainties of a factor two or three smaller than most of previous distance measurements. We confirm that PN G030.2-00.1 is not a PN because of its large distance found here.

  11. Learner characteristics involved in distance learning

    Energy Technology Data Exchange (ETDEWEB)

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  12. Critical Points in Distance Learning System

    Directory of Open Access Journals (Sweden)

    Airina Savickaitė

    2013-08-01

    Full Text Available Purpose – This article presents the results of distance learning system analysis, i.e. the critical elements of the distance learning system. The critical points of distance learning are a part of distance education online environment interactivity/community process model. The most important is the fact that the critical point is associated with distance learning participants. Design/methodology/approach – Comparative review of articles and analysis of distance learning module. Findings – A modern man is a lifelong learner and distance learning is a way to be a modern person. The focus on a learner and feedback is the most important thing of learning distance system. Also, attention should be paid to the lecture-appropriate knowledge and ability to convey information. Distance system adaptation is the way to improve the learner’s learning outcomes. Research limitations/implications – Different learning disciplines and learning methods may have different critical points. Practical implications – The information of analysis could be important for both lecturers and students, who studies distance education systems. There are familiar critical points which may deteriorate the quality of learning. Originality/value – The study sought to develop remote systems for applications in order to improve the quality of knowledge. Keywords: distance learning, process model, critical points. Research type: review of literature and general overview.

  13. FUZZY-DISTANCE FUNCTION APPROACH FOR MULTIPLE CRITERIA DECISION MAKING

    Directory of Open Access Journals (Sweden)

    Mayank Kumar

    2012-06-01

    Full Text Available In this paper, a method for decision making using fuzzy integral and distance function is presented. Case studies of multiple-response process with correlated responses are used to illustrate the effective application of the proposed approach. The efficacy of this method is compared with the existing methods of MCDM like TOPSIS and GRA. The proposed method is robust, requires less information and less complex as compared to many existing methods.

  14. Distance Education at Silesian University of Technology

    Directory of Open Access Journals (Sweden)

    Piotr Klosowski

    2008-12-01

    Full Text Available This paper presents Distance Learning Platform used by Silesian University of Technology. Distance Learning Platform is based on modular object-oriented dynamic learning environment, represents LMS (Learning Management Systems technology, a software package designed to help educators create quality online courses. Currently on Distance Learning Platform at Silesian University of Technology are available over 520 online courses created for students of twelve University's faculties. Number of Distance Learning Platform users exceeds 12000. Distance Learning Platform works as typically asynchronous e-learning service, but in the future more synchronous e-learning services will be added. Distance Learning Platform has great potential to create a successful elearning experience by providing a plethora of excellent tools that can be used to enhance conventional classroom instruction, in hybrid courses, or any distance learning arrangements.

  15. Distance Education at Silesian University of Technology

    Directory of Open Access Journals (Sweden)

    Piotr Klosowski

    2008-12-01

    Full Text Available This paper presents Distance Learning Platform used by Silesian University of Technology. Distance Learning Platform is based on modular object-oriented dynamic learning environment, represents LMS (Learning Management Systems technology, a software package designed to help educators create quality online courses. Currently on Distance Learning Platform at Silesian University of Technology are available over 520 online courses created for students of twelve University's faculties. Number of Distance Learning Platform users exceeds 12000. Distance Learning Platform works as typically asynchronous e-learning service, but in the future more synchronous e-learning services will be added. Distance Learning Platform has great potential to create a successful elearning experience by providing a plethora of excellent tools that can be used to enhance conventional classroom instruction, in hybrid courses, or any distance learning arrangements.

  16. The Gould’s Belt Distances Survey (GOBELINS) II. Distances and Structure toward the Orion Molecular Clouds

    Science.gov (United States)

    Kounkel, Marina; Hartmann, Lee; Loinard, Laurent; Ortiz-León, Gisela N.; Mioduszewski, Amy J.; Rodríguez, Luis F.; Dzib, Sergio A.; Torres, Rosa M.; Pech, Gerardo; Galli, Phillip A. B.; Rivera, Juana L.; Boden, Andrew F.; Evans, Neal J., II; Briceño, Cesar; Tobin, John J.

    2017-01-01

    We present the results of the Gould’s Belt Distances Survey of young star-forming regions toward the Orion Molecular Cloud Complex. We detected 36 young stellar objects (YSOs) with the Very Large Baseline Array, 27 of which have been observed in at least three epochs over the course of two years. At least half of these YSOs belong to multiple systems. We obtained parallax and proper motions toward these stars to study the structure and kinematics of the Complex. We measured a distance of 388 ± 5 pc toward the Orion Nebula Cluster, 428 ± 10 pc toward the southern portion L1641, 388 ± 10 pc toward NGC 2068, and roughly ∼420 pc toward NGC 2024. Finally, we observed a strong degree of plasma radio scattering toward λ Ori.

  17. Open and Distance Learning Today. Routledge Studies in Distance Education Series.

    Science.gov (United States)

    Lockwood, Fred, Ed.

    This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American Distance Education" (Moore); "Creating the…

  18. Fast Exact Euclidean Distance (FEED): A New Class of Adaptable Distance Transforms.

    Science.gov (United States)

    Schouten, Theo E; van den Broek, Egon L

    2014-11-01

    A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast exact euclidean distance (FEED) transforms. FEED class algorithms calculate the DT starting-directly from the definition or rather its inverse. The principle of FEED class algorithms is introduced, followed by strategies for their efficient implementation. It is shown that FEED class algorithms unite properties of ordered propagation, raster scanning, and independent scanning DT. Moreover, FEED class algorithms shown to have a unique property: they can be tailored to the images under investigation. Benchmarks are conducted on both the Fabbri et al. data set and on a newly developed data set. Three baseline, three approximate, and three state-of-the-art DT algorithms were included, in addition to two implementations of FEED class algorithms. It illustrates that FEED class algorithms i) provide truly exact Euclidean DT; ii) do no suffer from disconnected Voronoi tiles, which is a unique feature for non-parallel but fast DT; iii) outperform any other approximate and exact Euclidean DT with its time complexity O(N), even after their optimization; and iv) are unequaled in that they can be adapted to the characteristics of the image class at hand.

  19. Lithological Uncertainty Expressed by Normalized Compression Distance

    Science.gov (United States)

    Jatnieks, J.; Saks, T.; Delina, A.; Popovs, K.

    2012-04-01

    Lithological composition and structure of the Quaternary deposits is highly complex and heterogeneous in nature, especially as described in borehole log data. This work aims to develop a universal solution for quantifying uncertainty based on mutual information shared between the borehole logs. This approach presents tangible information directly useful in generalization of the geometry and lithology of the Quaternary sediments for use in regional groundwater flow models as a qualitative estimate of lithological uncertainty involving thousands of borehole logs would be humanly impossible due to the amount of raw data involved. Our aim is to improve parametrization of recharge in the Quaternary strata. This research however holds appeal for other areas of reservoir modelling, as demonstrated in the 2011 paper by Wellmann & Regenauer-Lieb. For our experiments we used extracts of the Quaternary strata from general-purpose geological borehole log database maintained by the Latvian Environment, Geology and Meteorology Centre, spanning the territory of Latvia. Lithological codes were generalised into 2 aggregation levels consisting of 5 and 20 rock types respectively. Our calculation of borehole log similarity relies on the concept of information distance proposed by Bennet et al. in 1998. This was developed into a practical data mining application by Cilibrasi in the 2007 dissertation. The resulting implementation called CompLearn utilities provide a calculation of the Normalized Compression Distance (NCD) metric. It relies on the universal data compression algorithms for estimating mutual information content in the data. This approach has proven to be universally successful for parameter free data mining in disciplines from molecular biology to network intrusion monitoring. To improve this approach for use in geology it is beneficial to apply several transformations as pre-processing steps to the borehole log data. Efficiency of text stream compressors, such as

  20. Long-Distance Free Fall

    Science.gov (United States)

    Gallant, Joseph

    1999-04-01

    One of the goals of physics education is to instill a sense of wonder in our students. We hope our natural curiosity will rub off on them and that they will apply the critical thinking skills we teach them to other aspects of their lives outside the classroom. As an example of this, consider the situation described in Milton's epic poem ``Paradise Lost''. Milton wrote that when the devil was cast out of heaven, he fell for nine days before landing in hell. In Milton's universe, hell is a separate place from Earth, but many people place hell at the center of the Earth. Based on these ideas, we can apply Newton's laws of motion to calculate the distance from heaven to Earth. This exercise is an example of the kind of intellectual exercise a physicist (or a physics student) might carry out when confronted with such information. We apply the basic principles of physics to a situation described in work of literature while making no attempt to validate or refute any philosophy, theology or ideology.

  1. Giant Sparks at Cosmological Distances?

    CERN Document Server

    Kulkarni, S R; Neill, J D; Zheng, Z; Juric, M

    2014-01-01

    [Abridged] Millisecond duration bright radio pulses in the 1.4-GHz band and with inferred dispersion measures (DM) well in excess of Galactic values have been reported by Lorimer et al. and Thornton et al.. The all-sky rate of these events is large, ~10^4 per day above ~1 Jy. To add to the mystery there now exists "Perytons'' -- also pulsed and dispersed sources but most certainly of local (artificial or atmospheric) origin. The suggested models now range from sources originating in the Earth's atmosphere, in stellar coronae, in other galaxies and at even cosmological distances. Using a series of physically motivated assumptions combined with the observed properties of these bursts, we explore possible constraints on sites or processes that can account for such high DMs. In our analysis, we focus on the first such reported event by Lorimer et al.: a 30 Jy, 5-ms duration burst with a dispersion measure of 375 cm^-3 pc and exhibiting a steep frequency-dependent pulse width (hereafter dubbed as the Sparker). Ass...

  2. The redshift-distance relation.

    Science.gov (United States)

    Segal, I E

    1993-06-01

    Key predictions of the Hubble law are inconsistent with direct observations on equitable complete samples of extragalactic sources in the optical, infrared, and x-ray wave bands-e.g., the predicted dispersion in apparent magnitude is persistently greatly in excess of its observed value, precluding an explanation via hypothetical perturbations or irregularities. In contrast, the predictions of the Lundmark (homogeneous quadratic) law are consistent with the observations. The Lundmark law moreover predicts the deviations between Hubble law predictions and observation with statistical consistency, while the Hubble law provides no explanation for the close fit of the Lundmark law. The flux-redshift law F [symbol, see text] (1 + z)/z appears consistent with observations on equitable complete samples in the entire observed redshift range, when due account is taken of flux limits by an optimal statistical method. Under the theoretical assumption that space is a fixed sphere, as in the Einstein universe, this law implies the redshift-distance relation z = tan2(r/2R), where R is the radius of the spherical space. This relation coincides with the prediction of chronometric cosmology, which estimates R as 160 +/- 40 Mpc (1 parsec = 3.09 x 10(16) m) from the proper motion to redshift relation of superluminal sources. Tangential aspects, including statistical methodology, fundamental physical theory, bright cluster galaxy samples, and proposed luminosity evolution, are briefly considered.

  3. THE GOULD'S BELT DISTANCE SURVEY

    Directory of Open Access Journals (Sweden)

    L. Loinard

    2011-01-01

    Full Text Available Observaciones que utilizan la interferometría de muy larga línea de base (VLBI por sus siglas en ingl´es pueden proveer la posición de radiofuentes compactas con una precisión del orden de 50 micro-segundos de arco. Esto es suficiente para medir la paralaje trigonométrica y los movimientos propios de cualquier objeto localizado hasta 500 pc del Sol con una precisión mejor que unos porcientos. Por ser magnéticamente activas, las estrellas jóvenes a menudo emiten emisión radio compacta detectable usando técnicas VLBI. Aquí, mostraremos cómo observaciones VLBI ya han restringido la distancia a las regiones de formación estelar cercanas más frecuentemente estudiadas (Tauro, Ofiuco, Orión, etc. y han empezado a revelar su estructura y su cinemática interna. Luego, describiremos un gran proyecto (llamado The Gould's Belt Distance Survey diseñado para proveer una vista detallada de la formación estelar en la vecindad Solar, usando observaciones VLBI.

  4. Social distancing strategies against disease spreading

    Science.gov (United States)

    Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

    2014-03-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e, the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

  5. LEARNING STYLES AND SATISFACTION IN DISTANCE EDUCATION

    Directory of Open Access Journals (Sweden)

    Darren C. WU

    2014-10-01

    Full Text Available Although complex, controversial, and contradicting, learning styles is highly influential. Distance education (DE has experienced tremendous growth in the last few decades. The popularity of learning styles and DE necessitates research. This correlational research study was conducted to determine if there is any evidence to incorporate learning styles in DE. The following is the research question for this study. Are students’ learning styles based on the visual, auditory, tactile model correlated to satisfaction of course format in an online undergraduate course? The participants of this study were students enrolled in three sections of the Contemporary Worldviews course at a private higher education institution (HEI. Learning styles were determined by a variant of the visual, auditory, read/write, and kinesthetic (VARK framework. Satisfaction of course format was determined from one composite question with responses based on a Likert scale. The response rate was 53.5%. Statistical analysis determined that learning styles was not correlated to satisfaction of course format in this current study. There are implications from this study that curriculum can be designed for a single course that leaves students highly satisfied. Educators should saturate DE courses with as much variance as feasible given technology and cost limitations to account for possible learning style differences.

  6. Robotic laboratory for distance education

    Science.gov (United States)

    Luciano, Sarah C.; Kost, Alan R.

    2016-09-01

    This project involves the construction of a remote-controlled laboratory experiment that can be accessed by online students. The project addresses a need to provide a laboratory experience for students who are taking online courses to be able to provide an in-class experience. The chosen task for the remote user is an optical engineering experiment, specifically aligning a spatial filter. We instrument the physical laboratory set up in Tucson, AZ at the University of Arizona. The hardware in the spatial filter experiment is augmented by motors and cameras to allow the user to remotely control the hardware. The user interacts with a software on their computer, which communicates with a server via Internet connection to the host computer in the Optics Laboratory at the University of Arizona. Our final overall system is comprised of several subsystems. These are the optical experiment set-up, which is a spatial filter experiment; the mechanical subsystem, which interfaces the motors with the micrometers to move the optical hardware; the electrical subsystem, which allows for the electrical communications from the remote computer to the host computer to the hardware; and finally the software subsystem, which is the means by which messages are communicated throughout the system. The goal of the project is to convey as much of an in-lab experience as possible by allowing the user to directly manipulate hardware and receive visual feedback in real-time. Thus, the remote user is able to learn important concepts from this particular experiment and is able to connect theory to the physical world by actually seeing the outcome of a procedure. The latter is a learning experience that is often lost with distance learning and is one that this project hopes to provide.

  7. Distance and Cable Length Measurement System

    Directory of Open Access Journals (Sweden)

    Jonay Toledo

    2009-12-01

    Full Text Available A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement.

  8. Distance and Cable Length Measurement System

    Science.gov (United States)

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  9. The Distance to the Draco Cloud

    CERN Document Server

    Gladders, M D; Burns, C R; Attard, A; Casey, M P; Hamilton, D; Mallén-Ornelas, G; Karr, J L; Poirier, S M; Sawicki, M; Barrientos, L F; Mochnacki, S W; Gladders, Michael D.; Burns, Christopher R.; Hamilton, Devon; Mallén-Ornelas, Gabriela; Poirier, Sara M.; Sawicki, Marcin; Mochnacki, Stefan W.

    1998-01-01

    The understanding of the nature of intermediate and high velocity gas in the Milky Way is hampered by a paucity of distance estimates to individual clouds. A project has been started at the David Dunlap Observatory to address this lack of distance measures by observing early-type stars along the line of sight towards these clouds and searching for sodium doublet absorption at the clouds' systemic velocities. Distances to foreground stars (no absorption) and background stars (with absorption) are estimated from spectroscopic parallax, and thus the distance to the bracketed cloud is estimated. In this Letter, we present the first result from this ongoing project, a measurement of the distance to the Draco Cloud, which is the most studied of the intermediate velocity clouds. The result presented here is the first distance bracket which tightly constrains the position of the Draco Cloud. We briefly describe our target selection and observing methodology, and then demonstrate absorption at the velocity of the Drac...

  10. Long distance signaling using axionlike particles

    Science.gov (United States)

    Stancil, Daniel D.

    2007-12-01

    The possible existence of axionlike particles could lead to a new type of long-distance communication. In this work, basic antenna concepts are defined and a Friis-like equation is derived to facilitate long-distance link calculations. An example calculation is presented showing that communication over distances of 1000 km or more may be possible for ma5×10-8GeV-1.

  11. Inverse Distance Weighted Interpolation Involving Position Shading

    OpenAIRE

    Li, Zhengquan; WU Yaoxiang

    2015-01-01

    Considering the shortcomings of inverse distance weighted (IDW) interpolation in practical applications, this study improved the IDW algorithm and put forward a new spatial interpolation method that named as adjusted inverse distance weighted (AIDW). In interpolating process, the AIDW is capable of taking into account the comprehensive influence of distance and position of sample point to interpolation point, by adding a coefficient (K) into the normal IDW formula. The coefficient (K) is used...

  12. A Cognitively Grounded Measure of Pronunciation Distance

    Science.gov (United States)

    Wieling, Martijn; Nerbonne, John; Bloem, Jelke; Gooskens, Charlotte; Heeringa, Wilbert; Baayen, R. Harald

    2014-01-01

    In this study we develop pronunciation distances based on naive discriminative learning (NDL). Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments. PMID:24416119

  13. A cognitively grounded measure of pronunciation distance.

    Science.gov (United States)

    Wieling, Martijn; Nerbonne, John; Bloem, Jelke; Gooskens, Charlotte; Heeringa, Wilbert; Baayen, R Harald

    2014-01-01

    In this study we develop pronunciation distances based on naive discriminative learning (NDL). Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments.

  14. Maximum likelihood estimates of pairwise rearrangement distances.

    Science.gov (United States)

    Serdoz, Stuart; Egri-Nagy, Attila; Sumner, Jeremy; Holland, Barbara R; Jarvis, Peter D; Tanaka, Mark M; Francis, Andrew R

    2017-06-21

    Accurate estimation of evolutionary distances between taxa is important for many phylogenetic reconstruction methods. Distances can be estimated using a range of different evolutionary models, from single nucleotide polymorphisms to large-scale genome rearrangements. Corresponding corrections for genome rearrangement distances fall into 3 categories: Empirical computational studies, Bayesian/MCMC approaches, and combinatorial approaches. Here, we introduce a maximum likelihood estimator for the inversion distance between a pair of genomes, using a group-theoretic approach to modelling inversions introduced recently. This MLE functions as a corrected distance: in particular, we show that because of the way sequences of inversions interact with each other, it is quite possible for minimal distance and MLE distance to differently order the distances of two genomes from a third. The second aspect tackles the problem of accounting for the symmetries of circular arrangements. While, generally, a frame of reference is locked, and all computation made accordingly, this work incorporates the action of the dihedral group so that distance estimates are free from any a priori frame of reference. The philosophy of accounting for symmetries can be applied to any existing correction method, for which examples are offered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. A cognitively grounded measure of pronunciation distance.

    Directory of Open Access Journals (Sweden)

    Martijn Wieling

    Full Text Available In this study we develop pronunciation distances based on naive discriminative learning (NDL. Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments.

  16. A virtual computer lab for distance biomedical technology education

    Science.gov (United States)

    Locatis, Craig; Vega, Anibal; Bhagwat, Medha; Liu, Wei-Li; Conde, Jose

    2008-01-01

    Background The National Library of Medicine's National Center for Biotechnology Information offers mini-courses which entail applying concepts in biochemistry and genetics to search genomics databases and other information sources. They are highly interactive and involve use of 3D molecular visualization software that can be computationally taxing. Methods Methods were devised to offer the courses at a distance so as to provide as much functionality of a computer lab as possible, the venue where they are normally taught. The methods, which can be employed with varied videoconferencing technology and desktop sharing software, were used to deliver mini-courses at a distance in pilot applications where students could see demonstrations by the instructor and the instructor could observe and interact with students working at their remote desktops. Results Student ratings of the learning experience and comments to open ended questions were similar to those when the courses are offered face to face. The real time interaction and the instructor's ability to access student desktops from a distance in order to provide individual assistance and feedback were considered invaluable. Conclusion The technologies and methods mimic much of the functionality of computer labs and may be usefully applied in any context where content changes frequently, training needs to be offered on complex computer applications at a distance in real time, and where it is necessary for the instructor to monitor students as they work. PMID:18366629

  17. National Wind Distance Learning Collaborative

    Energy Technology Data Exchange (ETDEWEB)

    Dr. James B. Beddow

    2013-03-29

    Executive Summary The energy development assumptions identified in the Department of Energy's position paper, 20% Wind Energy by 2030, projected an exploding demand for wind energy-related workforce development. These primary assumptions drove a secondary set of assumptions that early stage wind industry workforce development and training paradigms would need to undergo significant change if the workforce needs were to be met. The current training practice and culture within the wind industry is driven by a relatively small number of experts with deep field experience and knowledge. The current training methodology is dominated by face-to-face, classroom based, instructor present training. Given these assumptions and learning paradigms, the purpose of the National Wind Distance Learning Collaborative was to determine the feasibility of developing online learning strategies and products focused on training wind technicians. The initial project scope centered on (1) identifying resources that would be needed for development of subject matter and course design/delivery strategies for industry-based (non-academic) training, and (2) development of an appropriate Learning Management System (LMS). As the project unfolded, the initial scope was expanded to include development of learning products and the addition of an academic-based training partner. The core partners included two training entities, industry-based Airstreams Renewables and academic-based Lake Area Technical Institute. A third partner, Vision Video Interactive, Inc. provided technology-based learning platforms (hardware and software). The revised scope yielded an expanded set of results beyond the initial expectation. Eight learning modules were developed for the industry-based Electrical Safety course. These modules were subsequently redesigned and repurposed for test application in an academic setting. Software and hardware developments during the project's timeframe enabled redesign providing

  18. Research on Distance Education Development in China

    Science.gov (United States)

    Xin, Ding; Jian, Niu; Yanhui, Han

    2010-01-01

    Distance education is among the significant fields for the application of educational technology. Distance education in China has gone through three phases, namely: correspondence-based education, radio and TV-based education and online education. This paper was based on educational technology application, and the historical, dialectic and…

  19. Binding Principle for Long-Distance Anaphors.

    Science.gov (United States)

    Choi, Dong-Ik

    1997-01-01

    An analysis of long-distance anaphora, a binding phenomenon in which reflexives find their antecedents outside their local domain, is presented, using data from English, Chinese, Japanese, Korean, Russian, Icelandic, and Italian. It is found that no approach deals with long-distance anaphors exclusively and elegantly. The binding domain…

  20. Isolation by language and distance in Belgium.

    Science.gov (United States)

    Barrai, I; Rodriguez-Larralde, A; Manni, F; Ruggiero, V; Tartari, D; Scapoli, C

    2004-01-01

    The isonymy structure of trilingual Belgium was studied using the surname distributions for 1,118,004 private telephone users. The users were distributed in 77 Flemish, 76 French, and 3 German speaking towns, selected on a geographic basis to form an approximately regular grid over Belgium. Lasker's distance was found to be considerably higher between languages than within languages. For the whole of Belgium, irrespective of language, it was highly correlated with linear geographic distance, with r = 0.721+/-0.014, which is the highest correlation observed in European countries to date. Within Belgium and within languages, the correlation was highest among the Flemish (r = 0.878 +/- 0.007), and lowest among the French (r = 0.631+/-0.020). Isolation by distance in Belgium is the highest we have found in Europe, and as high as in Switzerland where the different languages are separated by geographical barriers. This is not the case in Belgium, so that the considerable isolating power of languages emerges clearly from the present analysis. From the comparison of Lasker's distance between (9.48) and within (8.16) languages, and from its regression over geographic distance (b = 0.01206), it was possible to establish a quantitative relationship between the isolating power of languages and that of geographic distance as (9.48-8.16)/0.01206 = 109 kilometres. This transformation of language distance into an equivalent geographic distance, given here for Belgium, can be applied to any similar geo-linguistic situation.

  1. Language Distance Learning for the Digital Generation

    Science.gov (United States)

    Duran-Cerda, Dolores

    2010-01-01

    The purpose of this article was to shed light on the potential of distance learning to overcome challenges in distance, space, time, and human and economic resources that limit access to language learning opportunities in cultural, literary, historical, geographical, and cross-cultural frames. Language and literature educators collectively have…

  2. Designing legible fonts for distance reading

    DEFF Research Database (Denmark)

    Beier, Sofie

    2016-01-01

    This chapter reviews existing knowledge on distance legibility of fonts, and finds that for optimal distance reading, letters and numbers benefit from relative wide shapes, open inner counters and a large x-height; fonts should further be widely spaced, and the weight should not be too heavy or t...

  3. Sensor Network Localization with Imprecise Distances

    NARCIS (Netherlands)

    Cao, M.; Morse, A.S.; Anderson, B.D.O.

    2006-01-01

    An approach to formulate geometric relations among distances between nodes as equality constraints is introduced in this paper to study the localization problem with imprecise distance information in sensor networks. These constraints can be further used to formulate optimization problems for distan

  4. A Survey on Distance Vector Routing Protocols

    CERN Document Server

    Tang, Linpeng

    2011-01-01

    In this paper we give a brief introduction to five different distance vector routing protocols (RIP, AODV, EIGRP, RIP-MTI and Babel) and give some of our thoughts on how to solve the count to infinity problem. Our focus is how distance vector routing protocols, based on limited information, can prevent routing loops and the count to infinity problem.

  5. Who Graduates from Irish Distance University Education?

    Science.gov (United States)

    Delaney, Lorraine

    2015-01-01

    This paper outlines results from an online survey of recent distance graduates. The study, based in Dublin City University (DCU) addresses a gap in the research on this cohort of graduates. Findings indicate that distance graduates are primarily from lower socio economic backgrounds, a group largely under-represented in full-time university…

  6. Distance Education for People with Visual Impairments

    Science.gov (United States)

    Liakou, Maria; Manousou, Evaggelia

    2015-01-01

    This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

  7. Audiences and Providers of Distance Education

    Science.gov (United States)

    Nazarinia Roy, R. Roudi; Schumm, Walter R.

    2011-01-01

    As noted by Moore (2007, xxiii), the fifth section of the second edition of the "Handbook of Distance Education" focused on "some of the main consumers and suppliers of distance education programs," including elementary and secondary education, community colleges, universities, the corporate sector, continuing professional…

  8. Investigating Distance Education Students' Study Skills

    Science.gov (United States)

    Poyraz, Cengiz

    2013-01-01

    Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at…

  9. Applying Leadership Theories to Distance Education Leadership

    Science.gov (United States)

    Nworie, John

    2012-01-01

    The instructional delivery mode in distance education has been transitioning from the context of a physical classroom environment to a virtual learning environment or maintaining a hybrid of the two. However, most distance education programs in dual mode institutions are situated in traditional face-to-face instructional settings. Distance…

  10. Distance Education Report, 2011-2012

    Science.gov (United States)

    California Community Colleges, Chancellor's Office, 2013

    2013-01-01

    This is a report on distance education in the California Community College. This is the seventh report to the California Community Colleges Board of Governors (BOG) per BOG Standing Order 409 (b) "that evaluates the effectiveness of distance education and education technology system wide and provides analysis of data demographically (by age,…

  11. Three Generations of Distance Education Pedagogy

    Science.gov (United States)

    Anderson, Terry; Dron, Jon

    2011-01-01

    This paper defines and examines three generations of distance education pedagogy. Unlike earlier classifications of distance education based on the technology used, this analysis focuses on the pedagogy that defines the learning experiences encapsulated in the learning design. The three generations of cognitive-behaviourist, social constructivist,…

  12. Institutional and specialized Distance learning program accreditation

    Directory of Open Access Journals (Sweden)

    Mehzabul Hoque Nahid

    2015-09-01

    Full Text Available Teaching and learning are no longer confined to the classroom or the school day. There are many technologies that can offer a great deal of flexibility in when, where, and how education is distributed. The Teacher's Guide to Distance Learning is intended for K-12 educators who are interested in implementing distance learning technologies. It provides an overview of the advantages and characteristics of the various technologies now being used to reach remote learners. Distance learning provides "access to learning when the source of information and the learners are separated by time and distance, or both." Distance education courses that require a physical on-site presence for any reason (excluding taking examinations may be referred to as hybrid or blended courses of study. Massive open online courses (MOOCs, aimed at large-scale interactive participation and open access via the web or other network technologies, are recent developments in distance education. A number of other terms are used roughly synonymously with distance education. However distance is the oldest and mostly commonly used term globally. It is also the broadest term and has the largest collection of related research articles. The main objective of this paper is develop an understanding of the characteristics and needs of distant students with little first-hand experience and limited, if any, face-to-face contact.

  13. When Do Distance Effects Become Empirically Observable?

    DEFF Research Database (Denmark)

    Beugelsdijk, Sjoerd; Nell, Phillip C.; Ambos, Björn

    2017-01-01

    , on average, distance is unrelated to value added by headquarters but that this effect is contingent upon the extent to which the subsidiary is locally embedded. Only after a certain threshold level of subsidiary embeddedness, distance is negatively related to headquarters value added. This effect is more...

  14. Measuring Distances to Remote Galaxies and Quasars.

    Science.gov (United States)

    McCarthy, Patrick J.

    1988-01-01

    Describes the use of spectroscopy and the redshift to measure how far an object is by measuring how fast it is receding from earth. Lists the most distant quasars yet found. Tables include "Redshift vs. Distance" and "Distances to Celestial Objects for Various Cosmologies." (CW)

  15. NASA Langley/CNU Distance Learning Programs.

    Science.gov (United States)

    Caton, Randall; Pinelli, Thomas E.

    NASA Langley Research Center and Christopher Newport University (CNU) provide, free to the public, distance learning programs that focus on math, science, and/or technology over a spectrum of education levels from K-adult. The effort started in 1997, and currently there are a suite of five distance-learning programs. This paper presents the major…

  16. Measuring Norwegian dialect distances using acoustic features

    NARCIS (Netherlands)

    Heeringa, Wilbert; Johnson, Keith; Gooskens, Charlotte

    2009-01-01

    Levenshtein distance has become a popular tool for measuring linguistic dialect distances, and has been applied to Irish Gaelic, Dutch, German and other dialect groups. The method, in the current state of the art, depends upon phonetic transcriptions, even when acoustic differences are used the numb

  17. Spectral distance on the Moyal plane

    Energy Technology Data Exchange (ETDEWEB)

    Martinetti, Pierre [Universitaet Goettingen (Germany). Courant Centre

    2010-07-01

    We compute the spectral distance, defined in Connes' noncommutative geometry, in the Moyal plane. We find that the distance between the eigenstates m,m+1 of the quantum harmonic oscillator is proportional to m{sup -1/2}. We also show how to truncate the Moyal spectral triple in order to obtain quantum metric spaces in the sense of Rieffel.

  18. Applying Leadership Theories to Distance Education Leadership

    Science.gov (United States)

    Nworie, John

    2012-01-01

    The instructional delivery mode in distance education has been transitioning from the context of a physical classroom environment to a virtual learning environment or maintaining a hybrid of the two. However, most distance education programs in dual mode institutions are situated in traditional face-to-face instructional settings. Distance…

  19. Cultural Distance Asymmetry in Expatriate Adjustment

    DEFF Research Database (Denmark)

    Selmer, Jan; Chiu, Randy K.; Shenkar, Oded

    2007-01-01

    Purpose - The current literature implicitly assumes a symmetric impact of cultural distance (CD) on expatriate adjustment. By using distance as a predictor of adjustment, the literature has rendered the direction of the flow irrelevant: a US expatriate in Germany is presumed to face the same hurd...

  20. Cosmological distance indicators by coalescing binaries

    CERN Document Server

    De Laurentis, Mariafelicia; De Martino, Ivan; Formisano, Michelangelo

    2011-01-01

    Gravitational waves detected from well-localized inspiraling binaries would allow to determine, directly and independently, both binary luminosity and redshift. In this case, such systems could behave as "standard candles" providing an excellent probe of cosmic distances up to z < 0.1 and thus complementing other indicators of cosmological distance ladder.

  1. Distance Education for People with Visual Impairments

    Science.gov (United States)

    Liakou, Maria; Manousou, Evaggelia

    2015-01-01

    This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

  2. Introduction : The Metaphor of Historical Distance

    NARCIS (Netherlands)

    Den Hollander, Jaap; Paul, Herman; Peters, Rik

    2011-01-01

    What does "historical distance" mean? Starting with Johan Huizinga, the famous Dutch historian who refused to lecture on contemporary history, this introductory article argues that "historical distance" is a metaphor used in a variety of intellectual contexts. Accordingly, the metaphor has ontologic

  3. Exploring Cloud Computing for Distance Learning

    Science.gov (United States)

    He, Wu; Cernusca, Dan; Abdous, M'hammed

    2011-01-01

    The use of distance courses in learning is growing exponentially. To better support faculty and students for teaching and learning, distance learning programs need to constantly innovate and optimize their IT infrastructures. The new IT paradigm called "cloud computing" has the potential to transform the way that IT resources are utilized and…

  4. Distance Education in India Present and Future.

    Science.gov (United States)

    Datt, Ruddar

    Distance education is offered by 4 universities and 34 institutes/directorates in India. All open universities have been brought under the direction of the Indira Gandhi National Open University with regard to networking and determination of grants. The networking has avoided unnecessary duplication of course preparation costs. Distance education…

  5. Challenges Encountered by a Distance Learning Organisation

    Science.gov (United States)

    Malik, Sangeeta

    2012-01-01

    Distance learning as the name indicates is a learning, learner gets from distant places. In this learning system, learner and educators are separated by space & time. Lots of distance learning organizations are spreading to meet the increased demand of current & future needs of adult education. The rapid spread of these organizations doesn't mean…

  6. Effects of Distance Learning on Learning Effectiveness

    Science.gov (United States)

    Liu, Hong-Cheng; Yen, Jih-Rong

    2014-01-01

    The development of computers in the past two decades has resulted in the changes of education in enterprises and schools. The advance of computer hardware and platforms allow colleges generally applying distance courses to instruction that both Ministry of Education and colleges have paid attention to the development of Distance Learning. To…

  7. Key Instructional Design Elements for Distance Education.

    Science.gov (United States)

    Zheng, Lihua; Smaldino, Sharon

    2003-01-01

    Suggests that distance education instructors need to understand and apply important instructional design elements in order to successfully fulfill their role as instructional designers. Reviews the most recent literature pertaining to designing instruction in distance education. Identifies some key instructional design elements for teaching at a…

  8. Measuring Norwegian dialect distances using acoustic features

    NARCIS (Netherlands)

    Heeringa, Wilbert; Johnson, Keith; Gooskens, Charlotte

    Levenshtein distance has become a popular tool for measuring linguistic dialect distances, and has been applied to Irish Gaelic, Dutch, German and other dialect groups. The method, in the current state of the art, depends upon phonetic transcriptions, even when acoustic differences are used the

  9. Modes of Production: Fordism and Distance Education.

    Science.gov (United States)

    Farnes, Nick

    1993-01-01

    Analyzes the historical development of economic and educational systems and considers the relationship between industrialization and distance education. Modes of production and stages of conventional and distance education development are described, and future possibilities of mass higher and continuing education through the use of computer-based…

  10. Exploring Cloud Computing for Distance Learning

    Science.gov (United States)

    He, Wu; Cernusca, Dan; Abdous, M'hammed

    2011-01-01

    The use of distance courses in learning is growing exponentially. To better support faculty and students for teaching and learning, distance learning programs need to constantly innovate and optimize their IT infrastructures. The new IT paradigm called "cloud computing" has the potential to transform the way that IT resources are utilized and…

  11. A Roman Dodecahedron for measuring distance

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    Here I am discussing a possible use of a Roman Dodecahedron, a bronze artifact of gallo-roman origin, for measuring distance. A dodecahedron, found at Jublains, the ancient Nouiodunum, dating from the 2nd or 3rd century AD, is used to create a model. Looking through the model, it is possible to test it for measurements of distance based on similar triangles.

  12. New Strategy of the Distance Education

    Science.gov (United States)

    Bunyatova, Fatma Khanim; Salamov, Gulbala

    2014-01-01

    This article is dedicated to new strategy of distance education. The article deals with the possibilities of ICT (Information and Communication Technologies) in teaching specially distance education. In the article, ICT technological tools and their methods of application in educational process are looked over; discrepancy of intellectual…

  13. DISTANCES IN THE SPACES OF STATISTICAL DATA

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2014-09-01

    Full Text Available The core of applied statistics is statistics in spaces of arbitrary nature, based on the use of distances and optimization problems. This article discusses the various distances in spaces of statistical data, in particular, their conclusions on the basis of appropriate systems of axioms. The conditions and proofs of theorems first published in scientific periodicals

  14. Three Generations of Distance Education Pedagogy

    Directory of Open Access Journals (Sweden)

    Terry Anderson

    2011-03-01

    Full Text Available This paper defines and examines three generations of distance education pedagogy. Unlike earlier classifications of distance education based on the technology used, this analysis focuses on the pedagogy that defines the learning experiences encapsulated in the learning design. The three generations of cognitive-behaviourist, social constructivist, and connectivist pedagogy are examined, using the familiar community of inquiry model (Garrison, Anderson, & Archer, 2000 with its focus on social, cognitive, and teaching presences. Although this typology of pedagogies could also be usefully applied to campus-based education, the need for and practice of openness and explicitness in distance education content and process makes the work especially relevant to distance education designers, teachers, and developers. The article concludes that high-quality distance education exploits all three generations as determined by the learning content, context, and learning expectations.

  15. Automatic analysis of distance bounding protocols

    CERN Document Server

    Malladi, Sreekanth; Kothapalli, Kishore

    2010-01-01

    Distance bounding protocols are used by nodes in wireless networks to calculate upper bounds on their distances to other nodes. However, dishonest nodes in the network can turn the calculations both illegitimate and inaccurate when they participate in protocol executions. It is important to analyze protocols for the possibility of such violations. Past efforts to analyze distance bounding protocols have only been manual. However, automated approaches are important since they are quite likely to find flaws that manual approaches cannot, as witnessed in literature for analysis pertaining to key establishment protocols. In this paper, we use the constraint solver tool to automatically analyze distance bounding protocols. We first formulate a new trace property called Secure Distance Bounding (SDB) that protocol executions must satisfy. We then classify the scenarios in which these protocols can operate considering the (dis)honesty of nodes and location of the attacker in the network. Finally, we extend the const...

  16. Simple expressions for the long walk distance

    CERN Document Server

    Chebotarev, Pavel; Balaji, R

    2011-01-01

    The walk distances in graphs are defined as the result of appropriate transformations of the $\\sum_{k=0}^\\infty(tA)^k$ proximity measures, where $A$ is the weighted adjacency matrix of a connected weighted graph and $t$ is a sufficiently small positive parameter. The walk distances are graph-geodetic, moreover, they converge to the shortest path distance and to the so-called long walk distance as the parameter $t$ approaches its limiting values. In this paper, simple expressions for the long walk distance are obtained. They involve the generalized inverse, minors, and inverses of submatrices of the symmetric irreducible singular M-matrix ${\\cal L}=\\rho I-A,$ where $\\rho$ is the Perron root of $A.$

  17. Distance Learning. Volume II: Course Analysis Manual for Conversion to Distance Learning.

    Science.gov (United States)

    1998-09-01

    The primary focus of this project is the determination of the feasibility and cost effectiveness of applying Distance Learning strategies to 22...selected PPSCP courses and development of a Distance Learning Analysis Procedures Manual.

  18. The ideal subject distance for passport pictures.

    Science.gov (United States)

    Verhoff, Marcel A; Witzel, Carsten; Kreutz, Kerstin; Ramsthaler, Frank

    2008-07-04

    In an age of global combat against terrorism, the recognition and identification of people on document images is of increasing significance. Experiments and calculations have shown that the camera-to-subject distance - not the focal length of the lens - can have a significant effect on facial proportions. Modern passport pictures should be able to function as a reference image for automatic and manual picture comparisons. This requires a defined subject distance. It is completely unclear which subject distance, in the taking of passport photographs, is ideal for the recognition of the actual person. We show here that the camera-to-subject distance that is perceived as ideal is dependent on the face being photographed, even if the distance of 2m was most frequently preferred. So far the problem of the ideal camera-to-subject distance for faces has only been approached through technical calculations. We have, for the first time, answered this question experimentally with a double-blind experiment. Even if there is apparently no ideal camera-to-subject distance valid for every face, 2m can be proposed as ideal for the taking of passport pictures. The first step would actually be the determination of a camera-to-subject distance for the taking of passport pictures within the standards. From an anthropological point of view it would be interesting to find out which facial features allow the preference of a shorter camera-to-subject distance and which allow the preference of a longer camera-to-subject distance.

  19. On Properties of the Generalized Wasserstein Distance

    Science.gov (United States)

    Piccoli, Benedetto; Rossi, Francesco

    2016-12-01

    The Wasserstein distances W p ( p {≥q} 1), defined in terms of a solution to the Monge-Kantorovich problem, are known to be a useful tool to investigate transport equations. In particular, the Benamou-Brenier formula characterizes the square of the Wasserstein distance W 2 as the infimum of the kinetic energy, or action functional, of all vector fields transporting one measure to the other. Another important property of the Wasserstein distances is the Kantorovich-Rubinstein duality, stating the equality between the distance W 1( μ, ν) of two probability measures μ, ν and the supremum of the integrals in d( μ - ν) of Lipschitz continuous functions with Lipschitz constant bounded by one. An intrinsic limitation of Wasserstein distances is the fact that they are defined only between measures having the same mass. To overcome such a limitation, we recently introduced the generalized Wasserstein distances {W_p^{a,b}}, defined in terms of both the classical Wasserstein distance W p and the total variation (or L 1) distance, see (Piccoli and Rossi in Archive for Rational Mechanics and Analysis 211(1):335-358, 2014). Here p plays the same role as for the classic Wasserstein distance, while a and b are weights for the transport and the total variation term. In this paper we prove two important properties of the generalized Wasserstein distances: (1) a generalized Benamou-Brenier formula providing the equality between {W_2^{a,b}} and the supremum of an action functional, which includes a transport term (kinetic energy) and a source term; (2) a duality à la Kantorovich-Rubinstein establishing the equality between {W_1^{1,1}} and the flat metric.

  20. Distance Adaptive Tensor Discriminative Geometry Preserving Projection for Face Recognition

    Directory of Open Access Journals (Sweden)

    Ziqiang Wang

    2012-09-01

    Full Text Available There is a growing interest in dimensionality reduction techniques for face recognition, however, the traditional dimensionality reduction algorithms often transform the input face image data into vectors before embedding. Such vectorization often ignores the underlying data structure and leads to higher computational complexity. To effectively cope with these problems, a novel dimensionality reduction algorithm termed distance adaptive tensor discriminative geometry preserving projection (DATDGPP is proposed in this paper. The key idea of DATDGPP is as follows: first, the face image data are directly encoded in high‐order tensor structure so that the relationships among the face image data can be preserved; second, the data‐adaptive tensor distance is adopted to model the correlation among different coordinates of tensor data; third, the transformation matrix which can preserve discrimination and local geometry information is obtained by an iteration algorithm. Experimental results on three face databases show that the proposed algorithm outperforms other representative dimensionality reduction algorithms.

  1. Sorting Pairs of Points Based on Their Distances

    Directory of Open Access Journals (Sweden)

    Mohammad Farshi

    2016-02-01

    Full Text Available Sorting data is one of the main problems in computer science which studied vastly and used in several places. In several geometric problems, like problems on point sets or lines in the plane or Euclidean space with higher dimensions, the problem of sorting pairs of points based on the distance (between them is used. Using general sorting algorithms, sorting n 2 distances between n points can be done in O(n2 log n time. Ofcourse, sorting (n2 independent numbers does not have a faster solution, but since we have dependency between numbers in this case, finding a faster algorithm or showing that the problem in this case has O(n2 log n time complexity is interesting. In this paper, we try to answer this question.

  2. Partner Power: A study of two distance education consortia

    Directory of Open Access Journals (Sweden)

    Anne Banks Pidduck

    2006-12-01

    Full Text Available This research reports findings from a study which explored the process and criteria of partner selection – how and why partners are chosen – for two distance education consortia. The researchers reviewed recent literature on partnerships and partner selection. Two Canada-wide distance education consortia were identified as large-scale case studies for investigation of the research theory. A total of 34 informants were contacted. Written business plans, contracts, documents, partner network diagrams, and 231 archival emails from 36 correspondents were collected and analyzed for the two consortia. The research identified four criteria that influence why specific partners are chosen: requirements, resource availability, social network, and reputation. These findings suggest that the formation of partnerships and the process of partner selection are both very complex.

  3. Particle swarm optimization for determining shortest distance to voltage collapse

    Energy Technology Data Exchange (ETDEWEB)

    Arya, L.D.; Choube, S.C. [Electrical Engineering Department, S.G.S.I.T.S. Indore, MP 452 003 (India); Shrivastava, M. [Electrical Engineering Department, Government Engineering College Ujjain, MP 456 010 (India); Kothari, D.P. [Centre for Energy Studies, Indian Institute of Technology, Delhi (India)

    2007-12-15

    This paper describes an algorithm for computing shortest distance to voltage collapse or determination of CSNBP using PSO technique. A direction along CSNBP gives conservative results from voltage security view point. This information is useful to the operator to steer the system away from this point by taking corrective actions. The distance to a closest bifurcation is a minimum of the loadability given a slack bus or participation factors for increasing generation as the load increases. CSNBP determination has been formulated as an optimization problem to be used in PSO technique. PSO is a new evolutionary algorithm (EA) which is population based inspired by the social behavior of animals such as fish schooling and birds flocking. It can handle optimization problems with any complexity since mechanization is simple with few parameters to be tuned. The developed algorithm has been implemented on two standard test systems. (author)

  4. Distance software: design and analysis of distance sampling surveys for estimating population size.

    Science.gov (United States)

    Thomas, Len; Buckland, Stephen T; Rexstad, Eric A; Laake, Jeff L; Strindberg, Samantha; Hedley, Sharon L; Bishop, Jon Rb; Marques, Tiago A; Burnham, Kenneth P

    2010-02-01

    1.Distance sampling is a widely used technique for estimating the size or density of biological populations. Many distance sampling designs and most analyses use the software Distance.2.We briefly review distance sampling and its assumptions, outline the history, structure and capabilities of Distance, and provide hints on its use.3.Good survey design is a crucial prerequisite for obtaining reliable results. Distance has a survey design engine, with a built-in geographic information system, that allows properties of different proposed designs to be examined via simulation, and survey plans to be generated.4.A first step in analysis of distance sampling data is modelling the probability of detection. Distance contains three increasingly sophisticated analysis engines for this: conventional distance sampling, which models detection probability as a function of distance from the transect and assumes all objects at zero distance are detected; multiple-covariate distance sampling, which allows covariates in addition to distance; and mark-recapture distance sampling, which relaxes the assumption of certain detection at zero distance.5.All three engines allow estimation of density or abundance, stratified if required, with associated measures of precision calculated either analytically or via the bootstrap.6.Advanced analysis topics covered include the use of multipliers to allow analysis of indirect surveys (such as dung or nest surveys), the density surface modelling analysis engine for spatial and habitat modelling, and information about accessing the analysis engines directly from other software.7.Synthesis and applications. Distance sampling is a key method for producing abundance and density estimates in challenging field conditions. The theory underlying the methods continues to expand to cope with realistic estimation situations. In step with theoretical developments, state-of-the-art software that implements these methods is described that makes the methods

  5. Rethinking Distance Learning Activities: A Comparison of Transactional Distance Theory and Activity Theory

    Science.gov (United States)

    Kang, Haijun; Gyorke, Allan S.

    2008-01-01

    Despite its invaluable guidance to distance education development, transactional distance (TD) theory is not seamlessly synchronised with current field practice and lacks a social component. After it has provided over 30 years of guidance, there is now a need to re-appraise TD's propositions about distance learning activities. The social-cultural…

  6. The Cost of Distance Education. IEC Broadsheets on Distance Learning No. 17.

    Science.gov (United States)

    Perraton, Hilary

    One of a series offering practical advice and information on distance teaching, this broadsheet first looks at the reasons for trying to measure distance teaching costs and the methodological and economic difficulties involved in such measurements. Broadcasting and print costs in distance teaching are discussed, and evidence about the costs of…

  7. Secondary Education at a Distance. IEC Broadsheets on Distance Learning No. 12.

    Science.gov (United States)

    Perraton, Hilary

    One of a series offering practical advice and information on distance teaching, this broadsheet focuses on the ways in which distance teaching can support, expand, and change secondary education. Traditional criticisms of secondary schools are examined, including their irrelevancy, inefficiency, and inequity. Issues of distance education…

  8. Horizontal Distance Travelled by a Mobile Experiencing a Quadratic Drag Force: Normalized Distance and Parametrization

    Science.gov (United States)

    Vial, Alexandre

    2007-01-01

    We investigate the problem of the horizontal distance travelled by a mobile experiencing a quadratic drag force. We show that by introducing a normalized distance, the problem can be greatly simplified. In order to parametrize this distance, we use the Pearson VII function, and we find that the optimal launch angle as a function of the initial…

  9. Secondary Education at a Distance. IEC Broadsheets on Distance Learning No. 12.

    Science.gov (United States)

    Perraton, Hilary

    One of a series offering practical advice and information on distance teaching, this broadsheet focuses on the ways in which distance teaching can support, expand, and change secondary education. Traditional criticisms of secondary schools are examined, including their irrelevancy, inefficiency, and inequity. Issues of distance education…

  10. The Cost of Distance Education. IEC Broadsheets on Distance Learning No. 17.

    Science.gov (United States)

    Perraton, Hilary

    One of a series offering practical advice and information on distance teaching, this broadsheet first looks at the reasons for trying to measure distance teaching costs and the methodological and economic difficulties involved in such measurements. Broadcasting and print costs in distance teaching are discussed, and evidence about the costs of…

  11. Has Distance Learning Become More Flexible? Reflections of a Distance Learning Student

    Science.gov (United States)

    Thomas, Theda

    2012-01-01

    This paper provides insight into the way in which distance learning had changed over the past 30 years from the perspective of the author as a distance learning student. The question is then asked as to whether current practice is reducing flexibility for distance learning students? The paper starts with a discussion of flexible learning and the…

  12. Labour Market Theories and Distance Education I: Industrialization and Distance Education.

    Science.gov (United States)

    Rumble, Greville

    1995-01-01

    Addresses industrialization and distance education and how they relate to the modernist and postmodernist models of work, Fordism, neo-Fordism and post-Fordism. Concludes that not all distance education is industrialized; traditional education is not always a craft; and Fordism does not adequately explain the development of distance education.…

  13. GLOBALIZATION, DISTANCE EDUCATION AND HEGEMONIC FUTURES

    Directory of Open Access Journals (Sweden)

    Glenn RUSSELL

    2007-10-01

    Full Text Available ABSTRACT Consideration of the place of theory in distance education suggests that existing definitions do not adequately account for economic, cultural and historical factors. The application of the notion of hegemonic valency to distance education highlights the ways in which tools, technological systems and online environments operate in predictable ways. Historically, the imperatives of market forces and social justice have displayed a tension that is continued in contemporary contexts including virtual learning environments. A characteristic of this tension can be seen in the forces and interactions associated with globalisation and technology. These forces, in association with others, have contributed to a null curriculum in which some alternatives open to distance education practitioners remain invisible. It is likely that this situation is further compounded by the difficulty of ascertaining what distance education practices are actually operating world-wide at any identifiable time. Available options for distance educators can be understood in terms of instrumental and interpersonal axes that can potentially indicate the relative consideration that can be given to these factors. This approach is suggested as one way to understand available options at a time when there has been an apparent increase in instrumental approaches to distance education at the expense of interpersonal approaches and issues of social justice. While this problem is of concern, it is more appropriate to reflect on the unintended consequences of distance education for society and identify them than it is to uncritically oppose globalisation and its adherents.

  14. Distance-based features in pattern classification

    Directory of Open Access Journals (Sweden)

    Lin Wei-Yang

    2011-01-01

    Full Text Available Abstract In data mining and pattern classification, feature extraction and representation methods are a very important step since the extracted features have a direct and significant impact on the classification accuracy. In literature, numbers of novel feature extraction and representation methods have been proposed. However, many of them only focus on specific domain problems. In this article, we introduce a novel distance-based feature extraction method for various pattern classification problems. Specifically, two distances are extracted, which are based on (1 the distance between the data and its intra-cluster center and (2 the distance between the data and its extra-cluster centers. Experiments based on ten datasets containing different numbers of classes, samples, and dimensions are examined. The experimental results using naïve Bayes, k-NN, and SVM classifiers show that concatenating the original features provided by the datasets to the distance-based features can improve classification accuracy except image-related datasets. In particular, the distance-based features are suitable for the datasets which have smaller numbers of classes, numbers of samples, and the lower dimensionality of features. Moreover, two datasets, which have similar characteristics, are further used to validate this finding. The result is consistent with the first experiment result that adding the distance-based features can improve the classification performance.

  15. Carney Complex

    Science.gov (United States)

    ... Types of Cancer > Carney Complex Request Permissions Carney Complex Approved by the Cancer.Net Editorial Board , 11/2015 What is Carney complex? Carney complex is a hereditary condition associated with: ...

  16. Metal species involved in long distance metal transport in plants

    Science.gov (United States)

    Álvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

    2014-01-01

    The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

  17. Producing Knowledge to Reduce Rhetorical Distance

    DEFF Research Database (Denmark)

    Kampf, Constance

    Producing Knowledge to Reduce Rhetorical Distance: Extending Identity and Engaging Mainstream Ideology via the Web Constance Kampf, Department of Research Knowledge Communication, Aarhus School of Business, Denmark McLuhan describes technologies as extensions -the wheel being an extension...... writers a larger public forum into which they can extend their identity. When the identity being extended represents a minority group, the web offers an opportunity for members of that group to engage mainstream ideology and work at reducing the rhetorical distance between their identity and mainstream...... the opportunity for engaging mainstream ideologies in order to reduce the rhetorical distance between minority and majority cultures....

  18. Transforming distance education curricula through distributive leadership

    Directory of Open Access Journals (Sweden)

    Mike Keppell

    2010-12-01

    Full Text Available This paper examines a core leadership strategy for transforming learning and teaching in distance education through flexible and blended learning. It focuses on a project centred on distributive leadership that involves collaboration, shared purpose, responsibility and recognition of leadership irrespective of role or position within an organisation. Distributive leadership was a core principle in facilitating the transformation of learning and teaching through a Teaching Fellowship Scheme that empowered leaders across a regional distance education university. In parallel, a design-based research project analysed the perceptions of the Teaching Fellows in relation to blended learning, time/space, peer learning, innovation and equity issues in relation to distance education.

  19. Robustness of Distance-to-Default

    DEFF Research Database (Denmark)

    Jessen, Cathrine; Lando, David

    2013-01-01

    Distance-to-default is a remarkably robust measure for ranking firms according to their risk of default. The ranking seems to work despite the fact that the Merton model from which the measure is derived produces default probabilities that are far too small when applied to real data. We use....... A notable exception is a model with stochastic volatility of assets. In this case both the ranking of firms and the estimated default probabilities using distance-to-default perform significantly worse. We therefore propose a volatility adjustment of the distance-to-default measure, that significantly...... improves the ranking of firms with stochastic volatility....

  20. Pragmatic Distance and Appropriateness of Utterance Politeness

    Institute of Scientific and Technical Information of China (English)

    吴丽丽

    2014-01-01

    The Politeness Principle proposed by Leech complements Grice ’ Cooperative Principle to a cer-tain extent in explaining the indirectness of language .However , the nature of politeness is its relativity . Determined by various factors such as social and cultural ones , the appropriateness of politeness at utter-ance level is affected by the appropriateness of the pragmatic distance between the participants .Different from the interpersonal relationships , pragmatic distance is calculated and determined in the process of communication varying with the variation of the communicative factors .Pragmatic distance is dynamic and can be maintained and altered by participants by using certain linguistic expressions to achieve the appro -priateness of politeness in communication .

  1. Clustering of Local Group distances: publication bias or correlated measurements? III. The Small Magellanic Cloud

    CERN Document Server

    de Grijs, Richard

    2015-01-01

    Aiming at providing a firm mean distance estimate to the Small Magellanic Cloud (SMC), and thus to place it within the internally consistent Local Group distance framework we recently established, we compiled the current-largest database of published distance estimates to the galaxy. Based on careful statistical analysis, we derive mean distance estimates to the SMC using eclipsing binary systems, variable stars, stellar population tracers, and star cluster properties. Their weighted mean leads to a final recommendation for the mean SMC distance of $(m-M)_0^{\\rm SMC} = 18.96 \\pm 0.02$ mag, where the uncertainty represents the formal error. Systematic effects related to lingering uncertainties in extinction corrections, our physical understanding of the stellar tracers used, and the SMC's complex geometry---including its significant line-of-sight depth, its irregular appearance which renders definition of the galaxy's center uncertain, as well as its high inclination and possibly warped disk---may contribute a...

  2. Edge Detection of PolSAR Image Based on Stochastic Distance

    OpenAIRE

    Wang, Qing; ZENG Qiming; Zhang, Haizhen; JIAO Jian

    2015-01-01

    A new edge detection methodology in PolSAR images is proposed, which is based on stochastic distance in the statistical theory and combined with complex Wishart distribution. Its main principle is inspired from the phenomenon that stochastic distance of two classes separated by an edge is closely related to the edge direction and the contrast of two classes. Simulation experiments are carried out to analyze the performance of the proposed methods. Results prove that methods have better capabi...

  3. Space-Efficient Approximation Scheme for Circular Earth Mover Distance

    DEFF Research Database (Denmark)

    Brody, Joshua Eric; Liang, Hongyu; Sun, Xiaoming

    2012-01-01

    The Earth Mover Distance (EMD) between point sets A and B is the minimum cost of a bipartite matching between A and B. EMD is an important measure for estimating similarities between objects with quantifiable features and has important applications in several areas including computer vision....... The streaming complexity of approximating EMD between point sets in a two-dimensional discretized grid is an important open problem proposed in [8,9]. We study the problem of approximating EMD in the streaming model, when points lie on a discretized circle. Computing the EMD in this setting has applications...

  4. Environmental Impact of Long Distance Travel

    DEFF Research Database (Denmark)

    Christensen, Linda

    2016-01-01

    This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel and the cl......This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel...... and the climate burden from long overseas distances is especially high even though only few travel overseas. The travel activity is furthermore increasing much more for long distances than for European destinations. Domestic travel activity with overnight stay is nearly stagnating. The study furthermore shows...

  5. Long distance travel ‘today’

    DEFF Research Database (Denmark)

    Christensen, Linda

    2014-01-01

    This paper presents an overview of the Dane’s long distance travel. It is a part of the Drivers and Limits project about long distance travel. Long distance travel is in the project defined as infrequent travel with overnight stay. Danes 15-85 years-old travel in average 5.5 long distance travel...... per year og which a third is for international destinations, a third is for domestic second homes and a third are other domestic trips. However, 87% of the kilometres are for international destinations and only 4% are for domestic second homes. Travel activity is very uneven distributed with only half...... of the population having had a journey during the last three month. At the other hand 60% have travelled internationally during the last year and only 2% have never travelled abroad. The paper presents among other things how the travel activity is distributed on travel purpose and mode and how the mode choice...

  6. Producing Knowledge to Reduce Rhetorical Distance

    DEFF Research Database (Denmark)

    Kampf, Constance

    Producing Knowledge to Reduce Rhetorical Distance: Extending Identity and Engaging Mainstream Ideology via the Web Constance Kampf, Department of Research Knowledge Communication, Aarhus School of Business, Denmark McLuhan describes technologies as extensions -the wheel being an extension...

  7. LEVEL SET METHODS BASED ON DISTANCE FUNCTION

    Institute of Scientific and Technical Information of China (English)

    王德军; 唐云; 于洪川; 唐泽圣

    2003-01-01

    Some basic problems on the level set methods were discussed, such as the method used to preserve the distance function, the existence and uniqueness of solution for the level set equations. The main contribution is to prove that in a neighborhood of the initial zero level set, the level set equations with the restriction of the distance function have a unique solution, which must be the signed distance function with respect to the evolving surface. Some skillful approaches were used: Noticing that any solution for the original equation was a distance function, the original level set equations were transformed into a simpler alternative form. Moreover, since the new system was not a classical one, the system was transforned into an ordinary one, for which the implicit function method was adopted.

  8. Institutional Distance and the Internationalization Process

    DEFF Research Database (Denmark)

    Pogrebnyakov, Nicolai; Maitland, Carleen

    2011-01-01

    This paper applies the institutional lens to the internationalization process model. It updates the concept of psychic distance in the model with a recently developed, theoretically grounded construct of institutional distance. Institutions are considered simultaneously at the national and industry...... levels. It also aims to understand whether the internationalization process of service firms is different from the behavior predicted by the model, which was developed for the manufacturing context. We empirically test the model using proportional hazard analysis with 130 instances of entry and presence...... of mobile operators in Europe and South America over 13 years. Influences of regulative, normative and cognitive institutional aspects were disaggregated and shown to have differing effect on internationalization. This suggests that institutional distance is a viable alternative to other distance measures...

  9. Convergence of Distance Education and Conventional Learning ...

    African Journals Online (AJOL)

    Convergence of Distance Education and Conventional Learning: Innovations ... using various blended learning media including print, ICTs, electronic platforms, ... Admittedly, the blending of offline and online learning enhances significantly ...

  10. Project Work in Networked Distance Education

    DEFF Research Database (Denmark)

    Knudsen, Morten; Helbo, Jan; Jensen, Lars Peter

    2000-01-01

    . As the experience since then has proven this to be a very successful innovation in higher education [1], it seems to be an obvious idea also to base our new distance educations on the project study form. Traditionally, however, distance education has been characterized by one-way communication and self......-study, whereas the project study form is based on collaboration and dialogue. Consequently, successful implementation of project work in distance education requires extensive utilisation of new information and communication technology. In this paper the experiences of project work in a new Master of Industrial...... Information Technology distance education is described. The program is offered through Open University, and the students have a BSc degree or equivalent and at least 2 years of relevant professional experience - and a full-time job. The students are assumed to study 20 hours per week, half of the time being...

  11. Mahalanobis Distance Based Iterative Closest Point

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Blas, Morten Rufus; Larsen, Rasmus

    2007-01-01

    the notion of a mahalanobis distance map upon a point set with associated covariance matrices which in addition to providing correlation weighted distance implicitly provides a method for assigning correspondence during alignment. This distance map provides an easy formulation of the ICP problem that permits......This paper proposes an extension to the standard iterative closest point method (ICP). In contrast to ICP, our approach (ICP-M) uses the Mahalanobis distance to align a set of shapes thus assigning an anisotropic independent Gaussian noise to each point in the reference shape. The paper introduces...... a fast optimization. Initially, the covariance matrices are set to the identity matrix, and all shapes are aligned to a randomly selected shape (equivalent to standard ICP). From this point the algorithm iterates between the steps: (a) obtain mean shape and new estimates of the covariance matrices from...

  12. A glocal distance for network comparison

    CERN Document Server

    Jurman, Giuseppe; Riccadonna, Samantha; Filosi, Michele; Furlanello, Cesare

    2012-01-01

    When comparing networks (with the same number of nodes) with direct methods, a number of possible distances is already available in literature. Among others, two of the most common families are the set of edit-like distances and the spectral distances. The functions in the former family quantitatively evaluate the differences between two networks in terms of minimum number of edit operations (with possibly different costs) transforming one network into the other, that is, deletion and insertion of links, while spectral measures relies on functions of the eigenvalues of one of the connectivity matrices of the underlying graph. A noticeable issue affecting edit distance is the fact of being local, i.e. not taking into account the global structure of the networks but only summing the contributions coming from each single link. On the other hand, spectral measures cannot distinguish isomorphic or isospectral graphs. We propose here a possible solution to overcome both issues: combining together an edit and a spec...

  13. Manifold Learning by Preserving Distance Orders.

    Science.gov (United States)

    Ataer-Cansizoglu, Esra; Akcakaya, Murat; Orhan, Umut; Erdogmus, Deniz

    2014-03-01

    Nonlinear dimensionality reduction is essential for the analysis and the interpretation of high dimensional data sets. In this manuscript, we propose a distance order preserving manifold learning algorithm that extends the basic mean-squared error cost function used mainly in multidimensional scaling (MDS)-based methods. We develop a constrained optimization problem by assuming explicit constraints on the order of distances in the low-dimensional space. In this optimization problem, as a generalization of MDS, instead of forcing a linear relationship between the distances in the high-dimensional original and low-dimensional projection space, we learn a non-decreasing relation approximated by radial basis functions. We compare the proposed method with existing manifold learning algorithms using synthetic datasets based on the commonly used residual variance and proposed percentage of violated distance orders metrics. We also perform experiments on a retinal image dataset used in Retinopathy of Prematurity (ROP) diagnosis.

  14. EXAMINING POLICY GUIDELINES FOR DISTANCE EDUCATION IN ...

    African Journals Online (AJOL)

    User

    The study reports a case of distance education policy in the Kwame Nkrumah University of Sci- ... used to obtain information from 21 purposively selected key informants in the University. Policy ... practice must contain values among which is.

  15. Professional development of distance education professionals ...

    African Journals Online (AJOL)

    Erna Kinsey

    profile of functions of ETD practitioners at distance education institutions. Firstly, the .... and studied to gain a clear understanding of existing practices at. TSA. ..... (NB: Assessment has been cited as an important function in the literature, but ...

  16. Distance learning techniques for medical informatics

    Science.gov (United States)

    Hersh, W

    2000-01-01

    A growing number of health care professionals (e.g., physicians, nurses, librarians, and administrators) desire to enhance their skills and knowledge in medical informatics. These individuals are usually in established careers with limited time as well as inability to relocate to one of the small number of health science universities which offer informatics training. As a result of inquiries about distance learning in medical informatics and a market survey which documented and detailed such interest, a distance learning program was launched by the medical informatics program at Oregon Health Sciences University (OHSU). In the 1999-2000 academic year, two graduate-level medical informatics courses in the OHSU program have been taught by distance learning. In the 2000-2001 academic year, an eight-course certificate program will be launched. Further information can be found at: http://www. ohsu.edu/bicc-informatics/distance/ PMID:11080024

  17. Distance function selection in several clustering algorithrms

    Institute of Scientific and Technical Information of China (English)

    LU Yu

    2004-01-01

    Most clustering algorithms need to describe the similarity of objects by a predefined distance function. Three distance functions which are widely used in two traditional clustering algorithms k-means and hierarchical clustering were investigated.Both theoretical analysis and detailed experimental results were given. It is shown that a distance function greatly affects clustering results and can be used to detect the outlier of a cluster by the comparison of such different results and give the shape information of clusters. In practice situation, it is suggested to use different distance function separately, compare the clustering results and pick out the "swing points". And such points may leak out more information for data analysts.

  18. Improving Pulsar Distances by Modelling Interstellar Scattering

    CERN Document Server

    Deshpande, A A

    1998-01-01

    We present here a method to study the distribution of electron density fluctuations in pulsar directions as well as to estimate pulsar distances. The method, based on a simple two-component model of the scattering medium discussed by Gwinn et al. (1993), uses scintillation & proper motion data in addition to the measurements of angular broadening & temporal broadening to solve for the model parameters, namely, the fractional distance to a discrete scatterer and the ascociated relative scattering strength. We show how this method can be used to estimate pulsar distances reliably, when the location of a discrete scatterer (e.g. an HII region), if any, is known. Considering the specific example of PSR B0736-40, we illustrate how a simple characterization of the Gum nebula region (using the data on the Vela pulsar) is possible and can be used along with the temporal broadening measurements to estimate pulsar distances.

  19. Spatial interpolation of fine particulate matter concentrations using the shortest wind-field path distance.

    Directory of Open Access Journals (Sweden)

    Longxiang Li

    Full Text Available Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.

  20. The anatomical distance of functional connections predicts brain network topology in health and schizophrenia.

    Science.gov (United States)

    Alexander-Bloch, Aaron F; Vértes, Petra E; Stidd, Reva; Lalonde, François; Clasen, Liv; Rapoport, Judith; Giedd, Jay; Bullmore, Edward T; Gogtay, Nitin

    2013-01-01

    The human brain is a topologically complex network embedded in anatomical space. Here, we systematically explored relationships between functional connectivity, complex network topology, and anatomical (Euclidean) distance between connected brain regions, in the resting-state functional magnetic resonance imaging brain networks of 20 healthy volunteers and 19 patients with childhood-onset schizophrenia (COS). Normal between-subject differences in average distance of connected edges in brain graphs were strongly associated with variation in topological properties of functional networks. In addition, a club or subset of connector hubs was identified, in lateral temporal, parietal, dorsal prefrontal, and medial prefrontal/cingulate cortical regions. In COS, there was reduced strength of functional connectivity over short distances especially, and therefore, global mean connection distance of thresholded graphs was significantly greater than normal. As predicted from relationships between spatial and topological properties of normal networks, this disorder-related proportional increase in connection distance was associated with reduced clustering and modularity and increased global efficiency of COS networks. Between-group differences in connection distance were localized specifically to connector hubs of multimodal association cortex. In relation to the neurodevelopmental pathogenesis of schizophrenia, we argue that the data are consistent with the interpretation that spatial and topological disturbances of functional network organization could arise from excessive "pruning" of short-distance functional connections in schizophrenia.

  1. Spatial interpolation of fine particulate matter concentrations using the shortest wind-field path distance.

    Science.gov (United States)

    Li, Longxiang; Gong, Jianhua; Zhou, Jieping

    2014-01-01

    Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW) with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.

  2. Perspectives on Group Work In Distance Learning

    OpenAIRE

    Hausstätter, Rune Sarromaa; NORDKVELLE, Yngve Troye

    2015-01-01

    Current distance education benefits greatly from educational software that makes group work possible for students who are separated in time and space. However, some students prefer distance education because they can work on their own. This paper explores how students react to expectations on behalf of the course provider to do their assignments in collaborative groups. They are seemingly both positively surprised by the challenges that group work offer, and they are less positive to the down...

  3. Unit distances and diameters in Euclidean spaces

    CERN Document Server

    Swanepoel, Konrad J

    2007-01-01

    We show that the maximum number of unit distances or of diameters in a set of n points in d-dimensional Euclidean space is attained only by specific types of Lenz constructions, for all d >= 4 and n sufficiently large, depending on d. As a corollary we determine the exact maximum number of unit distances for all even d >= 6, and the exact maximum number of diameters for all d >= 4, for all $n$ sufficiently large, depending on d.

  4. On the inversion-indel distance.

    Science.gov (United States)

    Willing, Eyla; Zaccaria, Simone; Braga, Marília D V; Stoye, Jens

    2013-01-01

    The inversion distance, that is the distance between two unichromosomal genomes with the same content allowing only inversions of DNA segments, can be computed thanks to a pioneering approach of Hannenhalli and Pevzner in 1995. In 2000, El-Mabrouk extended the inversion model to allow the comparison of unichromosomal genomes with unequal contents, thus insertions and deletions of DNA segments besides inversions. However, an exact algorithm was presented only for the case in which we have insertions alone and no deletion (or vice versa), while a heuristic was provided for the symmetric case, that allows both insertions and deletions and is called the inversion-indel distance. In 2005, Yancopoulos, Attie and Friedberg started a new branch of research by introducing the generic double cut and join (DCJ) operation, that can represent several genome rearrangements (including inversions). Among others, the DCJ model gave rise to two important results. First, it has been shown that the inversion distance can be computed in a simpler way with the help of the DCJ operation. Second, the DCJ operation originated the DCJ-indel distance, that allows the comparison of genomes with unequal contents, considering DCJ, insertions and deletions, and can be computed in linear time. In the present work we put these two results together to solve an open problem, showing that, when the graph that represents the relation between the two compared genomes has no bad components, the inversion-indel distance is equal to the DCJ-indel distance. We also give a lower and an upper bound for the inversion-indel distance in the presence of bad components.

  5. Redshift-distance relation in inhomogeneous cosmology

    CERN Document Server

    Scharf, Günter

    2015-01-01

    We continue to study a cosmological model with large-scale inhomogeneity. Working in the cosmic rest frame we determine null geodesics, redshift and area and luminosity distance. Combining the result with Hubble's law enables us to calculate the distance of the local group of galaxies from the origin where the Big Bang gas taken place. We obtain a surprisingly small value of about 2 million light years.

  6. Auditory Perception in Open Field: Distance Estimation

    Science.gov (United States)

    2013-07-01

    the distance and spaciousness estimation cues can be ambiguous (e.g., sound intensity, sound spectrum) or are fairly weak (e.g., binaural cues...Invariance in Sound Perception. Acta Psychologica Fennica 1951, 1, 9–20. Florentine, M.; Epstein, M. Ecological Loudness. Binaural Loudness Constancy...8, 145–149. 50 Lu, Y-Ch.; Cooke, M. Binaural Estimation of Sound Source Distance via the Direct-to- Reverberant Energy Ratio for Static and Moving

  7. Markets, Distance Education, and Australian Higher Education

    OpenAIRE

    2005-01-01

    The paper argues that the Australian university system is unstable. There will be significant change as government implements its reform agenda and even more radical change if it moves to new deregulation. The role of distance education in university education needs to be analyzed against this ‘market’ agenda of government in terms of characteristics of markets and market behavior. After a scan of the current role, the paper looks at two scenarios (regulated and deregulated) for distance educ...

  8. Designing legible fonts for distance reading

    DEFF Research Database (Denmark)

    Beier, Sofie

    2016-01-01

    This chapter reviews existing knowledge on distance legibility of fonts, and finds that for optimal distance reading, letters and numbers benefit from relative wide shapes, open inner counters and a large x-height; fonts should further be widely spaced, and the weight should not be too heavy or too...... light. Research also indicates that serifs on the vertical extremes improve legibility under such reading conditions....

  9. 6-DoF Haptic Rendering Using Continuous Collision Detection between Points and Signed Distance Fields.

    Science.gov (United States)

    Hongyi Xu; Barbic, Jernej

    2017-01-01

    We present an algorithm for fast continuous collision detection between points and signed distance fields, and demonstrate how to robustly use it for 6-DoF haptic rendering of contact between objects with complex geometry. Continuous collision detection is often needed in computer animation, haptics, and virtual reality applications, but has so far only been investigated for polygon (triangular) geometry representations. We demonstrate how to robustly and continuously detect intersections between points and level sets of the signed distance field. We suggest using an octree subdivision of the distance field for fast traversal of distance field cells. We also give a method to resolve continuous collisions between point clouds organized into a tree hierarchy and a signed distance field, enabling rendering of contact between rigid objects with complex geometry. We investigate and compare two 6-DoF haptic rendering methods now applicable to point-versus-distance field contact for the first time: continuous integration of penalty forces, and a constraint-based method. An experimental comparison to discrete collision detection demonstrates that the continuous method is more robust and can correctly resolve collisions even under high velocities and during complex contact.

  10. Radial Distance Estimation with Tapered Whisker Sensors.

    Science.gov (United States)

    Ahn, Sejoon; Kim, DaeEun

    2017-07-19

    Rats use their whiskers as tactile sensors to sense their environment. Active whisking, moving whiskers back and forth continuously, is one of prominent features observed in rodents. They can discriminate different textures or extract features of a nearby object such as size, shape and distance through active whisking. There have been studies to localize objects with artificial whiskers inspired by rat whiskers. The linear whisker model based on beam theory has been used to estimate the radial distance, that is, the distance between the base of the whisker and a target object. In this paper, we investigate deflection angle measurements instead of forces or moments, based on a linear tapered whisker model to see the role of tapered whiskers found in real animals. We analyze how accurately this model estimates the radial distance, and quantify the estimation errors and noise sensitivity. We also compare the linear model simulation and nonlinear numerical solutions. It is shown that the radial distance can be estimated using deflection angles at two different positions on the tapered whisker. We argue that the tapered whisker has an advantage of estimating the radial distance better, as compared to an untapered whisker, and active sensing allows that estimation without the whisker's material property and thickness or the moment at base. In addition, we investigate the potential of passive sensing for tactile localization.

  11. On distance variation effects on graphene bilayers

    Science.gov (United States)

    Naji, S.; Bhihi, M.; Labrim, H.; Belhaj, A.; Benyoussef, A.; El Kenz, A.; Loulidi, M.

    2014-06-01

    The opening of the energy gap and the total energy of the graphene-like bilayers are investigated using ab initio calculations. The studied model consists of a static single layer of graphene interacting with an extra dynamic one placed at a varying vertical distance d in the (AB) stacking arrangement. The effects of the vertical distance variation on the energy gap and the total energy of the system are discussed first. Starting from a distance around the van der Waals length, the energy gap does not depend on the vertical distance variation and the system exhibits graphene-like properties with minor deformations in the lattice size parameter and the energy dispersion behaviour around K points. However, it has been shown that the diagonal distance variation of the graphene-like bilayer modifies the electronic structure properties. This modification depends on an intermediate stacking arrangement between the (AA) and the (AB) configurations. It has been shown that the diagonal distance variation has an influence on the states of pz electrons in the (AB) arrangement and it can be explored to open the energy gap.

  12. Distance determination from dysprosium induced relaxation enhancement: a case study on membrane-inserted WALP23 polypeptides

    NARCIS (Netherlands)

    Lueders, P.; Razzaghi, S.; Jäger, H.; Tschaggelar, R.; Hemminga, M.A.; Yulikov, M.; Jeschke, G.

    2013-01-01

    Membrane incorporated synthetic a-helical polypeptides labelled with Dy(III) chelate complexes and nitroxide radicals were studied by the inversion recovery (IR) technique and Dy(III)-nitroxide distances were obtained. A comparison of obtained distances with the previously reported Gd(III)-nitroxide

  13. Complex Beauty

    OpenAIRE

    Franceschet, Massimo

    2014-01-01

    Complex systems and their underlying convoluted networks are ubiquitous, all we need is an eye for them. They pose problems of organized complexity which cannot be approached with a reductionist method. Complexity science and its emergent sister network science both come to grips with the inherent complexity of complex systems with an holistic strategy. The relevance of complexity, however, transcends the sciences. Complex systems and networks are the focal point of a philosophical, cultural ...

  14. Extraction of distance restraints from pure shift NOE experiments

    Science.gov (United States)

    Kaltschnee, Lukas; Knoll, Kevin; Schmidts, Volker; Adams, Ralph W.; Nilsson, Mathias; Morris, Gareth A.; Thiele, Christina M.

    2016-10-01

    NMR techniques incorporating pure shift methods to improve signal resolution have recently attracted much attention, owing to their potential use in studies of increasingly complex molecular systems. Extraction of frequencies from these simplified spectra enables easier structure determination, but only a few of the methods presented provide structural parameters derived from signal integral measurements. In particular, for quantification of the nuclear Overhauser effect (NOE) it is highly desirable to utilize pure shift techniques where signal overlap normally prevents accurate signal integration, to enable measurement of a larger number of interatomic distances. However, robust methods for the measurement of interatomic distances using the recently developed pure shift techniques have not been reported to date. In this work we discuss some of the factors determining the accuracy of measurements of signal integrals in interferogram-based Zangger-Sterk (ZS) pure shift NMR experiments. The ZS broadband homodecoupling technique is used in different experiments designed for quantitative NOE determination from pure shift spectra. It is shown that the techniques studied can be used for quantitative extraction of NOE-derived distance restraints, as exemplified for the test case of strychnine.

  15. Locality-Sensitive Hashing for Chi2 distance.

    Science.gov (United States)

    Gorisse, David; Cord, Matthieu; Precioso, Frederic

    2012-02-01

    In the past 10 years, new powerful algorithms based on efficient data structures have been proposed to solve the problem of Nearest Neighbors search (or Approximate Nearest Neighbors search). If the Euclidean Locality Sensitive Hashing algorithm, which provides approximate nearest neighbors in a euclidean space with sublinear complexity, is probably the most popular, the euclidean metric does not always provide as accurate and as relevant results when considering similarity measure as the Earth-Mover Distance and 2 distances. In this paper, we present a new LSH scheme adapted to 2 distance for approximate nearest neighbors search in high-dimensional spaces. We define the specific hashing functions, we prove their local-sensitivity, and compare, through experiments, our method with the Euclidean Locality Sensitive Hashing algorithm in the context of image retrieval on real image databases. The results prove the relevance of such a new LSH scheme either providing far better accuracy in the context of image retrieval than euclidean scheme for an equivalent speed, or providing an equivalent accuracy but with a high gain in terms of processing speed.

  16. TRENDS TOWARDS DISTANCE EDUCATION OF NURSING EDUCATION IN TURKEY

    Directory of Open Access Journals (Sweden)

    Emine SENYUVA

    2011-10-01

    Full Text Available The contemporary world, developments, changes, transformations, globalization, information and communication technologies developments, diversification of the educational environment and life-long education to become compulsory in education, learning-teaching process efficiency and effectiveness in their discussion raises, while the educational technology, the concept was put forward. With the concept of educational technology and communication technologies bigi be used effectively in the field of education has become compulsory. Next to this case, the individual's formal education at any time and anywhere access to educational programs that allow participation distance education has led to the need to. In today’s world rapidly changing, evolving and increasingly complex area of a state health care services, nursing education from the issuing institution, advanced human and professional members of the advanced characteristics and has adopted the lifelong development of nurses are required to have graduated. Resources in this direction was examined, the distance education of nurses after graduation various vocational courses, certificate programs until completion and graduate degree (master and PhD education in maintaining the successful results to indicate. Therefore, distance education, nursing education to university level upgrade accelerated nursing education experienced in the quality-quantity to the solution of the problem, the continuity of nursing education and contribute to the professional will provide a large group of educational opportunities will be taken into consideration must be considered and appropriate studies, arrangements should be made.

  17. Distance Education in Information Technology, a case study

    DEFF Research Database (Denmark)

    Helbo, Jan; Knudsen, Morten

    2002-01-01

    Project organized problem based learning is a successful concept for on-campus education at Aalborg University. The "Aalborg concept" has been used in networked distance education as well. This paper describes a project from the first year of our Master of Information Technology education organiz...... of project in group-organized distance education, are described and commented by three of the group members, and some possible solutions for more appropriate types of projects are listed......Project organized problem based learning is a successful concept for on-campus education at Aalborg University. The "Aalborg concept" has been used in networked distance education as well. This paper describes a project from the first year of our Master of Information Technology education organized...... with Internet-mediated project work. A group of 4 students carried out a project dependent on knowledge from two firms where two of the group members are working, making this a kind of Worked Based Learning (WBL). The project was formulated as a traditional on-campus type of project with the same complexity...

  18. TCP-Adaptive in High Speed Long Distance Networks

    Directory of Open Access Journals (Sweden)

    Quan Liu

    2014-02-01

    Full Text Available With the development of high performance computing and increasing of network bandwidth, more and more applications require fast data transfer over high-speed long-distance networks. Research shows that the standard TCP Reno cannot fulfill the requirement of fast transfer of massive data due to its conservative congestion control mechanism. Some works have been proposed to improve the TCP throughput performance using more aggressive window increasing tactics and obtain substantial achievements. However, they cannot be strictly proved to be comprehensively suitable for high-speed complex network environments. In this paper, we propose TCP-Adaptive, an adaptive congestion control algorithm adjusting the increasing congestion window dynamically. The algorithm improves logarithmic detection procedure for available bandwidth in the flow path by distinguishing the first detection in congestion avoidance and retransmission timeout. On the other hand, an adaptive control algorithm is proposed to achieve better performance in high-speed long-distance networks. The algorithm uses round trip time (RTT variations to predict the congestion trends to update the increments of congestion window. Simulations verify the property of TCP-Adaptive and show satisfying performance in throughput, RTT fairness aspects over high-speed long-distance networks. Especially in sporadic loss environment, TCP-Adaptive shows a significant adaptability with the variations of link quality

  19. Identifying multiple influential spreaders in term of the distance-based coloring

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Lei; Lin, Jian-Hong; Guo, Qiang [Research Center of Complex Systems Science, University of Shanghai for Science and Technology, Shanghai 200093 (China); Liu, Jian-Guo, E-mail: liujg004@ustc.edu.cn [Research Center of Complex Systems Science, University of Shanghai for Science and Technology, Shanghai 200093 (China); Data Science and Cloud Service Research Centre, Shanghai University of Finance and Economics, Shanghai 200433 (China)

    2016-02-22

    Identifying influential nodes is of significance for understanding the dynamics of information diffusion process in complex networks. In this paper, we present an improved distance-based coloring method to identify the multiple influential spreaders. In our method, each node is colored by a kind of color with the rule that the distance between initial nodes is close to the average distance of a network. When all nodes are colored, nodes with the same color are sorted into an independent set. Then we choose the nodes at the top positions of the ranking list according to their centralities. The experimental results for an artificial network and three empirical networks show that, comparing with the performance of traditional coloring method, the improvement ratio of our distance-based coloring method could reach 12.82%, 8.16%, 4.45%, 2.93% for the ER, Erdős, Polblogs and Routers networks respectively. - Highlights: • We present an improved distance-based coloring method to identify the multiple influential spreaders. • Each node is colored by a kind of color where the distance between initial nodes is close to the average distance. • For three empirical networks show that the improvement ratio of our distance-based coloring method could reach 8.16% for the Erdos network.

  20. Spatial interpolation of river channel topography using the shortest temporal distance

    Science.gov (United States)

    Zhang, Yanjun; Xian, Cuiling; Chen, Huajin; Grieneisen, Michael L.; Liu, Jiaming; Zhang, Minghua

    2016-11-01

    It is difficult to interpolate river channel topography due to complex anisotropy. As the anisotropy is often caused by river flow, especially the hydrodynamic and transport mechanisms, it is reasonable to incorporate flow velocity into topography interpolator for decreasing the effect of anisotropy. In this study, two new distance metrics defined as the time taken by water flow to travel between two locations are developed, and replace the spatial distance metric or Euclidean distance that is currently used to interpolate topography. One is a shortest temporal distance (STD) metric. The temporal distance (TD) of a path between two nodes is calculated by spatial distance divided by the tangent component of flow velocity along the path, and the STD is searched using the Dijkstra algorithm in all possible paths between two nodes. The other is a modified shortest temporal distance (MSTD) metric in which both the tangent and normal components of flow velocity were combined. They are used to construct the methods for the interpolation of river channel topography. The proposed methods are used to generate the topography of Wuhan Section of Changjiang River and compared with Universal Kriging (UK) and Inverse Distance Weighting (IDW). The results clearly showed that the STD and MSTD based on flow velocity were reliable spatial interpolators. The MSTD, followed by the STD, presents improvement in prediction accuracy relative to both UK and IDW.

  1. Thickness and clearance visualization based on distance field of 3D objects

    Directory of Open Access Journals (Sweden)

    Masatomo Inui

    2015-07-01

    Full Text Available This paper proposes a novel method for visualizing the thickness and clearance of 3D objects in a polyhedral representation. The proposed method uses the distance field of the objects in the visualization. A parallel algorithm is developed for constructing the distance field of polyhedral objects using the GPU. The distance between a voxel and the surface polygons of the model is computed many times in the distance field construction. Similar sets of polygons are usually selected as close polygons for close voxels. By using this spatial coherence, a parallel algorithm is designed to compute the distances between a cluster of close voxels and the polygons selected by the culling operation so that the fast shared memory mechanism of the GPU can be fully utilized. The thickness/clearance of the objects is visualized by distributing points on the visible surfaces of the objects and painting them with a unique color corresponding to the thickness/clearance values at those points. A modified ray casting method is developed for computing the thickness/clearance using the distance field of the objects. A system based on these algorithms can compute the distance field of complex objects within a few minutes for most cases. After the distance field construction, thickness/clearance visualization at a near interactive rate is achieved.

  2. A Fast Generalized Minimum Distance Decoder for Reed-Solomon Codes Based on the Extended Euclidean Algorithm

    CERN Document Server

    Kampf, Sabine

    2010-01-01

    This paper presents a method to determine a set of basis polynomials from the extended Euclidean algorithm that allows Generalized Minimum Distance decoding of Reed-Solomon codes with a complexity of O(nd).

  3. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    neutrons, liberating a little energy and creating complexity. Then, the expanding universe cooled some more, and neutrons and protons, no longer kept apart by immense temperatures, found themselves unstable and formed helium nuclei. Then, a little more cooling, and atomic nuclei and electrons were no longer kept apart, and the universe became transparent. Then a little more cooling, and the next instability began: gravitation pulled matter together across cosmic distances to form stars and galaxies. This instability is described as a "negative heat capadty" in which extracting energy from a gravitating system makes it hotter -- clearly the 2nd law of thermodynamics does not apply here! (This is the physicist's part of the answer to e e cummings' question: what is the wonder that's keeping the stars apart?) Then, the next instability is that hydrogen and helium nuclei can fuse together to release energy and make stars burn for billions of years. And then at the end of the fuel source, stars become unstable and explode and liberate the chemical elements back into space. And because of that, on planets like Earth, sustained energy flows support the development of additional instabilities and all kinds of complex patterns. Gravitational instability pulls the densest materials into the core of the Earth, leaving a thin skin of water and air, and makes the interior churn incessantly as heat flows outwards. And the heat from the sun, received mostly near the equator and flowing towards the poles, supports the complex atmospheric and oceanic circulations. And because or that, the physical Earth is full of natural chemical laboratories, concentrating elements here, mixing them there, raising and lowering temperatures, ceaselessly experimenting with uncountable events where new instabilities can arise. At least one of them was the new experiment called life. Now that we know that there are at least as many planets as there are stars, it is hard to imagine that nature's ceasess

  4. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    neutrons, liberating a little energy and creating complexity. Then, the expanding universe cooled some more, and neutrons and protons, no longer kept apart by immense temperatures, found themselves unstable and formed helium nuclei. Then, a little more cooling, and atomic nuclei and electrons were no longer kept apart, and the universe became transparent. Then a little more cooling, and the next instability began: gravitation pulled matter together across cosmic distances to form stars and galaxies. This instability is described as a "negative heat capadty" in which extracting energy from a gravitating system makes it hotter -- clearly the 2nd law of thermodynamics does not apply here! (This is the physicist's part of the answer to e e cummings' question: what is the wonder that's keeping the stars apart?) Then, the next instability is that hydrogen and helium nuclei can fuse together to release energy and make stars burn for billions of years. And then at the end of the fuel source, stars become unstable and explode and liberate the chemical elements back into space. And because of that, on planets like Earth, sustained energy flows support the development of additional instabilities and all kinds of complex patterns. Gravitational instability pulls the densest materials into the core of the Earth, leaving a thin skin of water and air, and makes the interior churn incessantly as heat flows outwards. And the heat from the sun, received mostly near the equator and flowing towards the poles, supports the complex atmospheric and oceanic circulations. And because or that, the physical Earth is full of natural chemical laboratories, concentrating elements here, mixing them there, raising and lowering temperatures, ceaselessly experimenting with uncountable events where new instabilities can arise. At least one of them was the new experiment called life. Now that we know that there are at least as many planets as there are stars, it is hard to imagine that nature's ceasess

  5. Averaging of random sets based on their distance functions

    NARCIS (Netherlands)

    Baddeley, A.J.; Molchanov, I.S.

    1995-01-01

    A new notion of expectation (or distance average) of random closed sets based on their distance function representation is introduced. A general concept of the distance function is exploited to define the expectation, which is the set whose distance function is closest to the expected distance funct

  6. A Foundation for Efficient Indoor Distance-Aware Query Processing

    DEFF Research Database (Denmark)

    Lu, Hua; Cao, Xin; Jensen, Christian Søndergaard

    2012-01-01

    indoor distances. However, existing indoor space models do not account well for indoor distances. To address this shortcoming, we propose a data management infrastructure that captures indoor distance and facilitates distance-aware query processing. In particular, we propose a distance-aware indoor space...

  7. 14 CFR 25.113 - Takeoff distance and takeoff run.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Takeoff distance and takeoff run. 25.113... and takeoff run. (a) Takeoff distance on a dry runway is the greater of— (1) The horizontal distance... include a clearway, the takeoff run is equal to the takeoff distance. If the takeoff distance includes...

  8. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  9. Estimating Distances from Parallaxes. III. Distances of Two Million Stars in the Gaia DR1 Catalogue

    Science.gov (United States)

    Astraatmadja, Tri L.; Bailer-Jones, Coryn A. L.

    2016-12-01

    We infer distances and their asymmetric uncertainties for two million stars using the parallaxes published in the Gaia DR1 (GDR1) catalogue. We do this with two distance priors: A minimalist, isotropic prior assuming an exponentially decreasing space density with increasing distance, and an anisotropic prior derived from the observability of stars in a Milky Way model. We validate our results by comparing our distance estimates for 105 Cepheids which have more precise, independently estimated distances. For this sample we find that the Milky Way prior performs better (the rms of the scaled residuals is 0.40) than the exponentially decreasing space density prior (rms is 0.57), although for distances beyond 2 kpc the Milky Way prior performs worse, with a bias in the scaled residuals of -0.36 (versus -0.07 for the exponentially decreasing space density prior). We do not attempt to include the photometric data in GDR1 due to the lack of reliable color information. Our distance catalog is available at http://www.mpia.de/homes/calj/tgas_distances/main.html as well as at CDS. This should only be used to give individual distances. Combining data or testing models should be done with the original parallaxes, and attention paid to correlated and systematic uncertainties.

  10. Constraining the Correlation Distance in Quantum Measurements

    CERN Document Server

    Schneider, Jean

    2010-01-01

    Standard Quantum Physics states that the outcome of measurements for some distant entangled subsystems are instantaneously statistically correlated, whatever their mutual distance. This correlation presents itself as if there were a correlation at a distance with infinite speed. It is expressed by the Bell Theorem. It has been experimentally verified over distances up to 18 km with a time resolution of a few picosecond, which can be translated into an apparent effective correlation speed larger than 10^7 c. The purpose of the present White Paper is to discuss the scientific interest and the feasibility to extend the correlation distance up to the Earth-Moon distance, i.e. 2 10^4 times larger than in present experiments. We are thus led to propose to install on the Moon a polarimter and a high performance photon detector with a high temporal resolution. Such an exploratory experiment would provide new tests of Quantum Physics and could perhaps discriminate between standard Quantum Physics and for instance the ...

  11. A Distance Measure for Genome Phylogenetic Analysis

    Science.gov (United States)

    Cao, Minh Duc; Allison, Lloyd; Dix, Trevor

    Phylogenetic analyses of species based on single genes or parts of the genomes are often inconsistent because of factors such as variable rates of evolution and horizontal gene transfer. The availability of more and more sequenced genomes allows phylogeny construction from complete genomes that is less sensitive to such inconsistency. For such long sequences, construction methods like maximum parsimony and maximum likelihood are often not possible due to their intensive computational requirement. Another class of tree construction methods, namely distance-based methods, require a measure of distances between any two genomes. Some measures such as evolutionary edit distance of gene order and gene content are computational expensive or do not perform well when the gene content of the organisms are similar. This study presents an information theoretic measure of genetic distances between genomes based on the biological compression algorithm expert model. We demonstrate that our distance measure can be applied to reconstruct the consensus phylogenetic tree of a number of Plasmodium parasites from their genomes, the statistical bias of which would mislead conventional analysis methods. Our approach is also used to successfully construct a plausible evolutionary tree for the γ-Proteobacteria group whose genomes are known to contain many horizontally transferred genes.

  12. INVESTIGATING DISTANCE EDUCATION STUDENTS’ STUDY SKILLS

    Directory of Open Access Journals (Sweden)

    Cengiz POYRAZ

    2013-10-01

    Full Text Available Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at their pace and control their learning path, content and load of what they have learned and evaluate it. However, they should adopt strategies for effective studying in order not to waste their time and efforts. Because study skills, motivation, time management, exam preparation and coping with exam stress have an impact on students’ success. In this context, distance education students’ study skills are foregrounded in today’s widespread use of distance education. In accordance with this, this study aims to investigate some variables which are influential on the dimensions of distance education students’ motivation, time management, exam preparation and coping with exam stress. A personal information form and the Study Skills scale were used for data collection. This study was designed in survey model and SPSS16.0 statistical package program was used for the statistical analyses of the research data. The research findings were discussed in line with the literature and some suggestions were presented for further research and researchers.

  13. A NEW METHOD FOR MEASURING EXTRAGALACTIC DISTANCES

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Yuzuru; Minezaki, Takeo [Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kobayashi, Yukiyasu [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Koshida, Shintaro [Center of Astro Engineering and Department of Electrical Engineering, Pontificia Univercsidad Catolica de Chile, Av. Vicuna Mackenna 4868 (Chile); Peterson, Bruce A., E-mail: yoshii@ioa.s.u-tokyo.ac.jp [Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, Australian National University, Weston Creek P.O., ACT 2611 (Australia)

    2014-03-20

    We have pioneered a new method for the measurement of extragalactic distances. This method uses the time lag between variations in the short wavelength and long wavelength light from an active galactic nucleus (AGN), based on a quantitative physical model of dust reverberation that relates the time lag to the absolute luminosity of the AGN. We use the large homogeneous data set from intensive monitoring observations in optical and near-infrared wavelength bands with the dedicated 2 m MAGNUM telescope to obtain the distances to 17 AGNs in the redshift range z = 0.0024 to z = 0.0353. These distance measurements are compared with distances measured using Cepheid variable stars, and are used to infer that H {sub 0} = 73 ± 3 (random) km s{sup –1} Mpc{sup –1}. The systematic error in H {sub 0} is examined, and the uncertainty in the size distribution of dust grains is the largest source of the systematic error, which is much reduced for a sample of AGNs for which their parameter values in the model of dust reverberation are individually measured. This AGN time lag method can be used beyond 30 Mpc, the farthest distance reached by extragalactic Cepheids, and can be extended to high-redshift quasi-stellar objects.

  14. KINEMATIC DISTANCE ASSIGNMENTS WITH H I ABSORPTION

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Courtney; Dickey, John M. [School of Mathematics and Physics, Private Bag 37, University of Tasmania, Hobart 7000 (Australia)

    2012-07-01

    Using H I absorption spectra from the International Galactic Plane Survey, a new method is implemented to resolve the kinematic distance ambiguity for 75 H II regions with known systemic velocities from radio recombination lines. A further 40 kinematic distance determinations are made for H II region candidates without known systemic velocities through an investigation of the presence of H I absorption around the terminal velocity. New kinematic distance determinations can be used to further constrain spiral arm parameters and the location and extent of other structures in the Milky Way disk. H I absorption toward continuum sources beyond the solar circle is also investigated. Follow-up studies of H I at higher resolution than the 1' to 2' of existing Galactic Plane Surveys will provide kinematic distances to many more H II regions on the far side of the Galactic center. On the basis of the velocity channel summation technique developed in this paper, a much larger sample of H II regions will be analyzed in a future paper to remove the near-far distance ambiguity.

  15. Stochastic model updating using distance discrimination analysis

    Institute of Scientific and Technical Information of China (English)

    Deng Zhongmin; Bi Sifeng; Sez Atamturktur

    2014-01-01

    This manuscript presents a stochastic model updating method, taking both uncertainties in models and variability in testing into account. The updated finite element (FE) models obtained through the proposed technique can aid in the analysis and design of structural systems. The authors developed a stochastic model updating method integrating distance discrimination analysis (DDA) and advanced Monte Carlo (MC) technique to (1) enable more efficient MC by using a response surface model, (2) calibrate parameters with an iterative test-analysis correlation based upon DDA, and (3) utilize and compare different distance functions as correlation metrics. Using DDA, the influence of distance functions on model updating results is analyzed. The proposed sto-chastic method makes it possible to obtain a precise model updating outcome with acceptable cal-culation cost. The stochastic method is demonstrated on a helicopter case study updated using both Euclidian and Mahalanobis distance metrics. It is observed that the selected distance function influ-ences the iterative calibration process and thus, the calibration outcome, indicating that an integra-tion of different metrics might yield improved results.

  16. Validity of Self-Reported Running Distance.

    Science.gov (United States)

    Dideriksen, Mette; Soegaard, Cristina; Nielsen, Rasmus O

    2016-06-01

    It is unclear whether there is a difference between subjective evaluation and objective global positioning systems (GPS) measurement of running distance. The purpose of this study was to investigate if such difference exists. A total of 100 participants (51% men; median age, 41.5; body mass, 78.1 kg ±13.8 SD) completed a run of free choice, then subjectively reported the distance in kilometer (km). This information was subsequently compared with the distance derived from a nondifferential GPS watch using paired t-tests and Bland-Altman's 95% limits of agreement. No significant difference was found between the mean paired differences between subjective evaluations and GPS measurements (1.86%, 95% confidence interval = -1.53%; 5.25%, p = 0.96). The Bland-Altman 95% limits of agreement revealed considerable variation (lower limit = -28% and upper limit = 40%). Such variation exceeds the clinical error range of 10%. In conclusion, the mean running distance (km) is similar between self-reporting and GPS measurements. However, researchers should consider using GPS measurements in favor of subjective reporting of running distance because of considerable variation on an individual level.

  17. Distance Duality Relation from Strong Gravitational Lensing

    CERN Document Server

    Liao, Kai; Cao, Shuo; Biesiada, Marek; Zheng, Xiaogang; Zhu, Zong-Hong

    2015-01-01

    Under very general assumptions of metric theory of spacetime, photons traveling along null geodesics and photon number conservation, two observable concepts of cosmic distance, i.e. the angular diameter and the luminosity distances are related to each other by the so called distance duality relation (DDR) $D^L=D^A(1+z)^2$. Observational validation of this relation is quite important because any evidence of its violation could be a signal of new physics. In this letter we introduce a new method to test DDR based on strong gravitational lensing systems and supernovae Ia. Using a new compilation of strong lensing systems and JLA compilation of SNe Ia we found no evidence of DDR violation. However, not so much the final result but the method itself is worth attention, because unlike previously proposed techniques, it does not depend on prior assumptions concerning the details of cosmological model and galaxy cluster modelling.

  18. Optimal architectures for long distance quantum communication.

    Science.gov (United States)

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D; Jiang, Liang

    2016-02-15

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥ 1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.

  19. Length and distance on a quantum space

    CERN Document Server

    Martinetti, Pierre

    2012-01-01

    This contribution is an introduction to the metric aspect of noncommutative geometry, with emphasize on the Moyal plane. Starting by questioning "how to define a standard meter in a space whose coordinates no longer commute?", we list several recent results regarding Connes's spectral distance calculated between eigenstates of the quantum harmonic oscillator arXiv:0912.0906, as well as between coherent states arXiv:1110.6164. We also question the difference (which remains hidden in the commutative case) between the spectral distance and the notion of quantum length inherited from the length operator defined in various models of noncommutative space-time (DFR and \\theta-Minkowski). We recall that a standard procedure in noncommutative geometry, consisting in doubling the spectral triple, allows to fruitfully confront the spectral distance with the quantum length. Finally we refine the idea of discrete vs. continuous geodesics in the Moyal plane, introduced in arXiv:1106.0261.

  20. Spectral Clustering with Local Projection Distance Measurement

    Directory of Open Access Journals (Sweden)

    Chen Diao

    2015-01-01

    Full Text Available Constructing a rational affinity matrix is crucial for spectral clustering. In this paper, a novel spectral clustering via local projection distance measure (LPDM is proposed. In this method, the Local-Projection-Neighborhood (LPN is defined, which is a region between a pair of data, and other data in the LPN are projected onto the straight line among the data pairs. Utilizing the Euclidean distance between projective points, the local spatial structure of data can be well detected to measure the similarity of objects. Then the affinity matrix can be obtained by using a new similarity measurement, which can squeeze or widen the projective distance with the different spatial structure of data. Experimental results show that the LPDM algorithm can obtain desirable results with high performance on synthetic datasets, real-world datasets, and images.

  1. A note on the injection distance

    DEFF Research Database (Denmark)

    Bulygin, Stanislav; Geil, Hans Olav; Ruano Benito, Diego

    2009-01-01

    . Recently, Silva and Kschischang introduced in [D. Silva and F.R. Kschischang, "On Metrics for Error Correction in Network Coding," To appear in IEEE Trans. Inform. Theory, ArXiv: 0805.3824v4[cs.IT], 2009] the injection distance to give a detailed picture of what happens in noncoherent network coding. We......Koetter and Kschischang showed in [R. Koetter and F.R. Kschischang, "Coding for Errors and Erasures in Random Network Coding," IEEE Trans. Inform. Theory, {54(8), 2008] that the network coding counterpart of Gabidulin codes performs asymptotically optimal with respect to the subspace distance...... show that the above codes are also asymptotically optimal with respect to this distance....

  2. Distance dependence of fluorescence resonance energy transfer

    Indian Academy of Sciences (India)

    R S Swathi; K L Sebastian

    2009-09-01

    Deviations from the usual -6 dependence of the rate of fluorescence resonance energy transfer (FRET) on the distance between the donor and the acceptor have been a common scenario in the recent times. In this paper, we present a critical analysis of the distance dependence of FRET, and try to illustrate the non--6 type behaviour of the rate for the case of transfer from a localized electronic excitation on the donor, a dye molecule to three different energy acceptors with delocalized electronic excitations namely, graphene, a two-dimensional semiconducting sheet and the case of such a semiconducting sheet rolled to obtain a nanotube. We use simple analytic models to understand the distance dependence in each case.

  3. Distance-Based Opportunistic Mobile Data Offloading

    Science.gov (United States)

    Lu, Xiaofeng; Lio, Pietro; Hui, Pan

    2016-01-01

    Cellular network data traffic can be offload onto opportunistic networks. This paper proposes a Distance-based Opportunistic Publish/Subscribe (DOPS) content dissemination model, which is composed of three layers: application layer, decision-making layer and network layer. When a user wants new content, he/she subscribes on a subscribing server. Users having the contents decide whether to deliver the contents to the subscriber based on the distance information. If in the meantime a content owner has traveled further in the immediate past time than the distance between the owner and the subscriber, the content owner will send the content to the subscriber through opportunistic routing. Simulations provide an evaluation of the data traffic offloading efficiency of DOPS. PMID:27314361

  4. Scenario Crisis Cases in Distance Learning Sessions

    Science.gov (United States)

    Antunes, A.

    2013-04-01

    We discuss early results using student-lead role-play of crises and disaster scenarios to encourage engagement in distance learning sessions. The disadvantage of distance learning via web interface—the lack of face-to-face and the ease with which a student can remain quiet—is balanced by the wealth of Internet-accessible media reports of past mission disasters. Capitol College minimizes the lecture component to simply frame each session's open-ended crisis in our Mission Operations engineering course. The students are presented with a historical ‘disaster’ but not its resolution; they present their course of action, then the lecturer steps in to debrief. With a wealth of past cases available on the web, use of scenarios rather than lectures shows early signs of being viable model for encouraging discussion and interaction within distance learning for a variety of course topics.

  5. Estimating shot distance from limited pellets pattern.

    Science.gov (United States)

    Plebe, Alessio; Compagnini, Domenico

    2012-10-10

    Several methods are available for shooting range estimation based on pellets pattern on the target that have a remarkable degree of accuracy. The task is usually approached working under the assumption that the entire distribution of pellets is available for examination. These methods fail, however, when the victim has been hit by a portion of the pattern only. The problem can be solved with reasonable accuracy when there are areas of void in the victim that are adjacent to the area struck by pellets. This study presents a method that can be used in precisely this type of situation, allowing the estimation of shot distance in cases of partial pellet patterns. It is based on collecting distributions in test shots at several distances, and taking samples in the targets, constrained by the shape of the void and the pellet hit areas. Statistical descriptors of patterns are extracted from such samples, and fed into a neural network classifier, estimating shot ranges of distance.

  6. Short distance behaviour of the effective string

    CERN Document Server

    Caselle, M; Panero, M

    2004-01-01

    We study the Polyakov loop correlator in the (2+1) dimensional Z_2 gauge model. A novel algorithm that we have presented recently, allows us to reach high precision results for a large range of distances and temperatures, giving us a unique opportunity to test predictions of the effective Nambu-Goto string model. Here we focus on the regime of low temperatures and small distances. In contrast to the high temperature, large distance regime, we find that our numerical results are not well described by the two loop-prediction of the Nambu-Goto model. In addition we compare our data with those for the SU(2) and SU(3) gauge models in (2+1) dimensions obtained by other authors. We generalize the result of Luscher and Weisz for a boundary term in the interquark potential to the finite temperature case.

  7. [Panorama of nursing distance education in Brazil].

    Science.gov (United States)

    Rojo, Priscila Tagliaferro; Vieira, Sheila de Souza; Zem-Mascarenhas, Silvia Helena; Sandor, Elisane Regina; Vieira, Carla Roberta Sola de Paula

    2011-12-01

    The development of distance education is associated with the popularization and democratization of the accessibility to information and communication technologies. Nursing has been using this modality of education in both undergraduate and graduate courses, which has provided knowledge about other technologies, an easier accessibility, flexibility of time and space, and reduced costs. The objective of this study is map the national higher education distance nursing courses. This exploratory, descriptive study was developed by visiting governmental, non-governmental and institutional websites. Two undergraduate and nine graduate courses in nursing were found, which is considered to be a low number, considering that distance education is an appropriate pedagogical tool that permits to prepare a large number of nurses who are geographically dispersed and who do not have access to the conventional educational processes.

  8. The social distance theory of power.

    Science.gov (United States)

    Magee, Joe C; Smith, Pamela K

    2013-05-01

    We propose that asymmetric dependence between individuals (i.e., power) produces asymmetric social distance, with high-power individuals feeling more distant than low-power individuals. From this insight, we articulate predictions about how power affects (a) social comparison, (b) susceptibility to influence, (c) mental state inference and responsiveness, and (d) emotions. We then explain how high-power individuals' greater experienced social distance leads them to engage in more abstract mental representation. This mediating process of construal level generates predictions about how power affects (a) goal selection and pursuit, (b) attention to desirability and feasibility concerns, (c) subjective certainty, (d) value-behavior correspondence, (e) self-control, and (f) person perception. We also reassess the approach/inhibition theory of power, noting limitations both in what it can predict and in the evidence directly supporting its proposed mechanisms. Finally, we discuss moderators and methodological recommendations for the study of power from a social distance perspective.

  9. Optimal architectures for long distance quantum communication

    Science.gov (United States)

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D.; Jiang, Liang

    2016-02-01

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.

  10. Contextual Distance Refining for Image Retrieval

    KAUST Repository

    Islam, Almasri

    2014-09-16

    Recently, a number of methods have been proposed to improve image retrieval accuracy by capturing context information. These methods try to compensate for the fact that a visually less similar image might be more relevant because it depicts the same object. We propose a new quick method for refining any pairwise distance metric, it works by iteratively discovering the object in the image from the most similar images, and then refine the distance metric accordingly. Test show that our technique improves over the state of art in terms of accuracy over the MPEG7 dataset.

  11. Human recognition at a distance in video

    CERN Document Server

    Bhanu, Bir

    2010-01-01

    Most biometric systems employed for human recognition require physical contact with, or close proximity to, a cooperative subject. Far more challenging is the ability to reliably recognize individuals at a distance, when viewed from an arbitrary angle under real-world environmental conditions. Gait and face data are the two biometrics that can be most easily captured from a distance using a video camera. This comprehensive and logically organized text/reference addresses the fundamental problems associated with gait and face-based human recognition, from color and infrared video data that are

  12. An Introduction to Distance Measurement in Astronomy

    CERN Document Server

    de Grijs, Richard

    2011-01-01

    Distance determination is an essential technique in astronomy, and is briefly covered in most textbooks on astrophysics and cosmology. It is rarely covered as a coherent topic in its own right. When it is discussed the approach is frequently very dry, splitting the teaching into, for example, stars, galaxies and cosmologies, and as a consequence, books lack depth and are rarely comprehensive. Adopting a unique and engaging approach to the subject An Introduction to distance Measurement in Astronomy will take the reader on a journey from the solar neighbourhood to the edge of the Universe, dis

  13. PERSPECTIVES ON GROUP WORK IN DISTANCE LEARNING

    Directory of Open Access Journals (Sweden)

    Rune Sarromaa HAUSSTÄTTER

    2007-01-01

    Full Text Available Current distance education benefits greatly from educational software that makes group work possible for students who are separated in time and space. However, some students prefer distance education because they can work on their own. This paper explores how students react to expectations on behalf of the course provider to do their assignments in collaborative groups. They are seemingly both positively surprised by the challenges that group work offer, and they are less positive to the downsides of group work. The paper discusses both sides of the experiences and suggests why this might be a paradox to live with.

  14. Explorations in Physics and Distance Learning

    Science.gov (United States)

    Caviness, Kenneth

    2010-02-01

    How can the activity-based directed inquiry model be applied in a distance learning class? Lessons learned during a two-year pilot program (2007-2009) using the ``Explorations in Physics'' curriculum (David P. Jackson, Priscilla W. Laws, Scott V. Franklin) for a class taught over the internet using VCAM technology. The author reports on the successes, difficulties and surprises of teaching an exploratory physics class at a distance, where teacher-student interaction occurred via high-definition camera and big screen, two-way sight and sound carried by high-speed internet. )

  15. Short-Distance Structure of Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Douglas Higinbotham, Eliazer Piasetzky, Stephen Wood

    2011-06-01

    One of Jefferson Lab's original missions was to further our understanding of the short-distance structure of nuclei. In particular, to understand what happens when two or more nucleons within a nucleus have strongly overlapping wave-functions; a phenomena commonly referred to as short-range correlations. Herein, we review the results of the (e,e'), (e,e'p) and (e,e'pN) reactions that have been used at Jefferson Lab to probe this short-distance structure as well as provide an outlook for future experiments.

  16. DISTANCE FORMAT OF PSYCHOLOGICAL COMPETENCIES DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Yunona M. Ilina

    2010-08-01

    Full Text Available The paper is focused on the conceptual model of the distance learning course (DLC “Success” aimed at the development of psychological competencies. The course was developed on the basis of design technology method and intended for adults that are in need of psychological competencies development, i.e. inhabitants of villages, towns, people with special needs, university faculty, trainers and social workers, educators, who want to use DLC in the process of psychological competencies development that are the result in enhancement of life quality. The structure of the distance learning course “Success” and underlying principles is described.

  17. Robustness of Distance-to-Default

    DEFF Research Database (Denmark)

    Jessen, Cathrine; Lando, David

    2015-01-01

    Distance-to-default (DD) is a measure of default risk derived from observed stock prices and book leverage using the structural credit risk model of Merton (1974). Despite the simplifying assumptions that underlie its derivation, DD has proven empirically to be a strong predictor of default. We use...... is successful in ranking firms’ default probabilities, even if the underlying model assumptions are altered. A possibility of large jumps in asset value or stochastic volatility challenge the robustness of DD. We propose a volatility adjustment of the distance-to-default measure that significantly improves...... the ranking of firms with stochastic volatility, but this measure is less robust to model misspecifications than DD....

  18. Markets, Distance Education, and Australian Higher Education

    Directory of Open Access Journals (Sweden)

    Ted Nunan

    2005-03-01

    Full Text Available The paper argues that the Australian university system is unstable. There will be significant change as government implements its reform agenda and even more radical change if it moves to new deregulation. The role of distance education in university education needs to be analyzed against this ‘market’ agenda of government in terms of characteristics of markets and market behavior. After a scan of the current role, the paper looks at two scenarios (regulated and deregulated for distance education in university teaching and learning in Australia.

  19. Challenges in the Provision of Library Services for Distance ...

    African Journals Online (AJOL)

    Challenges in the Provision of Library Services for Distance Education: A Case Study of ... focus has turned to the role of libraries in the distance learning process. ... and those who design and implement such distance education programmes.

  20. Deciphering the Distance between Distance Education and Working Professionals in Difficult Geographies

    Science.gov (United States)

    Pandey, Jatin; Singh, Manjari

    2015-01-01

    This study investigates the factors that draw working professionals towards distance education programs, and the factors that sustain their distance education experience. The study is conducted in difficult terrains of Uttarakhand, a hilly state in India which helps us investigate the phenomenon in difficult geographies. Through interviews of ten…