WorldWideScience

Sample records for wave patterns information

  1. Spatiotemporal Wave Patterns: Information Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mikhail Rabinovich; Lev Tsimring

    2006-01-20

    Pattern formation has traditionally been studied in non-equilibrium physics from the viewpoint of describing the basic structures and their interactions. While this is still an important area of research, the emphasis in the last few years has shifted towards analysis of specific properties of patterns in various complex media. For example, diverse and unexpected phenomena occur in neuro-like media that are characterized by highly non-trivial local dynamics. We carried out an active research program on analysis of spatio-temporal patterns in various physical systems (convection, oscillating fluid layer, soap film), as well as in neuro-like media, with an emphasis on informational aspects of the dynamics. Nonlinear nonequilibrium media and their discrete analogs have a unique ability to represent, memorize, and process the information contained in spatio-temporal patterns. Recent neurophysiological experiments demonstrated a certain universality of spatio-temporal representation of information by neural ensembles. Information processing is also revealed in the spatio-temporal dynamics of cellular patterns in nonequilibrium media. It is extremely important for many applications to study the informational aspects of these dynamics, including the origins and mechanisms of information generation, propagation and storage. Some of our results are: the discovery of self-organization of periodically oscillatory patterns in chaotic heterogeneous media; the analysis of the propagation of the information along a chaotic media as function of the entropy of the signal; the analysis of wave propagation in discrete non-equilibrium media with autocatalytic properties, which simulates the calcium dynamics in cellular membranes. Based on biological experiments we suggest the mechanism by which the spatial sensory information is transferred into the spatio-temporal code in the neural media. We also found a new mechanism of self-pinning in cellular structures and the related phenomenon

  2. Streaming patterns in Faraday waves

    CERN Document Server

    Périnet, Nicolas; Urra, Héctor; Mujica, Nicolás; Gordillo, Leonardo

    2016-01-01

    Waves patterns in the Faraday instability have been studied for decades. Besides the rich dynamics that can be observed on the waves at the interface, Faraday waves hide beneath them an elusive range of flow patterns --or streaming patterns-- which have not been studied in detail until now. The streaming patterns are responsible for a net circulation in the flow which are reminiscent of convection cells. In this article, we analyse these streaming flows by conducting experiments in a Faraday-wave setup. To visualize the flows, tracers are used to generate both trajectory maps and to probe the streaming velocity field via Particle Image Velocimetry (PIV). We identify three types of patterns and experimentally show that identical Faraday waves can mask streaming patterns that are qualitatively very different. Next we propose a three-dimensional model that explains streaming flows in quasi-inviscid fluids. We show that the streaming inside the fluid arises from a complex coupling between the bulk and the boundar...

  3. Waves of information technology

    OpenAIRE

    Case, Donald O.

    2009-01-01

    This is a history of the various concepts and technologies of a public information utility. The first “wave” existed from about 1900 to 1945, and was centered on the idea of microfilm as an access mechanism to the world’s information. The advocates included Paul Otlet (1934) of Belgium, Englishman H.G. Wells’ vision of a “World Brain” (1938), and American Vanevar Bush and his “Memex” device (1945). The second wave consisted of the development of computers and their networks, which eventual...

  4. Information Demand Pattern for Teams

    Directory of Open Access Journals (Sweden)

    Dirk Stamer

    2016-04-01

    Full Text Available Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of information demand patterns from single roles to teams. Using the knowledge intensive field of project management, the paper shows how to apply the concept of information demand patterns for a whole team. The contributions of this work are (1 the methodical approach to develop information demand patterns for teams, (2 an actual information demand pattern for a steering committee in the context of project management, (3 reflections on the differences between role patterns and team patterns.

  5. Waves and aggregation patterns in myxobacteria

    Science.gov (United States)

    Igoshin, Oleg A.; Welch, Roy; Kaiser, Dale; Oster, George

    2004-03-01

    Under starvation conditions, a population of myxobacteria aggregates to build a fruiting body whose shape is species-specific and within which the cells sporulate. Early in this process, cells often pass through a "ripple phase" characterized by traveling linear, concentric, and spiral waves. These waves are different from the waves observed during slime mold aggregation that depend on diffusible morphogens, because myxobacteria communicate by direct contact. The difference is most dramatic when waves collide: rather than annihilating one another, myxobacterial waves appear to pass through one another unchanged. Under certain conditions, the spacing and location of the nascent fruiting bodies is determined by the wavelength and pattern of the waves. Later in fruiting body development, waves are replaced by streams of cells that circulate around small initial aggregates enlarging and rounding them. Still later, pairs of motile aggregates coalesce to form larger aggregates that develop into fruiting bodies. Here we present a mathematical model that quantitatively explains these wave and aggregation phenomena.

  6. Information Demand Pattern for Teams

    OpenAIRE

    Dirk Stamer; Kurt Sandkuhl; Veronika Zeiner

    2016-01-01

    Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of informa...

  7. Pattern recognition of quantum information based on pattern-distance

    Institute of Scientific and Technical Information of China (English)

    Dong Daoyi; Chen Zonghai; Jiang Shengxiang

    2005-01-01

    Looking upon every encoding state of quantum information systems as a quantum information pattern, A kind of pattern-distance between different patterns as a measurement of comparability of quantum information patterns is defined, and two kinds of recognition algorithms based on pattern-distance for quantum information are proposed. They can respectively recognize quantum information with known objective pattern and unknown objective pattern. In the two algorithms, the phases and occurrence probabilities of different eigenpatterns of quantum information are sufficiently considered. Two examples demonstrate the feasibility and effectiveness of the two recognition methods. These algorithms point out a new and important path for applications of quantum information and pattern recognition.

  8. Transmission of Information by Longitudinal Electromagnetic Waves

    CERN Document Server

    Barashenkov, V S; Yuriev, M Z

    2001-01-01

    In Maxwell electrodynamics longitudinal wave irradiation is strongly forbidden by the so-called gauge invariance. However, these waves are present in virtual quantum processes and they can be used to transfer information at macroscopic distances by the displacement of the interference picture due to the change of the phase of electron wave function. The transmission can be carried out so that it will be hidden for usual observation.

  9. The Informational Patterns of Laughter

    Directory of Open Access Journals (Sweden)

    Pedro C. Marijuán

    2003-06-01

    Full Text Available Abstract: Laughter is one of the most characteristic -and enigmatic- communicational traits of human individuals. Its analysis has to take into account a variety of emotional, social, cognitive, and communicational factors densely interconnected. In this article we study laughter just as an auditive signal (as a 'neutral' information carrier, and we compare its structure with the regular traits of linguistic signals. In the experimental records of human laughter that we have performed, the most noticeable trait is the disorder content of frequencies. In comparison with the sonograms of vowels, the information content of which appears as a characteristic, regular function of the first vibration modes of the dynamic system formed, for each vowel, by the vocal cords and the accompanying resonance of the vocalization apparatus, the sonograms of laughter are highly irregular. In the episodes of laughter, a highly random content in frequencies appears, reason why it cannot be considered as a genuine codification of patterned information like in linguistic signals. In order to numerically gauge the disorder content of laughter frequencies, we have performed several "entropy" measures of the spectra -trying to unambiguously identify spontaneous laughter from "faked", articulated laughter. Interestingly, Shannon's entropy (the most natural candidate performs rather poorly.

  10. Compactification of nonlinear patterns and waves.

    Science.gov (United States)

    Rosenau, Philip; Kashdan, Eugene

    2008-12-31

    We present a nonlinear mechanism(s) which may be an alternative to a missing wave speed: it induces patterns with a compact support and sharp fronts which propagate with a finite speed. Though such mechanism may emerge in a variety of physical contexts, its mathematical characterization is universal, very simple, and given via a sublinear substrate (site) force. Its utility is shown studying a Klein-Gordon -u(tt) + [phi/(u(x)]x = P'(u) equation, where phi'(sigma) = sigma + beta sigma3 and endowed with a subquadratic site potential P(u) approximately /1-u2/(alpha+1), 0 < or = alpha < 1, and the Schrödinger iZt + inverted delta2 Z = G(/Z/)Z equation in a plane with G(A) = gammaA(-delta) - sigmaA2, 0 < delta < or = 1.

  11. How animals get their skin patterns: fish pigment pattern as a live Turing wave.

    Science.gov (United States)

    Kondo, Shigeru; Iwashita, Motoko; Yamaguchi, Motoomi

    2009-01-01

    It is more than fifty years since Alan Turing first presented the reaction-diffusion (RD) model, to account for the mechanism of biological pattern formation. In the paper entitled "The chemical basis of morphogenesis", Turing concluded that spatial patterns autonomously made in the embryo are generated as the stationary wave of the chemical (cellular) reactions. Although this novel idea was paid little attention by experimental biologists, recent experimental data are suggesting that the RD mechanism really functions in some of the course of animal development. Among the phenomena in which involvement of the RD mechanism is suspected, the striped pigment pattern of zebrafish has been highlighted as an ideal model system for the following reasons: the stationary wave made by the RD mechanism stays alive and can be observed only in the fish skin; and in zebrafish, we can utilize genomic information and molecular genetic techniques to clarify the molecular basis of pattern formation. In this review, we summarize recent progresses in the study of zebrafish pigment pattern formation that is uncovering how the RD wave is made and maintained in the skin.

  12. Evolutions of Wave Patterns in Whitham-Broer-Kaup Equation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zheng-Di; BI Qin-Sheng

    2009-01-01

    Upon investigation of the parameter influence on the structure of WBK equation, transition boundaries are derived. All possible bounded waves as well as the existence conditions are obtained. The evolution of waves with variation of the parameters is discussed in detail, which reveals the bifurcation mechanism between different wave patterns.

  13. Optical method for inspecting LSI patterns using reflected diffraction waves.

    Science.gov (United States)

    Kimura, S; Suda, K; Hase, S; Munakata, C

    1988-03-15

    An optical inspection method has been developed for finding defects in LSI lithographic patterns. A focused He-Ne laser beam scans the patterns on a wafer. The reflected diffraction waves around the wafer are observed. These diffraction waves indicate whether the patterns contain defects. To implement this judgment rapidly, signals of the waves characterizing the patterns are input directly into the address lines of random access memories. The system can detect a defect of ~0.8-microm diameter and inspect a 1-cm(2) chip in 9 s.

  14. 2-D traveling-wave patterns in binary fluid convection

    Energy Technology Data Exchange (ETDEWEB)

    Surko, C.M.; Porta, A.L. [Univ. of California, La Jolla, CA (United States)

    1996-12-31

    An overview is presented of recent experiments designed to study two-dimensional traveling-wave convection in binary fluid convection in a large aspect ratio container. Disordered patterns are observed when convection is initiated. As time proceeds, they evolve to more ordered patterns, consisting of several domains of traveling-waves separated by well-defined domain boundaries. The detailed character of the patterns depends sensitively on the Rayleigh number. Numerical techniques are described which were developed to provide a quantitative characterization of the traveling-wave patterns. Applications of complex demodulation techniques are also described, which make a detailed study of the structure and dynamics of the domain boundaries possible.

  15. Developmental waves in myxobacteria: A distinctive pattern formation mechanism

    Science.gov (United States)

    Igoshin, Oleg A.; Neu, John; Oster, George

    2004-10-01

    In early stages of their development, starving myxobacteria organize their motion to produce a periodic pattern of traveling cell density waves. These waves arise from coordination of individual cell reversals by contact signaling when they collide. Unlike waves generated by reaction-diffusion instabilities, which annihilate on collision, myxobacteria waves appear to pass through one another unaffected. Here we analyze a mathematical model of these waves developed earlier [Igoshin , Proc. Natl. Acad. Sci. USA 98, 14 913 (2001)]. The mechanisms which generate and maintain the density waves are clearly revealed by tracing the reversal loci of individual cells. An evolution equation of reversal point density is derived in the weak-signaling limit. Linear stability analysis determines parameters favorable for the development of the waves. Numerical solutions demonstrate the stability of the fully developed nonlinear waves.

  16. Retinal waves coordinate patterned activity throughout the developing visual system.

    Science.gov (United States)

    Ackman, James B; Burbridge, Timothy J; Crair, Michael C

    2012-10-11

    The morphological and functional development of the vertebrate nervous system is initially governed by genetic factors and subsequently refined by neuronal activity. However, fundamental features of the nervous system emerge before sensory experience is possible. Thus, activity-dependent development occurring before the onset of experience must be driven by spontaneous activity, but the origin and nature of activity in vivo remains largely untested. Here we use optical methods to show in live neonatal mice that waves of spontaneous retinal activity are present and propagate throughout the entire visual system before eye opening. This patterned activity encompassed the visual field, relied on cholinergic neurotransmission, preferentially initiated in the binocular retina and exhibited spatiotemporal correlations between the two hemispheres. Retinal waves were the primary source of activity in the midbrain and primary visual cortex, but only modulated ongoing activity in secondary visual areas. Thus, spontaneous retinal activity is transmitted through the entire visual system and carries patterned information capable of guiding the activity-dependent development of complex intra- and inter-hemispheric circuits before the onset of vision.

  17. Generation of 1D interference patterns of Bloch surface waves

    Science.gov (United States)

    Kadomina, E. A.; Bezus, E. A.; Doskolovich, L. L.

    2016-09-01

    Interference patterns of Bloch surface waves with a period that is significantly less than the wavelength of incident radiation are formed using dielectric diffraction gratings located on the surface of photonic crystal. The simulation based on electromagnetic diffraction theory is used to demonstrate the possibility of high-quality interference patterns due to resonant enhancement of higher evanescent diffraction orders related to the excitation of the Bloch surface waves. The contrast of the interference patterns is close to unity, and the period is less than the period of the diffraction structure by an order of magnitude.

  18. Waves and Patterns in Chemical and Biological Media

    Science.gov (United States)

    Swinney, Harry L.; Krinsky, Valentin I.

    1991-12-01

    These 28 contributions by leading researchers - from such diverse disciplines as chemistry, biology, physics, mathematics, and physiology - describe recent experiments, numerical simulations, and theoretical analyses of the formation of spatial patterns in chemical and biological systems. Chemical patterns have been systematically studied since the field was established by Alan Turing's landmark 1952 paper, "The chemical basis for morphogenesis," yet only recently have new experimental techniques and numerical analyses of reaction-diffusion equations opened the way to understanding stationary and traveling wave patterns. This collection summarizes the exciting developments in this rapidly growing field. It shows that some biological patterns have been found to be strikingly similar to patterns found in simple, well-controlled laboratory chemical systems, that new chemical reactor designs make it possible to sustain chemical patterns and to study transitions between different kinds of patterns, and that nearly 40 years after Turing's paper, the patterns predicted by Turing have finally been observed in laboratory experiments. Harry L. Swinney is Sid Richardson Foundation Regents Chair, Department of Physics, and Director of the Center for Nonlinear Dynamics at the University of Texas at Austin. Valentin I. Krinsky is Head of the Autowave Laboratory, Institute of Biological Physics, Academy of Sciences, Pushchino, USSR. Chapters cover: Spiral, Ring, and Scroll Patterns: Experiments. Spiral, Ring, and Scroll Patterns: Theory and Simulations. Fronts and Turing Patterns. Waves and Patterns in Biological Systems.

  19. Waves, Information, and Foundations of Physics

    Science.gov (United States)

    Garola, Claudio

    1. This book arises from a Conference Proceedings series edited by the Italian Physical Society and collects most of the lectures given at the International Conference Waves, Information, and Foundations of Physics, held in Florence in September 1996 in honour of Giuliano Toraldo di Francia's 80th birthday. It begins with an Introduction (in Italian) in which some prominent colleagues of the guest of honour review his brilliant career, wise teaching, and wide interests. Then the book presents 28 papers (in English) that deal with physical, philosophical, and historical topics belonging to several fields in which Toraldo di Francia was active during his long and successful life as a scientific researcher.

  20. Enhanced Pattern Representation in Information Extraction

    Institute of Scientific and Technical Information of China (English)

    廖乐健; 曹元大; 张映波

    2004-01-01

    Traditional pattern representation in information extraction lack in the ability of representing domain-specific concepts and are therefore devoid of flexibility. To overcome these restrictions, an enhanced pattern representation is designed which includes ontological concepts, neighboring-tree structures and soft constraints. An information-extraction inference engine based on hypothesis-generation and conflict-resolution is implemented. The proposed technique is successfully applied to an information extraction system for Chinese-language query front-end of a job-recruitment search engine.

  1. Baby booms and busts: waves in fertility patterns

    NARCIS (Netherlands)

    Beets, G.C.N.

    2009-01-01

    Fertility curves sometimes resemble sea waves. During periods that the fertility age patterns change, according to whatever reason, 'this sea' may become very turbulent. Also other sea-like phenomena, for example tsunamis, are discernible in fertility behaviour. This article gives a short overview

  2. Characterization and modification of cavitation pattern in shock wave lithotripsy

    NARCIS (Netherlands)

    Arora, Manish; Ohl, Claus-Dieter; Liebler, Marko

    2004-01-01

    The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTD-calculations. Second, we describe a met

  3. Baby booms and busts: waves in fertility patterns

    NARCIS (Netherlands)

    Beets, G.C.N.

    2009-01-01

    Fertility curves sometimes resemble sea waves. During periods that the fertility age patterns change, according to whatever reason, 'this sea' may become very turbulent. Also other sea-like phenomena, for example tsunamis, are discernible in fertility behaviour. This article gives a short overview o

  4. Numerical simulation of supersquare patterns in Faraday waves

    Science.gov (United States)

    Kahouadji, L.; Périnet, N.; Tuckerman, L. S.; Shin, S.; Chergui, J.; Juric, D.

    2015-06-01

    We report the first simulations of the Faraday instability using the full three-dimensional Navier-Stokes equations in domains much larger than the characteristic wavelength of the pattern. We use a massively parallel code based on a hybrid Front-Tracking/Level-set algorithm for Lagrangian tracking of arbitrarily deformable phase interfaces. Simulations performed in rectangular and cylindrical domains yield complex patterns. In particular, a superlattice-like pattern similar to those of [Douady & Fauve, Europhys. Lett. 6, 221-226 (1988); Douady, J. Fluid Mech. 221, 383-409 (1990)] is observed. The pattern consists of the superposition of two square superlattices. We conjecture that such patterns are widespread if the square container is large compared to the critical wavelength. In the cylinder, pentagonal cells near the outer wall allow a square-wave pattern to be accommodated in the center.

  5. Vector wave diffraction pattern of slits masked by polarizing devices

    Indian Academy of Sciences (India)

    Mohammad Tahir; K Bhattacharya; A K Chakraborty

    2012-03-01

    Polarization property is important to the optical imaging system. It has recently been understood that the polarization properties of light can be fruitfully used for improving the characteristics of imaging system that includes polarizing devices. The vector wave imagery lends an additional degree of freedom that can be utilized for obtaining results that are unobtainable in scalar wave imagery. This calls for a systematic study of diffraction properties of different apertures using polarization-sensitive devices. In the present paper, we have studied the Fraunhofer diffraction pattern of slits masked by different kinds of polarizing devices which introduce a phase difference between the two orthogonal components of the incident beam.

  6. Spin-wave interference patterns created by spin-torque nano-oscillators for memory and computation

    Energy Technology Data Exchange (ETDEWEB)

    Macia, Ferran; Kent, Andrew D [Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Hoppensteadt, Frank C, E-mail: fmb2@nyu.edu [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States)

    2011-03-04

    Magnetization dynamics in nanomagnets has attracted broad interest since it was predicted that a dc current flowing through a thin magnetic layer can create spin-wave excitations. These excitations are due to spin momentum transfer, a transfer of spin angular momentum between conduction electrons and the background magnetization, that enables new types of information processing. Here we show how arrays of spin-torque nano-oscillators can create propagating spin-wave interference patterns of use for memory and computation. Memristic transponders distributed on the thin film respond to threshold tunnel magnetoresistance values, thereby allowing spin-wave detection and creating new excitation patterns. We show how groups of transponders create resonant (reverberating) spin-wave interference patterns that may be used for polychronous wave computation and information storage.

  7. Information and perception of meaningful patterns.

    Directory of Open Access Journals (Sweden)

    Maria M Del Viva

    Full Text Available The visual system needs to extract the most important elements of the external world from a large flux of information in a short time for survival purposes. It is widely believed that in performing this task, it operates a strong data reduction at an early stage, by creating a compact summary of relevant information that can be handled by further levels of processing. In this work we formulate a model of early vision based on a pattern-filtering architecture, partly inspired by high-speed digital data reduction in experimental high-energy physics (HEP. This allows a much stronger data reduction than models based just on redundancy reduction. We show that optimizing this model for best information preservation under tight constraints on computational resources yields surprisingly specific a-priori predictions for the shape of biologically plausible features, and for experimental observations on fast extraction of salient visual features by human observers. Interestingly, applying the same optimized model to HEP data acquisition systems based on pattern-filtering architectures leads to specific a-priori predictions for the relevant data patterns that these devices extract from their inputs. These results suggest that the limitedness of computing resources can play an important role in shaping the nature of perception, by determining what is perceived as "meaningful features" in the input data.

  8. Probability of US Heat Waves Affected by a Subseasonal Planetary Wave Pattern

    Science.gov (United States)

    Teng, Haiyan; Branstator, Grant; Wang, Hailan; Meehl, Gerald A.; Washington, Warren M.

    2013-01-01

    Heat waves are thought to result from subseasonal atmospheric variability. Atmospheric phenomena driven by tropical convection, such as the Asian monsoon, have been considered potential sources of predictability on subseasonal timescales. Mid-latitude atmospheric dynamics have been considered too chaotic to allow significant prediction skill of lead times beyond the typical 10-day range of weather forecasts. Here we use a 12,000-year integration of an atmospheric general circulation model to identify a pattern of subseasonal atmospheric variability that can help improve forecast skill for heat waves in the United States. We find that heat waves tend to be preceded by 15-20 days by a pattern of anomalous atmospheric planetary waves with a wavenumber of 5. This circulation pattern can arise as a result of internal atmospheric dynamics and is not necessarily linked to tropical heating.We conclude that some mid-latitude circulation anomalies that increase the probability of heat waves are predictable beyond the typical weather forecast range.

  9. Wave-Based Turing Machine: Time Reversal and Information Erasing.

    Science.gov (United States)

    Perrard, S; Fort, E; Couder, Y

    2016-08-26

    The investigation of dynamical systems has revealed a deep-rooted difference between waves and objects regarding temporal reversibility and particlelike objects. In nondissipative chaos, the dynamic of waves always remains time reversible, unlike that of particles. Here, we explore the dynamics of a wave-particle entity. It consists in a drop bouncing on a vibrated liquid bath, self-propelled and piloted by the surface waves it generates. This walker, in which there is an information exchange between the particle and the wave, can be analyzed in terms of a Turing machine with waves as the information repository. The experiments reveal that in this system, the drop can read information backwards while erasing it. The drop can thus backtrack on its previous trajectory. A transient temporal reversibility, restricted to the drop motion, is obtained in spite of the system being both dissipative and chaotic.

  10. Wave-Based Turing Machine: Time Reversal and Information Erasing

    Science.gov (United States)

    Perrard, S.; Fort, E.; Couder, Y.

    2016-08-01

    The investigation of dynamical systems has revealed a deep-rooted difference between waves and objects regarding temporal reversibility and particlelike objects. In nondissipative chaos, the dynamic of waves always remains time reversible, unlike that of particles. Here, we explore the dynamics of a wave-particle entity. It consists in a drop bouncing on a vibrated liquid bath, self-propelled and piloted by the surface waves it generates. This walker, in which there is an information exchange between the particle and the wave, can be analyzed in terms of a Turing machine with waves as the information repository. The experiments reveal that in this system, the drop can read information backwards while erasing it. The drop can thus backtrack on its previous trajectory. A transient temporal reversibility, restricted to the drop motion, is obtained in spite of the system being both dissipative and chaotic.

  11. Sentence Level Information Patterns for Novelty Detection

    Science.gov (United States)

    2006-07-01

    Information Patterns for Novelty Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...technology transfer arm, has sold the worldwide marketing rights to the drug Daca in return for cash payments and royalties should the drug be marketed...34> Stockbroker Lehman Brothers estimates that it may eventually generate Dollars 250m in sales.</s> <s docid="FT943-9461" num=൓"> Daca is still in the early

  12. Evaluation Statistics Computed for the Wave Information Studies (WIS)

    Science.gov (United States)

    2016-07-01

    wave models , including those of WIS, are influenced by meteorological forcing parameters, representation of the geographic area (e.g., bathymetry...statistical metrics to wave model evaluation are found in Zambresky (1989) and Cardone et al. (1996). These statistics were calculated in the...describes the statistical metrics used by the Wave Information Studies (WIS) and produced as part of the model evaluation process. INTRODUCTION: The

  13. Spatial rogue waves in a photorefractive pattern-forming system.

    Science.gov (United States)

    Marsal, N; Caullet, V; Wolfersberger, D; Sciamanna, M

    2014-06-15

    We have experimentally analyzed pattern formation in an optical system composed of a bulk photorefractive crystal subjected to a single optical feedback. In a highly nonlinear regime far above the modulational instability threshold, we are reporting on turbulent spatiotemporal dynamics that leads to rare, intense localized optical peaks. We have proven that the statistics and features of those peaks correspond to the signatures of two-dimensional spatial rogue events. These optical rogue waves occur erratically in space and time and live typically the same amount of time as the response time of the photorefractive material.

  14. Correspondence between some wave patterns and Lissajous figures

    Science.gov (United States)

    Górska, K. J.; Makowski, A. J.; Dembinski, S. T.

    2006-10-01

    We study the connections between some specially entangled stationary states and the classical periodic trajectories of two non-interacting oscillators. The latter are well-known Lissajous figures, which are shown to run precisely over the apogees of their corresponding probability distributions in the above states. We propose in this work a very simple criterion enabling us to obtain the best agreement between the quantum and the classical images. Finally, our results are successfully applied to the interpretation of some experimentally observed wave patterns.

  15. Correspondence between some wave patterns and Lissajous figures

    Energy Technology Data Exchange (ETDEWEB)

    Gorska, K J; Makowski, A J; Dembinski, S T [Institute of Physics, Nicolaus Copernicus University, ul. Grudziadzka 5, 87-100 Torun (Poland)

    2006-10-20

    We study the connections between some specially entangled stationary states and the classical periodic trajectories of two non-interacting oscillators. The latter are well-known Lissajous figures, which are shown to run precisely over the apogees of their corresponding probability distributions in the above states. We propose in this work a very simple criterion enabling us to obtain the best agreement between the quantum and the classical images. Finally, our results are successfully applied to the interpretation of some experimentally observed wave patterns.

  16. Millimeter Wave MIMO Channel Estimation Using Overlapped Beam Patterns and Rate Adaptation

    Science.gov (United States)

    Kokshoorn, Matthew; Chen, He; Wang, Peng; Li, Yonghui; Vucetic, Branka

    2017-02-01

    This paper is concerned with the channel estimation problem in Millimeter wave (mmWave) wireless systems with large antenna arrays. By exploiting the inherent sparse nature of the mmWave channel, we first propose a fast channel estimation (FCE) algorithm based on a novel overlapped beam pattern design, which can increase the amount of information carried by each channel measurement and thus reduce the required channel estimation time compared to the existing non-overlapped designs. We develop a maximum likelihood (ML) estimator to optimally extract the path information from the channel measurements. Then, we propose a novel rate-adaptive channel estimation (RACE) algorithm, which can dynamically adjust the number of channel measurements based on the expected probability of estimation error (PEE). The performance of both proposed algorithms is analyzed. For the FCE algorithm, an approximate closed-form expression for the PEE is derived. For the RACE algorithm, a lower bound for the minimum signal energy-to-noise ratio required for a given number of channel measurements is developed based on the Shannon-Hartley theorem. Simulation results show that the FCE algorithm significantly reduces the number of channel estimation measurements compared to the existing algorithms using non-overlapped beam patterns. By adopting the RACE algorithm, we can achieve up to a 6dB gain in signal energy-to-noise ratio for the same PEE compared to the existing algorithms.

  17. Patient information leaflets for extracorporeal shock wave lithotripsy: questionnaire survey

    OpenAIRE

    Askari, A.; Shergill, I.

    2012-01-01

    Objectives To compare the level of information provided in extracorporeal shock wave lithotripsy (ESWL) patient information leaflets in the London and East of England Deaneries Design All trusts in the London and East of England Deanery who offer an ESWL service were contacted and leaflets were compared Setting London and East of England Deanery Participants Alan Askari, Iqbal Shergill Main outcome measures Examination of key information that was communicated to ESWL patients via leaflets Res...

  18. Damage pattern and damage progression on breakwater roundheads under multidirectional waves

    DEFF Research Database (Denmark)

    Comola, F.; Andersen, Thomas Lykke; Martinelli, L.;

    2014-01-01

    characteristics. The damage progression is observed dependent on significant wave height and peak wave period, but not on the directional spreading and the spectral width of the incident waves. Combining the results of both damage pattern and damage progression, a stability formula for the distribution of damage......An experimental model test study is carried out to investigate damage pattern and progression on a rock armoured breakwater roundhead subjected to multidirectional waves. Concerning damage pattern, the most critical sector is observed to shift leeward with increasing wave period. Taking angles...... relative to mean wave direction, the critical sector is observed in the sector 10°–55° for short waves and in the sector 100°–145° for long waves. A probabilistic approach is developed to predict for one typical roundhead geometry the damage distribution depending on the incomingwaves and structural...

  19. Intelligent feature selection techniques for pattern classification of Lamb wave signals

    Energy Technology Data Exchange (ETDEWEB)

    Hinders, Mark K.; Miller, Corey A. [College of William and Mary, Department of Applied Science, Williamsburg, Virginia 23187-8795 (United States)

    2014-02-18

    Lamb wave interaction with flaws is a complex, three-dimensional phenomenon, which often frustrates signal interpretation schemes based on mode arrival time shifts predicted by dispersion curves. As the flaw severity increases, scattering and mode conversion effects will often dominate the time-domain signals, obscuring available information about flaws because multiple modes may arrive on top of each other. Even for idealized flaw geometries the scattering and mode conversion behavior of Lamb waves is very complex. Here, multi-mode Lamb waves in a metal plate are propagated across a rectangular flat-bottom hole in a sequence of pitch-catch measurements corresponding to the double crosshole tomography geometry. The flaw is sequentially deepened, with the Lamb wave measurements repeated at each flaw depth. Lamb wave tomography reconstructions are used to identify which waveforms have interacted with the flaw and thereby carry information about its depth. Multiple features are extracted from each of the Lamb wave signals using wavelets, which are then fed to statistical pattern classification algorithms that identify flaw severity. In order to achieve the highest classification accuracy, an optimal feature space is required but it’s never known a priori which features are going to be best. For structural health monitoring we make use of the fact that physical flaws, such as corrosion, will only increase over time. This allows us to identify feature vectors which are topologically well-behaved by requiring that sequential classes “line up” in feature vector space. An intelligent feature selection routine is illustrated that identifies favorable class distributions in multi-dimensional feature spaces using computational homology theory. Betti numbers and formal classification accuracies are calculated for each feature space subset to establish a correlation between the topology of the class distribution and the corresponding classification accuracy.

  20. Massive to gauge field reduction and gravitational wave zone information

    CERN Document Server

    Deser, S

    2016-01-01

    We show explicitly that massive, Abelian, vector, just like (properly defined) massive tensor, fields limit smoothly to their massless, gauge, versions: they emit only maximal helicity radiation and mediate Coulomb and (special relativistic) Newtonian, forces between their (conserved) sources. Our main motivation, though, is to show that the recent gravitational wave detection probably cannot directly rule out very long-range gravity: Even though the waves were emitted in a strong field regime, their being detected in the weak field wave zone means the above equivalences apply. There remains the, not unlikely, possibility that no strong field generation of radiation in massive models can reproduce the observed ring-down patterns. Separately, the smooth linear limiting behaviors show that the discontinuity lies not in the mass alone, but rather in Abelian versus non-Abelian, Yang-Mills and General Relativity, regimes, whose respective massive versions are known to be non-physical.

  1. AdS plane waves, entanglement and mutual information

    CERN Document Server

    Mukherjee, Debangshu

    2014-01-01

    $AdS$ plane wave backgrounds are dual to CFT excited states with energy momentum density $T_{++}=Q$. Building on previous work on entanglement entropy in these and nonconformal brane plane wave backgrounds, we first describe a phenomenological scaling picture for entanglement in terms of "entangling partons". We then study aspects of holographic mutual information in these backgrounds for two strip shaped subsystems, aligned parallel or orthogonal to the flux. We focus on the wide ($Ql^d\\gg 1$) and narrow ($Ql^d\\ll 1$) strip regimes. In the wide strip regime, mutual information exhibits growth with the individual strip sizes and a disentangling transition as the separation between the strips increases, whose behaviour is distinct from the ground and thermal states. In the narrow strip case, our calculations have parallels with "entanglement thermodynamics" for these $AdS$ plane wave deformations. We also discuss some numerical analysis.

  2. Stress wave velocity patterns in the longitudinal-radial plane of trees for defect diagnosis

    Science.gov (United States)

    Guanghui Li; Xiang Weng; Xiaocheng Du; Xiping Wang; Hailin Feng

    2016-01-01

    Acoustic tomography for urban tree inspection typically uses stress wave data to reconstruct tomographic images for the trunk cross section using interpolation algorithm. This traditional technique does not take into account the stress wave velocity patterns along tree height. In this study, we proposed an analytical model for the wave velocity in the longitudinal–...

  3. W-shaped soliton complexes and rogue-wave pattern transitions for the AB system

    Science.gov (United States)

    Wang, Xin; Liu, Chong

    2017-07-01

    With the help of a general Nth-order rogue wave solution in a compact determinant form for the AB system, we illuminate that, by suitably choosing the wavenumber and frequency of the background wave of the component A, W-shaped soliton complex containing a fixed number of algebraic solitons merging or separating with each other exists in the component A, and rogue-wave pattern transition between the four-petaled structure and dark structure occurs in the component B. The more complicated rogue-wave pattern transitions due to the nonlinear superposition corresponding to the higher-order four-petaled rogue waves and higher-order dark rogue waves of fundamental, triangular and circular dynamical structures up to third order are demonstrated, respectively. The spectrum properties which are related to the rogue-wave pattern transitions are revealed.

  4. Patient information leaflets for extracorporeal shock wave lithotripsy: questionnaire survey

    Science.gov (United States)

    Askari, A; Shergill, I

    2012-01-01

    Objectives To compare the level of information provided in extracorporeal shock wave lithotripsy (ESWL) patient information leaflets in the London and East of England Deaneries Design All trusts in the London and East of England Deanery who offer an ESWL service were contacted and leaflets were compared Setting London and East of England Deanery Participants Alan Askari, Iqbal Shergill Main outcome measures Examination of key information that was communicated to ESWL patients via leaflets Results 12 trusts responded across the two deaneries. There was significant variation in the amount of information provided in the leaflets with some leaflets not containing an adequate level of instruction or information to patients Conclusions The authors propose that a national standardised information leaflet should be incorporated with the British Association of Urological Surgeons (BAUS) procedure specific information leaflet for ESWL procedures PMID:22666532

  5. Extracting Information from the Atom-Laser Wave Function UsingInterferometric Measurement with a Laser Standing-Wave Grating

    Institute of Scientific and Technical Information of China (English)

    刘正东; 武强; 曾亮; 林宇; 朱诗尧

    2001-01-01

    The reconstruction of the atom-laser wave function is performed using an interferometric measurement with a standing-wave grating, and the results of this scheme are studied. The relations between the measurement data and the atomic wave function are also presented. This scheme is quite applicable and effectively avoids the initial random phase problem of the method that employs the laser running wave. The information which is encoded in the atom-laser wave is extracted.

  6. Propagation of Surface Wave Along a Thin Plasma Column and Its Radiation Pattern

    Institute of Scientific and Technical Information of China (English)

    WANG Zhijiang; ZHAO Guowei; XU Yuemin; LIANG Zhiwei; XU Jie

    2007-01-01

    Propagation of the surface waves along a two-dimensional plasma column and the far-field radiation patterns are studied in thin column approximation. Wave phase and attenuation coefficients are calculated for various plasma parameters. The radiation patterns are shown. Results show that the radiation patterns are controllable by flexibly changing the plasma length and other parameters in comparison to the metal monopole antenna. It is meaningful and instructional for the optimization of the plasma antenna design.

  7. Interfacial wave patterns and their transitions in gas-liquid two-phase flow through horizontal ducts

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The interfacial wave patterns and their transition characteristics in gas-liquid two-phase flow through rectangular and circular horizontal conduits are investigated.The interfacial waves were traced and recorded by using conductance probes.With the experimental observation and the analysis,some kinds of different interfacial waves were distinguished and dfined,and then the interfacial wave patterns were given,which were compared with previous results.The interfacial wave transition mechanism between each interfacial wave pattern was discussed and a set of transition equations were presented to predict the interfacial wave pattern transitions.The repdictive results are in good agreement with the experimental data.

  8. Efficient computation of steady, 3D water-wave patterns

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.

    2003-01-01

    Numerical methods for the computation of stationary free surfaces is the subject of much current research in computational engineering. The present report is directed towards free surfaces in maritime engineering. Of interest here are the long steady waves generated by ships, the gravity waves. In t

  9. Large spiral and target waves: Turbulent diffusion boosts scales of pattern formation

    CERN Document Server

    von Kameke, A; Muñuzuri, A P; Pérez-Muñuzuri, V

    2012-01-01

    In absence of advection, reaction-diffusion systems are able to organize into spatiotemporal patterns, in particular spiral and target waves. Whenever advection is present and can be parameterised in terms of effective or turbulent diffusion $D_{*}$, these patterns should be attainable on much greater, boosted lengthscale. However, so far, experimental evidence of these boosted patterns in turbulent flow was lacking. Here, we report the first experimental observation of boosted target and spiral patterns in an excitable chemical reaction in a quasi two-dimensional turbulent flow. The wave patterns observed are $\\sim 50$ times larger than in the case of molecular diffusion only. We vary the turbulent diffusion coefficient $D_{*}$ of the flow and find that the fundamental Fisher-Kolmogorov-Petrovsky-Piskunov (FKPP) equation $v_{f} \\propto \\sqrt{D_{*}}$ for the asymptotic speed of a reactive wave remains valid. However, not all measures of the boosted wave scale with $D_{*}$ as expected from molecular diffusion,...

  10. Impact of density information on Rayleigh surface wave inversion results

    Science.gov (United States)

    Ivanov, Julian; Tsoflias, Georgios; Miller, Richard D.; Peterie, Shelby; Morton, Sarah; Xia, Jianghai

    2016-12-01

    We assessed the impact of density on the estimation of inverted shear-wave velocity (Vs) using the multi-channel analysis of surface waves (MASW) method. We considered the forward modeling theory, evaluated model sensitivity, and tested the effect of density information on the inversion of seismic data acquired in the Arctic. Theoretical review, numerical modeling and inversion of modeled and real data indicated that the density ratios between layers, not the actual density values, impact the determination of surface-wave phase velocities. Application on real data compared surface-wave inversion results using: a) constant density, the most common approach in practice, b) indirect density estimates derived from refraction compressional-wave velocity observations, and c) from direct density measurements in a borehole. The use of indirect density estimates reduced the final shear-wave velocity (Vs) results typically by 6-7% and the use of densities from a borehole reduced the final Vs estimates by 10-11% compared to those from assumed constant density. In addition to the improved absolute Vs accuracy, the resulting overall Vs changes were unevenly distributed laterally when viewed on a 2-D section leading to an overall Vs model structure that was more representative of the subsurface environment. It was observed that the use of constant density instead of increasing density with depth not only can lead to Vs overestimation but it can also create inaccurate model structures, such as a low-velocity layer. Thus, optimal Vs estimations can be best achieved using field estimates of subsurface density ratios.

  11. THE INFLUENCE OF WAVE PATTERNS AND FREQUENCY ON THERMO-ACOUSTIC COOLING EFFECT

    Directory of Open Access Journals (Sweden)

    CHEN BAIMAN

    2011-06-01

    Full Text Available With the increasing environmental challenges, the search for an environmentally benign cooling technology that has simple and robust architecture continues. Thermo-acoustic refrigeration seems to be a promising candidate to fulfil these requirements. In this study, a simple thermo-acoustic refrigeration system was fabricated and tested. The thermo-acoustic refrigerator consists of acoustic driver (loudspeaker, resonator, stack, vacuum system and testing system. The effect of wave patterns and frequency on thermo-acoustic cooling effect was studied. It was found that a square wave pattern would yield superior cooling effects compared to other wave patterns tested.

  12. Regimes of wave type patterning driven by refractory actin feedback: transition from static polarization to dynamic wave behaviour

    Science.gov (United States)

    Holmes, W. R.; Carlsson, A. E.; Edelstein-Keshet, L.

    2012-08-01

    Patterns of waves, patches, and peaks of actin are observed experimentally in many living cells. Models of this phenomenon have been based on the interplay between filamentous actin (F-actin) and its nucleation promoting factors (NPFs) that activate the Arp2/3 complex. Here we present an alternative biologically-motivated model for F-actin-NPF interaction based on properties of GTPases acting as NPFs. GTPases (such as Cdc42, Rac) are known to promote actin nucleation, and to have active membrane-bound and inactive cytosolic forms. The model is a natural extension of a previous mathematical mini-model of small GTPases that generates static cell polarization. Like other modellers, we assume that F-actin negative feedback shapes the observed patterns by suppressing the trailing edge of NPF-generated wave-fronts, hence localizing the activity spatially. We find that our NPF-actin model generates a rich set of behaviours, spanning a transition from static polarization to single pulses, reflecting waves, wave trains, and oscillations localized at the cell edge. The model is developed with simplicity in mind to investigate the interaction between nucleation promoting factor kinetics and negative feedback. It explains distinct types of pattern initiation mechanisms, and identifies parameter regimes corresponding to distinct behaviours. We show that weak actin feedback yields static patterning, moderate feedback yields dynamical behaviour such as travelling waves, and strong feedback can lead to wave trains or total suppression of patterning. We use a recently introduced nonlinear bifurcation analysis to explore the parameter space of this model and predict its behaviour with simulations validating those results.

  13. Analysis of wave velocity patterns in black cherry trees and its effect on internal decay detection

    Science.gov (United States)

    Guanghui Li; Xiping Wang; Hailin Feng; Jan Wiedenbeck; Robert J. Ross

    2014-01-01

    In this study, we examined stress wave velocity patterns in the cross sections of black cherry trees, developed analytical models of stress wave velocity in sound healthy trees, and then tested the effectiveness of the models as a tool for tree decay diagnosis. Acoustic tomography data of the tree cross sections were collected from 12 black cherry trees at a production...

  14. Astrophysical Prior Information and Gravitational-wave Parameter Estimation

    CERN Document Server

    Pankow, Chris; Perri, Leah; Chase, Eve; Coughlin, Scott; Zevin, Michael; Kalogera, Vassiliki

    2016-01-01

    The detection of electromagnetic counterparts to gravitational waves has great promise for the investigation of many scientific questions. It has long been hoped that in addition to providing extra, non-gravitational information about the sources of these signals, the detection of an electromagnetic signal in conjunction with a gravitational wave could aid in the analysis of the gravitational signal itself. That is, knowledge of the sky location, inclination, and redshift of a binary could break degeneracies between these extrinsic, coordinate-dependent parameters and the physical parameters, such as mass and spin, that are intrinsic to the binary. In this paper, we investigate this issue by assuming a perfect knowledge of extrinsic parameters, and assessing the maximal impact of this knowledge on our ability to extract intrinsic parameters. However, we find only modest improvements in a few parameters --- namely the primary component's spin --- and conclude that, even in the best case, the use of additional ...

  15. Information Geometry of Quantum Entangled Gaussian Wave-Packets

    CERN Document Server

    Kim, D -H; Cafaro, C; Mancini, S

    2011-01-01

    Describing and understanding the essence of quantum entanglement and its connection to dynamical chaos is of great scientific interest. In this work, using information geometric (IG) techniques, we investigate the effects of micro-correlations on the evolution of maximal probability paths on statistical manifolds induced by systems whose microscopic degrees of freedom are Gaussian distributed. We use the statistical manifolds associated with correlated and non-correlated Gaussians to model the scattering induced quantum entanglement of two spinless, structureless, non-relativistic particles, the latter represented by minimum uncertainty Gaussian wave-packets. Knowing that the degree of entanglement is quantified by the purity P of the system, we express the purity for s-wave scattering in terms of the micro-correlation coefficient r - a quantity that parameterizes the correlated microscopic degrees of freedom of the system; thus establishing a connection between entanglement and micro-correlations. Moreover, ...

  16. Extreme physical information and the nonlinear wave equation

    Science.gov (United States)

    Frieden, B. R.

    1995-09-01

    The nonlinear wave equation an be derived from a principle of extreme physical information (EPI) K. This is for a scenario where a probe electron moves through a medium in a weak magnetic field. The field is caused by a probabilistic line current source. Assume that the probability current density S of the electron is approximately constant, and directed parallel to the current source. Both the source probability amplitudes (rho) and the electron probability amplitudes (phi) are unknowns (called 'modes') of the problem. The net physical information K here consists of two components: functional K1[(phi) ] due to modes (phi) and K2[(rho) ] due to modes (rho) , respectively. To form K1[(phi) ], the Fisher information functional I1[(phi) ] for the electron modes is first constructed. This is of a fixed mathematical form. Then, a unitary transformation on (phi) to a physical space is sought that leaves I1 invariant, as form J1. This is, of course, the Fourier transformation, where the transform coordinates are momenta and I1 is essentially the mean-square electron momentum. Information K1[(phi) ] is then defined as (I1 - J1). Information K2 is formed similarly. The total information K is formed as the sum of the two components K1[(phi) ] and K2[(rho) ], by the additivity of Fisher information, and is then extremized in both (phi) and (rho) . Extremizing first in (rho) gives a Taylor series in powers of (phi) n*(phi) n, which is cut off at the quadratic term. Back-substituting this into the total Lagrangian gives one that is quadratic in (phi) n*(phi) n. Now varying (phi) * gives the required cubic wave equation in (phi) .

  17. Information theory in computer vision and pattern recognition

    CERN Document Server

    Escolano, Francisco; Bonev, Boyan

    2009-01-01

    Researchers are bringing information theory elements to the computer vision and pattern recognition (CVPR) arena. Among these elements there are measures (entropy, mutual information), principles (maximum entropy, minimax entropy) and theories (rate distortion theory, method of types). This book explores the latter elements.

  18. Numerical simulation of super-square patterns in Faraday waves

    CERN Document Server

    Kahouadji, L; Tuckerman, L S; Shin, S; Chergui, J; Juric, D

    2015-01-01

    We report the first simulations of the Faraday instability using the full three-dimensional Navier-Stokes equations in domains much larger than the characteristic wavelength of the pattern. We use a massively parallel code based on a hybrid Front-Tracking/Level-set algorithm for Lagrangian tracking of arbitrarily deformable phase interfaces. Simulations performed in rectangular and cylindrical domains yield complex patterns. In particular, a superlattice-like pattern similar to those of [Douady & Fauve, Europhys. Lett. 6, 221-226 (1988); Douady, J. Fluid Mech. 221, 383-409 (1990)] is observed. The pattern consists of the superposition of two square superlattices.

  19. Can weakly nonlinear theory explain Faraday wave patterns near onset?

    CERN Document Server

    Skeldon, A C

    2015-01-01

    The Faraday problem is an important pattern-forming system that provides some middle ground between systems where the initial instability involves just a single mode and in which complexity then results from mode interactions or secondary bifurcations, and cases where a system is highly turbulent and many spatial and temporal modes are excited. It has been a rich source of novel patterns and of theoretical work aimed at understanding how and why such patterns occur. Yet it is particularly challenging to tie theory to experiment: the experiments are difficult to perform; the parameter regime of interest (large box, moderate viscosity) along with the technical difficulties of solving the free boundary Navier--Stokes equations make numerical solution of the problem hard; and the fact that the instabilities result in an entire circle of unstable wavevectors presents considerable theoretical difficulties. In principle, weakly nonlinear theory should be able to predict which patterns are stable near pattern onset. ...

  20. Basilar-membrane interference patterns from multiple internal reflection of cochlear traveling waves.

    Science.gov (United States)

    Shera, Christopher A; Cooper, Nigel P

    2013-04-01

    At low stimulus levels, basilar-membrane (BM) mechanical transfer functions in sensitive cochleae manifest a quasiperiodic rippling pattern in both amplitude and phase. Analysis of the responses of active cochlear models suggests that the rippling is a mechanical interference pattern created by multiple internal reflection within the cochlea. In models, the interference arises when reverse-traveling waves responsible for stimulus-frequency otoacoustic emissions (SFOAEs) reflect off the stapes on their way to the ear canal, launching a secondary forward-traveling wave that combines with the primary wave produced by the stimulus. Frequency-dependent phase differences between the two waves then create the rippling pattern measurable on the BM. Measurements of BM ripples and SFOAEs in individual chinchilla ears demonstrate that the ripples are strongly correlated with the acoustic interference pattern measured in ear-canal pressure, consistent with a common origin involving the generation of SFOAEs. In BM responses to clicks, the ripples appear as temporal fine structure in the response envelope (multiple lobes, waxing and waning). Analysis of the ripple spacing and response phase gradients provides a test for the role of fast- and slow-wave modes of reverse energy propagation within the cochlea. The data indicate that SFOAE delays are consistent with reverse slow-wave propagation but much too long to be explained by fast waves.

  1. Severe summer heat waves over Georgia: trends, patterns and driving forces

    Directory of Open Access Journals (Sweden)

    I. Keggenhoff

    2015-11-01

    Full Text Available During the last 50 years Georgia experienced a rising number of severe summer heat waves causing increasing heat-health impacts. In this study, the 10 most severe heat waves between 1961 and 2010 and recent changes in heat wave characteristics have been detected from 22 homogenized temperature minimum and maximum series using the Excess Heat Factor (EHF. A composite and Canonical Correlation Analysis (CCA have been performed to study summer heat wave patterns and their relationships to the selected predictors: mean Sea Level Pressure (SLP, Geopotential Height at 500 mb (Z500, Sea Surface Temperature (SST, Zonal (u-wind500 and Meridional Wind at 500 mb (v-wind500, Vertical Velocity at 500 mb (O500, Outgoing Longwave Radiation (OLR, Relative Humidity (RH500, Precipitation (RR and Soil Moisture (SM. Most severe heat events during the last 50 years are identified in 2007, 2006 and 1998. Largest significant trend magnitudes for the number, intensity and duration of low and high-impact heat waves have been found during the last 30 years. Significant changes in the heat wave predictors reveal that all relevant surface and atmospheric patterns contributing to heat waves have been intensified between 1961 and 2010. Composite anomalies and CCA patterns provide evidence of a large anticyclonic blocking pattern over the southern Ural Mountains, which attracts warm air masses from the Southwest, enhances subsidence and surface heating, shifts the African Intertropical Convergence Zone (ITCZ northwards, and causes a northward shift of the subtropical jet. Moreover, pronounced precipitation and soil moisture deficiency throughout Georgia contribute to the heat wave formation and persistence over Georgia. Due to different large- to mesoscale circulation patterns and the local terrain, heat wave effects over Eastern Georgia are dominated by subsidence and surface heating, while convective rainfall and cooling are observed in the West.

  2. Long waves over a bi-viscous seabed: transverse patterns

    Directory of Open Access Journals (Sweden)

    J. M. Becker

    2002-01-01

    Full Text Available The coupled interaction of long standing hydrodynamic waves with a deformable non-Newtonian seabed is examined using a two-layer model for which the upper layer fluid is inviscid and the lower layer is bi-viscous. The two-dimensional response of the system to forcing by a predominantly longitudinal (cross-shore standing wave perturbed by a small transverse (along-shore component is determined. With a constant yield stress in the bi-viscous lower layer, there is little amplification of these transverse per-turbations and the model response typically remains quasi-one-dimensional. However, for a bi-viscous layer with a pressure-dependent yield stress (which represents the effect that the seabed deforms less readily under compression and hence renders the rheology history dependent, the initially small transverse motions are amplified in some parameter regimes and two-dimensional, permanent bedforms are formed in the lower layer. This simple dynamical model is, therefore, able to explain the formation of permanent bedforms with significant cross- and along-shore features by predominantly cross-shore standing wave forcing.

  3. Evolution of spiral wave and pattern formation in a vortical polarized electric field

    Institute of Scientific and Technical Information of China (English)

    Ma Jun; Yi Ming; Li Bing-Wei; Li Yan-Long

    2008-01-01

    In this paper, the evolution of the pattern transition induced by the vortical electric field (VEF) is investigated. Firstly, a scheme is suggested to generate the VEF by changing the spatial magnetic field. Secondly, the VEF is imposed on the whole medium, and the evolutions of the spiral wave and the spatiotemporal chaos are investigated by using the numerical simulation. The result confirms that the drift and the breakup of the spiral wave and the new net-like pattern are observed when different polarized fields are imposed on the whole medium respectively. Finally, the pattern transition induced by the polarized field is discussed theoretically.

  4. Parametric Study of Flow Patterns behind the Standing Accretion Shock Wave for Core-Collapse Supernovae

    CERN Document Server

    Iwakami, Wakana; Yamada, Shoichi

    2013-01-01

    The systematic research of flow patterns behind the accretion shock wave is conducted using three-dimensional hydrodynamics simulations for core-collapse supernovae in this study. Changing the accretion rate and neutrino luminosity, the steady solutions of the one-dimensional irrotational accretion flow passing through the spherical shock wave are evolved by imposing a random perturbation with 1% amplitude at the onset of the simulations. Depending on the accretion rate and neutrino luminosity, various flow patterns appear behind the shock wave. We classified them into the three fundamental flow patterns: (1) sloshing motion, (2) spiral motion, (3) multiple high-entropy bubbles, and the two anomalous flow patterns: (4) spiral motion with buoyant bubbles, and (5) spiral motion with pulsating rotational velocity. The sloshing and spiral motions tend to be dominant in the higher accretion rate and lower neutrino luminosity, and the generations of multiple buoyant bubbles tend to prevail in the lower accretion ra...

  5. Energy and Information Transfer Via Coherent Exciton Wave Packets

    Science.gov (United States)

    Zang, Xiaoning

    Electronic excitons are bound electron-hole states that are generated when light interacts with matter. Such excitations typically entangle with phonons and rapidly decohere; the resulting electronic state dynamics become diffusive as a result. However, if the exciton-phonon coupling can be reduced, it may be possible to construct excitonic wave packets that offer a means of efficiently transmitting information and energy. This thesis is a combined theory/computation investigation to design condensed matter systems which support the requisite coherent transport. Under the idealizing assumption that exciton-phonon entanglement could be completely suppressed, the majority of this thesis focuses on the creation and manipulation of exciton wave packets in quasi-one-dimensional systems. While each site could be a silicon quantum dot, the actual implementation focused on organic molecular assemblies for the sake of computational simplicity, ease of experimental implementation, potential for coherent transport, and promise because of reduced structural uncertainty. A laser design was derived to create exciton wave packets with tunable shape and speed. Quantum interference was then exploited to manipulate these packets to block, pass, and even dissociate excitons based on their energies. These developments allow exciton packets to be considered within the arena of quantum information science. The concept of controllable excitonic wave packets was subsequently extended to consider molecular designs that allow photons with orbital angular momentum to be absorbed to create excitons with a quasi-angular momentum of their own. It was shown that a well-defined measure of topological charge is conserved in such light-matter interactions. Significantly, it was also discovered that such molecules allow photon angular momenta to be combined and later emitted. This amounts to a new way of up/down converting photonic angular momentum without relying on nonlinear optical materials. The

  6. Evolution of stationary wave patterns in mesospheric water vapor due to climate change

    Science.gov (United States)

    Demirhan Barı, Deniz; Gabriel, Axel; Sezginer Ünal, Yurdanur

    2016-07-01

    The variability in the observed stationary wave patterns of the mesospheric water vapor (H2O) is investigated using CMIP5 RCP 4.5 and RCP 8.5 projections. The change in the vertical and meridional wave structure at northern mid- and polar latitudes associated to the zonal and meridional eddy heat fluxes is discussed by analyzing the advection of H2O due to residual wind components. The alteration in the characteristics of the stationary wave-1 pattern of the lower mesospheric H2O (up to about 75km) related to change in the projected radiative forcing is observed for the years from 2006 to 2100. Additionally the remarkable effect of the increase in global temperature on the zonal asymmetries in small-scale transient waves and parameterized gravity waves, which largely contribute to the observed stationary wave patterns of H2O in the upper mesosphere, is analyzed. For validation purposes, the derived stratospheric patterns are verified against the eddy heat fluxes and residual advection terms derived from Aura/MLS satellite data between 2004-2010 and the reference period of the CMIP5 MPI dataset (1976-2005) providing confidence in the applied method.

  7. Patterns in Standards and Technologies for Economic Information Systems Interoperability

    Directory of Open Access Journals (Sweden)

    Vasile Irimia

    2012-06-01

    Full Text Available This paper presets results from a review of the current standards used for collaboration between economic information systems, including web services and service oriented architecture, EDI, ebXML framework, RosettaNet framework, cXML, xCBL UBL, BPMN, BPEL, WS-CDL, ASN.1, and others. Standards have a key role in promoting economic information system interoperability, and thus enable collaboration. Analyzing the current standards, technologies and applications used for economic information systems interoperability has revealed a common pattern that runs through all of them. From this pattern we construct a basic model of interoperability around which we relate and judge all standards, technologies and applications for economic information systems interoperability.

  8. Regional Logistics Information Resources Integration Patterns and Countermeasures

    Science.gov (United States)

    Wu, Hui; Shangguan, Xu-ming

    Effective integration of regional logistics information resources can provide collaborative services in information flow, business flow and logistics for regional logistics enterprises, which also can reduce operating costs and improve market responsiveness. First, this paper analyzes the realistic significance on the integration of regional logistics information. Second, this paper brings forward three feasible patterns on the integration of regional logistics information resources, These three models have their own strengths and the scope of application and implementation, which model is selected will depend on the specific business and the regional distribution of enterprises. Last, this paper discusses the related countermeasures on the integration of regional logistics information resources, because the integration of regional logistics information is a systems engineering, when the integration is advancing, the countermeasures should pay close attention to the current needs and long-term development of regional enterprises.

  9. Dynamics of actin waves on patterned substrates: a quantitative analysis of circular dorsal ruffles.

    Directory of Open Access Journals (Sweden)

    Erik Bernitt

    Full Text Available Circular Dorsal Ruffles (CDRs have been known for decades, but the mechanism that organizes these actin waves remains unclear. In this article we systematically analyze the dynamics of CDRs on fibroblasts with respect to characteristics of current models of actin waves. We studied CDRs on heterogeneously shaped cells and on cells that we forced into disk-like morphology. We show that CDRs exhibit phenomena such as periodic cycles of formation, spiral patterns, and mutual wave annihilations that are in accord with an active medium description of CDRs. On cells of controlled morphologies, CDRs exhibit extremely regular patterns of repeated wave formation and propagation, whereas on random-shaped cells the dynamics seem to be dominated by the limited availability of a reactive species. We show that theoretical models of reaction-diffusion type incorporating conserved species capture partially the behavior we observe in our data.

  10. Regulating drift-wave plasma turbulence into spatiotemporal patterns by pinning coupling.

    Science.gov (United States)

    Liu, Panpan; Yang, Lei; Deng, Zhigang; Wang, Xingang

    2011-07-01

    Using the technique of pinning coupling in chaos control, we investigate how the two-dimensional drift-wave plasma turbulence described by the Hasegawa-Mima equation can be regulated into different spatiotemporal patterns. It is shown both analytically and numerically that, depending on the pattern structure of the target, the pinning strength necessary for regulating the turbulence could have a large variation. More specifically, with the increase of the wave number of the target, the critical pinning strength is found to be increased by a power-law scaling. Moreover, in both the transition and transient process of the pinning regulation, the modes of the turbulence are found to be suppressed in a hierarchical fashion, that is, by the sequence of mode wave number. The findings give insight into the dynamics of drift-wave turbulence, as well as indicative to the design of new control techniques for real-world turbulence.

  11. Pattern formation in polymerising actin flocks: spirals, spots and waves without nonlinear chemistry

    CERN Document Server

    Goff, Thomas Le; Marenduzzo, Davide

    2016-01-01

    We propose a model solely based on actin treadmilling and polymerisation which describes many characteristic states of actin wave formation: spots, spirals and travelling waves. In our model, as in experiments on cell recovering motility following actin depolymerisation, we choose an isotropic low density initial condition; polymerisation of actin filaments then raises the density towards the Onsager threshold where they align. We show that this alignment, in turn, destabilizes the isotropic phase and generically induces transient actin spots or spirals as part of the dynamical pathway towards a polarized phase which can either be uniform or consist of a series of actin-wave trains (flocks). Our results uncover a universal route to actin wave formation in the absence of any system specific nonlinear biochemistry, and it may help understand the mechanism underlying the observation of actin spots and waves in vivo. They also suggest a minimal setup to design similar patterns in vitro.

  12. Pattern formation in reaction-diffusion systems: From spiral waves to turbulence

    Science.gov (United States)

    Davidsen, Joern

    2009-05-01

    Almost all systems we encounter in nature possess some sort of form or structure. In many cases, the structures arise from an initially unstructured state without the action of an agent that predetermines the pattern. Such self-organized structures emerge from cooperative interactions among the constituents of the system and often exhibit properties that are distinct from those of their constituent elements or molecules. For example, chemical waves in reaction-diffusion systems are at the core of a huge variety of physical, chemical, and biological processes. In (quasi) two-dimensional situations, spiral wave patterns are especially prevalent and determine the characteristics of processes such as surface catalytic oxidation reactions, contraction of the heart muscle, and various signaling mechanisms in biological systems. In this talk, I will review and discuss recent theoretical and experimental results regarding the dynamics, properties and stability of spiral waves and their three-dimensional analog (scroll waves). Special emphasis will be given to synchronization defect lines which generically arise in complex-oscillatory media, and the phenomenon of defect-mediated turbulence or filament turbulence where the dynamics of a pattern is dominated by the rapid motion, nucleation, and annihilation of spirals or scroll waves, respectively. The latter is of direct relevance in the context of ventricular fibrillation - a turbulent electrical wave activity that destroys the coherent contraction of the ventricular muscle and its main pumping function leading to sudden cardiac death.

  13. Parametrically Excited Surface Waves Two-Frequency Forcing, Normal Form Symmetries, and Pattern Selection

    CERN Document Server

    Silber, M; Silber, Mary; Skeldon, Anne C.

    1999-01-01

    Motivated by experimental observations of exotic standing wave patterns in the two-frequency Faraday experiment, we investigate the role of normal form symmetries in the pattern selection problem. With forcing frequency components in ratio m/n, where m and n are co-prime integers, there is the possibility that both harmonic and subharmonic waves may lose stability simultaneously, each with a different wavenumber. We focus on this situation and compare the case where the harmonic waves have a longer wavelength than the subharmonic waves with the case where the harmonic waves have a shorter wavelength. We show that in the former case a normal form transformation can be used to remove all quadratic terms from the amplitude equations governing the relevant resonant triad interactions. Thus the role of resonant triads in the pattern selection problem is greatly diminished in this situation. We verify our general results within the example of one-dimensional surface wave solutions of the Zhang-Vinals model of the t...

  14. What is the angle of a nonlinear Kelvin ship wave pattern?

    CERN Document Server

    Pethiyagoda, Ravindra; Moroney, Timothy J

    2014-01-01

    While the half-angle which encloses a Kelvin ship wave pattern is commonly accepted to be 19.47 degrees, recent observations and calculations for sufficiently fast-moving ships suggest that the apparent wake angle decreases with ship speed. One explanation for this decrease in angle relies on the assumption that a ship cannot generate wavelengths much greater than its hull length. An alternative interpretation is that the wave pattern that is observed in practice is defined by the location of the highest peaks; for wakes created by sufficiently fast-moving objects, these highest peaks no longer lie on the outermost divergent waves, resulting in a smaller apparent angle. In this paper, we focus on the problem of free surface flow past a submerged point source. In the linear case, we measure the apparent wake angle formed by the highest peaks, and observe the following three regimes: a small Froude number pattern, in which the divergent waves are not visible; standard wave patterns for which the maximum peaks o...

  15. Reconstruction of Interfering Waves from Three Dimensional Analysis of Their Interference Pattern

    Directory of Open Access Journals (Sweden)

    M. T. Tavassoli

    1997-04-01

    Full Text Available   Optical interferometry is being used as an efficient tool to analyse smooth surfaces for more than a century. Although, due to introduction of novel computer assisted analyzing techniques and array detectors, like CCD, the speed and the precision of processing have been increased tremendously, but the main equation involved is not changed. The main equation is the intensity distribution in the interference pattern of a plane reference wave and the required wave.   In the paper it is shown that by analysis of the interference pattern of two unknown waves in three dimension (which is possible for coherent waves it is possible to reconstruct each wave separately. This approach has several useful applications, namely, on can do without reference plane wave in the interferometric surface analysis and, it is possible to reconstruct an unknown wave by making it to interfere with itself. This is very useful in determining the profile of laser beams and erasing the effect of atmospheric disturbances on observing astronomical objects.

  16. Electromagnetic Wave Absorbing Composites with a Square Patterned Conducting Polymer Layer for Wideband Characteristics

    Directory of Open Access Journals (Sweden)

    Won-Jun Lee

    2014-01-01

    Full Text Available The applications of electromagnetic- (EM- wave-absorbers are being expanded for commercial and military purposes. For military applications in particular, EM-wave-absorbers (EMWAs could minimize Radar Cross Section (RCS of structures, which could reduce the possibility of detection by radar. In this study, EMWA composite structure containing a square periodic patterned layer is presented. It was found that control of the pattern geometry and surface resistance induced EMWA characteristics which can create multiresonance for wideband absorption in composite structures.

  17. A dispersive wave pattern on Jupiter's fastest retrograde jet at 20°S

    Science.gov (United States)

    Rogers, J. H.; Fletcher, L. N.; Adamoli, G.; Jacquesson, M.; Vedovato, M.; Orton, G. S.

    2016-10-01

    A compact wave pattern has been identified on Jupiter's fastest retrograding jet at 20°S (the SEBs) on the southern edge of the South Equatorial Belt. The wave has been identified in both reflected sunlight from amateur observations between 2010 and 2015, thermal infrared imaging from the Very Large Telescope and near infrared imaging from the Infrared Telescope Facility. The wave pattern is present when the SEB is relatively quiescent and lacking large-scale disturbances, and is particularly notable when the belt has undergone a fade (whitening). It is generally not present when the SEB exhibits its usual large-scale convective activity ('rifts'). Tracking of the wave pattern and associated white ovals on its southern edge over several epochs have permitted a measure of the dispersion relationship, showing a strong correlation between the phase speed (-43.2 to -21.2 m/s) and the longitudinal wavelength, which varied from 4.4 to 10.0° longitude over the course of the observations. Infrared imaging sensing low pressures in the upper troposphere suggest that the wave is confined to near the cloud tops. The wave is moving westward at a phase speed slower (i.e., less negative) than the peak retrograde wind speed (-62 m/s), and is therefore moving east with respect to the SEBs jet peak. Unlike the retrograde NEBn jet near °N, which is a location of strong vertical wind shear that sometimes hosts Rossby wave activity, the SEBs jet remains retrograde throughout the upper troposphere, suggesting the SEBs pattern cannot be interpreted as a classical Rossby wave. 2D windspeeds and thermal gradients measured by Cassini in 2000 are used to estimate the quasi-geostrophic potential vorticity gradient as a means of understanding the origin of the a wave. We find that the vorticity gradient is dominated by the baroclinic term and becomes negative (changes sign) in a region near the cloud-top level (400-700 mbar) associated with the SEBs. Such a sign reversal is a necessary (but

  18. Symmetry-induced pinning-depinning transition of a subharmonic wave pattern.

    Science.gov (United States)

    Garay, Jeremías; Ortega, Ignacio; Clerc, Marcel G; Falcón, Claudio

    2012-03-01

    The stationary to drifting transition of a subharmonic wave pattern is studied in the presence of inhomogeneities and drift forces as the pattern wavelength is comparable with the system size. We consider a pinning-depinning transition of stationary subharmonic waves in a tilted quasi-one-dimensional fluidized shallow granular bed driven by a periodic air flow in a small cell. The transition is mediated by the competition of the inherent periodicity of the subharmonic pattern, the asymmetry of the system, and the finite size of the cell. Measurements of the mean phase velocity of the subharmonic pattern are in good agreement with those inferred from an amplitude equation, which takes into account asymmetry and finite-size effects of the system, emphasizing the main ingredients and mechanism of the transition.

  19. Transient structures of wave patterns arising in the wave regeneration of subalpine coniferous forests

    Science.gov (United States)

    Ichinose, Shin-Ichi

    2001-12-01

    In wave-regeneration phenomena observed in the subalpine coniferous forests, mainly consisting of Abies species, the blighted forests present various shapes in the course of development, spots at the initial stage turning into arches and finally into long whitish stripes. Because the wave-regeneration could not be followed in the field without long term studies, a simple model has been elaborated to simulate the various different dieback structures observed in the real forests. This model, based on cellular automata, is employed to analyze the power spectral density of canopy tree height fluctuations in the wave-regenerated forests. The results demonstrate that almost all the dieback structures observed in the field can be generated by this simple model, by varying the wind direction and its strength by some stochasticity. The power spectrum density presents various shapes in the course of development, white noise type at the initial stage turning into Lorentz type and finally into 1/f type power spectrum (spatial Fourier frequency).

  20. Moving waves and spatiotemporal patterns due to weak thermal effects in models of catalytic oxidation

    Science.gov (United States)

    Nekhamkina, Olga; Sheintuch, Moshe

    2005-05-01

    We analyze the behavior of a microkinetic model of a catalytic reaction coupled with weak enthalpy effects to show that under fixed gas-phase concentrations it can produce moving waves with an intrinsic length scale, when the underlying kinetics is oscillatory. The kinetic model incorporates dissociative oxygen adsorption, reactant adsorption and desorption, and surface reaction. Three typical patterns may emerge in a one-dimensional system (a long wire or a ring): homogeneous oscillations, a family of moving waves propagating with constant velocities, and patterns with multiple source/sink points. Pattern selection depends on the ratio of the system length to the intrinsic wave length and the governing parameters. We complement these analysis with simulations that revealed a plethora of patterned states on one- and two-dimensional systems (a disk or a cylinder). This work shows that weak long-range coupling due to high feed rates maintains such patterns, while low feed rates or strong long-range interaction can gradually suppress the emerging patterns.

  1. Incomplete photonic band gap as inferred from the speckle pattern of scattered light waves.

    Science.gov (United States)

    Apalkov, V M; Raikh, M E; Shapiro, B

    2004-06-25

    Motivated by recent experiments on intensity correlations of the waves transmitted through disordered media, we demonstrate that the speckle pattern from disordered photonic crystal with incomplete band gap represents a sensitive tool for determination of the stop-band width. We establish the quantitative relation between this width and the angular anisotropy of the intensity correlation function.

  2. Different Brain Wave Patterns and Cortical Control Abilities in Relation to Different Creative Potentials

    Science.gov (United States)

    Li, Ying-Han; Tseng, Chao-Yuan; Tsai, Arthur Chih-Hsin; Huang, Andrew Chih-Wei; Lin, Wei-Lun

    2016-01-01

    Contemporary understanding of brain functions provides a way to probe into the mystery of creativity. However, the prior evidence regarding the relationship between creativity and brain wave patterns reveals inconsistent conclusions. One possible reason might be that the means of selecting creative individuals in the past has varied in each study.…

  3. Word Sense Disambiguation Based on Mutual Information and Syntactic Patterns

    CERN Document Server

    Fernandez-Amoros, David

    2009-01-01

    This paper describes a hybrid system for WSD, presented to the English all-words and lexical-sample tasks, that relies on two different unsupervised approaches. The first one selects the senses according to mutual information proximity between a context word a variant of the sense. The second heuristic analyzes the examples of use in the glosses of the senses so that simple syntactic patterns are inferred. This patterns are matched against the disambiguation contexts. We show that the first heuristic obtains a precision and recall of .58 and .35 respectively in the all words task while the second obtains .80 and .25. The high precision obtained recommends deeper research of the techniques. Results for the lexical sample task are also provided.

  4. Magnetization reversal mechanism in patterned (square to wave-like) Py antidot lattices

    Science.gov (United States)

    Tahir, N.; Zelent, M.; Gieniusz, R.; Krawczyk, M.; Maziewski, A.; Wojciechowski, T.; Ding, J.; Adeyeye, A. O.

    2017-01-01

    The effects of shape and geometry of antidot (square, bi-component, and wave-like) lattices (ADLs) on the magnetization reversal processes and magnetic anisotropy has been systematically investigated by magneto-optical Kerr effect based microscopy. Our experimental results were reproduced by micromagnetic simulations, which highlight the qualitative agreement with the experimental results. We have demonstrated that a small antidot in the center of a unit cell in the square ADL is sufficient to induce additional easy axes with large coercive fields. In wave-like patterns, narrow channels connecting smaller and larger antidots (bi-component ADL) further drastically change the anisotropy map, creating the high coercive fields along a wide angular range (90°) of directions parallel to the channels. In simulated results, we have observed formation of periodic domain structures in all ADLs, however, in the case of a wave-like pattern it is most regular and moreover two different periodic patterns are stabilized at different applied magnetic field values. The formation of 360° domain walls were also observed in wave-like ADL where these domains are formed along the lines connecting adjacent larger and smaller antidots, perpendicular to the channels. These findings point out the possibility of exploiting ADLs with complex unit cells in magnonic or spintronic applications.

  5. Prediction of ion-exchange column breakthrough curves by constant-pattern wave approach.

    Science.gov (United States)

    Lee, I-Hsien; Kuan, Yu-Chung; Chern, Jia-Ming

    2008-03-21

    The release of heavy metals from industrial wastewaters represents one of major threats to environment. Compared with chemical precipitation method, fixed-bed ion-exchange process can effectively remove heavy metals from wastewaters and generate no hazardous sludge. In order to design and operate fixed-bed ion-exchange processes successfully, it is very important to understand the column dynamics. In this study, the column experiments for Cu2+/H+, Zn2+/H+, and Cd2+/H+ systems using Amberlite IR-120 were performed to measure the breakthrough curves under varying operating conditions. The experimental results showed that total cation concentration in the mobile-phase played a key role on the breakthrough curves; a higher feed concentration resulted in an earlier breakthrough. Furthermore, the column dynamics was also predicted by self-sharpening and constant-pattern wave models. The self-sharpening wave model assuming local ion-exchange equilibrium could provide a simple and quick estimation for the breakthrough volume, but the predicted breakthrough curves did not match the experimental data very well. On the contrary, the constant-pattern wave model using a constant driving force model for finite ion-exchange rate provided a better fit to the experimental data. The obtained liquid-phase mass transfer coefficient was correlated to the flow velocity and other operating parameters; the breakthrough curves under varying operating conditions could thus be predicted by the constant-pattern wave model using the correlation.

  6. Calcium spikes, waves and oscillations in a large, patterned epithelial tissue.

    Science.gov (United States)

    Balaji, Ramya; Bielmeier, Christina; Harz, Hartmann; Bates, Jack; Stadler, Cornelia; Hildebrand, Alexander; Classen, Anne-Kathrin

    2017-02-20

    While calcium signaling in excitable cells, such as muscle or neurons, is extensively characterized, calcium signaling in epithelial tissues is little understood. Specifically, the range of intercellular calcium signaling patterns elicited by tightly coupled epithelial cells and their function in the regulation of epithelial characteristics are little explored. We found that in Drosophila imaginal discs, a widely studied epithelial model organ, complex spatiotemporal calcium dynamics occur. We describe patterns that include intercellular waves traversing large tissue domains in striking oscillatory patterns as well as spikes confined to local domains of neighboring cells. The spatiotemporal characteristics of intercellular waves and oscillations arise as emergent properties of calcium mobilization within a sheet of gap-junction coupled cells and are influenced by cell size and environmental history. While the in vivo function of spikes, waves and oscillations requires further characterization, our genetic experiments suggest that core calcium signaling components guide actomyosin organization. Our study thus suggests a possible role for calcium signaling in epithelia but importantly, introduces a model epithelium enabling the dissection of cellular mechanisms supporting the initiation, transmission and regeneration of long-range intercellular calcium waves and the emergence of oscillations in a highly coupled multicellular sheet.

  7. A dispersive wave pattern on Jupiter's fastest retrograde jet at $20^\\circ$S

    CERN Document Server

    Rogers, J H; Adamoli, G; Jacquesson, M; Vedovato, M; Orton, G S

    2016-01-01

    A compact wave pattern has been identified on Jupiter's fastest retrograding jet at 20S (the SEBs) on the southern edge of the South Equatorial Belt. The wave has been identified in both reflected sunlight from amateur observations between 2010 and 2015, thermal infrared imaging from the Very Large Telescope and near infrared imaging from the Infrared Telescope Facility. The wave pattern is present when the SEB is relatively quiescent and lacking large-scale disturbances, and is particularly notable when the belt has undergone a fade (whitening). It is generally not present when the SEB exhibits its usual large-scale convective activity ('rifts'). Tracking of the wave pattern and associated white ovals on its southern edge over several epochs have permitted a measure of the dispersion relationship, showing a strong correlation between the phase speed (-43.2 to -21.2 m/s) and the longitudinal wavelength, which varied from 4.4-10.0 deg. longitude over the course of the observations. Infrared imaging sensing low...

  8. Calcium spikes, waves and oscillations in a large, patterned epithelial tissue

    Science.gov (United States)

    Balaji, Ramya; Bielmeier, Christina; Harz, Hartmann; Bates, Jack; Stadler, Cornelia; Hildebrand, Alexander; Classen, Anne-Kathrin

    2017-01-01

    While calcium signaling in excitable cells, such as muscle or neurons, is extensively characterized, calcium signaling in epithelial tissues is little understood. Specifically, the range of intercellular calcium signaling patterns elicited by tightly coupled epithelial cells and their function in the regulation of epithelial characteristics are little explored. We found that in Drosophila imaginal discs, a widely studied epithelial model organ, complex spatiotemporal calcium dynamics occur. We describe patterns that include intercellular waves traversing large tissue domains in striking oscillatory patterns as well as spikes confined to local domains of neighboring cells. The spatiotemporal characteristics of intercellular waves and oscillations arise as emergent properties of calcium mobilization within a sheet of gap-junction coupled cells and are influenced by cell size and environmental history. While the in vivo function of spikes, waves and oscillations requires further characterization, our genetic experiments suggest that core calcium signaling components guide actomyosin organization. Our study thus suggests a possible role for calcium signaling in epithelia but importantly, introduces a model epithelium enabling the dissection of cellular mechanisms supporting the initiation, transmission and regeneration of long-range intercellular calcium waves and the emergence of oscillations in a highly coupled multicellular sheet. PMID:28218282

  9. Ethical Dilemmas in Applying Second-Wave Information Technology to Social Work Practice.

    Science.gov (United States)

    Cwikel, Julie G.; Cnaan, Ram A.

    1991-01-01

    Describes second wave information technology in social work as characterized by modern databases, decision-support systems, expert systems, electronic networks, and therapeutic applications that have greater impact on direct practice. Assesses ethical dilemmas posed by use of second-wave information technology in social work practice to encourage…

  10. The patterns of surface capillary-gravity short-crested waves with uniform current fields in coastal waters

    Institute of Scientific and Technical Information of China (English)

    Hu Huang; Jia Fu

    2006-01-01

    A fully three-dimensional surface gravitycapillary short-crested wave system is studied as two progressive wave-trains of equal amplitude and frequency, which are collinear with uniform currents and doubly-periodic in the horizontal plane, are propagating at an angle to each other. The first-and second-order asymptotic analytical solutions of the short-crested wave system are obtained via a perturbation expansion in a small parameter associated with the wave steepness, therefore depicting a series of typical three-dimensional wave patterns involving currents, shallow and deep water, and surface capillary waves, and comparing them with each other.

  11. A Scanned Perturbation Technique For Imaging Electromagnetic Standing Wave Patterns of Microwave Cavities

    CERN Document Server

    Gokirmak, A; Bridgewater, A; Anlage, S M; Gokirmak, Ali; Wu, Dong-Ho; Anlage, Steven M.

    1998-01-01

    We have developed a method to measure the electric field standing wave distributions in a microwave resonator using a scanned perturbation technique. Fast and reliable solutions to the Helmholtz equation (and to the Schrodinger equation for two dimensional systems) with arbitrarily-shaped boundaries are obtained. We use a pin perturbation to image primarily the microwave electric field amplitude, and we demonstrate the ability to image broken time-reversal symmetry standing wave patterns produced with a magnetized ferrite in the cavity. The whole cavity, including areas very close to the walls, can be imaged using this technique with high spatial resolution over a broad range of frequencies.

  12. Frequency and distance changes in the apparent P-wave radiation pattern: effects of seismic wave scattering in the crust inferred from dense seismic observations and numerical simulations

    Science.gov (United States)

    Kobayashi, Manabu; Takemura, Shunsuke; Yoshimoto, Kazuo

    2015-09-01

    Frequency and distance changes in the apparent P-wave radiation pattern (0.75-12 Hz) are investigated using velocity seismograms of shallow strike-slip earthquakes occurring in Chugoku region, southwestern Japan. Data from a dense seismic monitoring network revealed that the four-lobe apparent P-wave radiation pattern was gradually distorted with increasing frequency and propagation distance. Observed features suggest that seismic wave scattering due to small-scale velocity heterogeneity in the crust may be a major cause of this distortion. The effects of seismic wave scattering on apparent P-wave radiation pattern were investigated via 3-D finite difference simulation of seismic wave propagation. Our simulations demonstrated that the scattering of seismic waves modified the apparent P-wave radiation pattern from the original four-lobe shape, and that the small-scale velocity heterogeneity, characterized by the von Kármán-type power spectral density function with correlation distance of 1 km, root-mean-square value of 0.03 and decay rate parameter of 0.5, might be adequate for modelling crustal heterogeneity in the target region. It was also found that the scattering attenuation of P wave expected from this heterogeneity is significantly smaller than the apparent P-wave attenuation and S-wave scattering attenuation reported by Multiple Lapse Time Window Analysis of previous studies in Japan. These results might imply that scattering attenuation is not the dominant mechanism of P-wave attenuation in the crust of Chugoku region.

  13. Refinement and Pattern Formation in Neural Circuits by the Interaction of Traveling Waves with Spike-Timing Dependent Plasticity

    Science.gov (United States)

    Bennett, James E. M.; Bair, Wyeth

    2015-01-01

    Traveling waves in the developing brain are a prominent source of highly correlated spiking activity that may instruct the refinement of neural circuits. A candidate mechanism for mediating such refinement is spike-timing dependent plasticity (STDP), which translates correlated activity patterns into changes in synaptic strength. To assess the potential of these phenomena to build useful structure in developing neural circuits, we examined the interaction of wave activity with STDP rules in simple, biologically plausible models of spiking neurons. We derive an expression for the synaptic strength dynamics showing that, by mapping the time dependence of STDP into spatial interactions, traveling waves can build periodic synaptic connectivity patterns into feedforward circuits with a broad class of experimentally observed STDP rules. The spatial scale of the connectivity patterns increases with wave speed and STDP time constants. We verify these results with simulations and demonstrate their robustness to likely sources of noise. We show how this pattern formation ability, which is analogous to solutions of reaction-diffusion systems that have been widely applied to biological pattern formation, can be harnessed to instruct the refinement of postsynaptic receptive fields. Our results hold for rich, complex wave patterns in two dimensions and over several orders of magnitude in wave speeds and STDP time constants, and they provide predictions that can be tested under existing experimental paradigms. Our model generalizes across brain areas and STDP rules, allowing broad application to the ubiquitous occurrence of traveling waves and to wave-like activity patterns induced by moving stimuli. PMID:26308406

  14. Extracting information in spike time patterns with wavelets and information theory.

    Science.gov (United States)

    Lopes-dos-Santos, Vítor; Panzeri, Stefano; Kayser, Christoph; Diamond, Mathew E; Quian Quiroga, Rodrigo

    2015-02-01

    We present a new method to assess the information carried by temporal patterns in spike trains. The method first performs a wavelet decomposition of the spike trains, then uses Shannon information to select a subset of coefficients carrying information, and finally assesses timing information in terms of decoding performance: the ability to identify the presented stimuli from spike train patterns. We show that the method allows: 1) a robust assessment of the information carried by spike time patterns even when this is distributed across multiple time scales and time points; 2) an effective denoising of the raster plots that improves the estimate of stimulus tuning of spike trains; and 3) an assessment of the information carried by temporally coordinated spikes across neurons. Using simulated data, we demonstrate that the Wavelet-Information (WI) method performs better and is more robust to spike time-jitter, background noise, and sample size than well-established approaches, such as principal component analysis, direct estimates of information from digitized spike trains, or a metric-based method. Furthermore, when applied to real spike trains from monkey auditory cortex and from rat barrel cortex, the WI method allows extracting larger amounts of spike timing information. Importantly, the fact that the WI method incorporates multiple time scales makes it robust to the choice of partly arbitrary parameters such as temporal resolution, response window length, number of response features considered, and the number of available trials. These results highlight the potential of the proposed method for accurate and objective assessments of how spike timing encodes information. Copyright © 2015 the American Physiological Society.

  15. Third-dimension information retrieval from a single convergent-beam transmission electron diffraction pattern using an artificial neural network

    Science.gov (United States)

    Pennington, Robert S.; Van den Broek, Wouter; Koch, Christoph T.

    2014-05-01

    We have reconstructed third-dimension specimen information from convergent-beam electron diffraction (CBED) patterns simulated using the stacked-Bloch-wave method. By reformulating the stacked-Bloch-wave formalism as an artificial neural network and optimizing with resilient back propagation, we demonstrate specimen orientation reconstructions with depth resolutions down to 5 nm. To show our algorithm's ability to analyze realistic data, we also discuss and demonstrate our algorithm reconstructing from noisy data and using a limited number of CBED disks. Applicability of this reconstruction algorithm to other specimen parameters is discussed.

  16. Postprocessing for character recognition using pattern features and linguistic information

    Science.gov (United States)

    Yoshikawa, Takatoshi; Okamoto, Masayosi; Horii, Hiroshi

    1993-04-01

    We propose a new method of post-processing for character recognition using pattern features and linguistic information. This method corrects errors in the recognition of handwritten Japanese sentences containing Kanji characters. This post-process method is characterized by having two types of character recognition. Improving the accuracy of the character recognition rate of Japanese characters is made difficult by the large number of characters, and the existence of characters with similar patterns. Therefore, it is not practical for a character recognition system to recognize all characters in detail. First, this post-processing method generates a candidate character table by recognizing the simplest features of characters. Then, it selects words corresponding to the character from the candidate character table by referring to a word and grammar dictionary before selecting suitable words. If the correct character is included in the candidate character table, this process can correct an error, however, if the character is not included, it cannot correct an error. Therefore, if this method can presume a character does not exist in a candidate character table by using linguistic information (word and grammar dictionary). It then can verify a presumed character by character recognition using complex features. When this method is applied to an online character recognition system, the accuracy of character recognition improves 93.5% to 94.7%. This proved to be the case when it was used for the editorials of a Japanese newspaper (Asahi Shinbun).

  17. Adaptive defect and pattern detection in amplitude and phase structures via photorefractive four-wave mixing.

    Science.gov (United States)

    Nehmetallah, George; Banerjee, Partha; Khoury, Jed

    2015-11-10

    This work comprises the theoretical and numerical validations of experimental work on pattern and defect detection of periodic amplitude and phase structures using four-wave mixing in photorefractive materials. The four-wave mixing optical processor uses intensity filtering in the Fourier domain. Specifically, the nonlinear transfer function describing four-wave mixing is modeled, and the theory for detection of amplitude and phase defects and dislocations are developed. Furthermore, numerical simulations are performed for these cases. The results show that this technique successfully detects the slightest defects clearly even with no prior enhancement. This technique should prove to be useful in quality control systems, production-line defect inspection, and e-beam lithography.

  18. A multivariate extreme wave and storm surge climate emulator based on weather patterns

    Science.gov (United States)

    Rueda, A.; Camus, P.; Tomás, A.; Vitousek, S.; Méndez, F. J.

    2016-08-01

    Coastal floods often coincide with large waves, storm surge and tides. Thus, joint probability methods are needed to properly characterize extreme sea levels. This work introduces a statistical downscaling framework for multivariate extremes that relates the non-stationary behavior of coastal flooding events to the occurrence probability of daily weather patterns. The proposed method is based on recently-developed weather-type methods to predict extreme events (e.g., significant wave height, mean wave period, surge level) from large-scale sea-level pressure fields. For each weather type, variables of interest are modeled using Generalized Extreme Value (GEV) distributions and a Gaussian copula for modelling the interdependence between variables. The statistical dependence between consecutive days is addressed by defining a climate-based extremal index for each weather type. This work allows attribution of extreme events to specific weather conditions, enhancing the knowledge of climate-driven coastal flooding.

  19. "Giant R wave" electrocardiogram pattern during exercise treadmill test: A case report

    Directory of Open Access Journals (Sweden)

    Puebla-Rojo Victor

    2011-07-01

    Full Text Available Abstract Introduction The exercise treadmill test is widely used in the evaluation of patients with suspected or known coronary artery disease. The typical ischemic response used to be ST-segment depression. Case presentation We describe a case of a 51-year-old Caucasian man with an unusual ischemic response during the exercise treadmill test: a "giant R wave" electrocardiogram pattern as a manifestation of hyperacute ischemia that resolved with sublingual nitroglycerin. Coronary catheterization showed a severe stenosis in a proximal dominant circumflex coronary artery. We hypothesize that, in this case, the "giant R wave" pattern was related to severe hyperacute ischemia due to coronary spasm superimposed on the atherosclerotic lesion, which probably caused complete occlusion of the artery. The patient was successfully treated with coronary percutaneous revascularization. Conclusions This is a dramatic and rare ischemic response during the exercise treadmill test, in which, a rapid administration of nitroglycerin can prevent life-threatening events.

  20. Satellite altimetry reveals spatial patterns of variations in the Baltic Sea wave climate

    Science.gov (United States)

    Kudryavtseva, Nadezhda; Soomere, Tarmo

    2017-08-01

    The main properties of the climate of waves in the seasonally ice-covered Baltic Sea and its decadal changes since 1990 are estimated from satellite altimetry data. The data set of significant wave heights (SWHs) from all existing nine satellites, cleaned and cross-validated against in situ measurements, shows overall a very consistent picture. A comparison with visual observations shows a good correspondence with correlation coefficients of 0.6-0.8. The annual mean SWH reveals a tentative increase of 0.005 m yr-1, but higher quantiles behave in a cyclic manner with a timescale of 10-15 years. Changes in the basin-wide average SWH have a strong meridional pattern: an increase in the central and western parts of the sea and a decrease in the east. This pattern is likely caused by a rotation of wind directions rather than by an increase in the wind speed.

  1. Nexus between directionality of THz waves and structural parameters in groove-patterned InAs

    CERN Document Server

    Yim, Jong-Hyuk; Jeong, Hoonil; Song, Jin-Dong; Jho, Young-Dahl

    2012-01-01

    We have performed terahertz (THz)-time domain spectroscopy in various geometries, for characterizing the directivity of THz waves emitted from groove-patterned InAs structures. First, we have distinguished the THz emission mechanisms as a function of epilayer thickness. The carrier drift was predominant in thin sample group (10-70 nm) which the electronic diffusion motion was overriding the oppositely aligned drifting dipoles in thick sample group (370-900 nm) as revealed via amplitude and phase variations. By combined use of the electron-beam lithography and the inductively coupled plasma etching in 1 {\\mu}m-thick InAs epilayers, we have further fabricated either asymmetric V-groove patterns or symmetric parabolic patterns. The THz amplitude was enhanced, particularly along line-of-sight transmissive direction when the groove patterns act as microscale reflective mirrors periodically separated by a scale of diffusion length.

  2. Analysis and correction of ocean wave pattern induced systematic coordinate errors in airborne LiDAR bathymetry

    Science.gov (United States)

    Westfeld, Patrick; Maas, Hans-Gerd; Richter, Katja; Weiß, Robert

    2017-06-01

    This contribution investigates the effects of ocean wave patterns on 3D underwater point coordinate accuracy for LiDAR bathymetry. The refraction of the finite diameter laser pulse passing the air/water interface is modeled differentially in a strict manner. Typical wave patterns and sensor configurations are simulated, and their impact on the 3D coordinates at the bottom of the water body are systematically analyzed. It can be shown that waves have a significant effect on both the planimetry and depth coordinates of underwater topography 3D point cloud coordinates, especially for modern small footprint LiDAR systems. Planimetric effects may reach several decimeters or even meters, and depth coordinate errors also reach several decimeters, even in the case of a horizontal water body bottom. The simulations show that the simplified assumption, that wave effects average out (as is made in most LiDAR bathymetry data processing tools) is not even fulfilled for large footprint systems (spreading the laser beam to a diameter of several meters at the water surface) under certain wave pattern conditions. Modern systems with smaller beam divergence are much more sensitive to wave-induced variations of the refraction conditions and will experience significant wave pattern dependent coordinate errors. The results presented here form a basis for a more strict coordinate correction, if the wave pattern can be modeled from the LiDAR bathymetry water surface reflections or from other observations. Moreover, it will be shown that the induced coordinate errors contain a non-zero bias in addition to a local wave surface dependent quasi-random part, which allows for the formulation of wave pattern dependent correction terms in order to increase the accuracy of LiDAR bathymetry by removing systematic wave pattern dependent effects.

  3. Self-Organization of Embryonic Genetic Oscillators into Spatiotemporal Wave Patterns

    Science.gov (United States)

    Tsiairis, Charisios D.; Aulehla, Alexander

    2016-01-01

    Summary In vertebrate embryos, somites, the precursor of vertebrae, form from the presomitic mesoderm (PSM), which is composed of cells displaying signaling oscillations. Cellular oscillatory activity leads to periodic wave patterns in the PSM. Here, we address the origin of such complex wave patterns. We employed an in vitro randomization and real-time imaging strategy to probe for the ability of cells to generate order from disorder. We found that, after randomization, PSM cells self-organized into several miniature emergent PSM structures (ePSM). Our results show an ordered macroscopic spatial arrangement of ePSM with evidence of an intrinsic length scale. Furthermore, cells actively synchronize oscillations in a Notch-signaling-dependent manner, re-establishing wave-like patterns of gene activity. We demonstrate that PSM cells self-organize by tuning oscillation dynamics in response to surrounding cells, leading to collective synchronization with an average frequency. These findings reveal emergent properties within an ensemble of coupled genetic oscillators. PMID:26871631

  4. Cell therapy for spinal cord injury informed by electromagnetic waves.

    Science.gov (United States)

    Finnegan, Jack; Ye, Hui

    2016-10-01

    Spinal cord injury devastates the CNS, besetting patients with symptoms including but not limited to: paralysis, autonomic nervous dysfunction, pain disorders and depression. Despite the identification of several molecular and genetic factors, a reliable regenerative therapy has yet to be produced for this terminal disease. Perhaps the missing piece of this puzzle will be discovered within endogenous electrotactic cellular behaviors. Neurons and stem cells both show mediated responses (growth rate, migration, differentiation) to electromagnetic waves, including direct current electric fields. This review analyzes the pathophysiology of spinal cord injury, the rationale for regenerative cell therapy and the evidence for directing cell therapy via electromagnetic waves shown by in vitro experiments.

  5. Obtaining supernova directional information using the neutrino matter oscillation pattern

    CERN Document Server

    Scholberg, Kate; Wendell, Roger

    2009-01-01

    A nearby core collapse supernova will produce a burst of neutrinos in several detectors worldwide. With reasonably high probability, the Earth will shadow the neutrino flux in one or more detectors. In such a case, for allowed oscillation parameter scenarios, the observed neutrino energy spectrum will bear the signature of oscillations in Earth matter. Because the frequency of the oscillations in energy depends on the pathlength traveled by the neutrinos in the Earth, an observed spectrum contains also information about the direction to the supernova. We explore here the possibility of constraining the supernova location using matter oscillation patterns observed in a detector. Good energy resolution (typical of scintillator detectors), well known oscillation parameters, and optimistically large (but conceivable) statistics are required. Pointing by this method can be significantly improved using multiple detectors located around the globe. Although it is not competitive with neutrino-electron elastic scatter...

  6. Sand wave migration predictor based on shape information

    NARCIS (Netherlands)

    Knaapen, M.A.F.

    2005-01-01

    [1] Migration of offshore seabed waves, which endangers the stability of pipelines and communication cables, is hard to measure. The migration rates are small compared to the measurement errors. Here, sandwave migration rates are determined from the change in the crest position deduced from long tim

  7. Circulation patterns and wave climate along the coast of the Iberian Peninsula

    Science.gov (United States)

    Rasilla Álvarez, D.; García Codrán, J. C.

    2010-09-01

    Evidences of an active erosion (beach retreat, falling cliffs, damaged infrastructures) are observed in many coastal areas around the Iberian Peninsula. Morphogenetic coastal processes result from individual episodes of storminess that can accelerate or mitigate the expected impacts of the global rising trend of average sea levels. Thus, a good understanding of the local forcing processes is required in order to assess the impacts of future sea levels. The spatial and temporal variability of the wave climate along the cost of the Iberian Peninsula and their relationships with regional scale circulation patterns and local-scale winds are the main objectives of this contribution. The oceanographic data set consists of observed hourly data from 7 buoys disseminated along the Spanish coastline, and hindcasted 3-hourly analogous parameters (SIMAR 44 database), provided by Puertos del Estado. Sea level pressure, surface 10m U and V wind components gridded data were obtained from NCEP Reanalysis, while storm tracks and cyclone statistics were extracted from the CDC Map Room Climate Products Storm Track Data (http://www.cdc.noaa.gov/map/clim/st_data.html). The influence of the local conditions was highlighted comparing meteorological data from the buoys and synop reports from coastal stations. To explore the regional atmospheric mechanisms responsible for the wave variability, a regional Eulerian approach (a synoptic typing) were combined with a larger-scale Lagrangian method, based on the analysis of storm-tracks over the area. The synoptic catalogue was obtained following a well-known procedure that combines Principal Component Analysis (PCA) for reduction purposes and clustering (Ward plus K-means) to define the circulation types. As expected, rougher wave climate are observed along the northern and western coast of the Iberian Peninsula, open to the Atlantic storms. The Mediterranean shorelines experiences calmer conditions, although the Gulf of Lions, Catalonian coast

  8. Theoretical analysis of the magnetocardiographic pattern for reentry wave propagation in a three-dimensional human heart model.

    Science.gov (United States)

    Im, Uk Bin; Kwon, Soon Sung; Kim, Kiwoong; Lee, Yong Ho; Park, Yong Ki; Youn, Chan Hyun; Shim, Eun Bo

    2008-01-01

    We present a computational study of reentry wave propagation using electrophysiological models of human cardiac cells and the associated magnetic field map of a human heart. We examined the details of magnetic field variation and related physiological parameters for reentry waves in two-dimensional (2-D) human atrial tissue and a three-dimensional (3-D) human ventricle model. A 3-D mesh system representing the human ventricle was reconstructed from the surface geometry of a human heart. We used existing human cardiac cell models to simulate action potential (AP) propagation in atrial tissue and 3-D ventricular geometry, and a finite element method and the Galerkin approximation to discretize the 3-D domain spatially. The reentry wave was generated using an S1-S2 protocol. The calculations of the magnetic field pattern assumed a horizontally layered conductor for reentry wave propagation in the 3-D ventricle. We also compared the AP and magnetocardiograph (MCG) magnitudes during reentry wave propagation to those during normal wave propagation. The temporal changes in the reentry wave motion and magnetic field map patterns were also analyzed using two well-known MCG parameters: the current dipole direction and strength. The current vector in a reentry wave forms a rotating spiral. We delineated the magnetic field using the changes in the vector angle during a reentry wave, demonstrating that the MCG pattern can be helpful for theoretical analysis of reentry waves.

  9. Interfacial wave theory of pattern formation in solidification dendrites, fingers, cells and free boundaries

    CERN Document Server

    Xu, Jian-Jun

    2017-01-01

    This comprehensive work explores interfacial instability and pattern formation in dynamic systems away from the equilibrium state in solidification and crystal growth. Further, this significantly expanded 2nd edition introduces and reviews the progress made during the last two decades. In particular, it describes the most prominent pattern formation phenomena commonly observed in material processing and crystal growth in the framework of the previously established interfacial wave theory, including free dendritic growth from undercooled melt, cellular growth and eutectic growth in directional solidification, as well as viscous fingering in Hele-Shaw flow. It elucidates the key problems, systematically derives their mathematical solutions by pursuing a unified, asymptotic approach, and finally carefully examines these results by comparing them with the available experimental results. The asymptotic approach described here will be useful for the investigation of pattern formation phenomena occurring in a much b...

  10. Application of Refactoring and Design Pattern in Land Information System Development

    Institute of Scientific and Technical Information of China (English)

    CHEN Luyao; YUE Jianwei; JIANG Weiguo; LI Jing; CHEN Yunhao

    2007-01-01

    The unceasing change problem of land information systems can be resolved through the refactoring and design pattern. To promote the implementation of design pattern and refactoring methods in developing land information systems reusing software design, applying refactoring methods to the abstract factory and decorator design patterns in land information system development is discussed.

  11. Control of traveling-wave oscillations and bifurcation behavior in central pattern generators

    Science.gov (United States)

    Landsman, Alexandra S.; Slotine, Jean-Jacques

    2012-10-01

    Understanding synchronous and traveling-wave oscillations, particularly as they relate to transitions between different types of behavior, is a central problem in modeling biological systems. Here, we address this problem in the context of central pattern generators (CPGs). We use contraction theory to establish the global stability of a traveling-wave or synchronous oscillation, determined by the type of coupling. This opens the door to better design of coupling architectures to create the desired type of stable oscillations. We then use coupling that is both amplitude and phase dependent to create either globally stable synchronous or traveling-wave solutions. Using the CPG motor neuron network of a leech as an example, we show that while both traveling and synchronous oscillations can be achieved by several types of coupling, the transition between different types of behavior is dictated by a specific coupling architecture. In particular, it is only the “repulsive” but not the commonly used phase or rotational coupling that can explain the transition to high-frequency synchronous oscillations that have been observed in the heartbeat pattern generator of a leech. This shows that the overall dynamics of a CPG can be highly sensitive to the type of coupling used, even for coupling architectures that are widely believed to produce the same qualitative behavior.

  12. Complex wave excitations and chaotic patterns for a general (2+1)-dimensional Korteweg-de Vries system

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Hua; Fang Jian-Ping; Zheng Chun-Long

    2008-01-01

    Starting from an improved mapping approach and a linear variable separation approach, a new family of exact solutions (including solitary wave solutions, periodic wave solutions and rational function solutions) with arbitrary functions for a general (2+1)-dimensional Korteweg de Vries system (GKdV) is derived. According to the derived solutions, we obtain some novel dromion-lattice solitons, complex wave excitations and chaotic patterns for the GKdV system.

  13. Beam pattern improvement by compensating array nonuniformities in a guided wave phased array

    Science.gov (United States)

    Kwon, Hyu-Sang; Lee, Seung-Seok; Kim, Jin-Yeon

    2013-08-01

    This paper presents a simple data processing algorithm which can improve the performance of a uniform circular array based on guided wave transducers. The algorithm, being intended to be used with the delay-and-sum beamformer, effectively eliminates the effects of nonuniformities that can significantly degrade the beam pattern. Nonuniformities can arise intrinsically from the array geometry when the circular array is transformed to a linear array for beam steering and extrinsically from unequal conditions of transducers such as element-to-element variations of sensitivity and directivity. The effects of nonuniformities are compensated by appropriately imposing weight factors on the elements in the projected linear array. Different cases are simulated, where the improvements of the beam pattern, especially the level of the highest sidelobe, are clearly seen, and related issues are discussed. An experiment is performed which uses A0 mode Lamb waves in a steel plate, to demonstrate the usefulness of the proposed method. The discrepancy between theoretical and experimental beam patterns is explained by accounting for near-field effects.

  14. Wave Patterns in Cell Membrane and Actin Cortex Uncoupled from Chemotactic Signals.

    Science.gov (United States)

    Gerisch, Günther; Ecke, Mary

    2016-01-01

    When cells of Dictyostelium discoideum orientate in a gradient of chemoattractant, they are polarized into a protruding front pointing toward the source of attractant, and into a retracting tail. Under the control of chemotactic signal inputs, Ras is activated and PIP3 is synthesized at the front, while the PIP3-degrading phosphatase PTEN decorates the tail region. As a result of signal transduction, actin filaments assemble at the front into dendritic structures associated with the Arp2/3 complex, in contrast to the tail region where a loose actin meshwork is associated with myosin-II and cortexillin, an antiparallel actin-bundling protein. In axenically growing strains of D. discoideum, wave patterns built by the same components evolve in the absence of any external signal input. Since these autonomously generated patterns are constrained to the plane of the substrate-attached cell surface, they are optimally suited to the optical analysis of state transitions between front-like and tail-like states of the membrane and the actin cortex. Here, we describe imaging techniques using fluorescent proteins to probe for the state of the membrane, the reorganization of the actin network, and the dynamics of wave patterns.

  15. E × B shear pattern formation by radial propagation of heat flux waves

    OpenAIRE

    Kosuga, Y; Diamond, PH; Dif-Pradalier, G; Gürcan, OD

    2014-01-01

    A novel theory to describe the formation of E×B flow patterns by radially propagating heat flux waves is presented. A model for heat avalanche dynamics is extended to include a finite delay time between the instantaneous heat flux and the mean flux, based on an analogy between heat avalanche dynamics and traffic flow dynamics. The response time introduced here is an analogue of the drivers' response time in traffic dynamics. The microscopic foundation for the time delay is the time for mixing...

  16. Near-field imaging of interference pattern of counterpropagating evanescent waves

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Bozhevolnaya, Elena A.

    1999-01-01

    It is generally accepted that measurement of of the contrast of the intensity interference pattern formed by two counterpropagating evanescent waves can be used to characterize the resolving power of a collection near-field microscope. We argue that, if the light collected by a fiber probe...... propagates toward a detector in the form of guided fiber modes, then this perception is wrong. Using symmetry arguments and simple calculations, we show that, if an extended fiber probe is axially symmetric and oriented perpendicular to the propagation direction, then the measured contrast should always...

  17. On the influence of surface plasmon-polariton waves on pattern formation upon laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, E.L., E-mail: gurevich@lat.rub.de [Ruhr-Universität Bochum, Chair of Applied Laser Technology, Universitätsstraße 150, 44801 Bochum (Germany)

    2013-08-01

    Here we analyze whether the laser-induced periodic surface structures (LIPSS), which appear on solid surfaces exposed to single-pulse femtosecond laser radiation, can be explained by excitation of surface plasmon-polariton waves. We demonstrate that excitation of the surface plasmons is impossible in the laser-ablation experiments, since the excitation conditions are not fulfilled. Moreover, properties and morphology of the observed periodic patterns contradict to the theory of the plasmonic nature of the LIPSS. The results are illustrated with experimental examples.

  18. Links of the significant wave height distribution in the Mediterranean sea with the Northern Hemisphere teleconnection patterns

    Directory of Open Access Journals (Sweden)

    P. Lionello

    2008-06-01

    Full Text Available This study analyzes the link between the SWH (Significant Wave Height distribution in the Mediterranean Sea during the second half of the 20th century and the Northern Hemisphere SLP (Sea Level Pressure teleconnection patterns.

    The SWH distribution is computed using the WAM (WAve Model forced by the surface wind fields provided by the ERA-40 reanalysis for the period 1958–2001. The time series of mid-latitude teleconnection patterns are downloaded from the NOAA web site. This study shows that several mid-latitude patterns are linked to the SWH field in the Mediterranean, especially in its western part during the cold season: East Atlantic Pattern (EA, Scandinavian Pattern (SCA, North Atlantic Oscillation (NAO, East Atlantic/West Russia Pattern (EA/WR and East Pacific/ North Pacific Pattern (EP/NP. Though the East Atlantic pattern exerts the largest influence, it is not sufficient to characterize the dominant variability. NAO, though relevant, has an effect smaller than EA and comparable to other patterns. Some link results from possibly spurious structures. Patterns which have a very different global structure are associated to similar spatial features of the wave variability in the Mediterranean Sea. These two problems are, admittedly, shortcomings of this analysis, which shows the complexity of the response of the Mediterranean SWH to global scale SLP teleconnection patterns.

  19. Precise Manipulation and Patterning of Protein Crystals for Macromolecular Crystallography Using Surface Acoustic Waves.

    Science.gov (United States)

    Guo, Feng; Zhou, Weijie; Li, Peng; Mao, Zhangming; Yennawar, Neela H; French, Jarrod B; Huang, Tony Jun

    2015-06-01

    Advances in modern X-ray sources and detector technology have made it possible for crystallographers to collect usable data on crystals of only a few micrometers or less in size. Despite these developments, sample handling techniques have significantly lagged behind and often prevent the full realization of current beamline capabilities. In order to address this shortcoming, a surface acoustic wave-based method for manipulating and patterning crystals is developed. This method, which does not damage the fragile protein crystals, can precisely manipulate and pattern micrometer and submicrometer-sized crystals for data collection and screening. The technique is robust, inexpensive, and easy to implement. This method not only promises to significantly increase efficiency and throughput of both conventional and serial crystallography experiments, but will also make it possible to collect data on samples that were previously intractable.

  20. Circadian pattern of fibrillatory events in non-Brugada-type idiopathic ventricular fibrillation with a focus on J waves.

    Science.gov (United States)

    Aizawa, Yoshiyasu; Sato, Masahito; Ohno, Seiko; Horie, Minoru; Takatsuki, Seiji; Fukuda, Keiichi; Chinushi, Masaomi; Usui, Tatsuya; Aonuma, Kazutaka; Hosaka, Yukio; Haissaguerre, Michel; Aizawa, Yoshifusa

    2014-12-01

    The circadian pattern of ventricular fibrillation (VF) episodes in patients with idiopathic ventricular fibrillation (IVF) is poorly understood. The purpose of this study was to assess the circadian pattern of VF occurrence in patients with IVF. Excluding Brugada syndrome and other primary electrical diseases, the circadian pattern of VF occurrence was determined in 64 patients with IVF. The clinical and electrocardiographic characteristics were compared among patients with nocturnal (midnight to 6:00 AM) VF and nonnocturnal VF in relation to J waves. A J wave was defined as either notching or a slur at the QRS terminal >0.1 mV above the isoelectric line in contiguous leads. The overall distribution pattern of VF occurrence showed 2 peaks at approximately 6:00 AM and around 8:00 PM. Nocturnal VF was observed in 20 patients (31.3%), and J waves were present in 14 of these 20 individuals (70.0%), whereas J waves were less frequent in the 44 nonnocturnal patients with VF: 16 (36.4%) (P = .0117). Among patients with J waves, nocturnal VF was observed in 46.7% with a peak at approximately 4:00 AM. Nocturnal VF was less common in patients without J waves, occurring in only 17.6% (P = .0124). Both the type and location of J waves and the pattern of the ST segment were similar between the nocturnal and nonnocturnal VF groups. J waves were associated with a VF storm and long-term arrhythmia recurrence. In IVF, the presence of J waves may characterize a higher nocturnal incidence of VF and a higher acute and chronic risk of recurrence. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  1. Continuum modelling of piston driven shock waves through granular gases and ensuing pattern formations

    Science.gov (United States)

    Sirmas, Nick; Radulescu, Matei

    2015-11-01

    Two-dimensional event-driven Molecular Dynamics (MD) simulations were previously completed to investigate the stability of piston driven shock waves through dilute granular gases. By considering viscoelastic collisions, allowing for finite dissipation within the shock wave, instabilities were found in the form of distinctive high density non-uniformities and convective rolls within the shock structure. This work is now extended to the continuum level. Euler and Navier-Stokes equations for granular gases are modelled with a modified cooling rate to include an impact threshold necessary for inelastic collisions. The shock structure predicted by the continuum formulation is found in good agreement with the structure obtained by MD. Non-linear stability analyses of the travelling wave solution are performed, showing a neutrally stable structure and responding only to fluctuations in the upstream state. Introducing strong perturbations to the incoming density field, in accordance with the spacial fluctuations in upstream state seen in MD, yields similar instabilities as those previously observed. While the inviscid model predicts a highly turbulent structure from these perturbations, the inclusion of viscosity yields comparable wavelengths of pattern formations to those seen in MD.

  2. Wave-processing of long-scale information by neuronal chains.

    Directory of Open Access Journals (Sweden)

    José Antonio Villacorta-Atienza

    Full Text Available Investigation of mechanisms of information handling in neural assemblies involved in computational and cognitive tasks is a challenging problem. Synergetic cooperation of neurons in time domain, through synchronization of firing of multiple spatially distant neurons, has been widely spread as the main paradigm. Complementary, the brain may also employ information coding and processing in spatial dimension. Then, the result of computation depends also on the spatial distribution of long-scale information. The latter bi-dimensional alternative is notably less explored in the literature. Here, we propose and theoretically illustrate a concept of spatiotemporal representation and processing of long-scale information in laminar neural structures. We argue that relevant information may be hidden in self-sustained traveling waves of neuronal activity and then their nonlinear interaction yields efficient wave-processing of spatiotemporal information. Using as a testbed a chain of FitzHugh-Nagumo neurons, we show that the wave-processing can be achieved by incorporating into the single-neuron dynamics an additional voltage-gated membrane current. This local mechanism provides a chain of such neurons with new emergent network properties. In particular, nonlinear waves as a carrier of long-scale information exhibit a variety of functionally different regimes of interaction: from complete or asymmetric annihilation to transparent crossing. Thus neuronal chains can work as computational units performing different operations over spatiotemporal information. Exploiting complexity resonance these composite units can discard stimuli of too high or too low frequencies, while selectively compress those in the natural frequency range. We also show how neuronal chains can contextually interpret raw wave information. The same stimulus can be processed differently or identically according to the context set by a periodic wave train injected at the opposite end of the

  3. Qualitative pattern classification of shear wave elastography for breast masses: How it correlates to quantitative measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung Hyun, E-mail: lvjenny0417@gmail.com [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Department of Radiology, Research Institute of Radiological Science, Yonsei University, College of Medicine (Korea, Republic of); Ko, Kyung Hee, E-mail: yourheeya@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Jung, Hae Kyoung, E-mail: AA40501@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Lee, Jong Tae, E-mail: jtlee@cha.ac.kr [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of)

    2013-12-01

    Objective: To determine the correlation of qualitative shear wave elastography (SWE) pattern classification to quantitative SWE measurements and whether it is representative of quantitative SWE values with similar performances. Methods: From October 2012 to January 2013, 267 breast masses of 236 women (mean age: 45.12 ± 10.54 years, range: 21–88 years) who had undergone ultrasonography (US), SWE, and subsequent biopsy were included. US BI-RADS final assessment and qualitative and quantitative SWE measurements were recorded. Correlation between pattern classification and mean elasticity, maximum elasticity, elasticity ratio and standard deviation were evaluated. Diagnostic performances of grayscale US, SWE parameters, and US combined to SWE values were calculated and compared. Results: Of the 267 breast masses, 208 (77.9%) were benign and 59 (22.1%) were malignant. Pattern classifications significantly correlated with all quantitative SWE measurements, showing highest correlation with maximum elasticity, r = 0.721 (P < 0.001). Sensitivity was significantly decreased in US combined to SWE measurements to grayscale US: 69.5–89.8% to 100.0%, while specificity was significantly improved: 62.5–81.7% to 13.9% (P < 0.001). Area under the ROC curve (A{sub z}) did not show significant differences between grayscale US to US combined to SWE (P > 0.05). Conclusion: Pattern classification shows high correlation to maximum stiffness and may be representative of quantitative SWE values. When combined to grayscale US, SWE improves specificity of US.

  4. How to prepare for the next waves of Information Assurance issues?

    NARCIS (Netherlands)

    Luiijf, H.A.M.

    2006-01-01

    L'histore se répète. In general, each development wave of new technology shows a lack of security. The same lack of security can be found in the area of information and communications technology resulting in a lack of Critical Information Infrastructure (CII) Assurance. By looking back, we can predi

  5. The Concept of Data Model Pattern Based on Fully Communication Oriented Information Modeling (FCO-IM

    Directory of Open Access Journals (Sweden)

    Fazat Nur Azizah

    2010-04-01

    Full Text Available Just as in many areas of software engineering, patterns have been used in data modeling to create high quality data models. We provide a concept of data model pattern based on Fully Communication Oriented Information Modeling (FCO-IM, a fact oriented data modeling method. A data model pattern is defined as the relation between context, problem, and solution. This definition is adopted from the concept of pattern by Christopher Alexander. We define the concept of Information Grammar for Pattern (IGP in the solution part of a pattern, which works as a template to create a data model. The IGP also shows how a pattern can relate to other patterns. The data model pattern concept is then used to describe 15 data model patterns, organized into 4 categories. A case study on geographical location is provided to show the use of the concept in a real case.

  6. Measurement of Large Spiral and Target Waves in Chemical Reaction-Diffusion-Advection Systems: Turbulent Diffusion Enhances Pattern Formation

    Science.gov (United States)

    von Kameke, A.; Huhn, F.; Muñuzuri, A. P.; Pérez-Muñuzuri, V.

    2013-02-01

    In the absence of advection, reaction-diffusion systems are able to organize into spatiotemporal patterns, in particular spiral and target waves. Whenever advection is present that can be parametrized in terms of effective or turbulent diffusion D*, these patterns should be attainable on a much greater, boosted length scale. However, so far, experimental evidence of these boosted patterns in a turbulent flow was lacking. Here, we report the first experimental observation of boosted target and spiral patterns in an excitable chemical reaction in a quasi-two-dimensional turbulent flow. The wave patterns observed are ˜50 times larger than in the case of molecular diffusion only. We vary the turbulent diffusion coefficient D* of the flow and find that the fundamental Fisher-Kolmogorov-Petrovsky-Piskunov equation, vf∝D*, for the asymptotic speed of a reactive wave remains valid. However, not all measures of the boosted wave scale with D* as expected from molecular diffusion, since the wave fronts turn out to be highly filamentous.

  7. E × B shear pattern formation by radial propagation of heat flux waves

    Energy Technology Data Exchange (ETDEWEB)

    Kosuga, Y., E-mail: kosuga@riam.kyushu-u.ac.jp [WCI Center for Fusion Theory, NFRI, Daejeon (Korea, Republic of); IAS and RIAM, Kyushu University, Fukuoka (Japan); Diamond, P. H. [WCI Center for Fusion Theory, NFRI, Daejeon (Korea, Republic of); CASS and CMTFO, University of California, San Diego, California 92093 (United States); Dif-Pradalier, G. [CEA, IRFM, Paul-lez-Durance Cedex (France); Gürcan, Ö. D. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Palaiseau (France)

    2014-05-15

    A novel theory to describe the formation of E×B flow patterns by radially propagating heat flux waves is presented. A model for heat avalanche dynamics is extended to include a finite delay time between the instantaneous heat flux and the mean flux, based on an analogy between heat avalanche dynamics and traffic flow dynamics. The response time introduced here is an analogue of the drivers' response time in traffic dynamics. The microscopic foundation for the time delay is the time for mixing of the phase space density. The inclusion of the finite response time changes the model equation for avalanche dynamics from Burgers equation to a nonlinear telegraph equation. Based on the telegraph equation, the formation of heat flux jams is predicted. The growth rate and typical interval of jams are calculated. The connection of the jam interval to the typical step size of the E×B staircase is discussed.

  8. Simulation of Chromium Atom Deposition Pattern in a Gaussain Laser Standing Wave with Different Laser Power

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-Tao; ZHU Bao-Hua

    2009-01-01

    One-dimensional deposition of a neutral chromium atomic beam focused by a near-resonant Gaussian standing-laser field is discussed by using a fourth-order Runge-Kutta type algorithm. The deposition pattern of neutral chromium atoms in a laser standing wave with different laser power is discussed and the simulation result shows that the full width at half maximum (FWHM) of a nanometer stripe is 115nm and the contrast is 2.5:1 with laser power 3.93mW; the FWHM is 0.Snm and the contrast is 27:1 with laser power 16mW, the optimal laser power; but with laser power increasing to 50mW, the nanometer structure forms multi-crests and the quality worsens quickly with increasing laser power.

  9. Information and Motion Pattern Learning and Analysis Using Neural Techniques

    Science.gov (United States)

    2009-02-28

    development and application of neural models for higher-level information fusion at Levels 2+/3 according to the JDL Data Fusion Group Process Model. We...application of neural models for higher-level information fusion at Levels 2+/3 according to the JDL Data Fusion Group Process Model. We explored several...and application of neural models of information fusion at Levels 2+/3 according to the JDL Data Fusion Group Process Model (Figure 1) [1, 2]. We

  10. Jacobian-free Newton-Krylov methods with GPU acceleration for computing nonlinear ship wave patterns

    CERN Document Server

    Pethiyagoda, Ravindra; Moroney, Timothy J; Back, Julian M

    2014-01-01

    The nonlinear problem of steady free-surface flow past a submerged source is considered as a case study for three-dimensional ship wave problems. Of particular interest is the distinctive wedge-shaped wave pattern that forms on the surface of the fluid. By reformulating the governing equations with a standard boundary-integral method, we derive a system of nonlinear algebraic equations that enforce a singular integro-differential equation at each midpoint on a two-dimensional mesh. Our contribution is to solve the system of equations with a Jacobian-free Newton-Krylov method together with a banded preconditioner that is carefully constructed with entries taken from the Jacobian of the linearised problem. Further, we are able to utilise graphics processing unit acceleration to significantly increase the grid refinement and decrease the run-time of our solutions in comparison to schemes that are presently employed in the literature. Our approach provides opportunities to explore the nonlinear features of three-...

  11. For information: Geneva University - The search for gravitational waves. Physical motivations and experimental perspectives

    CERN Multimedia

    2005-01-01

    UNIVERSITE DE GENEVE ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet - 1211 GENEVE 4 Tél : (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 11 May PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium The search for gravitational waves. Physical motivations and experimental perspectives by Prof. Michele Maggiore / DPT-UniGe I will give an overview of gravitational-wave physics, addressing two main questions: What are the physical motivations for gravitational-wave research, both from the point of view of astrophysics and of high-energy physics. Present status and future perspectives of gravitational-wave experiments. Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer: A. Cervera Villanueva

  12. Organization of pattern information in the pattern based software development: A POMSDP model

    Institute of Scientific and Technical Information of China (English)

    TANG Yong; LIU Ri-guang; WANG Yan

    2008-01-01

    Focused on the lack of proper organization for patterns in the development of pattern based software, a POMSDP model with layered tree structure for organizing patterns during the process of development was put forward. The model and its interrelated concepts were strictly defined and introduced by applying the theory of set, symbolic logic and pattern, which ensures the correctness, maturity and expansibility of the model. The expansibility of the model was discussed mainly. The basic realization and the application in the automatic que-ry system were presented. Based on the existing software development methods, the POMSDP model resolves the problem of chaos in the application of patterns, strengthens the controllability of the system, and facilitates the improvement, maintenance, expansion, and especially the reengineering of the software system.

  13. Fulfilling Educational Aspirations: Latino Students' College Information Seeking Patterns

    Science.gov (United States)

    Martinez, Sylvia; Cervera, Yesenia Lucia

    2012-01-01

    A nationally representative sample of high school students is used to examine where students go for college information and how those information sources affect the number of schools to which students apply. Results show that Latino/a students are least likely to access college sources and have applied to the fewest number of schools. Among…

  14. Information-theoretic approach to the gravitational-wave burst detection problem

    Science.gov (United States)

    Lynch, Ryan; Vitale, Salvatore; Essick, Reed; Katsavounidis, Erik; Robinet, Florent

    2017-05-01

    The observational era of gravitational-wave astronomy began in the fall of 2015 with the detection of GW150914. One potential type of detectable gravitational wave is short-duration gravitational-wave bursts, whose waveforms can be difficult to predict. We present the framework for a detection algorithm for such burst events—oLIB—that can be used in low latency to identify gravitational-wave transients. This algorithm consists of (1) an excess-power event generator based on the Q transform—Omicron—, (2) coincidence of these events across a detector network, and (3) an analysis of the coincident events using a Markov chain Monte Carlo Bayesian evidence calculator—LALInferenceBurst. These steps compress the full data streams into a set of Bayes factors for each event. Through this process, we use elements from information theory to minimize the amount of information regarding the signal-versus-noise hypothesis that is lost. We optimally extract this information using a likelihood-ratio test to estimate a detection significance for each event. Using representative archival LIGO data across different burst waveform morphologies, we show that the algorithm can detect gravitational-wave burst events of astrophysical strength in realistic instrumental noise. We also demonstrate that the combination of Bayes factors by means of a likelihood-ratio test can improve the detection efficiency of a gravitational-wave burst search. Finally, we show that oLIB's performance is robust against the choice of gravitational-wave populations used to model the likelihood-ratio test likelihoods.

  15. Approximate Sparsity Pattern Recovery: Information-Theoretic Lower Bounds

    CERN Document Server

    Reeves, Galen

    2010-01-01

    Recovery of the sparsity pattern (or support) of a sparse vector from a small number of noisy linear projections (or samples) is a common problem that arises in signal processing and statistics. In this paper, the high-dimensional setting is considered. It is shown that if the sampling rate and per-sample signal-to-noise ratio (SNR) are finite constants independent of the length of the vector, then the optimal sparsity pattern estimate will have a constant fraction of errors. Lower bounds on the sampling rate needed to attain a desired fraction of errors are given in terms of the SNR and various key parameters of the unknown vector. The tightness of the bounds in a scaling sense, as a function of the SNR and the fraction of errors, is established by comparison with existing achievable bounds. Near optimality is shown for a wide variety of practically motivated signal models.

  16. Generation of three-dimensional patterns through wave interaction in a model of free surface swirling flow

    Energy Technology Data Exchange (ETDEWEB)

    Fabre, D; Mougel, J, E-mail: david.fabre@imft.fr [Institut de Mécanique des Fluides de Toulouse (IMFT), University of Toulouse (France)

    2014-12-01

    The free surface flow in a cylindrical tank over a rotating bottom is known to support spectacular three-dimensional patterns, including deformation of the inner free surface into the shape of rotating polygons and sloshing behavior of the upper free surface (e.g. Iga et al 2014 Fluid Dyn. Res. 46 031409). Through a stability analysis of a simplified model of this flow, we show that such patterns can be explained as a resonance mechanism involving different families of waves. The approach extends a previous work (Tophøj et al 2013 Phys. Rev. Lett. 110 194502) which explained the rotating polygons as an interaction between gravity waves and centrifugal waves, under the assumption that the base flow can be modeled as a potential vortex. We show that this previous model is justified for strong rotation rates (Dry-Potential case), and that for weaker rotations it can be improved by introducing an inner vortex core in solid-body rotation, which either extends to the center of the plate (Wet case) or surrounds a dry central region (Dry-Composite case). The study of this improved model predicts two new kinds of instabilities. The first occurs at low rotations (Wet case) and results from an interaction between gravity waves and the Kelvin–Kirchhoff wave (namely, oscillation of the boundary of the vortex core). This instability is proposed to be at the origin of the sloshing phenomenon. The second new instability occurs, for moderate rotations, (Dry-Composite case) as an interaction between gravity waves and a ‘Kelvin-Centrifugal’ wave characterized by deformation of the inner surface and the vortex core boundary in opposite directions. This instability exists for all azimuthal wave numbers starting from m = 1, this case corresponding to a ‘monogon’ pattern. (paper)

  17. Wave reflection in a reaction-diffusion system: breathing patterns and attenuation of the echo.

    Science.gov (United States)

    Tsyganov, M A; Ivanitsky, G R; Zemskov, E P

    2014-05-01

    Formation and interaction of the one-dimensional excitation waves in a reaction-diffusion system with the piecewise linear reaction functions of the Tonnelier-Gerstner type are studied. We show that there exists a parameter region where the established regime of wave propagation depends on initial conditions. Wave phenomena with a complex behavior are found: (i) the reflection of waves at a growing distance (the remote reflection) upon their collision with each other or with no-flux boundaries and (ii) the periodic transformation of waves with the jumping from one regime of wave propagation to another (the periodic trigger wave).

  18. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...

  19. Analysis of Near-Field Diffraction Pattern of a Metallic Probe Tip with the Boundary Diffraction Wave Method

    Institute of Scientific and Technical Information of China (English)

    TANG Lin; GU Chun; CHEN Bo; WANG Pei; MING Hai; XIE Jian-Ping

    2005-01-01

    @@ The boundary diffraction wave theory is introduced to analyse a near-field diffraction (NFD) pattern of a metallic probe tip of apertureless scanning near-field microscopy. This method is simple and can give a clear physical picture. The polarization effect of the incident light and the different shapes of the metallic probe tip are simulated. The results show that the NFD pattern of the metallic probe tip is directly related to those factors.

  20. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves)

    Science.gov (United States)

    Nam, Jeonghun; Kim, Jae Young; Lim, Chae Seung

    2017-01-01

    We present continuous, sheathless microparticle patterning using conductive liquid (CL)-based standing surface acoustic waves (SSAWs). Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  1. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves

    Directory of Open Access Journals (Sweden)

    Jeonghun Nam

    2017-01-01

    Full Text Available We present continuous, sheathless microparticle patterning using conductive liquid (CL-based standing surface acoustic waves (SSAWs. Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  2. E-Government and Geographical Information Based Collaboration Patterns

    DEFF Research Database (Denmark)

    Schrøder, Lise; Hvingel, Line Træholt; Hansen, Henning Sten

    2010-01-01

    in regard of e-Government readiness. In Denmark the development of e-Government is characterised by a very informal, bottom-up approach, with a focus on standardisation, the use of geographic information systems (GIS) and IT-architecture. The organisational aspects have not been an issue of much attention....... A national survey conducted by the University of Aalborg and Geoforum Denmark shows that the way the different players actually collaborate is a determining factor for a successful development in the field of e-Government....

  3. W-waveform Standing Surface Acoustic Waves with Two Equilibrium Positions under Linear Phase Modulation for Patterning Microparticles into Alternate Grid Patterns

    CERN Document Server

    Lee, Junseok

    2016-01-01

    This paper presents W-waveform Standing Surface Acoustic Waves (W-SSAW), and as its application, patterning of two groups of microparticles with different sizes alternately without fixing firstly patterned particles. W-SSAW is constructed by two standing surface acoustic waves of frequencies $f$ and $2f$. Combined with linear phase modulation to translate Gor'kov potential at a constant speed, W-SSAW can selectively trap particles. The trapped particles follow the moving Gor'kov potential maintaining force equilibrium between Stokes' drag and the radiation force by W-SSAW. There exist two asymmetric equilibrium positions every period, and by the asymmetry, each group of particles is trapped at different equilibrium positions to form an alternate pattern. This technique is extended to two-dimensional alternate patterning by maintaining phase difference $90^\\circ$ between X- and Y-directional W-SSAWs. The patterning method utilizing W-SSAW is advantageous over SSAW-based patterning in that it does not require t...

  4. Network structure and patterns of information diversity on Twitter

    CERN Document Server

    Shore, Jesse; Dellarocas, Chrysanthos

    2016-01-01

    Social media have great potential to support diverse information sharing, but there is widespread concern that platforms like Twitter do not result in communication between those who hold contradictory viewpoints. Because users can choose whom to follow, prior research suggests that social media users exist in 'echo chambers' or become polarized. We seek evidence of this in a complete cross section of hyperlinks posted on Twitter, using previously validated measures of the political slant of news sources to study information diversity. Contrary to prediction, we find that the average account posts links to more politically moderate news sources than the ones they receive in their own feed. However, members of a tiny network core do exhibit cross-sectional evidence of polarization and are responsible for the majority of tweets received overall due to their popularity and activity, which could explain the widespread perception of polarization on social media.

  5. Contraction of Information on Brain Wave Fluctuations by Information Geometrical Approach

    Science.gov (United States)

    Konno, Hidetoshi

    2005-08-01

    We will first propose a method of EEG signal identification with the use of the stochastic complex Ginzburg-Landau (CGL) equation having complex coefficients with the aid of the method of information geometrical approach to determine the system parameters. After the contracting information on the natures of fluctuations of amplitude and phase in the EEG signals on human scalp, we combine the information with other information such as complex measures like Higuchi's fractal dimension and multi-scale entropies. A new theory of unification of the information is also proposed. To exhibit the potentiality of our new method, we show the result of application of the theory and method to practical EEG data from elderly sound and demented people.

  6. SAR Imaging of Wave Tails: Recognition of Second Mode Internal Wave Patterns and Some Mechanisms of their Formation

    Science.gov (United States)

    da Silva, Jose C. B.; Magalhaes, J. M.; Buijsman, M. C.; Garcia, C. A. E.

    2016-08-01

    Mode-2 internal waves are usually not as energetic as larger mode-1 Internal Solitary Waves (ISWs), but they have attracted a great deal of attention in recent years because they have been identified as playing a significant role in mixing shelf waters [1]. This mixing is particularly effective for mode-2 ISWs because the location of these waves in the middle of the pycnocline plays an important role in eroding the barrier between the base of the surface mixed layer and the stratified deep layer below. An urgent problem in physical oceanography is therefore to account for the magnitude and distribution of ISW-driven mixing, including mode-2 ISWs. Several generation mechanisms of mode-2 ISWs have been identified. These include: (1) mode-1 ISWs propagating onshore (shoaling) and entering the breaking instability stage, or propagating over a steep sill; (2) a mode-1 ISW propagating offshore (antishoaling) over steep slopes of the shelf break, and undergoing modal transformation; (3) intrusion of the whole head of a gravity current into a three-layer fluid; (4) impingement of an internal tidal beam on the pycnocline, itself emanating from critical bathymetry; (5) nonlinear disintegration of internal tide modes; (6) lee wave mechanism. In this paper we provide methods to identify internal wave features denominated "Wave Tails" in SAR images of the ocean surface, which are many times associated with second mode internal waves. The SAR case studies that are presented portray evidence of the aforementioned generation mechanisms, and we further discuss possible methods to discriminate between the various types of mode-2 ISWs in SAR images, that emerge from these physical mechanisms. Some of the SAR images correspond to numerical simulations with the MITgcm in fully nonlinear and nonhydrostatic mode and in a 2D configuration with realistic stratification, bathymetry and other environmental conditions.Results of a global survey with some of these observations are presented

  7. Recombination patterns reveal information about centromere location on linkage maps

    DEFF Research Database (Denmark)

    Limborg, Morten T.; McKinney, Garrett J.; Seeb, Lisa W.

    2016-01-01

    , approximate centromere placement is possible by phasing the same data used to generate linkage maps. Assuming one obligate crossover per chromosome arm, information about centromere location can be revealed by tracking the accumulated recombination frequency along linkage groups, similar to half....... mykiss) characterized by low and unevenly distributed recombination – a general feature of male meiosis in many species. Further, a high frequency of double crossovers along chromosome arms in barley reduced resolution for locating centromeric regions on most linkage groups. Despite these limitations......, our method should work well for high‐density maps in species with strong recombination interference and will enrich many existing and future mapping resources....

  8. Information Storage and Retrieval for Probe Storage using Optical Diffraction Patterns

    CERN Document Server

    van Honschoten, Joost; Koelmans, Wabe W; Parnell, Thomas P; Zaboronski, Oleg V

    2011-01-01

    A novel method for fast information retrieval from a probe storage device is considered. It is shown that information can be stored and retrieved using the optical diffraction patterns obtained by the illumination of a large array of cantilevers by a monochromatic light source. In thermo-mechanical probe storage, the information is stored as a sequence of indentations on the polymer medium. To retrieve the information, the array of probes is actuated by applying a bending force to the cantilevers. Probes positioned over indentations experience deflection by the depth of the indentation, probes over the flat media remain un-deflected. Thus the array of actuated probes can be viewed as an irregular optical grating, which creates a data-dependent diffraction pattern when illuminated by laser light. We develop a low complexity modulation scheme, which allows the extraction of information stored in the pattern of indentations on the media from Fourier coefficients of the intensity of the diffraction pattern. We th...

  9. Research on Novel Pattern of Agricultural Economy based on Accurate Information Management System: A Survey

    Institute of Scientific and Technical Information of China (English)

    Liang Wang; Mengyan Liu

    2015-01-01

    The agricultural development in the less developed districts is a big challenge as they are resource poor regions and crops are grown under more risky agro-ecological conditions. In this paper, we conduct research on novel pattern of agricultural economy based on accurate information management system. Agricultural information is the agriculture prenatal, during and aider the information process, mainly to solve the problems in the development of agricultural production. Rural information includes rural economic information, rural management and related information, rural information culture and the rural social service information. Our system modifies the efficiency of managing materials which will largely enhance the economical result for the agricultural activities.

  10. Managing Information Uncertainty in Wave Height Modeling for the Offshore Structural Analysis through Random Set

    Directory of Open Access Journals (Sweden)

    Keqin Yan

    2017-01-01

    Full Text Available This chapter presents a reliability study for an offshore jacket structure with emphasis on the features of nonconventional modeling. Firstly, a random set model is formulated for modeling the random waves in an ocean site. Then, a jacket structure is investigated in a pushover analysis to identify the critical wave direction and key structural elements. This is based on the ultimate base shear strength. The selected probabilistic models are adopted for the important structural members and the wave direction is specified in the weakest direction of the structure for a conservative safety analysis. The wave height model is processed in a P-box format when it is used in the numerical analysis. The models are applied to find the bounds of the failure probabilities for the jacket structure. The propagation of this wave model to the uncertainty in results is investigated in both an interval analysis and Monte Carlo simulation. The results are compared in context of information content and numerical accuracy. Further, the failure probability bounds are compared with the conventional probabilistic approach.

  11. An information-theoretic approach to the gravitational-wave burst detection problem

    Science.gov (United States)

    Katsavounidis, E.; Lynch, R.; Vitale, S.; Essick, R.; Robinet, F.

    2016-03-01

    The advanced era of gravitational-wave astronomy, with data collected in part by the LIGO gravitational-wave interferometers, has begun as of fall 2015. One potential type of detectable gravitational waves is short-duration gravitational-wave bursts, whose waveforms can be difficult to predict. We present the framework for a new detection algorithm - called oLIB - that can be used in relatively low-latency to turn calibrated strain data into a detection significance statement. This pipeline consists of 1) a sine-Gaussian matched-filter trigger generator based on the Q-transform - known as Omicron -, 2) incoherent down-selection of these triggers to the most signal-like set, and 3) a fully coherent analysis of this signal-like set using the Markov chain Monte Carlo (MCMC) Bayesian evidence calculator LALInferenceBurst (LIB). We optimally extract this information by using a likelihood-ratio test (LRT) to map these search statistics into a significance statement. Using representative archival LIGO data, we show that the algorithm can detect gravitational-wave burst events of realistic strength in realistic instrumental noise with good detection efficiencies across different burst waveform morphologies. With support from the National Science Foundation under Grant PHY-0757058.

  12. Capturing atmospheric effects on 3D millimeter wave radar propagation patterns

    Science.gov (United States)

    Cook, Richard D.; Fiorino, Steven T.; Keefer, Kevin J.; Stringer, Jeremy

    2016-05-01

    Traditional radar propagation modeling is done using a path transmittance with little to no input for weather and atmospheric conditions. As radar advances into the millimeter wave (MMW) regime, atmospheric effects such as attenuation and refraction become more pronounced than at traditional radar wavelengths. The DoD High Energy Laser Joint Technology Offices High Energy Laser End-to-End Operational Simulation (HELEEOS) in combination with the Laser Environmental Effects Definition and Reference (LEEDR) code have shown great promise simulating atmospheric effects on laser propagation. Indeed, the LEEDR radiative transfer code has been validated in the UV through RF. Our research attempts to apply these models to characterize the far field radar pattern in three dimensions as a signal propagates from an antenna towards a point in space. Furthermore, we do so using realistic three dimensional atmospheric profiles. The results from these simulations are compared to those from traditional radar propagation software packages. In summary, a fast running method has been investigated which can be incorporated into computational models to enhance understanding and prediction of MMW propagation through various atmospheric and weather conditions.

  13. Long-lived force patterns and deformation waves at repulsive epithelial boundaries

    Science.gov (United States)

    Rodríguez-Franco, Pilar; Brugués, Agustí; Marín-Llauradó, Ariadna; Conte, Vito; Solanas, Guiomar; Batlle, Eduard; Fredberg, Jeffrey J.; Roca-Cusachs, Pere; Sunyer, Raimon; Trepat, Xavier

    2017-10-01

    For an organism to develop and maintain homeostasis, cell types with distinct functions must often be separated by physical boundaries. The formation and maintenance of such boundaries are commonly attributed to mechanisms restricted to the cells lining the boundary. Here we show that, besides these local subcellular mechanisms, the formation and maintenance of tissue boundaries involves long-lived, long-ranged mechanical events. Following contact between two epithelial monolayers expressing, respectively, EphB2 and its ligand ephrinB1, both monolayers exhibit oscillatory patterns of traction forces and intercellular stresses that tend to pull cell-matrix adhesions away from the boundary. With time, monolayers jam, accompanied by the emergence of deformation waves that propagate away from the boundary. This phenomenon is not specific to EphB2/ephrinB1 repulsion but is also present during the formation of boundaries with an inert interface and during fusion of homotypic epithelial layers. Our findings thus unveil a global physical mechanism that sustains tissue separation independently of the biochemical and mechanical features of the local tissue boundary.

  14. Three-dimensional volume containing multiple two-dimensional information patterns

    Science.gov (United States)

    Nakayama, Hirotaka; Shiraki, Atsushi; Hirayama, Ryuji; Masuda, Nobuyuki; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

    2013-06-01

    We have developed an algorithm for recording multiple gradated two-dimensional projection patterns in a single three-dimensional object. When a single pattern is observed, information from the other patterns can be treated as background noise. The proposed algorithm has two important features: the number of patterns that can be recorded is theoretically infinite and no meaningful information can be seen outside of the projection directions. We confirmed the effectiveness of the proposed algorithm by performing numerical simulations of two laser crystals: an octagonal prism that contained four patterns in four projection directions and a dodecahedron that contained six patterns in six directions. We also fabricated and demonstrated an actual prototype laser crystal from a glass cube engraved by a laser beam. This algorithm has applications in various fields, including media art, digital signage, and encryption technology.

  15. Scale effects on information theory-based measures applied to streamflow patterns in two rural watersheds

    Science.gov (United States)

    Understanding streamflow patterns in space and time is important to improve the flood and drought forecasting, water resources management, and predictions of ecological changes. The objectives of this work were (a) to characterize the spatial and temporal patterns of streamflow using information the...

  16. Concurrent computation of connected pattern spectra for very large image information mining

    NARCIS (Netherlands)

    Wilkinson, Michael; Moschini, Ugo; Ouzounis, G.K.; Pesaresi, M.

    2012-01-01

    This paper presents a shared-memory parallel algorithm for computing connected pattern spectra from the Max-Tree structure. The pattern spectrum is an aggregated feature space derived directly from the tree-based image representation and is a powerful tool for interactive image information mining.

  17. Comparing spatial patterns of informal settlements between Nairobi and Dar es Salaam

    OpenAIRE

    Sirueri, Felix

    2015-01-01

    Currently, in many cities in the developing world, spatial data on informal settlements are generalized, outdated, or even non-existent. Moreover, there is a lack of comprehensive information about spatial factors that influence the location of informal settlements a cross different cities. These settlements continue to develop posing many urban challenges. This research employs locational and morphological parameters to measure and quantify the patterns of informal settlements using two exam...

  18. Splitting of quantum information in travelling wave fields using only linear optical elements

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, W B; De Almeida, N G; Avelar, A T; Baseia, B [Instituto de Fisica, Universidade Federal de Goias, 74.001-970, Goiania-GO (Brazil)

    2011-02-28

    In this paper we present a feasible post-selection scheme to split quantum information in the realm of travelling waves with success probability of 50%. Taking advantage of this scheme we have also proposed the generation of a class of W states useful for perfect teleportation and superdense coding. The scheme employs only linear optical elements as beam splitters (BS) and phase shifters, plus two photon counters and a source of two spontaneous parametric down-conversion photons. It is shown that splitting of quantum information with high fidelity is possible, even when using inefficient detectors and photoabsorption BS.

  19. Local Left Ventricular Epicardial J Waves and Late Potentials in Brugada Syndrome Patients with Inferolateral Early Repolarization Pattern

    Science.gov (United States)

    Nagase, Satoshi; Tanaka, Masamichi; Morita, Hiroshi; Nakagawa, Koji; Wada, Tadashi; Murakami, Masato; Nishii, Nobuhiro; Nakamura, Kazufumi; Ito, Hiroshi; Ohe, Tohru; Kusano, Kengo F.

    2017-01-01

    Background: Brugada syndrome (BrS) is characterized by J-point or ST-segment elevation on electrocardiograms (ECGs) and increased risk of ventricular fibrillation (VF). In BrS, epicardial depolarization abnormality with delayed potential on the right ventricular outflow tract is reportedly the predominant mechanism underlying VF. Yet VF occurrence is also associated with early repolarization (ER) pattern in the inferolateral ECG leads, which may represent the inferior and/or left lateral ventricular myocardium. The aim of this study was to examine epicardial electrograms recorded directly at the left ventricle (LV) in BrS patients after VF episodes. Methods: In 12 BrS patients who had experienced VF episodes and 17 control subjects, a multipolar catheter was introduced into the left lateral coronary vein for unipolar and bipolar electrogram recordings at the LV epicardium. Both inferior and lateral ER patterns on ECG were observed in three BrS patients and six control subjects. Results: In the epicardium, prominent J waves were detected using unipolar recording, and potentials after the QRS complex were detected using bipolar recording in three of the 12 BrS patients. These three patients also showed both inferior and lateral ER patterns on ECG. Neither prominent J waves nor potentials after the QRS complex were recorded at the endocardium of the LV in any of these three patients; nor were they seen at the epicardium in any of the control subjects. These features were accentuated on pilsicainide administration (n = 2) but diminished on constant atrial pacing (n = 3) and isoproterenol administration (n = 1). The J waves observed through unipolar recording coincided with the potentials after QRS complex observed through bipolar recording and with the inferolateral ER patterns on ECG. Conclusions: We recorded prominent J waves in unipolar electrogram and potentials after QRS complex in bipolar electrogram at the LV epicardium in BrS patients with global ER pattern

  20. Local Left Ventricular Epicardial J Waves and Late Potentials in Brugada Syndrome Patients with Inferolateral Early Repolarization Pattern.

    Science.gov (United States)

    Nagase, Satoshi; Tanaka, Masamichi; Morita, Hiroshi; Nakagawa, Koji; Wada, Tadashi; Murakami, Masato; Nishii, Nobuhiro; Nakamura, Kazufumi; Ito, Hiroshi; Ohe, Tohru; Kusano, Kengo F

    2017-01-01

    Background: Brugada syndrome (BrS) is characterized by J-point or ST-segment elevation on electrocardiograms (ECGs) and increased risk of ventricular fibrillation (VF). In BrS, epicardial depolarization abnormality with delayed potential on the right ventricular outflow tract is reportedly the predominant mechanism underlying VF. Yet VF occurrence is also associated with early repolarization (ER) pattern in the inferolateral ECG leads, which may represent the inferior and/or left lateral ventricular myocardium. The aim of this study was to examine epicardial electrograms recorded directly at the left ventricle (LV) in BrS patients after VF episodes. Methods: In 12 BrS patients who had experienced VF episodes and 17 control subjects, a multipolar catheter was introduced into the left lateral coronary vein for unipolar and bipolar electrogram recordings at the LV epicardium. Both inferior and lateral ER patterns on ECG were observed in three BrS patients and six control subjects. Results: In the epicardium, prominent J waves were detected using unipolar recording, and potentials after the QRS complex were detected using bipolar recording in three of the 12 BrS patients. These three patients also showed both inferior and lateral ER patterns on ECG. Neither prominent J waves nor potentials after the QRS complex were recorded at the endocardium of the LV in any of these three patients; nor were they seen at the epicardium in any of the control subjects. These features were accentuated on pilsicainide administration (n = 2) but diminished on constant atrial pacing (n = 3) and isoproterenol administration (n = 1). The J waves observed through unipolar recording coincided with the potentials after QRS complex observed through bipolar recording and with the inferolateral ER patterns on ECG. Conclusions: We recorded prominent J waves in unipolar electrogram and potentials after QRS complex in bipolar electrogram at the LV epicardium in BrS patients with global ER pattern

  1. Network Analysis of Atmospheric Rossby Wave Patterns in the Northern Midlatitudes

    Science.gov (United States)

    Martin, P.; Stolbova, V.; Kurths, J.

    2015-12-01

    Rossby waves, the primary contributors to weather and storms in the midlatitudes, are a major phenomenon in the upper atmosphere, and play a large role in poleward heat transport. Understanding the mechanism and features of Rossby waves are crucial for millions of people, especially due to the extreme events caused by Rossby Waves such as the Russian Heat Wave and the flood in Pakistan, both occurring in 2010. In this study, we use an idealized, regional, quasi-geostrophic, coupled ocean-atmosphere model (The Quasi-Geostrophic Coupled Model, or QGCM) to create Rossby waves in the northern hemisphere. We analyze these waves using the emerging technique of climate networks - a useful statistical tool for a range of complex systems, which has proven to be extremely useful in giving new insight into the climate system's behavior. Here, we create networks using different climatic variables, and investigate the properties of Rossby waves, including propagation speed and energy transport. We look at network measures, such as degree and link length, to determine the major features of Rossby waves. Finally, we compare our results to observed data, and show how our findings provide a better understanding of the different regimes of Rossby Waves, their features, and mechanisms of their propagation, which is crucial for forecasting on short and long-range time scales.

  2. Patterns of information-seeking for cancer on the internet: an analysis of real world data.

    Directory of Open Access Journals (Sweden)

    Yishai Ofran

    Full Text Available Although traditionally the primary information sources for cancer patients have been the treating medical team, patients and their relatives increasingly turn to the Internet, though this source may be misleading and confusing. We assess Internet searching patterns to understand the information needs of cancer patients and their acquaintances, as well as to discern their underlying psychological states. We screened 232,681 anonymous users who initiated cancer-specific queries on the Yahoo Web search engine over three months, and selected for study users with high levels of interest in this topic. Searches were partitioned by expected survival for the disease being searched. We compared the search patterns of anonymous users and their contacts. Users seeking information on aggressive malignancies exhibited shorter search periods, focusing on disease- and treatment-related information. Users seeking knowledge regarding more indolent tumors searched for longer periods, alternated between different subjects, and demonstrated a high interest in topics such as support groups. Acquaintances searched for longer periods than the proband user when seeking information on aggressive (compared to indolent cancers. Information needs can be modeled as transitioning between five discrete states, each with a unique signature representing the type of information of interest to the user. Thus, early phases of information-seeking for cancer follow a specific dynamic pattern. Areas of interest are disease dependent and vary between probands and their contacts. These patterns can be used by physicians and medical Web site authors to tailor information to the needs of patients and family members.

  3. An information-theoretic approach to the gravitational-wave burst detection problem

    CERN Document Server

    Lynch, Ryan; Essick, Reed; Katsavounidis, Erik; Robinet, Florent

    2015-01-01

    The advanced era of gravitational-wave astronomy, with data collected in part by the LIGO gravitational-wave interferometers, has begun as of fall 2015. One potential type of detectable gravitational waves is short-duration gravitational-wave bursts, whose waveforms can be difficult to predict. We present the framework for a new detection algorithm -- called \\textit{oLIB} -- that can be used in relatively low-latency to turn calibrated strain data into a detection significance statement. This pipeline consists of 1) a sine-Gaussian matched-filter trigger generator based on the Q-transform -- known as \\textit{Omicron} --, 2) incoherent down-selection of these triggers to the most signal-like set, and 3) a fully coherent analysis of this signal-like set using the Markov chain Monte Carlo (MCMC) Bayesian evidence calculator \\textit{LALInferenceBurst} (LIB). These steps effectively compress the full data stream into a set of search statistics for the most signal-like events, and we use elements from information t...

  4. Predicting the distribution of spiral waves from cell properties in a developmental-path model of Dictyostelium pattern formation.

    Directory of Open Access Journals (Sweden)

    Daniel Geberth

    2009-07-01

    Full Text Available The slime mold Dictyostelium discoideum is one of the model systems of biological pattern formation. One of the most successful answers to the challenge of establishing a spiral wave pattern in a colony of homogeneously distributed D. discoideum cells has been the suggestion of a developmental path the cells follow (Lauzeral and coworkers. This is a well-defined change in properties each cell undergoes on a longer time scale than the typical dynamics of the cell. Here we show that this concept leads to an inhomogeneous and systematic spatial distribution of spiral waves, which can be predicted from the distribution of cells on the developmental path. We propose specific experiments for checking whether such systematics are also found in data and thus, indirectly, provide evidence of a developmental path.

  5. Rotating waves during human sleep spindles organize global patterns of activity that repeat precisely through the night

    Science.gov (United States)

    Muller, Lyle; Piantoni, Giovanni; Koller, Dominik; Cash, Sydney S; Halgren, Eric; Sejnowski, Terrence J

    2016-01-01

    During sleep, the thalamus generates a characteristic pattern of transient, 11-15 Hz sleep spindle oscillations, which synchronize the cortex through large-scale thalamocortical loops. Spindles have been increasingly demonstrated to be critical for sleep-dependent consolidation of memory, but the specific neural mechanism for this process remains unclear. We show here that cortical spindles are spatiotemporally organized into circular wave-like patterns, organizing neuronal activity over tens of milliseconds, within the timescale for storing memories in large-scale networks across the cortex via spike-time dependent plasticity. These circular patterns repeat over hours of sleep with millisecond temporal precision, allowing reinforcement of the activity patterns through hundreds of reverberations. These results provide a novel mechanistic account for how global sleep oscillations and synaptic plasticity could strengthen networks distributed across the cortex to store coherent and integrated memories. DOI: http://dx.doi.org/10.7554/eLife.17267.001 PMID:27855061

  6. Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns.

    Science.gov (United States)

    Williams, Gareth J; Smith, Jennifer E; Conklin, Eric J; Gove, Jamison M; Sala, Enric; Sandin, Stuart A

    2013-01-01

    Kingman Reef and Palmyra Atoll in the central Pacific are among the most remote coral reefs on the planet. Here we describe spatial patterns in their benthic communities across reef habitats and depths, and consider these in the context of oceanographic gradients. Benthic communities at both locations were dominated by calcifying organisms (54-86% cover), namely hard corals (20-74%) and crustose coralline algae (CCA) (10-36%). While turf algae were relatively common at both locations (8-22%), larger fleshy macroalgae were virtually absent at Kingman (wave energy, with hard coral cover decreasing and becoming more spatially clustered with increased wave energy, likely as a result of physical damage leading to patches of coral in localized shelter. In contrast, the cover of turf algae at Kingman was positively related to wave energy, reflecting their ability to rapidly colonize newly available space. No significant patterns with wave energy were observed on Palmyra's forereef, suggesting that a more detailed model is required to study biophysical coupling there. Kingman, Palmyra, and other remote oceanic reefs provide interesting case studies to explore biophysical influences on benthic ecology and dynamics.

  7. The role of terahertz surface plasmons in the scattering pattern of electromagnetic waves in an unstable elliptical plasma antenna

    Science.gov (United States)

    Safari, S.; Jazi, B.

    2017-07-01

    The scattering phenomenon of plane waves from an unstable elliptical plasma antenna is investigated. The role of surface plasmon excitation in the scattering pattern is studied. In the antenna mentioned above, there is a metallic rod with dielectric cover embedded in a long plasma column with an elliptical cross section. The antenna is considered unstable because of the injection of an electron beam into the plasma layer. The effects of applied accelerating voltage and applied current intensity on the scattering pattern and resonance frequency are investigated. The geometrical structure and its effect on the scattering cross section and creation of new resonance frequency are studied.

  8. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Directory of Open Access Journals (Sweden)

    Shilei Liu

    2017-07-01

    Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

  9. The Shadow Knows: Inferring the Density Distribution of a Nonuniform Medium from Its Standing Wave Pattern

    Science.gov (United States)

    Binder, Philippe; Cunnyngham, Ian

    2012-01-01

    In a recent note in this journal, Gluck presents a beautiful demonstration of the standing wave generated by a strip of material with linearly varying width (a trapezoid). As expected, the resulting wave envelope (and its shadow) showed a varying wavelength--smaller as the strip width gets larger.

  10. Priming Infants to Attend to Color and Pattern Information in an Individuation Task

    Science.gov (United States)

    Wilcox, Teresa; Chapa, Catherine

    2004-01-01

    Wilcox (Cognition 72 (1999) 125) reported that infants are more sensitive to form than surface features when individuating objects in occlusion events: it is not until 7.5 months that infants spontaneously use pattern information, and 11.5 months that they spontaneously use color information, as the basis for object individuation. The present…

  11. Perspectives on the Federal Government and Health Information: Patterns, Impact, Expectations.

    Science.gov (United States)

    Lunin, Lois F.; And Others

    1987-01-01

    Nine articles examine patterns of federal health information services including: the current Administration's policy; the history of the National Library of Medicine; Federal Health Information Clearinghouses and other unique projects; the Center for the Utilization of Technology; marketing trends at the Government Printing Office; and…

  12. Wave

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    2008-01-01

    Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many t...

  13. An Improved Ocean Observing System for Coastal Louisiana: WAVCIS (WAVE-CURRENT-SURGE Information System )

    Science.gov (United States)

    Zhang, X.; Stone, G. W.; Gibson, W. J.; Braud, D.

    2005-05-01

    WAVCIS is a regional ocean observing and forecasting system. It was designed to measure, process, forecast, and distribute oceanographic and meteorological information. WAVCIS was developed and is maintained by the Coastal Studies Institute at Louisiana State University. The in-situ observing stations are distributed along the central Louisiana and Mississippi coast. The forecast region covers the entire Gulf of Mexico with emphasis on offshore Louisiana. By using state-of-the-art instrumentation, WAVCIS measures directional waves, currents, temperature, water level, conductivity, turbidity, salinity, dissolved oxygen, chlorophyll, Meteorological parameters include wind speed and direction, air pressure and temperature visibility and humidity. Through satellite communication links, the measured data are transmitted to the WAVCIS laboratory. After processing, they are available to the public via the internet on a near real-time basis. WAVCIS also includes a forecasting capability. Waves, tides, currents, and winds are forecast daily for up to 80 hours in advance. There are a number of numerical wave and surge models that can be used for forecasts. WAM and SWAN are used for operational purposes to forecast sea state. Tides at each station are predicted based on the harmonic constants calculated from past in-situ observations at respective sites. Interpolated winds from the ETA model are used as input forcing for waves. Both in-situ and forecast information are available online to the users through WWW. Interactive GIS web mapping is implemented on the WAVCIS webpage to visualize the model output and in-situ observational data. WAVCIS data can be queried, retrieved, downloaded, and analyzed through the web page. Near real-time numerical model skill assessment can also be performed by using the data from in-situ observing stations.

  14. The architecture of information architecture, interaction design and the patterning of digital information

    CERN Document Server

    Dade-Robertson, Martyn

    2011-01-01

    This book looks at relationships between the organization of physical objects in space and the organization of ideas. Historical, philosophical, psychological and architectural knowledge are united to develop an understanding of the relationship between information and its representation.Despite its potential to break the mould, digital information has relied on metaphors from a pre-digital era. In particular, architectural ideas have pervaded discussions of digital information, from the urbanization of cyberspace in science fiction, through to the adoption of spatial visualiz

  15. Information retrieval patterns and needs among practicing general surgeons: a statewide experience.

    OpenAIRE

    Shelstad, K R; Clevenger, F W

    1996-01-01

    Information retrieval has progressed from a reliance on traditional print sources to the modern era of computer databases and online networks. Surgeons, many from remote areas not served by professional medical libraries, must develop and maintain skills in information retrieval and management in both electronic and standard formats. One hundred thirty-three New Mexico general surgeons were surveyed to identify their information-seeking patterns in five areas: retrieval purposes, retrieval so...

  16. Pattern Selection, Wave Formation, Turbulence and Vortex Breakdown in Spiral Flows

    Science.gov (United States)

    1990-01-01

    problems in rotating plane Couette - Poiseuille flow " (joint work with George H. Knightly), Contemporary Math., 108 (1990), to appear. The following...continuum of periodic waves in rotating plane Couette flow , and an analytic description of a mechanism to generate the turbulent-like flows observed in...during the period of the report: (1) "Waves in rotating plane Couette flow " (joint work with George H. Knightly, University of Massachusetts), Geometry

  17. Exploring the complex pattern of information spreading in online blog communities

    CERN Document Server

    Pei, Sen; Tang, Shaoting; Zheng, Zhiming; Makse, Hernan A

    2015-01-01

    Information spreading in online social communities has attracted tremendous attention due to its utmost practical values in applications. Despite that several individual-level diffusion data have been investigated, we still lack the detailed understanding of the spreading pattern of information. Here, by comparing information flows and social links in a blog community, we find that the diffusion processes are induced by three different spreading mechanisms: social spreading, self-promotion and broadcast. Although numerous previous studies have employed epidemic spreading models to simulate information diffusion, we observe that such models fail to reproduce the realistic diffusion pattern. In respect to users behaviors, strikingly, we find that most users would stick to one specific diffusion mechanism. Moreover, our observations indicate that the social spreading is not only crucial for the structure of diffusion trees, but also capable of inducing more subsequent individuals to acquire the information. Our ...

  18. Pattern-based information portal for business plan co-creation

    DEFF Research Database (Denmark)

    Tanev, Stoyan; Bontchev, Boyan; Ruskov, Petko

    2010-01-01

    provide a basis for adopting similar solutions in the future within given business context. The article presents the system design of an information portal for business plan cocreation based on patterns. The portal is going to provide start-up and entrepreneurs with ready-to-modify business plan patterns...... in order to help them in development of effective and efficient business plans. It will facilitate entrepreneurs in co-experimenting and co-learning more frequently and faster. Moreover, the paper focuses on the software architecture of the pattern based portal and explains the functionality of its modules...

  19. Interference pattern of the sound field in the presence of an internal Kelvin wave in a stratified lake.

    Science.gov (United States)

    Katsnelson, Boris; Lunkov, Andrey; Ostrovsky, Ilia

    2016-02-01

    Internal Kelvin waves (IKWs) initiated by rotation of the Earth are one of the main hydrodynamic phenomena in large stratified lakes where baroclinic Rossby radius of deformation is smaller than the horizontal scale of the lake. IKWs can be identified using the spectra of internal waves, where in the presence of IKWs, the inertial frequency is at maximum. IKWs play a rather important role in the lake's dynamics for different processes, both in the water layer and sediment, especially at the periphery of lake. Due to influence of internal waves on the sound propagation, acoustical methods can be used for estimation of behaviour of IKWs. In this paper, the spatiotemporal variability of the mid-frequency (∼1 kHz) sound field in the presence of IKWs in a deep stratified Lake Kinneret is studied using numerical simulations based on normal-mode theory. Due to the specific character of perturbation of the water layer, IKWs can cause specific variations of interference pattern, in particular, a significant shift of the sound interference pattern both in spatial and frequency domain. These shifts can be easily measured and used for reconstruction of IKW parameters.

  20. Informational connectivity: identifying synchronized discriminability of multi-voxel patterns across the brain.

    Science.gov (United States)

    Coutanche, Marc N; Thompson-Schill, Sharon L

    2013-01-01

    The fluctuations in a brain region's activation levels over a functional magnetic resonance imaging (fMRI) time-course are used in functional connectivity (FC) to identify networks with synchronous responses. It is increasingly recognized that multi-voxel activity patterns contain information that cannot be extracted from univariate activation levels. Here we present a novel analysis method that quantifies regions' synchrony in multi-voxel activity pattern discriminability, rather than univariate activation, across a timeseries. We introduce a measure of multi-voxel pattern discriminability at each time-point, which is then used to identify regions that share synchronous time-courses of condition-specific multi-voxel information. This method has the sensitivity and access to distributed information that multi-voxel pattern analysis enjoys, allowing it to be applied to data from conditions not separable by univariate responses. We demonstrate this by analyzing data collected while people viewed four different types of man-made objects (typically not separable by univariate analyses) using both FC and informational connectivity (IC) methods. IC reveals networks of object-processing regions that are not detectable using FC. The IC results support prior findings and hypotheses about object processing. This new method allows investigators to ask questions that are not addressable through typical FC, just as multi-voxel pattern analysis (MVPA) has added new research avenues to those addressable with the general linear model (GLM).

  1. Relationships of surface air temperature anomalies over Europe to persistence of atmospheric circulation patterns conducive to heat waves

    Directory of Open Access Journals (Sweden)

    J. Kyselý

    2008-04-01

    Full Text Available Heat waves are among natural hazards with the most severe consequences for human society, including pronounced mortality impacts in mid-latitudes. Recent studies have hypothesized that the enhanced persistence of atmospheric circulation may affect surface climatic extremes, mainly the frequency and severity of heat waves. In this paper we examine relationships between the persistence of the Hess-Brezowsky circulation types conducive to summer heat waves and air temperature anomalies at stations over most of the European continent. We also evaluate differences between temperature anomalies during late and early stages of warm circulation types in all seasons. Results show that more persistent circulation patterns tend to enhance the severity of heat waves and support more pronounced temperature anomalies. Recent sharply rising trends in positive temperature extremes over Europe may be related to the greater persistence of the circulation types, and if similar changes towards enhanced persistence affect other mid-latitudinal regions, analogous consequences and implications for temperature extremes may be expected.

  2. Prediction of maximum P- and S-wave amplitude distributions incorporating frequency- and distance-dependent characteristics of the observed apparent radiation patterns

    Science.gov (United States)

    Takemura, Shunsuke; Kobayashi, Manabu; Yoshimoto, Kazuo

    2016-10-01

    Frequency-dependent model of the apparent radiation pattern has been extensively incorporated into engineering and scientific applications for high-frequency seismic waves, but distance-dependent properties have not yet been fully taken into account. We investigated the unified characteristics of frequency and distance dependences in both apparent P- and S-wave radiation patterns during local crustal earthquakes. Observed distortions of the apparent P- and S-wave radiation patterns could be simply modeled by using a function of the normalized hypocentral distance, which is a product of the wave number and hypocentral distance. This behavior suggests that major cause of distortion of the apparent radiation pattern is seismic wave scattering and diffraction within the heterogeneous crust. On the basis of observed normalized hypocentral distance dependency, we proposed a method for prediction of spatial distributions of maximum P- and S-wave amplitudes. Our method incorporating normalized hypocentral distance dependence of the apparent radiation pattern reproduced the observed spatial distributions of maximum P- and S-wave amplitudes over a wide frequency and distance ranges successfully.[Figure not available: see fulltext.

  3. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...... of the physical and biochemical conditions in plant cells. As model system, we use a H(2)O(2) signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits...... which diffusion-mediated signaling is possible. We show that purely diffusive transmission of intracellular information by H(2)O(2) over a distance of 1 μm (typical distance between organelles, which may function as relay stations) is possible at frequencies well above 1 Hz, which is the highest...

  4. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian Lyngby; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca2+ ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...... of the physical and biochemical conditions in plant cells. As model system, we use a H2O2 signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits...... diffusion-mediated signaling is possible. We show that purely diffusive transmission of intracellular information by H2O2 over a distance of 1 μm (typical distance between organelles, which may function as relay stations) is possible at frequencies well above 1 Hz, which is the highest frequency observed...

  5. Temporal patterns of happiness and information in a global social network: Hedonometrics and Twitter

    CERN Document Server

    Dodds, Peter Sheridan; Kloumann, Isabel M; Bliss, Catherine A; Danforth, Christopher M

    2011-01-01

    Individual happiness is a fundamental societal metric. Normally measured through self-report, happiness has often been indirectly characterized and overshadowed by more readily quantifiable economic indicators, such as gross domestic product. Here, we use a real-time, remote-sensing, non-invasive, text-based approach---a kind of hedonometer---to uncover collective dynamical patterns of happiness levels expressed by over 50 million users in the online, global social network Twitter. With a data set comprising nearly 2.8 billion expressions involving more than 28 billion words, we explore temporal variations in happiness, as well as information levels, over time scales of hours, days, and months. Among many observations, we find a steady global happiness level, evidence of universal weekly and daily patterns of happiness and information, and that happiness and information levels are generally uncorrelated. We also extract and analyse a collection of happiness and information trends based on keywords, showing th...

  6. The Position of High Frequency Waves with Respect to the Granulation Pattern

    CERN Document Server

    Andić, Aleksandra

    2007-01-01

    High frequency velocity oscillations were observed in the spectral lines Fe I 543.45nm and 543.29nm, using 2D spectroscopy with a Fabry- Perot and speckle reconstruction, at the VTT in Tenerife. We investigate the radial component of waves with frequencies in the range 8 - 22mHz in the internetwork, network and a pore. We find that the occurrence of waves do not show any preference on location and are equally distributed over down-flows and up-flows, regardless of the activity of the observed area in the line of Fe I 543.45nm. The waves observed in the lower formed line of Fe I 543.29nm seem to appear preferentially over down-flows.

  7. Modelling the Information Seeking Patterns of Engineers and Research Scientists in an Industrial Environment.

    Science.gov (United States)

    Ellis, David; Haugan, Merete

    1997-01-01

    Engineers and research scientists at Statoil's Research Center in Trondheim, Norway were interviewed to determine information-seeking patterns. Eight characteristics were identified: surveying, chaining, monitoring, browsing, distinguishing, filtering, extracting, and ending. The results showed that although there were differences in the features…

  8. Using an ontology pattern stack to engineer a core ontology of Accounting Information Systems

    NARCIS (Netherlands)

    Blums, Ivar; Weigand, Hans

    Although the field of Accounting Information Systems (AIS) has a long tradition, there is still a lack of a widely adopted conceptualization. In this paper, The UFO ontology patterns are regarded for application by analogy and extension in the engineering of a core ontology for AIS. The new IASB

  9. Information Processing Patterns of Postsecondary American Indian/Alaska Native Students

    Science.gov (United States)

    Aragon, Steven R.

    2004-01-01

    In the last of a three-part series, this study examined the information processing patterns of postsecondary American Indian/Alaska Native students attending community and tribal colleges in the Southwest. Using a survey design, students completed the Kolb Learning Style Inventory, the Briggs and Myers Myers-Briggs Type Indicator, and the Oltman,…

  10. Walking pattern classification and walking distance estimation algorithms using gait phase information.

    Science.gov (United States)

    Wang, Jeen-Shing; Lin, Che-Wei; Yang, Ya-Ting C; Ho, Yu-Jen

    2012-10-01

    This paper presents a walking pattern classification and a walking distance estimation algorithm using gait phase information. A gait phase information retrieval algorithm was developed to analyze the duration of the phases in a gait cycle (i.e., stance, push-off, swing, and heel-strike phases). Based on the gait phase information, a decision tree based on the relations between gait phases was constructed for classifying three different walking patterns (level walking, walking upstairs, and walking downstairs). Gait phase information was also used for developing a walking distance estimation algorithm. The walking distance estimation algorithm consists of the processes of step count and step length estimation. The proposed walking pattern classification and walking distance estimation algorithm have been validated by a series of experiments. The accuracy of the proposed walking pattern classification was 98.87%, 95.45%, and 95.00% for level walking, walking upstairs, and walking downstairs, respectively. The accuracy of the proposed walking distance estimation algorithm was 96.42% over a walking distance.

  11. Using an ontology pattern stack to engineer a core ontology of Accounting Information Systems

    NARCIS (Netherlands)

    Blums, Ivar; Weigand, Hans

    2016-01-01

    Although the field of Accounting Information Systems (AIS) has a long tradition, there is still a lack of a widely adopted conceptualization. In this paper, The UFO ontology patterns are regarded for application by analogy and extension in the engineering of a core ontology for AIS. The new IASB Con

  12. Designing for social configurations: pattern languages to inform the design of ubiquitous computing

    NARCIS (Netherlands)

    Denef, S.; Opperman, R.; Keyson, D.V.

    2011-01-01

    In this paper we present our approach for informing the design of ubiquitous computing by using pattern languages of human practice. By linking ethnography and design, this approach makes it possible to tackle the social dimension of ubiquitous computing in the design processes. Adding to the existi

  13. Wave refraction and longshore current patterns along Calangute beach (Goa), west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumar, V.; Murty, C.S.; Shenoi, S.S.C.; Heblekar, A.K.

    are qualitatively assessed. The degree of refraction is less and no abnormal energy concentrations occur along this stretch. The waves after breaking give rise to many opposing flows forming circulation cells along the entire stretch. Zones of quasi-permanent rip...

  14. Efficient computation of steady, 3D water-wave patterns, application to hovercraft-type flows

    NARCIS (Netherlands)

    M.R. Lewis; B. Koren (Barry)

    2002-01-01

    textabstractNumerical methods for the computation of stationary free surfaces is the subject of much current research in computational engineering. The present report is directed towards free surfaces in maritime engineering. Of interest here are the long steady waves generated by hovercraft and

  15. Wave refraction patterns and their role in sediment redistribution along South Konkan, Maharashtra, India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Angusamy, N.; Rajamanickam, G.V.

    to the south is very irregular and indented, and is attributed to a submergent type (Ahmed, 1972; Wagle, 1989; Sukthankar, 1995). The area is characterized by the presence of wave cut ter- races, headlands, stacks, tombolos, tidal flats, cliffs and abandoned...

  16. Efficient computation of steady, 3D water-wave patterns, application to hovercraft-type flows

    NARCIS (Netherlands)

    Lewis, M.R.; Koren, B.

    2002-01-01

    Numerical methods for the computation of stationary free surfaces is the subject of much current research in computational engineering. The present report is directed towards free surfaces in maritime engineering. Of interest here are the long steady waves generated by hovercraft and ships, the grav

  17. Patterns of Knowledge Sharing and Knowledge Creation in New Information Environments

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Meyer, Kirsten

    2006-01-01

    and creation processes. The aim is to obtain a deeper comprehension of which factors determine whether the use of information technology becomes a success or a failure in relation to knowledge sharing and creation. The paper is based on three previous studies investigating the use of information technology......Do the knowledge sharing and creation processes in collaborating groups benefit from the use of new information environments or are the environments rather inhibitive to the development of these processes? A number of different studies have shown quite varied results when it comes to appraising...... the importance and value of using new information technology in knowledge sharing and creation processes. In this paper we will try to unveil the patterns appearing in the use of new information environment and the users' understanding of the significance of using information technology in knowledge sharing...

  18. An exploration of search patterns and credibility issues among older adults seeking online health information.

    Science.gov (United States)

    Robertson-Lang, Laura; Major, Sonya; Hemming, Heather

    2011-12-01

    The Internet is an important resource for health information, among younger and older people alike. Unfortunately, there are limitations associated with online health information. Research is needed on the quality of information found online and on whether users are being critical consumers of the information they find. Also, there is a need for research investigating online use among adults aged 65 and over - a rapidly growing demographic of Internet users. The current study presents important descriptive data about the search patterns of older adults seeking online health information, the types of health topics they research, and whether they consider credibility issues when retrieving online health information. A comparison is also made between search strategies used in printed text and hypertext environments. The results, which have implications with respect to credibility issues, highlight the need to increase awareness about critical searching skills among older adult Internet users.

  19. Dynamic and resuspension by waves and sedimentation pattern definition in low energy environments: guaíba lake (Brazil

    Directory of Open Access Journals (Sweden)

    João Luiz Nicolodi

    2013-03-01

    Full Text Available Little research has been undertaken into sediment dynamics in lakes, and most of it only analyses particular aspects such as the texture of the sediments. In this study, the characteristics of the wave field in Guaíba Lake are investigated. The parameters significant wave height (Hs, period (T and direction of wave propagation are examined together with their relation to the resuspension of sediments at the bottom. For this purpose, the mathematical model SWAN (Simulating Waves Nearshore has been validated and employed. The results pointed out that the highest waves modeled reached 0.55 m at a few points in the lake, particularly when winds were blowing from the S and SE quadrants with an intensity over 7 m.s-1. Generally speaking, waves follow wind intensity and direction patterns, and reach maximum height in about 1 to 2 hours after wind speed peaks. Whenever winds were stronger, waves took some 2 hours to reach 0.10 m. However, with weak to moderate winds, the waves took around 3 hours to achieve this value in significant wave height. In addition to speed and direction, wind regularity proved relevant in generating and propagating waves on Lake Guaíba. In conclusion the lake's sediment environments were mapped and classified as follows: 1 Depositional Environments (51% of the lake; 2 Transitional Environments (41%; and 3 Erosional or Non-Depositional Environments (8%. As a contribution to the region's environmental management, elements have been created relating to the concentration of suspended particulate matter.Pesquisas referentes à dinâmica sedimentar em lagos são escassas e a maioria trata da distribuição e textura dos sedimentos, sendo raras aquelas que fazem menção ao padrão de ondas e suas relações com a ressuspensão destes sedimentos e suas consequências. Este trabalho analisa as características das ondas incidentes no Lago Guaíba (Brasil por meio da utilização do SWAN (Simulating Waves Nearshore e suas rela

  20. Computation of antenna pattern correlation and MIMO performance by means of surface current distribution and spherical wave theory

    Directory of Open Access Journals (Sweden)

    O. Klemp

    2006-01-01

    Full Text Available In order to satisfy the stringent demand for an accurate prediction of MIMO channel capacity and diversity performance in wireless communications, more effective and suitable models that account for real antenna radiation behavior have to be taken into account. One of the main challenges is the accurate modeling of antenna correlation that is directly related to the amount of channel capacity or diversity gain which might be achieved in multi element antenna configurations. Therefore spherical wave theory in electromagnetics is a well known technique to express antenna far fields by means of a compact field expansion with a reduced number of unknowns that was recently applied to derive an analytical approach in the computation of antenna pattern correlation. In this paper we present a novel and efficient computational technique to determine antenna pattern correlation based on the evaluation of the surface current distribution by means of a spherical mode expansion.

  1. Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

    Science.gov (United States)

    Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

    2015-10-01

    The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (poverlay pattern was between 2 and 3. Emax with optimal cutoff at 45.1 kPa showed the highest Az value, sensitivity, specificity and accuracy among other quantitative SWE parameters (poverlay pattern and pathology (poverlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Measuring information interactions on the ordinal pattern of stock time series.

    Science.gov (United States)

    Zhao, Xiaojun; Shang, Pengjian; Wang, Jing

    2013-02-01

    The interactions among time series as individual components of complex systems can be quantified by measuring to what extent they exchange information among each other. In many applications, one focuses not on the original series but on its ordinal pattern. In such cases, trivial noises appear more likely to be filtered and the abrupt influence of extreme values can be weakened. Cross-sample entropy and inner composition alignment have been introduced as prominent methods to estimate the information interactions of complex systems. In this paper, we modify both methods to detect the interactions among the ordinal pattern of stock return and volatility series, and we try to uncover the information exchanges across sectors in Chinese stock markets.

  3. Exploring the complex pattern of information spreading in online blog communities.

    Science.gov (United States)

    Pei, Sen; Muchnik, Lev; Tang, Shaoting; Zheng, Zhiming; Makse, Hernán A

    2015-01-01

    Information spreading in online social communities has attracted tremendous attention due to its utmost practical values in applications. Despite that several individual-level diffusion data have been investigated, we still lack the detailed understanding of the spreading pattern of information. Here, by comparing information flows and social links in a blog community, we find that the diffusion processes are induced by three different spreading mechanisms: social spreading, self-promotion and broadcast. Although numerous previous studies have employed epidemic spreading models to simulate information diffusion, we observe that such models fail to reproduce the realistic diffusion pattern. In respect to users behaviors, strikingly, we find that most users would stick to one specific diffusion mechanism. Moreover, our observations indicate that the social spreading is not only crucial for the structure of diffusion trees, but also capable of inducing more subsequent individuals to acquire the information. Our findings suggest new directions for modeling of information diffusion in social systems, and could inform design of efficient propagation strategies based on users behaviors.

  4. Exploring the complex pattern of information spreading in online blog communities.

    Directory of Open Access Journals (Sweden)

    Sen Pei

    Full Text Available Information spreading in online social communities has attracted tremendous attention due to its utmost practical values in applications. Despite that several individual-level diffusion data have been investigated, we still lack the detailed understanding of the spreading pattern of information. Here, by comparing information flows and social links in a blog community, we find that the diffusion processes are induced by three different spreading mechanisms: social spreading, self-promotion and broadcast. Although numerous previous studies have employed epidemic spreading models to simulate information diffusion, we observe that such models fail to reproduce the realistic diffusion pattern. In respect to users behaviors, strikingly, we find that most users would stick to one specific diffusion mechanism. Moreover, our observations indicate that the social spreading is not only crucial for the structure of diffusion trees, but also capable of inducing more subsequent individuals to acquire the information. Our findings suggest new directions for modeling of information diffusion in social systems, and could inform design of efficient propagation strategies based on users behaviors.

  5. Instantaneous information propagation in free flow, synchronized flow, stop-and-go waves in a cellular automaton model

    Institute of Scientific and Technical Information of China (English)

    Jiang Rui; Jin Wen-Long; Wu Qing-Song

    2008-01-01

    Recently, a number of efforts are underway to investigate inter-vehicle communications (IVC). This paper studies the instantaneous information propagation behaviours based on IVC in three different traffic situations (free flow,synchronized flow and stop-and-go waves) in a cellular automaton model. It is shown that different behaviours appear in stop-and-go waves from those in free flow and synchronized flow. While the distribution of Multi-hop Communication Distance (MhCD) is either exponential or uniform in free flow and synchronized flow, the distribution of MhCD is either exponential or with a single peak in stop-and-go waves.

  6. Application of power spectra patterns in Fourier transform square wave voltammetry to evaluate electrode kinetics of surface-confined proteins.

    Science.gov (United States)

    Fleming, Barry D; Barlow, Nicola L; Zhang, Jie; Bond, Alan M; Armstrong, Fraser A

    2006-05-01

    This paper describes an application of Fourier transform (FT) voltammetry that provides a quantitative evaluation of the electron-transfer kinetics of protein molecules attached to electrode surfaces. The potential waveform applied in these experiments consists of a large-amplitude square wave of frequency f superimposed onto the traditional triangular voltage used in dc cyclic voltammetry. The resultant current-time response, when Fourier transformed into the frequency domain, provides patterns of data at the even harmonic frequencies that arise from nonlinearity in the Faradaic response. These even harmonic contributions are ideally suited for kinetic evaluation of electron-transfer processes because they are highly selective to quasi-reversible behavior (insensitive to reversible or irreversible processes) and almost devoid of background charging current. Inverse FT methods can then be used to provide the wave shapes of the dc as well as the ac voltammetric components and other characteristics employed to detect the level of nonideality present relative to theoretical models based upon noninteracting surface-confined molecules. The new form of data evaluation has been applied to the electron-transfer properties of a typical biological electron carrier, the blue copper protein azurin, immobilized on polycrystalline gold electrodes modified with self-assembled monolayers of different length alkanethiols. Details of the electrode kinetics (rates of electron transfer, dispersion, and charge-transfer coefficients) as a function of alkanethiol, apparent surface coverage, and capacitance are all deduced from the square wave (FT-inverse FT) protocol, and the implications of these findings are considered.

  7. Pattern formation of coupled spiral waves in bilayer systems: rich dynamics and high-frequency dominance.

    Science.gov (United States)

    Nie, Haichun; Gao, Jihua; Zhan, Meng

    2011-11-01

    The interaction of two spiral waves with independent frequencies in a bilayer oscillatory medium (one spiral in each layer) and with a symmetric coupling e is studied. If the spirals have different frequencies, the faster spiral is unaffected by the slower one, and the slower can show a variety of behaviors, which depend on e and include, in order of increasing e, phase drifting, amplitude modulation, amplitude domination, and phase synchronization. This high-frequency dominance, the asymmetric driving-response effect under the condition of a symmetric coupling, is generic and independent of whether the coupled spiral waves are outwardly rotating or inwardly rotating spirals. If the spirals have identical frequencies, they may even show complete synchronization, parallel drift, or circular drift, depending on the relative rotation direction of the two spirals and their initial separation distance. Comparisons with coupled spirals in monolayer media, previous works on coupled spirals in bilayer systems, and coupled phase oscillators are made.

  8. Wave-induced nearshore flow patterns in the vicinity of Cochin harbour, India

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Vethamony, P.; Murty, C.S.

    of a sheared cellular flow pattern with clockwise and anti-clockwise rotations exhibiting noticeable spatial variation. Field studies reveal a southerly littoral current during most of the year. A conceptual model is presented to explain the sediment...

  9. Information retrieval patterns and needs among practicing general surgeons: a statewide experience.

    Science.gov (United States)

    Shelstad, K R; Clevenger, F W

    1996-10-01

    Information retrieval has progressed from a reliance on traditional print sources to the modern era of computer databases and online networks. Surgeons, many from remote areas not served by professional medical libraries, must develop and maintain skills in information retrieval and management in both electronic and standard formats. One hundred thirty-three New Mexico general surgeons were surveyed to identify their information-seeking patterns in five areas: retrieval purposes, retrieval sources, barriers to access, techniques used, and continuing education needs. Ninety-nine (74.4%) surgeons responded to the survey. Ninety-five percent utilize professional meetings, the medical literature, and physician colleagues as information sources. Only 17% utilize the outreach services of the state's only medical school library. Common retrieval barriers were practice demands (71%), isolation from medical schools (30%), computer illiteracy (28%), and rural environment (25%). Continuing education topics related to information management would be valuable to 61% of the surgeons. Sixty-nine percent believe their current ability to access biomedical information is adequate, despite most frequently accessing their personal libraries for information related to decision-making or patient management. These data suggest that, despite significant information needs, surgeons have not embraced newer forms of information retrieval. It is imperative that surgeons acquire and maintain modern information retrieval skills as a means of remaining up-to-date in their profession. Professional surgical organizations and medical librarians should collaborate on these continuing education ventures.

  10. Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns

    Directory of Open Access Journals (Sweden)

    Gareth J. Williams

    2013-05-01

    Full Text Available Kingman Reef and Palmyra Atoll in the central Pacific are among the most remote coral reefs on the planet. Here we describe spatial patterns in their benthic communities across reef habitats and depths, and consider these in the context of oceanographic gradients. Benthic communities at both locations were dominated by calcifying organisms (54–86% cover, namely hard corals (20–74% and crustose coralline algae (CCA (10–36%. While turf algae were relatively common at both locations (8–22%, larger fleshy macroalgae were virtually absent at Kingman (<1% and rare at Palmyra (0.7–9.3%. Hard coral cover was higher, but with low diversity, in more sheltered habitats such as Palmyra’s backreef and Kingman’s patch reefs. Almost exclusive dominance by slow-growing Porites on Kingman’s patch reefs provides indirect evidence of competitive exclusion, probably late in a successional sequence. In contrast, the more exposed forereef habitats at both Kingman and Palmyra had higher coral diversity and were characterized by fast-growing corals (e.g., Acropora and Pocillopora, indicative of more dynamic environments. In general at both locations, soft coral cover increased with depth, likely reflecting increasingly efficient heterotrophic abilities. CCA and fleshy macroalgae cover decreased with depth, likely due to reduced light. Cover of other calcified macroalgae, predominantly Halimeda, increased with depth. This likely reflects the ability of many calcifying macroalgae to efficiently harvest light at deeper depths, in combination with an increased nutrient supply from upwelling promoting growth. At Palmyra, patterns of hard coral cover with depth were inconsistent, but cover peaked at mid-depths at Kingman. On Kingman’s forereef, benthic community composition was strongly related to wave energy, with hard coral cover decreasing and becoming more spatially clustered with increased wave energy, likely as a result of physical damage leading to

  11. Influence of a Propagating Megahertz Surface Acoustic Wave on the Pattern Deposition of Solute Mass off an Evaporating Solution.

    Science.gov (United States)

    Mhatre, Sameer; Zigelman, Anna; Abezgauz, Ludmila; Manor, Ofer

    2016-09-20

    We study the influence of a megahertz Rayleigh surface acoustic wave (SAW), propagating in a solid substrate, on the pattern deposition of a solute mass off an evaporating solution. An experimental procedure, where a film of a solution undergoes a controlled evaporation in a chamber, shows that the SAW alters the state of the pattern deposition. Increasing the power of the SAW supports an increase in the density of the deposited patterns. Beyond threshold conditions, the deposited patterns merge and we observe the deposition of a solid film. A simplified theory suggests that the SAW deforms the geometry of the film, which is predominantly governed by the capillary stress. The deformation of the film taking place alongside with the evaporation of the solution increases the concentration near the pinned three phase contact line at the front of the film, which is closer to the source of the SAW, on the expense of the concentration at the rear. The increased concentration translates to the deposition of solute mass over an increased area near the front of the film, which explains the experimental observation.

  12. Anisotropies of Gravitational-Wave Standard Sirens as a New Cosmological Probe without Redshift Information.

    Science.gov (United States)

    Namikawa, Toshiya; Nishizawa, Atsushi; Taruya, Atsushi

    2016-03-25

    Gravitational waves (GWs) from compact binary stars at cosmological distances are promising and powerful cosmological probes, referred to as the GW standard sirens. With future GW detectors, we will be able to precisely measure source luminosity distances out to a redshift z∼5. To extract cosmological information, previously proposed cosmological studies using the GW standard sirens rely on source redshift information obtained through an extensive electromagnetic follow-up campaign. However, the redshift identification is typically time consuming and rather challenging. Here, we propose a novel method for cosmology with the GW standard sirens free from the redshift measurements. Utilizing the anisotropies of the number density and luminosity distances of compact binaries originated from the large-scale structure, we show that, once GW observations will be well established in the future, (i) these anisotropies can be measured even at very high redshifts (z≥2), where the identification of the electromagnetic counterpart is difficult, (ii) the expected constraints on the primordial non-Gaussianity with the Einstein Telescope would be comparable to or even better than the other large-scale structure probes at the same epoch, and (iii) the cross-correlation with other cosmological observations is found to have high-statistical significance, providing additional cosmological information at very high redshifts.

  13. Adaptive intesration of local resion information to detect fine-scale brain activity patterns

    Institute of Scientific and Technical Information of China (English)

    ZHEN ZongLei; TIAN Jie; ZHANG Hui

    2008-01-01

    With the rapid development of functional magnetic resonance imaging (fMRI) technology, the spatial resolution of fMRI data is continuously growing. This pro-vides us the possibility to detect the fine-scale patterns of brain activities. The es-tablished univariate and multivariate methods to analyze fMRI data mostly focus on detecting the activation blobs without considering the distributed fine-scale pat-terns within the blobs. To improve the sensitivity of the activation detection, in this paper, multivariate statistical method and univariate statistical method are com-bined to discover the fine-grained activity patterns. For one voxel in the brain, a local homogenous region is constructed. Then, time courses from the local ho-mogenous region are integrated with multivariate statistical method. Univariate statistical method is finally used to construct the interests of statistic for that voxel. The approach has explicitly taken into account the structures of both activity pat-terns and existing noise of local brain regions. Therefore, it could highlight the fine-scale activity patterns of the local regions. Experiments with simulated and real fMRI data demonstrate that the proposed method dramatically increases the sensitivity of detection of fine-scale brain activity patterns which contain the subtle information about experimental conditions.

  14. Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.

    Directory of Open Access Journals (Sweden)

    Susanne H Landis

    Full Text Available Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle as a host and its digenean trematode parasite (Cryptocotyle lingua. In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming.

  15. Patterns of information behavior and prostate cancer knowledge among African-American men.

    Science.gov (United States)

    Ross, Levi; Dark, Tyra; Orom, Heather; Underwood, Willie; Anderson-Lewis, Charkarra; Johnson, Jarrett; Erwin, Deborah O

    2011-12-01

    The purposes of this study are to explore cancer information acquisition patterns among African-American men and to evaluate relationships between information acquisition patterns and prostate cancer prevention and control knowledge. A random sample of 268 men participated in a statewide interviewer-administered, telephone survey. Men classified as non-seekers, non-medical source seekers, and medical source seekers of prostate cancer information differed on household income, level of education, and beliefs about personal risk for developing prostate cancer. Results from multiple regression analysis indicated that age, education, and information-seeking status were associated with overall levels of prostate cancer knowledge. Results from logistic regression analyses indicated that men who included physicians as one of many information resources (medical source seekers) had superior knowledge over non-seekers and non-medical source seekers on 33% of individual knowledge details. The findings emphasize the need to connect lower-income and lower-educated African-American men to physicians as a source of prostate cancer control information.

  16. GeoPAT: A toolbox for pattern-based information retrieval from large geospatial databases

    Science.gov (United States)

    Jasiewicz, Jarosław; Netzel, Paweł; Stepinski, Tomasz

    2015-07-01

    Geospatial Pattern Analysis Toolbox (GeoPAT) is a collection of GRASS GIS modules for carrying out pattern-based geospatial analysis of images and other spatial datasets. The need for pattern-based analysis arises when images/rasters contain rich spatial information either because of their very high resolution or their very large spatial extent. Elementary units of pattern-based analysis are scenes - patches of surface consisting of a complex arrangement of individual pixels (patterns). GeoPAT modules implement popular GIS algorithms, such as query, overlay, and segmentation, to operate on the grid of scenes. To achieve these capabilities GeoPAT includes a library of scene signatures - compact numerical descriptors of patterns, and a library of distance functions - providing numerical means of assessing dissimilarity between scenes. Ancillary GeoPAT modules use these functions to construct a grid of scenes or to assign signatures to individual scenes having regular or irregular geometries. Thus GeoPAT combines knowledge retrieval from patterns with mapping tasks within a single integrated GIS environment. GeoPAT is designed to identify and analyze complex, highly generalized classes in spatial datasets. Examples include distinguishing between different styles of urban settlements using VHR images, delineating different landscape types in land cover maps, and mapping physiographic units from DEM. The concept of pattern-based spatial analysis is explained and the roles of all modules and functions are described. A case study example pertaining to delineation of landscape types in a subregion of NLCD is given. Performance evaluation is included to highlight GeoPAT's applicability to very large datasets. The GeoPAT toolbox is available for download from

  17. Laser shock wave assisted patterning on NiTi shape memory alloy surfaces

    Science.gov (United States)

    Seyitliyev, Dovletgeldi; Li, Peizhen; Kholikov, Khomidkhodza; Grant, Byron; Karaca, Haluk E.; Er, Ali O.

    2017-02-01

    An advanced direct imprinting method with low cost, quick, and less environmental impact to create thermally controllable surface pattern using the laser pulses is reported. Patterned micro indents were generated on Ni50Ti50 shape memory alloys (SMA) using an Nd:YAG laser operating at 1064 nm combined with suitable transparent overlay, a sacrificial layer of graphite, and copper grid. Laser pulses at different energy densities which generates pressure pulses up to 10 GPa on the surface was focused through the confinement medium, ablating the copper grid to create plasma and transferring the grid pattern onto the NiTi surface. Scanning electron microscope (SEM) and optical microscope images of square pattern with different sizes were studied. One dimensional profile analysis shows that the depth of the patterned sample initially increase linearly with the laser energy until 125 mJ/pulse where the plasma further absorbs and reflects the laser beam. In addition, light the microscope image show that the surface of NiTi alloy was damaged due to the high power laser energy which removes the graphite layer.

  18. A scenario-based study on information flow and collaboration patterns in disaster management.

    Science.gov (United States)

    Sagun, Aysu; Bouchlaghem, Dino; Anumba, Chimay J

    2009-04-01

    Disaster management (DM) is a continuous, highly collaborative process involving governments, DM organisations, responders, the construction sector, and the general public. Most research approaches to DM include the development of information and communication technologies (ICT) to support the collaboration process rather than the creation of a collaboration process to provide information flows and patterns. An Intelligent Disaster Collaboration System (IDCS) is introduced in this paper as a conceptual model to integrate ICT into DM and the mitigation process and to enhance collaboration. The framework is applicable to the collaboration process at the local, regional and national levels. Within this context, the deployment of ICT tools in DM is explored and scenario-based case studies on flooding and terrorism--examples of natural and human-induced disasters, respectively--are presented. Conclusions are drawn regarding the differences found in collaboration patterns and ICT used during natural and human-induced disasters and the differences between currently available ICT and proposed ICT.

  19. Using visual information analysis to explore complex patterns in the activity of designers

    DEFF Research Database (Denmark)

    Cash, Philip; Stanković, Tino; Štorga, Mario

    2014-01-01

    the temporality of interrelations between interlinked variables and, as such, can be applied to a range of datasets. By providing a statistical analysis of the networks’ growth the proposed method allows for the modelling of complex patterns of activity. Throughout, the method is demonstrated with respect......The analysis of complex interlinked datasets poses a significant problem for design researchers. This is addressed by proposing an information visualisation method for analysing patterns of design activity, qualitatively and quantitatively, with respect to time. This method visualises...... to a fully realised example of information seeking activity. The core contribution of the proposed method is in supporting the analysis of activity with respect to both macro and micro level temporal interactions between variables....

  20. On Assisting a Visual-Facial Affect Recognition System with Keyboard-Stroke Pattern Information

    Science.gov (United States)

    Stathopoulou, I.-O.; Alepis, E.; Tsihrintzis, G. A.; Virvou, M.

    Towards realizing a multimodal affect recognition system, we are considering the advantages of assisting a visual-facial expression recognition system with keyboard-stroke pattern information. Our work is based on the assumption that the visual-facial and keyboard modalities are complementary to each other and that their combination can significantly improve the accuracy in affective user models. Specifically, we present and discuss the development and evaluation process of two corresponding affect recognition subsystems, with emphasis on the recognition of 6 basic emotional states, namely happiness, sadness, surprise, anger and disgust as well as the emotion-less state which we refer to as neutral. We find that emotion recognition by the visual-facial modality can be aided greatly by keyboard-stroke pattern information and the combination of the two modalities can lead to better results towards building a multimodal affect recognition system.

  1. A Peculiar Velocity Pattern in and near the Leading Sunspot of NOAA 10781: Wave Refraction by Large-Scale Magnetic Fields?

    CERN Document Server

    Beck, C

    2010-01-01

    I report observations of unusually strong photospheric and chromospheric velocity oscillations in and near the leading sunspot of NOAA 10781 on 03 July 2005. I investigate an impinging wave as a possible origin of the velocity pattern, and the changes of the wave after the passage through the magnetic fields of the sunspot. The wave pattern found consists of a wave with about 3 Mm apparent wavelength that propagates towards the sunspot. This wave seems to trigger oscillations inside the sunspot's umbra, which originate from a location inside the penumbra on the side of the impinging wave. The wavelength decreases and the velocity amplitude increases by an order of magnitude in the chromospheric layers inside the sunspot. On the side of the sunspot opposite to the impinging plane wave, circular wave fronts centered on the umbra are seen propagating away from the sunspot outside its outer white-light boundary. They lead to a peculiar ring structure around the sunspot, which is visible in both velocity and inten...

  2. Structural information in two-dimensional patterns: entropy convergence and excess entropy.

    Science.gov (United States)

    Feldman, David P; Crutchfield, James P

    2003-05-01

    We develop information-theoretic measures of spatial structure and pattern in more than one dimension. As is well known, the entropy density of a two-dimensional configuration can be efficiently and accurately estimated via a converging sequence of conditional entropies. We show that the manner in which these conditional entropies converge to their asymptotic value serves as a measure of global correlation and structure for spatial systems in any dimension. We compare and contrast entropy convergence with mutual-information and structure-factor techniques for quantifying and detecting spatial structure.

  3. Integration of Information Patterns in the Modeling and Design of Mobility Management Services

    OpenAIRE

    Keimer, Alexander; Laurent-Brouty, Nicolas; Farokhi, Farhad; Signargout, Hippolyte; Cvetkovic, Vladimir; Bayen, Alexandre M.; Johansson, Karl H.

    2017-01-01

    Over the last decade, the rise of the mobile internet and the usage of mobile devices has enabled ubiquitous traffic information. With the increased adoption of specific smartphone applications, the number of users of routing applications has become large enough to disrupt traffic flow patterns in a significant manner. Similarly, but at a slightly slower pace, novel services for freight transportation and city logistics improve the efficiency of goods transportation and change the use of road...

  4. Investigating Chinese Migrants’ Information-Seeking Patterns in Canada: Media Selection and Language Preference

    Directory of Open Access Journals (Sweden)

    Yuping Mao

    2015-12-01

    Full Text Available Taking a quantitative approach, this research surveyed Chinese migrants in Canada regarding channels they rely on to seek various information. This research also investigates how Chinese migrants’ preferences of channels correlate with their intercultural sensitivity level. Chinese migrants prefer Chinese newspapers and websites for government/policy information and life information rather than English newspapers and websites. However, they use English newspapers and websites more frequently for job and career development information. Overall, English television and radio are more frequently used by Chinese migrants than Chinese television and radio broadcasts. The intercultural sensitivity levels of Chinese migrants have a positive correlation with their frequencies of using English information resources, including government websites, English newspapers, English non-government websites, government officers, personal non-Chinese social networks, and English television and radio. Findings of this research suggest that Chinese ethnic media play an important role in Chinese migrants’ information-seeking behaviours and patterns in Canada. On one hand, government and other organizations can reach the Chinese migrant community through information diffusion in Chinese ethnic media. On the other hand, Chinese migrants should make an active effort to improve their English proficiency and intercultural communication sensitivity to better integrate themselves into the Canadian society. A more balanced approach of seeking information from English and Chinese media sources could be more beneficial for Chinese migrants.

  5. Anisotropies of gravitational-wave standard sirens as a new cosmological probe without redshift information

    Science.gov (United States)

    Nishizawa, Atsushi; Namikawa, Toshiya; Taruya, Atsushi

    2016-03-01

    Gravitational waves (GWs) from compact binary stars at cosmological distances are promising and powerful cosmological probes, referred to as the GW standard sirens. With future GW detectors, we will be able to precisely measure source luminosity distances out to a redshift z 5. To extract cosmological information, previous studies using the GW standard sirens rely on source redshift information obtained through an extensive electromagnetic follow-up campaign. However, the redshift identification is typically time-consuming and rather challenging. Here we propose a novel method for cosmology with the GW standard sirens free from the redshift measurements. Utilizing the anisotropies of the number density and luminosity distances of compact binaries originated from the large-scale structure, we show that (i) this anisotropies can be measured even at very high-redshifts (z = 2), (ii) the expected constraints on the primordial non-Gaussianity with Einstein Telescope would be comparable to or even better than the other large-scale structure probes at the same epoch, (iii) the cross-correlation with other cosmological observations is found to have high-statistical significance. A.N. was supported by JSPS Postdoctoral Fellowships for Research Abroad No. 25-180.

  6. A NUMERICAL APPLICATION TO PREDICT THE RESISTANCE AND WAVE PATTERN OF KRISO CONTAINER SHIP

    Directory of Open Access Journals (Sweden)

    Yavuz Hakan Ozdemir

    2016-06-01

    Full Text Available In this study, the computational results for KRISO Container Ship (KCS are presented. CFD analyses are performed to simulate free surface flow around KCS by using RANS approach with success. Also the complicated turbulent flow zone behind the ship is well simulated. The RANS equations and the non-linear free surface boundary conditions are discretized by means of a finite volume scheme. The numerical methodology is found to be appropriate for simulating the turbulent flow around a ship in order to estimate ship total resistance and free surface. By the numerical results, total resistance is calculated for the ship model and the result is satisfactory with regard to the experimental one. As a result of well captured free surface, the wave elevation on/around the hull is compared with the experimental results.

  7. Spatiotemporal pattern in somitogenesis: a non-Turing scenario with wave propagation.

    Science.gov (United States)

    Nagahara, Hiroki; Ma, Yue; Takenaka, Yoshiko; Kageyama, Ryoichiro; Yoshikawa, Kenichi

    2009-08-01

    Living organisms maintain their lives under far-from-equilibrium conditions by creating a rich variety of spatiotemporal structures in a self-organized manner, such as temporal rhythms, switching phenomena, and development of the body. In this paper, we focus on the dynamical process of morphogens in somitogenesis in mice where propagation of the gene expression level plays an essential role in creating the spatially periodic patterns of the vertebral columns. We present a simple discrete reaction-diffusion model which includes neighboring interaction through an activator, but not diffusion of an inhibitor. We can produce stationary periodic patterns by introducing the effect of spatial discreteness to the field. Based on the present model, we discuss the underlying physical principles that are independent of the details of biomolecular reactions. We also discuss the framework of spatial discreteness based on the reaction-diffusion model in relation to a cellular array, by comparison with an actual experimental observation.

  8. Spatiotemporal pattern in somitogenesis: A non-Turing scenario with wave propagation

    Science.gov (United States)

    Nagahara, Hiroki; Ma, Yue; Takenaka, Yoshiko; Kageyama, Ryoichiro; Yoshikawa, Kenichi

    2009-08-01

    Living organisms maintain their lives under far-from-equilibrium conditions by creating a rich variety of spatiotemporal structures in a self-organized manner, such as temporal rhythms, switching phenomena, and development of the body. In this paper, we focus on the dynamical process of morphogens in somitogenesis in mice where propagation of the gene expression level plays an essential role in creating the spatially periodic patterns of the vertebral columns. We present a simple discrete reaction-diffusion model which includes neighboring interaction through an activator, but not diffusion of an inhibitor. We can produce stationary periodic patterns by introducing the effect of spatial discreteness to the field. Based on the present model, we discuss the underlying physical principles that are independent of the details of biomolecular reactions. We also discuss the framework of spatial discreteness based on the reaction-diffusion model in relation to a cellular array, by comparison with an actual experimental observation.

  9. Variability in wave refraction and resultant nearshore current patterns: Exposed versus sheltered beaches along north Karnataka, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Veerayya, M.; Pankajakshan, T.

    For predominant waves approaching from directions varying between SW and WNW and periods varying from 6 to 11 sec, the refraction function (Kd) shows amplification of wave heights resulting in concentration of wave energy on headlands and reduction...

  10. Planar ESPAR Array Design with Nonsymmetrical Pattern by Means of Finite-Element Method, Domain Decomposition, and Spherical Wave Expansion

    Directory of Open Access Journals (Sweden)

    Jesús García

    2012-01-01

    Full Text Available The application of a 3D domain decomposition finite-element and spherical mode expansion for the design of planar ESPAR (electronically steerable passive array radiator made with probe-fed circular microstrip patches is presented in this work. A global generalized scattering matrix (GSM in terms of spherical modes is obtained analytically from the GSM of the isolated patches by using rotation and translation properties of spherical waves. The whole behaviour of the array is characterized including all the mutual coupling effects between its elements. This procedure has been firstly validated by analyzing an array of monopoles on a ground plane, and then it has been applied to synthesize a prescribed radiation pattern optimizing the reactive loads connected to the feeding ports of the array of circular patches by means of a genetic algorithm.

  11. A Comprehensive Study of Fracture Patterns and Densities in The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peter E. Malin; Eylon Shalev; Min Lou; Silas M. Simiyu; Anastasia Stroujkova; Windy McCausland

    2004-02-24

    In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be possible to reduce the cost of geothermal power development with the targeting of high production geothermal wells. (3) The results of the project having been transferred to both US based and international geothermal research and exploration agencies and concerns by several published papers and meeting presentations, and through the distribution of the data handling and other software codes we developed.

  12. Numerical Prediction of Wave Patterns Due to Motion of 3D Bodies by Kelvin-Havelock Sources

    Directory of Open Access Journals (Sweden)

    Ghassemi Hassan

    2016-12-01

    Full Text Available This paper discusses the numerical evaluation of the hydrodynamic characteristics of submerged and surface piercing moving bodies. Generally, two main classes of potential methods are used for hydrodynamic characteristic analysis of steady moving bodies which are Rankine and Kelvin-Havelock singularity distribution. In this paper, the Kelvin- Havelock sources are used for simulating the moving bodies and then free surface wave patterns are obtained. Numerical evaluation of potential distribution of a Kelvin-Havelock source is completely presented and discussed. Numerical results are calculated and presented for a 2D cylinder, single source, two parallel moving source, sphere, ellipsoid and standard Wigley hull in different situation that show acceptable agreement with results of other literatures or experiments.

  13. 77 FR 28566 - Notice of Request for a New Information Collection (Food Safety Education Campaign-Post-Wave...

    Science.gov (United States)

    2012-05-15

    ... From the Federal Register Online via the Government Publishing Office #0; #0;Notices #0; Federal... seeking approval of a new information collection to help evaluate the impact of the Food Safety Education... prevention behaviors. The post-wave survey will be fielded approximately 12 months following launch of...

  14. Oscillations and uniaxial mechanochemical waves in a model of an active poroelastic medium: Application to deformation patterns in protoplasmic droplets of Physarum polycephalum

    Science.gov (United States)

    Alonso, Sergio; Strachauer, Ulrike; Radszuweit, Markus; Bär, Markus; Hauser, Marcus J. B.

    2016-04-01

    Self-organization in cells often manifests itself in oscillations and waves. Here, we address deformation waves in protoplasmic droplets of the plasmodial slime mould Physarum polycephalum by modelling and experiments. In particular, we extend a one-dimensional model that considered the cell as a poroelastic medium, where active tension caused mechanochemical waves that were regulated by an inhibitor (Radszuweit et al., 2013). Our extension consists of a simple, qualitative chemical reaction-diffusion model (Brusselator) that describes the regulation of the inhibitor by another biochemical species. The biochemical reaction enhances the formation of mechanochemical waves if the reaction rates and input concentrations are near or inside an oscillatory regime. The period of the waves is found to be controlled by the characteristic oscillation period, whereas their wavelength is set by mechanical parameters. The model also allows for a systematic study of the chemical activity at the onset of mechanochemical waves. We also present examples for pattern formation in protoplasmic droplets of Physarum polycephalum including global oscillations where the central region of the droplets is in antiphase to the boundary zone, as well as travelling and standing wave-like uniaxial patterns. Finally, we apply our model to reproduce these experimental results by identifying the active tension inhibitor with the intracellular calcium concentration in the Physarum droplets and by using parameter values from mechanical experiments, respectively knowledge about the properties of calcium oscillations in Physarum. The simulation results are then found to be in good agreement with the experimental observations.

  15. How events determine spreading patterns: information transmission via internal and external influences on social networks

    Science.gov (United States)

    Liu, Chuang; Zhan, Xiu-Xiu; Zhang, Zi-Ke; Sun, Gui-Quan; Hui, Pak Ming

    2015-11-01

    Recently, information transmission models motivated by the classical epidemic propagation, have been applied to a wide-range of social systems, generally assume that information mainly transmits among individuals via peer-to-peer interactions on social networks. In this paper, we consider one more approach for users to get information: the out-of-social-network influence. Empirical analyzes of eight typical events’ diffusion on a very large micro-blogging system, Sina Weibo, show that the external influence has significant impact on information spreading along with social activities. In addition, we propose a theoretical model to interpret the spreading process via both internal and external channels, considering three essential properties: (i) memory effect; (ii) role of spreaders; and (iii) non-redundancy of contacts. Experimental and mathematical results indicate that the information indeed spreads much quicker and broader with mutual effects of the internal and external influences. More importantly, the present model reveals that the event characteristic would highly determine the essential spreading patterns once the network structure is established. The results may shed some light on the in-depth understanding of the underlying dynamics of information transmission on real social networks.

  16. Adaptive integration of local region information to detect fine-scale brain activity patterns

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With the rapid development of functional magnetic resonance imaging (fMRI) technology, the spatial resolution of fMRI data is continuously growing. This pro- vides us the possibility to detect the fine-scale patterns of brain activities. The es- tablished univariate and multivariate methods to analyze fMRI data mostly focus on detecting the activation blobs without considering the distributed fine-scale pat- terns within the blobs. To improve the sensitivity of the activation detection, in this paper, multivariate statistical method and univariate statistical method are com- bined to discover the fine-grained activity patterns. For one voxel in the brain, a local homogenous region is constructed. Then, time courses from the local ho- mogenous region are integrated with multivariate statistical method. Univariate statistical method is finally used to construct the interests of statistic for that voxel. The approach has explicitly taken into account the structures of both activity pat- terns and existing noise of local brain regions. Therefore, it could highlight the fine-scale activity patterns of the local regions. Experiments with simulated and real fMRI data demonstrate that the proposed method dramatically increases the sensitivity of detection of fine-scale brain activity patterns which contain the subtle information about experimental conditions.

  17. Spontaneous assembly of chemically encoded two-dimensional coacervate droplet arrays by acoustic wave patterning

    Science.gov (United States)

    Tian, Liangfei; Martin, Nicolas; Bassindale, Philip G.; Patil, Avinash J.; Li, Mei; Barnes, Adrian; Drinkwater, Bruce W.; Mann, Stephen

    2016-10-01

    The spontaneous assembly of chemically encoded, molecularly crowded, water-rich micro-droplets into periodic defect-free two-dimensional arrays is achieved in aqueous media by a combination of an acoustic standing wave pressure field and in situ complex coacervation. Acoustically mediated coalescence of primary droplets generates single-droplet per node micro-arrays that exhibit variable surface-attachment properties, spontaneously uptake dyes, enzymes and particles, and display spatial and time-dependent fluorescence outputs when exposed to a reactant diffusion gradient. In addition, coacervate droplet arrays exhibiting dynamical behaviour and exchange of matter are prepared by inhibiting coalescence to produce acoustically trapped lattices of droplet clusters that display fast and reversible changes in shape and spatial configuration in direct response to modulations in the acoustic frequencies and fields. Our results offer a novel route to the design and construction of `water-in-water' micro-droplet arrays with controllable spatial organization, programmable signalling pathways and higher order collective behaviour.

  18. KP solitons and the Grassmannians combinatorics and geometry of two-dimensional wave patterns

    CERN Document Server

    Kodama, Yuji

    2017-01-01

    This is the first book to treat combinatorial and geometric aspects of two-dimensional solitons. Based on recent research by the author and his collaborators, the book presents new developments focused on an interplay between the theory of solitons and the combinatorics of finite-dimensional Grassmannians, in particular, the totally nonnegative (TNN) parts of the Grassmannians. The book begins with a brief introduction to the theory of the Kadomtsev–Petviashvili (KP) equation and its soliton solutions, called the KP solitons. Owing to the nonlinearity in the KP equation, the KP solitons form very complex but interesting web-like patterns in two dimensions. These patterns are referred to as soliton graphs. The main aim of the book is to investigate the detailed structure of the soliton graphs and to classify these graphs. It turns out that the problem has an intimate connection with the study of the TNN part of the Grassmannians. The book also provides an elementary introduction to the recent development of ...

  19. Gravitational wave luminosity and net momentum flux in head-on mergers of black holes: Radiative patterns and mode mixing

    Science.gov (United States)

    Aranha, Rafael Fernandes; Soares, Ivano Damião; Tonini, Eduardo Valentino

    2016-09-01

    We show that gravitational wave radiative patterns from a point test particle falling radially into a Schwarzschild black hole, as derived by Davis, Ruffini, Press and Price [M. Davis et al., Phys. Rev. Lett. 27, 1466 (1971).], are present in the nonlinear regime of head-on mergers of black holes. We use the Bondi-Sachs characteristic formulation and express the gravitational wave luminosity and the net momentum flux in terms of the news functions. We then evaluate the (-2 )-spin-weighted ℓ-multipole decomposition of these quantities via exact expressions valid in the nonlinear regime and defined at future null infinity. Our treatment is made in the realm of Robinson-Trautman dynamics, with characteristic initial data corresponding to the head-on merger of two black holes. We consider mass ratios in the range 0.01 ≤α ≤1 . We obtain the exponential decay with ℓ of the total energy contributed by each multipole ℓ, with an accurate linear correlation in the log-linear plot of the points up to α ≃0.7 . Above this mass ratio the contribution of the odd modes to the energy decreases faster than that of the even modes, leading to the breaking of the linear correlation; for α =1 the energy in all odd modes is zero. The dominant contribution to the total radiated energy comes from the quadrupole mode ℓ=2 corresponding, for instance, to about ≃84 % for small mass ratios up to ≃99.8 % for the limit case α =1 . The total rescaled radiated energy EWtotal/m0α2 decreases linearly with decreasing α , yielding for the point particle limit α →0 the value ≃0.0484 , about 5 times larger than the result of Davis et al. [1]. The mode decomposition of the net momentum flux and of the associated gravitational wave impulses results in an adjacent-even-odd mode-mixing pattern. We obtain that the impulses contributed by each (ℓ,ℓ+1 ) mixed mode also accurately satisfy the exponential decay with ℓ, for the whole mass ratio domain considered, 0.01 ≤α 0

  20. Spatial uncertainty modeling of fuzzy information in images for pattern classification.

    Directory of Open Access Journals (Sweden)

    Tuan D Pham

    Full Text Available The modeling of the spatial distribution of image properties is important for many pattern recognition problems in science and engineering. Mathematical methods are needed to quantify the variability of this spatial distribution based on which a decision of classification can be made in an optimal sense. However, image properties are often subject to uncertainty due to both incomplete and imprecise information. This paper presents an integrated approach for estimating the spatial uncertainty of vagueness in images using the theory of geostatistics and the calculus of probability measures of fuzzy events. Such a model for the quantification of spatial uncertainty is utilized as a new image feature extraction method, based on which classifiers can be trained to perform the task of pattern recognition. Applications of the proposed algorithm to the classification of various types of image data suggest the usefulness of the proposed uncertainty modeling technique for texture feature extraction.

  1. Assortativity coefficient-based estimation of population patterns of sexual mixing when cluster size is informative.

    Science.gov (United States)

    Young, Siobhan K; Lyles, Robert H; Kupper, Lawrence L; Keys, Jessica R; Martin, Sandra L; Costenbader, Elizabeth C

    2014-06-01

    Population sexual mixing patterns can be quantified using Newman's assortativity coefficient (r). Suggested methods for estimating the SE for r may lead to inappropriate statistical conclusions in situations where intracluster correlation is ignored and/or when cluster size is predictive of the response. We describe a computer-intensive, but highly accessible, within-cluster resampling approach for providing a valid large-sample estimated SE for r and an associated 95% CI. We introduce needed statistical notation and describe the within-cluster resampling approach. Sexual network data and a simulation study were employed to compare within-cluster resampling with standard methods when cluster size is informative. For the analysis of network data when cluster size is informative, the simulation study demonstrates that within-cluster resampling produces valid statistical inferences about Newman's assortativity coefficient, a popular statistic used to quantify the strength of mixing patterns. In contrast, commonly used methods are biased with attendant extremely poor CI coverage. Within-cluster resampling is recommended when cluster size is informative and/or when there is within-cluster response correlation. Within-cluster resampling is recommended for providing valid statistical inferences when applying Newman's assortativity coefficient r to network data. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  2. Linking Information Seeking Patterns with Purpose, Use, Value, and Return On Investment of Academic Library Journals

    Directory of Open Access Journals (Sweden)

    Donald W. King

    2013-06-01

    Full Text Available Objective – To demonstrate the power of the critical incident method in studying theinformation seeking patterns of university faculty.Methods – Faculty at five U.S. universities participated in a study concerning their information seeking and reading patterns involving scholarly journals. The surveys relied on a critical incident method of asking questions concerning the last journal article read. This method allows analysis of the relationships among the purposes of reading articles, ways in which faculty first learned about the articles, where they obtained them, aspects of their use, and the value or impact of the information read. Results – Results show that journal articles were by far the most used source of the last substantive piece of information used for work. Over half of article readings were from articles provided by libraries (52%, compared with 32.6% from personal subscriptions, and journal articles were the most frequent way faculty became aware of information prior to reading about it (33.9%, compared with 19.4% from informal discussions.Conclusion – This project has shown that articles read for the purpose of research, found by searching, and obtained from the library collections have the highest value to faculty by many measures. Library provided articles save faculty time and effort, which can be quantified using contingent valuation. The return on investment (ROI for library collections can be calculated by measuring all library costs and establishing the monetary returns to faculty members through contingent valuation. Library journal collections are estimated to have an ROI of between 3.3 and 3.6 to 1.

  3. Human longevity is associated with regular sleep patterns, maintenance of slow wave sleep, and favorable lipid profile

    Science.gov (United States)

    Mazzotti, Diego Robles; Guindalini, Camila; Moraes, Walter André dos Santos; Andersen, Monica Levy; Cendoroglo, Maysa Seabra; Ramos, Luiz Roberto; Tufik, Sergio

    2014-01-01

    Some individuals are able to successfully reach very old ages, reflecting higher adaptation against age-associated effects. Sleep is one of the processes deeply affected by aging; however few studies evaluating sleep in long-lived individuals (aged over 85) have been reported to date. The aim of this study was to characterize the sleep patterns and biochemical profile of oldest old individuals (N = 10, age 85–105 years old) and compare them to young adults (N = 15, age 20–30 years old) and older adults (N = 13, age 60–70 years old). All subjects underwent full-night polysomnography, 1-week of actigraphic recording and peripheral blood collection. Sleep electroencephalogram spectral analysis was also performed. The oldest old individuals showed lower sleep efficiency and REM sleep when compared to the older adults, while stage N3 percentage and delta power were similar across the groups. Oldest old individuals maintained strictly regular sleep-wake schedules and also presented higher HDL-cholesterol and lower triglyceride levels than older adults. The present study revealed novel data regarding specific sleep patterns and maintenance of slow wave sleep in the oldest old group. Taken together with the favorable lipid profile, these results contribute with evidence to the importance of sleep and lipid metabolism regulation in the maintenance of longevity in humans. PMID:25009494

  4. Changes in Urolithiasis Referral Patterns for Shock Wave Lithotripsy over a Decade: Was There Adherence to AUA/EAU Guidelines?

    Science.gov (United States)

    Noureldin, Yasser A; Elkoushy, Mohamed A; Andonian, Sero

    2015-09-01

    The primary objective was to assess changes in referral patterns of urolithiasis for shock wave lithotripsy (SWL) over a decade. The secondary objective was to evaluate the effect of the number of years of practice of referring physicians on these referral patterns. A retrospective review of SWL database was performed for consecutive referrals for SWL at a tertiary stone center between December 1999 and December 2013. Patient demographics and stone characteristics were assessed. The stone location at the time of referral was used as the reference. Retreatments were excluded. In addition, years of practice of the referring physicians were calculated. The 2007 AUA/EAU guidelines on urolithiasis were considered as a reference. A total of 8,992 SWL treatments were included. After December 2007, there was a significant increase in the percentage of renal pelvic stones referred for SWL (23.0 vs. 27.1%, p 10 mm (5.1 vs. 2.9%, p 0.05). Furthermore, percentage of stones referred for SWL by urologists practicing for less than 10 years significantly decreased after December 2007 (29.5 vs. 22.8%, p EAU guidelines on management of ureteral stones.

  5. Application of Geographic Information Systems (GIS) in Analysing Rainfall Distribution Patterns in Batu Pahat District

    Science.gov (United States)

    Kadir, A. A.; Kaamin, M.; Azizan, N. S.; Sahat, S.; Bukari, S. M.; Mokhtar, M.; Ngadiman, N.; Hamid, N. B.

    2016-07-01

    Rainfall forecasting reports are crucial to provide information and warnings to the population in a particular location. The Malaysian Meteorology Department (MMD) is a department that plays an important role in monitoring the situation and issued the statement of changes in weather and provides services such as weather advisories and gives warnings when the situation requires. Uncertain weather situations normally have created panic situation, especially in big cities because of flash floods due to poor drainage management. Usually, local authorities provided rainfall data in tables, and it is difficult to analyse to acquire the rainfall trend. Therefore, Geographic Information System (GIS) applications are commonly used to generate rainfall patterns in visual formation with a combination of characteristics of rainfall data and then can be used by stakeholders to facilitate the process of analysis and forecasting rainfall. The objective of this study is to determine the pattern of rainfall distribution using GIS applications in Batu Pahat district to assist interested parties to understand and easy to analyse the rainfall data in visual form or mapping form. Rainfall data for a period of 10 years (2004-2013) and monthly data (Dec 2006 - Feb 2007) are provided by the Department of Irrigation and Drainage (DID) for 12 stations in the district of Batu Pahat, and rainfall maps in each year was obtained using the interpolation Inverse Distance Weighted (IDW) method was used in this research. The rainfall map was then analyzed to identify the highest rainfall that was received during the period of study. For the conclusion, this study has proved that rainfall analysis using GIS application is efficient to be used in gaining information of rainfall patterns as the results show that the highest rainfall occurred in 2006 and 2007, and it were the years of major floods occurrence in Batu Pahat district.

  6. A New Skid Trail Pattern Design for Farm Tractors Using Linear Programing and Geographical Information Systems

    Directory of Open Access Journals (Sweden)

    Selcuk Gumus

    2016-12-01

    Full Text Available Farm tractor skidding is one of the common methods of timber extraction in Turkey. However, the absence of an optimal skidding plan covering the entire production area can result in time loss and negative environmental impacts. In this study, the timber extraction by farm tractors was analyzed, and a new skid trail pattern design was developed using Linear Programming (LP and Geographical Information Systems (GIS. First, a sample skidding operation was evaluated with a time study, and an optimum skidding model was generated with LP. Then, the new skidding pattern was developed by an optimum skidding model and GIS analysis. At the end of the study, the developed new skid trail pattern was implemented in the study area and tested by running a time study. Using the newly developed “Direct Skid Trail Pattern (DSTP” model, a 16.84% increase in working time performance was observed when the products were extracted by farm tractors compared to the existing practices. On the other hand, the average soil compaction value measured in the study area at depths of 0–5 cm and 5–10 cm was found to be greater in the sample area skid trails than in the control points. The average density of the skid trails was 281 m/ha, while it decreased to 187 m/ha by using the developed pattern. It was also found that 44,829 ton/ha of soil losses were prevented by using the DSTP model; therefore, environmental damages were decreased.

  7. Customized oligonucleotide microchips that convert multiple genetic information to simple patterns, are portable and reusable

    Science.gov (United States)

    Mirzabekov, Andrei; Guschin, Dmitry Y.; Chik, Valentine; Drobyshev, Aleksei; Fotin, Alexander; Yershov, Gennadiy; Lysov, Yuri

    2002-01-01

    This invention relates to using customized oligonucleotide microchips as biosensors for the detection and identification of nucleic acids specific for different genes, organisms and/or individuals in the environment, in food and in biological samples. The microchips are designed to convert multiple bits of genetic information into simpler patterns of signals that are interpreted as a unit. Because of an improved method of hybridizing oligonucleotides from samples to microchips, microchips are reusable and transportable. For field study, portable laser or bar code scanners are suitable.

  8. Multivoxel pattern analysis reveals 3D place information in the human hippocampus.

    Science.gov (United States)

    Kim, Misun; Jeffery, Kate J; Maguire, Eleanor A

    2017-03-20

    The spatial world is three-dimensional (3D), and humans and other animals move both horizontally and vertically within it. Extant neuroscientific studies have typically investigated spatial navigation on a horizontal two-dimensional plane, leaving much unknown about how 3D spatial information is represented in the brain. Specifically, horizontal and vertical information may be encoded in the same or different neural structures with equal or unequal sensitivity. Here, we investigated these possibilities using functional MRI (fMRI) while participants were passively moved within a 3D lattice structure as if riding a rollercoaster. Multivoxel pattern analysis was used to test for the existence of information relating to where and in which direction participants were heading in this virtual environment. Behaviorally, participants had similarly accurate memory for vertical and horizontal locations, and the right anterior hippocampus expressed place information that was sensitive to changes along both horizontal and vertical axes. This is suggestive of isotropic 3D place encoding. By contrast, participants indicated their heading direction faster and more accurately when they were heading in a tilted-up or tilted-down direction. This direction information was expressed in the right retrosplenial cortex and posterior hippocampus, and was only sensitive to vertical pitch, which could reflect the importance of the vertical (gravity) axis as a reference frame. Overall, our findings extend previous knowledge of how we represent the spatial world and navigate within it, by taking into account the important third dimension.SIGNIFICANCE STATEMENTThe spatial world is three-dimensional (3D) -- we can move horizontally across surfaces, but also vertically, going up slopes or stairs. Little is known about how the brain supports representations of 3D space. A key question is whether or not horizontal and vertical information is equally well represented. Here we measured functional MRI

  9. Risk and Ambiguity in Information Seeking: Eye Gaze Patterns Reveal Contextual Behavior in Dealing with Uncertainty.

    Science.gov (United States)

    Wittek, Peter; Liu, Ying-Hsang; Darányi, Sándor; Gedeon, Tom; Lim, Ik Soo

    2016-01-01

    Information foraging connects optimal foraging theory in ecology with how humans search for information. The theory suggests that, following an information scent, the information seeker must optimize the tradeoff between exploration by repeated steps in the search space vs. exploitation, using the resources encountered. We conjecture that this tradeoff characterizes how a user deals with uncertainty and its two aspects, risk and ambiguity in economic theory. Risk is related to the perceived quality of the actually visited patch of information, and can be reduced by exploiting and understanding the patch to a better extent. Ambiguity, on the other hand, is the opportunity cost of having higher quality patches elsewhere in the search space. The aforementioned tradeoff depends on many attributes, including traits of the user: at the two extreme ends of the spectrum, analytic and wholistic searchers employ entirely different strategies. The former type focuses on exploitation first, interspersed with bouts of exploration, whereas the latter type prefers to explore the search space first and consume later. Our findings from an eye-tracking study of experts' interactions with novel search interfaces in the biomedical domain suggest that user traits of cognitive styles and perceived search task difficulty are significantly correlated with eye gaze and search behavior. We also demonstrate that perceived risk shifts the balance between exploration and exploitation in either type of users, tilting it against vs. in favor of ambiguity minimization. Since the pattern of behavior in information foraging is quintessentially sequential, risk and ambiguity minimization cannot happen simultaneously, leading to a fundamental limit on how good such a tradeoff can be. This in turn connects information seeking with the emergent field of quantum decision theory.

  10. Risk and Ambiguity in Information Seeking: Eye Gaze Patterns Reveal Contextual Behaviour in Dealing with Uncertainty

    Directory of Open Access Journals (Sweden)

    Peter Wittek

    2016-11-01

    Full Text Available Information foraging connects optimal foraging theory in ecology withhow humans search for information. The theory suggests that, followingan information scent, the information seeker must optimize the tradeoffbetween exploration by repeated steps in the search space vs.exploitation, using the resources encountered. We conjecture that thistradeoff characterizes how a user deals with uncertainty and its twoaspects, risk and ambiguity in economic theory. Risk is related to theperceived quality of the actually visited patch of information, and canbe reduced by exploiting and understanding the patch to a better extent.Ambiguity, on the other hand, is the opportunity cost of having higherquality patches elsewhere in the search space. The aforementionedtradeoff depends on many attributes, including traits of the user: atthe two extreme ends of the spectrum, analytic and wholistic searchersemploy entirely different strategies. The former type focuses onexploitation first, interspersed with bouts of exploration, whereas thelatter type prefers to explore the search space first and consume later.Our findings from an eye-tracking study of experts' interactions withnovel search interfaces in the biomedical domain suggest that usertraits of cognitive styles and perceived search task difficultyare significantly correlated with eye gaze and search behaviour. Wealso demonstrate that perceived risk shifts the balance betweenexploration and exploitation in either type of users, tilting it againstvs. in favour of ambiguity minimization. Since the pattern of behaviourin information foraging is quintessentially sequential, risk andambiguity minimization cannot happen simultaneously, leading to afundamental limit on how good such a tradeoff can be. This in turnconnects information seeking with the emergent field of quantum decisiontheory.

  11. Efficient modelling of sand wave behaviour [Powerpoint Presentation

    NARCIS (Netherlands)

    Berg, van den Joris; Damme, van Ruud

    2004-01-01

    Sand waves form a pattern of more or less parallel ridges. The wave length is about 300 meters and the height up to 10 meters, which is a considerable amount of the total water depth. Sand waves migrate with speeds of about 10 meters per year. Information on their behaviour is valuable: the larger p

  12. Methods for measuring the impact of health information technologies on clinicians' patterns of work and communication.

    Science.gov (United States)

    Westbrook, Johanna I; Ampt, Amanda; Williamson, Margaret; Nguyen, Ken; Kearney, Leanne

    2007-01-01

    Evidence regarding how health information technologies influence clinical work patterns and support efficient practices is limited. Traditional paper-based data collection methods are unable to capture clinical work complexity and communication patterns. Our objective was to design and test an electronic data collection tool for work measurement studies which would allow efficient, accurate and reliable data collection, and capture work complexity. We developed software on a personal digital assistant (PDA) which captures details of nurses' work; what task, with whom, and with what; multi-tasking; interruptions and event duration. During field-testing over seven months across four hospital wards, fifty-two nurses were observed for 250 hours. Inter-rater reliability scores were maintained at over 85%. Only 1% of tasks did not match the classification developed. Over 40% of nurses' time was spent in direct care or professional communication, with 11.8% in multi-tasking. Nurses were interrupted approximately every 49 minutes. One quarter of interruptions occurred while nurses were preparing or administering medications. This approach produces data which provides greater insights into patterns of clinician's work than has previously been possible.

  13. Monthly Hydrological Model Evaluation through Mapping the Hydrological Pattern to Information Space

    Science.gov (United States)

    Pan, B.; Cong, Z.

    2014-12-01

    Conceptual and stochastic monthly hydrological models have been widely used for climatic change impact exploration and long-range stream flow forecast. With disparate philosophies and different but insufficient inputs, most of the existing models are capable of generating satisfying outputs, which reveals a relatively robust idiosyncrasy of hydrological pattern over monthly time scale. This research uses the epistemic-aleatory uncertainties evaluation framework to examine the information source sink terms and flows of 6 conceptual monthly water balance models and a seasonal autoregressive stochastic hydrologic model over 19 basins in Jiangxi Province, China and the experiment basins of MOPEX project. By using the stream technique of Lisp, we constructed two programming paradigms into which the hydrological models mentioned above could be fitted. We focus on detecting and explaining the best achievable predictive performances and data-revealed insufficient of the models in each paradigm, especially the hydrological meaning of the iteration variables in these models. Finally, we make an attempt to compare and connect these two paradigms against the backdrop of algorithmic information theory to help us form a better understanding of monthly hydrological pattern.

  14. Influence of standing-wave electric field pattern on the laser damage resistance of HfO sub 2 thin films

    CERN Document Server

    Protopapa, M L; De Tomasi, F; Di Giulio, M; Perrone, M R; Scaglione, S

    2002-01-01

    The standing-wave electric field pattern that forms inside an optical coating as a consequence of laser irradiation is one of the factors influencing the coating laser-induced damage threshold. The influence of the standing-wave electric field profile on the damage resistance to ultraviolet radiation of hafnium dioxide (HfO sub 2) thin films was investigated in this work. To this end, HfO sub 2 thin films of different thicknesses deposited by the electron beam evaporation technique at the same deposition conditions were analyzed. Laser damage thresholds of the samples were measured at 308 nm (XeCl laser) by the photoacoustic beam deflection technique and microscopic inspections. The dependence of the laser damage threshold on the standing-wave electric field pattern was analyzed.

  15. Sensory processing patterns predict the integration of information held in visual working memory.

    Science.gov (United States)

    Lowe, Matthew X; Stevenson, Ryan A; Wilson, Kristin E; Ouslis, Natasha E; Barense, Morgan D; Cant, Jonathan S; Ferber, Susanne

    2016-02-01

    Given the limited resources of visual working memory, multiple items may be remembered as an averaged group or ensemble. As a result, local information may be ill-defined, but these ensemble representations provide accurate diagnostics of the natural world by combining gist information with item-level information held in visual working memory. Some neurodevelopmental disorders are characterized by sensory processing profiles that predispose individuals to avoid or seek-out sensory stimulation, fundamentally altering their perceptual experience. Here, we report such processing styles will affect the computation of ensemble statistics in the general population. We identified stable adult sensory processing patterns to demonstrate that individuals with low sensory thresholds who show a greater proclivity to engage in active response strategies to prevent sensory overstimulation are less likely to integrate mean size information across a set of similar items and are therefore more likely to be biased away from the mean size representation of an ensemble display. We therefore propose the study of ensemble processing should extend beyond the statistics of the display, and should also consider the statistics of the observer. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. Sources of information and behavioral patterns in online health forums: observational study.

    Science.gov (United States)

    Sudau, Fabian; Friede, Tim; Grabowski, Jens; Koschack, Janka; Makedonski, Philip; Himmel, Wolfgang

    2014-01-14

    Increasing numbers of patients are raising their voice in online forums. This shift is welcome as an act of patient autonomy, reflected in the term "expert patient". At the same time, there is considerable concern that patients can be easily misguided by pseudoscientific research and debate. Little is known about the sources of information used in health-related online forums, how users apply this information, and how they behave in such forums. The intent of the study was to identify (1) the sources of information used in online health-related forums, and (2) the roles and behavior of active forum visitors in introducing and disseminating this information. This observational study used the largest German multiple sclerosis (MS) online forum as a database, analyzing the user debate about the recently proposed and controversial Chronic Cerebrospinal Venous Insufficiency (CCSVI) hypothesis. After extracting all posts and then filtering relevant CCSVI posts between 01 January 2008 and 17 August 2012, we first identified hyperlinks to scientific publications and other information sources used or referenced in the posts. Employing k-means clustering, we then analyzed the users' preference for sources of information and their general posting habits. Of 139,912 posts from 11,997 threads, 8628 posts discussed or at least mentioned CCSVI. We detected hyperlinks pointing to CCSVI-related scientific publications in 31 posts. In contrast, 2829 different URLs were posted to the forum, most frequently referring to social media, such as YouTube or Facebook. We identified a total of 6 different roles of hyperlink posters including Social Media Fans, Organization Followers, and Balanced Source Users. Apart from the large and nonspecific residual category of the "average user", several specific behavior patterns were identified, such as the small but relevant groups of CCSVI-Focused Responders or CCSVI Activators. The bulk of the observed contributions were not based on scientific

  17. Using Visualization of Seismic Waves in Teaching Earth Science Informed by Cognitive Science Research

    Science.gov (United States)

    Engelmann, C. A.; Waite, G. P.; Huntoon, J. E.; Hungwe, K.

    2011-12-01

    Seismologists have found visualization of scientific data to be useful in analysis and therefore expect that using visualizations as a pedagogical tool will increase student understanding of seismic waves. This project examines how seismic wave visualization activities should be designed to best take advantage of how students think and learn science as determined by research in cognitive science. Student activities using visualization and auditization of seismic waves as they propagate through the earth and activities using real-time seismometry, the Quake Catcher Network sensors, have been designed or modified for use in 7-12 Earth System Science classrooms, taking into account how students learn science. The activities will incorporate three visualizations introduced at the 2011 On the Cutting Edge workshop, Visualizing Seismic Waves for Teaching and Research: the USArray Visualizations developed by Dr. Charles Ammon, Penn State University; the Quake Catcher Network sensors in conjunction with IRIS's Exploring Seismic Data with Accelerometers; and The Sound of Seismic, John N. Louie's auditization of seismic waves. As part of the Michigan Teacher Excellence Program, a NSF funded Math Science Partnership between Michigan Tech University and Michigan public schools, these activities are being implemented and tested to determine in what ways and to what extent these visualizations impact student learning and understanding of seismic waves.

  18. The analysis of longitudinal quality of life measures with informative drop-out: a pattern mixture approach.

    Science.gov (United States)

    Post, Wendy J; Buijs, Ciska; Stolk, Ronald P; de Vries, Elisabeth G E; le Cessie, Saskia

    2010-02-01

    The analysis of longitudinal health-related quality of life measures (HRQOL) can be seriously hampered due to informative drop-out. Random effects models assume Missing At Random and do not take into account informative drop-out. We therefore aim to correct the bias due to informative drop-out. Analyses of data from a trial comparing standard-dose and high-dose chemotherapy for patients with breast cancer with respect to long-term impact on HRQOL will serve as illustration. The subscale Physical Function (PF) of the SF36 will be used. A pattern mixture approach is proposed to account for informative drop-out. Patterns are defined based on events related to HRQOL, such as death and relapse. The results of this pattern mixture approach are compared to the results of the commonly used random effects model. The findings of the pattern mixture approach are well interpretable, and different courses over time in different patterns are distinguished. In terms of estimated differences between standard dose and high dose, the results of both approaches are slightly different, but have no consequences for the clinical evaluation of both doses. Under the assumption that drop-out is at random within the patterns, the pattern mixture approach adjusts the estimates to a certain degree. This approach accounts in a relatively simple way for informative drop-out.

  19. Barotropic Interactions Between Summertime Tropical Cyclones/Sub-Monthly Wave Patterns and Intraseasonal Oscillations over the Western North Pacific

    Directory of Open Access Journals (Sweden)

    Ken-Chung Ko Huang-Hsiung Hsu

    2014-01-01

    Full Text Available This study used the barotropic kinetic energy conversion to record the active eddy-mean flow interaction between the TC/sub-monthly wave pattern (TSM and the intraseasonal oscillation (ISO in the western North Pacific (WNP. Overall, the TSM extracted (lost kinetic energy from (to the cyclonic (anticyclonic circulation of the ISO, which is located in the South China Sea and the Philippine Sea, during the ISO westerly (easterly phase. The phase change in barotropic energy conversion was due to the opposite background flow set up by the ISO. When the climatological-mean southwesterly was retained as part of the background flow in both ISO westerly and easterly phases as in previous studies, the ISO along with the low-frequency background flow always provided kinetic energy to the TSM regardless of the phase. The stronger (weaker southwesterly in the ISO westerly (easterly phase, the stronger (weaker energy conversion to the TSM. Climatological mean flow exclusion showed an upscale feedback in the TSM to the ISO during the easterly phase. However, this feedback was weaker than the downscale conversion from the ISO to the TSM during the westerly phase.

  20. Modeling contact angle hysteresis of a liquid droplet sitting on a cosine wave-like pattern surface.

    Science.gov (United States)

    Promraksa, Arwut; Chen, Li-Jen

    2012-10-15

    A liquid droplet sitting on a hydrophobic surface with a cosine wave-like square-array pattern in the Wenzel state is simulated by using the Surface Evolver to determine the contact angle. For a fixed drop volume, multiple metastable states are obtained at two different surface roughnesses. Unusual and non-circular shape of the three-phase contact line of a liquid droplet sitting on the model surface is observed due to corrugation and distortion of the contact line by structure of the roughness. The contact angle varies along the contact line for each metastable state. The maximum and minimum contact angles among the multiple metastable states at a fixed viewing angle correspond to the advancing and the receding contact angles, respectively. It is interesting to observe that the advancing/receding contact angles (and contact angle hysteresis) are a function of viewing angle. In addition, the receding (or advancing) contact angles at different viewing angles are determined at different metastable states. The contact angle of minimum energy among the multiple metastable states is defined as the most stable (equilibrium) contact angle. The Wenzel model is not able to describe the contact angle along the three-phase contact line. The contact angle hysteresis at different drop volumes is determined. The number of the metastable states increases with increasing drop volume. Drop volume effect on the contact angles is also discussed.

  1. Time-dependent wave selection for information processing in excitable media

    CERN Document Server

    Stevens, William M; Jahan, Ishrat; Costello, Ben de Lacy

    2012-01-01

    We demonstrate an improved technique for implementing logic circuits in light-sensitive chemical excitable media. The technique makes use of the constant-speed propagation of waves along defined channels in an excitable medium based on the Belousov-Zhabotinsky reaction, along with the mutual annihilation of colliding waves. What distinguishes this work from previous work in this area is that regions where channels meet at a junction can periodically alternate between permitting the propagation of waves and blocking them. These valve-like areas are used to select waves based on the length of time that it takes waves to propagate from one valve to another. In an experimental implementation, the channels which make up the circuit layout are projected by a digital projector connected to a computer. Excitable channels are projected as dark areas, unexcitable regions as light areas. Valves alternate between dark and light: every valve has the same period and phase, with a 50% duty cycle. This scheme can be used to ...

  2. Greenhouse gas implications of fleet electrification based on big data-informed individual travel patterns.

    Science.gov (United States)

    Cai, Hua; Xu, Ming

    2013-08-20

    Environmental implications of fleet electrification highly depend on the adoption and utilization of electric vehicles at the individual level. Past research has been constrained by using aggregated data to assume all vehicles with the same travel pattern as the aggregated average. This neglects the inherent heterogeneity of individual travel behaviors and may lead to unrealistic estimation of environmental impacts of fleet electrification. Using "big data" mining techniques, this research examines real-time vehicle trajectory data for 10,375 taxis in Beijing in one week to characterize the travel patterns of individual taxis. We then evaluate the impact of adopting plug-in hybrid electric vehicles (PHEV) in the taxi fleet on life cycle greenhouse gas emissions based on the characterized individual travel patterns. The results indicate that 1) the largest gasoline displacement (1.1 million gallons per year) can be achieved by adopting PHEVs with modest electric range (approximately 80 miles) with current battery cost, limited public charging infrastructure, and no government subsidy; 2) reducing battery cost has the largest impact on increasing the electrification rate of vehicle mileage traveled (VMT), thus increasing gasoline displacement, followed by diversified charging opportunities; 3) government subsidies can be more effective to increase the VMT electrification rate and gasoline displacement if targeted to PHEVs with modest electric ranges (80 to 120 miles); and 4) while taxi fleet electrification can increase greenhouse gas emissions by up to 115 kiloton CO2-eq per year with the current grid in Beijing, emission reduction of up to 36.5 kiloton CO2-eq per year can be achieved if the fuel cycle emission factor of electricity can be reduced to 168.7 g/km. Although the results are based on a specific public fleet, this study demonstrates the benefit of using large-scale individual-based trajectory data (big data) to better understand environmental implications

  3. Endogenous bioelectrical networks store non-genetic patterning information during development and regeneration.

    Science.gov (United States)

    Levin, Michael

    2014-06-01

    Pattern formation, as occurs during embryogenesis or regeneration, is the crucial link between genotype and the functions upon which selection operates. Even cancer and aging can be seen as challenges to the continuous physiological processes that orchestrate individual cell activities toward the anatomical needs of an organism. Thus, the origin and maintenance of complex biological shape is a fundamental question for cell, developmental, and evolutionary biology, as well as for biomedicine. It has long been recognized that slow bioelectrical gradients can control cell behaviors and morphogenesis. Here, I review recent molecular data that implicate endogenous spatio-temporal patterns of resting potentials among non-excitable cells as instructive cues in embryogenesis, regeneration, and cancer. Functional data have implicated gradients of resting potential in processes such as limb regeneration, eye induction, craniofacial patterning, and head-tail polarity, as well as in metastatic transformation and tumorigenesis. The genome is tightly linked to bioelectric signaling, via ion channel proteins that shape the gradients, downstream genes whose transcription is regulated by voltage, and transduction machinery that converts changes in bioelectric state to second-messenger cascades. However, the data clearly indicate that bioelectric signaling is an autonomous layer of control not reducible to a biochemical or genetic account of cell state. The real-time dynamics of bioelectric communication among cells are not fully captured by transcriptomic or proteomic analyses, and the necessary-and-sufficient triggers for specific changes in growth and form can be physiological states, while the underlying gene loci are free to diverge. The next steps in this exciting new field include the development of novel conceptual tools for understanding the anatomical semantics encoded in non-neural bioelectrical networks, and of improved biophysical tools for reading and writing

  4. Keywords and Co-Occurrence Patterns in the Voynich Manuscript: An Information-Theoretic Analysis.

    Science.gov (United States)

    Montemurro, Marcelo A; Zanette, Damián H

    2013-01-01

    The Voynich manuscript has remained so far as a mystery for linguists and cryptologists. While the text written on medieval parchment -using an unknown script system- shows basic statistical patterns that bear resemblance to those from real languages, there are features that suggested to some researches that the manuscript was a forgery intended as a hoax. Here we analyse the long-range structure of the manuscript using methods from information theory. We show that the Voynich manuscript presents a complex organization in the distribution of words that is compatible with those found in real language sequences. We are also able to extract some of the most significant semantic word-networks in the text. These results together with some previously known statistical features of the Voynich manuscript, give support to the presence of a genuine message inside the book.

  5. Investigating the Effects of Information and Communication Technology (ICT on Citizens’ Travel Pattern

    Directory of Open Access Journals (Sweden)

    Ali Soltani

    2013-03-01

    Full Text Available This study makes an effort to investigate the effects of Information and Communication Technology (ICT on daily urban travel patterns. The main research question is based on the capability of ICT in reducing trip production (generation and attraction. The results obtained from the analysis of the data extracted from a questionnaire given to a sample population of 300 people from Golestan Town, Shiraz-South of Iran - in 2011 revealed that there is a tendency towards decreasing the amount of urban travels through encouraging virtual travels and telecommuting. Most of the people who answered the questionnaire tend to have an economical approach towards the daily travel patterns through the use of at least one ICT method for special trips. On the other hand, the majority of the people questioned believed that ICT has not been full successful in replacing physical trips to supply various needs and can only be of use as a powerful supplement for the purpose of decreasing the amount of physical trips if the existing services are improved and enjoy a higher level of public satisfaction.

  6. Congruent patterns of connectivity can inform management for broadcast spawning corals on the Great Barrier Reef.

    Science.gov (United States)

    Lukoschek, Vimoksalehi; Riginos, Cynthia; van Oppen, Madeleine J H

    2016-07-01

    Connectivity underpins the persistence and recovery of marine ecosystems. The Great Barrier Reef (GBR) is the world's largest coral reef ecosystem and managed by an extensive network of no-take zones; however, information about connectivity was not available to optimize the network's configuration. We use multivariate analyses, Bayesian clustering algorithms and assignment tests of the largest population genetic data set for any organism on the GBR to date (Acropora tenuis, >2500 colonies; >50 reefs, genotyped for ten microsatellite loci) to demonstrate highly congruent patterns of connectivity between this common broadcast spawning reef-building coral and its congener Acropora millepora (~950 colonies; 20 reefs, genotyped for 12 microsatellite loci). For both species, there is a genetic divide at around 19°S latitude, most probably reflecting allopatric differentiation during the Pleistocene. GBR reefs north of 19°S are essentially panmictic whereas southern reefs are genetically distinct with higher levels of genetic diversity and population structure, most notably genetic subdivision between inshore and offshore reefs south of 19°S. These broadly congruent patterns of higher genetic diversities found on southern GBR reefs most likely represent the accumulation of alleles via the southward flowing East Australia Current. In addition, signatures of genetic admixture between the Coral Sea and outer-shelf reefs in the northern, central and southern GBR provide evidence of recent gene flow. Our connectivity results are consistent with predictions from recently published larval dispersal models for broadcast spawning corals on the GBR, thereby providing robust connectivity information about the dominant reef-building genus Acropora for coral reef managers.

  7. Spatio-temporal pattern of vestibular information processing after brief caloric stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Marcelli, Vincenzo [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Esposito, Fabrizio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands)], E-mail: fabrizio.esposito@unina.it; Aragri, Adriana [Department of Neurological Sciences, Second University of Naples, Naples (Italy); Furia, Teresa; Riccardi, Pasquale [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Tosetti, Michela; Biagi, Laura [I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Marciano, Elio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Di Salle, Francesco [Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands); I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Department of Neurosciences, University of Pisa, Pisa (Italy)

    2009-05-15

    Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.

  8. ‘Merantau’ - an Informal Entrepreneurial Learning Pattern in the Culture of Minangkabau Tribe in Indonesia

    Directory of Open Access Journals (Sweden)

    Hafiz Rahman

    2016-06-01

    Full Text Available The aim of this paper is to expose an informal entrepreneurial learning pattern that is undertaken by the Minangkabau tribe in Indonesia and relate it to cultural dimension and perceived value of a society. This informal entrepreneurial learning pattern is called as ‘Merantau’ - which can simply be meant as ‘to emigrate’, in which the young males (mostly during the ages of 15-20, or even younger leave their homeland; move to other places nationwide or abroad, and running entrepreneurial activities for their daily life. The existence of merantau as an informal cultural based entrepreneurial learning for the young Minangkabau tribe combined with their cultural dimension and perceived values have contributed to the creation of and bring positive impacts to entrepreneurial culture of the Minangkabau tribe. The Minangkabau tribe, as one of tribes in Indonesia, experiences very supportive social environment in which entrepreneurial culture is recognised as part of the way of life. Therefore, Minangkabau tribe is known as one of the most entrepreneurial tribes in Indonesia. This paper considers perceived value and cultural dimension that may bring consequence to entrepreneurial culture of a society, with particular analysis to Minangkabau tribe in Indonesia. Analysis is undertaken by considering the elements and index of cultural dimension and perceived values of a society that can create and intiate entreprenuerial habits and relate them to entrepreneurship. Result of the analysis shows an evidence that culture of a society also plays an important role to create and maintain entrepreneurial habits and experience of a society. Together with cultural dimension of a society, perceived values that a society has, also contributes to the creation of entrepreneurial culture of that society. This is shown in the context of the Minangkabau tribe who is well known as an entrepreneurial tribe in Indonesia. However, this study analyses one single cultural

  9. Review on Available Information on Waves in the DanWEC Area

    DEFF Research Database (Denmark)

    Margheritini, Lucia

    at creating a local base for knowledge, education and possibly a workplace which will be leased out to trial projects. It is therefore likely that different developers will deploy their wave energy devices during the next years in this location and therefore detailed knowledge on a number of environmental...

  10. Analysis of phylogenetic signal in protostomial intron patterns using Mutual Information.

    Science.gov (United States)

    Hill, Natascha; Leow, Alexander; Bleidorn, Christoph; Groth, Detlef; Tiedemann, Ralph; Selbig, Joachim; Hartmann, Stefanie

    2013-06-01

    Many deep evolutionary divergences still remain unresolved, such as those among major taxa of the Lophotrochozoa. As alternative phylogenetic markers, the intron-exon structure of eukaryotic genomes and the patterns of absence and presence of spliceosomal introns appear to be promising. However, given the potential homoplasy of intron presence, the phylogenetic analysis of this data using standard evolutionary approaches has remained a challenge. Here, we used Mutual Information (MI) to estimate the phylogeny of Protostomia using gene structure data, and we compared these results with those obtained with Dollo Parsimony. Using full genome sequences from nine Metazoa, we identified 447 groups of orthologous sequences with 21,732 introns in 4,870 unique intron positions. We determined the shared absence and presence of introns in the corresponding sequence alignments and have made this data available in "IntronBase", a web-accessible and downloadable SQLite database. Our results obtained using Dollo Parsimony are obviously misled through systematic errors that arise from multiple intron loss events, but extensive filtering of data improved the quality of the estimated phylogenies. Mutual Information, in contrast, performs better with larger datasets, but at the same time it requires a complete data set, which is difficult to obtain for orthologs from a large number of taxa. Nevertheless, Mutual Information-based distances proved to be useful in analyzing this kind of data, also because the estimation of MI-based distances is independent of evolutionary models and therefore no pre-definitions of ancestral and derived character states are necessary.

  11. Information

    CERN Document Server

    Ritchie, L David

    1991-01-01

    This volume thoroughly covers the sub-field of information, and is one of the first in a series which synthesizes the research literature on major concepts in the field of communication. Each concise volume includes a research definition (concept explication) and presents a state-of-the-art analysis of theory and empirical findings related to the concept. After defining the word `information', the author contrasts non-linear and reflexive ideas about human communication with linear perspectives. Information is equated with uncertainty. The result presents a pattern for the process of conceptua

  12. Use and Abuse of the Fisher Information Matrix in the Assessment of Gravitational-Wave Parameter-Estimation Prospects

    CERN Document Server

    Vallisneri, M

    2007-01-01

    The Fisher-matrix formalism is used routinely in the literature on gravitational-wave detection to characterize the parameter-estimation performance of gravitational-wave measurements, given parametrized models of the waveforms, and assuming detector noise of known colored Gaussian distribution. Unfortunately, the Fisher matrix can be a poor predictor of the amount of information obtained from typical observations, especially for waveforms with several parameters and relatively low expected signal-to-noise ratios (SNR), or for waveforms depending weakly on one or more parameters, when their priors are not taken into proper consideration. In this paper I discuss these pitfalls; show how they occur, even for relatively strong signals, with a commonly used template family for binary-inspiral waveforms; and describe practical recipes to recognize them and cope with them. Specifically, I answer the following questions: (i) What is the significance of (quasi-)singular Fisher matrices, and how must we deal with them...

  13. Layering ratios: a systematic approach to the inversion of surface wave data in the absence of a priori information

    Science.gov (United States)

    Cox, Brady R.; Teague, David P.

    2016-10-01

    Surface wave methods provide a cost effective means of developing shear wave velocity (Vs) profiles for applications such as dynamic site characterization and seismic site response analyses. However, the inverse problem involved in obtaining a realistic layered earth model from surface wave dispersion data is inherently ill-posed, non-linear and mix-determined, without a unique solution. When available, a priori information such as geotechnical boreholes or geologic well logs should be used to aid in constraining site-specific inversion parameters. Unfortunately, a priori information is often unavailable, particularly at significant depths, and a `blind analysis' must be performed. In these situations, the analyst must decide on an appropriate number of layers and ranges for their corresponding inversion parameters (i.e. trial number of layers and ranges in their respective thicknesses, shear wave velocities, compression wave velocities and mass densities). Selection of these parameters has been shown to significantly impact the results of an inversion. This paper presents a method for conducting multiple inversions utilizing systematically varied inversion layering parametrizations in order to identify and encompass the most reasonable layered earth models for a site. Each parametrization is defined by a unique layering ratio, which represents a multiplier that systemically increases the potential thickness of each layer in the inversion parametrization based on the potential thickness of the layer directly above it. The layering ratio method is demonstrated at two sites associated with the InterPacific Project, wherein it is shown to significantly aid in selecting reasonable Vs profiles that are close representations of the subsurface. While the goal of the layering ratio inversion methodology is not necessarily to find the `optimal' or `best' Vs profile for a site, it may be successful at doing so for certain sites/datasets. However, the primary reason for using

  14. Technical Perspective on Using Information Demand Pattern in a Collaborative Recommendation System for Improving E-Mail Communication

    Directory of Open Access Journals (Sweden)

    Dirk Stamer

    2015-04-01

    Full Text Available Today e-mail communication information is widely used in organizations to distribute information. The increasing volume of received e-mails hinders an efficient work. It becomes more and more difficult to identify relevant e-mails inside this enormous volume of information. This work presents a solution in a multi-user environment by improving an established e-mail client extension based on information demand pattern with a recommendation system. The contributions of this work are (1 the concept and implementation of the solution for a single-user environment using information demand pattern, (2 the concept and architecture to use the solution in a multi-user environment (3 a detailed technical description about the proposed solutions.

  15. Sequential pattern mining for discovering gene interactions and their contextual information from biomedical texts.

    Science.gov (United States)

    Cellier, Peggy; Charnois, Thierry; Plantevit, Marc; Rigotti, Christophe; Crémilleux, Bruno; Gandrillon, Olivier; Kléma, Jiří; Manguin, Jean-Luc

    2015-01-01

    Discovering gene interactions and their characterizations from biological text collections is a crucial issue in bioinformatics. Indeed, text collections are large and it is very difficult for biologists to fully take benefit from this amount of knowledge. Natural Language Processing (NLP) methods have been applied to extract background knowledge from biomedical texts. Some of existing NLP approaches are based on handcrafted rules and thus are time consuming and often devoted to a specific corpus. Machine learning based NLP methods, give good results but generate outcomes that are not really understandable by a user. We take advantage of an hybridization of data mining and natural language processing to propose an original symbolic method to automatically produce patterns conveying gene interactions and their characterizations. Therefore, our method not only allows gene interactions but also semantics information on the extracted interactions (e.g., modalities, biological contexts, interaction types) to be detected. Only limited resource is required: the text collection that is used as a training corpus. Our approach gives results comparable to the results given by state-of-the-art methods and is even better for the gene interaction detection in AIMed. Experiments show how our approach enables to discover interactions and their characterizations. To the best of our knowledge, there is few methods that automatically extract the interactions and also associated semantics information. The extracted gene interactions from PubMed are available through a simple web interface at https://bingotexte.greyc.fr/. The software is available at https://bingo2.greyc.fr/?q=node/22.

  16. Patterns of chromatic information processing in the lobula of the honeybee, Apis mellifera L.

    Science.gov (United States)

    Yang, En-Cheng; Lin, Hsiao-Chun; Hung, Yu-Shan

    2004-10-01

    The honeybee, Apis mellifera L., is one of the living creatures that has its colour vision proven through behavioural tests. Previous studies of honeybee colour vision has emphasized the relationship between the spectral sensitivities of photoreceptors and colour discrimination behaviour. The current understanding of the neural mechanisms of bee colour vision is, however, rather limited. The present study surveyed the patterns of chromatic information processing of visual neurons in the lobula of the honeybee, using intracellular recording stimulated by three light-emitting diodes, whose emission spectra approximately match the spectral sensitivity peaks of the honeybee. The recorded visual neurons can be divided into two groups: non-colour opponent cells and colour opponent cells. The non-colour opponent cells comprise six types of broad-band neurons and four response types of narrow-band neurons. The former might detect brightness of the environment or function as chromatic input channels, and the latter might supply specific chromatic input. Amongst the colour opponent cells, the principal neural mechanism of colour vision, eight response types were recorded. The receptive fields of these neurons were not centre surround as observed in primates. Some recorded neurons with tonic post-stimulus responses were observed, however, suggesting temporal defined spectral opponency may be part of the colour-coding mechanisms.

  17. GeoInformation studies of soil and vegetation patterns along Climatic Gradients: A Review

    Science.gov (United States)

    Shoshany, M.

    2009-04-01

    Global evidence regarding magnitudes of desertification processes and recognition in their societal, ecological and climatological consequences had lead the international community to establish the United Nations Convention to Combat Desertification (UNCCD). Within the framework of this convention it is perceived that Desertification is a complex poorly understood phenomena which is " first and foremost, the result of resource management failures". Scientific research within this context have three primary roles: monitoring the situation, developing the understanding of relationships between factors promoting desertification and finally providing the international community with efficient recommendations regarding actions which may slow down these processes. Study of desertification processes in regions of sharp climatic gradients is of special importance within this framework since they represent areas where the processes are most intensive and where most deserts actually expand. The detection of threshold zones coupling sever land degradation with loss of resilience in their eco-geomophic systems is fundamental for the efficient combating of global desertification. Application of geoinformation tools and techniques is instrumental for this purpose: mapping biological, chemical and physical surface properties using remote sensing techniques, mapping historical patch-pattern changes using air-photographs, analysis of spatio-temporal variations in pattern properties and analysis of informational relationships between these surface properties and patterns with climatoloical, topographic, lithological and human factors. Numerous Remote Sensing studies had been undertaken during the last four decades in monitoring desertification through the provision of maps describing spatial distributions of biophysical surface parameters at resolutions between few meters to few kilometers and temporal resolutions between hours and weeks. These studies utilized radar backscattering

  18. The Challenges of Democratizing News and Information: Examining Data on Social Media, Viral Patterns and Digital Influence

    OpenAIRE

    Wihbey, John P

    2014-01-01

    The advent of social media and peer-to-peer technologies offers the possibility of driving the full democratization of news and information, undercutting the agenda-setting of large media outlets and their relative control of news and information flows. We are now about a decade into the era of the social Web. What do the data indicate about changing news flows and access/consumption patterns in the United States? Are we witnessing a paradigm shift yet, or are legacy patterns reasserting them...

  19. A Geographic Information Science (GISc) Approach to Characterizing Spatiotemporal Patterns of Terrorist Incidents in Iraq, 2004-2009

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Richard M [ORNL; Siebeneck, Laura K. [University of Utah; Hepner, George F. [University of Utah

    2011-01-01

    As terrorism on all scales continues, it is necessary to improve understanding of terrorist and insurgent activities. This article takes a Geographic Information Systems (GIS) approach to advance the understanding of spatial, social, political, and cultural triggers that influence terrorism incidents. Spatial, temporal, and spatiotemporal patterns of terrorist attacks are examined to improve knowledge about terrorist systems of training, planning, and actions. The results of this study aim to provide a foundation for understanding attack patterns and tactics in emerging havens as well as inform the creation and implementation of various counterterrorism measures.

  20. Signal information available for plume source tracking with and without surface waves and learning by undergraduates assisting with the research

    Science.gov (United States)

    Wiley, Megan Beth

    Autonomous vehicles have had limited success in locating point sources of pollutants, chemicals, and other passive scalars. However, animals such as stomatopods, a mantis shrimp, track odor plumes easily for food, mates, and habitat. Laboratory experiments using Planar Laser Induced Fluorescence measured odor concentration downstream of a diffusive source with and without live stomatopods to investigate their source-tracking strategies in unidirectional and "wave-affected" (surface waves with a mean current) flows. Despite the dearth of signal, extreme temporal variation, and meandering plume centerline, the stomatopods were able to locate the source, especially in the wave-affected flow. Differences in the two plumes far from the source (>160 cm) appeared to help the animals in the wave-affected flow position themselves closer to the source (<70 cm) at times with relatively large amounts of odor and plume filaments of high concentration. At the height of the animals' antennules, the site of their primary chemosensors, the time-averaged Reynolds stresses in the two flows were approximately the same. The temporal variation in stresses over the wave cycle may be responsible for differences in the two plumes. The antennule height falls between a region of large peaks in Reynolds stress in phase with peaks in streamwise acceleration, and a lower region with a smaller Reynolds stress peak in phase with maximum shear during flow reversal. Six undergraduate students assisted with the research. We documented their daily activities and ideas on plume dispersion using open-ended interviews. Most of their time was spent on tasks that required no understanding of fluid mechanics, and there was little evidence of learning by participation in the RAship. One RA's conceptions of turbulence did change, but a group workshop seemed to support this learning more than the RAship. The documented conceptions could aid in curriculum design, since situating new information within current

  1. Patterns of megaclasts along the coast of Eastern Samar (Philippines) - Implications for Holocene extreme-wave events

    Science.gov (United States)

    Engel, Max; Boesl, Fabian; Narod Eco, Rodrigo; Galang, Jam Albert; Gonzalo, Lia Anne; Llanes, Francesca; Quix, Eva; Schroeder-Ritzrau, Andrea; Frank, Norbert; Mahar Lagmay, Alfredo; Brückner, Helmut

    2017-04-01

    The Eastern Visayas region in the Philippines is hit by some of the most violent tropical cyclones on Earth on a regular basis, exemplified by Typhoon Haiyan, 7-9 November 2013, and a number of other category 4 and 5 events during the last decades. Moreover, strong earthquakes along the Philippine Trench have triggered several tsunamis in the historical past. Coastal flooding through extreme waves associated with these events represents a significant hazard for communities along the eastern coasts of Samar. However, not much is known about frequency-magnitude relationships of coastal flooding events and the maximum magnitude on centennial and millennial scales, which can be derived from geological traces and which have to be considered in a coastal hazard management process. We investigated a large boulder field in Eastern Samar distributed over an elevated, intertidal palaeo-reef platform in order to understand mechanisms of boulder transport and to derive implications for the maximum spatial extent, height, and velocity of coastal flooding. In the field, we recorded location, shape, morphological features as well as length and orientation of the main axes of more than 250 boulders, the a-axes of which were between 1.5 and 10.7 m. Eight samples were taken for Th/U dating of post-depositional, secondary calcite flowstones and pre-depostional coral, and four samples were taken for radiocarbon dating of pre-depositional, sessil organisms attached to the boulders. We 3D-mapped the most important parts of the boulder field using an unmanned aerial vehicle (UAV) and created structure-from-motion (SfM) models of the most prominent boulders, which will be used for inverse modelling of transport flows. Samples of the most common coralline lithofacies were taken for density estimations. We used interviews with elders of the local community as well as multi-temporal analysis of satellite images to reconstruct recent flooding patterns and boulder movement during recent events

  2. Assessing spatial patterns of HIV knowledge in rural Mozambique using geographic information systems.

    Science.gov (United States)

    Buehler, Charlotte P; Blevins, Meridith; Ossemane, Ezequiel B; González-Calvo, Lázaro; Ndatimana, Elisée; Vermund, Sten H; Sidat, Mohsin; Olupona, Omo; Moon, Troy D

    2015-03-01

    To conduct a cross-sectional mapping analysis of HIV knowledge in Zambézia Province, Mozambique, and to examine spatial patterns of HIV knowledge and associated household characteristics. A population-based cluster survey was administered in 2010; data were analysed from 201 enumeration areas in three geographically diverse districts: Alto Molócuè, Morrumbala and Namacurra. We assessed HIV knowledge scores (0-9 points) using previously validated assessment tools. Using geographic information systems (GIS), we mapped hot spots of high and low HIV knowledge. Our multivariable linear regression model estimated HIV knowledge associations with distance to nearest clinic offering antiretroviral therapy, respondent age, education, household size, number of children under five, numeracy, literacy and district of residence. We found little overall HIV knowledge in all three districts. People in Alto Molócuè knew comparatively most about HIV, with a median score of 3 (IQR 2-5) and 22 of 51 (43%) enumeration areas scoring ≥4 of 9 points. Namacurra district, closest to the capital city and expected to have the best HIV knowledge levels, had a median score of 1 (IQR 0-3) and only 3 of 57 (5%) enumeration areas scoring ≥4 points. More HIV knowledge was associated with more education, age, household size, numeracy and proximity to a health facility offering antiretroviral therapy. HIV knowledge is critical for its prevention and treatment. By pinpointing areas of poor HIV knowledge, programme planners can prioritize educational resources and outreach initiatives within the context of antiretroviral therapy expansion. © 2014 John Wiley & Sons Ltd.

  3. Using High Performance Computing to Examine the Processes of Neurogenesis Underlying Pattern Separation/Completion of Episodic Information.

    Energy Technology Data Exchange (ETDEWEB)

    Aimone, James Bradley [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Betty, Rita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Using High Performance Computing to Examine the Processes of Neurogenesis Underlying Pattern Separation/Completion of Episodic Information - Sandia researchers developed novel methods and metrics for studying the computational function of neurogenesis, thus generating substantial impact to the neuroscience and neural computing communities. This work could benefit applications in machine learning and other analysis activities.

  4. Requirement Pattern Based on Dependencies of Plan in i* for Detecting Proactivity in Information-Technology Systems

    Directory of Open Access Journals (Sweden)

    Alain Pérez Acosta

    2016-04-01

    Full Text Available This paper aims to present a requirement pattern based on i*’s models that allows detecting proactivityin information-technology systems from the Requirements’ phase. The pattern obtained as a result ofthis paper allows detecting proactivity when there is a plan’s dependence established between the actorsinvolved and in addition one of the actors has intentions that denote a future proactive behavior inthe software. In order to validate the pattern a case study was performed taking as logic of analysis thedevelopment of a proactive dashboard to support the decision making in a college faculty. Based on theresults of the case study, it can be concluded that the proposed pattern allowed modeling the intentionaldependencies between the actors, detecting a proactive behavior and delegating the proactivity in thesystem of software to be developed.

  5. An Exploration of Search Patterns and Credibility Issues among Older Adults Seeking Online Health Information

    Science.gov (United States)

    Robertson-Lang, Laura; Major, Sonya; Hemming, Heather

    2011-01-01

    The Internet is an important resource for health information, among younger and older people alike. Unfortunately, there are limitations associated with online health information. Research is needed on the quality of information found online and on whether users are being critical consumers of the information they find. Also, there is a need for…

  6. Does Preference for Abstract Patterns Relate to Information Processing and Perceived Duration?

    Directory of Open Access Journals (Sweden)

    Letizia Palumbo

    2015-09-01

    Full Text Available Repetitive prestimulation, in the form of click trains, is known to alter a wide range of cognitive and perceptual judgments. To date, no research has explored whether click trains also influence subjective preferences. This is plausible because preference is related to perceptual fluency and clicks may increase fluency, or, because preference is related to arousal and clicks may increase arousal. In Experiment 1, participants heard a click train, white noise, or silence through headphones and then saw an abstract symmetrical pattern on the screen for 0.5, 1, or 1.5 s. They rated the pattern on a 7-point scale. Click trains had no effect on preference ratings, although patterns that lasted longer were preferred. In Experiment 2, we again presented a click train, silence, or white noise but included both symmetrical and random patterns. Participants made both a duration and a preference judgment on every trial. Auditory click trains increased perceived duration, and symmetrical patterns were perceived as lasting longer than random patterns. Again there was no effect of auditory click trains on preference, and again patterns that were presented for longer were preferred. We conclude that click trains alter perceptual and cognitive processes, but not preferences. This helps clarify the nature of the click train effect and shows which predictions implicit in the existing literature are supported.

  7. Design science research methods and patterns innovating information and communication technology

    CERN Document Server

    Vaishnavi, Vijay K

    2015-01-01

    Presenting innovative research methods, this second edition of a bestseller describes a simple and practical methodology for conducting cutting-edge design science research (DSR). It provides comprehensive guidance on how to conduct such research and supplies in-depth treatment of design science theory and the different types of theory that can be generated in design science research.Making novel use of the concept of patterns, it presents 84 research patterns for conducting effective DSR. It emphasizes design science theory throughout and is filled with practical examples of using patterns to

  8. Asymmetric coupling and dispersion of surface-plasmon-polariton waves on a periodically patterned anisotropic metal film

    CERN Document Server

    Dutta, Jhuma; Lakhtakia, Akhlesh

    2014-01-01

    The morphology of a columnar thin film (CTF) of silver renders it an effectively biaxially anisotropic continuum. CTFs of silver deposited on one-dimensional gratings of photoresist showed strong blazing action and asymmetrically coupled optical radiation to surface plasmon-polariton (SPP) waves propagating only along one direction supported by either the CTF/photoresist or the CTF/air interfaces. Homogenization of the CTFs using the Bruggeman formalism revealed them to display hyperbolic dispersion, and the dispersion of SPP waves was adequately described thereby.

  9. Asymmetric coupling and dispersion of surface-plasmon-polariton waves on a periodically patterned anisotropic metal film

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Jhuma; Ramakrishna, S. Anantha [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Lakhtakia, Akhlesh, E-mail: akhlesh@psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2015-01-07

    The morphology of a columnar thin film (CTF) of silver renders it an effectively biaxially anisotropic continuum. CTFs of silver deposited on one-dimensional gratings of photoresist showed strong blazing action and asymmetrically coupled optical radiation to surface-plasmon-polariton (SPP) waves propagating only along one direction supported by either the CTF/photoresist or the CTF/air interfaces. Homogenization of the CTFs using the Bruggeman formalism revealed them to display hyperbolic dispersion, and the dispersion of SPP waves was adequately described thereby.

  10. [The relationship between the infant nursing bottle caries and the feeding patterns, oral health behavior and parents' oral health information].

    Science.gov (United States)

    Zhong, Zhao-qi

    2009-12-01

    To investigate the relationship between the infant nursing bottle caries in city community and the feeding patterns, oral health behavior, parents' oral health information, and to provide scientific basis for future infant nursing bottle caries prevention. Three hundred infants aged 6, 7, 12, 18 months in April 2009 in Bai Guan Street Community Hospital Shangyu City were enrolled in this study, nursing bottle caries were examined and recorded. Questionnaires on infant basic data, feeding patterns, oral health behavior, parents' oral health information were asked and recorded in these 300 parents. The relationship was analyzed between the infant nursing bottle caries and the questionnaires by Chi-square test with the SPSS14.0 software package. The infant nursing bottle caries correlated obviously with the habit of sleeping with the nursing bottle or mammary papilla in mouth, and did not correlate with the breast or artificial feeding patterns. The occurrence rate of infant nursing bottle caries was significantly lower in the infants with oral health behavior than those without oral health behavior. After feeding food, more parents feed the infants with little plain boiled water than clean the infant oral cavity with finger cap wet carbasus. 56.7% of parents had no acknowledge of danger of infant nursing bottle caries. There is some correlation between the infant nursing bottle caries and the feeding patterns, oral health behavior, parents' oral health information.

  11. Nondeterministic wave-based methods for low- and mid-frequency response analysis of acoustic field with limited information

    Science.gov (United States)

    Xia, Baizhan; Yin, Hui; Yu, Dejie

    2017-02-01

    The response of the acoustic field, especially for the mid-frequency response, is very sensitive to uncertainties rising from manufacturing/construction tolerances, aggressive environmental factors and unpredictable excitations. To quantify these uncertainties with limited information effectively, two nondeterministic models (the interval model and the hybrid probability-interval model) are introduced. And then, two corresponding nondeterministic numerical methods are developed for the low- and mid-frequency response analysis of the acoustic field under these two nondeterministic models. The first one is the interval perturbation wave-based method (IPWBM) which is proposed to predict the maximal values of the low- and mid-frequency responses of the acoustic field under the interval model. The second one is the hybrid perturbation wave-based method (HPWBM) which is proposed to predict the maximal values of expectations and standard variances of the low- and mid-frequency responses of the acoustic field under the hybrid probability-interval model. The effectiveness and efficiency of the proposed nondeterministic numerical methods for the low- and mid-frequency response analysis of the acoustic field under the interval model and the hybrid probability-interval model are investigated by a numerical example.

  12. Use and abuse of the Fisher information matrix in the assessment of gravitational-wave parameter-estimation prospects

    Science.gov (United States)

    Vallisneri, Michele

    2008-02-01

    The Fisher-matrix formalism is used routinely in the literature on gravitational-wave detection to characterize the parameter-estimation performance of gravitational-wave measurements, given parametrized models of the waveforms, and assuming detector noise of known colored Gaussian distribution. Unfortunately, the Fisher matrix can be a poor predictor of the amount of information obtained from typical observations, especially for waveforms with several parameters and relatively low expected signal-to-noise ratios (SNR), or for waveforms depending weakly on one or more parameters, when their priors are not taken into proper consideration. In this paper I discuss these pitfalls; show how they occur, even for relatively strong signals, with a commonly used template family for binary-inspiral waveforms; and describe practical recipes to recognize them and cope with them. Specifically, I answer the following questions: (i) What is the significance of (quasi-)singular Fisher matrices, and how must we deal with them? (ii) When is it necessary to take into account prior probability distributions for the source parameters? (iii) When is the signal-to-noise ratio high enough to believe the Fisher-matrix result? In addition, I provide general expressions for the higher-order, beyond-Fisher-matrix terms in the 1/SNR expansions for the expected parameter accuracies.

  13. Patterns of Information Use, Avoidance and Evaluation in a Corporate Engineering Environment.

    Science.gov (United States)

    Cool, Collen; Xie, Hong

    2000-01-01

    Examines the communication and information use environment of a corporate engineering community. Highlights include typical work practices; the accessibility of communication and information resources; frequency of use; satisfaction with use in seeking information; and the influence of trust and credibility in using the World Wide Web and human…

  14. Stochastic process of pragmatic information for 2D spiral wave turbulence in globally and locally coupled Alief-Panfilov oscillators

    Science.gov (United States)

    Kuwahara, Jun; Miyata, Hajime; Konno, Hidetoshi

    2017-09-01

    Recently, complex dynamics of globally coupled oscillators have been attracting many researcher's attentions. In spite of their numerous studies, their features of nonlinear oscillator systems with global and local couplings in two-dimension (2D) are not understood fully. The paper focuses on 2D states of coherent, clustered and chaotic oscillation especially under the effect of negative global coupling (NGC) in 2D Alief-Panfilov model. It is found that the tuning NGC can cause various new coupling-parameter dependency on the features of oscillations. Then quantitative characterization of various states of oscillations (so called spiral wave turbulence) is examined by using the pragmatic information (PI) which have been utilized in analyzing multimode laser, solar activity and neuronal systems. It is demonstrated that the dynamics of the PI for various oscillations can be characterized successfully by the Hyper-Gamma stochastic process.

  15. Exploring Human Mobility Patterns Based on Location Information of US Flights

    CERN Document Server

    Jiang, Bin

    2011-01-01

    A range of early studies have been conducted to illustrate human mobility patterns using different tracking data, such as dollar notes, cell phones and taxicabs. Here, we explore human mobility patterns based on massive tracking data of US flights. Both topological and geometric properties are examined in detail. We found that topological properties, such as traffic volume (between airports) and degree of connectivity (of individual airports), including both in- and outdegrees, follow a power law distribution but not a geometric property like travel lengths. The travel lengths exhibit an exponential distribution rather than a power law with an exponential cutoff as previous studies illustrated. We further simulated human mobility on the established topologies of airports with various moving behaviors and found that the mobility patterns are mainly attributed to the underlying binary topology of airports and have little to do with other factors, such as moving behaviors and geometric distances. Apart from the ...

  16. Recognizing lexical and semantic change patterns in evolving life science ontologies to inform mapping adaptation.

    Science.gov (United States)

    Dos Reis, Julio Cesar; Dinh, Duy; Da Silveira, Marcos; Pruski, Cédric; Reynaud-Delaître, Chantal

    2015-03-01

    Mappings established between life science ontologies require significant efforts to maintain them up to date due to the size and frequent evolution of these ontologies. In consequence, automatic methods for applying modifications on mappings are highly demanded. The accuracy of such methods relies on the available description about the evolution of ontologies, especially regarding concepts involved in mappings. However, from one ontology version to another, a further understanding of ontology changes relevant for supporting mapping adaptation is typically lacking. This research work defines a set of change patterns at the level of concept attributes, and proposes original methods to automatically recognize instances of these patterns based on the similarity between attributes denoting the evolving concepts. This investigation evaluates the benefits of the proposed methods and the influence of the recognized change patterns to select the strategies for mapping adaptation. The summary of the findings is as follows: (1) the Precision (>60%) and Recall (>35%) achieved by comparing manually identified change patterns with the automatic ones; (2) a set of potential impact of recognized change patterns on the way mappings is adapted. We found that the detected correlations cover ∼66% of the mapping adaptation actions with a positive impact; and (3) the influence of the similarity coefficient calculated between concept attributes on the performance of the recognition algorithms. The experimental evaluations conducted with real life science ontologies showed the effectiveness of our approach to accurately characterize ontology evolution at the level of concept attributes. This investigation confirmed the relevance of the proposed change patterns to support decisions on mapping adaptation. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Labour standards application in the informal economy of Ghana: The patterns and pressures

    Directory of Open Access Journals (Sweden)

    Akorsu Angela D.

    2013-01-01

    Full Text Available In spite of the rapid growth and importance of informal employment in Ghana, few studies have investigated the extent of coverage of labour standards application, as a form of labour market regulation. This paper investigates the extent of labour standards application in shaping the employment relations and conditions within the informal economy. The study focuses on 30 manufacturing firms in Ghana’s informal economy. Data were obtained through interviews with 43 entrepreneurs and their workers, as well as with key informants from the social partners of industrial relations. The study shows that labour standards are generally not applied among informal economy operators due to factors such as a lack of coverage of the existing labour legislation, ineffective enforcement, ignorance, peculiarities of work organisation, and the dynamics of the apprenticeship system. It is therefore concluded that informal economy workers, who constitute the majority of the workforce in Ghana, lack social protection and must be targeted for intervention.

  18. Brain-based decoding of mentally imagined film clips and sounds reveals experience-based information patterns in film professionals.

    Science.gov (United States)

    de Borst, Aline W; Valente, Giancarlo; Jääskeläinen, Iiro P; Tikka, Pia

    2016-04-01

    In the perceptual domain, it has been shown that the human brain is strongly shaped through experience, leading to expertise in highly-skilled professionals. What has remained unclear is whether specialization also shapes brain networks underlying mental imagery. In our fMRI study, we aimed to uncover modality-specific mental imagery specialization of film experts. Using multi-voxel pattern analysis we decoded from brain activity of professional cinematographers and sound designers whether they were imagining sounds or images of particular film clips. In each expert group distinct multi-voxel patterns, specific for the modality of their expertise, were found during classification of imagery modality. These patterns were mainly localized in the occipito-temporal and parietal cortex for cinematographers and in the auditory cortex for sound designers. We also found generalized patterns across perception and imagery that were distinct for the two expert groups: they involved frontal cortex for the cinematographers and temporal cortex for the sound designers. Notably, the mental representations of film clips and sounds of cinematographers contained information that went beyond modality-specificity. We were able to successfully decode the implicit presence of film genre from brain activity during mental imagery in cinematographers. The results extend existing neuroimaging literature on expertise into the domain of mental imagery and show that experience in visual versus auditory imagery can alter the representation of information in modality-specific association cortices.

  19. Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

    Science.gov (United States)

    Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

    2016-05-17

    Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

  20. Dietary patterns in transition can inform health risk, but detailed assessments are needed to guide recommendations

    Science.gov (United States)

    Most research on diet and health has historically focused on single nutrients or foods and their effect on disease outcomes. In recent years, this focus has shifted to include the total dietary pattern as a risk factor in epidemiologic studies. This change has occurred for several reasons. First, as...

  1. Spatiotemporal chaos involving wave instability

    Science.gov (United States)

    Berenstein, Igal; Carballido-Landeira, Jorge

    2017-01-01

    In this paper, we investigate pattern formation in a model of a reaction confined in a microemulsion, in a regime where both Turing and wave instability occur. In one-dimensional systems, the pattern corresponds to spatiotemporal intermittency where the behavior of the systems alternates in both time and space between stationary Turing patterns and traveling waves. In two-dimensional systems, the behavior initially may correspond to Turing patterns, which then turn into wave patterns. The resulting pattern also corresponds to a chaotic state, where the system alternates in both space and time between standing wave patterns and traveling waves, and the local dynamics may show vanishing amplitude of the variables.

  2. Energy loss of terahertz electromagnetic waves by nano-sized connections in near-self-complementary metallic checkerboard patterns

    Science.gov (United States)

    Takano, Keisuke; Tanaka, Yoku; Moreno, Gabriel; Chahadih, Abdallah; Ghaddar, Abbas; Han, Xiang-Lei; Vaurette, François; Nakata, Yosuke; Miyamaru, Fumiaki; Nakajima, Makoto; Hangyo, Masanori; Akalin, Tahsin

    2017-08-01

    The design of a self-complementary metallic checkerboard pattern achieves broadband, dispersion-less, and maximized absorption, concentrating in deep subwavelength resistive connections between squares, without any theoretical limitation on the energy absorbing area. Here, we experimentally and numerically investigate the electromagnetic response in the limit of extremely small connections. We show that finite conductivity and randomness in a near-self-complementary checkerboard pattern play a crucial role in producing a frequency-independent energy loss in the terahertz frequency region. Here, metals behave like an almost perfect conductor. When the checkerboard pattern approaches the perfect self-complementary pattern, the perfect conductor approximation spontaneously breaks down, owing to the finite conductivity at the nano-scale connection, leading to broadband absorption. It is also shown that the random connections between metallic squares also lead to broadband and maximized energy loss through scattering loss, similar to finite conductivity.

  3. Asymmetric coupling and dispersion of surface-plasmon-polariton waves on a periodically patterned anisotropic metal film

    OpenAIRE

    Dutta, Jhuma; Ramakrishna, S. Anantha; Lakhtakia, Akhlesh

    2014-01-01

    The morphology of a columnar thin film (CTF) of silver renders it an effectively biaxially anisotropic continuum. CTFs of silver deposited on one-dimensional gratings of photoresist showed strong blazing action and asymmetrically coupled optical radiation to surface plasmon-polariton (SPP) waves propagating only along one direction supported by either the CTF/photoresist or the CTF/air interfaces. Homogenization of the CTFs using the Bruggeman formalism revealed them to display hyperbolic dis...

  4. A Comparison of Participation Patterns in Selected Formal, Non-Formal, and Informal Online Learning Environments

    Science.gov (United States)

    Schwier, Richard A.; Seaton, J. X.

    2013-01-01

    Does learner participation vary depending on the learning context? Are there characteristic features of participation evident in formal, non-formal, and informal online learning environments? Six online learning environments were chosen as epitomes of formal, non-formal, and informal learning contexts and compared. Transcripts of online…

  5. Social Information Processing Patterns, Social Skills, and School Readiness in Preschool Children

    Science.gov (United States)

    Ziv, Yair

    2013-01-01

    The links among social information processing, social competence, and school readiness were examined in this short-term longitudinal study with a sample of 198 preschool children. Data on social information processing were obtained via child interview, data on child social competence were obtained via teacher report, and data on school readiness…

  6. A heat wave during leaf expansion severely reduces productivity and modifies seasonal growth patterns in a northern hardwood forest.

    Science.gov (United States)

    Stangler, Dominik Florian; Hamann, Andreas; Kahle, Hans-Peter; Spiecker, Heinrich

    2016-10-13

    A useful approach to monitor tree response to climate change and environmental extremes is the recording of long-term time series of stem radial variations obtained with precision dendrometers. Here, we study the impact of environmental stress on seasonal growth dynamics and productivity of yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh.) in the Great Lakes, St Lawrence forest region of Ontario. Specifically, we research the effects of a spring heat wave in 2010, and a summer drought in 2012 that occurred during the 2005-14 study period. We evaluated both growth phenology (onset, cessation, duration of radial growth, time of maximum daily growth rate) and productivity (monthly and seasonal average growth rates, maximum daily growth rate, tree-ring width) and tested for differences and interactions among species and years. Productivity of sugar maple was drastically compromised by a 3-day spring heat wave in 2010 as indicated by low growth rates, very early growth cessation and a lagged growth onset in the following year. Sugar maple also responded more sensitively than yellow birch to a prolonged drought period in July 2012, but final tree-ring width was not significantly reduced due to positive responses to above-average temperatures in the preceding spring. We conclude that sugar maple, a species that currently dominates northern hardwood forests, is vulnerable to heat wave disturbances during leaf expansion, which might occur more frequently under anticipated climate change.

  7. Gain and far-field patterns for phase-correcting Fresnel zone plate antennas at millimeter-wave and terahertz frequencies

    Science.gov (United States)

    Wiltse, James C.

    2007-04-01

    The Fresnel zone plate lens antenna, which provides advantages compared to a normal paraboloidal or spherical lens, has been extensively investigated in the millimeter-wave and terahertz regions. The advantages include reduced weight, volume, and attenuation and simplicity of design. The principal disadvantage is that the zone plate sometimes provides reduced gain compared to a true lens. Particularly at high millimeter-wave or terahertz frequencies the low loss of the zone plate more than compensates for the reduced directivity. This paper investigates the gains and far-field patterns for a number of cases and gives both the analysis and numerical results for the examples. These cases have dealt with large-angle designs, where the focal length (F) and diameter (D) are comparable (F/D = 0.3 to 2.5), unlike the typical optical examples. The antenna patterns are found to have beamwidths and first sidelobes that are similar to what one would obtain with a standard lens, given the same aperture illumination. Appropriate feed designs are also described. For best aperture efficiency the illumination taper is about 10 dB, and this gives first sidelobe levels of about -24dB for a circular aperture. Far-out average sidelobes are not as low as for a true lens, and this is where the gain is affected.

  8. Non-Markovian dynamics for an open two-level system without rotating wave approximation: indivisibility versus backflow of information

    Science.gov (United States)

    Zeng, H. S.; Tang, N.; Zheng, Y. P.; Xu, T. T.

    2012-10-01

    By use of the recently presented two measures, the indivisibility and the backflow of information, we study the non-Markovianity of the dynamics for a two-level system interacting with a zero-temperature structured environment without using rotating wave approximation (RWA). In the limit of weak coupling between the system and its reservoir, and by expanding the time-convolutionless (TCL) generator to the forth order with respect to the coupling strength, the time-local non-Markovian master equation for the reduced state of the system is derived. Under the secular approximation, the exact analytic solution is obtained and the sufficient and necessary conditions for the indivisibility and the backflow of information for the system dynamics are presented. In the more general case, we investigate numerically the properties of the two measures for the case of Lorentzian reservoir. Our results show the importance of the counter-rotating terms to the short-time-scale non-Markovian behavior of the system dynamics, further expose the relation between the two measures and their rationality as non-Markovian measures. Finally, the complete positivity of the dynamics of the considered system is discussed.

  9. Studies of the phase gradient at the boundary of the phase diffusion equation, motivated by peculiar wave patterns of rhythmic contraction in the amoeboid movement of Physarum polycephalum

    Science.gov (United States)

    Iima, Makoto; Kori, Hiroshi; Nakagaki, Toshiyuki

    2017-04-01

    The boundary of a cell is the interface with its surroundings and plays a key role in controlling the cell movement adaptations to different environments. We propose a study of the boundary effects on the patterns and waves of the rhythmic contractions in plasmodia of Physarum polycephalum, a tractable model organism of the amoeboid type. Boundary effects are defined as the effects of both the boundary conditions and the boundary shape. The rhythmicity of contraction can be modulated by local stimulation of temperature, light and chemicals, and by local deformation of cell shape via mechanosensitive ion channels as well. First, we examined the effects of boundary cell shapes in the case of a special shape resembling a tadpole, while requiring that the natural frequency in the proximity of the boundary is slightly higher and uniform. The simulation model reproduced the approximate propagated wave, from the tail to the head, while the inward waves were observed only near the periphery of the head section of the tadpole-shape. A key finding was that the frequency of the rhythmic contractions depended on the local shape of cell boundary. This implies that the boundary conditions of the phase were not always homogeneous. To understand the dependency, we reduced the two-dimensional model into a one-dimensional continuum model with Neumann boundary conditions. Here, the boundary conditions reflect the frequency distribution at the boundary. We described the analytic solutions and calculated the relationship between the boundary conditions and the wave propagation for a one-dimensional model of the continuous oscillatory field and a discrete coupled oscillator system. The results obtained may not be limited to cell movement of Physarum, but may be applicable to the other physical systems since the analysis used a generic phase diffusion equation.

  10. Geophysical information for teachers: Wave tanks, homemade clouds, glacial goo, and more!

    Science.gov (United States)

    Adamec, Bethany Holm

    2012-02-01

    AGU is deeply committed to fostering the next generation of Earth and space scientists. Union activities contribute to this effort in many ways, one of which is partnering with the National Earth Science Teacher's Association (NESTA) to hold the Annual Geophysical Information for Teachers (GIFT) workshop at AGU's annual Fall Meeting. GIFT allows K-12 science teachers to hear about the latest geoscience research from the scientists making the discoveries, explore new classroom resources for their students, and visit exhibits and technical sessions of the AGU meeting for free. In 2011 AGU worked with NESTA to develop an improved rigorous and open application process for scientists and education professionals who wished to work as a team and present their Earth and space science work to teachers, as well as lead the educators in a hands-on, classroom- ready activity. Twenty-four applications were received for five slots, so the selected presentations (on tsunamis, clouds, field campaigns, glaciers, and volcanoes), chosen through a peer- review process, truly represented the best ways of getting cutting-edge science into the classroom.

  11. Spot Matching of 2-DE Images Using Distance, Intensity, and Pattern Information.

    Science.gov (United States)

    Xin, Hua-Mei; Zhu, Yuemin

    2016-01-01

    The analysis of a large number of two-dimensional gel electrophoresis (2-DE) images requires developing automatic methods. In such analyses, spot matching plays a fundamental role, in particular for the identification of proteins. We describe a simple and accurate method which allows to automatically and accurately match spots in 2-DE images. The method consists of simultaneously exploiting the distance between the spots, their intensity, and the pattern formed by their spatial configuration.

  12. Information resources and the correlation of response patterns between biological end points

    Energy Technology Data Exchange (ETDEWEB)

    Malling, H.V. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Wassom, J.S. [Oak Ridge National Laboratory, TN (United States)

    1990-12-31

    This paper focuses on the analysis of information for mutagenesis, a biological end point that is important in the overall process of assessing possible adverse health effects from chemical exposure. 17 refs.

  13. Health marketing information: an assessment of past and future utilization patterns.

    Science.gov (United States)

    McSurely, H B; Fullerton, S

    1995-01-01

    A sample of 108 members of the Academy of Health Services Marketing provided bibliographic citations of 629 sources of information which have been important to them in their jobs. The results indicate that the propensity to rely upon a source is dependent upon the topic of the information sought. The sources under scrutiny were consultants, books, journals, magazines, seminars, conferences, video tapes, and audio tapes. The topics considered included the variables of the marketing mix as well as market planning and marketing research. The discussion provides insight about where seekers of health care marketing knowledge go for specific kinds of information. It also suggests types of media that information-providers should consider for dissemination of their material.

  14. Forging patterns and making waves from biology to geology: a commentary on Turing (1952) 'The chemical basis of morphogenesis'.

    Science.gov (United States)

    Ball, Philip

    2015-04-19

    Alan Turing was neither a biologist nor a chemist, and yet the paper he published in 1952, 'The chemical basis of morphogenesis', on the spontaneous formation of patterns in systems undergoing reaction and diffusion of their ingredients has had a substantial impact on both fields, as well as in other areas as disparate as geomorphology and criminology. Motivated by the question of how a spherical embryo becomes a decidedly non-spherical organism such as a human being, Turing devised a mathematical model that explained how random fluctuations can drive the emergence of pattern and structure from initial uniformity. The spontaneous appearance of pattern and form in a system far away from its equilibrium state occurs in many types of natural process, and in some artificial ones too. It is often driven by very general mechanisms, of which Turing's model supplies one of the most versatile. For that reason, these patterns show striking similarities in systems that seem superficially to share nothing in common, such as the stripes of sand ripples and of pigmentation on a zebra skin. New examples of 'Turing patterns' in biology and beyond are still being discovered today. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

  15. Optimization of numerical weather/wave prediction models based on information geometry and computational techniques

    Science.gov (United States)

    Galanis, George; Famelis, Ioannis; Kalogeri, Christina

    2014-10-01

    The last years a new highly demanding framework has been set for environmental sciences and applied mathematics as a result of the needs posed by issues that are of interest not only of the scientific community but of today's society in general: global warming, renewable resources of energy, natural hazards can be listed among them. Two are the main directions that the research community follows today in order to address the above problems: The utilization of environmental observations obtained from in situ or remote sensing sources and the meteorological-oceanographic simulations based on physical-mathematical models. In particular, trying to reach credible local forecasts the two previous data sources are combined by algorithms that are essentially based on optimization processes. The conventional approaches in this framework usually neglect the topological-geometrical properties of the space of the data under study by adopting least square methods based on classical Euclidean geometry tools. In the present work new optimization techniques are discussed making use of methodologies from a rapidly advancing branch of applied Mathematics, the Information Geometry. The latter prove that the distributions of data sets are elements of non-Euclidean structures in which the underlying geometry may differ significantly from the classical one. Geometrical entities like Riemannian metrics, distances, curvature and affine connections are utilized in order to define the optimum distributions fitting to the environmental data at specific areas and to form differential systems that describes the optimization procedures. The methodology proposed is clarified by an application for wind speed forecasts in the Kefaloniaisland, Greece.

  16. Locating Sensors for Detecting Source-to-Target Patterns of Special Nuclear Material Smuggling: A Spatial Information Theoretic Approach

    Directory of Open Access Journals (Sweden)

    Xuesong Zhou

    2010-08-01

    Full Text Available In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

  17. Locating sensors for detecting source-to-target patterns of special nuclear material smuggling: a spatial information theoretic approach.

    Science.gov (United States)

    Przybyla, Jay; Taylor, Jeffrey; Zhou, Xuesong

    2010-01-01

    In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM) smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

  18. Evolving Consumption Patterns of Various Information Media via Handheld Mobile Devices

    Directory of Open Access Journals (Sweden)

    Nitza Geri

    2015-06-01

    Full Text Available This study examines diverse information media in order to identify those formats that are most suitable for consumption via handheld mobile devices, namely, smartphones and tablets. The preferences of the users are measured objectively by analyzing actual data of their relative use of handheld mobile devices and personal computing (PC desktop devices, including laptops and notebooks, for consumption of information presented in various formats. Our findings are based on Google Analytics pageview data of five course Websites during a period of three semesters, by 11,557 undergraduate students. M-learning contexts were chosen, since in a learning environment the interests of information providers (i.e., the instructors are in accord with those of the information consumers (i.e., the students, whereas in commercial settings there may be conflicts of interests. Our findings demonstrate that although about 90% of the pageviews were via PC devices, the rate of smartphone use for consuming learning content in diverse information media is gradually increasing as time goes by, whereas the rate of tablet use for these purposes is stagnant. The most promising direction for smartphone development, emanating from the findings, is online video content.

  19. Wanna know about vaping? Patterns of message exposure, seeking and sharing information about e-cigarettes across media platforms.

    Science.gov (United States)

    Emery, Sherry L; Vera, Lisa; Huang, Jidong; Szczypka, Glen

    2014-07-01

    Awareness and use of electronic cigarettes has rapidly grown in the USA recently, in step with increased product marketing. Using responses to a population survey of US adults, we analysed demographic patterns of exposure to, searching for and sharing of e-cigarette-related information across media platforms. An online survey of 17,522 US adults was conducted in 2013. The nationally representative sample was drawn from GfK Group's KnowledgePanel plus off-panel recruitment. Fixed effects logit models were applied to analyse relationships between exposure to, searching for and sharing of e-cigarette-related information and demographic characteristics, e-cigarette and tobacco use, and media behaviours. High levels of awareness about e-cigarettes were indicated (86% aware; 47% heard through media channels). Exposure to e-cigarette-related information was associated with tobacco use, age, gender, more education, social media use and time spent online. Although relatively small proportions of the sample had searched for (∼5%) or shared (∼2%) e-cigarette information, our analyses indicated demographic patterns to those behaviours. Gender, high income and using social media were associated with searching for e-cigarette information; lesbian, gay and bisexual and less education were associated with sharing. Current tobacco use, age, being Hispanic and time spent online were associated with both searching and sharing. US adults are widely exposed to e-cigarette marketing through the media; such marketing may differentially target specific demographic groups. Further research should longitudinally examine how exposure to, searching for and sharing of e-cigarette information relate to subsequent use of e-cigarettes and/or combustible tobacco. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Changing Patterns in the Impact of Information on Party Choice in a Multiparty System

    DEFF Research Database (Denmark)

    Hansen, Kasper Møller

    2009-01-01

    Election Studies. In both multiparty elections, the impact of information has significant consequences for party choice. In 1971, political knowledge seems to be the variable connecting class with party choice, whereas political knowledge seems to be the variable connecting issues with party choice in 2005....... The information effects are greater than the effects observed in similar analyses of the American two-party system, thus suggesting a positive relationship between the number of parties and the impact of political knowledge. Finally, the analysis supports the notion that right-leaning parties tend to fare better...

  1. Patterns beyond Faraday waves: observation of parametric crossover from Faraday instabilities to the formation of vortex lattices in open dual fluid strata

    Science.gov (United States)

    Ohlin, Kjell; Berggren, Karl Fredrik

    2016-07-01

    Faraday first characterised the behaviour of a fluid in a container subjected to vertical periodic oscillations. His study pertaining to hydrodynamic instability, the ‘Faraday instability’, has catalysed a myriad of experimental, theoretical, and numerical studies shedding light on the mechanisms responsible for the transition of a system at rest to a new state of well-ordered vibrational patterns at fixed frequencies. Here we study dual strata in a shallow vessel containing distilled water and high-viscosity lubrication oil on top of it. At elevated driving power, beyond the Faraday instability, the top stratum is found to ‘freeze’ into a rigid pattern with maxima and minima. At the same time there is a dynamic crossover into a new state in the form of a lattice of recirculating vortices in the lower layer containing the water. Instrumentation and the physics behind are analysed in a phenomenological way together with a basic heuristic modelling of the wave field. The study, which is based on relatively low-budget equipment, stems from related art projects that have evolved over the years. The study is of value within basic research as well as in education, especially as more advanced collective project work in e.g. engineering physics, where it invites further studies of pattern formation, the emergence of vortex lattices and complexity.

  2. Online Health Information Seeking Pattern Among Undergraduates in a Nigerian University

    Directory of Open Access Journals (Sweden)

    Oluwaseun I. Obasola

    2016-03-01

    Full Text Available Based on a cross-sectional design, this study investigates online health seeking and its possible influence on decision making among 400 university undergraduates in Nigeria. From the results, it was found that daily Internet use was on the average (33.7%, and use was constrained by the poor power supply, the high cost of the Internet access, and poor delivery of services. Health information sought covers nutrition, fitness/exercise, HIV/AIDS, malaria, sore throat, mental health, menstrual pain, and sexual/reproductive health. The majority (72.7% who perceived available health information as accurate and dependable had an opportunity to seek similar information on their health conditions from different online sources. A high proportion (202 claimed that they consulted a physician after that, just a few (54 of the respondents consulted a traditional healer, and a few others relied on self-medication (10% or asked friends for suggestions (11%. Thus, there is a need to provide reliable Internet connection and enlighten the Nigerian youth on criteria for assessing quality online health information.

  3. Future urbanization patterns: in the Netherlands under the influence of information and communication technologies

    NARCIS (Netherlands)

    Muhammad, S.

    2007-01-01

    Computer-based Information and Communication Technologies (ICTs) are revolutionary in that they change the meaning of distance and accessibility in society. People can now access opportunities (jobs, shopping, education, recreation etc.) in virtual space in a matter of seconds, which in physical spa

  4. Future urbanization patterns: in the Netherlands under the influence of information and communication technologies

    NARCIS (Netherlands)

    Muhammad, S.

    2007-01-01

    Computer-based Information and Communication Technologies (ICTs) are revolutionary in that they change the meaning of distance and accessibility in society. People can now access opportunities (jobs, shopping, education, recreation etc.) in virtual space in a matter of seconds, which in physical

  5. Urban Spatial Pattern and Interaction based on Analysis of Nighttime Remote Sensing Data and Geo-social Media Information

    Science.gov (United States)

    Ratnasari, Nila; Dwi Candra, Erika; Herdianta Saputra, Defa; Putra Perdana, Aji

    2016-11-01

    Urban development in Indonesia significantly incerasing in line with rapid development of infrastructure, utility, and transportation network. Recently, people live depend on lights at night and social media and these two aspects can depicted urban spatial pattern and interaction. This research used nighttime remote sensing data with the VIIRS (Visible Infrared Imaging Radiometer Suite) day-night band detects lights, gas flares, auroras, and wildfires. Geo-social media information derived from twitter data gave big picture on spatial interaction from the geospatial footprint. Combined both data produced comprehensive urban spatial pattern and interaction in general for Indonesian territory. The result is shown as a preliminary study of integrating nighttime remote sensing data and geospatial footprint from twitter data.

  6. Extracting multiscale pattern information of fMRI based functional brain connectivity with application on classification of autism spectrum disorders.

    Directory of Open Access Journals (Sweden)

    Hui Wang

    Full Text Available We employed a multi-scale clustering methodology known as "data cloud geometry" to extract functional connectivity patterns derived from functional magnetic resonance imaging (fMRI protocol. The method was applied to correlation matrices of 106 regions of interest (ROIs in 29 individuals with autism spectrum disorders (ASD, and 29 individuals with typical development (TD while they completed a cognitive control task. Connectivity clustering geometry was examined at both "fine" and "coarse" scales. At the coarse scale, the connectivity clustering geometry produced 10 valid clusters with a coherent relationship to neural anatomy. A supervised learning algorithm employed fine scale information about clustering motif configurations and prevalence, and coarse scale information about intra- and inter-regional connectivity; the algorithm correctly classified ASD and TD participants with sensitivity of 82.8% and specificity of 82.8%. Most of the predictive power of the logistic regression model resided at the level of the fine-scale clustering geometry, suggesting that cellular versus systems level disturbances are more prominent in individuals with ASD. This article provides validation for this multi-scale geometric approach to extracting brain functional connectivity pattern information and for its use in classification of ASD.

  7. Extracting multiscale pattern information of fMRI based functional brain connectivity with application on classification of autism spectrum disorders.

    Science.gov (United States)

    Wang, Hui; Chen, Chen; Fushing, Hsieh

    2012-01-01

    We employed a multi-scale clustering methodology known as "data cloud geometry" to extract functional connectivity patterns derived from functional magnetic resonance imaging (fMRI) protocol. The method was applied to correlation matrices of 106 regions of interest (ROIs) in 29 individuals with autism spectrum disorders (ASD), and 29 individuals with typical development (TD) while they completed a cognitive control task. Connectivity clustering geometry was examined at both "fine" and "coarse" scales. At the coarse scale, the connectivity clustering geometry produced 10 valid clusters with a coherent relationship to neural anatomy. A supervised learning algorithm employed fine scale information about clustering motif configurations and prevalence, and coarse scale information about intra- and inter-regional connectivity; the algorithm correctly classified ASD and TD participants with sensitivity of 82.8% and specificity of 82.8%. Most of the predictive power of the logistic regression model resided at the level of the fine-scale clustering geometry, suggesting that cellular versus systems level disturbances are more prominent in individuals with ASD. This article provides validation for this multi-scale geometric approach to extracting brain functional connectivity pattern information and for its use in classification of ASD.

  8. Patterns of bird-window collisions inform mitigation on a university campus

    Directory of Open Access Journals (Sweden)

    Natalia Ocampo-Peñuela

    2016-02-01

    Full Text Available Bird-window collisions cause an estimated one billion bird deaths annually in the United States. Building characteristics and surrounding habitat affect collision frequency. Given the importance of collisions as an anthropogenic threat to birds, mitigation is essential. Patterned glass and UV-reflective films have been proven to prevent collisions. At Duke University’s West campus in Durham, North Carolina, we set out to identify the buildings and building characteristics associated with the highest frequencies of collisions in order to propose a mitigation strategy. We surveyed six buildings, stratified by size, and measured architectural characteristics and surrounding area variables. During 21 consecutive days in spring and fall 2014, and spring 2015, we conducted carcass surveys to document collisions. In addition, we also collected ad hoc collision data year-round and recorded the data using the app iNaturalist. Consistent with previous studies, we found a positive relationship between glass area and collisions. Fitzpatrick, the building with the most window area, caused the most collisions. Schwartz and the Perk, the two small buildings with small window areas, had the lowest collision frequencies. Penn, the only building with bird deterrent pattern, caused just two collisions, despite being almost completely made out of glass. Unlike many research projects, our data collection led to mitigation action. A resolution supported by the student government, including news stories in the local media, resulted in the application of a bird deterrent film to the building with the most collisions: Fitzpatrick. We present our collision data and mitigation result to inspire other researchers and organizations to prevent bird-window collisions.

  9. Patterns of ownership and accessibility to information and media facilities in democratizing the media in Nigeria.

    Science.gov (United States)

    Okwudishu, C

    1988-01-01

    Nigeria needs to embrace technology and pursue private media ownership in order to achieve a democratic media. In recent years, mass media in Africa has become a force with augmenting power that has influenced government and regimes. A democratization of the African media is reliant on media ownership and accessibility of information. Within Nigeria, there is a government monopoly of the media and therefore a road block in the free flow of information. As well, Nigeria's current economic situation has made media accessibility an extravagance. The electronic media is far from effective as many areas have poor reception, no electricity, or face a language barrier. Because most of the print media is written in English, many Nigerians cannot comprehend the printed news.

  10. Rates and patterns of deforestation in the Philippines: application of geographic information system analysis

    Science.gov (United States)

    Dawning S. Lui; Louis R. Iverson; Sandra Brown

    1993-01-01

    Land-use maps for 1934 and 1988, and a 1941 road map of the Philippines were digitized into a geographic information system. These maps were then analyzed to determine the rates of deforestation and their relationship with factors such as the distance of forests to roads and forest fragmentation (measured by perimeter-to-area ratio (P/A ratio) of forest patches) for...

  11. Future urbanization patterns: in the Netherlands under the influence of information and communication technologies

    OpenAIRE

    Muhammad, S.

    2007-01-01

    Computer-based Information and Communication Technologies (ICTs) are revolutionary in that they change the meaning of distance and accessibility in society. People can now access opportunities (jobs, shopping, education, recreation etc.) in virtual space in a matter of seconds, which in physical space would have needed hours of travelling. But still due to the nature of opportunities and human need to have face to face contact, majority of the opportunities are being accessed in physical spac...

  12. The role of information and trading volume on intradaily and weekly returns patterns in the Spanish stock market

    OpenAIRE

    1996-01-01

    The aim of this work is to document new results about intradaily and weekly effects in the Spanish stock market, relating the returns in the stock index, during trading and non trading hours, to the arrival of information and daily trading volume. Weekly and intraday patterns are examined using the index Ibex-35 transaction data. Twenty-three months oftransaction records of the Ibex-35, at 15-minutes intervals, were examined in an attempt to better understand the dayof-the week effect and tra...

  13. EMS wave logger data processing

    NARCIS (Netherlands)

    Verhagen, H.J.

    2013-01-01

    Waves can be measured in several ways. One way of measuring waves is by measuring the wave pressure at a certain depth using a pressure sensor and calculate the wave information from the pressure record. The EMS wave logger uses a Honeywell MLH 050 PGP 06A pressure sensor. The information is stored

  14. Cognitive patterns of neuroanatomy concepts: Knowledge organizations that emerge from problem solving versus information gathering

    Science.gov (United States)

    Weidner, Jeanne Margaret O'malley

    2000-10-01

    This study was motivated by some of the claims that are found in the literature on Problem-Based Learning (PBL). This instructional technique, which uses case studies as its primary instructional tool, has been advanced as an alternative to traditional instruction in order to foster more meaningful, integrative learning of scientific concepts. Several of the advantages attributed to Problem-Based Learning are that it (1) is generally preferred by students because it appears to foster a more nurturing and enjoyable learning experience, (2) fosters greater retention of knowledge and concepts acquired, and (3) results in increased ability to apply this knowledge toward solving new problems. This study examines the differences that result when students learn neuroanatomy concepts under two instructional contexts: problem solving vs. information gathering. The technological resource provided to students to support learning under each of these contexts was the multimedia program BrainStorm: An Interactive Neuroanatomy Atlas (Coppa & Tancred, 1995). The study explores the influence of context with regard to subjects' performance on objective post-tests, organization of knowledge as measured by Pathfinder Networks, differential use of the multimedia software and discourse differences emerging from the transcripts. The findings support previous research in the literature that problem-solving results in less knowledge acquisition in the short term, greater retention of material over time, and a subjects' preference for the method. However, both the degree of retention and preference were influenced by subjects' prior knowledge of the material in the exercises, as there was a significant difference in performance between the two exercises: for the exercise about which subjects appeared to have greater background information, memory decay was less, and subject attitude toward the problem solving instructional format was more favorable, than for the exercise for which subjects

  15. Global warming's five Germanys: A typology of Germans' views on climate change and patterns of media use and information.

    Science.gov (United States)

    Metag, Julia; Füchslin, Tobias; Schäfer, Mike S

    2017-05-01

    People's attitudes toward climate change differ, and these differences may correspond to distinct patterns of media use and information seeking. However, studies extending analyses of attitude types and their specific media diets to countries beyond the United States are lacking. We use a secondary analysis of survey data from Germany to identify attitudes toward climate change among the German public and specify those segments of the population based on their media use and information seeking. Similar to the Global Warming's Six Americas study, we find distinct attitudes (Global Warming's Five Germanys) that differ in climate change-related perceptions as well as in media use and communicative behavior. These findings can help tailor communication campaigns regarding climate change to specific audiences.

  16. Information content in frequency-dependent, multi-offset GPR data for layered media reconstruction using full-wave inversion

    Science.gov (United States)

    De Coster, Albéric; Phuong Tran, Anh; Lambot, Sébastien

    2014-05-01

    Water lost through leaks can represent high percentages of the total production in water supply systems and constitutes an important issue. Leak detection can be tackled with various techniques such as the ground-penetrating radar (GPR). Based on this technology, various procedures have been elaborated to characterize a leak and its evolution. In this study, we focus on a new full-wave radar modelling approach for near-field conditions, which takes into account the antenna effects as well as the interactions between the antenna(s) and the medium through frequency-dependent global transmission and reflection coefficients. This approach is applied to layered media for which 3-D Green's functions can be calculated. The model allows for a quantitative estimation of the properties of multilayered media by using full-wave inversion. This method, however, proves to be limited to provide users with an on-demand assessment as it is generally computationally demanding and time consuming, depending on the medium configuration as well as the number of unknown parameters to retrieve. In that respect, we propose two leads in order to enhance the parameter retrieval step. The first one consists in analyzing the impact of the reduction of the number of frequencies on the information content. For both numerical and laboratory experiments, this operation has been achieved by investigating the response surface topography of objective functions arising from the comparison between measured and modelled data. The second one involves the numerical implementation of multistatic antenna configurations with constant and variable offsets in the model. These two kinds of analyses are then combined in numerical experiments to observe the conjugated effect of the number of frequencies and the offset configuration. To perform the numerical analyses, synthetic Green's functions were simulated for different multilayered medium configurations. The results show that an antenna offset increase leads

  17. Exploring spectral wave climate variability using a weather type approach

    Science.gov (United States)

    Mendez, F.; Espejo, A.; Camus, P.; Losada, I.

    2012-12-01

    Traditional approaches for determining wave climate variability in scales from month to decades have been broadly focused on aggregated or statistical parameters such as significant wave height, wave energy flux or mean wave direction. These studies, although revealing the major general modes of wave climate variability and trends, do not take in consideration the complexity of the gravity wave fields. Because ocean waves are the response of both local and remote winds, analyzing directional full spectrum variability can throw light on atmosphere circulation not only over the immediate ocean region, but also over a more broadly basin-scale. In this work we use the weather type approach (data mining) to explore wave climate variability in the frequency-direction domain. This approach identifies daily to 15 daily synoptic modes (depending on the basin) of the sea level pressure (from NCEP/NCAR) over the effective fetch of one selected ocean point, finding bi-univocal relations between each synoptic pattern (weather type) and each spectral wave energy distribution. Thus, it allows exploring wave spectrum (from GOW reanalisys, WaveWatchIII) covering all temporal scales of variability: daily, monthly, seasonal, inter-annual, decadal, long term trends and future climate change projections. The proposed scheme provides valuable information improving our ocean waves understanding. Moreover this new approach can support offshore wind-wave energy farms optimization or a more rigorous determination of wave induced sediment transport between others applications.

  18. Effects of radiofrequency electromagnetic wave exposure from cellular phones on the reproductive pattern in male Wistar rats.

    Science.gov (United States)

    Kesari, Kavindra Kumar; Kumar, Sanjay; Behari, Jitendra

    2011-06-01

    The present study investigates the effect of free radical formation due to mobile phone exposure and effect on fertility pattern in 70-day-old male Wistar rats (sham exposed and exposed). Exposure took place in Plexiglas cages for 2 h a day for 35 days to mobile phone frequency. The specific absorption rate was estimated to be 0.9 W/kg. An analysis of antioxidant enzymes glutathione peroxidase (P phones might affect the fertilizing potential of spermatozoa.

  19. Patterns of Objective and Subjective Burden of Informal Caregivers in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    E. Bayen

    2015-01-01

    Full Text Available Background. Home care for patients with Multiple Sclerosis (MS relies largely on informal caregivers (ICs. Methods. We assessed ICs objective burden (Resource Utilization in Dementia measuring informal care time (ICT and ICs subjective burden (Zarit Burden Inventory (ZBI. Results. ICs (N=99 were spouses (70%, mean age 52 years, assisting disabled patients with a mean EDSS (Expanded Disability Status Scale of 5.5, with executive dysfunction (mean DEX (Dysexecutive questionnaire of 25 and a duration of MS ranging from 1 to 44 years. Objective burden was high (mean ICT = 6.5 hours/day, mostly consisting of supervision time. Subjective burden was moderate (mean ZBI = 27.3. Multivariate analyses showed that both burdens were positively correlated with higher levels of EDSS and DEX, whereas coresidency and IC’s female gender correlated with objective burden only and IC’s poor mental health status with subjective burden only. When considering MS aggressiveness, it appeared that both burdens were not correlated with a higher duration of MS but rather increased for patients with severe and early dysexecutive function and for patients classified as fast progressors according to the Multiple Sclerosis Severity Score. Conclusion. Evaluation of MS disability course and IC’s personal situation is crucial to understand the burden process and to implement adequate interventions in MS.

  20. iRaster: a novel information visualization tool to explore spatiotemporal patterns in multiple spike trains.

    Science.gov (United States)

    Somerville, J; Stuart, L; Sernagor, E; Borisyuk, R

    2010-12-15

    Over the last few years, simultaneous recordings of multiple spike trains have become widely used by neuroscientists. Therefore, it is important to develop new tools for analysing multiple spike trains in order to gain new insight into the function of neural systems. This paper describes how techniques from the field of visual analytics can be used to reveal specific patterns of neural activity. An interactive raster plot called iRaster has been developed. This software incorporates a selection of statistical procedures for visualization and flexible manipulations with multiple spike trains. For example, there are several procedures for the re-ordering of spike trains which can be used to unmask activity propagation, spiking synchronization, and many other important features of multiple spike train activity. Additionally, iRaster includes a rate representation of neural activity, a combined representation of rate and spikes, spike train removal and time interval removal. Furthermore, it provides multiple coordinated views, time and spike train zooming windows, a fisheye lens distortion, and dissemination facilities. iRaster is a user friendly, interactive, flexible tool which supports a broad range of visual representations. This tool has been successfully used to analyse both synthetic and experimentally recorded datasets. In this paper, the main features of iRaster are described and its performance and effectiveness are demonstrated using various types of data including experimental multi-electrode array recordings from the ganglion cell layer in mouse retina. iRaster is part of an ongoing research project called VISA (Visualization of Inter-Spike Associations) at the Visualization Lab in the University of Plymouth. The overall aim of the VISA project is to provide neuroscientists with the ability to freely explore and analyse their data. The software is freely available from the Visualization Lab website (see www.plymouth.ac.uk/infovis).

  1. The role of shape-from-shading information in the perception of local and global form in Glass patterns.

    Science.gov (United States)

    Khuu, Sieu K; Moreland, Amy; Phu, Jack

    2011-06-28

    Three-dimensional (3D) shape can be inferred from the surface shading gradient of objects. Using Glass patterns, we investigated the importance of shape-from-shading information to the perception of global form. We examined whether different 3D shapes inferred from shading affect the extraction of local dipole orientations (local analysis) and the integration of dipoles in the perception of Glass structure (global analysis). In Experiment 1, we showed that incongruence in shading between partner dots prevents the recovery of the dipole orientation: partner dots with different 3D shapes are not paired to recover the dipole orientation. However, when incongruent "bipartite" partner dots (that have the same contrast polarity as shaded dots, but are two-dimensional) were used, the visual system was able to extract the local dipole orientation and detect the global pattern (Experiment 2). In Experiment 3, we showed that additional noise dipoles affect the detection of Glass structure regardless of the 3D shape difference between signal and additional noise dipoles. This demonstrates that the visual system combines different oriented 3D dipoles to detect Glass structure. Our findings show that shape-from-shading information impacts on the ability to detect form structure but in different ways at local and global stages of processing.

  2. Employment Pattern, Skills and Training Issues among Informal Sector Workers in Mumbai Metropolitan Region

    Directory of Open Access Journals (Sweden)

    Sanjay RODE

    2015-06-01

    Full Text Available An informal sector in any economy provides different kinds of employment opportunities to people. In Mumbai Metropolitan Region, the female are more involved in regular jobs as compare to the causal and self-employed workers. The secondary and college studied male and female are found more in regular jobs. The high school studied male and illiterate female are working on causal jobs. The causal jobs do not require more education and skills. In self-employed category, the secondary school studied male and high school studied female are found more. The monthly income of workers involved in regular jobs is much higher than the causal and self-employed workers. The moderate malnourished females are found more as compare to the male in causal and self-employed category. The multi nominal logit regression model shows that the causal workers have positive correlation with illiterate male but it is negatively co-related with high school studied male, illiterate and secondary studied female. The monthly income, source of water, refrigerator and condom use is negatively co-related with causal workers as compare to regular workers. The self-employed workers have negative co-relation with monthly wage, source of water and watch cinema regularly as compare to the regular workers. Therefore government must provide infrastructural facilities in all slums of region. The infrastructural facilities such as water supply, electricity, sewage and solid waste collection must be provided in all slums of region. Causal workers must be provided the vocational training to start their own business. Commercial and co-operative banks must provide loans to poor people of slums. Females must be encouraged to take loan and start small business. Government must provide low cost housing to causal and self-employed workers in region. Such policies will certainly improve standard of living of informal sector workers in region.

  3. Residuals of autoregressive model providing additional information for feature extraction of pattern recognition-based myoelectric control.

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

    2015-01-01

    Myoelectric control based on pattern recognition has been studied for several decades. Autoregressive (AR) features are one of the mostly used feature extraction methods among myoelectric control studies. Almost all previous studies only used the AR coefficients without the residuals of AR model for classification. However, the residuals of AR model contain important amplitude information of the electromyography (EMG) signals. In this study, we added the residuals to the AR features (AR+re) and compared its performance with the classical sixth-order AR coefficients. We tested six unilateral transradial amputees and eight able-bodied subjects for eleven hand and wrist motions. The classification accuracy (CA) of the intact side for amputee subjects and the right hand for able-bodied subjects showed that the CA of AR+re features was slightly but significantly higher than that of classical AR features (p = 0.009), which meant that residuals could provide additional information to classical AR features for classification. Interestingly, the CA of the affected side for amputee subjects showed that there was no significant difference between the CA of AR+re features and classical AR features (p > 0.05). We attributed this to the fact that the amputee subjects could not use their affected side to produce consistent EMG patterns as their intact side or the dominant hand of the able-bodied subjects. Since the residuals were already available when the AR coefficients were computed, the results of this study suggested adding the residuals to classical AR features to potentially improve the performance of pattern recognition-based myoelectric control.

  4. Modelling Spatial Patterns and Drivers of Wildfires in Honduras Using Remote Sensing and Geographic Information Systems

    Science.gov (United States)

    Valdez Vasquez, M. C.; Chen, C. F.; Chiang, S. H.

    2016-12-01

    Forests in Honduras are one of the most important resources as they provide a wide range of environmental, economic, and social benefits. However, they are endangered as a result of the relentless occurrence of wildfires during the dry season. Despite the knowledge acquired by the population concerning the effects of wildfires, the frequency is increasing, a pattern attributable to the numerous ignition sources linked to human activity. The purpose of this study is to integrate the wildfire occurrences throughout the 2010-2015 period with a series of anthropogenic and non-anthropogenic variables using the random forest algorithm (RF). We use a series of variables that represent the anthropogenic activity, the flammability of vegetation, climatic conditions, and topography. To represent the anthropogenic activity, we included the continuous distances to rivers, roads, and settlements. To characterize the vegetation flammability, we used the normalized difference vegetation index (NDVI) and the normalized multi-band drought index (NMDI) acquired from MODIS surface reflectance data. Additionally, we included the topographical variables elevation, slope, and solar radiation derived from the ASTER global digital elevation model (GDEM V2). To represent the climatic conditions, we employed the land surface temperature (LST) product from the MODIS sensor and the WorldClim precipitation data. We analyzed the explanatory variables through native RF variable importance analysis and jackknife test, and the results revealed that the dry fuel conditions and low precipitation combined with the proximity to non-paved roads were the major drivers of wildfires. Furthermore, we predicted the areas with highest wildfire susceptibility, which are located mainly in the central and eastern regions of the country, within coniferous and mixed forests. Results acquired were validated using the area under the receiver operating characteristic (ROC) curve and the point biserial correlation

  5. Patterns and determinants of breastfeeding and complementary feeding practices in urban informal settlements, Nairobi Kenya.

    Science.gov (United States)

    Kimani-Murage, Elizabeth W; Madise, Nyovani J; Fotso, Jean-Christophe; Kyobutungi, Catherine; Mutua, Martin K; Gitau, Tabither M; Yatich, Nelly

    2011-05-26

    The World Health Organisation (WHO) recommends exclusive breastfeeding during the first six months of life for optimal growth, development and health. Breastfeeding should continue up to two years or more and nutritionally adequate, safe, and appropriately-fed complementary foods should be introduced at the age of six months to meet the evolving needs of the growing infant. Little evidence exists on breastfeeding and infant feeding practices in urban slums in sub-Saharan Africa. Our aim was to assess breastfeeding and infant feeding practices in Nairobi slums with reference to WHO recommendations. Data from a longitudinal study conducted in two Nairobi slums are used. The study used information on the first year of life of 4299 children born between September 2006 and January 2010. All women who gave birth during this period were interviewed on breastfeeding and complementary feeding practices at recruitment and this information was updated twice, at four-monthly intervals. Cox proportional hazard analysis was used to determine factors associated with cessation of breastfeeding in infancy and early introduction of complementary foods. There was universal breastfeeding with almost all children (99%) having ever been breastfed. However, more than a third (37%) were not breastfed in the first hour following delivery, and 40% were given something to drink other than the mothers' breast milk within 3 days after delivery. About 85% of infants were still breastfeeding by the end of the 11th month. Exclusive breastfeeding for the first six months was rare as only about 2% of infants were exclusively breastfed for six months. Factors associated with sub-optimal infant breastfeeding and feeding practices in these settings include child's sex; perceived size at birth; mother's marital status, ethnicity; education level; family planning (pregnancy desirability); health seeking behaviour (place of delivery) and; neighbourhood (slum of residence). The study indicates poor

  6. Temporal Patterns of Happiness and Information in a Global Social Network: Hedonometrics and Twitter

    Science.gov (United States)

    Dodds, Peter Sheridan; Harris, Kameron Decker; Kloumann, Isabel M.; Bliss, Catherine A.; Danforth, Christopher M.

    2011-01-01

    Individual happiness is a fundamental societal metric. Normally measured through self-report, happiness has often been indirectly characterized and overshadowed by more readily quantifiable economic indicators such as gross domestic product. Here, we examine expressions made on the online, global microblog and social networking service Twitter, uncovering and explaining temporal variations in happiness and information levels over timescales ranging from hours to years. Our data set comprises over 46 billion words contained in nearly 4.6 billion expressions posted over a 33 month span by over 63 million unique users. In measuring happiness, we construct a tunable, real-time, remote-sensing, and non-invasive, text-based hedonometer. In building our metric, made available with this paper, we conducted a survey to obtain happiness evaluations of over 10,000 individual words, representing a tenfold size improvement over similar existing word sets. Rather than being ad hoc, our word list is chosen solely by frequency of usage, and we show how a highly robust and tunable metric can be constructed and defended. PMID:22163266

  7. Investigation of Acupuncture Sensation Patterns under Sensory Deprivation Using a Geographic Information System

    Directory of Open Access Journals (Sweden)

    Florian Beissner

    2012-01-01

    Full Text Available The study of acupuncture-related sensations, like deqi and propagated sensations along channels (PSCs, has a long tradition in acupuncture basic research. The phenomenon itself, however, remains poorly understood. To study the connection between PSC and classical meridians, we applied a geographic information system (GIS to analyze sketches of acupuncture sensations from healthy volunteers after laser acupuncture. As PSC can be subtle, we aimed at reducing the confounding impact of external stimuli by carrying out the experiment in a floatation tank under restricted environmental stimulation. 82.4% of the subjects experienced PSC, that is, they had line-like or 2-dimensional sensations, although there were some doubts that these were related to the laser stimulation. Line-like sensations on the same limb were averaged to calculate sensation mean courses, which were then compared to classical meridians by measuring the mean distance between the two. Distances ranged from 0.83 cm in the case of the heart (HT and spleen (SP meridian to 6.27 cm in the case of the kidney (KI meridian. Furthermore, PSC was observed to “jump” between adjacent meridians. In summary, GIS has proven to be a valuable tool to study PSC, and our results suggest a close connection between PSC and classical meridians.

  8. The Impact of PMIS Training: Patterns of Benefit Realization in Project Management Information Systems Training

    Directory of Open Access Journals (Sweden)

    Andrew McCarty

    2017-01-01

    Full Text Available The benefits of project, program, and portfolio management software toolsets can be enhanced through training. Little is known about the realization of positive, beneficial outcomes and Project Management Information System (PMIS training. This research seeks to improve understanding of project management software toolset training practices and outcomes. This study examines the prevalence, effectiveness, and impact-per-hour efficiency of training in real-world organizations. We further explore relationships between individual and organizational characteristics and training outcomes. Formulae for estimating training costs are derived using regression modeling. Surveys were collected from 1,021 active professionals and analyzed using quantitative methods. Research participants were practitioners recruited by eight different companies, industry groups, and professional organizations within the PMIS community. The findings of this research indicate significant differences in utilization, efficacy, and efficiency of PMIS training in practice. The outcomes and methodologies of this study are being incorporated into ongoing research that focuses on improving PMIS training delivery, evaluation, and planning. The outcomes of this research may result in more effective, efficient, and economical PMIS training that is better tailored to the unique needs of each organization.

  9. Investigation of Acupuncture Sensation Patterns under Sensory Deprivation Using a Geographic Information System.

    Science.gov (United States)

    Beissner, Florian; Marzolff, Irene

    2012-01-01

    The study of acupuncture-related sensations, like deqi and propagated sensations along channels (PSCs), has a long tradition in acupuncture basic research. The phenomenon itself, however, remains poorly understood. To study the connection between PSC and classical meridians, we applied a geographic information system (GIS) to analyze sketches of acupuncture sensations from healthy volunteers after laser acupuncture. As PSC can be subtle, we aimed at reducing the confounding impact of external stimuli by carrying out the experiment in a floatation tank under restricted environmental stimulation. 82.4% of the subjects experienced PSC, that is, they had line-like or 2-dimensional sensations, although there were some doubts that these were related to the laser stimulation. Line-like sensations on the same limb were averaged to calculate sensation mean courses, which were then compared to classical meridians by measuring the mean distance between the two. Distances ranged from 0.83 cm in the case of the heart (HT) and spleen (SP) meridian to 6.27 cm in the case of the kidney (KI) meridian. Furthermore, PSC was observed to "jump" between adjacent meridians. In summary, GIS has proven to be a valuable tool to study PSC, and our results suggest a close connection between PSC and classical meridians.

  10. Patronen van kommunikatie en hun organisatorisch verband bij de landbouwvoorlichting in Suriname 1967-1969 [Patterns of communication in agricultural information in Surinam 1967-1969

    NARCIS (Netherlands)

    Kalshoven, G.

    1969-01-01

    The organization of communication patterns in agricultural information service / assistants were asked about the farmers in their districts / contacts with the farmers / the extent to which advice is accepted and implemented / progressive versus traditional farmers / the influence of politics ( patr

  11. Library usage patterns in the electronic information environment. Electronic journals, Use studies, Libraries, Medical libraries

    Directory of Open Access Journals (Sweden)

    B. Franklin

    2004-01-01

    Full Text Available This paper examines the methodology and results from Web-based surveys of more than 15,000 networked electronic services users in the United States between July 1998 and June 2003 at four academic health sciences libraries and two large main campus libraries serving a variety of disciplines. A statistically valid methodology for administering simultaneous Web-based and print-based surveys using the random moments sampling technique is discussed and implemented. Results from the Web-based surveys showed that at the four academic health sciences libraries, there were approximately four remote networked electronic services users for each in-house user. This ratio was even higher for faculty, staff, and research fellows at the academic health sciences libraries, where more than five remote users for each in-house user were recorded. At the two main libraries, there were approximately 1.3 remote users for each in-house user of electronic information. Sponsored research (grant funded research accounted for approximately 32% of the networked electronic services activity at the health sciences libraries and 16% at the main campus libraries. Sponsored researchers at the health sciences libraries appeared to use networked electronic services most intensively from on-campus, but not from in the library. The purpose of use for networked electronic resources by patrons within the library is different from the purpose of use of those resources by patrons using the resources remotely. The implications of these results on how librarians reach decisions about networked electronic resources and services are discussed.

  12. Accessibility patterns and community integration among previously homeless adults: a Geographic Information Systems (GIS) approach.

    Science.gov (United States)

    Chan, Dara V; Gopal, Sucharita; Helfrich, Christine A

    2014-11-01

    Although a desired rehabilitation goal, research continues to document that community integration significantly lags behind housing stability success rates for people of a variety of ages who used to be homeless. While accessibility to resources is an environmental factor that may promote or impede integration activity, there has been little empirical investigation into the impact of proximity of community features on resource use and integration. Using a Geographic Information Systems (GIS) approach, the current study examines how accessibility or proximity to community features in Boston, United States related to the types of locations used and the size of an individual's "activity space," or spatial presence in the community. Significant findings include an inverse relationship between activity space size and proximity to the number and type of community features in one's immediate area. Specifically, larger activity spaces were associated with neighborhoods with less community features, and smaller activity spaces corresponded with greater availability of resources within one's immediate area. Activity space size also varied, however, based on proximity to different types of resources, namely transportation and health care. Greater community function, or the ability to navigate and use community resources, was associated with better accessibility and feeling part of the community. Finally, proximity to a greater number of individual identified preferred community features was associated with better social integration. The current study suggests the ongoing challenges of successful integration may vary not just based on accessibility to, but relative importance of, specific community features and affinity with one's surroundings. Community integration researchers and housing providers may need to attend to the meaning attached to resources, not just presence or use in the community.

  13. Gender-Specific Determinants and Patterns of Online Health Information Seeking: Results From a Representative German Health Survey

    Science.gov (United States)

    Baumann, Eva; Czerwinski, Fabian

    2017-01-01

    Background Online health information-seeking behavior (OHISB) is currently a widespread and common behavior that has been described as an important prerequisite of empowerment and health literacy. Although demographic factors such as socioeconomic status (SES), age, and gender have been identified as important determinants of OHISB, research is limited regarding the gender-specific motivational determinants of OHISB and differences between women and men in the use of online resources for health information purposes. Objective The aim of this study was to identify gender-specific determinants and patterns of OHISB by analyzing data from a representative German sample of adults (N=1728) with special attention to access and frequency of use as well as topics and sources of OHISB. Methods We employed a 2-step analysis, that is, after exploring differences between users and nonusers of online health information using logistic regression models, we highlighted gender-specific determinants of the frequency of OHISB by applying zero-truncated negative binomial models. Results Age (odds ratio, OR for females=0.97, 95% CI 0.96-0.99) and degree of satisfaction with one’s general practitioner (GP) (OR for males=0.73, 95% CI 0.57-0.92) were gender-specific determinants of access to OHISB. Regarding the frequency of OHISB, daily Internet use (incidence rate ratio, IRR=1.67, 95% CI 1.19-2.33) and a strong interest in health topics (IRR=1.45, 95% CI 1.19-1.77) were revealed to be more important predictors than SES (IRR for high SES=1.25, 95% CI 0.91-1.73). Conclusions Users indicate that the Internet seems to be capable of providing a valuable source of informational support and patient empowerment. Increasing the potential value of the Internet as a source for health literacy and patient empowerment requires need-oriented and gender-specific health communication efforts, media, and information strategies. PMID:28377367

  14. Focusing of high-wave-vector magnons

    Science.gov (United States)

    Bible, J. J.; Camley, R. E.

    2017-06-01

    The focusing of spin waves in magnetic materials has a number of important advantages for directing energy and thus information. In contrast to earlier works, we theoretically calculate the focusing of short-wavelength spin waves. We show that strong focusing of large wave-vector spin waves naturally occurs about halfway out in the Brillouin zone with no need for a magnetocrystalline anisotropy, dipolar effects, or an external magnetic field. The fact that the wavelength is on the order of the lattice constant leads to a form of lattice-induced anisotropy in the wave propagation. We also explore the tunability that is achieved by the application of both an external field and a uniaxial anisotropy. In this case there is a rotation of the focusing pattern. The rotation angle can be changed by varying the field strength, demonstrating tunability.

  15. Using High Performance Computing to Examine the Processes of Neurogenesis Underlying Pattern Separation and Completion of Episodic Information.

    Energy Technology Data Exchange (ETDEWEB)

    Aimone, James Bradley; Bernard, Michael Lewis; Vineyard, Craig Michael; Verzi, Stephen Joseph.

    2014-10-01

    Adult neurogenesis in the hippocampus region of the brain is a neurobiological process that is believed to contribute to the brain's advanced abilities in complex pattern recognition and cognition. Here, we describe how realistic scale simulations of the neurogenesis process can offer both a unique perspective on the biological relevance of this process and confer computational insights that are suggestive of novel machine learning techniques. First, supercomputer based scaling studies of the neurogenesis process demonstrate how a small fraction of adult-born neurons have a uniquely larger impact in biologically realistic scaled networks. Second, we describe a novel technical approach by which the information content of ensembles of neurons can be estimated. Finally, we illustrate several examples of broader algorithmic impact of neurogenesis, including both extending existing machine learning approaches and novel approaches for intelligent sensing.

  16. Wave spectra partitioning and long term statistical distribution

    Science.gov (United States)

    Portilla-Yandún, Jesús; Cavaleri, Luigi; Van Vledder, Gerbrant Ph.

    2015-12-01

    A new method is presented for a physically based statistical description of wind wave climatology. The method applies spectral partitioning to identify individual wave systems (partitions) in time series of 2D-wave spectra, followed by computing the probability of occurrence of their (peak) position in frequency-direction space. This distribution can be considered as a spectral density function to which another round of partitioning is applied to obtain spectral domains, each representing a typical wave system or population in a statistical sense. This two-step partitioning procedure allows identifying aggregate wave systems without the need to discuss specific characteristics as wind sea and swell systems. We suggest that each of these aggregate wave systems (populations) is linked to a specific generation pattern opening the way to dedicated analyses. Each population (of partitions) can be subjected to further analyses to add dimension carrying information based on integrated wave parameters of each partition, such as significant wave height, wave age, mean wave period and direction, among others. The new method is illustrated by analysing model spectra from a numerical wave prediction model and measured spectra from a directional wave buoy located in the Southern North Sea. It is shown that these two sources of information yield consistent results. Examples are given of computing the statistical distribution of significant wave height, spectral energy distribution and the spatial variation of wind wave characteristics along a north-south transect in the North Sea. Wind or wave age information can be included as an extra attribute of the members of a population to label them as wind sea or swell systems. Finally, suggestions are given for further applications of this new method.

  17. Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells

    CERN Document Server

    Amor, Rumelo; Amos, William Bradshaw; McConnell, Gail

    2014-01-01

    Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report that the relative intensities in each plane of excitation depend on the Stokes shift of the fluorochrome. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ~90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.

  18. Googling in anatomy education: Can google trends inform educators of national online search patterns of anatomical syllabi?

    Science.gov (United States)

    Phelan, Nigel; Davy, Shane; O'Keeffe, Gerard W; Barry, Denis S

    2017-03-01

    The role of e-learning platforms in anatomy education continues to expand as self-directed learning is promoted in higher education. Although a wide range of e-learning resources are available, determining student use of non-academic internet resources requires novel approaches. One such approach that may be useful is the Google Trends(©) web application. To determine the feasibility of Google Trends to gain insights into anatomy-related online searches, Google Trends data from the United States from January 2010 to December 2015 were analyzed. Data collected were based on the recurrence of keywords related to head and neck anatomy generated from the American Association of Clinical Anatomists and the Anatomical Society suggested anatomy syllabi. Relative search volume (RSV) data were analyzed for seasonal periodicity and their overall temporal trends. Following exclusions due to insufficient search volume data, 29 out of 36 search terms were analyzed. Significant seasonal patterns occurred in 23 search terms. Thirty-nine seasonal peaks were identified, mainly in October and April, coinciding with teaching periods in anatomy curricula. A positive correlation of RSV with time over the 6-year study period occurred in 25 out of 29 search terms. These data demonstrate how Google Trends may offer insights into the nature and timing of online search patterns of anatomical syllabi and may potentially inform the development and timing of targeted online supports to ensure that students of anatomy have the opportunity to engage with online content that is both accurate and fit for purpose. Anat Sci Educ 10: 152-159. © 2016 American Association of Anatomists.

  19. Séparation des ondes P et S à l'aide de la matrice spectrale avec informations à priori The Separation of P and S Waves Using the Spectral Matrix with a Priori Information

    Directory of Open Access Journals (Sweden)

    Mari J. L.

    2006-11-01

    Full Text Available Classiquement, la technique de filtrage utilisant la matrice spectrale proposée par Mermoz ne permet une séparation automatique des ondes au sens des indicatrices sismiques que dans certains cas particuliers, à savoir lorsque les ondes à séparer sont naturellement alignées sur les vecteurs propres de la matrice spectrale. Dans les autres cas, nous montrons que l'introduction d'information a priori sur la vitesse apparente de quelques ondes et une limitation de la durée temporelle de ces dernières permettent d'estimer leurs vecteurs d'ondes. L'utilisation de ces vecteurs et une technique de projection au sens des moindres carrés conduit à une extraction optimale de ces ondes, sans dégrader les autres ondes. La technique de filtrage proposée a été appliquée sur des données sismiques de type PSV (profil sismique vertical déporté. Le PSV a été enregistré dans un puits entre les cotes 1050 m et 1755 m; la source est déportée de 654 m par rapport à la tête de puits. L'outil utilisé est un géophone de puits à trois composantes. Le puits traverse une structure géologique complexe. Le traitement réalisé a mis en évidence des réflexions sismiques d'ondes de compression et de cisaillement, associées à des marqueurs fortement pentés (10 à 25°. Après estimation des champs de vitesse et des pendages à l'aide d'abaques, la migration en profondeur des horizons temps pointés a permis d'obtenir un modèle structural faillé. Detailed structural analysis can be achieved by using 3-component vertical seismic profiling method which gives structural information at several hundred meters from the wellhead. The use of an offset VSP on the Auzance structure has led to obtain a structural model composed by faulted dipping reflectors. This is due to the robust nature of the wave separation method which is based on the spectral matrix and uses an a priori information. This method preserves the true amplitude and the local apparent

  20. Patterns of genetic structure and evidence of gene flow among Tunisian Citrus species based on informative nSSR markers.

    Science.gov (United States)

    Ben Romdhane, Meriam; Riahi, Leila; Selmi, Ayet; Zoghlami, Nejia

    2016-01-01

    This study investigates the extent of genetic diversity, phylogenetic relationships and the amount of gene flow among Tunisian Citrus species based on a set of 15 informative nuclear SSR molecular markers. Genotyping data highlighted an allelic richness among Tunisian Citrus species and has allowed the detection of 168 alleles among them 104.19 were effective. The partition of the total genetic diversity (HT=0.832) showed that the highest amount of variation within the Citrus species is HS=0.550, while the relative amount of the between-species genetic diversity GST does not exceed 0.338. This pattern of genetic structure was supported by low-to-moderate FST pairwise values and the presence of a gene flow (Nm) among the eight Citrus species. The lowest genetic differentiation was revealed between the species C. sinensis and C. insitorum (FST=0.111, Nm=1.99), while the highest genetic differentiation was recorded between the species C. aurantifolia and C. paradisi (FST=0.367, Nm=0.43). The established Neighbor Joining analysis showed that all genotypes were widely discriminated and clearly pooled according to their species of origin, with minor exceptions. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  1. Rain waves-wind waves interaction application to scatterometry

    Science.gov (United States)

    Kharif, C.; Giovanangeli, J. P.; Bliven, L.

    1989-01-01

    Modulation of a rain wave pattern by longer waves has been studied. An analytical model taking into account capillarity effects and obliquity of short waves has been developed. Modulation rates in wave number and amplitude have been computed. Experiments were carried out in a wave tank. First results agree with theoretical models, but higher values of modulation rates are measured. These results could be taken into account for understanding the radar response from the sea surface during rain.

  2. Robust Wave Resource Estimation

    DEFF Research Database (Denmark)

    Lavelle, John; Kofoed, Jens Peter

    2013-01-01

    An assessment of the wave energy resource at the location of the Danish Wave Energy test Centre (DanWEC) is presented in this paper. The Wave Energy Converter (WEC) test centre is located at Hanstholm in the of North West Denmark. Information about the long term wave statistics of the resource...... is necessary for WEC developers, both to optimise the WEC for the site, and to estimate its average yearly power production using a power matrix. The wave height and wave period sea states parameters are commonly characterized with a bivariate histogram. This paper presents bivariate histograms and kernel...... density estimates of the PDF as a function both of Hm0 and Tp, and Hm0 and T0;2, together with the mean wave power per unit crest length, Pw, as a function of Hm0 and T0;2. The wave elevation parameters, from which the wave parameters are calculated, are filtered to correct or remove spurious data...

  3. Multisource classification and pattern recognition methods for polar geospatial information mining using WorldView-2 data

    Science.gov (United States)

    Khopkar, Parag S.; Jawak, Shridhar D.; Luis, Alvarinho J.

    2016-04-01

    Current research study emphasizes the importance of advanced digital image processing methods in order to delineate between various LULC features. In the case of the Antarctica, the present LC (snow/ice, landmass, water, vegetation etc.) and the present LU (research stations of various nations) needs to be mapped accurately for the hassle free routine activities. Geo-location has become the most important part of geosciences studies. In this paper we have tried to locate three most important features (snow/ice, landmass, and water) and also have extracted the extent of the same using the multisource classification (image fusion/pansharpening) and pattern recognition (supervised/unsupervised methods, index ratio methods). Innovation in developing spectral index ratios has led us to come up with an unique ratio named Normalized Difference Landmass Index (NDLI) which performed better (Avg. Bias: 51.99m) than other ratios such as Normalized Difference Snow/Ice Index (NDSII) (Avg. Bias: -1572.11m) and Normalized Difference Water Index (NDWI) (Avg. Bias: 1886.60m). The practiced trial and error methodology quantifies the productivity of not only the classification methods over one other but also that of the fusion methods. In present study, classifiers used (Mahalanobis and Winner Takes All) performed better (Avg. Bias: 122.16 m) than spectral index ratios (Avg. Bias: 620.16 m). The study also revealed that newly introduced bands in WorldView-2, band 1 (Coastal Blue), 4 (Yellow), 6 (Red-edge) and 8 (Near Infrared-2) along with traditional bands have the capacity to mine the polar geospatial information with utmost accuracy and efficiency.

  4. Topography-induced focusing of random waves

    NARCIS (Netherlands)

    Smit, P.B.; Janssen, T.T.; Herbers, T.H.C.

    2012-01-01

    Refraction of narrow-band surface waves in coastal areas can result in wave-focal zones where due to interference, wave statistics vary rapidly and on similar length scales as those of individual waves. However such interference patterns, or wave coherence, are not accounted for in conventional stoc

  5. Computer Attitude, and the Impact of Personal Characteristics and Information and Communication Technology Adoption Patterns on Performance of Teaching Faculty in Higher Education in Ghana, West Africa

    Science.gov (United States)

    Larbi-Apau, Josephine A.

    2011-01-01

    This study examined computer attitude, and the impact of personal characteristics and ICT adoption patterns on performance of multidisciplinary teaching faculty in three public universities in Ghana. A cross-sectional research of mixed methods was applied in collecting data and information. Quantitative data from 164 respondents were analyzed…

  6. Differences in EEG delta frequency characteristics and patterns in slow-wave sleep between dementia patients and controls: a pilot study.

    Science.gov (United States)

    Bonanni, Enrica; Di Coscio, Elisa; Maestri, Michelangelo; Carnicelli, Luca; Tsekou, Hara; Economou, Nicholas Tiberio; Paparrigopoulos, Thomas; Bonakis, Anastasios; Papageorgiou, Sokratis G; Vassilopoulos, Dimitris; Soldatos, Constantin R; Murri, Luigi; Ktonas, Periklis Y

    2012-02-01

    To evaluate the modifications of EEG activity during slow-wave sleep in patients with dementia compared with healthy elderly subjects, using spectral analysis and period-amplitude analysis. Five patients with dementia and 5 elderly control subjects underwent night polysomnographic recordings. For each of the first three nonrapid eye movement-rapid eye movement sleep cycles, a well-defined slow-wave sleep portion was chosen. The delta frequency band (0.4-3.6 Hz) in these portions was analyzed with both spectral analysis and period-amplitude analysis. Spectral analysis showed an increase in the delta band power in the dementia group, with a decrease across the night observed only in the control group. For the dementia group, period-amplitude analysis showed a decrease in well-defined delta waves of frequency lower than 1.6 Hz and an increase in such waves of frequency higher than 2 Hz, in incidence and amplitude. Our study showed (1) a loss of the dynamics of delta band power across the night sleep, in dementia, and (2) a different distribution of delta waves during slow-wave sleep in dementia compared with control subjects. This kind of computer-based analysis can highlight the presence of a pathologic delta activity during slow-wave sleep in dementia and may support the hypothesis of a dynamic interaction between sleep alteration and cognitive decline.

  7. Specialization Patterns

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh; Lawall, Julia Laetitia; Consel, Charles

    2000-01-01

    Design patterns offer many advantages for software development, but can introduce inefficiency into the final program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose that these concepts...... are complementary. Program specialization can optimize programs written using design patterns, and design patterns provide information about the program structure that can guide specialization. Concretely, we propose specialization patterns, which describe how to apply program specialization to optimize uses...... of design patterns. In this paper, we analyze the specialization opportunities provided by specific uses of design patterns. Based on the analysis of each design pattern, we define the associated specialization pattern. These specialization opportunities can be declared using the specialization classes...

  8. Spatial Patterns of Ischemic Heart Disease in Shenzhen, China: A Bayesian Multi-Disease Modelling Approach to Inform Health Planning Policies.

    Science.gov (United States)

    Du, Qingyun; Zhang, Mingxiao; Li, Yayan; Luan, Hui; Liang, Shi; Ren, Fu

    2016-04-20

    Incorporating the information of hypertension, this paper applies Bayesian multi-disease analysis to model the spatial patterns of Ischemic Heart Disease (IHD) risks. Patterns of harmful alcohol intake (HAI) and overweight/obesity are also modelled as they are common risk factors contributing to both IHD and hypertension. The hospitalization data of IHD and hypertension in 2012 were analyzed with three Bayesian multi-disease models at the sub-district level of Shenzhen. Results revealed that the IHD high-risk cluster shifted slightly north-eastward compared with the IHD Standardized Hospitalization Ratio (SHR). Spatial variations of overweight/obesity and HAI were found to contribute most to the IHD patterns. Identified patterns of IHD risk would benefit IHD integrated prevention. Spatial patterns of overweight/obesity and HAI could supplement the current disease surveillance system by providing information about small-area level risk factors, and thus benefit integrated prevention of related chronic diseases. Middle southern Shenzhen, where high risk of IHD, overweight/obesity, and HAI are present, should be prioritized for interventions, including alcohol control, innovative healthy diet toolkit distribution, insurance system revision, and community-based chronic disease intervention. Related health resource planning is also suggested to focus on these areas first.

  9. Spatial Patterns of Ischemic Heart Disease in Shenzhen, China: A Bayesian Multi-Disease Modelling Approach to Inform Health Planning Policies

    Directory of Open Access Journals (Sweden)

    Qingyun Du

    2016-04-01

    Full Text Available Incorporating the information of hypertension, this paper applies Bayesian multi-disease analysis to model the spatial patterns of Ischemic Heart Disease (IHD risks. Patterns of harmful alcohol intake (HAI and overweight/obesity are also modelled as they are common risk factors contributing to both IHD and hypertension. The hospitalization data of IHD and hypertension in 2012 were analyzed with three Bayesian multi-disease models at the sub-district level of Shenzhen. Results revealed that the IHD high-risk cluster shifted slightly north-eastward compared with the IHD Standardized Hospitalization Ratio (SHR. Spatial variations of overweight/obesity and HAI were found to contribute most to the IHD patterns. Identified patterns of IHD risk would benefit IHD integrated prevention. Spatial patterns of overweight/obesity and HAI could supplement the current disease surveillance system by providing information about small-area level risk factors, and thus benefit integrated prevention of related chronic diseases. Middle southern Shenzhen, where high risk of IHD, overweight/obesity, and HAI are present, should be prioritized for interventions, including alcohol control, innovative healthy diet toolkit distribution, insurance system revision, and community-based chronic disease intervention. Related health resource planning is also suggested to focus on these areas first.

  10. Spatial Patterns of Ischemic Heart Disease in Shenzhen, China: A Bayesian Multi-Disease Modelling Approach to Inform Health Planning Policies

    Science.gov (United States)

    Du, Qingyun; Zhang, Mingxiao; Li, Yayan; Luan, Hui; Liang, Shi; Ren, Fu

    2016-01-01

    Incorporating the information of hypertension, this paper applies Bayesian multi-disease analysis to model the spatial patterns of Ischemic Heart Disease (IHD) risks. Patterns of harmful alcohol intake (HAI) and overweight/obesity are also modelled as they are common risk factors contributing to both IHD and hypertension. The hospitalization data of IHD and hypertension in 2012 were analyzed with three Bayesian multi-disease models at the sub-district level of Shenzhen. Results revealed that the IHD high-risk cluster shifted slightly north-eastward compared with the IHD Standardized Hospitalization Ratio (SHR). Spatial variations of overweight/obesity and HAI were found to contribute most to the IHD patterns. Identified patterns of IHD risk would benefit IHD integrated prevention. Spatial patterns of overweight/obesity and HAI could supplement the current disease surveillance system by providing information about small-area level risk factors, and thus benefit integrated prevention of related chronic diseases. Middle southern Shenzhen, where high risk of IHD, overweight/obesity, and HAI are present, should be prioritized for interventions, including alcohol control, innovative healthy diet toolkit distribution, insurance system revision, and community-based chronic disease intervention. Related health resource planning is also suggested to focus on these areas first. PMID:27104551

  11. Visual motion discrimination by propagating patterns in primate cerebral cortex.

    Science.gov (United States)

    Townsend, Rory; Solomon, Selina S; Martin, Paul R; Solomon, Samuel G; Gong, Pulin

    2017-09-14

    Visual stimuli can evoke waves of neural activity that propagate across the surface of visual cortical areas. The relevance of these waves for visual processing is unknown. Here we measured the phase and amplitude of local field potentials (LFPs) in electrode array recordings from motion-processing medial temporal area (MT) of anesthetized male marmosets. Animals viewed grating or dot-field stimuli drifting in different directions. We found that on individual trials, the direction of LFP wave propagation is sensitive to the direction of stimulus motion. Propagating LFP patterns are also detectable in trial-averaged activity, but the trial-averaged patterns exhibit different dynamics and behaviors to those in single trials and are similar across motion directions. We show that this difference arises because stimulus-sensitive propagating patterns are present in the phase of single-trial oscillations, whereas the trial-averaged signal is dominated by additive amplitude effects. Our results demonstrate that propagating LFP patterns can represent sensory inputs, at timescales relevant to visually-guided behaviors, and raise the possibility that propagating activity patterns serve neural information processing in area MT and other cortical areas.SIGNIFICANCE STATEMENTPropagating wave patterns are widely observed in the cortex, but their functional relevance remains unknown. We show here that visual stimuli generate propagating wave patterns in local field potentials (LFPs) in a movement-sensitive area of the primate cortex, and that the propagation direction of these patterns is sensitive to stimulus motion direction. We also show that averaging LFP signals across multiple stimulus presentations (trial-averaging) yields propagating patterns which capture different dynamic properties of the LFP response and show negligible direction sensitivity. Our results demonstrate that sensory stimuli can reliably modulate propagating wave patterns in the cortex. The relevant

  12. Methods, systems, and apparatus for storage, transfer and/or control of information via matter wave dynamics

    Science.gov (United States)

    Vestergaard Hau, Lene (Inventor)

    2012-01-01

    Methods, systems and apparatus for generating atomic traps, and for storing, controlling and transferring information between first and second spatially separated phase-coherent objects, or using a single phase-coherent object. For plural objects, both phase-coherent objects have a macroscopic occupation of a particular quantum state by identical bosons or identical BCS-paired fermions. The information may be optical information, and the phase-coherent object(s) may be Bose-Einstein condensates, superfluids, or superconductors. The information is stored in the first phase-coherent object at a first storage time and recovered from the second phase-coherent object, or the same first phase-coherent object, at a second revival time. In one example, an integrated silicon wafer-based optical buffer includes an electrolytic atom source to provide the phase-coherent object(s), a nanoscale atomic trap for the phase-coherent object(s), and semiconductor-based optical sources to cool the phase-coherent object(s) and provide coupling fields for storage and transfer of optical information.

  13. Formal and Informal Learning and First-Year Psychology Students' Development of Scientific Thinking: A Two-Wave Panel Study.

    Science.gov (United States)

    Soyyılmaz, Demet; Griffin, Laura M; Martín, Miguel H; Kucharský, Šimon; Peycheva, Ekaterina D; Vaupotič, Nina; Edelsbrunner, Peter A

    2017-01-01

    Scientific thinking is a predicate for scientific inquiry, and thus important to develop early in psychology students as potential future researchers. The present research is aimed at fathoming the contributions of formal and informal learning experiences to psychology students' development of scientific thinking during their 1st-year of study. We hypothesize that informal experiences are relevant beyond formal experiences. First-year psychology student cohorts from various European countries will be assessed at the beginning and again at the end of the second semester. Assessments of scientific thinking will include scientific reasoning skills, the understanding of basic statistics concepts, and epistemic cognition. Formal learning experiences will include engagement in academic activities which are guided by university authorities. Informal learning experiences will include non-compulsory, self-guided learning experiences. Formal and informal experiences will be assessed with a newly developed survey. As dispositional predictors, students' need for cognition and self-efficacy in psychological science will be assessed. In a structural equation model, students' learning experiences and personal dispositions will be examined as predictors of their development of scientific thinking. Commonalities and differences in predictive weights across universities will be tested. The project is aimed at contributing information for designing university environments to optimize the development of students' scientific thinking.

  14. Formal and Informal Learning and First-Year Psychology Students’ Development of Scientific Thinking: A Two-Wave Panel Study

    Science.gov (United States)

    Soyyılmaz, Demet; Griffin, Laura M.; Martín, Miguel H.; Kucharský, Šimon; Peycheva, Ekaterina D.; Vaupotič, Nina; Edelsbrunner, Peter A.

    2017-01-01

    Scientific thinking is a predicate for scientific inquiry, and thus important to develop early in psychology students as potential future researchers. The present research is aimed at fathoming the contributions of formal and informal learning experiences to psychology students’ development of scientific thinking during their 1st-year of study. We hypothesize that informal experiences are relevant beyond formal experiences. First-year psychology student cohorts from various European countries will be assessed at the beginning and again at the end of the second semester. Assessments of scientific thinking will include scientific reasoning skills, the understanding of basic statistics concepts, and epistemic cognition. Formal learning experiences will include engagement in academic activities which are guided by university authorities. Informal learning experiences will include non-compulsory, self-guided learning experiences. Formal and informal experiences will be assessed with a newly developed survey. As dispositional predictors, students’ need for cognition and self-efficacy in psychological science will be assessed. In a structural equation model, students’ learning experiences and personal dispositions will be examined as predictors of their development of scientific thinking. Commonalities and differences in predictive weights across universities will be tested. The project is aimed at contributing information for designing university environments to optimize the development of students’ scientific thinking. PMID:28239363

  15. On the atmospheric internal ship waves

    Institute of Scientific and Technical Information of China (English)

    桑建国

    1997-01-01

    The analytical solutions of the atmospheric internal ship waves induced by three-dimensional terrain are obtained by solving the atmospheric wave equation. The solutions show that the waves consist of the untrapped and trapped parts. The patterns of the diverging wave and transverse wave in the untrapped parts are mainly determined by the shape and orientation of the terrain. This kind of wave may transport the wave energy to the upper atmosphere. The patterns of trapped lee waves are decided by the atmospheric conditions such as stratification, mean wind speeds and wind shear.

  16. Development and Validation of the Social Information Processing Application: A Web-Based Measure of Social Information Processing Patterns in Elementary School-Age Boys

    Science.gov (United States)

    Kupersmidt, Janis B.; Stelter, Rebecca; Dodge, Kenneth A.

    2011-01-01

    The purpose of this study was to evaluate the psychometric properties of an audio computer-assisted self-interviewing Web-based software application called the Social Information Processing Application (SIP-AP) that was designed to assess social information processing skills in boys in RD through 5th grades. This study included a racially and…

  17. Utilizing patterns of agricultural information-seeking by farmers to monitor and predict future changes in behavior

    OpenAIRE

    Abbott, E; Mironova, G.

    2013-01-01

    The rate of information seeking about an agricultural innovation can be used to predict the rate of adoption of the innovation. A study over 15 years shows that farmers who increased information seeking about farm computers were more likely to adopt. Those whose information seeking declined were less likely to adopt, and some who had adopted actually discontinued use.

  18. The analysis of longitudinal quality of life measures with informative drop-out : A pattern mixture approach

    NARCIS (Netherlands)

    Post, W.J.; Buijs, C.; Stolk, R.P.; de Vries, E.G.E.; le Cessie, S.

    The analysis of longitudinal health-related quality of life measures (HRQOL) can be seriously hampered due to informative drop-out. Random effects models assume Missing At Random and do not take into account informative drop-out. We therefore aim to correct the bias due to informative drop-out.

  19. Deep Web result pattern extracting based on heuristic information%基于启发式信息的Deep Web结果模式获取方法

    Institute of Scientific and Technical Information of China (English)

    李明; 李秀兰

    2011-01-01

    获取模式信息是深入研究Deep Web数据的必要步骤,针对Deep Web结果模式结构信息的丢失问题,提出了一种基于启发式信息的Deep Web结果模式获取方法.通过解析Deep Web结果页面数据,利用启发式信息为结果页面数据添加正确的属性名,进而得到对应Deep Web的结果模式,并对其进行规范化处理,解决不同数据源结果模式的结构不一致问题.实验验证该方法可以有效地获取Deep Web的结果模式信息.%Extracting schema information is the necessary step in the Deep Web data research, to address the loss problem of Deep Web result schema information, this paper proposed a novel approach Deep Web result pattern extracting based on heuristic information. Through analyzing Deep Web result page data and adding correct attribute names to result pages data by heuristic information, it obtained the corresponding of Deep Web result pattern. Moreover, it solved the structure conflict by standardized treatment. Experimental results show that the method can effectively extract result pattern.

  20. How reproducible is self-reported information on exposure to smoking, drinking, and dietary patterns? Evidence among Brazilian adults in the Pró-Saúde Study

    Directory of Open Access Journals (Sweden)

    Dóra Chor

    Full Text Available CONTEXT: Epidemiological studies of the validity and reliability of self-reported information on important risk factors for non-communicable chronic diseases are scarce in Brazil. OBJECTIVE: We evaluated the test-retest reliability of information overall and stratified by gender, age and education on active and passive smoking, alcohol intake and aspects of dietary habits. TYPE OF STUDY: Test-retest reliability. SETTING: Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. PARTICIPANTS: 192 University employees. PROCEDURES: Self-administered questionnaires were completed on two occasions, two weeks apart. MAIN MEASUREMENTS: Kappa Statistics; Intraclass Correlation Coefficient. RESULTS: Information on smoking status and pack-years smoked had almost perfect levels of agreement, respectively, kappa = 0.97 (95% CI, 0.92-1.00, and intraclass correlation coefficient = 0.93 (CI 95%, 0.89-0.96. Characteristics of alcohol intake yielded substantial levels of agreement (kappa ranging from 0.62 to 0.69. The reproducibility of the information on dietary habits varied from 0.67 to 0.79 (kappa. No clear-cut patterns could be identified comparing information by age or gender. There was a slight tendency towards greater reliability among people with higher levels of education. CONCLUSION: The reproducibility of information on smoking, drinking, and dietary patterns ranged from substantial to excellent, as investigated in the Pró-Saúde Study, a longitudinal investigation recently launched in Rio de Janeiro.

  1. Demand patterns for HIV-tests in general practice: information collected by sentinel networks in 5 European countries.

    NARCIS (Netherlands)

    Casteren, V. van; Leurquin, P.; Bartelds, A.; Gurtner, F.; Massari, V.; Maurice-Tison, S.; Vega, A.T.; Mak, R.

    1993-01-01

    This study describes a 1 year international data collection on the demand pattern for HIV-antibody tests in general practice recorded by 6 sentinel networks in 5 European countries. The purpose of the recording was to evaluate the use of HIV-antibody testing by general practitioners and the demand

  2. A study on scientific collaboration and co-authorship patterns in library and information science studies in Iran between 2005 and 2009

    OpenAIRE

    Siamaki, Saba; Geraei, Ehsan; Zare- Farashbandi, Firoozeh

    2014-01-01

    Background: Scientific collaboration is among the most important subjects in scientometrics, and many studies have investigated this concept to this day. The goal of the current study is investigation of scientific collaboration and co-authorship patterns of researchers in the field of library and information science in Iran between years 2005 and 2009. Materials and Methods: The current study uses scientometrics method. The statistical population consists of 942 documents published in Irania...

  3. Pattern recognition

    CERN Document Server

    Theodoridis, Sergios

    2003-01-01

    Pattern recognition is a scientific discipline that is becoming increasingly important in the age of automation and information handling and retrieval. Patter Recognition, 2e covers the entire spectrum of pattern recognition applications, from image analysis to speech recognition and communications. This book presents cutting-edge material on neural networks, - a set of linked microprocessors that can form associations and uses pattern recognition to ""learn"" -and enhances student motivation by approaching pattern recognition from the designer's point of view. A direct result of more than 10

  4. Information

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    There are unstructured abstracts (no more than 256 words) and structured abstracts (no more than 480). The specific requirements for structured abstracts are as follows:An informative, structured abstracts of no more than 4-80 words should accompany each manuscript. Abstracts for original contributions should be structured into the following sections. AIM (no more than 20 words): Only the purpose should be included. Please write the aim as the form of "To investigate/ study/..."; MATERIALS AND METHODS (no more than 140 words); RESULTS (no more than 294 words): You should present P values where appropnate and must provide relevant data to illustrate how they were obtained, e.g. 6.92 ± 3.86 vs 3.61 ± 1.67, P< 0.001; CONCLUSION (no more than 26 words).

  5. Fine-scale patterns of odor encounter by the antennules of mantis shrimp tracking turbulent plumes in wave-affected and unidirectional flow.

    Science.gov (United States)

    Mead, Kristina S; Wiley, Megan B; Koehl, M A R; Koseff, Jeffrey R

    2003-01-01

    Many marine animals track odor plumes to their source. Although studies of plume-tracking behavior have been performed in unidirectional flow, benthic animals such as crustaceans live in coastal habitats characterized by waves. We compared signal encounters by odor-plume-tracking stomatopods (mantis shrimp) in wave-affected and unidirectional flow in a flume. Stomatopods are small enough that we can study their natural behavior in a flume. They sample odors by flicking their antennules. A thin sheet of laser light illuminating an odor plume labeled with dye [planar laser induced fluorescence (PLIF) technique] permitted us to measure the instantaneous odor concentration encountered by the animal's chemosensory organs (antennules) while it tracked the plume. We simultaneously measured behavior and the high-resolution odor signal at the spatial and temporal scale of the animal. We found that the navigating animal encountered odor filaments more often in wave-affected flow than in unidirectional flow. Odor filaments along the animals' antennules were significantly wider and of higher concentration in waves than in unidirectional flow.

  6. A dendritic mechanism for decoding traveling waves: principles and applications to motor cortex.

    Directory of Open Access Journals (Sweden)

    Stewart Heitmann

    2013-10-01

    Full Text Available Traveling waves of neuronal oscillations have been observed in many cortical regions, including the motor and sensory cortex. Such waves are often modulated in a task-dependent fashion although their precise functional role remains a matter of debate. Here we conjecture that the cortex can utilize the direction and wavelength of traveling waves to encode information. We present a novel neural mechanism by which such information may be decoded by the spatial arrangement of receptors within the dendritic receptor field. In particular, we show how the density distributions of excitatory and inhibitory receptors can combine to act as a spatial filter of wave patterns. The proposed dendritic mechanism ensures that the neuron selectively responds to specific wave patterns, thus constituting a neural basis of pattern decoding. We validate this proposal in the descending motor system, where we model the large receptor fields of the pyramidal tract neurons - the principle outputs of the motor cortex - decoding motor commands encoded in the direction of traveling wave patterns in motor cortex. We use an existing model of field oscillations in motor cortex to investigate how the topology of the pyramidal cell receptor field acts to tune the cells responses to specific oscillatory wave patterns, even when those patterns are highly degraded. The model replicates key findings of the descending motor system during simple motor tasks, including variable interspike intervals and weak corticospinal coherence. By additionally showing how the nature of the wave patterns can be controlled by modulating the topology of local intra-cortical connections, we hence propose a novel integrated neuronal model of encoding and decoding motor commands.

  7. Tango waves in a bidomain model of fertilization calcium waves

    Science.gov (United States)

    Li, Yue-Xian

    2003-12-01

    Fertilization of an egg cell is marked by one or several Ca 2+ waves that travel across the intra-cellular space, called fertilization Ca 2+ waves. Patterns of Ca 2+ waves observed in mature or immature oocytes include traveling fronts and pulses as well as concentric and spiral waves. These patterns have been studied in other excitable media in physical, chemical, and biological systems. Here, we report the discovery of a new wave phenomenon in the numerical study of a bidomain model of fertilization Ca 2+ waves. This wave is a front that propagates in a back-and-forth manner that resembles the movement of tango dancers, thus is called a tango wave. When the medium is excitable, a forward-moving tango wave can generate traveling pulses that propagate down the space without reversal. The study shows that the occurrence of tango waves is related to spatial inhomogeneity in the local dynamics. This is tested and confirmed by simulating similar waves in a medium with stationary spatial inhomogeneity. Similar waves are also obtained in a FitzHugh-Nagumo system with a linear spatial ramp. In both the bidomain model of Ca 2+ waves and the FitzHugh-Nagumo system, the front is stable when the slope of a linear ramp is large. As the slope decreases beyond a critical value, front oscillations occur. The study shows that tango waves facilitate the dispersion of localized Ca 2+. Key features of the bidomain model underlying the occurrence of tango waves are revealed. These features are commonly found in egg cells of a variety of species. Thus, we predict that tango waves can occur in real egg cells provided that a slowly varying inhomogeneity does occur following the sperm entry. The observation of tango wave-like waves in nemertean worm and ascidian eggs seems to support such a prediction.

  8. The effect of multiple anisotropic scattering pattern on S wave energy density envelope%多次各向异性散射模式对S波能量密度包络曲线的影响

    Institute of Scientific and Technical Information of China (English)

    景月岭; Yuehua Zeng; 林皋; Genda Chen; 李建波

    2012-01-01

    在多次各向异性散射理论的基础上,本文重新推导了方向性散射系数的球函数展开式.引入特征时间的概念,来定义震源处初始地震波脉冲宽度,并在地震波能量密度积分方程中引入任意给定频率的初始脉冲能量谱密度的解析表达.通过离散波数方法求解了修正的地震波能量密度积分方程.基于积分方程的数值解,研究了不同散射模式对S波能量密度包络曲线的影响.计算结果表明:随着震源距的增加,在S波到时之后,多次各向异性散射模式与多次各向同性散射模式合成的能量密度包络差异逐渐增大.其中通过多次前散射模式,我们可以得到不同震源距的尾波能量密度包络的同一衰减趋势,以及S波能量密度包络随着震源距的增加而出现的展宽现象.最后,利用美国内华达州Wells地震余震的台站记录验证了多次前散射模式的实用性与有效性.%Based on the multiple anisotropic scattering theory, we reevaluate the spherical harmonic series expansion of directional scattering coefficient. A characteristic source time is introduced to define the initial impulse width of energy density at the source. We use an analytical expression of the initial spectral energy intensity in the integral equation of seismic wave energy density at any given frequency. The modified integral equation is solved by a discrete wave number method. Based on this solution, we investigate the effect of scattering pattern on S wave energy density envelope. And the numerical simulation shows that after the S arrival time the difference of the energy density envelope between the multiple anisotropic scattering pattern and the isotropic scattering pattern increases with distances. Using forward anisotropic scattering pattern, we successfully reproduce the common decay of the seismic coda wave energy density envelopes at different hypocentral distances. For the same pattern, the S wave energy density

  9. Nonlinear elastic waves in materials

    CERN Document Server

    Rushchitsky, Jeremiah J

    2014-01-01

    The main goal of the book is a coherent treatment of the theory of propagation in materials of nonlinearly elastic waves of displacements, which corresponds to one modern line of development of the nonlinear theory of elastic waves. The book is divided on five basic parts: the necessary information on waves and materials; the necessary information on nonlinear theory of elasticity and elastic materials; analysis of one-dimensional nonlinear elastic waves of displacement – longitudinal, vertically and horizontally polarized transverse plane nonlinear elastic waves of displacement; analysis of one-dimensional nonlinear elastic waves of displacement – cylindrical and torsional nonlinear elastic waves of displacement; analysis of two-dimensional nonlinear elastic waves of displacement – Rayleigh and Love nonlinear elastic surface waves. The book is addressed first of all to people working in solid mechanics – from the students at an advanced undergraduate and graduate level to the scientists, professional...

  10. Freeform Fabrication of Magnetophotonic Crystals with Diamond Lattices of Oxide and Metallic Glasses for Terahertz Wave Control by Micro Patterning Stereolithography and Low Temperature Sintering

    Directory of Open Access Journals (Sweden)

    Maasa Nakano

    2013-04-01

    Full Text Available Micrometer order magnetophotonic crystals with periodic arranged metallic glass and oxide glass composite materials were fabricated by stereolithographic method to reflect electromagnetic waves in terahertz frequency ranges through Bragg diffraction. In the fabrication process, the photo sensitive acrylic resin paste mixed with micrometer sized metallic glass of Fe72B14.4Si9.6Nb4 and oxide glass of B2O3·Bi2O3 particles was spread on a metal substrate, and cross sectional images of ultra violet ray were exposed. Through the layer by layer stacking, micro lattice structures with a diamond type periodic arrangement were successfully formed. The composite structures could be obtained through the dewaxing and sintering process with the lower temperature under the transition point of metallic glass. Transmission spectra of the terahertz waves through the magnetophotonic crystals were measured by using a terahertz time domain spectroscopy.

  11. Is rich and rare the common share? Describing biodiversity patterns to inform conservation practices for South American anurans.

    Directory of Open Access Journals (Sweden)

    Fabricio Villalobos

    Full Text Available Species richness and range size are key features of biogeographic and macroecological analyses, which can yield a first assessment tool to define conservation priorities. Here we combined both features in a simultaneous analysis, based on range-diversity plots, to identify sets of rich-rare (high species richness with restricted ranges and poor-rare cells (low species richness with restricted ranges. We applied this analysis to the anurans of South America and evaluated the representation of those sets of cells within the protected area system. South American anurans showed high species richness in the Brazilian Atlantic Forest and East Tropical Andes, while regions harboring most of the rare species were concentrated in the Andes and Atlantic Coast from North-Eastern Brazil to River Plate. Based on such patterns, we identified as rich-rare cells the Brazilian Atlantic Forest and Tropical Andes and as poor-rare cells the southern part of Andes and Uruguay. A low fraction of both sets of cells was represented within the protected area system. We show that a simultaneous consideration of species richness and rarity provides a rapid assessment of large-scale biodiversity patterns and may contribute to the definition of conservation priorities.

  12. Is rich and rare the common share? Describing biodiversity patterns to inform conservation practices for South American anurans.

    Science.gov (United States)

    Villalobos, Fabricio; Dobrovolski, Ricardo; Provete, Diogo B; Gouveia, Sidney F

    2013-01-01

    Species richness and range size are key features of biogeographic and macroecological analyses, which can yield a first assessment tool to define conservation priorities. Here we combined both features in a simultaneous analysis, based on range-diversity plots, to identify sets of rich-rare (high species richness with restricted ranges) and poor-rare cells (low species richness with restricted ranges). We applied this analysis to the anurans of South America and evaluated the representation of those sets of cells within the protected area system. South American anurans showed high species richness in the Brazilian Atlantic Forest and East Tropical Andes, while regions harboring most of the rare species were concentrated in the Andes and Atlantic Coast from North-Eastern Brazil to River Plate. Based on such patterns, we identified as rich-rare cells the Brazilian Atlantic Forest and Tropical Andes and as poor-rare cells the southern part of Andes and Uruguay. A low fraction of both sets of cells was represented within the protected area system. We show that a simultaneous consideration of species richness and rarity provides a rapid assessment of large-scale biodiversity patterns and may contribute to the definition of conservation priorities.

  13. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...

  14. The Value of Information and Geospatial Technologies for the analysis of tidal current patterns in the Guanabara Bay (Rio de Janeiro)

    Science.gov (United States)

    Isotta Cristofori, Elena; Demarchi, Alessandro; Facello, Anna; Cámaro, Walther; Hermosilla, Fernando; López, Jaime

    2016-04-01

    The study and validation of tidal current patterns relies on the combination of several data sources such as numerical weather prediction models, hydrodynamic models, weather stations, current drifters and remote sensing observations. The assessment of the accuracy and the reliability of produced patterns and the communication of results, including an easy to understand visualization of data, is crucial for a variety of stakeholders including decision-makers. The large diffusion of geospatial equipment such as GPS, current drifters, aerial photogrammetry, allows to collect data in the field using mobile and portable devices with a relative limited effort in terms of time and economic resources. Theses real-time measurements are essential in order to validate the models and specifically to assess the skill of the model during critical environmental conditions. Moreover, the considerable development in remote sensing technologies, cartographic services and GPS applications have enabled the creation of Geographic Information Systems (GIS) capable to store, analyze, manage and integrate spatial or geographical information with hydro-meteorological data. This valuable contribution of Information and geospatial technologies can benefit manifold decision-makers including high level sport athletes. While the numerical approach, commonly used to validate models with in-situ data, is more familiar for scientific users, high level sport users are not familiar with a numerical representations of data. Therefore the integration of data collected in the field into a GIS allows an immediate visualization of performed analysis into geographic maps. This visualization represents a particularly effective way to communicate current patterns assessment results and uncertainty in information, leading to an increase of confidence level about the forecast. The aim of this paper is to present the methodology set-up in collaboration with the Austrian Sailing Federation, for the study of

  15. Towards Evidence-based Precision Medicine: Extracting Population Information from Biomedical Text using Binary Classifiers and Syntactic Patterns

    Science.gov (United States)

    Raja, Kalpana; Dasot, Naman; Goyal, Pawan; Jonnalagadda, Siddhartha R

    2016-01-01

    Precision Medicine is an emerging approach for prevention and treatment of disease that considers individual variability in genes, environment, and lifestyle for each person. The dissemination of individualized evidence by automatically identifying population information in literature is a key for evidence-based precision medicine at the point-of-care. We propose a hybrid approach using natural language processing techniques to automatically extract the population information from biomedical literature. Our approach first implements a binary classifier to classify sentences with or without population information. A rule-based system based on syntactic-tree regular expressions is then applied to sentences containing population information to extract the population named entities. The proposed two-stage approach achieved an F-score of 0.81 using a MaxEnt classifier and the rule- based system, and an F-score of 0.87 using a Nai've-Bayes classifier and the rule-based system, and performed relatively well compared to many existing systems. The system and evaluation dataset is being released as open source. PMID:27570671

  16. Prenatal thalamic waves regulate cortical area size prior to sensory processing

    Science.gov (United States)

    Moreno-Juan, Verónica; Filipchuk, Anton; Antón-Bolaños, Noelia; Mezzera, Cecilia; Gezelius, Henrik; Andrés, Belen; Rodríguez-Malmierca, Luis; Susín, Rafael; Schaad, Olivier; Iwasato, Takuji; Schüle, Roland; Rutlin, Michael; Nelson, Sacha; Ducret, Sebastien; Valdeolmillos, Miguel; Rijli, Filippo M.; López-Bendito, Guillermina

    2017-01-01

    The cerebral cortex is organized into specialized sensory areas, whose initial territory is determined by intracortical molecular determinants. Yet, sensory cortical area size appears to be fine tuned during development to respond to functional adaptations. Here we demonstrate the existence of a prenatal sub-cortical mechanism that regulates the cortical areas size in mice. This mechanism is mediated by spontaneous thalamic calcium waves that propagate among sensory-modality thalamic nuclei up to the cortex and that provide a means of communication among sensory systems. Wave pattern alterations in one nucleus lead to changes in the pattern of the remaining ones, triggering changes in thalamic gene expression and cortical area size. Thus, silencing calcium waves in the auditory thalamus induces Rorβ upregulation in a neighbouring somatosensory nucleus preluding the enlargement of the barrel-field. These findings reveal that embryonic thalamic calcium waves coordinate cortical sensory area patterning and plasticity prior to sensory information processing. PMID:28155854

  17. Sound Waves Levitate Substrates

    Science.gov (United States)

    Lee, M. C.; Wang, T. G.

    1982-01-01

    System recently tested uses acoustic waves to levitate liquid drops, millimeter-sized glass microballoons, and other objects for coating by vapor deposition or capillary attraction. Cylindrical contactless coating/handling facility employs a cylindrical acoustic focusing radiator and a tapered reflector to generate a specially-shaped standing wave pattern. Article to be processed is captured by the acoustic force field under the reflector and moves as reflector is moved to different work stations.

  18. Landscape-scale GPP and carbon density inform patterns and impacts of an invasive tree across wet forests of Hawaii.

    Science.gov (United States)

    Barbosa, Jomar M; Asner, Gregory P; Hughes, R Flint; Johnson, M Tracy

    2017-03-01

    Plant invasion typically occurs within a landscape-scale framework of abiotic and biotic conditions, often resulting in emergent feedbacks among environment, ecosystem functions, and the dominance of invasive species. Understanding the mechanisms underlying successful invasions is an important component of conservation and management efforts, but this has been poorly investigated in a spatially explicit manner. Knowing where and why invasion patterns change throughout the landscape enables managers to use context-specific controls on the spread of invasive species. Using high-resolution airborne imaging spectroscopy, we studied plant performance in growth within and across landscapes to examine the dominance and spatial distribution of an invasive tree, Psidium cattleianum (strawberry guava), in heterogeneous environmental conditions of a submontane Hawaiian tropical forest. We assessed invader performance using the GPP ratio index, which is the relative difference in remotely sensed estimates of gross primary productivity between canopies of guava and canopies of the invaded plant community. In addition, we used airborne LiDAR data to evaluate the impacts of guava invasion on the forest aboveground carbon density in different environments. Structural equation modeling revealed that substrate type and elevation above sea level interact and amplify landscape-scale differences in productivity between the invasive species and the host plant community (GPP ratio); differences that ultimately control levels of dominance of guava. We found shifts in patterns of forest carbon storage based on both gradual increase of invader dominance and changes in environmental conditions. Overall, our results demonstrate that the remotely sensed index defined as the GPP ratio provided an innovative spatially explicit approach to track and predict the success of invasive plants based in their canopy productivity, particularly within a landscape-scale framework of varying environmental

  19. Forging patterns and making waves from biology to geology: a commentary on Turing (1952) ‘The chemical basis of morphogenesis’

    Science.gov (United States)

    Ball, Philip

    2015-01-01

    Alan Turing was neither a biologist nor a chemist, and yet the paper he published in 1952, ‘The chemical basis of morphogenesis’, on the spontaneous formation of patterns in systems undergoing reaction and diffusion of their ingredients has had a substantial impact on both fields, as well as in other areas as disparate as geomorphology and criminology. Motivated by the question of how a spherical embryo becomes a decidedly non-spherical organism such as a human being, Turing devised a mathematical model that explained how random fluctuations can drive the emergence of pattern and structure from initial uniformity. The spontaneous appearance of pattern and form in a system far away from its equilibrium state occurs in many types of natural process, and in some artificial ones too. It is often driven by very general mechanisms, of which Turing's model supplies one of the most versatile. For that reason, these patterns show striking similarities in systems that seem superficially to share nothing in common, such as the stripes of sand ripples and of pigmentation on a zebra skin. New examples of ‘Turing patterns' in biology and beyond are still being discovered today. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750229

  20. A criterion based on an information theoretic measure for goodness of fit between classifier and data base. [in pattern recognition

    Science.gov (United States)

    Eigen, D. J.; Davida, G. I.; Northouse, R. A.

    1974-01-01

    A criterion for characterizing an iteratively trained classifier is presented. The criterion is based on an information theoretic measure that is developed from modeling classifier training iterations as a set of cascaded channels. The criterion is formulated as a figure of merit and as a performance index to check the appropriateness of application of the characterized classifier to an unknown data base and for implementing classifier updates and data selection, respectively.

  1. Informal caregivers of clients with neurological conditions: profiles, patterns and risk factors for distress from a home care prevalence study

    OpenAIRE

    Mitchell, Lori A.; Hirdes, John; Poss, Jeff W.; Slegers-Boyd, Caroline; Caldarelli, Hilary; Martin, Lynn

    2015-01-01

    Background Individuals living in the community with neurological conditions receive the majority of their care from informal caregivers. The purpose of this project was to provide a profile of caregivers of home care clients with neurological conditions. The study also examined prevalence of caregiver distress and the association between neurological conditions and other client and caregiver characteristics with distress. Methods The study population included Canadian home care clients in the...

  2. Conditional Second Order Short-crested Water Waves Applied to Extreme Wave Episodes

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2005-01-01

    A derivation of the mean second order short-crested wave pattern and associated wave kinematics, conditional on a given magnitude of the wave crest, is presented. The analysis is based on the second order Sharma and Dean finite water wave theory. A comparison with a measured extreme wave profile......, the Draupner New Year Wave, shows a good agreement in the mean, indicating that this second order wave can be a good identifier of the shape and occurrence of extreme wave events. A discussion on its use as an initial condition for a fully non-linear three-dimensional surface wave analysis is given....

  3. MHD waves in sunspots

    CERN Document Server

    Sych, Robert

    2015-01-01

    The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed emission variability. Dynamic of sunspot wave processes, provides the information about the structure of wave fronts and their time variations, investigates the oscillation frequency transformation depending on the wave energy is shown. The initializing solar flares caused by trigger agents like magnetoacoustic waves, accelerated particle beams, and shocks are discussed. Special attention is paid to the relation between the flare reconnection periodic initialization and the dynamics of sunspot slow magnetoacoustic waves. A short review of theoretical models of sunspot oscillations is provided.

  4. The contribution of ventricular apicobasal and transmural repolarization patterns to the development of the T wave body surface potentials in frogs (Rana temporaria) and pike (Esox lucius).

    Science.gov (United States)

    Vaykshnorayte, Marina A; Azarov, Jan E; Tsvetkova, Alena S; Vityazev, Vladimir A; Ovechkin, Alexey O; Shmakov, Dmitry N

    2011-05-01

    The study aimed at the simultaneous determination of the transmural and apicobasal differences in the repolarization timing and the comparison of the contributions of these two repolarization gradients to the development of the body surface T wave potentials in animals with the single heart ventricle (fishes and amphibians). Unipolar potentials were measured on the body surface, epicardium and in the intramural (subepicardial, Epi; midmyocardial; and subendocardial, Endo) ventricular layers of 9 pike and 8 frogs. Activation times, repolarization times and activation-recovery intervals were determined. A transmural gradient in repolarization durations in frogs (Endo>Epi, Ppike that produces a repolarization sequence from Endo to Epi (Endopike and frogs.

  5. Gravitational waves and electrodynamics: new perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Francisco; Lobo, Francisco S.N. [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal)

    2017-04-15

    Given the recent direct measurement of gravitational waves (GWs) by the LIGO-VIRGO collaboration, the coupling between electromagnetic fields and gravity have a special relevance since it opens new perspectives for future GW detectors and also potentially provides information on the physics of highly energetic GW sources. We explore such couplings using the field equations of electrodynamics on (pseudo) Riemann manifolds and apply it to the background of a GW, seen as a linear perturbation of Minkowski geometry. Electric and magnetic oscillations are induced that propagate as electromagnetic waves and contain information as regards the GW which generates them. The most relevant results are the presence of longitudinal modes and dynamical polarization patterns of electromagnetic radiation induced by GWs. These effects might be amplified using appropriate resonators, effectively improving the signal to noise ratio around a specific frequency. We also briefly address the generation of charge density fluctuations induced by GWs and the implications for astrophysics. (orig.)

  6. Gravitational waves and electrodynamics: new perspectives

    Science.gov (United States)

    Cabral, Francisco; Lobo, Francisco S. N.

    2017-04-01

    Given the recent direct measurement of gravitational waves (GWs) by the LIGO-VIRGO collaboration, the coupling between electromagnetic fields and gravity have a special relevance since it opens new perspectives for future GW detectors and also potentially provides information on the physics of highly energetic GW sources. We explore such couplings using the field equations of electrodynamics on (pseudo) Riemann manifolds and apply it to the background of a GW, seen as a linear perturbation of Minkowski geometry. Electric and magnetic oscillations are induced that propagate as electromagnetic waves and contain information as regards the GW which generates them. The most relevant results are the presence of longitudinal modes and dynamical polarization patterns of electromagnetic radiation induced by GWs. These effects might be amplified using appropriate resonators, effectively improving the signal to noise ratio around a specific frequency. We also briefly address the generation of charge density fluctuations induced by GWs and the implications for astrophysics.

  7. Stochastic self-similarity of envelopes of high-frequency teleseismic P-waves from large earthquakes suggests fractal pattern for earthquake rupture

    CERN Document Server

    Gusev, A A

    2008-01-01

    High-frequency (HF) seismic radiation of large earthquakes is approximately represented by P wave trains recorded at teleseismic distances. Observed envelopes of such signals look random and intermittent, suggesting non-trivial stochastic structure. Variogram and spectral analyses were applied to instant power calculated from band-filtered observed P-wave signals from eight large (Mw=7.6-9.2) earthquakes, with 8-30 records per event and eight non-overvlapping frequency bands analyzed (total frequency range 0.6-6.2 Hz, bandwidth 0.7 Hz). Estimates for both variograms and power spectra look linear in log-log scale, suggesting in most cases self-similar correlation structure of the signal. The range for the individual-event values of the Hurst exponent H is 0.71-0.80 (averaged over bands and stations) when estimated from variograms, and 0.78-0.83 when estimated from spectra. No systematic dependence on station or frequency band was noticed. The values of H around 0.8 may be characteristic for large earthquakes i...

  8. 10 GHz bandstop microstrip filter using excitation of magnetostatic surface wave in a patterned Ni78Fe22 ferromagnetic film

    NARCIS (Netherlands)

    Vroubel, M.; Zhuang, Y.; Rejaei, B.; Burghartz, J.N.

    2006-01-01

    Various microstrips with a ferromagnetic core were designed and fabricated on a silicon substrate. The core was formed by a 0.5-μm-thick Ni78Fe22 film, patterned into rectangular prisms. Measurement results for attenuation constant versus frequency show a peak value of ∼ 50 dB/cm around 10 GHz. Elec

  9. Probability mapping to determine the spatial risk pattern of acute gastroenteritis in Coimbatore District, India, using Geographic Information Systems (GIS

    Directory of Open Access Journals (Sweden)

    Pawlin Vasanthi Joseph

    2015-01-01

    Full Text Available Background: Maps show well the spatial configuration of information. Considerable effort is devoted to the development of geographical information systems (GIS that increase understanding of public health problems and in particular to collaborate efforts among clinicians, epidemiologists, ecologists, and geographers to map and forecast disease risk. Objectives: Small populations tend to give rise to the most extreme disease rates, even if the actual rates are similar across the areas. Such situations will follow the decision-maker′s attention on these areas when they scrutinize the map for decision making or resource allocation. As an alternative, maps can be prepared using P-values (probabilistic values. Materials and Methods: The statistical significance of rates rather than the rates themselves are used to map the results. The incidence rates calculated for each village from 2000 to 2009 is used to estimate λ, the expected number of cases in the study area. The obtained results are mapped using Arc GIS 10.0. Results: The likelihood of infections from low to high is depicted in the map and it is observed that five villages namely, Odanthurai, Coimbatore Corporation, Ikkaraiboluvampatti, Puliakulam, and Pollachi Corporation are more likely to have significantly high incidences. Conclusion: In the probability map, some of the areas with exceptionally high or low rates disappear. These are typically small unpopulated areas, whose rates are unstable due to the small numbers problem. The probability map shows more specific regions of relative risks and expected outcomes.

  10. Determination of distribution pattern of the heavy metal concentrations in the potable network of Gachsaran by Geographical Information System (GIS

    Directory of Open Access Journals (Sweden)

    G Paraham

    2013-12-01

    . Methods: In this descriptive, cross-sectional study, samples were taken from11 spots of the drinking water distribution network and tested for concentration of 10 metals by Inductivity Coupled Ions Plasma (ICP method in summer of 2010. The research data were compared with national and international water standards. Then the distribution map of heavy metals concentrations in the drinking water wells of the region was prepared by using the Geographical Information System (GIS software. Data were analyzed by the Kruskal-Wallis tests. Results: In all samples, the average concentration of heavy metals were: Arsenic 0.54, Cadmium 0.05, Zinc 55.9, Lead 0.18, Copper .82, Chromium 1.6, Barium 36.5, Selenium0.5, Mercury 0.1 and Silver 0.05 micrograms per liter and was less than the water quality standard. Conclusion: Based on the results obtained, it can be concluded that concentrations of heavy metals in Gachsaran’s drinking water distribution network are not higher than national and international standards and therefore not harmful for people. Key words: Heavy metals, Distribution network, Gachsaran, geographical information system (GIS

  11. Benchmark Modeling of the Near-Field and Far-Field Wave Effects of Wave Energy Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rhinefrank, Kenneth E; Haller, Merrick C; Ozkan-Haller, H Tuba

    2013-01-26

    This project is an industry-led partnership between Columbia Power Technologies and Oregon State University that will perform benchmark laboratory experiments and numerical modeling of the near-field and far-field impacts of wave scattering from an array of wave energy devices. These benchmark experimental observations will help to fill a gaping hole in our present knowledge of the near-field effects of multiple, floating wave energy converters and are a critical requirement for estimating the potential far-field environmental effects of wave energy arrays. The experiments will be performed at the Hinsdale Wave Research Laboratory (Oregon State University) and will utilize an array of newly developed Buoys' that are realistic, lab-scale floating power converters. The array of Buoys will be subjected to realistic, directional wave forcing (1:33 scale) that will approximate the expected conditions (waves and water depths) to be found off the Central Oregon Coast. Experimental observations will include comprehensive in-situ wave and current measurements as well as a suite of novel optical measurements. These new optical capabilities will include imaging of the 3D wave scattering using a binocular stereo camera system, as well as 3D device motion tracking using a newly acquired LED system. These observing systems will capture the 3D motion history of individual Buoys as well as resolve the 3D scattered wave field; thus resolving the constructive and destructive wave interference patterns produced by the array at high resolution. These data combined with the device motion tracking will provide necessary information for array design in order to balance array performance with the mitigation of far-field impacts. As a benchmark data set, these data will be an important resource for testing of models for wave/buoy interactions, buoy performance, and far-field effects on wave and current patterns due to the presence of arrays. Under the proposed project we will initiate

  12. Local Scour Around Piles Under Wave Action

    Institute of Scientific and Technical Information of China (English)

    陈国平; 左其华; 黄海龙

    2004-01-01

    The model tests are performed with regular waves, and the effect of wave height, wave period, water depth, scdiment size and pile diameter is evaluated. The shape and size of local scour around piles are studied. There are three typical scour patterns due to wave action. It is found that a relationship exists between the erosion depth and the wave number. An empirical formula of the maximum local scour is thus derived.

  13. The Coriolis Interaction between the v2 = 1 and v3 = 2 States of Nitrosyl Bromide: Anomalous Quadrupole Patterns and Interstate Transitions in the Millimeter-Wave Spectrum.

    Science.gov (United States)

    Esposti; Fuganti; Kisiel; Tamassia

    1998-10-01

    The millimeter-wave rotational spectra of 79BrNO and 81BrNO in the v2 = 1 and v3 = 2 vibrational states have been reinvestigated. Measurements of the rotational spectrum in the region of maximum c-type Coriolis interaction between the two states allowed the previous analysis to be extended to account for some uncommon effects. For the most perturbed transitions the nuclear quadrupole hyperfine structure arises from coupling of not only the bromine nucleus, but also the nitrogen nucleus with the rotational angular momentum. These effects were satisfactorily fitted with a Hamiltonian describing Coriolis coupling in a molecule with two quadrupolar nuclei. The successful analysis of pure rotational transitions then allowed accurate prediction of rovibrational transitions, six of which were measured for 79BrNO and four for 81BrNO. Copyright 1998 Academic Press.

  14. Angular pattern of interferometers for scalar gravitational waves in the gauge of the local observer used for a potential detection of a stochastic bacground with advanced LIGO

    CERN Document Server

    Corda, C

    2006-01-01

    Recently, with the ``bounching photon'' treatment, the gauge invariance of the response of an interferometer to scalar gravitational waves (SGWs) has been demonstred in its full frequency dependence in three different gauges well known in literature, while in previous works it was been shown only in the low frequencies approximation. In this paper the analysis of the response function for SGWs is generalized in its full angular dependence and directly in the gauge of the local observer, which is the gauge of a laboratory enviroment on Earth. The result is used for anlyzing the cross - correlation between the two LIGO interferometers in their advanced configuration for a potential detection of a stochastic bacground of SGWs. An inferior limit for the integration time of a potential detection is released.

  15. Beneficial effects of semantic memory support on older adults' episodic memory: Differential patterns of support of item and associative information.

    Science.gov (United States)

    Mohanty, Praggyan Pam; Naveh-Benjamin, Moshe; Ratneshwar, Srinivasan

    2016-02-01

    The effects of two types of semantic memory support-meaningfulness of an item and relatedness between items-in mitigating age-related deficits in item and associative, memory are examined in a marketing context. In Experiment 1, participants studied less (vs. more) meaningful brand logo graphics (pictures) paired with meaningful brand names (words) and later were assessed by item (old/new) and associative (intact/recombined) memory recognition tests. Results showed that meaningfulness of items eliminated age deficits in item memory, while equivalently boosting associative memory for older and younger adults. Experiment 2, in which related and unrelated brand logo graphics and brand name pairs served as stimuli, revealed that relatedness between items eliminated age deficits in associative memory, while improving to the same degree item memory in older and younger adults. Experiment 2 also provided evidence for a probable boundary condition that could reconcile seemingly contradictory extant results. Overall, these experiments provided evidence that although the two types of semantic memory support can improve both item and associative memory in older and younger adults, older adults' memory deficits can be eliminated when the type of support provided is compatible with the type of information required to perform well on the test. (c) 2016 APA, all rights reserved).

  16. Modality-specific spectral dynamics in response to visual and tactile sequential shape information processing tasks: An MEG study using multivariate pattern classification analysis.

    Science.gov (United States)

    Gohel, Bakul; Lee, Peter; Jeong, Yong

    2016-08-01

    Brain regions that respond to more than one sensory modality are characterized as multisensory regions. Studies on the processing of shape or object information have revealed recruitment of the lateral occipital cortex, posterior parietal cortex, and other regions regardless of input sensory modalities. However, it remains unknown whether such regions show similar (modality-invariant) or different (modality-specific) neural oscillatory dynamics, as recorded using magnetoencephalography (MEG), in response to identical shape information processing tasks delivered to different sensory modalities. Modality-invariant or modality-specific neural oscillatory dynamics indirectly suggest modality-independent or modality-dependent participation of particular brain regions, respectively. Therefore, this study investigated the modality-specificity of neural oscillatory dynamics in the form of spectral power modulation patterns in response to visual and tactile sequential shape-processing tasks that are well-matched in terms of speed and content between the sensory modalities. Task-related changes in spectral power modulation and differences in spectral power modulation between sensory modalities were investigated at source-space (voxel) level, using a multivariate pattern classification (MVPC) approach. Additionally, whole analyses were extended from the voxel level to the independent-component level to take account of signal leakage effects caused by inverse solution. The modality-specific spectral dynamics in multisensory and higher-order brain regions, such as the lateral occipital cortex, posterior parietal cortex, inferior temporal cortex, and other brain regions, showed task-related modulation in response to both sensory modalities. This suggests modality-dependency of such brain regions on the input sensory modality for sequential shape-information processing.

  17. Classification of cardiac excitation patterns during atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Reich Christian

    2016-09-01

    Full Text Available The goal of this research was to classify cardiac excitation patterns during atrial fibrillation (AFib. For this purpose, virtual models of intracardiac mapping catheters were moved across in-silico cardiac tissue to extract local activation times (LATs of each catheter electrode from simulated cardiac action potential (AP signals. The resulting LAT patterns consisting of the LATs of all electrodes resemble patterns measured in clinical cases. The LATs represent the input information for features that were used to separate four different excitation patterns during AFib. Those four excitation patterns were plane wave, ectopic focus (spherical wave, rotor (spiral wave and block. A feature selection algorithm was used to investigate the features concerning their power to classify the different simulated excitation patterns. The scores of the selected features were used to train and optimize a support vector machine (SVM. The optimized and cross-validated SVM was then used to classify the simulated cardiac excitation patterns. The achieved overall classification accuracy of this SVM model was 98.4 %.

  18. A sand wave simulation model

    NARCIS (Netherlands)

    Nemeth, A.A.; Hulscher, S.J.M.H.; Damme, van R.M.J.

    2003-01-01

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water su

  19. Regeneration of dredged sand waves

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; Knaapen, Michiel; Scholl, Olaf; Scholl, O.; Trenteseaux., A.; Garlan, T.

    2000-01-01

    Sand waves form a wavy pattern in the offshore sandy seabed. Since their crests reduce the navigability, it is important to know their evolution. A simple model is presented to estimate the recovery of sand wave amplitudes. This model is partially based on the similarity with sea ripples and

  20. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  1. Identifying drug-induced repolarization abnormalities from distinct ECG patterns in congenital long QT syndrome: a study of sotalol effects on T-wave morphology

    DEFF Research Database (Denmark)

    Graff, Claus; Andersen, Mads P; Xue, Joel Q

    2009-01-01

    BACKGROUND: The electrocardiographic QT interval is used to identify drugs with potential harmful effects on cardiac repolarization in drug trials, but the variability of the measurement can mask drug-induced ECG changes. The use of complementary electrocardiographic indices of abnormal repolariz......BACKGROUND: The electrocardiographic QT interval is used to identify drugs with potential harmful effects on cardiac repolarization in drug trials, but the variability of the measurement can mask drug-induced ECG changes. The use of complementary electrocardiographic indices of abnormal...... are typical ECG patterns in LQT2. Blinded to labels, the new morphology measures were tested in a third group of 39 healthy subjects receiving sotalol. Over 3 days the sotalol group received 0, 160 and 320 mg doses, respectively, and a 12-lead Holter ECG was recorded for 22.5 hours each day. Drug...... with QTcF, p ECG patterns in LQT2 carriers effectively quantified repolarization changes induced by sotalol. Further studies are needed to validate whether this measure has...

  2. Polytypic pattern matching

    NARCIS (Netherlands)

    Jeuring, J.T.

    2007-01-01

    The pattern matching problem can be informally specified as follows: given a pattern and a text, find all occurrences of the pattern in the text. The pattern and the text may both be lists, or they may both be trees, or they may both be multi-dimensional arrays, etc. This paper describes a general p

  3. Gravitational waves from inflation

    CERN Document Server

    Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino

    2016-01-01

    The production of a stochastic background of gravitational waves is a fundamental prediction of any cosmological inflationary model. The features of such a signal encode unique information about the physics of the Early Universe and beyond, thus representing an exciting, powerful window on the origin and evolution of the Universe. We review the main mechanisms of gravitational-wave production, ranging from quantum fluctuations of the gravitational field to other mechanisms that can take place during or after inflation. These include e.g. gravitational waves generated as a consequence of extra particle production during inflation, or during the (p)reheating phase. Gravitational waves produced in inflation scenarios based on modified gravity theories and second-order gravitational waves are also considered. For each analyzed case, the expected power-spectrum is given. We discuss the discriminating power among different models, associated with the validity/violation of the standard consistency relation between t...

  4. Long-term wave measurements in a climate change perspective.

    Science.gov (United States)

    Pomaro, Angela; Bertotti, Luciana; Cavaleri, Luigi; Lionello, Piero; Portilla-Yandun, Jesus

    2017-04-01

    large scale pattern, can provide related compact and meaningful information. In addition, the availability for the area of interest of a 20-year long dataset of directional spectra (in frequency and direction) offers an independent, but theoretically corresponding and significantly long dataset, allowing to penetrate the wave problem through different perspectives. In particular, we investigate the contribution of the individual wave systems that modulate the variability of waves in the Adriatic Sea. A characterization of wave conditions based on wave spectra in fact brings out a more detailed description of the different wave regimes, their associated meteorological conditions and their variation in time and geographical space.

  5. Application of complex network method to spatiotemporal patterns in a neuronal network

    Science.gov (United States)

    Wang, Rong; Li, Jiajia; Wang, Li; Yang, Yong; Lin, Pan; Wu, Ying

    2016-12-01

    Spiral waves have been found to appear alternatively with plane waves in the brain cerebral cortex, which has a significant effect on neuron firing behaviors. In this paper, we propose a functional firing network based on the correlated firing behaviors among neuronal populations and use the complex network method to investigate the effects of spiral waves and plane waves on the structure and function of the network. We first analyze the correlation coefficient and the largest eigenvalue of the functional firing network. We find a larger range distribution of correlation coefficients and greater largest eigenvalue of the functional firing network for spiral waves than those for plane waves, which indicates that spiral waves induce higher network synchronization. In addition, we explore the topological structure of the functional firing network using the complex network method. We find that the functional firing network for spiral waves has a larger degree and global efficiency and a lower modularity and characteristic path length than that for plane waves, revealing that spiral waves contribute to neural information transmission and strengthen the functional integration. Our work not only provides new insights for studying spatiotemporal patterns, but is also helpful for explaining the modulation of spiral waves on brain function.

  6. CyberLondon: A Virtual City for the Posthuman? Literary Reflections on the Changing Patterns of our Relationship with the Metropolis in the Information Era.

    Directory of Open Access Journals (Sweden)

    Maria Goicoechea de Joerge

    2010-08-01

    Full Text Available http://dx.doi.org/10.5007/1807-9288.2009v5n2p188 This paper explores the changing patterns of our relationship with the metropolis from the perspective of London-based writers that have shown an interest for cyberculture (Matt Whyman, Stella Duffy, Pat Cadigan, China Miéville. Taking as point of departure the collection of Internet stories edited by Maxim Jakubowski with authors from a variety of fields, including crime, mystery, science-fiction, fantasy, and even erotica, this paper will analyze how popular literature has understood the role of the city of London and its social networks in the new informational society. The theoretical approach used to read these short stories is indebted to the ideas of urban theorist and sociologist Manuel Castells and cyberculture theorist Donna Haraway.

  7. A Comparison in the Cultural Information Input Pattern Between Chinese and English%英汉词汇文化信息植入模式对比

    Institute of Scientific and Technical Information of China (English)

    冯学芳

    2015-01-01

    该文对比了英汉两种语言词汇文化信息植入模式的特点,认为汉语主要是通过词汇的合成法、象征意义和比附思维来增加词汇的文化内涵,而在英语词汇文化信息的植入中词缀法、词义延伸和转喻思维作用更明显。%This paper compares the pattern of lexical cultural information input between Chinese and English and finds that for Chi⁃nese, compounding, symbolic meaning and metaphorical thinking are the main means used to increase lexical cultural content , while in English affixation, extension of original lexical meaning and metonymical thinking play a more important role.

  8. Identification of environmental determinants for spatio-temporal patterns of norovirus outbreaks in Korea using a geographic information system and binary response models.

    Science.gov (United States)

    Kim, Jin Hwi; Lee, Dong Hoon; Joo, Yongsung; Zoh, Kyung Duk; Ko, Gwangpyo; Kang, Joo-Hyon

    2016-11-01

    Although norovirus outbreaks are well-recognized to have strong winter seasonality relevant to low temperature and humidity, the role of artificial human-made features within geographical areas in norovirus outbreaks has rarely been studied. The aim of this study is to assess the natural and human-made environmental factors favoring the occurrence of norovirus outbreaks using nationwide surveillance data. We used a geographic information system and binary response models to examine whether the norovirus outbreaks are spatially patterned and whether these patterns are associated with specific environmental variables including service levels of water supply and sanitation systems and land-use types. The results showed that small-scale low-tech local sewage treatment plants and winter sports areas were statistically significant factors favoring norovirus outbreaks. Compactness of the land development also affected the occurrence of norovirus outbreaks; transportation, water, and forest land-uses were less favored for effective transmission of norovirus, while commercial areas were associated with an increased rate of norovirus outbreaks. We observed associations of norovirus outbreaks with various outcomes of human activities, including discharge of poorly treated sewage, overcrowding of people during winter season, and compactness of land development, which might help prioritize target regions and strategies for the management of norovirus outbreaks. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Heat Waves

    Science.gov (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and ... having trouble with the heat. If a heat wave is predicted or happening… - Slow down. Avoid strenuous ...

  10. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

  11. PATTERN LEARNING AND CLUSTERING OF TRADITIONAL CHINESE MEDICINE PRESCRIPTION INFORMATION%中医方剂信息模式学习及方剂聚类

    Institute of Scientific and Technical Information of China (English)

    杨艳; 施少敏

    2011-01-01

    In this paper,a novel prescription concept model is proposed according to the features of TCM prescriptions information.By utilising the theory of machine learning ,the unstructured text features and it organisation forms of content are learned to derive the extraction pattern of prescription concept.This pattern learning method effectively resolves the poser of the extraction of prescription' s unstructured text,and is used in processing prescription texts for China - US Million Book Digital Library Project.Moreover,to cluster the extracted prescription attribute information exhumes the relationship between the medicine nature and efficacy of different prescriptions, and provides recommending services to Traditional Chinese Medicine prescription enquiry modules.%针对中医药方剂信息的特点提出了一种新型的方剂概念模型,并利用机器学习理论对非结构化的文本特征以及其内容组织形式加以学习,得到方剂概念的抽取模式.该模式学习的方法有效地解决了方剂非结构化文本抽取的难题,被用于中美百万册数字图书馆的方剂文本处理.而对抽取的方剂属性信息作聚类,则发掘了不同方剂药性药效间的联系,为中医药方剂查询模块提供推荐服务.

  12. Modeling spatial patterns of soil respiration in maize fields from vegetation and soil property factors with the use of remote sensing and geographical information system.

    Directory of Open Access Journals (Sweden)

    Ni Huang

    Full Text Available To examine the method for estimating the spatial patterns of soil respiration (Rs in agricultural ecosystems using remote sensing and geographical information system (GIS, Rs rates were measured at 53 sites during the peak growing season of maize in three counties in North China. Through Pearson's correlation analysis, leaf area index (LAI, canopy chlorophyll content, aboveground biomass, soil organic carbon (SOC content, and soil total nitrogen content were selected as the factors that affected spatial variability in Rs during the peak growing season of maize. The use of a structural equation modeling approach revealed that only LAI and SOC content directly affected Rs. Meanwhile, other factors indirectly affected Rs through LAI and SOC content. When three greenness vegetation indices were extracted from an optical image of an environmental and disaster mitigation satellite in China, enhanced vegetation index (EVI showed the best correlation with LAI and was thus used as a proxy for LAI to estimate Rs at the regional scale. The spatial distribution of SOC content was obtained by extrapolating the SOC content at the plot scale based on the kriging interpolation method in GIS. When data were pooled for 38 plots, a first-order exponential analysis indicated that approximately 73% of the spatial variability in Rs during the peak growing season of maize can be explained by EVI and SOC content. Further test analysis based on independent data from 15 plots showed that the simple exponential model had acceptable accuracy in estimating the spatial patterns of Rs in maize fields on the basis of remotely sensed EVI and GIS-interpolated SOC content, with R2 of 0.69 and root-mean-square error of 0.51 µmol CO2 m(-2 s(-1. The conclusions from this study provide valuable information for estimates of Rs during the peak growing season of maize in three counties in North China.

  13. Modeling spatial patterns of soil respiration in maize fields from vegetation and soil property factors with the use of remote sensing and geographical information system.

    Science.gov (United States)

    Huang, Ni; Wang, Li; Guo, Yiqiang; Hao, Pengyu; Niu, Zheng

    2014-01-01

    To examine the method for estimating the spatial patterns of soil respiration (Rs) in agricultural ecosystems using remote sensing and geographical information system (GIS), Rs rates were measured at 53 sites during the peak growing season of maize in three counties in North China. Through Pearson's correlation analysis, leaf area index (LAI), canopy chlorophyll content, aboveground biomass, soil organic carbon (SOC) content, and soil total nitrogen content were selected as the factors that affected spatial variability in Rs during the peak growing season of maize. The use of a structural equation modeling approach revealed that only LAI and SOC content directly affected Rs. Meanwhile, other factors indirectly affected Rs through LAI and SOC content. When three greenness vegetation indices were extracted from an optical image of an environmental and disaster mitigation satellite in China, enhanced vegetation index (EVI) showed the best correlation with LAI and was thus used as a proxy for LAI to estimate Rs at the regional scale. The spatial distribution of SOC content was obtained by extrapolating the SOC content at the plot scale based on the kriging interpolation method in GIS. When data were pooled for 38 plots, a first-order exponential analysis indicated that approximately 73% of the spatial variability in Rs during the peak growing season of maize can be explained by EVI and SOC content. Further test analysis based on independent data from 15 plots showed that the simple exponential model had acceptable accuracy in estimating the spatial patterns of Rs in maize fields on the basis of remotely sensed EVI and GIS-interpolated SOC content, with R2 of 0.69 and root-mean-square error of 0.51 µmol CO2 m(-2) s(-1). The conclusions from this study provide valuable information for estimates of Rs during the peak growing season of maize in three counties in North China.

  14. Wave Dragon

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter; Sørensen, H. C.

    1998-01-01

    This paper concerns with the development of the wave energy converter (WEC) Wave Dragon. This WEC is based on the overtopping principle. An overview of the performed research done concerning the Wave Dragon over the past years is given, and the results of one of the more comprehensive studies......, concerning a hydraulic evaluation and optimisation of the geometry of the Wave Dragon, is presented. Furthermore, the plans for the future development projects are sketched....

  15. Pattern recognition with magnonic holographic memory device

    Energy Technology Data Exchange (ETDEWEB)

    Kozhevnikov, A.; Dudko, G.; Filimonov, Y. [Kotel' nikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, Saratov Branch, Saratov 410019 (Russian Federation); Gertz, F.; Khitun, A. [Electrical Engineering Department, University of California - Riverside, Riverside, California 92521 (United States)

    2015-04-06

    In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed.

  16. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

  17. Wave phenomena

    CERN Document Server

    Towne, Dudley H

    1988-01-01

    This excellent undergraduate-level text emphasizes optics and acoustics, covering inductive derivation of the equation for transverse waves on a string, acoustic plane waves, boundary-value problems, polarization, three-dimensional waves and more. With numerous problems (solutions for about half). ""The material is superbly chosen and brilliantly written"" - Physics Today. Problems. Appendices.

  18. Reduced-order prediction of rogue waves in two-dimensional deep-water waves

    CERN Document Server

    Farazmand, Mohammad

    2016-01-01

    We consider the problem of large wave prediction in two-dimensional water waves. Such waves form due to the synergistic effect of dispersive mixing of smaller wave groups and the action of localized nonlinear wave interactions that leads to focusing. Instead of a direct simulation approach, we rely on the decomposition of the wave field into a discrete set of localized wave groups with optimal length scales and amplitudes. Due to the short-term character of the prediction, these wave groups do not interact and therefore their dynamics can be characterized individually. Using direct numerical simulations of the governing envelope equations we precompute the expected maximum elevation for each of those wave groups. The combination of the wave field decomposition algorithm, which provides information about the statistics of the system, and the precomputed map for the expected wave group elevation, which encodes dynamical information, allows (i) for understanding of how the probability of occurrence of rogue wave...

  19. Gravitational waves from inflation

    Science.gov (United States)

    Guzzetti, M. C.; Bartolo, N.; Liguori, M.; Matarrese, S.

    2016-09-01

    The production of a stochastic background of gravitational waves is a fundamental prediction of any cosmological inflationary model. The features of such a signal encode unique information about the physics of the Early Universe and beyond, thus representing an exciting, powerful window on the origin and evolution of the Universe. We review the main mechanisms of gravitational-wave production, ranging from quantum fluctuations of the gravitational field to other mechanisms that can take place during or after inflation. These include e.g. gravitational waves generated as a consequence of extra particle production during inflation, or during the (p)reheating phase. Gravitational waves produced in inflation scenarios based on modified gravity theories and second-order gravitational waves are also considered. For each analyzed case, the expected power spectrum is given. We discuss the discriminating power among different models, associated with the validity/violation of the standard consistency relation between tensor-to-scalar ratio r and tensor spectral index nT. In light of the prospects for (directly/indirectly) detecting primordial gravitational waves, we give the expected present-day gravitational radiation spectral energy-density, highlighting the main characteristics imprinted by the cosmic thermal history, and we outline the signatures left by gravitational waves on the Cosmic Microwave Background and some imprints in the Large-Scale Structure of the Universe. Finally, current bounds and prospects of detection for inflationary gravitational waves are summarized.

  20. CURVATURE RELATION OF WAVE FRONT AND WAVE CHANGING IN EXTERNAL FIELD

    Institute of Scientific and Technical Information of China (English)

    LIU Shen-quan; SONG Le

    2005-01-01

    The changing of wave structure in excitable media in external field is studied and the curvature relation of wave front is analyzed. Under external stimulus the normal velocity of wave front has linear relation with mean curvature of wave front, plane velocity and external field. The simulation methods have been used to analyze BarEiswirth model with external field and obtain the wave pattern of excitable media contained external stimulus. These theoretical analysis and simulation results are identical with experiments of BZ reaction. So the results here theoretically explain the BZ phenomenon under external field and the simulation results here have rich wave patterns.

  1. Tracking Target and Spiral Waves

    DEFF Research Database (Denmark)

    Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads

    2002-01-01

    A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined...... by the evolutes of the actual spiral or target wave. With the use of Gaussian smoothing, a robust method is developed that permits the identification of targets and spirals foci independently of the wave profile. Examples of an analysis of long image sequences from experiments with the Belousov...

  2. Tracking Target and Spiral Waves

    DEFF Research Database (Denmark)

    Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads;

    2002-01-01

    A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined...... by the evolutes of the actual spiral or target wave. With the use of Gaussian smoothing, a robust method is developed that permits the identification of targets and spirals foci independently of the wave profile. Examples of an analysis of long image sequences from experiments with the Belousov...

  3. The spatial epidemiology of trauma: the potential of geographic information science to organize data and reveal patterns of injury and services.

    Science.gov (United States)

    Schuurman, Nadine; Hameed, S Morad; Fiedler, Robert; Bell, Nathaniel; Simons, Richard K

    2008-10-01

    Despite important advances in the prevention and treatment of trauma, preventable injuries continue to impact the lives of millions of people. Motor vehicle collisions and violence claim close to 3 million lives each year worldwide. Public health agencies have promoted the need for systematic and ongoing surveillance as a foundation for successful injury control. Surveillance has been used to quantify the incidence of injury for the prioritization of further research, monitor trends over time, identify new injury patterns, and plan and evaluate prevention and intervention efforts. Advances in capability to handle spatial data and substantial increases in computing power have positioned geographic information science (GIS) as a potentially important tool for health surveillance and the spatial organization of health care, and for informing prevention and acute care interventions. Two themes emerge in the trauma literature with respect to GIS theory and techniques: identifying determinants associated with the risk of trauma to guide injury prevention efforts and evaluating the spatial organization and accessibility of acute trauma care systems. We review the current literature on trauma and GIS research and provide examples of the importance of accounting for spatial scale when using spatial analysis for surveillance. The examples illustrate the effect of scale on incident analysis, the geographic variation of major injury across British Columbia's health service delivery areas (HSDAs) and the rates of variation of injury within individual HSDAs.

  4. Grid cell firing patterns may arise from feedback interaction between intrinsic rebound spiking and transverse travelling waves with multiple heading angles

    Directory of Open Access Journals (Sweden)

    Michael E Hasselmo

    2014-10-01

    Full Text Available This article presents a model using cellular resonance and rebound properties to model grid cells in medial entorhinal cortex. The model simulates the intrinsic resonance properties of single layer II stellate cells with different frequencies due to the hyperpolarization activated cation current (h current. The stellate cells generate rebound spikes after a delay interval that differs for neurons with different resonance frequency. Stellate cells drive inhibitory interneurons to cause rebound from inhibition in an alternating set of stellate cells that drive interneurons to activate the first set of cells. This allows maintenance of activity with cycle skipping of the spiking of cells that matches recent physiological data on theta cycle skipping. The rebound spiking interacts with subthreshold oscillatory input to stellate cells or interneurons regulated by medial septal input and defined relative to the spatial location coded by neurons. The timing of rebound determines whether the network maintains the activity for the same location or shifts to phases of activity representing a different location. Simulations show that spatial firing patterns similar to grid cells can be generated with a range of different resonance frequencies, indicating how grid cells could be generated with low frequencies present in bats and in mice with knockout of the HCN1 subunit of the h current.

  5. Discriminating non-native vowels on the basis of multimodal, auditory or visual information: effects on infants’ looking patterns and discrimination

    Directory of Open Access Journals (Sweden)

    Sophie eTer Schure

    2016-04-01

    Full Text Available Infants’ perception of speech sound contrasts is modulated by their language environment, for example by the statistical distributions of the speech sounds they hear. Infants learn to discriminate speech sounds better when their input contains a two-peaked frequency distribution of those speech sounds than when their input contains a one-peaked frequency distribution. Effects of frequency distributions on phonetic learning have been tested almost exclusively for auditory input. But auditory speech is usually accompanied by visual information, that is, by visible articulations. This study tested whether infants’ phonological perception is shaped by distributions of visual speech as well as by distributions of auditory speech, by comparing learning from multimodal (i.e. auditory–visual, visual-only, or auditory-only information. Dutch 8-month-old infants were exposed to either a one-peaked or two-peaked distribution from a continuum of vowels that formed a contrast in English, but not in Dutch. We used eye tracking to measure effects of distribution and sensory modality on infants’ discrimination of the contrast. Although there were no overall effects of distribution or modality, separate t-tests in each of the six training conditions demonstrated significant discrimination of the vowel contrast in the two-peaked multimodal condition. For the modalities where the mouth was visible (visual-only and multimodal we further examined infant looking patterns for the dynamic speaker’s face. Infants in the two-peaked multimodal condition looked longer at her mouth than infants in any of the three other conditions. We propose that by eight months, infants’ native vowel categories are established insofar that learning a novel contrast is supported by attention to additional information, such as visual articulations.

  6. Discriminating Non-native Vowels on the Basis of Multimodal, Auditory or Visual Information: Effects on Infants' Looking Patterns and Discrimination.

    Science.gov (United States)

    Ter Schure, Sophie; Junge, Caroline; Boersma, Paul

    2016-01-01

    Infants' perception of speech sound contrasts is modulated by their language environment, for example by the statistical distributions of the speech sounds they hear. Infants learn to discriminate speech sounds better when their input contains a two-peaked frequency distribution of those speech sounds than when their input contains a one-peaked frequency distribution. Effects of frequency distributions on phonetic learning have been tested almost exclusively for auditory input. But auditory speech is usually accompanied by visual information, that is, by visible articulations. This study tested whether infants' phonological perception is shaped by distributions of visual speech as well as by distributions of auditory speech, by comparing learning from multimodal (i.e., auditory-visual), visual-only, or auditory-only information. Dutch 8-month-old infants were exposed to either a one-peaked or two-peaked distribution from a continuum of vowels that formed a contrast in English, but not in Dutch. We used eye tracking to measure effects of distribution and sensory modality on infants' discrimination of the contrast. Although there were no overall effects of distribution or modality, separate t-tests in each of the six training conditions demonstrated significant discrimination of the vowel contrast in the two-peaked multimodal condition. For the modalities where the mouth was visible (visual-only and multimodal) we further examined infant looking patterns for the dynamic speaker's face. Infants in the two-peaked multimodal condition looked longer at her mouth than infants in any of the three other conditions. We propose that by 8 months, infants' native vowel categories are established insofar that learning a novel contrast is supported by attention to additional information, such as visual articulations.

  7. 大数据时代的纳税评估信息采集模式%Pattern of Information Collection for Tax Evaluation in Big Date Era

    Institute of Scientific and Technical Information of China (English)

    何家凤; 何少武

    2015-01-01

    In a time where market participants explodes,we not only combine information fea-tures and needs of the big data,but also innovate the traditional tax assessment information ac-quisition method to adapt to the requirements of the development of taxation informationization. we can innovate tax assessment information acquisition process and management,using unstruc-tured data acquisition,visualization services,data crowdsourcing.Based on the technology of In-ternet of things,we can establish a new elastic frame system to adapt to the tax assessment data massive growth and uncertainty.It is an important way to adapt to the needs of the age of big data information collection,promote the tax source monitoring,improve the efficiency of tax as-sessment,to establish a pattern of information collection for tax evaluation using unified tax appli-cation platform for countries as the center and supported by share data aided system.%面对市场主体数量的爆炸性增长,只有结合大数据时代的信息特征及需求,对传统的纳税评估信息采集模式进行创新才能适应税务信息化发展的要求。通过非结构化数据采集、可视化服务、采集众包模式,创新纳税评估信息采集流程和管理;依托物联网技术,创立适应纳税评估数据海量增长不确定性的弹性构架体系。构建以国家统一税务应用平台为中心,以共享数据辅助系统为支撑的纳税评估信息采集模式,是适应大数据时代信息采集需求,促进税源监控,提高纳税评估效率的重要方式。

  8. Pattern classification

    CERN Document Server

    Duda, Richard O; Stork, David G

    2001-01-01

    The first edition, published in 1973, has become a classic reference in the field. Now with the second edition, readers will find information on key new topics such as neural networks and statistical pattern recognition, the theory of machine learning, and the theory of invariances. Also included are worked examples, comparisons between different methods, extensive graphics, expanded exercises and computer project topics. An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.

  9. The dynamic interplay among maternal empathy, quality of mother-adolescent relationship, and adolescent antisocial behaviors : New insights from a six-wave longitudinal multi-informant study

    NARCIS (Netherlands)

    Crocetti, E.; Moscatelli, S.; van der Graaff, J.; Keijsers, L.G.M.T.; van Lier, P.A.C.; Koot, H.M.; Rubini, M; Meeus, W.H.J.; Branje, S.T.J.

    2016-01-01

    Adolescents’ behavior is often a matter of concern, given their increased likelihood of enacting antisocial behaviors, which cause disruptions in the social order and are potentially harmful for the adolescents themselves and for the people around them. In this six-wave longitudinal study we sought

  10. Periodic folded waves for a (2+1)-dimensional modified dispersive water wave equation

    Institute of Scientific and Technical Information of China (English)

    Huang Wen-Hua

    2009-01-01

    A general solution,including three arbitrary functions,is obtained for a (2+1)-dimensional modified dispersive water-wave (MDWW) equation by means of the WTC truncation method.Introducing proper multiple valued functions and Jacobi elliptic functions in the seed solution,special types of periodic folded waves are derived.In the long wave limit these periodic folded wave patterns may degenerate into single localized folded solitary wave excitations.The interactions of the periodic folded waves and the degenerated single folded solitary waves axe investigated graphically and found to be completely elastic.

  11. Inverse Scattering Approach to Improving Pattern Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Chapline, G; Fu, C

    2005-02-15

    The Helmholtz machine provides what may be the best existing model for how the mammalian brain recognizes patterns. Based on the observation that the ''wake-sleep'' algorithm for training a Helmholtz machine is similar to the problem of finding the potential for a multi-channel Schrodinger equation, we propose that the construction of a Schrodinger potential using inverse scattering methods can serve as a model for how the mammalian brain learns to extract essential information from sensory data. In particular, inverse scattering theory provides a conceptual framework for imagining how one might use EEG and MEG observations of brain-waves together with sensory feedback to improve human learning and pattern recognition. Longer term, implementation of inverse scattering algorithms on a digital or optical computer could be a step towards mimicking the seamless information fusion of the mammalian brain.

  12. Uncertainty in the modelling of spatial and temporal patterns of shallow groundwater flow paths: The role of geological and hydrological site information

    Science.gov (United States)

    Woodward, Simon J. R.; Wöhling, Thomas; Stenger, Roland

    2016-03-01

    Understanding the hydrological and hydrogeochemical responses of hillslopes and other small scale groundwater systems requires mapping the velocity and direction of groundwater flow relative to the controlling subsurface material features. Since point observations of subsurface materials and groundwater head are often the basis for modelling these complex, dynamic, three-dimensional systems, considerable uncertainties are inevitable, but are rarely assessed. This study explored whether piezometric head data measured at high spatial and temporal resolution over six years at a hillslope research site provided sufficient information to determine the flow paths that transfer nitrate leached from the soil zone through the shallow saturated zone into a nearby wetland and stream. Transient groundwater flow paths were modelled using MODFLOW and MODPATH, with spatial patterns of hydraulic conductivity in the three material layers at the site being estimated by regularised pilot point calibration using PEST, constrained by slug test estimates of saturated hydraulic conductivity at several locations. Subsequent Null Space Monte Carlo uncertainty analysis showed that this data was not sufficient to definitively determine the spatial pattern of hydraulic conductivity at the site, although modelled water table dynamics matched the measured heads with acceptable accuracy in space and time. Particle tracking analysis predicted that the saturated flow direction was similar throughout the year as the water table rose and fell, but was not aligned with either the ground surface or subsurface material contours; indeed the subsurface material layers, having relatively similar hydraulic properties, appeared to have little effect on saturated water flow at the site. Flow path uncertainty analysis showed that, while accurate flow path direction or velocity could not be determined on the basis of the available head and slug test data alone, the origin of well water samples relative to the

  13. Wave-driven Countercurrent Plasma Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    A.J. Fetterman and N.J. Fisch

    2009-03-20

    A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the α channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow pattern using waves instead of electrodes, physical and engineering issues may be avoided.

  14. Shear wave speed recovery in sonoelastography using crawling wave data.

    Science.gov (United States)

    Lin, Kui; McLaughlin, Joyce; Renzi, Daniel; Thomas, Ashley

    2010-07-01

    The crawling wave experiment, in which two harmonic sources oscillate at different but nearby frequencies, is a development in sonoelastography that allows real-time imaging of propagating shear wave interference patterns. Previously the crawling wave speed was recovered and used as an indicator of shear stiffness; however, it is shown in this paper that the crawling wave speed image can have artifacts that do not represent a change in stiffness. In this paper, the locations and shapes of some of the artifacts are exhibited. In addition, a differential equation is established that enables imaging of the shear wave speed, which is a quantity strongly correlated with shear stiffness change. The full algorithm is as follows: (1) extract the crawling wave phase from the spectral variance data; (2) calculate the crawling wave phase wave speed; (3) solve a first-order PDE for the phase of the wave emanating from one of the sources; and (4) compute and image the shear wave speed on a grid in the image plane.

  15. Pattern Recognition-Assisted Infrared Library Searching of the Paint Data Query Database to Enhance Lead Information from Automotive Paint Trace Evidence.

    Science.gov (United States)

    Lavine, Barry K; White, Collin G; Allen, Matthew D; Weakley, Andrew

    2017-03-01

    Multilayered automotive paint fragments, which are one of the most complex materials encountered in the forensic science laboratory, provide crucial links in criminal investigations and prosecutions. To determine the origin of these paint fragments, forensic automotive paint examiners have turned to the paint data query (PDQ) database, which allows the forensic examiner to compare the layer sequence and color, texture, and composition of the sample to paint systems of the original equipment manufacturer (OEM). However, modern automotive paints have a thin color coat and this layer on a microscopic fragment is often too thin to obtain accurate chemical and topcoat color information. A search engine has been developed for the infrared (IR) spectral libraries of the PDQ database in an effort to improve discrimination capability and permit quantification of discrimination power for OEM automotive paint comparisons. The similarity of IR spectra of the corresponding layers of various records for original finishes in the PDQ database often results in poor discrimination using commercial library search algorithms. A pattern recognition approach employing pre-filters and a cross-correlation library search algorithm that performs both a forward and backward search has been used to significantly improve the discrimination of IR spectra in the PDQ database and thus improve the accuracy of the search. This improvement permits inter-comparison of OEM automotive paint layer systems using the IR spectra alone. Such information can serve to quantify the discrimination power of the original automotive paint encountered in casework and further efforts to succinctly communicate trace evidence to the courts.

  16. Making waves

    Science.gov (United States)

    Kruse, Karsten

    2017-01-01

    Traveling waves propagating along surfaces play an important role for intracellular organization. Such waves can appear spontaneously in reaction-diffusion systems, but only few general criteria for their existence are known. Analyzing the dynamics of the Min proteins in Escherichia coli, Levine and Kessler (2016 New J. Phys. 18 122001) now identified a new mechanism for the emergence of traveling waves that relies on conservation laws. From their analysis one can expect traveling waves to be a generic feature of systems made of proteins that have a cytoplasmic and a membrane-bound state.

  17. Janus Waves

    OpenAIRE

    2016-01-01

    We show the existence of a family of waves that share a common interesting property affecting the way they propagate and focus. These waves are a superposition of twin waves, which are conjugate to each other under inversion of the propagation direction. In analogy to holography, these twin "real" and "virtual" waves are related respectively to the converging and the diverging part of the beam and can be clearly visualized in real space at two distinct foci under the action of a focusing lens...

  18. Wave phenomena in sunspots

    Science.gov (United States)

    Löhner-Böttcher, Johannes

    2016-03-01

    magnetic field lines. Signatures of umbral flashes and running penumbral waves are found already in the middle to upper photosphere. The signal and velocity increases toward the chromosphere. The shock wave behavior of the umbral flashes is confirmed by the evolving saw-tooth pattern in velocity and the strong downward motion of the plasma right after the passage of the shock front. The power spectra and peak periods of sunspot waves vary significantly with atmospheric altitude and position within the sunspot. In the vertical field of the umbra, the mixture of wave periods in the lower photosphere transforms into a domination of the 2.5min range in the upper photosphere and chromosphere. In the differentially inclined penumbra, the dominating wave periods increase with radial distance. The acoustic cut-off frequency which blocks the propagation of long-period waves is considered to increase with the field inclination and the ambient sound speed. The reconstruction of the sunspot's magnetic field inclination based on the peak period distribution yields consistent results with the inferred photospheric and extrapolated coronal magnetic field.

  19. Tailored sensitivity reduction improves pattern recognition and information recovery with a higher tolerance to varied sample concentration for targeted urinary metabolomics.

    Science.gov (United States)

    Yan, Zhixiang; Yan, Ru

    2016-04-22

    Variation in total metabolite concentration among different samples has been a major challenge for urinary metabolomics. Here we investigated the potential of tailored sensitivity reduction of high abundance metabolites for improved targeted urinary metabolomics. Two levels of sensitivity reduction of the 21 predominant urinary metabolites were assessed by employing less sensitive transition or collision energy with level 1 (reduced 1) and 2 (reduced 2) exhibiting 30-90% and 2-20% of the optimal sensitivity, respectively. Five postacquisition normalization methods were compared including no normalization, probabilistic quotient normalization, and normalization to sample median, creatinine intensity, and total intensity. Normalization to total intensity with reduced 2 gave the best pattern recognition and information recovery with a higher tolerance to varied sample concentration. Pareto scaling could improve the performance of tailored sensitivity reduction (reduced 2) for targeted urinary metabolomics while data transformation and autoscaling were susceptible to varied sample concentration. Using controlled spike-in experiments, we demonstrated that tailored sensitivity reduction revealed more differentially expressed markers with higher accuracy than did the conventional optimal sensitivity. This was particularly true when the differences between the sample groups are small. This work also served as an introductory guideline for handling targeted metabolomics data using the open-source software MetaboAnalyst.

  20. Wave Height Distribution for Spilling Waves in and outside the Surf Zone

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The wave characteristics affecting coastal sediment transport include wave height, wave period and breaking wave direction. Wave height is a critical factor in determining the amount of sediment transport in the coastal area. The force of sediment transport is much more intense under breaking waves than under non-breaking waves. Breaking waves exhibit various patterns, principally depending on the incident wave steepness and the beach slope. Based on the equations of conservation of mass, momentum and energy, a theoretical model for wave deformation in and outside the surf zone was obtained, which is used to calculate the wave shoaling, wave set-up and setdown and wave height distributions in and outside the surf zone. The analysis and comparison were made about the breaking point location and the wave height decay caused by the wave breaking and the bottom friction. Flume experiments relating to the spilling wave height distribution across the surf zone were conducted to verify the theoretical model. Advanced wave maker, data sampling devices and data processing system were utilized in the flume experiments with a slope covered by sands of different diameters to facilitate the observation and research on the wave transformation and breaking. The agreement between the theoretical and experimental results is good.

  1. Wave climate projections using statistical downscaling for the Gold Coast (Australia)

    Science.gov (United States)

    Rueda, Ana; Camus, Paula; Méndez, Fernando; Sano, Marcello; Strauss, Darrel; Hemer, Mark

    2013-04-01

    Projections of future wave climate at the regional level are essential to develop climate change adaptation strategies for coastal areas. In our research we looked at wave climate projections along the Gold Coast, with a detailed assessment for Palm Beach, one of the most problematic coastal stretches. We adopted a statistical downscaling approach which is based on the statistical relationship between a local wave variable (predictand) and a global atmospheric variable (predictor). This is an efficient method to project regional wave climate based on the output of General Circulation Models (GCMs) forced by different emission scenarios, the main source of information of possible future climates. The methodology used relies on data availability for the area of study. In this case we used sea level pressure fields from 1 h x 0.5° resolution CFSR reanalysis to define the predictor. A CSIRO 1° spatial resolution wave hindcast was chosen to define the predictand; this was particularly reliable due to its long-term directional spectral information. A hybrid methodology was used before statistical downscaling to transfer wave climate to the study area as the CSIRO wave reanalysis was not available at high resolution in shallow water. In our method, the predictor is defined by the dynamical spatial patterns of atmospheric conditions considering the local area and the wave generation area in order to take into account the swell and sea wave components. A daily atmospheric field database is developed and classified in circulation patterns (weather types) using PCA and the k-means algorithm. The corresponding predictand are the sea states at the coastal area (Hs, Tm, ? and directional spectra). The total wave distribution at the target point can be reconstructed from the distribution of sea states and its corresponding probability of each weather type. This method allows estimating how local wave climate can be affected by changes on the atmospheric patterns, calculating

  2. ON SOURCE ANALYSIS BY WAVE SPLITTING WITH APPLICATIONS IN INVERSE SCATTERING OF MULTIPLE OBSTACLES

    Institute of Scientific and Technical Information of China (English)

    Fahmi ben Hassen; Jijun Liu; Roland Potthast

    2007-01-01

    We study wave splitting procedures for acoustic or electromagnetic scattering problems. The idea of these procedures is to split some scattered field into a sum of fields coming from different spatial regions such that this information can be used either for inversion algorithms or for active noise control. Splitting algorithms can be based on general boundary layer potential representation or Green's representation formula. We will prove the unique decomposition of scattered wave outside the specified reference domain G and the unique decomposition of far-field pattern with respect to different reference domain G. Further, we employ the splitting technique for field reconstruction for a scatterer with two or more separate components, by combining it with the point source method for wave recovery. Using the decomposition of scattered wave as well as its far-field pattern, the wave splitting procedure proposed in this paper gives an efficient way to the computation of scattered wave near the obstacle, from which the multiple obstacles which cause the far-field pattern can be reconstructed separately. This considerably extends the range of the decomposition methods in the area of inverse scattering. Finally, we will provide numerical examples to demonstrate the feasibility of the splitting method.

  3. Numerical study of airflow over breaking waves

    Science.gov (United States)

    Yang, Zixuan; Shen, Lian

    2016-11-01

    We present direct numerical simulation (DNS) results on airflow over breaking waves. Air and water are simulated as a coherent system. The initial condition for the simulation is a fully-developed turbulent airflow over strongly-forced steep waves. The airflow is driven by a shear stress at the top. The effects of the initial wave steepness and wave age are studied systematically. Because wave breaking is an unsteady process, we use ensemble averaging of a large number of runs to obtain turbulent statistics. Simulation results show that the airflow above does not see the wave trough during wave breaking. Vortex structures at different stages of wave breaking are analyzed based on a linear stochastic estimation method. It is found that the wave breaking alters the pattern of vortex structures.

  4. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Friis-Madsen, Erik

    2008-01-01

    Since March 2003 a prototype of Wave Dragon has been tested in an inland sea in Denmark. This has been a great success with all subsystems tested and improved through working in an offshore environment. The project has proved the Wave Dragon device and has enabled the next stage, a production sized...

  5. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Friis-Madsen, Erik;

    2008-01-01

    Since March 2003 a prototype of Wave Dragon has been tested in an inland sea in Denmark. This has been a great success with all subsystems tested and improved through working in an offshore environment. The project has proved the Wave Dragon device and has enabled the next stage, a production sized...

  6. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star.......Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star....

  7. Sand Wave Migrations Within Monterey Submarine Canyon, California

    Science.gov (United States)

    Xu, J.; Wong, F. L.

    2006-12-01

    Repeated high-resolution multi-beam surveys revealed the existence of a sand wave field along the axis of the Monterey submarine canyon between 20 and 300 m water depth. These sand waves range in wave length from 20 to 70 m and 2 to 5 m in height. Comparison of sequential multi-beam grid data (months apart) indicates that the sand waves apparently migrate upcanyon at some places while the same data clearly show that the sand waves migrate downcanyon at other locations. One hypothesis is that strong internal tidal flows, whose upcanyon component is intensified by the narrow canyon, are responsible for forming the sand wave field and for migrating the sand waves upcanyon. Another hypothesis is that the sand wave field is formed by creeping (analogous to the movement within glaciers), and in general they move in the downcanyon direction. A field experiment was conducted in 2005-06 to measure the driving forces (in hypothesis #1) that form and move the sand waves, and to collect the internal sedimentological structure within the sand waves that could reveal information on hypothesis #2. A mooring designed to measure near-floor velocity profiles, temperature, salinity, and sediment concentration in the water column was deployed for one year (June 2005 -July 2006) at 250 m water depth, slightly downcanyon of the sand wave field. In addition, a mapping survey was conducted in February, 2006 for collecting multi-beam and chirp profiles in the canyon head area of the sand wave field. Preliminary examination of the ADCP (downward looking) showed some very interesting features - the near- floor current dramatically changes with the spring-neap cycle of the surface tide. The time variation of the along-canyon current during neap tides - a sudden jump of upcanyon velocity before gradually tapering down, is typical of internal tides (internal bores). The time variation during spring tides when along canyon velocities reverse directions from upcanyon to downcanyon and gradually

  8. Wave Solutions

    CERN Document Server

    Christov, Ivan C

    2012-01-01

    In classical continuum physics, a wave is a mechanical disturbance. Whether the disturbance is stationary or traveling and whether it is caused by the motion of atoms and molecules or the vibration of a lattice structure, a wave can be understood as a specific type of solution of an appropriate mathematical equation modeling the underlying physics. Typical models consist of partial differential equations that exhibit certain general properties, e.g., hyperbolicity. This, in turn, leads to the possibility of wave solutions. Various analytical techniques (integral transforms, complex variables, reduction to ordinary differential equations, etc.) are available to find wave solutions of linear partial differential equations. Furthermore, linear hyperbolic equations with higher-order derivatives provide the mathematical underpinning of the phenomenon of dispersion, i.e., the dependence of a wave's phase speed on its wavenumber. For systems of nonlinear first-order hyperbolic equations, there also exists a general ...

  9. Reconstructing the Work Pattern of Modern Information Analysis with Knowledge Management%利用知识管理重构现代情报研究工作模式

    Institute of Scientific and Technical Information of China (English)

    刘勇; 周倩

    2003-01-01

    As a brand-new kind of management thought and management mode, the successful application of knowledge management in numerous fields has aroused much concern and discussion in the society. This article aims to find out the effective methods and feasible measures to utilize knowledge management to reconstruct the work pattern of modem information analysis by analyzing and studying the influence of knowledge management on modem information analysis.

  10. Waves, damped wave and observation

    CERN Document Server

    Phung, Kim Dang

    2009-01-01

    We consider the wave equation in a bounded domain (eventually convex). Two kinds of inequality are described when occurs trapped ray. Applications to control theory are given. First, we link such kind of estimate with the damped wave equation and its decay rate. Next, we describe the design of an approximate control function by an iterative time reversal method.

  11. Electromagnetic waves in stratified media

    CERN Document Server

    Wait, James R; Fock, V A; Wait, J R

    2013-01-01

    International Series of Monographs in Electromagnetic Waves, Volume 3: Electromagnetic Waves in Stratified Media provides information pertinent to the electromagnetic waves in media whose properties differ in one particular direction. This book discusses the important feature of the waves that enables communications at global distances. Organized into 13 chapters, this volume begins with an overview of the general analysis for the electromagnetic response of a plane stratified medium comprising of any number of parallel homogeneous layers. This text then explains the reflection of electromagne

  12. Gravity waves

    Science.gov (United States)

    Fritts, David

    1987-02-01

    Gravity waves contributed to the establishment of the thermal structure, small scale (80 to 100 km) fluctuations in velocity (50 to 80 m/sec) and density (20 to 30%, 0 to peak). Dominant gravity wave spectrum in the middle atmosphere: x-scale, less than 100 km; z-scale, greater than 10 km; t-scale, less than 2 hr. Theorists are beginning to understand middle atmosphere motions. There are two classes: Planetary waves and equatorial motions, gravity waves and tidal motions. The former give rise to variability at large scales, which may alter apparent mean structure. Effects include density and velocity fluctuations, induced mean motions, and stratospheric warmings which lead to the breakup of the polar vortex and cooling of the mesosphere. On this scale are also equatorial quasi-biennial and semi-annual oscillations. Gravity wave and tidal motions produce large rms fluctuations in density and velocity. The magnitude of the density fluctuations compared to the mean density is of the order of the vertical wavelength, which grows with height. Relative density fluctuations are less than, or of the order of 30% below the mesopause. Such motions may cause significant and variable convection, and wind shear. There is a strong seasonal variation in gravity wave amplitude. Additional observations are needed to address and quantify mean and fluctuation statistics of both density and mean velocity, variability of the mean and fluctuations, and to identify dominant gravity wave scales and sources as well as causes of variability, both temporal and geographic.

  13. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Knapp, W.

    2006-01-01

    Wave Dragon is a floating wave energy converter working by extracting energy principally by means of overtopping of waves into a reservoir. A 1:4.5 scale prototype has been sea tested for 20 months. This paper presents results from testing, experiences gained and developments made during...... this extended period. The prototype is highly instrumented. The overtopping characteristic and the power produced are presented here. This has enabled comparison between the prototype and earlier results from both laboratory model and computer simulation. This gives the optimal operating point and the expected...

  14. Aircraft measurements of wave cloud

    Directory of Open Access Journals (Sweden)

    Z. Cui

    2012-05-01

    Full Text Available In this paper, aircraft measurements are presented of liquid phase (ice-free wave clouds made at temperatures greater than −5 °C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. A new definition of a mountain-wave cloud is given, based on the measurements presented here and previous studies. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and clouds.

  15. Self-concept clarity in adolescents and parents: A six-wave longitudinal and multi-Informant study on development and intergenerational transmission.

    NARCIS (Netherlands)

    Crocetti, E; Rubini, M; Branje, S; Koot, H; Meeus, W.H.J.

    2016-01-01

    The purpose of this study was twofold: (a) to disentangle patterns of change and stability in self-concept clarity (SCC) in adolescents and in their parents and (b) to examine processes of intergenerational transmission of SCC in families with adolescents. Participants were 497 Dutch families

  16. Earthquake Source Parameters Inferred from T-Wave Observations

    Science.gov (United States)

    Perrot, J.; Dziak, R.; Lau, T. A.; Matsumoto, H.; Goslin, J.

    2004-12-01

    The seismicity of the North Atlantic Ocean has been recorded by two networks of autonomous hydrophones moored within the SOFAR channel on the flanks of the Mid-Atlantic Ridge (MAR). In February 1999, a consortium of U.S. investigators (NSF and NOAA) deployed a 6-element hydrophone array for long-term monitoring of MAR seismicity between 15o-35oN south of the Azores. In May 2002, an international collaboration of French, Portuguese, and U.S. researchers deployed a 6-element hydrophone array north of the Azores Plateau from 40o-50oN. The northern network (referred to as SIRENA) was recovered in September 2003. The low attenuation properties of the SOFAR channel for earthquake T-wave propagation results in a detection threshold reduction from a magnitude completeness level (Mc) of ˜ 4.7 for MAR events recorded by the land-based seismic networks to Mc=3.0 using hydrophone arrays. Detailed focal depth and mechanism information, however, remain elusive due to the complexities of seismo-acoustic propagation paths. Nonetheless, recent analyses (Dziak, 2001; Park and Odom, 2001) indicate fault parameter information is contained within the T-wave signal packet. We investigate this relationship further by comparing an earthquake's T-wave duration and acoustic energy to seismic magnitude (NEIC) and radiation pattern (for events M>5) from the Harvard moment-tensor catalog. First results show earthquake energy is well represented by the acoustic energy of the T-waves, however T-wave codas are significantly influenced by acoustic propagation effects and do not allow a direct determination of the seismic magnitude of the earthquakes. Second, there appears to be a correlation between T-wave acoustic energy, azimuth from earthquake source to the hydrophone, and the radiation pattern of the earthquake's SH waves. These preliminary results indicate there is a relationship between the T-wave observations and earthquake source parameters, allowing for additional insights into T-wave

  17. Assimilation of Wave Imaging Radar Observations for Real-time Wave-by-Wave Forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Alexandra [Oregon State Univ., Corvallis, OR (United States); Haller, Merrick; Walker, David [SRI International, Menlo Park, CA (United States); Lynett, Pat [Univ. of Southern California, Los Angeles, CA (United States)

    2017-08-29

    forecasting in real-time, as the GPU-based wave model backbone was very computationally efficient. The data assimilation algorithm was developed on a polar grid domain in order to match the sampling characteristics of the observation system (wave imaging marine radar). For verification purposes, a substantial set of synthetic wave data (i.e. forward runs of the wave model) were generated to be used as ground truth for comparison to the reconstructions and forecasts produced by Wavecast. For these synthetic cases, Wavecast demonstrated very good accuracy, for example, typical forecast correlation coefficients were between 0.84-0.95 when compared to the input data. Dependencies on shadowing, observational noise, and forecast horizon were also identified. During the second year of the project, a short field deployment was conducted in order to assess forecast accuracy under field conditions. For this, a radar was installed on a fishing vessel and observations were collected at the South Energy Test Site (SETS) off the coast of Newport, OR. At the SETS site, simultaneous in situ wave observations were also available owing to an ongoing field project funded separately. Unfortunately, the position and heading information that was available for the fishing vessel were not of sufficient accuracy in order to validate the forecast in a phase-resolving sense. Instead, a spectral comparison was made between the Wavecast forecast and the data from the in situ wave buoy. Although the wave and wind conditions during the field test were complex, the comparison showed a promising reconstruction of the wave spectral shape, where both peaks in the bimodal spectrum were represented. However, the total reconstructed spectral energy (across all directions and frequencies) was limited to 44% of the observed spectrum. Overall, wave-by-wave forecasting using a data assimilation approach based on wave imaging radar observations and a physics-based wave model shows promise for short-term phase

  18. Spike-like solitary waves in incompressible boundary layers driven by a travelling wave.

    Science.gov (United States)

    Feng, Peihua; Zhang, Jiazhong; Wang, Wei

    2016-06-01

    Nonlinear waves produced in an incompressible boundary layer driven by a travelling wave are investigated, with damping considered as well. As one of the typical nonlinear waves, the spike-like wave is governed by the driven-damped Benjamin-Ono equation. The wave field enters a completely irregular state beyond a critical time, increasing the amplitude of the driving wave continuously. On the other hand, the number of spikes of solitary waves increases through multiplication of the wave pattern. The wave energy grows in a sequence of sharp steps, and hysteresis loops are found in the system. The wave energy jumps to different levels with multiplication of the wave, which is described by winding number bifurcation of phase trajectories. Also, the phenomenon of multiplication and hysteresis steps is found when varying the speed of driving wave as well. Moreover, the nature of the change of wave pattern and its energy is the stability loss of the wave caused by saddle-node bifurcation.

  19. Tapping of Love waves in an isotropic surface waveguide by surface-to-bulk wave transduction.

    Science.gov (United States)

    Tuan, H.-S.; Chang, C.-P.

    1972-01-01

    A theoretical study of tapping a Love wave in an isotropic microacoustic surface waveguide is given. The surface Love wave is tapped by partial transduction into a bulk wave at a discontinuity. It is shown that, by careful design of the discontinuity, the converted bulk wave power and the radiation pattern may be controlled. General formulas are derived for the calculation of these important characteristics from a relatively general surface contour deformation.

  20. Interference of diffusive light waves.

    Science.gov (United States)

    Schmitt, J M; Knüttel, A; Knutson, J R

    1992-10-01

    We examine interference effects resulting from the superposition of photon-density waves produced by coherently modulated light incident upon a turbid medium. Photon-diffusion theory is used to derive expressions for the ac magnitude and phase of the aggregate diffusive wave produced in full- and half-space volumes by two sources. Using a frequency-domain spectrometer operating at 410 MHz, we verify interference patterns predicted by the model in scattering samples having optical properties similar to those of skin tissue. Potential imaging applications of interfering diffusive waves are discussed in the context of the theoretical and experimental results.

  1. Popsicle-Stick Cobra Wave

    Science.gov (United States)

    Boucher, Jean-Philippe; Clanet, Christophe; Quéré, David; Chevy, Frédéric

    2017-08-01

    The cobra wave is a popular physical phenomenon arising from the explosion of a metastable grillage made of popsicle sticks. The sticks are expelled from the mesh by releasing the elastic energy stored during the weaving of the structure. Here we analyze both experimentally and theoretically the propagation of the wave front depending on the properties of the sticks and the pattern of the mesh. We show that its velocity and its shape are directly related to the recoil imparted to the structure by the expelled sticks. Finally, we show that the cobra wave can only exist for a narrow range of parameters constrained by gravity and rupture of the sticks.

  2. Wave Instability and Spatiotemporal Chaos in Reaction-Diffusion System with Oscillatory Dynamics

    Institute of Scientific and Technical Information of China (English)

    XIE Fa-Gen; YANG Jun-Zhong; LI Hong-Gang

    2006-01-01

    We investigate the Turing-like wave instability of the uniform oscillator in oscillatory mediums using theoretical and numerical methods. A propagating wave pattern originated at the corner of the system emerges when the uniform oscillator becomes unstable via Turing-like wave instability. Bifurcations from periodically propagated wave patterns to quasi-periodically propagated wave patterns, then to spatiotemporal chaos occur, as the system size increases from the instability threshold of the uniform oscillator.

  3. Janus Waves

    CERN Document Server

    Papazoglou, Dimitris G; Tzortzakis, Stelios

    2016-01-01

    We show the existence of a family of waves that share a common interesting property affecting the way they propagate and focus. These waves are a superposition of twin waves, which are conjugate to each other under inversion of the propagation direction. In analogy to holography, these twin "real" and "virtual" waves are related respectively to the converging and the diverging part of the beam and can be clearly visualized in real space at two distinct foci under the action of a focusing lens. Analytic formulas for the intensity distribution after focusing are derived, while numerical and experimental demonstrations are given for some of the most interesting members of this family, the accelerating Airy and ring-Airy beams.

  4. Measuring sea surface height with a GNSS-Wave Glider

    Science.gov (United States)

    Morales Maqueda, Miguel Angel; Penna, Nigel T.; Foden, Peter R.; Martin, Ian; Cipollini, Paolo; Williams, Simon D.; Pugh, Jeff P.

    2017-04-01

    A GNSS-Wave Glider is a novel technique to measure sea surface height autonomously using the Global Navigation Satellite System (GNSS). It consists of an unmanned surface vehicle manufactured by Liquid Robotics, a Wave Glider, and a geodetic-grade GNSS antenna-receiver system, with the antenna installed on a mast on the vehicle's deck. The Wave Glider uses the differential wave motion through the water column for propulsion, thus guaranteeing an, in principle, indefinite autonomy. Solar energy is collected to power all on-board instrumentation, including the GNSS system. The GNSS-Wave Glider was first tested in Loch Ness in 2013, demonstrating that the technology is capable of mapping geoid heights within the loch with an accuracy of a few centimetres. The trial in Loch Ness did not conclusively confirm the reliability of the technique because, during the tests, the state of the water surface was much more benign than would normally be expect in the open ocean. We now report on a first deployment of a GNSS-Wave Glider in the North Sea. The deployment took place in August 2016 and lasted thirteen days, during which the vehicle covered a distance of about 350 nautical miles in the north western North Sea off Great Britain. During the experiment, the GNSS-Wave Glider experienced sea states between 1 (0-0.1 m wave heights) and 5 (2.5-4 m wave heights). The GNSS-Wave Glider data, recorded at 5 Hz frequency, were analysed using a post-processed kinematic GPS-GLONASS precise point positioning (PPP) approach, which were quality controlled using double difference GPS kinematic processing with respect to onshore reference stations. Filtered with a 900 s moving-average window, the PPP heights reveal geoid patterns in the survey area that are very similar to the EGM2008 geoid model, thus demonstrating the potential use of a GNSS-Wave Glider for marine geoid determination. The residual of subtracting the modelled or measured marine geoid from the PPP signal combines information

  5. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star....

  6. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Andersen, Thomas Lykke

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star....

  7. Secondary microseism generation mechanisms and microseism derived ocean wave parameters, NE Atlantic, West of Ireland.

    Science.gov (United States)

    Donne, S. E.; Bean, C. J.; Lokmer, I.; Nicolau, M.; O'Neill, M.

    2014-12-01

    Ocean waves, driven by atmospheric processes, generate faint continuous Earth vibrations known as microseisms (Bromirski, 1999). Under certain conditions, ocean waves travelling in opposite directions may interact with one another producing a partial or full standing wave. This wave-wave interaction produces a pressure profile, unattenuated with depth, which exerts a pressure change at the seafloor, resulting in secondary microseisms in the 0.1-0.33 Hz band. There are clear correlations between microseism amplitude and storm and ocean wave intensity. We aim to determine ocean wave heights in the Northeast Atlantic offshore Ireland at individual buoy locations, using terrestrially recorded microseism signals. Two evolutionary approaches are used: Artificial Neural Networks (ANN) and Grammatical Evolution (GE). These systems learn to interpret particular input patterns and corresponding outputs and expose the often complex underlying relationship between them. They learn by example and are therefore entirely data driven so data selection is extremely important for the success of the methods. An analysis and comparison of the performance of these methods for a five month period in 2013 will be presented showing that ocean wave characteristics may be reconstructed using microseism amplitudes, adopting a purely data driven approach. There are periods during the year when the estimations made from both the GE and ANN are delayed in time by 10 to 20 hours when compared to the target buoy measurements. These delays hold important information about the totality of the conditions needed for microseism generation, an analysis of which will be presented.

  8. Faraday wave lattice as an elastic metamaterial.

    Science.gov (United States)

    Domino, L; Tarpin, M; Patinet, S; Eddi, A

    2016-05-01

    Metamaterials enable the emergence of novel physical properties due to the existence of an underlying subwavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

  9. Faraday wave lattice as an elastic metamaterial

    CERN Document Server

    Domino, L; Patinet, Sylvain; Eddi, A

    2016-01-01

    Metamaterials enable the emergence of novel physical properties due to the existence of an underlying sub-wavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

  10. Stimulus-entrained oscillatory activity propagates as waves from area 18 to 17 in cat visual cortex.

    Directory of Open Access Journals (Sweden)

    Lian Zheng

    Full Text Available Previous studies in cat visual cortex reported that area 18 can actively drive neurons in area 17 through cortico-cortical projections. However, the dynamics of such cortico-cortical interaction remains unclear. Here we used multielectrode arrays to examine the spatiotemporal pattern of neuronal activity in cat visual cortex across the 17/18 border. We found that full-field contrast reversal gratings evoked oscillatory wave activity propagating from area 18 to 17. The wave direction was independent of the grating orientation, and could not be accounted for by the spatial distribution of receptive field latencies, suggesting that the waves are largely mediated by intrinsic connections in the cortex. Different from the evoked waves, spontaneous waves propagated along both directions across the 17/18 border. Together, our results suggest that visual stimulation may enhance the flow of information from area 18 to 17.

  11. Blast Waves

    CERN Document Server

    Needham, Charles E

    2010-01-01

    The primary purpose of this text is to document many of the lessons that have been learned during the author’s more than forty years in the field of blast and shock. The writing therefore takes on an historical perspective, in some sense, because it follows the author’s experience. The book deals with blast waves propagating in fluids or materials that can be treated as fluids. It begins by distinguishing between blast waves and the more general category of shock waves. It then examines several ways of generating blast waves, considering the propagation of blast waves in one, two and three dimensions as well as through the real atmosphere. One section treats the propagation of shocks in layered gases in a more detailed manner. The book also details the interaction of shock waves with structures in particular reflections, progressing from simple to complex geometries, including planar structures, two-dimensional structures such as ramps or wedges, reflections from heights of burst, and three-dimensional st...

  12. Wind wave source functions in opposing seas

    KAUST Repository

    Langodan, Sabique

    2015-08-26

    The Red Sea is a challenge for wave modeling because of its unique two opposed wave systems, forced by opposite winds and converging at its center. We investigate the different physical aspects of wave evolution and propagation in the convergence zone. The two opposing wave systems have similar amplitude and frequency, each driven by the action of its own wind. Wave patterns at the centre of the Red Sea, as derived from extensive tests and intercomparison between model and measured data, suggest that the currently available wave model source functions may not properly represent the evolution of the local fields that appear to be characterized by a less effective wind input and an enhanced white-capping. We propose and test a possible simple solution to improve the wave-model simulation under opposing winds and waves condition. This article is protected by copyright. All rights reserved.

  13. A laboratory study of breaking waves

    Directory of Open Access Journals (Sweden)

    Jaros³aw Têgowski

    2004-09-01

    Full Text Available This paper deals with some aspects of the wave-breaking phenomenon. The objectives were to study wave-breaking criteria, and the probability of whitecap coverage under fully controlled wave conditions. An additional task was to in vestigate the characteristic spectral features of the noise produced by breaking waves and the acoustic energy generated during wave breaking events. A controlled experiment was carried out in the Ocean Basin Laboratory at MARINTEK, Trondheim (Norway. Waves were generated by a computer-controlled multi-flap wave maker, which reproduced a realistic pattern of the sea surface for the prescribed spectra. Using wave staff recordings and photographic techniques, correlations between the breaking parameters and the radiated acoustic emissions were established.

  14. Reduced-order prediction of rogue waves in two-dimensional deep-water waves

    Science.gov (United States)

    Farazmand, Mohammad; Sapsis, Themistoklis P.

    2017-07-01

    We consider the problem of large wave prediction in two-dimensional water waves. Such waves form due to the synergistic effect of dispersive mixing of smaller wave groups and the action of localized nonlinear wave interactions that leads to focusing. Instead of a direct simulation approach, we rely on the decomposition of the wave field into a discrete set of localized wave groups with optimal length scales and amplitudes. Due to the short-term character of the prediction, these wave groups do not interact and therefore their dynamics can be characterized individually. Using direct numerical simulations of the governing envelope equations we precompute the expected maximum elevation for each of those wave groups. The combination of the wave field decomposition algorithm, which provides information about the statistics of the system, and the precomputed map for the expected wave group elevation, which encodes dynamical information, allows (i) for understanding of how the probability of occurrence of rogue waves changes as the spectrum parameters vary, (ii) the computation of a critical length scale characterizing wave groups with high probability of evolving to rogue waves, and (iii) the formulation of a robust and parsimonious reduced-order prediction scheme for large waves. We assess the validity of this scheme in several cases of ocean wave spectra.

  15. Wave diffraction by a cosmic string

    CERN Document Server

    Fernández-Núñez, Isabel

    2016-01-01

    We show that if a cosmic string exists, it may be identified through characteristic diffraction pattern in the energy spectrum of the observed signal. In particular, if the string is on the line of sight, the wave field is shown to fit the Cornu spiral. We suggest a simple procedure, based on Keller's geometrical theory of diffraction, which allows to explain wave effects in conical spacetime of a cosmic string in terms of interference of four characteristic rays. Our results are supposed to be valid for scalar massless waves, including gravitational waves, electromagnetic waves, or even sound in case of condensed matter systems with analogous topological defects.

  16. Wave diffraction by a cosmic string

    Science.gov (United States)

    Fernández-Núñez, Isabel; Bulashenko, Oleg

    2016-08-01

    We show that if a cosmic string exists, it may be identified through characteristic diffraction pattern in the energy spectrum of the observed signal. In particular, if the string is on the line of sight, the wave field is shown to fit the Cornu spiral. We suggest a simple procedure, based on Keller's geometrical theory of diffraction, which allows to explain wave effects in conical spacetime of a cosmic string in terms of interference of four characteristic rays. Our results are supposed to be valid for scalar massless waves, including gravitational waves, electromagnetic waves, or even sound in case of condensed matter systems with analogous topological defects.

  17. Wave Generation Theory

    DEFF Research Database (Denmark)

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered....

  18. Wave Generation Theory

    OpenAIRE

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    1993-01-01

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered.

  19. Analysis on System Operation Information Flowing Pattern Based on Multi-value Objective%基于多元价值目标的体系作战信息流转模式探析

    Institute of Scientific and Technical Information of China (English)

    杨迎辉; 李建华; 南明莉

    2015-01-01

    Efficient and reasonable information flowing pattern is the precondition and important guarantee for system operation based on information system. In this article,value objective theory is introduced,concepts of information flowing are solved. Value objectives and function mechanisms are analyzed,four system operation information flowing patterns based on the maximum information flux, best information quality,minimum transmission time and integrative value objective are provided separately and detailed information flowing strategies are given correspondingly.%高效合理的信息流转模式是有效实施基于信息系统体系作战的前提和重要保障。引入了价值目标理论,解析了信息流转概念内涵,分析了信息流转价值目标与作用机理,分别提出了基于最大信息流量、最佳信息质量、最小传输时间和综合价值目标的体系作战信息流转模式,并给出了信息流转策略。

  20. Nonlinear wave-wave interactions and wedge waves

    Institute of Scientific and Technical Information of China (English)

    Ray Q.Lin; Will Perrie

    2005-01-01

    A tetrad mechanism for exciting long waves,for example edge waves,is described based on nonlinear resonant wave-wave interactions.In this mechanism,resonant interactions pass energy to an edge wave,from the three participating gravity waves.The estimated action flux into the edge wave can be orders of magnitude greater than the transfer fluxes derived from other competing mechanisms,such as triad interactions.Moreover,the numerical results show that the actual transfer rates into the edge wave from the three participating gravity waves are two-to three- orders of magnitude greater than bottom friction.