WorldWideScience

Sample records for front structure visualization

  1. Time Line Visualization of Research Fronts.

    Science.gov (United States)

    Morris, Steven A.; Yen, G.; Wu, Zheng; Asnake, Benyam

    2003-01-01

    Research fronts, defined as clusters of documents that tend to cite a fixed, time invariant set of base documents, are plotted as time lines for visualization and exploration. Illustrates the construction, exploration, and interpretation of time lines for identifying and visualizing temporal changes in research activity through journal articles.…

  2. STRUCTURE OF WAVE FRONT AND ORGANIZATION CENTER IN EXCITABLE MEDIA

    Institute of Scientific and Technical Information of China (English)

    刘深泉

    2004-01-01

    With help of establishing the moving coordinate on the wave front surface and the perturbation analysis in the boundary layer, the structures of wave front and organization center in excitable media were studied. The eikonal equation of wave front surface and general equation of organization center were obtained. These eikonal equations reveal the wave front surfaces have structures of twisted scroll wave and Mobius band, the organization centers have structures of knotted and linked ring. These theoretical results not only explain the wave patterns of BZ ( Belousov-Zhabotinskii ) chemical reaction but also give several possibility structures of wave front surface and organization center in general excitable media.

  3. Flow structure in front of the broad-crested weir

    Directory of Open Access Journals (Sweden)

    Zachoval Zbyněk

    2015-01-01

    Full Text Available The paper deals with research focused on description of flow structure in front of broad-crested weir. Based on experimental measurement, the flow structure in front of the weir (the recirculation zone of flow and tornado vortices and flow structure on the weir crest has been described. The determined flow character has been simulated using numerical model and based on comparing results the suitable model of turbulence has been recommended.

  4. The Hatteras Front: August 2004 velocity and density structure

    Science.gov (United States)

    Savidge, Dana K.; Austin, Jay A.

    2007-07-01

    The Hatteras Front is a persistent mesoscale cross-shelf oriented front off Cape Hatteras, North Carolina. It is the boundary between relatively cool, fresh Mid-Atlantic Bight shelf waters and warmer, saltier shelf waters of the South Atlantic Bight, which both converge along-shelf upon Cape Hatteras year round. The Frontal Interaction Near Cape Hatteras (FINCH) project was conducted in 2004-2005 to intensively sample the Hatteras Front with shipboard ADCP and undulating towed CTD. This paper documents velocity and density structures associated with the cross-shelf oriented zone of Hatteras Front during the August 2004 field season. Property gradients across the Hatteras Front are large, with temperature (T) and salinity (S) differences of ˜4-6°C, 2-5 psu, respectively over distances of 1-2 km. The T and S are not completely compensating, and a strong density (ρ) gradient also exists, with Δρ of ˜2 kg/m3 across a gentler 10 km wide front. The density gradient results in a steric sea-level height gradient of ˜1-2 cm across the Front, which is in approximate geostrophic balance with a surface intensified jet, directed shoreward along the cross-shelf oriented Front. The velocity is sheared with depth at 3.0 × 10-2 to 5.0 × 10-2 s-1 in the upper 5 m of the jet; a rate consistent with the density gradient according to the thermal wind relationship. Shoreward transport of ˜4.8 × 104 m3/s results from the surface intensified jet. The structure of the velocity field associated with the Hatteras Front resembles that of a slope-controlled buoyant plume, as described by Lentz and Helfrich (2002). Velocity and density structures are similar during both advancing (southwestward) and retreating (northeastward) motion of the Front.

  5. Fronts and Thermohaline Structure of the Brazil Current Confluence System

    Science.gov (United States)

    Severov, Dimitri

    and Thermohaline Structure of the Brazil Current Confluence System (BCCS) are stud-ied from climatic data, "Marathon Exp. Leg.8, 1984"data, and two Sea surface temperature (SST) data bases: "Meteor satellite"(1989-1994) and "ds277-Reynolds" (1981-2000).The South Atlantic Central Water (SACW) is divided in two main types: tropical (TW) and subtropical water (ST). Water masses, fronts, inter-frontal and frontal zones are analysed and classified: a) the water masses: Tropical Low-Salinity Water, Tropical Surface Water, Tropical Tropospheric Water, Subtropical Low-Salinity Water, Subtropical Surface Water, Subtropical Tropospheric Water. T,S characteristics of intermediate, deep and bottom water defined by different authors are confirmed and completed; b) the Inter-frontal Zones: Tropical/Brazil Current Zone, Sub-tropical Zone and Subantarctic Zone; c) the Frontal Zones: Subtropical, Subantarctic and Polar, and d) the Fronts: Subtropical Front of the Brazil Current, Principal Subtropical Front, North Subtropical Front, Subtropical Surface Front, South Subtropical Front, Subantarctic Surface Front, Subantarctic Front and Polar Front. Several stable T-S relationships are found below the friction layer and at the Fronts. The maximum gradient of the oceanographic characteris-tics occurs at the Brazil Current Front, which can be any of the subtropical fronts, depending on season. Minimum mean depth of the pycnocline coincides with the fronts of the BCCS, indicating the paths of low-salinity shelf waters into the open ocean. D. N. Severov (a) , V. Pshennikov (b) and A.V. Remeslo (c) a -Sección Oceanologé Facultad de Ciencia, Universidad de la Republica, Igué 4225, 11400 ıa, a Montevideo, Uruguay. Tel. (598-2) 525-8618, Fax (598-2) 525-8617, mail: dima@fcien.edu.uy b -Instituto de Física, Facultad de Ciencias, Universidad de la Republica, Igué 4225, 11400 Mon-a tevideo, Uruguay, mail: seva@fisica.edu.uy c -Atlantic Research Inst. For Fisheries Oceanology (Atlant

  6. Spin structure of the nucleon on the light front

    CERN Document Server

    Lorcé, Cédric

    2014-01-01

    We briefly review the spin structure of the nucleon and show that it is best thought in the light-front formulation. We discuss in particular the longitudinal and transverse spin sum rules, the proper definition of canonical orbital angular momentum and the spin-orbit correlation.

  7. Shock front field structure in low-density systems

    Science.gov (United States)

    Hua, Rui; Mucguffey, Christopher; Beg, Farhat; Sio, Hong; Ping, Yuan; Wilks, Scott; Heeter, Bob; Collins, Rip

    2016-10-01

    It is known that a shock front is not a simple discontinuity in density and temperature as depicted in commonly used hydro codes but also consists of self-generated fields associated with gradients in the electron pressure. A quasi-planar platform using broadband proton radiography has been developed to study this field structure at a shock front. The broad bandwidth offers energy-dependent measurements which quantitatively constrain both the potential and field width at the shock front. Experiments were conducted on the OMEGA EP, where three long pulse beams delivered 6 kJ in 2 ns for shock initiation in a tube filled with either pure Helium or mixture of Helium and Neon, and a short pulse of 850 J, 10 ps generated broadband protons for point-projection radiography. Simultaneous spatially resolved soft-x-ray spectroscopy provided shock velocity, particle velocity and thermal emission measurements, constraining density and temperature for the field generation. The data and modeling indicate that a multi-KeV potential was present at the shock front where a strong electron pressure gradient existed. This work was performed under DOE contract DE-AC52-07NA27344 with support from OFES Early Career program and LLNL LDRD program.

  8. Wishbone Structure for Front Independent Suspension of a Military Truck

    Directory of Open Access Journals (Sweden)

    V.V. Jagirdar

    2010-03-01

    Full Text Available Wishbone structure for double wishbone front-independent Suspension for a military truck application is presented. At present, the vehicle is equipped with rigid axle with leaf springs. There are two aspects that dictate the design of wishbone structure, viz. the path of relative motion between the constituents of the suspension system and the forces transmitted between them. Also, enhancement of mobility was made possible by maintaining the live axle in the system. A double wishbone, double coil spring with twin damper configuration was employed for this application. MBD Analysis was carried out using MSC ADAMS. A double wishboneindependent suspension has been designed for the front axle and has been successfully integrated with the vehicle.Defence Science Journal, 2010, 60(2, pp.178-183, DOI:http://dx.doi.org/10.14429/dsj.60.337

  9. Structuring front-end innovation activities throughout strategic product planning

    Directory of Open Access Journals (Sweden)

    Thaisa Rodrigues

    Full Text Available Abstract Strategic product planning (SPP for new product development (NPD in the front-end of innovation (FEI is a great challenge for managers and practitioners. This article analyzes the structuring process of FEI activities during SPP. A research was carried out with 78 industries from both food and furniture in Brazil. Our study revealed that FEI activities are structured in an intricate network with a high level of complexity and interdependence. The large amount of activities and the complexity in structuring them denote that companies are concerned to reduce uncertainties and risks intensifying the planning phase.

  10. Structure of Thunderstorm Gust Fronts with Topographic Effects

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Surface meteorological observations, associated with gust fronts produced by thunderstorm outflows over Tehran, an area surrounded by mountains, have been analyzed. Distinctive features are sudden drop in air temperature, up to 10℃, sharp increase in wind speed, up to 30 m s-1, with wind shift, to northwesterly, ressure jump, up to 4 hPa, humidity increase, up to 40%, and rain after some 20 min. Gust fronts which often occur in spring time, have a typical thickness of about 1.5 km and produce vertical wind shear of the order of 10-2s-1. Although these features seem to be common for most of the events, their intensities differ from one event to another, indicating that the gust fronts may occur in different sizes and shapes. Apart from a dominant effect on the formation of the original thunderstorms, topography appears to break up the frontal structure of the gust fronts. The internal Rossby radius of deformation for these flows is small enough (~ 100 km) for rotational effects to be minor.A laboratory model of the gust front (gravity current) also shows that it initially has a distinctive head with a turbulent wake, and can be broken up by topography. It is shown that when the environment is stratified, turbulence due to lobes and clefts instabilities near the nose of the current is suppressed. When the ground is rough, these instabilities are highly amplified and the internal Froude number of the flow is reduced. The bottom slope in the presence of rough topography leads to the break up of the current head and produces a broad and highly non-uniform head, recognized in the density signals.

  11. The structure of visual spaces

    NARCIS (Netherlands)

    Koenderink, J.J.; van Doorn, A.J.

    2008-01-01

    The “visual space” of an optical observer situated at a single, fixed viewpoint is necessarily very ambiguous. Although the structure of the “visual field” (the lateral dimensions, i.e., the “image”) is well defined, the “depth” dimension has to be inferred from the image on the basis of “monocular

  12. Shock front width and structure in supersonic granular flows.

    Science.gov (United States)

    Boudet, J F; Amarouchene, Y; Kellay, H

    2008-12-19

    The full structure of a shock front around a blunt body in a quasi-two-dimensional granular flow is studied. Two features, a large density gradient and a very small thickness of the front, characterize this shock and make it different from shocks in molecular gases. Both of these features can be understood using a modified version of the granular kinetic theory. Our model separates the particles into two subpopulations: fast particles having experienced no collisions and randomly moving particles. This separation is motivated by direct measurements of the particle velocities which show a bimodal distribution. Our results not only shed new light on the use of the granular kinetic theory under extreme conditions (shock formation) but bring new insight into the physics of shocks in general.

  13. Visual Narrative Structure

    Science.gov (United States)

    Cohn, Neil

    2013-01-01

    Narratives are an integral part of human expression. In the graphic form, they range from cave paintings to Egyptian hieroglyphics, from the Bayeux Tapestry to modern day comic books (Kunzle, 1973; McCloud, 1993). Yet not much research has addressed the structure and comprehension of narrative images, for example, how do people create meaning out…

  14. Visual narrative structure.

    Science.gov (United States)

    Cohn, Neil

    2013-04-01

    Narratives are an integral part of human expression. In the graphic form, they range from cave paintings to Egyptian hieroglyphics, from the Bayeux Tapestry to modern day comic books (Kunzle, 1973; McCloud, 1993). Yet not much research has addressed the structure and comprehension of narrative images, for example, how do people create meaning out of sequential images? This piece helps fill the gap by presenting a theory of Narrative Grammar. We describe the basic narrative categories and their relationship to a canonical narrative arc, followed by a discussion of complex structures that extend beyond the canonical schema. This demands that the canonical arc be reconsidered as a generative schema whereby any narrative category can be expanded into a node in a tree structure. Narrative "pacing" is interpreted as a reflection of various patterns of this embedding: conjunction, left-branching trees, center-embedded constituencies, and others. Following this, diagnostic methods are proposed for testing narrative categories and constituency. Finally, we outline the applicability of this theory beyond sequential images, such as to film and verbal discourse, and compare this theory with previous approaches to narrative and discourse.

  15. Structure of dynamical condensation fronts in the interstellar medium

    CERN Document Server

    Iwasaki, Kazunari

    2012-01-01

    In this paper, we investigate the structure of condensation fronts from warm diffuse gas to cold neutral medium (CNM) under the plane parallel geometry. The solutions have two parameters, the pressure of the cold neutral medium (CNM) and the mass flux across the transition front and their ranges are much wider than previous thought. First, we consider the pressure range where the three phases, the CNM, the unstable phase, and the warm neutral medium, can coexist in the pressure equilibrium. In a wide range of the mass flux, we find solutions connecting the CNM and unstable phase. Moreover, we find solutions in larger pressure range where there is only one thermal equilibrium state, or the CNM. These solutions can be realized in shock-compressed regions that is promising sites of the molecular cloud formation. We also find remarkable properties in our solutions. The heat conduction becomes less important with increasing mass flux, and the thickness of the transition layer is characterized by the cooling length...

  16. Speed and structure of turbulent fronts in pipe flow

    CERN Document Server

    Song, Baofang; Hof, Björn; Avila, Marc

    2016-01-01

    The dynamics of laminar-turbulent fronts in pipe flow is investigated for Reynolds numbers between Re=1900 and Re=5500 using extensive direct numerical simulations. In this range the flow undergoes a continuous transition from localised puffs to weakly expanding and ultimately to strongly expanding turbulent slugs (Barkley et al. 2015). We here investigate the physical distinction between these two types of slug by analysing time-resolved statistics of their downstream fronts in the frame moving at the bulk turbulent advection speed. While weak fronts travel slower than the bulk turbulent advection speed, implying local relaminarisation, strong fronts travel faster and so feed on the laminar flow ahead. At Re$\\approx$2900 the downstream front speed becomes faster than the advection speed, marking the onset of strong fronts. We argue that large temporal fluctuations of production and dissipation at the laminar-turbulent interface drive the dynamical switches between the two types of front observed up to Re$\\si...

  17. Visualizing structures of speech expressiveness

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Jensen, Karl Kristoffer; Graugaard, Lars

    2008-01-01

    . The Babel myth speaks about distance created when aspiring to the heaven as the reason for language division. Meanwhile, Locquin states through thorough investigations that only a few phonemes are present throughout history. Our interpretation is that a system able to recognize archetypal phonemes through......Speech is both beautiful and informative. In this work, a conceptual study of the speech, through investigation of the tower of Babel, the archetypal phonemes, and a study of the reasons of uses of language is undertaken in order to create an artistic work investigating the nature of speech...... vowels and consonants, and which converts the speech energy into visual particles that form complex visual structures, provides us with a mean to present the expressiveness of speech into a visual mode. This system is presented in an artwork whose scenario is inspired from the reasons of language...

  18. Front surface structured targets for enhancing laser-plasma interactions

    Science.gov (United States)

    Snyder, Joseph; George, Kevin; Ji, Liangliang; Yalamanchili, Sasir; Simonoff, Ethan; Cochran, Ginevra; Daskalova, Rebecca; Poole, Patrick; Willis, Christopher; Lewis, Nathan; Schumacher, Douglass

    2016-10-01

    We present recent progress made using front surface structured interfaces for enhancing ultrashort, relativistic laser-plasma interactions. Structured targets can increase laser absorption and enhance ion acceleration through a number of mechanisms such as direct laser acceleration and laser guiding. We detail experimental results obtained at the Scarlet laser facility on hollow, micron-scale plasma channels for enhancing electron acceleration. These targets show a greater than three times enhancement in the electron cutoff energy as well as an increased slope temperature for the electron distribution when compared to a flat interface. Using three-dimensional particle-in-cell (PIC) simulations, we have modeled the interaction to give insight into the physical processes responsible for the enhancement. Furthermore, we have used PIC simulations to design structures that are more advantageous for ion acceleration. Such targets necessitate advanced target fabrication methods and we describe techniques used to manufacture optimized structures, including vapor-liquid-solid growth, cryogenic etching, and 3D printing using two-photon-polymerization. This material is based upon work supported by the Air Force Office of Scientific Research under Award Number FA9550-14-1-0085.

  19. Unstable fronts and motile structures formed by microrollers

    Science.gov (United States)

    Driscoll, Michelle; Delmotte, Blaise; Youssef, Mena; Sacanna, Stefano; Donev, Aleksandar; Chaikin, Paul

    2017-04-01

    Condensation of objects into stable clusters occurs naturally in equilibrium and driven systems. It is commonly held that potential interactions, depletion forces, or sensing are the only mechanisms which can create long-lived compact structures. Here we show that persistent motile structures can form spontaneously from hydrodynamic interactions alone, with no sensing or potential interactions. We study this structure formation in a system of colloidal rollers suspended and translating above a floor, using both experiments and large-scale three-dimensional simulations. In this system, clusters originate from a previously unreported fingering instability, where fingers pinch off from an unstable front to form autonomous `critters’, whose size is selected by the height of the particles above the floor. These critters are a stable state of the system, move much faster than individual particles, and quickly respond to a changing drive. With speed and direction set by a rotating magnetic field, these active structures offer interesting possibilities for guided transport, flow generation, and mixing at the microscale.

  20. Visualizing ensembles in structural biology.

    Science.gov (United States)

    Melvin, Ryan L; Salsbury, Freddie R

    2016-06-01

    Displaying a single representative conformation of a biopolymer rather than an ensemble of states mistakenly conveys a static nature rather than the actual dynamic personality of biopolymers. However, there are few apparent options due to the fixed nature of print media. Here we suggest a standardized methodology for visually indicating the distribution width, standard deviation and uncertainty of ensembles of states with little loss of the visual simplicity of displaying a single representative conformation. Of particular note is that the visualization method employed clearly distinguishes between isotropic and anisotropic motion of polymer subunits. We also apply this method to ligand binding, suggesting a way to indicate the expected error in many high throughput docking programs when visualizing the structural spread of the output. We provide several examples in the context of nucleic acids and proteins with particular insights gained via this method. Such examples include investigating a therapeutic polymer of FdUMP (5-fluoro-2-deoxyuridine-5-O-monophosphate) - a topoisomerase-1 (Top1), apoptosis-inducing poison - and nucleotide-binding proteins responsible for ATP hydrolysis from Bacillus subtilis. We also discuss how these methods can be extended to any macromolecular data set with an underlying distribution, including experimental data such as NMR structures.

  1. Sciatic nerve injury repair: a visualized analysis of research fronts and development trends.

    Science.gov (United States)

    Liu, Guangyao; Jiang, Rui; Jin, Yan

    2014-09-15

    A total of 3,446 publications regarding sciatic nerve injury repair and protection indexed by Web of Science during 2000-2004 were used for a detailed analysis of temporal-spatial distribution characteristics. Reference co-citation networks of the 100 top-cited publications as per the number of total citations were created using the Web of Science database and the information visualization tool, CiteSpaceIII. The key words that showed high frequency in these publications were included for analyzing the research fronts and development trends for sciatic nerve injury repair and protection. Through word frequency trend analysis, studies on bone marrow mesenchymal stem cells, adipose-derived stem cells, and skeletal muscle-derived multipotent stem cells combined with tissue-engineered scaffold material will become the forefronts in the field of sciatic nerve injury repair and protection in the near future.

  2. Sciatic nerve injury repair:a visualized analysis of research fronts and development trends

    Institute of Scientific and Technical Information of China (English)

    Guangyao Liu; Rui Jiang; Yan Jin

    2014-01-01

    A total of 3,446 publications regarding sciatic nerve injury repair and protection indexed by Web of Science during 2000-2004 were used for a detailed analysis of temporal-spatial distribu-tion characteristics. Reference co-citation networks of the 100 top-cited publications as per the number of total citations were created using the Web of Science database and the information visualization tool, CiteSpaceIII. The key words that showed high frequency in these publications were included for analyzing the research fronts and development trends for sciatic nerve injury repair and protection. Through word frequency trend analysis, studies on bone marrow mesen-chymal stem cells, adipose-derived stem cells, and skeletal muscle-derived multipotent stem cells combined with tissue-engineered scaffold material will become the forefronts in the ifeld of sci-atic nerve injury repair and protection in the near future.

  3. The structure of precipitation fronts for finite relaxation time

    Energy Technology Data Exchange (ETDEWEB)

    Stechmann, Samuel N.; Majda, Andrew J. [New York University, Department of Mathematics and Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York, NY (United States)

    2006-11-15

    When convection is parameterized in an atmospheric circulation model, what types of waves are supported by the parameterization? Several studies have addressed this question by finding the linear waves of simplified tropical climate models with convective parameterizations. In this paper's simplified tropical climate model, convection is parameterized by a nonlinear precipitation term, and the nonlinearity gives rise to precipitation front solutions. Precipitation fronts are solutions where the spatial domain is divided into two regions, and the precipitation (and other model variables) changes abruptly at the boundary of the two regions. In one region the water vapor is below saturation and there is no precipitation, and in the other region the water vapor is above saturation level and precipitation is nonzero. The boundary between the two regions is a free boundary that moves at a constant speed. It is shown that only certain front speeds are allowed. The three types of fronts that exist for this model are drying fronts, slow moistening fronts, and fast moistening fronts. Both types of moistening fronts violate Lax's stability criterion, but they are robustly realizable in numerical experiments that use finite relaxation times. Remarkably, here it is shown that all three types of fronts are robustly realizable analytically for finite relaxation time. All three types of fronts may be physically unreasonable if the front spans an unrealistically large physical distance; this depends on various model parameters, which are investigated below. From the viewpoint of applied mathematics, these model equations exhibit novel phenomena as well as features in common with the established applied mathematical theories of relaxation limits for conservation laws and waves in reacting gas flows. (orig.)

  4. How Obstacles Perturb Population Fronts and Alter Their Genetic Structure.

    Directory of Open Access Journals (Sweden)

    Wolfram Möbius

    2015-12-01

    Full Text Available As populations spread into new territory, environmental heterogeneities can shape the population front and genetic composition. We focus here on the effects of an important building block of heterogeneous environments, isolated obstacles. With a combination of experiments, theory, and simulation, we show how isolated obstacles both create long-lived distortions of the front shape and amplify the effect of genetic drift. A system of bacteriophage T7 spreading on a spatially heterogeneous Escherichia coli lawn serves as an experimental model system to study population expansions. Using an inkjet printer, we create well-defined replicates of the lawn and quantitatively study the population expansion of phage T7. The transient perturbations of the population front found in the experiments are well described by a model in which the front moves with constant speed. Independent of the precise details of the expansion, we show that obstacles create a kink in the front that persists over large distances and is insensitive to the details of the obstacle's shape. The small deviations between experimental findings and the predictions of the constant speed model can be understood with a more general reaction-diffusion model, which reduces to the constant speed model when the obstacle size is large compared to the front width. Using this framework, we demonstrate that frontier genotypes just grazing the side of an isolated obstacle increase in abundance, a phenomenon we call 'geometry-enhanced genetic drift', complementary to the founder effect associated with spatial bottlenecks. Bacterial range expansions around nutrient-poor barriers and stochastic simulations confirm this prediction. The effect of the obstacle on the genealogy of individuals at the front is characterized by simulations and rationalized using the constant speed model. Lastly, we consider the effect of two obstacles on front shape and genetic composition of the population illuminating the

  5. Typical Structure, Variety, and Multi-Scale Characteristics of Meiyu Front

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yonggunag; CHEN Jiong; GE Guoqing; ZHU Peijun

    2008-01-01

    Meiyu front plays an important role in summer rainfall in central China. Based on the GMS-5 satellite images, NCEP reanalyses (2.5°×2.5°) and final analyses (1°×1°) data, and meteorological conventional sounding observations, the horizontal and vertical structures of the Meiyu front were summarized using multiple diagnostic variables, including winds, temperature, jet stream, front, pseduo-equivalent potential temperature, divergence, vertical motion, static instability, etc. In this paper, four cases were selected and analyzed, two of which are in 26-28 June and 23 July 2002 during the Experiment on Iteavy Rain in the Meiyu period in the lower reaches of the Yangtze River, and the others are in May and July 1998. The two cases in July 1998 and July 2002 are the secondary Meiyu front cases. The results show that the structures and characteristics of the Meiyu front are different for various cases, or at various places and time, or at various stages of one case, and the frontal characteristics can be converted from the polar front to the equatorial front. Because of the interaction of the different scale circulations in the high and low latitudes, the horizontal structure of the Meiyu front has various forms. The results in this paper also show that the typical Meiyu front consists of a narrow band with a high gradient of potential equivalent temperature below 500 hPa, south of which is warm and moist air mass, and north of which is the transformed air mass from the midlatitude ocean or polar continent. Below the mid troposphere, south of the front blows southwesterlies, while north blows easterlies. The ascending motion and precipitation usually occur ahead of the Meiyu front. In the upper troposphere, the subtropical front is above the Meiyu front, but two fronts are separated. In addition, the upper westerly jet stream and the easterlies to the south of the Meiyu front result in the upper divergent flow field. The multi-scale characteristics of the

  6. Front structure and dynamics in dense colonies of motile bacteria: Role of active turbulence

    CERN Document Server

    Chatterjee, Rayan; Perlekar, Prasad

    2016-01-01

    We study the spreading of a bacterial colony undergoing turbulent like collective motion. We present two minimalistic models to investigate the interplay between population growth and coherent structures arising from turbulence. Using Direct Numerical Simulation (DNS) of the proposed models we find that turbulence has two prominent effects on the spatial growth of the colony: (a) the front speed is enhanced, and (b) the front gets crumpled. Both these effects, which we highlight by using statistical tools, are markedly different in our two models. We also show that the crumpled front structure and the passive scalar fronts in random flows are related in certain regimes.

  7. Visual study of propagation of self-sustained evaporation front within the thickness of a thermal liquid layer

    Science.gov (United States)

    Zhukov, V. E.; Moiseev, M. I.; Kuznetsov, D. V.

    2016-10-01

    In the range of low reduced pressures, the development of self-sustained evaporation front along the heat-releasing surface at non-stationary heat release is an important factor that determines possible transition to film boiling at heat fluxes, significantly lower than the critical heat fluxes at stationary heat release. This paper presents the experimental results on the scale of a leading part of the interface of self-sustained evaporation front at stepped heat release. The scale of the leading part of the interface of the evaporation front is compared with the thermal layer thickness, registered using the shadow method of visualization at high-speed video shooting with up to 25,000 frames per second. Experiments were carried out in Freon R21 under the conditions of free convection at relative pressures of 0.032 - 0.068. It is shown that self-sustained evaporation front spreads along the heated wall within the thickness of a liquid layer, superheated relative to the saturation temperature. Dependence of the front velocity on wall superheating relative to the saturation temperature does not change with significant subcooling to the temperature of liquid saturation in the volume.

  8. Visualization of scalar topology for structural enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, C.L.; Pascucci, V.; Schikore, D.R.

    1998-09-22

    Scalar fields arise in every scientific application. Existing scalar visualization techniques require that the user infer the global scalar structure from what is frequently an insufficient display of information. We present a visualization technique which numerically detects the structure at all scales, removing from the user the responsibility of extracting information implicit in the data, and presenting the structure explicitly for analysis. We further demonstrate how scalar topology detection proves useful for correct visualization and image processing applications such as image co-registration, isocontouring, and mesh compression.

  9. Localized structures and front propagation in the Lengyel-Epstein model

    DEFF Research Database (Denmark)

    Jensen, O.; Pannbacker, Viggo Ole; Mosekilde, Erik

    1994-01-01

    Pattern selection, localized structure formation, and front propagation are analyzed within the framework of a model for the chlorine dioxide-iodine-malonic acid reaction that represents a key to understanding recently obtained Turing structures. This model is distinguished from previously studied...

  10. Reaction-Diffusion Systems: Front Propagation and Spatial Structures

    Science.gov (United States)

    Cencini, Massimo; Lopez, Cristobal; Vergni, Davide

    After the pioneering works of Kolmogorov, Petrovskii and Piskunov [1] and Fisher [2] in 1937 on the nonlinear diffusion equation and its traveling wave solutions, scientists from many different disciplines have been captivated by questions about structure, formation and dynamics of patterns in reactive media. Combustion, spreading of epidemics, diffusive transport of chemicals in cells and population dynamics are just a few examples bearing witness of the influence of those works in different areas of modern science.

  11. Physical Mechanism of Formation of the Bimodal Structure in the Meiyu Front System

    Institute of Scientific and Technical Information of China (English)

    CUI Xiao-Peng; GAO Shou-Ting; ZONG Zhi-Ping; LIU Wen-Ming; LI Xiao-Fan

    2005-01-01

    @@ The bimodal structure of the Meiyu front system is readdressed after Zhou et al.(2005). The physical mechanism of the formation of the bimodal distribution is discussed. The bimodal structure of the Meiyu front system considerably results from atmospheric moisture gradients, though atmospheric temperature gradients are also not negligible. According to the definition of equivalent potential temperature, and by scale analysis, we find that atmospheric equivalent potential temperature gradients, which could be regarded as an indicator of the Meiyu front system, could be mainly attributed to the variations of atmospheric potential temperature gradients with a scaling factor of 1 and moisture gradients multiplied by a scaling factor of an order of about 2.5 × 103,which means that small variations of atmospheric moisture gradients could lead to large variations of equivalent potential temperature gradients, and thus large variations of the Meiyu front system. Quantitative diagnostics with a mesoscale simulation data in the vicinity of the Meiyu front system show that moisture gradients contribute to equivalent potential temperature gradients more than potential temperature gradients.

  12. Method of fabricating conductive electrodes on the front and backside of a thin film structure

    Science.gov (United States)

    Tabada, Phillipe J.; Tabada, legal representative, Melody; Pannu, Satinderpall S.

    2011-05-22

    A method of fabricating a thin film device having conductive front and backside electrodes or contacts. Top-side cavities are first formed on a first dielectric layer, followed by the deposition of a metal layer on the first dielectric layer to fill the cavities. Defined metal structures are etched from the metal layer to include the cavity-filled metal, followed by depositing a second dielectric layer over the metal structures. Additional levels of defined metal structures may be formed in a similar manner with vias connecting metal structures between levels. After a final dielectric layer is deposited, a top surface of a metal structure of an uppermost metal layer is exposed through the final dielectric layer to form a front-side electrode, and a bottom surface of a cavity-filled portion of a metal structure of a lowermost metal layer is also exposed through the first dielectric layer to form a back-side electrode.

  13. Physical structure of the Barents Sea Polar Front near Storbanken in August 2007

    Science.gov (United States)

    Våge, S.; Basedow, S. L.; Tande, K. S.; Zhou, M.

    2014-02-01

    The Polar Front separating Atlantic Water (AW) and Arctic Water (ArW) is one of the most dominant meso- and large scale features in the Barents Sea. Here, the results of submeso-mesoscale (1-10 km) variability in physical fields associated with the Barents Sea Polar Front (BSPF) are reported from a high-resolution ADCP (Acoustic Doppler Current Profiler) and CTD (Conductivity-Temperature-Depth sensors) survey near Storbanken in August 2007. A surface front separating AW and melt water with a strong salinity gradient was present, while the subsurface BSPF was characterized by a strong temperature gradient and thermohaline compensation. Isopycnal mixing leading to the formation of Polar Front Water (PFW) was observed. The dominant flow was a barotropic southeastward along-frontal jet with two cores, coinciding with the surface front and the BSPF. This gives new insights into the circulation at the BSPF. Small-scale variability in the hydrographic and dynamic structures was observed, which were rarely resolved in previous cruises. Such submeso-mesoscale physical processes can potentially have significant impacts on the biogeochemistry and biology in the area, indicating the importance of parametrizing the processes in future climate models.

  14. Measurements of shock-front structure in multi-species plasmas on OMEGA

    Science.gov (United States)

    Rinderknecht, Hans G.; Park, H.-S.; Ross, J. S.; Wilks, S. C.; Amendt, P. A.; Heeter, R. F.; Katz, J.; Hoffman, N. M.; Vold, E.; Taitano, W.; Simakov, A.; Chacon, L.

    2016-10-01

    The structure of a shock front in a plasma with multiple ion species is measured for the first time in experiments on the OMEGA laser. Thomson scattering of a 263.25 nm probe beam is used to diagnose electron density, electron and ion temperature, ion species concentration, and flow velocity in strong shocks (M 5) propagating through low-density (ρ 0.1 mg/cc) plasmas composed of H(98%)+Ne(2%) and H(98%)+C(2%). Separation of the ion species within the shock front is inferred. Although shocks play an important role in ICF and astrophysical plasmas, the intrinsically kinetic nature of the shock front indicates the need for experiments to benchmark hydrodynamic models. Comparison with PIC, Vlasov-Fokker-Planck, and multi-component hydrodynamic simulations will be presented. This work performed under auspices of U.S. DOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. Visualizing vascular structures in virtual environments

    Science.gov (United States)

    Wischgoll, Thomas

    2013-01-01

    In order to learn more about the cause of coronary heart diseases and develop diagnostic tools, the extraction and visualization of vascular structures from volumetric scans for further analysis is an important step. By determining a geometric representation of the vasculature, the geometry can be inspected and additional quantitative data calculated and incorporated into the visualization of the vasculature. To provide a more user-friendly visualization tool, virtual environment paradigms can be utilized. This paper describes techniques for interactive rendering of large-scale vascular structures within virtual environments. This can be applied to almost any virtual environment configuration, such as CAVE-type displays. Specifically, the tools presented in this paper were tested on a Barco I-Space and a large 62x108 inch passive projection screen with a Kinect sensor for user tracking.

  16. Designing visual appearance using a structured surface

    DEFF Research Database (Denmark)

    Johansen, Villads Egede; Thamdrup, Lasse Højlund; Smitrup, Christian;

    2015-01-01

    We present an approach for designing nanostructured surfaces with prescribed visual appearances, starting at design analysis and ending with a fabricated sample. The method is applied to a silicon wafer structured using deep ultraviolet lithography and dry etching and includes preliminary design ...

  17. Visualization for Hyper-Heuristics. Front-End Graphical User Interface

    Energy Technology Data Exchange (ETDEWEB)

    Kroenung, Lauren [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Modern society is faced with ever more complex problems, many of which can be formulated as generate-and-test optimization problems. General-purpose optimization algorithms are not well suited for real-world scenarios where many instances of the same problem class need to be repeatedly and efficiently solved because they are not targeted to a particular scenario. Hyper-heuristics automate the design of algorithms to create a custom algorithm for a particular scenario. While such automated design has great advantages, it can often be difficult to understand exactly how a design was derived and why it should be trusted. This project aims to address these issues of usability by creating an easy-to-use graphical user interface (GUI) for hyper-heuristics to support practitioners, as well as scientific visualization of the produced automated designs. My contributions to this project are exhibited in the user-facing portion of the developed system and the detailed scientific visualizations created from back-end data.

  18. The Thermodynamic and Dynamical Features of Double Front Structures During 21-31 July 1998 in China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The daily 1°× 1° data of the Aviation (AVN) model, the black body temperature (TBB) data of cloud top, and cloud images by geostationary meteorological satellite (GMS) are used to identify a dew-point front near the periphery of the western Pacific subtropical high (WPSH). The results clearly demonstrate the existence of the dew-point front, and its thermodynamic and dynamic structural characteristics are analyzed in detail. The dew-point front is a transitional belt between the moist southwest monsoon flow and the dry adiabatic sinking flow near the WPSH, manifested by a large horizontal moisture gradient in the mid-lower troposphere and conjugated with the mei-yu front to form a predominant double-front structure associated with intense rainfall in the mei-yu period. The mei-yu front is located between 30°and 35°N, vertically extends from the ground level to the upper level and shifts northward. The dew-point front is to the south of the mei-yn front and lies up against the periphery of the WPSH. Generally, it is located between 850 hPa and 500 hPa. On the dew-point front side, the southwesterly prevails at the lower level and the northeasterly at the upper level; this wind distribution is different from that on the mei-yu front side. Vertical ascending motion exists between the two fronts, and there are descending motions on the north side of the mei-yu front and on the south side of the dew-point front, which form a secondary circulation. The dynamics of the double fronts also have some interesting features. At the lower level,positive vertical vorticity and obvious convergence between the two fronts are clearly identified. At the mid-lower level, negative local change of the divergence (corresponding to increasing convergence) is often embedded in the two fronts or against the mei-yu front. Most cloud clusters occur between the two fronts and propagate down stream in a wave-like manner.

  19. Strong nonlocal coupling stabilizes localized structures: an analysis based on front dynamics.

    Science.gov (United States)

    Fernandez-Oto, C; Clerc, M G; Escaff, D; Tlidi, M

    2013-04-26

    We investigate the effect of strong nonlocal coupling in bistable spatially extended systems by using a Lorentzian-like kernel. This effect through front interaction drastically alters the space-time dynamics of bistable systems by stabilizing localized structures in one and two dimensions, and by affecting the kinetics law governing their behavior with respect to weak nonlocal and local coupling. We derive an analytical formula for the front interaction law and show that the kinetics governing the formation of localized structures obeys a law inversely proportional to their size to some power. To illustrate this mechanism, we consider two systems, the Nagumo model describing population dynamics and nonlinear optics model describing a ring cavity filled with a left-handed material. Numerical solutions of the governing equations are in close agreement with analytical predictions.

  20. Visualizing Evaluation Structures using Layered Graph Drawings.

    Science.gov (United States)

    Onoue, Yosuke; Kukimoto, Nobuyuki; Sakamoto, Naohisa; Misue, Kazuo; Koyamada, Koji

    2016-03-18

    We propose a method for visualizing evaluation structures that is based on layered graph drawing techniques. An evaluation structure is a hierarchical structure of human cognition extracted from interviews based on the evaluation grid method. An evaluation structure can be defined as a directed acyclic graph (DAG). The Sugiyama framework is a popular method for constructing DAGs. A new layer assignment method that is a part of the Sugiyama framework is proposed to satisfy the requirements for drawing evaluation structures. We formulate a layer assignment problem by considering the sum of squares of arc lengths to be an integer quadratic programming (IQP) problem. Moreover, we transform the IQP problem into an equivalent integer linear programming (ILP) problem for computational efficiency. Evaluations demonstrate that the layered graph drawing with the proposed layer assignment method is preferred by users and aids in the understanding of evaluation structures.

  1. Visualizing structural dynamics of thylakoid membranes

    Science.gov (United States)

    Iwai, Masakazu; Yokono, Makio; Nakano, Akihiko

    2014-01-01

    To optimize photosynthesis, light-harvesting antenna proteins regulate light energy dissipation and redistribution in chloroplast thylakoid membranes, which involve dynamic protein reorganization of photosystems I and II. However, direct evidence for such protein reorganization has not been visualized in live cells. Here we demonstrate structural dynamics of thylakoid membranes by live cell imaging in combination with deconvolution. We observed chlorophyll fluorescence in the antibiotics-induced macrochloroplast in the moss Physcomitrella patens. The three-dimensional reconstruction uncovered the fine thylakoid membrane structure in live cells. The time-lapse imaging shows that the entire thylakoid membrane network is structurally stable, but the individual thylakoid membrane structure is flexible in vivo. Our observation indicates that grana serve as a framework to maintain structural integrity of the entire thylakoid membrane network. Both the structural stability and flexibility of thylakoid membranes would be essential for dynamic protein reorganization under fluctuating light environments. PMID:24442007

  2. Ionization fronts and shocked flows - The structure of the Orion Nebula at 0.1 arcsec

    Science.gov (United States)

    Hester, J. Jeff; Gilmozzi, R.; O'Dell, C. R.; Faber, S. M.; Campbell, Bel; Kelsall, T.

    1991-01-01

    Initial results are presented from images of the Orion Nebula obtained with the HST Wide-Field Camera with a resolution of better than about 10 to the 15th cm. The morphology of the forbidden S II emission is markedly different from that seen in H-beta and forbidden O II. The forbidden S II is dominated by filamentary features with widths between 0.1 and 1 arcsesc which sharply highlight ionization fronts moving into dense neutral material. While the surfaces into which these fronts are moving are textured, subarcsec clumps with high density contrast are uncommon. The fields contains a number of HH objects whose structure is revealed by the HST, and which are described.

  3. Ionization fronts and shocked flows - The structure of the Orion Nebula at 0. 1 arcsec

    Energy Technology Data Exchange (ETDEWEB)

    Hester, J.J.; Gilmozzi, R.; O' Dell, C.R.; Faber, S.M.; Campbell, B.; Kelsall, T. (California Institute of Technology, Pasadena (USA) Space Telescope Science Institute, Baltimore, MD (USA) ESA, Space Science Dept., Noordwijk (Netherlands) Rice Univ., Houston, TX (USA) Lick Observatory, Santa Cruz, CA (USA) New Mexico Univ., Albuquerque (USA) NASA, Goddard Space Flight Center, Greenbelt, MD (USA))

    1991-03-01

    Initial results are presented from images of the Orion Nebula obtained with the HST Wide-Field Camera with a resolution of better than about 10 to the 15th cm. The morphology of the forbidden S II emission is markedly different from that seen in H-beta and forbidden O II. The forbidden S II is dominated by filamentary features with widths between 0.1 and 1 arcsesc which sharply highlight ionization fronts moving into dense neutral material. While the surfaces into which these fronts are moving are textured, subarcsec clumps with high density contrast are uncommon. The fields contains a number of HH objects whose structure is revealed by the HST, and which are described. 29 refs.

  4. Dynamic sign structures in visual art and music

    DEFF Research Database (Denmark)

    Zeller, Jörg

    2006-01-01

    Seemingly static meaning carriers in visual art are considered as aspects of holistic dynamical sign structures.......Seemingly static meaning carriers in visual art are considered as aspects of holistic dynamical sign structures....

  5. Dynamic sign structures in visual art and music

    DEFF Research Database (Denmark)

    Zeller, Jörg

    2006-01-01

    Seemingly static meaning carriers in visual art are considered as aspects of holistic dynamical sign structures.......Seemingly static meaning carriers in visual art are considered as aspects of holistic dynamical sign structures....

  6. Crystal structure of complete rhinovirus RNA polymerase suggests front loading of protein primer.

    Science.gov (United States)

    Appleby, Todd C; Luecke, Hartmut; Shim, Jae Hoon; Wu, Jim Z; Cheney, I Wayne; Zhong, Weidong; Vogeley, Lutz; Hong, Zhi; Yao, Nanhua

    2005-01-01

    Picornaviruses utilize virally encoded RNA polymerase and a uridylylated protein primer to ensure replication of the entire viral genome. The molecular details of this mechanism are not well understood due to the lack of structural information. We report the crystal structure of human rhinovirus 16 3D RNA-dependent RNA polymerase (HRV16 3Dpol) at a 2.4-A resolution, representing the first complete polymerase structure from the Picornaviridae family. HRV16 3Dpol shares the canonical features of other known polymerase structures and contains an N-terminal region that tethers the fingers and thumb subdomains, forming a completely encircled active site cavity which is accessible through a small tunnel on the backside of the molecule. The small thumb subdomain contributes to the formation of a large cleft on the front face of the polymerase which also leads to the active site. The cleft appears large enough to accommodate a template:primer duplex during RNA elongation or a protein primer during the uridylylation stage of replication initiation. Based on the structural features of HRV16 3Dpo1 and the catalytic mechanism known for all polymerases, a front-loading model for uridylylation is proposed.

  7. Visual mining of semi-structured data

    CERN Document Server

    CERN. Geneva; Posada, Jorge; Quartulli, Marco

    2013-01-01

    Background Vicomtech is visiting CERN to expose their activities and explore possible lines of collaboration. As part of the programme they will be offering a presentation, staged in three parts: Presentation of Vicomtech – Seán Gaines Descriptions of technologies and specialities – Dr. Jorge Posada Details on projects related to the development of visually-based algorithms for intelligent storage, processing, visualization and interaction with Big Data, for massive sources of information. – Dr. Marco Quartulli. The full programme to the visit is here Abstract Mining semi-structured data is fundamental for archive monitoring, understanding and exploitation. Typical analysis systems are based on a three-tiered architecture, in which efficient databases feed highly parallelised application servers that in turn feed client user interfaces. Yet the sharing of analysis, content identification and semantic level summarization tasks among the two bot...

  8. Mirror mode structures ahead of dipolarization front near the neutral sheet observed by Cluster

    Science.gov (United States)

    Wang, G. Q.; Zhang, T. L.; Volwerk, M.; Schmid, D.; Baumjohann, W.; Nakamura, R.; Pan, Z. H.

    2016-09-01

    Magnetic compressional structures ahead of a dipolarization front (DF) on 30 August 2002 are investigated by using Cluster data. Our findings are as follows: (1) the structures, observed near the neutral sheet, are mainly compressional and dominant in BZ; (2) they are almost nonpropagating relative to the local ion bulk flow and their lengths are several local proton gyroradius; (3) the ion density increases when BT decreases; (4) ions are partially trapped by the structures with parallel and perpendicular velocities varying in antiphase; and (5) local conditions are favorable for excitation of the mirror instability, and we suggest that these structures are mirror mode-like. Our findings also suggest that local conditions ahead of the DF are viable for exciting the mirror instability to generate mirror mode waves or structures.

  9. The vacuum structure of light-front $\\phi^{4}_{1+1}$-theory

    CERN Document Server

    Heinzl, T; Werner, E; Zellermann, B

    1995-01-01

    We discuss the vacuum structure of \\phi^4-theory in 1+1 dimensions quantised on the light-front x^+ =0. To this end, one has to solve a non-linear, operator-valued constraint equation. It expresses that mode of the field operator having longitudinal light-front momentum equal to zero, as a function of all the other modes in the theory. We analyse whether this zero mode can lead to a non-vanishing vacuum expectation value of the field \\phi and thus to spontaneous symmetry breaking. In perturbation theory, we get no symmetry breaking. If we solve the constraint, however, non-perturbatively, within a mean-field type Fock ansatz, the situation changes: while the vacuum state itself remains trivial, we find a non-vanishing vacuum expectation value above a critical coupling. Exactly the same result is obtained within a light-front Tamm-Dancoff approximation, if the renormalisation is done in the correct way.

  10. Kinetic structure and wave properties associated with sharp dipolarization front observed by Cluster

    Directory of Open Access Journals (Sweden)

    S. Y. Huang

    2012-01-01

    Full Text Available Multiple dipolarization fronts (DFs were observed by Cluster spacecraft in the magnetotail during a substorm. These DFs were kinetic structures, embedded in the bursty plasma flow, and moved earthward (mainly and dawnward. Intense electric field, parallel and perpendicular currents were detected in the DF layer. These front layers were energy dissipation region (load region where the energy of electromagnetic fields were transferred to the plasma thermal and kinetic energy. This dissipation was dominated by electrons. There were enhancements of plasma waves around the DF region: wavelet results show that wave activities around the ion cyclotron frequency in the front layer were generated by Alfvén ion cyclotron instability; whistler waves were also detected before, during and after the DFs, which are triggered by electron temperature anisotropy and coincident with enhancement of energetic electron fluxes. The observation of these waves could be important for the understanding of evolution of DF and electron energization during the substorm. We discuss the generation mechanism of the DFs and suggest that these DFs were generated in the process of transient reconnection, and then traveled toward the Earth.

  11. The structure and dynamics of the research fronts in HIV/AIDS research: part-whole and adaptive specialization

    CERN Document Server

    Fajardo-Ortiz, David; Duran, Luis; Dumontier, Michel; Lara, Miguel; Ochoa, Hector; Castano, Victor M

    2016-01-01

    In this paper, we have identified and analyzed the emergence, structure and dynamics of the paradigmatic research fronts that established the fundamentals of the biomedical knowledge on HIV/AIDS. A search of papers with the identifiers "HIV/AIDS", "Human Immunodeficiency Virus" and "Acquired Immunodeficiency Syndrome" in the Web of Science (Thomson Reuters), was carried out. A citation network of those papers was constructed. Then, a sub-network of the papers with the highest number of inter-citations (with a minimal in-degree of 30) was selected to perform a combination of network clustering and text mining to identify the paradigmatic research fronts and analyze their dynamics. Seven research fronts were identified in this sub-network. Each one of the fronts are related to one of the following topics: "preliminary pathology research", "virus entry", "virus tropism", "drug resistance", "genetic expression", "assembly", and "virus replication". The emergence of these fronts occurred in successive "waves" over...

  12. Employment of a metal microgrid as a front electrode in a sandwich-structured photodetector.

    Science.gov (United States)

    Zhang, Junying; Cai, Chao; Pan, Feng; Hao, Weichang; Zhang, Weiwei; Wang, Tianmin

    2009-07-01

    A highly UV-transparent metal microgrid was prepared and employed as the front electrode in a sandwich-structured ultraviolet (UV) photodetector using TiO(2) thin film as the semiconductor layer. The photo-generated charger carriers travel a shorter distance before reaching the electrodes in comparison with a photodetector using large-spaced interdigitated metal electrodes (where distance between fingers is several to tens of micrometers) on the surface of the semiconductor film. This photodetector responds to UV light irradiation, and the photocurrent intensity increases linearly with the irradiation intensity below 0.2 mW/cm(2).

  13. A Diagnostic Analysis of the Simulated Structure of a Meiyu Front System in 1999

    Institute of Scientific and Technical Information of China (English)

    CUI Xiaopeng; GAO Shouting; ZHANG Haixia; HAO Shifeng

    2009-01-01

    A numerical simulation of a torrential rain event occurring in the Jiang-Huai Valley of China from 22-24 June 1999 is performed and analyzed by using the PSU/NCAR MM5 mesoscale non-hydrostatic model. The high-resolution model output data are utilized to diagnose the double front structure, and the distributions of potential temperature, equivalent potential temperature, and specific humidity in the vicinity of the Meiyu Front System (MYFS) in the Jiang-Huai Valley. The results show that both the potential temperature gradient and the specific humidity gradient have important impacts on the two strong equivalent potential temperature gradient zones associated with the double front structure of the MYFS, but the latter (tools ture gradient) is more important. In addition, the tendency equation of specific humidity gradient is theoretically derived. It shows that variations of the specific humidity gradient are related to the advection, convergence/divergence, horizontal and vertical vorticities (secondary circulation) effects and the gradient of water vapor source/sink. As an example, the budget of the meridional component of the tendency equation is selected and diagnosed by using the above model simulation data of the torrential rain event. It is shown that the variation of the specific humidity gradient averaged throughout the simulation is mainly controlled by the convergence/divergence effect, the secondary circulation effect associated with the horizontal vorticities, and the water vapor source/sink effect. Since the water vapor source/sink is often formed from the phase change processes of water vapor in the air and thus directly associated with cloud and precipitation microphysics processes, the variation of the specific humidity gradient is closely related with cloud and precipitation microphysics and the distribution, development and evolution of cloud and rainfall systems. The double front structure of the MYFS provides an advantageous environmental

  14. Genetic structure among greater white-fronted goose populations of the Pacific Flyway

    Science.gov (United States)

    Ely, Craig R.; Wilson, Robert E.; Talbot, Sandra

    2017-01-01

    An understanding of the genetic structure of populations in the wild is essential for long-term conservation and stewardship in the face of environmental change. Knowledge of the present-day distribution of genetic lineages (phylogeography) of a species is especially important for organisms that are exploited or utilize habitats that may be jeopardized by human intervention, including climate change. Here, we describe mitochondrial (mtDNA) and nuclear genetic (microsatellite) diversity among three populations of a migratory bird, the greater white-fronted goose (Anser albifrons), which breeds discontinuously in western and southwestern Alaska and winters in the Pacific Flyway of North America. Significant genetic structure was evident at both marker types. All three populations were differentiated for mtDNA, whereas microsatellite analysis only differentiated geese from the Cook Inlet Basin. In sexual reproducing species, nonrandom mate selection, when occurring in concert with fine-scale resource partitioning, can lead to phenotypic and genetic divergence as we observed in our study. If mate selection does not occur at the time of reproduction, which is not uncommon in long-lived organisms, then mechanisms influencing the true availability of potential mates may be obscured, and the degree of genetic and phenotypic diversity may appear incongruous with presumed patterns of gene flow. Previous investigations revealed population-specific behavioral, temporal, and spatial mechanisms that likely influence the amount of gene flow measured among greater white-fronted goose populations. The degree of observed genetic structuring aligns well with our current understanding of population differences pertaining to seasonal movements, social structure, pairing behavior, and resource partitioning.

  15. Attenuation structure beneath the volcanic front in northeastern Japan from broad-band seismograms

    Science.gov (United States)

    Takanami, Tetsuo; Selwyn Sacks, I.; Hasegawa, Akira

    2000-10-01

    Anelastic structure in the asthenosphere beneath the volcanic front in northeastern Japan arc is estimated by using the spectral amplitude ratio data of P and S waves from about 100 events which occurred in the subducting Pacific slab below Japan. These earthquakes occurred within a 90 km radius centered about the station Sawauchi (SWU), with focal depths ranging from 60 to 200 km. Waveforms were recorded by the Carnegie broad-band three-component seismograph and were corrected for instrument responses, crustal reverberations, corner frequencies, and superimposed noise. Ray paths and travel times of P and S waves are calculated using a three-dimensional velocity model [Zhao, D., Hasegawa, A., Horiuchi, S., 1992. J. Geophys. Res. 97, 19909-19928]. We find a low- Q region ( QS˜70) extending down to 55 km depth from the lower crust beneath the volcanic front. Using Q-temperature laboratory results [Sato, H., Sacks, I.S., Murase, T., Muncill, G., Fukushima, H., 1989. J. Geophys. Res. 94, 10647-10661], this implies a temperature of about 130°C higher than the eastern forearc region and about 30°C higher than the western backarc region, in good agreement with the tomographic results of Zhao et al. [Zhao, D., Hasegawa, A., Horiuchi, S., 1992. J. Geophys. Res. 97, 19909-19928]. This suggests that low velocities in the crust and uppermost mantle beneath SWU may be explained by a subsolidus temperature increase without partial melting.

  16. Hydrological character and sea-current structure in the front of Amery Ice Shelf

    Institute of Scientific and Technical Information of China (English)

    Chen Hongxia; Pan Zengdi; Jiao Yutian; Xiang Baoqiang

    2005-01-01

    Hydrological character and Sea-current profiles structure are studied and analyzed in sea-area of the front of Amery Ice Shelf, Prydz Bay with LADCP, CTD dana. These LADCP, CTD data were acquired during the 19th Chinese Antarctic Scientific Expedition. Results of this study agree with that, there exist four different kinds of water masses in the area of the front of Amery Ice Shelf in the summer of Antarctica. Current distribution presents a semi-circumfluence which flows in at the east and flows out in the west. Moreover, clockwise andd anti -clockwise vortices were found in upper layer and mid-layer in the Prydz Bay. Western areas of these anticlockwise vortices are positions of inflows from Prydz Bay to Amery Ice Shelf. The source of these inflows is the coastal westward current originated in the east of Prydz Bay. All these characteristics come down to the pattern of circumfluence, ice melt rate under Ice Shelf, scale of Ice Shelf water production and form of water exchanges between area of Ice Shelf and area of Prydz Bay.

  17. Velocity structure, front position changes and calving of the tidewater glacier Kronebreen, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Sund

    2011-01-01

    Full Text Available Glacier calving and retreat constitute a substantial portion of the ablation of tidewater glaciers and is therefore of interest in climate models in order to get more accurate predictions of future development of glaciers and their contribution to sea level rise. We use photogrammetry, global navigation satellite system, surface elevation and bathymetric data from Kronebreen to test a crevasse-depth calving model, investigate meteorological controls on near terminus velocity fluctuations and finally short-term and longer term (multi annual to decadal controls of the front positions and calving. The relationship between velocity structure, crevasse formation, and calving events at Kronebreen is found to be more complex than outlined in the crevasse-depth calving model. Surface meltwater is found to be closely connected to velocities, but no direct relationship between velocity variation and calving could be seen along the investigated transect. On a long term basis the front positions of Kronebreen are results of a combination of several factors, particularly the interplay with the confluent glacier Kongsvegen, and change in discharge fluxes as a result of surge dynamics. Yet the bed topography is found to be an important control on the retreat of this glacier, similar to several other tidewater glaciers.

  18. Processing visual rhetoric in advertisements: Interpretations determined by verbal anchoring and visual structure

    NARCIS (Netherlands)

    Lagerwerf, L.; Hooijdonk, van C.M.J.; Korenberg, A.

    2012-01-01

    This research investigated meaning operation in relation to verbal anchoring and visual structure of visual rhetoric in advertisements. Meaning operation refers to the relation between meaningful visual elements, and determines the number of interpretations of an image. Meaning operation ‘connection

  19. Results of the MERKUR experiment: Structural changes of a weak cold front in the area of the Alps

    Energy Technology Data Exchange (ETDEWEB)

    Freytag, C.; Beier, N. (ed.)

    1987-03-01

    The examination of fronts and the effect on them of mountains are the research aims of ALPEX. A whole series of works are available on about 15 'front events' during ALPEX-SOP (special observing period March-April 1982). The first results on a weak cold front are shown, which reached the southern spur of the Alps on the 2nd and 3rd of April 1982, but which did not cross the mountains. The passage of the front came in the 3rd intensive measurement phase of the MERKUR experiment. Apart from the ALPEX soundings, the additional measurements during MERKUR are also available. This permits structural investigations with relatively good resolution in the border area mountains/foothills and in the mountains themselves.

  20. Structure and seasonal variability of fronts in the Southeast Indian Ocean along sections from Fremantle, Australia to Antarctic Zhongshan Station

    Institute of Scientific and Technical Information of China (English)

    YANG Wei; GAO Libao; LI Ruixiang; LIU Changjian; YAN Jinhui

    2016-01-01

    Four sections of expendable conductivity-temperature-depth (XCTD) proifles from Fremantle, Australia to Antarctic Zhongshan Station and Moderate Resolution Imaging Spectroradiometer-Aquarius (MODIS-A) sea surface temperature (SST) products were used to study the structure and seasonal variability of Southeast Indian Ocean fronts. Water mass analysis showed that surface water masses in the Southeast Indian Ocean were less salty in March than in November. Compared with November, the subtropical front (STF) moved southward about one degree of latitude in March, whereas seasonal variability of the subantarctic front (SAF) and polar front (PF) locations was not obvious. In March, the saline front moved northward about two degrees of latitude relative to the thermal front in the upper 100 m at the SAF, which was the northern boundary of sub-Antarctic surface water (SASW). Analysis of climatological SST gradients from the satellite data showed that regions of enhanced sea surface temperature (SST) gradients were collocated with frontal locations identiifed with the XCTD data using water mass criteria. The surface expression of the PF identiifed by the SST gradient was further south by about one degree of latitude relative to the subsurface expression of the PF identiifed by the northern boundary of cold water.

  1. Visualization of database structures for information retrieval

    Directory of Open Access Journals (Sweden)

    Grete Lisbjerg Jensen

    1994-12-01

    Full Text Available This paper describes the Book House system, which is designed to support children's information retrieval in libraries as part of their education. It is a shareware program available on CD-ROM or floppy disks, and comprises functionality for database searching as well as for classifying and storing book information in the database. The system concept is based on an understanding of children's domain structures and their capabilities for categorization of information needs in connection with their activities in schools, in school libraries or in public libraries. These structures are visualized in the interface by using metaphors and multimedia technology. Through the use of text, images and animation, the Book House encourages children - even at a very early age - to learn by doing in an enjoyable way, which plays on their previous experiences with computer games. Both words and pictures can be used for searching; this makes the system suitable for all age groups. Even children who have not yet learned to read properly can, by selecting pictures, search for and find those books they would like to have read aloud. Thus, at the very beginning of their school life, they can learn to search for books on their own. For the library community, such a system will provide an extended service which will increase the number of children's own searches and also improve the relevance, quality and utilization of the book collections in the libraries. A market research report on the need for an annual indexing service for books in the Book House format is in preparation by the Danish Library Centre A/S.

  2. Visualizing Structure and Dynamics of Disaccharide Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, J. F.; Beckham, G. T.; Himmel, M. E.; Crowley, M. F.

    2012-01-01

    We examine the effect of several solvent models on the conformational properties and dynamics of disaccharides such as cellobiose and lactose. Significant variation in timescale for large scale conformational transformations are observed. Molecular dynamics simulation provides enough detail to enable insight through visualization of multidimensional data sets. We present a new way to visualize conformational space for disaccharides with Ramachandran plots.

  3. Structured Attentions for Visual Question Answering

    OpenAIRE

    Zhu, Chen; Zhao, Yanpeng; Huang, Shuaiyi; Tu, Kewei; Ma, Yi

    2017-01-01

    Visual attention, which assigns weights to image regions according to their relevance to a question, is considered as an indispensable part by most Visual Question Answering models. Although the questions may involve complex relations among multiple regions, few attention models can effectively encode such cross-region relations. In this paper, we demonstrate the importance of encoding such relations by showing the limited effective receptive field of ResNet on two datasets, and propose to mo...

  4. Structuring front office and back office work in service delivery systems - An empirical study of three design decisions

    NARCIS (Netherlands)

    Zomerdijk, Leonleke G.; de Vries, Jan

    2007-01-01

    Purpose - The aim of this paper is to investigate how the distinction between contact and non-contact activities influences the design of service delivery systems and to identify key design decisions for structuring front office and back office work. Design/methodology/approach - Building on current

  5. Characterization of waferstepper and process related front- to backwafer overlay errors in bulk micro machining using electrical overlay test structures

    NARCIS (Netherlands)

    Van Zeijl, H.W.; Bijnen, F.G.C.; Slabbekoorn, J.

    2004-01-01

    To validate the Front- To Backwafer Alignment (FTBA) calibration and to investigate process related overlay errors, electrical overlay test structures are used that requires FTBA [1]. Anisotropic KOH etch through the wafer is applied to transfer the backwafer pattern to the frontwafer. Consequently,

  6. A novel pseudo resistor structure for biomedical front-end amplifiers.

    Science.gov (United States)

    Yu-Chieh Huang; Tzu-Sen Yang; Shun-Hsi Hsu; Xin-Zhuang Chen; Jin-Chern Chiou

    2015-08-01

    This study proposes a novel pseudo resistor structure with a tunable DC bias voltage for biomedical front-end amplifiers (FEAs). In the proposed FEA, the high-pass filter composed of differential difference amplifier and a pseudo resistor is implemented. The FEA is manufactured by using a standard TSMC 0.35 μm CMOS process. In this study, three types FEAs included three different pseudo resistor are simulated, fabricated and measured for comparison and electrocorticography (ECoG) measurement, and all the results show the proposed pseudo resistor is superior to other two types in bandwidth. In chip implementation, the lower and upper cutoff frequencies of the high-pass filter with the proposed pseudo resistor are 0.15 Hz and 4.98 KHz, respectively. It also demonstrates lower total harmonic distortion performance of -58 dB at 1 kHz and higher stability with wide supply range (1.8 V and 3.3 V) and control voltage range (0.9 V and 1.65 V) than others. Moreover, the FEA with the proposed pseudo successfully recorded spike-and-wave discharges of ECoG signal in in vivo experiment on rat with pentylenetetrazol-induced seizures.

  7. Cordilleran front range structural features in northwest Montana interpreted from vintage seismic reflection data

    Science.gov (United States)

    Porter, Mason C.; Rutherford, Bradley S.; Speece, Marvin A.; Mosolf, Jesse G.

    2016-04-01

    Industry seismic reflection data spanning the Rocky Mountain Cordillera front ranges of northwest Montana were reprocessed and interpreted in this study. Five seismic profiles represent 160 km of deep reflection data collected in 1983 that span the eastern Purcell anticlinorium, Rocky Mountain Trench (RMT), Rocky Mountain Basal Décollement (RMBD), and Lewis thrust. The data were reprocessed using modern techniques including refraction statics, pre-stack time migration (PSTM), and pre- and post-stack depth migration. Results indicate the RMBD is 8-13 km below the Earth's surface and dip 3-10° west. Evidence for the autochthonous Mesoproterozoic Belt and basal Cambrian rocks beneath the RMBD is present in all of the profiles and appears to extend east of the RMT. The Lewis thrust was identified in the seismic profiles and appears to sole into the RMBD east of the RMT. The RMT fault system has a dip displacement of 3-4 km and forms a half graben filled with 1 km of unconsolidated Tertiary sedimentary deposits. The RMT and adjacent Flathead fault systems are interpreted to be structurally linked and may represent a synthetic, en echelon fault system.

  8. Frontal dynamics in a California Current System shallow front: 1. Frontal processes and tracer structure

    Science.gov (United States)

    Pallã S-Sanz, E.; Johnston, T. M. S.; Rudnick, D. L.

    2010-12-01

    The three-dimensional dynamics in a shallow front are examined using density and current data from two surveys 100 km offshore of Monterey Bay, California. Survey 1 is forced by down-front winds, and both surveys have considerable cross-front density gradients and flow curvature. The maximum Rossby numbers on the dense side reached maxima of +0.60 in survey 1 and +0.45 in survey 2. Downwelling occurs in regions of confluence (frontogenesis) associated with potential vorticity (PV) change and thermal wind imbalance. Streamers of particulate matter and PV are advected southeastward by the frontal jet and downward. Nonlinear Ekman currents advect dense water over light water in the presence of down-front winds, which leads to upwelling along the front and downwelling on the light side of the front. At sites of active ageostrophic secondary circulation (ASC), induced by frontogenesis or Ekman effects, the observed cross-front ageostrophic velocity is consistent with the diagnosed vertical velocity. Furthermore, in survey 2, ageostrophic divergence may play an important role at the curved front, presumably counteracting quasi-geostrophic frontogenesis due to isopycnal confluence. Downward frictional vertical PV flux below the surface extracts PV from the pycnocline and reinforces the frontogenetic vertical PV flux. PV destruction at the surface is inferred from a low PV anomaly below the mixed layer in survey 2. Since the magnitude of the frontogenetic ASC is only twice the magnitude of Ekman suction, external forcing may have a considerable impact on the vertical heat and PV fluxes.

  9. Structural and functional changes across the visual cortex of a patient with visual form agnosia.

    Science.gov (United States)

    Bridge, Holly; Thomas, Owen M; Minini, Loredana; Cavina-Pratesi, Cristiana; Milner, A David; Parker, Andrew J

    2013-07-31

    Loss of shape recognition in visual-form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for "perception" and "action"). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted in a persisting visual-form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF's cortex, combining structural and functional measurements. We present the first accurate quantification of the changes in thickness across DF's occipital cortex, finding the most substantial loss in the lateral occipital cortex (LOC). There are reduced white matter connections between LOC and other areas. Functional measures show pockets of activity that survive within structurally damaged areas. The topographic mapping of visual areas showed that ordered retinotopic maps were evident for DF in the ventral portions of visual cortical areas V1, V2, V3, and hV4. Although V1 shows evidence of topographic order in its dorsal portion, such maps could not be found in the dorsal parts of V2 and V3. We conclude that it is not possible to understand fully the deficits in object perception in visual-form agnosia without the exploitation of both structural and functional measurements. Our results also highlight for DF the cortical routes through which visual information is able to pass to support her well-documented abilities to use visual information to guide actions.

  10. The Role of Visual Representations for Structuring Classroom Mathematical Activity

    Science.gov (United States)

    David, Maria Manuela; Tomaz, Vanessa Sena

    2012-01-01

    It is our presupposition that there is still a need for more research about how classroom practices can exploit the use and power of visualization in mathematics education. The aim of this article is to contribute in this direction, investigating how visual representations can structure geometry activity in the classroom and discussing teaching…

  11. Evaluation of Software for Introducing Protein Structure: Visualization and Simulation

    Science.gov (United States)

    White, Brian; Kahriman, Azmin; Luberice, Lois; Idleh, Farhia

    2010-01-01

    Communicating an understanding of the forces and factors that determine a protein's structure is an important goal of many biology and biochemistry courses at a variety of levels. Many educators use computer software that allows visualization of these complex molecules for this purpose. Although visualization is in wide use and has been associated…

  12. Structural Integrity Inspection and Visualization System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA's need for compact nondestructive evaluation (NDE) of the structural integrity of spacecraft components and structures, Physical Optics Corporation...

  13. Analysis of moving surface structures at a laser-induced boiling front

    Science.gov (United States)

    Matti, R. S.; Kaplan, A. F. H.

    2014-10-01

    Recently ultra-high speed imaging enabled to observe moving wave patterns on metal melts that experience laser-induced boiling. In laser materials processing a vertical laser-induced boiling front governs processes like keyhole laser welding, laser remote fusion cutting, laser drilling or laser ablation. The observed waves originate from temperature variations that are closely related to the melt topology. For improved understanding of the essential front mechanisms and of the front topology, for the first time a deeper systematic analysis of the wave patterns was carried out. Seven geometrical shapes of bright or dark domains were distinguished and categorized, in particular bright peaks of three kinds and dark valleys, often inclined. Two categories describe special flow patterns at the top and bottom of the front. Dynamic and statistical analysis has revealed that the shapes often combine or separate from one category to another when streaming down the front. The brightness of wave peaks typically fluctuates during 20-50 μs. This variety of thermal wave observations is interpreted with respect to the accompanying surface topology of the melt and in turn for governing local mechanisms like absorption, shadowing, boiling, ablation pressure and melt acceleration. The findings can be of importance for understanding the key process mechanisms and for optimizing laser materials processing.

  14. Structural Information Retention in Visual Art Processing.

    Science.gov (United States)

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  15. Structural Information Retention in Visual Art Processing.

    Science.gov (United States)

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  16. Spatiotemporal structure of visual receptive fields in macaque superior colliculus.

    Science.gov (United States)

    Churan, Jan; Guitton, Daniel; Pack, Christopher C

    2012-11-01

    Saccades are useful for directing the high-acuity fovea to visual targets that are of behavioral relevance. The selection of visual targets for eye movements involves the superior colliculus (SC), where many neurons respond to visual stimuli. Many of these neurons are also activated before and during saccades of specific directions and amplitudes. Although the role of the SC in controlling eye movements has been thoroughly examined, far less is known about the nature of the visual responses in this area. We have, therefore, recorded from neurons in the intermediate layers of the macaque SC, while using a sparse-noise mapping procedure to obtain a detailed characterization of the spatiotemporal structure of visual receptive fields. We find that SC responses to flashed visual stimuli start roughly 50 ms after the onset of the stimulus and last for on average ~70 ms. About 50% of these neurons are strongly suppressed by visual stimuli flashed at certain locations flanking the excitatory center, and the spatiotemporal pattern of suppression exerts a predictable influence on the timing of saccades. This suppression may, therefore, contribute to the filtering of distractor stimuli during target selection. We also find that saccades affect the processing of visual stimuli by SC neurons in a manner that is quite similar to the saccadic suppression and postsaccadic enhancement that has been observed in the cortex and in perception. However, in contrast to what has been observed in the cortex, decreased visual sensitivity was generally associated with increased firing rates, while increased sensitivity was associated with decreased firing rates. Overall, these results suggest that the processing of visual stimuli by SC receptive fields can influence oculomotor behavior and that oculomotor signals originating in the SC can shape perisaccadic visual perception.

  17. Structural Integrity Inspection and Visualization System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the successful feasibility demonstration in Phase I, Physical Optics Corporation (POC) proposes to continue the development of a novel Structural Integrity...

  18. Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception

    Directory of Open Access Journals (Sweden)

    Yi-Huang Su

    2016-01-01

    Full Text Available Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance.

  19. Reinforcing Visual Grouping Cues to Communicate Complex Informational Structure.

    Science.gov (United States)

    Bae, Juhee; Watson, Benjamin

    2014-12-01

    In his book Multimedia Learning [7], Richard Mayer asserts that viewers learn best from imagery that provides them with cues to help them organize new information into the correct knowledge structures. Designers have long been exploiting the Gestalt laws of visual grouping to deliver viewers those cues using visual hierarchy, often communicating structures much more complex than the simple organizations studied in psychological research. Unfortunately, designers are largely practical in their work, and have not paused to build a complex theory of structural communication. If we are to build a tool to help novices create effective and well structured visuals, we need a better understanding of how to create them. Our work takes a first step toward addressing this lack, studying how five of the many grouping cues (proximity, color similarity, common region, connectivity, and alignment) can be effectively combined to communicate structured text and imagery from real world examples. To measure the effectiveness of this structural communication, we applied a digital version of card sorting, a method widely used in anthropology and cognitive science to extract cognitive structures. We then used tree edit distance to measure the difference between perceived and communicated structures. Our most significant findings are: 1) with careful design, complex structure can be communicated clearly; 2) communicating complex structure is best done with multiple reinforcing grouping cues; 3) common region (use of containers such as boxes) is particularly effective at communicating structure; and 4) alignment is a weak structural communicator.

  20. Hierarchical Sets: Analyzing Pangenome Structure through Scalable Set Visualizations

    OpenAIRE

    Pedersen, Thomas Lin

    2017-01-01

    The increase in available microbial genome sequences has resulted in an increase in the size of the pangenomes being analyzed. Current pangenome visualizations are not intended for the pangenome sizes possible today and new approaches are necessary in order to convert the increase in available information to increase in knowledge. As the pangenome data structure is essentially a collection of sets we explore the potential for scalable set visualization as a tool for pangenome analysis. We pre...

  1. Structures, composantes et formes spatiales d’un front pionnier situé au Mato Grosso, Brésil

    Directory of Open Access Journals (Sweden)

    Marie Clairay

    2005-04-01

    Full Text Available People have been clearing land since ancient times. Satellite images can now be used to show the spread of the pioneer front and distinguish between pseudo-natural land and cleared land. In Brazil, agricultural colonisation projects play an important role in land use. In Mato Grosso State, remote sensing reveals different agricultural colonisation projects. The aim is to illustrate new spatial forms by observing the spread of cleared land. The limits of cleared land are used as physical identifiers of human territorial occupation. Spatial analysis includes a typology of roads’structures and other basic spatial components that show the participation of each migrant in the advance of the pioneer front. Spatial analysis reveals several forms of spatial occupation.

  2. Structure on Interplanetary Shock Fronts: Type II Radio Burst Source Regions

    CERN Document Server

    Pulupa, M

    2007-01-01

    We present \\emph{in situ} observations of the source regions of interplanetary (IP) type II radio bursts, using data from the Wind spacecraft during the period 1996-2002. We show the results of this survey as well as in-depth analysis of several individual events. Each event analyzed in detail is associated with an interplanetary coronal mass ejection (ICME) and an IP shock driven by the ICME. Immediately prior to the arrival of each shock, electron beams along the interplanetary magnetic field (IMF) and associated Langmuir waves are detected, implying magnetic connection to a quasiperpendicular shock front acceleration site. These observations are analogous to those made in the terrestrial foreshock region, indicating that a similar foreshock region exists on IP shock fronts. The analogy suggests that the electron acceleration process is a fast Fermi process, and this suggestion is borne out by loss cone features in the electron distribution functions. The presence of a foreshock region requires nonplanar st...

  3. Electromagnetic structure and weak decay of meson K in a light-front QCD-inspired

    CERN Document Server

    Pereira, Fabiano P; Frederico, T; Tomio, Lauro

    2007-01-01

    The kaon electromagnetic (e.m.) form factor is reviewed considering a light-front constituent quark model. In this approach, it is discussed the relevance of the quark-antiquark pair terms for the full covariance of the e.m. current. It is also verified, by considering a QCD dynamical model, that a good agreement with experimental data can be obtained for the kaon weak decay constant once a probability of about 80% of the valence component is taken into account.

  4. CHEMTAX-derived phytoplankton community structure associated with temperature fronts in the northeastern Arabian Sea..

    Digital Repository Service at National Institute of Oceanography (India)

    Roy, R.; Chitari, R.; Kulkarni, V.; Krishna, M.S.; Sarma, V.V.S.S.; Anil, A.C.

    and filaments) have chemical and biological manifestations (Brink et al., 1998; Belkin et al., 2009; Read et al., 2000) and are thought to be hotspots for phytoplankton blooms (Hesse et al., 1989, Franks et al., 1992). The Indian National Centre for Ocean...., Barton, E D., Pilling, I., 1993. Development, persistence, and variability of upwelling filaments off the Atlantic coast of the Iberian Peninsula. J. Geophys. Res. 98, 22681-22692. Hesse, KJ., Liu, Z L., Schaumann, K., 1989. Phytoplankton and fronts...

  5. Light-front holography and superconformal quantum mechanics: A new approach to hadron structure and color confinement

    Science.gov (United States)

    Brodsky, Stanley J.; Deur, Alexandre; de Téramond, Guy F.; Dosch, Hans Günter

    2015-11-01

    A primary question in hadron physics is how the mass scale for hadrons consisting of light quarks, such as the proton, emerges from the QCD Lagrangian even in the limit of zero quark mass. If one requires the effective action which underlies the QCD Lagrangian to remain conformally invariant and extends the formalism of de Alfaro, Fubini and Furlan to light-front Hamiltonian theory, then a unique, color-confining potential with a mass parameter κ emerges. The actual value of the parameter κ is not set by the model - only ratios of hadron masses and other hadronic mass scales are predicted. The result is a nonperturbative, relativistic light-front quantum mechanical wave equation, the Light-Front Schrödinger Equation which incorporates color confinement and other essential spectroscopic and dynamical features of hadron physics, including a massless pion for zero quark mass and linear Regge trajectories with the identical slope in the radial quantum number n and orbital angular momentum L. The same light-front equations for mesons with spin J also can be derived from the holographic mapping to QCD (3+1) at fixed light-front time from the soft-wall model modification of AdS5 space with a specific dilaton profile. Light-front holography thus provides a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. One can also extend the analysis to baryons using superconformal algebra - 2 × 2 supersymmetric representations of the conformal group. The resulting fermionic LF bound-state equations predict striking similarities between the meson and baryon spectra. In fact, the holographic QCD light-front Hamiltonians for the states on the meson and baryon trajectories are identical if one shifts the internal angular momenta of the meson (LM) and baryon (LB) by one unit: LM = LB + 1. We also show how the mass scale κ

  6. Pacing Visual Attention: Temporal Structure Effects

    Science.gov (United States)

    1993-06-01

    contracted to correspondingly change resolving power. Finally, the third class of models are the gradient models of attention (e.g., Downing & Pinker ...337. Downing, C.J. & Pinker , S. (1985). The spatial structure of attention. In M.J. Posner and O.S. Manin (Eds) Attention and Performance XI. Hillsdale...R.C. Atkinson, R.J. Herrnstein, G. Lindzey, & R. D. Luce (Eds) Stevens ’ handbook of experimental psychology, volume 2: Learning and cognition. New

  7. Structure of attention and the logic of visual composition.

    Science.gov (United States)

    Wright, Katherine Blair; Bafna, Sonit

    2014-09-01

    Two groups of subjects were presented with two façade designs, one with the front façade of the existing Atlanta Public Library, an exercise in modern abstract plastic composition by the Bauhaus-trained architect Marcel Breuer, and the other with alteration that toned down its plasticity and enhanced simple relations of its parts like symmetry and repetition. The subjects were asked to recall and copy the façades. The results showed that while significantly more students recalled elements of the altered façade, the performance was equivocal for the façades for the copying task. However, the copying task showed the subjects making greater errors in reproducing elements and relations on the periphery, and those that reflect a reading of depth in the façades. We present an account of the experiment, making the case that the results show the influence of visual design of the façade on the way that an interested and involved viewer attends to it in the course of parsing and comprehending it. The broader implication of this point is to see the visual design of buildings not as simple means to increase its aesthetic value, but as a sophisticated means to lead the viewer to specific forms of imaginative engagement.

  8. Structure of Attention and the Logic of Visual Composition

    Directory of Open Access Journals (Sweden)

    Katherine Blair Wright

    2014-07-01

    Full Text Available Two groups of subjects were presented with two façade designs, one with the front façade of the existing Atlanta Public Library, an exercise in modern abstract plastic composition by the Bauhaus-trained architect Marcel Breuer, and the other with alteration that toned down its plasticity and enhanced simple relations of its parts like symmetry and repetition. The subjects were asked to recall and copy the façades. The results showed that while significantly more students recalled elements of the altered façade, the performance was equivocal for the façades for the copying task. However, the copying task showed the subjects making greater errors in reproducing elements and relations on the periphery, and those that reflect a reading of depth in the façades. We present an account of the experiment, making the case that the results show the influence of visual design of the façade on the way that an interested and involved viewer attends to it in the course of parsing and comprehending it. The broader implication of this point is to see the visual design of buildings not as simple means to increase its aesthetic value, but as a sophisticated means to lead the viewer to specific forms of imaginative engagement.

  9. Temporal structure and complexity affect audio-visual correspondence detection

    Directory of Open Access Journals (Sweden)

    Rachel N Denison

    2013-01-01

    Full Text Available Synchrony between events in different senses has long been considered the critical temporal cue for multisensory integration. Here, using rapid streams of auditory and visual events, we demonstrate how humans can use temporal structure (rather than mere temporal coincidence to detect multisensory relatedness. We find psychophysically that participants can detect matching auditory and visual streams via shared temporal structure for crossmodal lags of up to 200 ms. Performance on this task reproduced features of past findings based on explicit timing judgments but did not show any special advantage for perfectly synchronous streams. Importantly, the complexity of temporal patterns influences sensitivity to correspondence. Stochastic, irregular streams – with richer temporal pattern information – led to higher audio-visual matching sensitivity than predictable, rhythmic streams. Our results reveal that temporal structure and its complexity are key determinants for human detection of audio-visual correspondence. The distinctive emphasis of our new paradigms on temporal patterning could be useful for studying special populations with suspected abnormalities in audio-visual temporal perception and multisensory integration.

  10. Differences in hydraulic pressure producing efficiency of front suspension units for motorcycles due to structural difference

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, Tsutomu; Namazue, Eitaro; Ueno, Yutaka

    1995-12-31

    The front suspension unit for motorcycles is one of the functional parts for which continuous engineering improvement is required for advanced driveability. Especially, the ones for off-road motocross racing are frequently required to have their energy absorbing properties, ability to maintain tire-to-ground contact, driving comfort, etc. to be improved to meet the challenges of the racing courses which include many jumps, to exceed the performance of competitors, and to match the ever-improving performance of the engines and frames. To cope with the situation, the operability, rigidity and hydraulic pressure producing mechanism needs to be upgraded. As part of an improvement program, the authors have developed a air-oil separated front suspension which the authors have called the ``twin chamber`` suspension. In this study, the authors compared the hydraulic pressure producing efficiency of the air-oil separated suspension with that of the conventional single chamber construction. The results of the comparison showed that the twin chamber suspension is less affected by the pressure hysteresis by 8% or more at the piston area and 50% or more at the partition area than the conventional suspension. In addition, for the twin chamber suspension, the rise of pressure becomes smoother to give a quicker response as the velocity increases.

  11. DSSR-enhanced visualization of nucleic acid structures in Jmol.

    Science.gov (United States)

    Hanson, Robert M; Lu, Xiang-Jun

    2017-05-03

    Sophisticated and interactive visualizations are essential for making sense of the intricate 3D structures of macromolecules. For proteins, secondary structural components are routinely featured in molecular graphics visualizations. However, the field of RNA structural bioinformatics is still lagging behind; for example, current molecular graphics tools lack built-in support even for base pairs, double helices, or hairpin loops. DSSR (Dissecting the Spatial Structure of RNA) is an integrated and automated command-line tool for the analysis and annotation of RNA tertiary structures. It calculates a comprehensive and unique set of features for characterizing RNA, as well as DNA structures. Jmol is a widely used, open-source Java viewer for 3D structures, with a powerful scripting language. JSmol, its reincarnation based on native JavaScript, has a predominant position in the post Java-applet era for web-based visualization of molecular structures. The DSSR-Jmol integration presented here makes salient features of DSSR readily accessible, either via the Java-based Jmol application itself, or its HTML5-based equivalent, JSmol. The DSSR web service accepts 3D coordinate files (in mmCIF or PDB format) initiated from a Jmol or JSmol session and returns DSSR-derived structural features in JSON format. This seamless combination of DSSR and Jmol/JSmol brings the molecular graphics of 3D RNA structures to a similar level as that for proteins, and enables a much deeper analysis of structural characteristics. It fills a gap in RNA structural bioinformatics, and is freely accessible (via the Jmol application or the JSmol-based website http://jmol.x3dna.org). © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. Hierarchical Sets: Analyzing Pangenome Structure through Scalable Set Visualizations

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin

    2017-01-01

    The increase in available microbial genome sequences has resulted in an increase in the size of the pangenomes being analyzed. Current pangenome visualizations are not intended for the pangenome sizes possible today and new approaches are necessary in order to convert the increase in available...... information to increase in knowledge. As the pangenome data structure is essentially a collection of sets we explore the potential for scalable set visualization as a tool for pangenome analysis. We present a new hierarchical clustering algorithm based on set arithmetics that optimizes the intersection sizes...... along the branches. The intersection and union sizes along the hierarchy are visualized using a composite dendrogram and icicle plot, which, in pangenome context, shows the evolution of pangenome and core size along the evolutionary hierarchy. Outlying elements, i.e. elements whose presence pattern do...

  13. Visualization

    OpenAIRE

    Balon, Andreja

    1990-01-01

    The present thesis entails the field of visualization which is divided into visualization along traditional lines and visualization in computer science. As the psychological aspect of image is of vital importance for visualization, it is shortly described in the beginning. Visualization in computer science is divided into three main fields: scientific visualization, program visualization and visual programming. An explanation and examples of approach to applications are given for each field....

  14. Modeling DNA structure and processes through animation and kinesthetic visualizations

    Science.gov (United States)

    Hager, Christine

    There have been many studies regarding the effectiveness of visual aids that go beyond that of static illustrations. Many of these have been concentrated on the effectiveness of visual aids such as animations and models or even non-traditional visual aid activities like role-playing activities. This study focuses on the effectiveness of three different types of visual aids: models, animation, and a role-playing activity. Students used a modeling kit made of Styrofoam balls and toothpicks to construct nucleotides and then bond nucleotides together to form DNA. Next, students created their own animation to depict the processes of DNA replication, transcription, and translation. Finally, students worked in teams to build proteins while acting out the process of translation. Students were given a pre- and post-test that measured their knowledge and comprehension of the four topics mentioned above. Results show that there was a significant gain in the post-test scores when compared to the pre-test scores. This indicates that the incorporated visual aids were effective methods for teaching DNA structure and processes.

  15. MOLVIE: an interactive visualization environment for molecular structures.

    Science.gov (United States)

    Sun, Huandong; Li, Ming; Xu, Ying

    2003-05-01

    A Molecular visualization interactive environment (MOLVIE), is designed to display three-dimensional (3D) structures of molecules and support the structural analysis and research on proteins. The paper presents the features, design considerations and applications of MOLVIE, especially the new functions used to compare the structures of two molecules and view the partial fragment of a molecule. Being developed in JAVA, MOLVIE is platform-independent. Moreover, it may run on a webpage as an applet for remote users. MOLVIE is available at http://www.cs.ucsb.edu/~mli/Bioinf/software/index.html.

  16. How to Optimize the Structure of Agricultural Products in the Context of Reform of the Supply Front?

    Institute of Scientific and Technical Information of China (English)

    Dan YE; Han LIU; Dong LIANG

    2016-01-01

    Based on reform of the supply front,this paper analyzes the main constraints on China’s current structure of agricultural products,including irrational allocation of resources between agricultural products,prominent problems concerning agricultural product quality and safety,disconnection between market demand and agricultural product R&D,and low processing capacity of agricultural products. Based on summing up the experience of the countries with developed agriculture,this paper proposes the path and mechanism for the optimization of structure of agricultural products in China: optimizing resource allocation of agricultural products; improving the quality of agricultural products; enhancing the R&D capacity of agricultural enterprises; promoting the processing and conversion capacity of agricultural products; perfecting the policy support and subsidy mode.

  17. Non-Simultaneous Failure of Ice in Front of Multi-Leg Structures

    Institute of Scientific and Technical Information of China (English)

    史庆增; 黄焱; 宋安; 佟建峰

    2002-01-01

    Because the multi-leg jacket structure is the major type of offshore structures in the Bohai Sea, the study of non-si-multaneous failure of ice on multi-leg structures is important. However, the non-simultaneous failure has not been consid-ered in engineering design until now, obviously resulting in costly design and notable waste. To resolve this problem, thispaper, by means of analysis of experimental data, calculates the coefficient of the non-simultaneous failure for the double-pile structure, the square four-leg structure, the single-line multi-pile structure, and the conical structure, respectively,and provides some reference criteria for engineering design.

  18. Toward mobile 3D visualization for structural biologists.

    Science.gov (United States)

    Tanramluk, Duangrudee; Akavipat, Ruj; Charoensawan, Varodom

    2013-12-01

    Technological advances in crystallography have led to the ever-rapidly increasing number of biomolecular structures deposited in public repertoires. This undoubtedly shifts the bottleneck of structural biology research from obtaining high-quality structures to data analysis and interpretation. The recently available glasses-free autostereoscopic laptop offers an unprecedented opportunity to visualize and study 3D structures using a much more affordable, and for the first time, portable device. Together with a gamepad re-programmed for 3D structure controlling, we describe how the gaming technologies can deliver the output 3D images for high-quality viewing, comparable to that of a passive stereoscopic system, and can give the user more control and flexibility than the conventional controlling setup using only a mouse and a keyboard.

  19. Visualization of small scale structures on high resolution DEMs

    Science.gov (United States)

    Kokalj, Žiga; Zakšek, Klemen; Pehani, Peter; Čotar, Klemen; Oštir, Krištof

    2015-04-01

    Knowledge on the terrain morphology is very important for observation of numerous processes and events and digital elevation models are therefore one of the most important datasets in geographic analyses. Furthermore, recognition of natural and anthropogenic microrelief structures, which can be observed on detailed terrain models derived from aerial laser scanning (lidar) or structure-from-motion photogrammetry, is of paramount importance in many applications. In this paper we thus examine and evaluate methods of raster lidar data visualization for the determination (recognition) of microrelief features and present a series of strategies to assist selecting the preferred visualization of choice for structures of various shapes and sizes, set in varied landscapes. Often the answer is not definite and more frequently a combination of techniques has to be used to map a very diverse landscape. Researchers can only very recently benefit from free software for calculation of advanced visualization techniques. These tools are often difficult to understand, have numerous options that confuse the user, or require and produce non-standard data formats, because they were written for specific purposes. We therefore designed the Relief Visualization Toolbox (RVT) as a free, easy-to-use, standalone application to create visualisations from high-resolution digital elevation data. It is tailored for the very beginners in relief interpretation, but it can also be used by more advanced users in data processing and geographic information systems. It offers a range of techniques, such as simple hillshading and its derivatives, slope gradient, trend removal, positive and negative openness, sky-view factor, and anisotropic sky-view factor. All included methods have been proven to be effective for detection of small scale features and the default settings are optimised to accomplish this task. However, the usability of the tool goes beyond computation for visualization purposes, as sky

  20. The Structure of Cool Flame Fronts of Pentane,Iso—Pentane and Their Mixture

    Institute of Scientific and Technical Information of China (English)

    Z.A.Mansurov; Ch.K.Westbrook; 等

    2000-01-01

    An experimental study of the combustion of two isomers of n-pentane and iso-pertane in laminar cool flames has been carried out.Thrree flames were studied,one with n-pentane,the second with iso-pentane,and the third with an equimolar mixture of the two isomers.Particular attention has been given to the low temperature region ahead of the hot region of the flame and the cool flame chemistry occurring there.A unique experimental facility has been used to provide access to this cool flame region.Comparison are made of the structures of the three flames,with particular attention on the different intermediate species produced and the correlations between the fuel molecule structure and the specific intermediates produced.

  1. Structure of Cool Flame Fronts of Pentane, Iso-Pentane and Their Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Mansurov, Z A; Mironenko, A A; Bodykov, D U; Rakhimetkaliev, K N; Westbrook, C K

    2000-01-11

    An experimental study of the combustion of two isomers of pentane, n-pentane and iso-pentane, in laminar cool flames has been carried out. Three flames were studied, one with n-pentane, the second with iso-pentane, and the third with an equimolar mixture of the two isomers. Particular attention has been given to the low temperature region ahead of the hot region of the flame and the cool flame chemistry occurring there. A unique experimental facility has been used to provide access to this cool flame region. Comparisons are made of the structures of the three flames, with particular attention on the different intermediate species produced and the correlations between the fuel molecule structure and the specific intermediates produced.

  2. Visualizing Transient Low-Populated Structures of RNA

    Science.gov (United States)

    Dethoff, Elizabeth A.; Petzold, Katja; Chugh, Jeetender; Casiano-Negroni, Anette; Al-Hashimi, Hashim M.

    2012-01-01

    The visualization of RNA conformational changes has provided fundamental insights into how regulatory RNAs carry out their biological functions. The RNA structural transitions that have been characterized to date involve long-lived species that can be captured by structure characterization techniques. Here, we report the Nuclear Magnetic Resonance visualization of RNA transitions towards invisible ‘excited states’ (ES), which exist in too little abundance (2–13%) and for too short periods of time (45–250 μs) to allow structural characterization by conventional techniques. Transitions towards ESs result in localized rearrangements in base-pairing that alter building block elements of RNA architecture, including helix-junction-helix motifs and apical loops. The ES can inhibit function by sequestering residues involved in recognition and signaling or promote ATP-independent strand exchange. Thus, RNAs do not adopt a single conformation, but rather exist in rapid equilibrium with alternative ESs, which can be stabilized by cellular cues to affect functional outcomes. PMID:23041928

  3. Identifying and visualizing macromolecular flexibility in structural biology

    Directory of Open Access Journals (Sweden)

    Martina Palamini

    2016-09-01

    Full Text Available Structural biology comprises a variety of tools to obtain atomic resolution data for the investigation of macromolecules. Conventional structural methodologies including crystallography, NMR and electron microscopy often do not provide sufficient details concerning flexibility and dynamics, even though these aspects are critical for the physiological functions of the systems under investigation. However, the increasing complexity of the molecules studied by structural biology (including large macromolecular assemblies, integral membrane proteins, intrinsically disordered systems, and folding intermediates continuously demands in-depth analyses of the roles of flexibility and conformational specificity involved in interactions with ligands and inhibitors. The intrinsic difficulties in capturing often subtle but critical molecular motions in biological systems have restrained the investigation of flexible molecules into a small niche of structural biology. Introduction of massive technological developments over the recent years, which include time-resolved studies, solution X-ray scattering, and new detectors for cryo-electron microscopy, have pushed the limits of structural investigation of flexible systems far beyond traditional approaches of NMR analysis. By integrating these modern methods with powerful biophysical and computational approaches such as generation of ensembles of molecular models and selective particle picking in electron microscopy, more feasible investigations of dynamic systems are now possible. Using some prominent examples from recent literature, we review how current structural biology methods can contribute useful data to accurately visualize flexibility in macromolecular structures and understand its important roles in regulation of biological processes.

  4. From folding to transpressional faulting: the Cenozoic Fusha structural belt in front of the Western Kunlun Orogen, northwestern Tibetan Plateau

    Science.gov (United States)

    Wang, Cong; Cheng, Xiao-Gan; Chen, Han-Lin; Li, Kang; Fan, Xiao-Gen; Wang, Chun-Yang

    2016-07-01

    Fusha structural belt (FSB) is one of the most important tectonic units in front of the Western Kunlun Orogen, northwestern Tibetan Plateau (NW China), in which the Kekeya oil field was discovered in 1971. However, there is no new oil field discovered since then due to the unclarity of the intense and complex Cenozoic deformation in this area. Based on field investigation, seismic interpretation and Continuous Electromagnetic Profile data, we analyze in detail the Cenozoic deformation history, emphasizing on the spatial and temporal variation of the deformation of the FSB in this paper. The result suggests that the FSB was dominated by two deformation events, (1) early (Miocene-early Pliocene) folding event expressed by anticline, with the western segment E-W orienting, while the eastern segment NWW-SEE orienting and (2) later (since late Pliocene) transpressional faulting event that destroyed and divided the earlier anticline into a number of fault blocks. The transpressional faulting caused dextral strike-slip reverse fault, with the dip angles decreasing eastward from ~90° to reserved. Based on the spatial variation of structural characteristics, we propose that the fault block traps and anticline traps in the eastern segment and fault block traps in western segment are favorable for hydrocarbon accumulation.

  5. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    Science.gov (United States)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  6. Visualization and volumetric structures from MR images of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Parvin, B.; Johnston, W.; Robertson, D.

    1994-03-01

    Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from magnetic resonance imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet removes them when the volumetric consistency cannot be verified. Once the segmentation is complete, the 3D surfaces of the brain can be constructed and visualized.

  7. Optimization Design of Vehicle Front Axle Structure Based on ABAQUS and TOSCA%基于ABAQUS与TOSCA的汽车前桥结构优化设计

    Institute of Scientific and Technical Information of China (English)

    马瑞雪; 王欣; 覃祯员; 张科峰

    2012-01-01

    应用ABAQUS软件对汽车前桥进行强度分析,针对车桥强度不足问题,通过TOSCA优化软件对前桥进行拓扑优化设计,在保证承栽能力的前提下有效减轻其重量。%The author analyze the vehicle front axle for the strength by ABAQUS software. In view of the axle strength shortage problem, they use TOSCA optimization software designing the front axle topological optimization structure,in order to effectively reduce its weight under the condition of its bearing capacity.

  8. Seismic structure across the Caledonian Deformation Front along MONA LISA profile 1 in the southeastern North Sea

    Science.gov (United States)

    Abramovitz, Tanni; Thybo, Hans; MONA LISA Working Group

    1998-03-01

    Seismic data from the MONA LISA (Marine and Onshore North Sea Acquisition for Lithospheric Seismic Analysis) project in the southeastern North Sea image the Caledonian Deformation Front (CDF), which is the collisional suture between Baltica to the north and east and Avalonia to the south and west. The NS-trending MONA LISA normal-incidence reflection profile 1 was recorded to 26 s twt. Coincident wide-angle data were acquired on nine ocean bottom hydrophones and several onshore mobile seismographs along and off the profile. The model of compressional seismic velocity shows three different crustal types: (a) a typical three-layered shield-type crust below the Ringkøbing Fyn High to the north: (b) a highly complex transitional crust in the central part; and (c) a two-layered crust of Caledonian origin to the south. Sharp and strong normal-incidence and wide-angle reflections from Moho were recorded south of the Caledonian Deformation Front in contrast to less distinct reflections further north. S-dipping crustal reflections from 4 to 11 s twt over ˜70 km horizontal distance terminate at Moho and coincide with a change in the seismic velocity structure. This indicates northward obduction of Avalonian crust. Non-migrated normal-incidence seismic sections show crossing weak N-dipping and stronger S-dipping reflections to 20 s twt from the uppermost mantle. We propose a tectonic model where the closure of the Tornquist Sea took place along a N-dipping subduction zone which was later overprinted by a late-or post-Caledonian S-dipping shear zone. Sub-Moho velocities are 7.8-7.9 km/s under 34-35-km-thick Baltica crust and 8.1-8.3 km/s under 25-26-km-thick Caledonian crust. The sub-horizontal Moho across the Caledonian collision zone implies late- or post-Caledonian re-equilibration of the seismological Moho. We interpret the low-velocity upper mantle (7.8-8.1 km/s) to the north as former Baltica lower crust in eclogite facies after pressure-induced metamorphism as a

  9. Guidelines for the structure of methodological processes in visual anthropology.

    Science.gov (United States)

    Svilicić, Niksa

    2011-12-01

    Vast majority of visual anthropologists of the 20th century were more focused on general phenomenology of visual anthropology, i.e. the content aspect of their works and their impact on scientific knowledge, leaving behind style of directing and practical principles & processes of creating anthropological film. So far, judging by the available literature, there are no strict guidelines for directorial procedures, nor the precise definition of determining of the methodical processes in production of an anthropological film. Consequently, the goal of this study is to determine the structure and forms of methodical processes as well as to define the advantages and disadvantages of each of them. By using adequate guidelines, the researcher, i.e. the author of the anthropological film, can optimize the production and post-production processes as soon as in preparation (preproduction) period of working on the film, by the technical choice of the approach to the production (proactive/reactive/subjective/objective...) and by defining the style of directing. In other words, it ultimately means more relevant scientific research result with less time and resources.

  10. Feedback strategies for visual search in airframe structural inspection.

    Science.gov (United States)

    Gramopadhye, A K; Drury, C G; Sharit, J

    1997-05-01

    Feedback of information has consistently shown positive results in human inspection, provided it is given in a timely and appropriate manner. Feedback serves as the basis of most training schemes; traditionally this has been performance feedback. Other forms of feedback which provide strategy information rather than performance information may have a role in improving inspection. This study compared performance feedback and cognitive feedback in a realistic simulation of an aircraft structural inspection task. Performance (time, errors) feedback showed the greatest improvements in performance measures. Cognitive feedback enhanced efficiency measures of search strategy. When cognitive feedback consisted of visual representations of the path and the coverage of the search sequence, subjects also were able to use this task information to improve their search performance.

  11. Phytoplankton community structure at the juncture of the Agulhas return front and subtropical front in the Indian Ocean sector of Southern Ocean: Bottom-up and top-down control

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.K.; George, J.V.; Soares, M.A.; Devi, A.; Anilkumar, N.; Roy, R.; Bhaskar, P.V.; Murukesh, N.; Achuthankutty, C.T.

    The juncture of the Agulhas Return Front (ARF) and Subtropical Front (STF) in the Indian Ocean sector of Southern Ocean (SO) is characterized by high mesoscale turbulence, which results in sporadic, short lived phytoplankton proliferation The biota...

  12. Spherical aberration and other higher-order aberrations in the human eye : from summary wave-front analysis data to optical variables relevant to visual perception

    NARCIS (Netherlands)

    Jansonius, Nomdo M.

    2010-01-01

    Wave-front analysis data from the human eye are commonly presented using the aberration coefficient c(4)(0) (primary spherical aberration) together with an overall measure of all higher-order aberrations. If groups of subjects are compared, however, the relevance of an observed difference cannot eas

  13. Abstract numeric relations and the visual structure of algebra.

    Science.gov (United States)

    Landy, David; Brookes, David; Smout, Ryan

    2014-09-01

    Formal algebras are among the most powerful and general mechanisms for expressing quantitative relational statements; yet, even university engineering students, who are relatively proficient with algebraic manipulation, struggle with and often fail to correctly deploy basic aspects of algebraic notation (Clement, 1982). In the cognitive tradition, it has often been assumed that skilled users of these formalisms treat situations in terms of semantic properties encoded in an abstract syntax that governs the use of notation without particular regard to the details of the physical structure of the equation itself (Anderson, 2005; Hegarty, Mayer, & Monk, 1995). We explore how the notational structure of verbal descriptions or algebraic equations (e.g., the spatial proximity of certain words or the visual alignment of numbers and symbols in an equation) plays a role in the process of interpreting or constructing symbolic equations. We propose in particular that construction processes involve an alignment of notational structures across representation systems, biasing reasoners toward the selection of formal notations that maintain the visuospatial structure of source representations. For example, in the statement "There are 5 elephants for every 3 rhinoceroses," the spatial proximity of 5 and elephants and 3 and rhinoceroses will bias reasoners to write the incorrect expression 5E = 3R, because that expression maintains the spatial relationships encoded in the source representation. In 3 experiments, participants constructed equations with given structure, based on story problems with a variety of phrasings. We demonstrate how the notational alignment approach accounts naturally for a variety of previously reported phenomena in equation construction and successfully predicts error patterns that are not accounted for by prior explanations, such as the left to right transcription heuristic.

  14. Visualization of Link Structures and URL Retrievals Utilizing Internal Structure of URLs Based on Brunch and Bound Algorithms

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2012-11-01

    Full Text Available Method for visualization of URL link structure and URL retrievals using internal structure of URLs based on brunch and bound method is proposed. Twisting link structure of URLs can be solved by the proposed visualization method. Also some improvements are observed for the proposed brunch and bound based method in comparison to the conventional URL retrieval methods.

  15. Eye structure, activity rhythms and visually-driven behavior are tuned to visual niche in ants

    Directory of Open Access Journals (Sweden)

    Ayse eYilmaz

    2014-06-01

    Full Text Available Insects have evolved physiological adaptations and behavioural strategies that allow them to cope with a broad spectrum of environmental challenges and contribute to their evolutionary success. Visual performance plays a key role in this success. Correlates between life style and eye organization have been reported in various insect species. Yet, if and how visual ecology translates effectively into different visual discrimination and learning capabilities has been less explored. Here we report results from optical and behavioural analyses performed in two sympatric ant species, Formica cunicularia and Camponotus aethiops. We show that the former are diurnal while the latter are cathemeral. Accordingly, F. cunicularia workers present compound eyes with higher resolution, while C. aethiops workers exhibit eyes with lower resolution but higher sensitivity. The discrimination and learning of visual stimuli differs significantly between these species in controlled dual-choice experiments: discrimination learning of small-field visual stimuli is achieved by F. cunicularia but not by C. aethiops, while both species master the discrimination of large-field visual stimuli. Our work thus provides a paradigmatic example about how timing of foraging activities and visual environment match the organization of compound eyes and visually-driven behaviour. This correspondence underlines the relevance of an ecological/evolutionary framework for analyses in behavioural neuroscience.

  16. Managing Inter-Firm Collaboration in the Fuzzy Front-End: Structure as a Two-Edged Sword

    DEFF Research Database (Denmark)

    Høj Jørgensen, Jacob; Goduscheit, René Chester; Bergenholtz, Carsten

    2011-01-01

    organisations in an innovation network are somewhat neglected in the literature. The aim of this paper is hence to address the challenges that an organisation faces when integrating a plurality of suppliers, customers and other organisations into the Fuzzy Front End of the innovation process....

  17. Code Flows : Visualizing Structural Evolution of Source Code

    NARCIS (Netherlands)

    Telea, Alexandru; Auber, David

    2008-01-01

    Understanding detailed changes done to source code is of great importance in software maintenance. We present Code Flows, a method to visualize the evolution of source code geared to the understanding of fine and mid-level scale changes across several file versions. We enhance an existing visual met

  18. Code flows : Visualizing structural evolution of source code

    NARCIS (Netherlands)

    Telea, Alexandru; Auber, David

    2008-01-01

    Understanding detailed changes done to source code is of great importance in software maintenance. We present Code Flows, a method to visualize the evolution of source code geared to the understanding of fine and mid-level scale changes across several file versions. We enhance an existing visual met

  19. VISUALIZATION APPROACH TO STRUCTURE-FUNCTION RELATIONSHIP IN BIOLOGICAL MACROMOLECULES

    Directory of Open Access Journals (Sweden)

    M. Luetić

    2015-08-01

    Full Text Available Introduction: Most of recent research in the field of education strongly recommends the use of visualization in the daily teacher’s practice, especially when it comes to teaching science. Objectives: We investigated the impact of different kinds of visualization on student’s accomplishments, and the relationship between 2D and 3D visualization on the learning outcomes in biochemistry teaching, as well as gender-related differences in 2D vs 3D perception abilities. Materials and Methods: The research study was conducted on a sample of 149 senior secondary school students, devided into three groups: control group (usual teaching approach, and two experimental groups taught using different kinds of visualization: E1 (2D and 3D static visualization tools, and E2 (3D dynamic visualization tools, in addition. Discussion and results: We measured the students’ learning outcomes in biochemistry, as well as the level of satisfaction with different teaching methods. The data were interpreted by performing statistical measures and analyses. In order to validate our hypothesis, we used one-tail and two-tail ANOVA analyses (along with the t-test.Conclusions: There was no statistical significance regarding 2D vs 3D visualization tools in biochemistry teaching. Although there existed some gender-related differences in students’ achievements (in favor of females, it was not established that they were related to the type of visualization (2D or 3D tools applied. However students from the E2 group (additional computer animations were more interested and involved in this kind of teaching. Although the results do not show a statistical significance in favor of 3D visualization, we must conclude that in teaching biochemistry it is certainly a more efficient approach than traditional teacher-oriented lessons. By using this kind of visualization tools in everyday teaching practice, chemistry teachers are given the opportunity to enlighten students with somewhat

  20. Drawing the Line between Constituent Structure and Coherence Relations in Visual Narratives

    Science.gov (United States)

    Cohn, Neil; Bender, Patrick

    2017-01-01

    Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of visual narrative grammar posits that hierarchic "grammatical" structures operate at the…

  1. Visualizing High-Dimensional Structures by Dimension Ordering and Filtering using Subspace Analysis

    NARCIS (Netherlands)

    Ferdosi, Bilkis J.; Roerdink, Jos B. T. M.

    2011-01-01

    High-dimensional data visualization is receiving increasing interest because of the growing abundance of high-dimensional datasets. To understand such datasets, visualization of the structures present in the data, such as clusters, can be an invaluable tool. Structures may be present in the full hig

  2. Visual salience modulates structure choice in relative clause production.

    Science.gov (United States)

    Montag, Jessica L; MacDonald, Maryellen C

    2014-06-01

    The role of visual salience on utterance form was investigated in a picture description study. Participants heard spoken questions about animate or inanimate entities in a picture and produced a relative clause in response. Visual properties of the scenes affected production choices such that less salient inanimate entities tended to yield longer initiation latencies and to be described with passive relative clauses more than visually salient inanimates. We suggest that the participants' question-answering task can change as a function of visual salience of entities in the picture. Less salient entities require a longer visual search of the scene, which causes the speaker to notice or attend more to the non-target competitors in the picture. As a result, it becomes more important in answering the question for the speaker to contrast the target item with a salient competitor. This effect is different from other effects of visual salience, which tend to find that more salient entities take more prominent grammatical roles in the sentence. We interpret this discrepancy as evidence that visual salience does not have a single effect on sentence production, but rather its effect is modulated by task and linguistic context.

  3. Substrate-Guided Front-Face Reaction Revealed by Combined Structural Snapshots and Metadynamics for the Polypeptide N-Acetylgalactosaminyltransferase 2

    DEFF Research Database (Denmark)

    Lira-Navarrete, Erandi; Iglesias-Fernández, Javier; Zandberg, Wesley F

    2014-01-01

    of structural snapshots of the enzyme during the catalytic cycle and combine these with quantum-mechanics/molecular-mechanics (QM/MM) metadynamics to unravel the catalytic mechanism of this retaining enzyme at the atomic-electronic level of detail. Our study provides a detailed structural rationale...... for an ordered bi-bi kinetic mechanism and reveals critical aspects of substrate recognition, which dictate the specificity for acceptor Thr versus Ser residues and enforce a front-face SN i-type reaction in which the substrate N-acetyl sugar substituent coordinates efficient glycosyl transfer....

  4. Light-Front Holography and Superconformal Quantum Mechanics: A New Approach to Hadron Structure and Color Confinement

    CERN Document Server

    Brodsky, S J; de Teramond, G F; Dosch, H G

    2015-01-01

    A primary question in hadron physics is how the mass scale for hadrons consisting of light quarks, such as the proton, emerges from the QCD Lagrangian even in the limit of zero quark mass. If one requires the effective action which underlies the QCD Lagrangian to remain conformally invariant and extends the formalism of de Alfaro, Fubini and Furlan to light-front Hamiltonian theory, then a unique, color-confining potential with a mass parameter $\\kappa$ emerges. The actual value of the parameter $\\kappa$ is not set by the model - only ratios of hadron masses and other hadronic mass scales are predicted. The result is a nonperturbative, relativistic light-front quantum mechanical wave equation, the Light-Front Schr\\"odinger Equation which incorporates color confinement and other essential spectroscopic and dynamical features of hadron physics, including a massless pion for zero quark mass and linear Regge trajectories with the identical slope in the radial quantum number $n$ and orbital angular momentum $L$. T...

  5. A structured model of video reproduces primary visual cortical organisation.

    Directory of Open Access Journals (Sweden)

    Pietro Berkes

    2009-09-01

    Full Text Available The visual system must learn to infer the presence of objects and features in the world from the images it encounters, and as such it must, either implicitly or explicitly, model the way these elements interact to create the image. Do the response properties of cells in the mammalian visual system reflect this constraint? To address this question, we constructed a probabilistic model in which the identity and attributes of simple visual elements were represented explicitly and learnt the parameters of this model from unparsed, natural video sequences. After learning, the behaviour and grouping of variables in the probabilistic model corresponded closely to functional and anatomical properties of simple and complex cells in the primary visual cortex (V1. In particular, feature identity variables were activated in a way that resembled the activity of complex cells, while feature attribute variables responded much like simple cells. Furthermore, the grouping of the attributes within the model closely parallelled the reported anatomical grouping of simple cells in cat V1. Thus, this generative model makes explicit an interpretation of complex and simple cells as elements in the segmentation of a visual scene into basic independent features, along with a parametrisation of their moment-by-moment appearances. We speculate that such a segmentation may form the initial stage of a hierarchical system that progressively separates the identity and appearance of more articulated visual elements, culminating in view-invariant object recognition.

  6. Functional and structural connectivity of the visual system in infants with perinatal brain injury.

    Science.gov (United States)

    Merhar, Stephanie L; Gozdas, Elveda; Tkach, Jean A; Harpster, Karen L; Schwartz, Terry L; Yuan, Weihong; Kline-Fath, Beth M; Leach, James L; Altaye, Mekibib; Holland, Scott K

    2016-07-01

    Infants with perinatal brain injury are at risk of later visual problems. Advanced neuroimaging techniques show promise to detect functional and structural alterations of the visual system. We hypothesized that infants with perinatal brain injury would have less brain activation during a visual functional magnetic resonance imaging (fMRI) task and reduced task-based functional connectivity and structural connectivity as compared with healthy controls. Ten infants with perinatal brain injury and 20 control infants underwent visual fMRI and diffusion tensor imaging (DTI) during natural sleep with no sedation. Activation maps, functional connectivity maps, and structural connectivity were analyzed and compared between the two groups. Most infants in both groups had negative activation in the visual cortex during the fMRI task. Infants with brain injury showed reduced activation in the occipital cortex, weaker connectivity between visual areas and other areas of the brain during the visual task, and reduced fractional anisotropy in white matter tracts projecting to visual regions, as compared with control infants. Infants with brain injury sustained in the perinatal period showed evidence of decreased brain activity and functional connectivity during a visual task and altered structural connectivity as compared with healthy term neonates.

  7. Strength through structure: visualization and local assessment of the trabecular bone structure

    Energy Technology Data Exchange (ETDEWEB)

    Raeth, C; Monetti, R; Bauer, J; Sidorenko, I [Max-Planck Institut fuer Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching (Germany); Mueller, D [Department of Radiology, Technische Universitaet Muenchen, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675 Munich (Germany); Matsuura, M [Institute of Anatomy, Ludwig Maximilians Universitaet Muenchen, Pettenkoferstrasse 11, 80336 Muenchen (Germany); Lochmueller, E-M [Department of Gynaecology I, Ludwig Maximilians Universitaet Muenchen, Maistrasse 11, 80337 Muenchen (Germany); Zysset, P [Institute for Lightweight Design and Structural Biomechanics, Vienna University of Technology (TU-Wien), Gusshausstrasse 27-29, 1040 Wien (Austria); Eckstein, F [Paracelsus Medical University Salzburg, Strubergasse 21, 5020 Salzburg (Austria)], E-mail: cwr@mpe.mpg.de

    2008-12-15

    The visualization and subsequent assessment of the inner human bone structures play an important role for better understanding the disease- or drug-induced changes of bone in the context of osteoporosis giving prospect for better predictions of bone strength and thus of the fracture risk of osteoporotic patients. In this work, we show how the complex trabecular bone structure can be visualized using {mu}CT imaging techniques at an isotropic resolution of 26 {mu}m. We quantify these structures by calculating global and local topological and morphological measures, namely Minkowski functionals (MFs) and utilizing the (an-)isotropic scaling index method (SIM) and by deriving suitable texture measures based on MF and SIM. Using a sample of 151 specimens taken from human vertebrae in vitro, we correlate the texture measures with the mechanically measured maximum compressive strength (MCS), which quantifies the strength of the bone probe, by using Pearson's correlation coefficient. The structure parameters derived from the local measures yield good correlations with the bone strength as measured in mechanical tests. We investigate whether the performance of the texture measures depends on the MCS value by selecting different subsamples according to MCS. Considering the whole sample the results for the newly defined parameters are better than those obtained for the standard global histomorphometric parameters except for bone volume/total volume (BV/TV). If a subsample consisting only of weak bones is analysed, the local structural analysis leads to similar and even better correlations with MCS as compared to BV/TV. Thus, the MF and SIM yield additional information about the stability of the bone especially in the case of weak bones, which corroborates the hypothesis that the bone structure (and not only its mineral mass) constitutes an important component of bone stability.

  8. Electromagnetic structure and weak decay of pseudoscalar mesons in a light-front QCD-inspired model

    CERN Document Server

    Salcedo, L A M; Hadj-Michef, D; Frederico, T

    2006-01-01

    We study the scaling of the $^3S_1-^1S_0$ meson mass splitting and the pseudoscalar weak decay constants with the mass of the meson, as seen in the available experimental data. We use an effective light-front QCD-inspired dynamical model regulated at short-distances to describe the valence component of the pseudoscalar mesons. The experimentally known values of the mass splittings, decay constants (from global lattice-QCD averages) and the pion charge form factor up to 4 [GeV/c]$^2$ are reasonably described by the model

  9. Transverse tectonic structural elements across Himalayan mountain front, eastern Arunachal Himalaya, India: Implication of superposed landform development on analysis of neotectonics

    Science.gov (United States)

    Bhakuni, S. S.; Luirei, Khayingshing; Kothyari, Girish Ch.; Imsong, Watinaro

    2017-04-01

    Structural and morphotectonic signatures in conjunction with the geomorphic indices are synthesised to trace the role of transverse tectonic features in shaping the landforms developed along the frontal part of the eastern Arunachal sub-Himalaya. Mountain front sinuosity (Smf) index values close to one are indicative of the active nature of the mountain front all along the eastern Arunachal Himalaya, which can be directly attributed to the regional uplift along the Himalayan Frontal Thrust (HFT). However, the mountain front is significantly sinusoidal around junctions between HFT/MBT (Main Boundary Thrust) and active transverse faults. The high values of stream length gradient (SL) and stream steepness (Ks) indices together with field evidence of fault scarps, offset of terraces, and deflection of streams are markers of neotectonic uplift along the thrusts and transverse faults. This reactivation of transverse faults has given rise to extensional basins leading to widening of the river courses, providing favourable sites for deposition of recent sediments. Tectonic interactions of these transverse faults with the Himalayan longitudinal thrusts (MBT/HFT) have segmented the mountain front marked with varying sinuosity. The net result is that a variety of tectonic landforms recognized along the mountain front can be tracked to the complex interactions among the transverse and longitudinal tectonic elements. Some distinctive examples are: in the eastern extremity of NE Himalaya across the Dibang River valley, the NW-SE trending mountain front is attenuated by the active Mishmi Thrust that has thrust the Mishmi crystalline complex directly over the alluvium of the Brahmaputra plains. The junction of the folded HFT and Mishmi Thrust shows a zone of brecciated and pulverized rocks along which transverse axial planar fracture cleavages exhibit neotectonic activities in a transverse fault zone coinciding with the Dibang River course. Similarly, the transverse faults cut the

  10. Subregional structural and connectivity damage in the visual cortex in neuromyelitis optica

    Science.gov (United States)

    Cai, Huanhuan; Zhu, Jiajia; Zhang, Ningnannan; Wang, Qiuhui; Zhang, Chao; Yang, Chunsheng; Sun, Jie; Sun, Xianting; Yang, Li; Yu, Chunshui

    2017-01-01

    Patients with neuromyelitis optica (NMO) have shown structural and functional impairments in the visual cortex. We aimed to characterize subregional grey matter volume (GMV) and resting-state functional connectivity (rsFC) changes in the visual cortex in NMO. Thirty-seven NMO patients and forty-two controls underwent structural and functional MRI scans. The GMV and rsFC of each visual subregion were compared between the groups. Compared with controls, NMO patients had GMV reductions in the bilateral V1, V2, V3d, VP, and LO and in the left V3A. In canonical visual pathways, the relatively low-level subregions showed more significant GMV reductions than did the high-level ones. Regardless of GMV correction, NMO patients showed reduced rsFC in the bilateral LO and V4v and in the left V2. The GMVs of the bilateral V1 and LO and of the left V2 and V3d were negatively correlated with clinical disability in NMO patients; these correlation coefficients were associated with hierarchical positions in the visual pathways. These findings suggest that in NMO, the low-level visual subregions have more severe structural damage; structural damage is not the only factor affecting rsFC alterations of visual subregions; GMV reduction in the low-level visual subregions has the highest predictive value for clinical disability. PMID:28157198

  11. Drawing the Line Between Constituent Structure and Coherence Relations in Visual Narratives

    NARCIS (Netherlands)

    Cohn, Neil; Bender, Patrick

    2017-01-01

    Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of visual narrative grammar posits that hierarchic "gramm

  12. The impact of structural and functional parameters in glaucoma patients on patient-reported visual functioning.

    Directory of Open Access Journals (Sweden)

    Christoph Hirneiß

    Full Text Available BACKGROUND: To evaluate the impact of structural changes of the retinal nerve fiber layer (RNFL, and visual field loss, on functional impairment assessed by patient-reported visual functioning in glaucoma. METHODS: Patients with glaucomatous optic nerve damage were enrolled in this cross-sectional study. Peripapillary RNFL thickness was obtained with spectral-domain optical coherence tomography (SD-OCT. Function was assessed by patient-reported visual functioning using the Rasch-calibrated Glaucoma Activity Limitation 9 (GAL-9 questionnaire and standard automated perimetry. The impact of peripapillary RNFL loss on functional impairment was analyzed with correlation and linear regression analyses. RESULTS: A total of 176 eyes from 88 glaucoma patients were included. The SD-OCT assessed temporal-superior and temporal-inferior RNFL sector of the worse eye revealed significant correlation with the GAL-9 scores (r=-0.298, p=0.011 and r=-0.251, p=0.033, respectively. In mutivariate regression analysis, the best predictors for patient-reported visual functioning were visual acuity of the better eye and mean defect of the worse eye (R(2=0.334, while structural parameters could not enhance the prediction of GAL-9 scores. CONCLUSIONS: Self-reported visual functioning of patients with glaucoma is better predicted by visual performance data than structural parameters. However, some structural changes of the worse eye are significantly correlated with patient-reported visual functioning.

  13. Visual exploration of program structure, dependencies and metrics with SolidSX

    NARCIS (Netherlands)

    Reniers, Dennie; Voinea, Lucian; Telea, Alexandru

    2011-01-01

    We present SolidSX, an visual analysis tool for code structure, dependencies, and metrics. Our tool facilitates the understanding of large program code bases by simplifying the entire pipeline from data acquisition up to visualization and interactive querying. Secondly, SolidSX is an easy to use,

  14. WebStruct and VisualStruct: Web interfaces and visualization for Structure software implemented in a cluster environment.

    Science.gov (United States)

    Jayashree, B; Rajgopal, S; Hoisington, D; Prasanth, V P; Chandra, S

    2008-09-24

    Structure, is a widely used software tool to investigate population genetic structure with multi-locus genotyping data. The software uses an iterative algorithm to group individuals into "K" clusters, representing possibly K genetically distinct subpopulations. The serial implementation of this programme is processor-intensive even with small datasets. We describe an implementation of the program within a parallel framework. Speedup was achieved by running different replicates and values of K on each node of the cluster. A web-based user-oriented GUI has been implemented in PHP, through which the user can specify input parameters for the programme. The number of processors to be used can be specified in the background command. A web-based visualization tool "Visualstruct", written in PHP (HTML and Java script embedded), allows for the graphical display of population clusters output from Structure, where each individual may be visualized as a line segment with K colors defining its possible genomic composition with respect to the K genetic sub-populations. The advantage over available programs is in the increased number of individuals that can be visualized. The analyses of real datasets indicate a speedup of up to four, when comparing the speed of execution on clusters of eight processors with the speed of execution on one desktop. The software package is freely available to interested users upon request.

  15. A review of visual memory capacity: Beyond individual items and toward structured representations

    National Research Council Canada - National Science Library

    Brady, Timothy F; Konkle, Talia; Alvarez, George A

    2011-01-01

    .... Recent research on visual memory has shifted toward a representation-based emphasis, focusing on the contents of memory and attempting to determine the format and structure of remembered information...

  16. Changes in the distribution of sustained attention alter the perceived structure of visual space.

    Science.gov (United States)

    Fortenbaugh, Francesca C; Robertson, Lynn C; Esterman, Michael

    2017-02-01

    Visual spatial attention is a critical process that allows for the selection and enhanced processing of relevant objects and locations. While studies have shown attentional modulations of perceived location and the representation of distance information across multiple objects, there remains disagreement regarding what influence spatial attention has on the underlying structure of visual space. The present study utilized a method of magnitude estimation in which participants must judge the location of briefly presented targets within the boundaries of their individual visual fields in the absence of any other objects or boundaries. Spatial uncertainty of target locations was used to assess perceived locations across distributed and focused attention conditions without the use of external stimuli, such as visual cues. Across two experiments we tested locations along the cardinal and 45° oblique axes. We demonstrate that focusing attention within a region of space can expand the perceived size of visual space; even in cases where doing so makes performance less accurate. Moreover, the results of the present studies show that when fixation is actively maintained, focusing attention along a visual axis leads to an asymmetrical stretching of visual space that is predominantly focused across the central half of the visual field, consistent with an expansive gradient along the focus of voluntary attention. These results demonstrate that focusing sustained attention peripherally during active fixation leads to an asymmetrical expansion of visual space within the central visual field.

  17. Visualization of Three-Dimensional Nephron Structure With Microcomputed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bentley,M.; Jorgensen, S.; Lerman, L.; Ritman, E.; Romero, J.

    2007-01-01

    The three-dimensional architecture of nephrons in situ and their interrelationship with other nephrons are difficult to visualize by microscopic methods. The present study uses microcomputed X-ray tomography (micro-CT) to visualize intact nephrons in situ. Rat kidneys were perfusion-fixed with buffered formalin and their vasculature was subsequently perfused with radiopaque silicone. Cortical tissue was stained en bloc with osmium tetroxide, embedded in plastic, scanned, and reconstructed at voxel resolutions of 6, 2, and 1 {mu}m. At 6 {mu}m resolution, large blood vessels and glomeruli could be visualized but nephrons and their lumens were small and difficult to visualize. Optimal images were obtained using a synchrotron radiation source at 2 {mu}m resolution where nephron components could be identified, correlated with histological sections, and traced. Proximal tubules had large diameters and opaque walls, whereas distal tubules, connecting tubules, and collecting ducts had smaller diameters and less opaque walls. Blood vessels could be distinguished from nephrons by the luminal presence of radiopaque silicone. Proximal tubules were three times longer than distal tubules. Proximal and distal tubules were tightly coiled in the outer cortex but were loosely coiled in the middle and inner cortex. The connecting tubules had the narrowest diameters of the tubules and converged to form arcades that paralleled the radial vessels as they extended to the outer cortex. These results illustrate a potential use of micro-CT to obtain three-dimensional information about nephron architecture and nephron interrelationships, which could be useful in evaluating experimental tubular hypertrophy, atrophy, and necrosis.

  18. Visualization of three-dimensional nephron structure with microcomputed tomography.

    Science.gov (United States)

    Bentley, Michael D; Jorgensen, Steven M; Lerman, Lilach O; Ritman, Erik L; Romero, J Carlos

    2007-03-01

    The three-dimensional architecture of nephrons in situ and their interrelationship with other nephrons are difficult to visualize by microscopic methods. The present study uses microcomputed X-ray tomography (micro-CT) to visualize intact nephrons in situ. Rat kidneys were perfusion-fixed with buffered formalin and their vasculature was subsequently perfused with radiopaque silicone. Cortical tissue was stained en bloc with osmium tetroxide, embedded in plastic, scanned, and reconstructed at voxel resolutions of 6, 2, and 1 microm. At 6 microm resolution, large blood vessels and glomeruli could be visualized but nephrons and their lumens were small and difficult to visualize. Optimal images were obtained using a synchrotron radiation source at 2 microm resolution where nephron components could be identified, correlated with histological sections, and traced. Proximal tubules had large diameters and opaque walls, whereas distal tubules, connecting tubules, and collecting ducts had smaller diameters and less opaque walls. Blood vessels could be distinguished from nephrons by the luminal presence of radiopaque silicone. Proximal tubules were three times longer than distal tubules. Proximal and distal tubules were tightly coiled in the outer cortex but were loosely coiled in the middle and inner cortex. The connecting tubules had the narrowest diameters of the tubules and converged to form arcades that paralleled the radial vessels as they extended to the outer cortex. These results illustrate a potential use of micro-CT to obtain three-dimensional information about nephron architecture and nephron interrelationships, which could be useful in evaluating experimental tubular hypertrophy, atrophy, and necrosis.

  19. [Visual representation of biological structures in teaching material].

    Science.gov (United States)

    Morato, M A; Struchiner, M; Bordoni, E; Ricciardi, R M

    1998-01-01

    Parameters must be defined for presenting and handling scientific information presented in the form of teaching materials. Through library research and consultations with specialists in the health sciences and in graphic arts and design, this study undertook a comparative description of the first examples of scientific illustrations of anatomy and the evolution of visual representations of knowledge on the cell. The study includes significant examples of illustrations which served as elements of analysis.

  20. Managing Inter-Firm Collaboration in the Fuzzy Front-End: Structure as a Two-Edged Sword

    DEFF Research Database (Denmark)

    Høj Jørgensen, Jacob; Goduscheit, René Chester; Bergenholtz, Carsten

    2011-01-01

    Literature on innovation emphasises the potential for organisations to collaborate and network instead of carrying out innovation individually. Integrating suppliers, customers and other organisations into the innovation process is perceived as a key to success in innovation management (Chesbrough...... organisations in an innovation network are somewhat neglected in the literature. The aim of this paper is hence to address the challenges that an organisation faces when integrating a plurality of suppliers, customers and other organisations into the Fuzzy Front End of the innovation process......., 2003). Furthermore, the management of the initial phase of the innovation process has proven vital to the overall innovation success (Kim and Wilemon, 2002b,a). Although the merits of network-based innovations are widely acknowledged, the managerial challenges of the initial integration of external...

  1. Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention

    OpenAIRE

    Nielsen, Simon; Wilms, L. Inge

    2015-01-01

    We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60–75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path a...

  2. Front Matter.

    Science.gov (United States)

    2015-01-01

    This book has been written by a group of renowned and experienced international researchers from nine countries, who share here how they have applied Techno-Anthropological methodologies to their research in a variety of different health informatics contexts. Bridges have been built in the process of editing and writing this book, and we are now actually building Techno-Anthropological research constructions in research environments in Denmark, Australia, Canada, Finland and Israel. This is the third major work on Techno-Anthropology, following What is Techno-Anthropology? (2013) edited by Tom Børsen and Lars Botin and a special issue on Techno-Anthropology in Techné: Journal of the Society for Philosophy and Technology - edited by Galit Wellner, Lars Botin and Kathrin Otrel-Cass (2015). In this current volume we specifically address methodology from ethnographic, anthropological, ethical, sociotechnical and participatory perspectives in a health informatics context, which is reflected in the structure of the anthology. Techno-Anthropology is an emerging interdisciplinary research field that focuses on human/technology interactions and relations, and on how these can be understood and facilitated in context. This means that Techno-Anthropology has much to offer the health informatics and eHealth contexts when it comes to applying methods and techniques that can create an understanding of how citizens, patients, health care professionals, IT-professionals - and those who manage them - interact with technology. Techno-Anthropology, in its current configuration, also considers how technological innovation, development and implementation can be made in an appropriate and pragmatic way in relation to understanding work practices and in interpretations of technology in situated and contextual transfers of knowledge in constant negotiations. This means that there is a striving towards connecting science, engineering, social science and the humanities. The conglomeration

  3. Structural-functional relationships between eye orbital imaging biomarkers and clinical visual assessments

    Science.gov (United States)

    Yao, Xiuya; Chaganti, Shikha; Nabar, Kunal P.; Nelson, Katrina; Plassard, Andrew; Harrigan, Rob L.; Mawn, Louise A.; Landman, Bennett A.

    2017-02-01

    Eye diseases and visual impairment affect millions of Americans and induce billions of dollars in annual economic burdens. Expounding upon existing knowledge of eye diseases could lead to improved treatment and disease prevention. This research investigated the relationship between structural metrics of the eye orbit and visual function measurements in a cohort of 470 patients from a retrospective study of ophthalmology records for patients (with thyroid eye disease, orbital inflammation, optic nerve edema, glaucoma, intrinsic optic nerve disease), clinical imaging, and visual function assessments. Orbital magnetic resonance imaging (MRI) and computed tomography (CT) images were retrieved and labeled in 3D using multi-atlas label fusion. Based on the 3D structures, both traditional radiology measures (e.g., Barrett index, volumetric crowding index, optic nerve length) and novel volumetric metrics were computed. Using stepwise regression, the associations between structural metrics and visual field scores (visual acuity, functional acuity, visual field, functional field, and functional vision) were assessed. Across all models, the explained variance was reasonable (R2 0.1-0.2) but highly significant (p < 0.001). Instead of analyzing a specific pathology, this study aimed to analyze data across a variety of pathologies. This approach yielded a general model for the connection between orbital structural imaging biomarkers and visual function.

  4. CSTutor: A Sketch-Based Tool for Visualizing Data Structures

    Science.gov (United States)

    Buchanan, Sarah; Laviola, Joseph J., Jr.

    2014-01-01

    We present CSTutor, a sketch-based interface designed to help students understand data structures, specifically Linked Lists, Binary Search Trees, AVL Trees, and Heaps. CSTutor creates an environment that seamlessly combines a user's sketched diagram and code. In each of these data structure modes, the user can naturally sketch a data structure on…

  5. Basic flow structure in saccular aneurysms: a flow visualization study.

    Science.gov (United States)

    Steiger, H J; Poll, A; Liepsch, D; Reulen, H J

    1987-01-01

    Basic flow patterns were investigated in a set of glass aneurysm models by means of flow visualization methods. Dye injection and streaming double refraction were used to visualize flow. The circulation inside lateral aneurysms arising at a 90 degree angle from a straight parent conduit could not be visualized by the dye-injection technique but could be demonstrated by streaming double refraction. The inflow was seen to arise from the downstream lip of the orifice and to project to the dome of the aneurysm. Backflow to the parent conduit took place along the walls of the aneurysm. In aneurysms located at bifurcations, flow characteristics depended on the geometry of the bifurcation and the flow ratio between the branches. Relatively little intra-aneurysmal flow was demonstrated in side branch-related aneurysms arising distal to an asymmetric 90 degrees bifurcation of the type encountered at the junction of the internal carotid and posterior communicating arteries. Stagnation of flow at the neck and little intra-aneurysmal circulation were found with terminal aneurysms of the basilar bifurcation type if the outflow through the branches was symmetric. With asymmetric outflow, however, or if the axis of the aneurysm did not coincide with that of the afferent vessel, an active rotation developed in these aneurysms. The size of the aneurysm had no influence on the basic pattern of intra-aneurysmal circulation. The use of pulsatile perfusion did not significantly alter the basic flow patterns observed with steady flow. Locally disturbed laminar flow was observed in certain models at physiological Reynold's numbers, but there were no signs of fully developed turbulence.

  6. Modelling and visualizing fine-scale linkage disequilibrium structure

    DEFF Research Database (Denmark)

    Edwards, David

    2013-01-01

    Background Detailed study of genetic variation at the population level in humans and other species is now possible due to the availability of large sets of single nucleotide polymorphism data. Alleles at two or more loci are said to be in linkage disequilibrium (LD) when they are correlated...... the methods they are applied to data obtained by genotyping 8341 pigs. It is found that roughly 20% of the porcine genome exhibits complex LD patterns, forming islands of relatively high genetic diversity. Conclusions The proposed algorithm is efficient and makes it feasible to estimate and visualize...

  7. Uncluttered Single-Image Visualization of Vascular Structures Using GPU and Integer Programming.

    Science.gov (United States)

    Won, Joong-Ho; Jeon, Yongkweon; Rosenberg, Jarrett K; Yoon, Sungroh; Rubin, Geoffrey D; Napel, Sandy

    2013-01-01

    Direct projection of 3D branching structures, such as networks of cables, blood vessels, or neurons onto a 2D image creates the illusion of intersecting structural parts and creates challenges for understanding and communication. We present a method for visualizing such structures, and demonstrate its utility in visualizing the abdominal aorta and its branches, whose tomographic images might be obtained by computed tomography or magnetic resonance angiography, in a single 2D stylistic image, without overlaps among branches. The visualization method, termed uncluttered single-image visualization (USIV), involves optimization of geometry. This paper proposes a novel optimization technique that utilizes an interesting connection of the optimization problem regarding USIV to the protein structure prediction problem. Adopting the integer linear programming-based formulation for the protein structure prediction problem, we tested the proposed technique using 30 visualizations produced from five patient scans with representative anatomical variants in the abdominal aortic vessel tree. The novel technique can exploit commodity-level parallelism, enabling use of general-purpose graphics processing unit (GPGPU) technology that yields a significant speedup. Comparison of the results with the other optimization technique previously reported elsewhere suggests that, in most aspects, the quality of the visualization is comparable to that of the previous one, with a significant gain in the computation time of the algorithm.

  8. Direct visualization of protease action on collagen triple helical structure.

    Directory of Open Access Journals (Sweden)

    Gabriel Rosenblum

    Full Text Available Enzymatic processing of extracellular matrix (ECM macromolecules by matrix metalloproteases (MMPs is crucial in mediating physiological and pathological cell processes. However, the molecular mechanisms leading to effective physiological enzyme-ECM interactions remain elusive. Only scant information is available on the mode by which matrix proteases degrade ECM substrates. An example is the enzymatic degradation of triple helical collagen II fragments, generated by the collagenase MMP-8 cleavage, during the course of acute inflammatory conditions by gelatinase B/MMP-9. As is the case for many other matrix proteases, it is not clear how MMP-9 recognizes, binds and digests collagen in this important physiological process. We used single molecule imaging to directly visualize this protease during its interaction with collagen fragments. We show that the initial binding is mediated by the diffusion of the protease along the ordered helix on the collagen (3/4 fragment, with preferential binding of the collagen tail. As the reaction progressed and prior to collagen degradation, gelatin-like morphologies resulting from the denaturation of the triple helical collagen were observed. Remarkably, this activity was independent of enzyme proteolysis and was accompanied by significant conformational changes of the working protease. Here we provide the first direct visualization of highly complex mechanisms of macromolecular interactions governing the enzymatic processing of ECM substrates by physiological protease.

  9. Recovery and Visualization of 3D Structure of Chromosomes from Tomographic Reconstruction Images

    Directory of Open Access Journals (Sweden)

    Tsap Leonid V

    2006-01-01

    Full Text Available The objectives of this work include automatic recovery and visualization of a 3D chromosome structure from a sequence of 2D tomographic reconstruction images taken through the nucleus of a cell. Structure is very important for biologists as it affects chromosome functions, behavior of the cell, and its state. Analysis of chromosome structure is significant in the detection of diseases, identification of chromosomal abnormalities, study of DNA structural conformation, in-depth study of chromosomal surface morphology, observation of in vivo behavior of the chromosomes over time, and in monitoring environmental gene mutations. The methodology incorporates thresholding based on a histogram analysis with a polyline splitting algorithm, contour extraction via active contours, and detection of the 3D chromosome structure by establishing corresponding regions throughout the slices. Visualization using point cloud meshing generates a 3D surface. The 3D triangular mesh of the chromosomes provides surface detail and allows a user to interactively analyze chromosomes using visualization software.

  10. A Reliable Visual Inspection Method for Vulnerability Assessment of Hyperstatic Structures Using Fuzzy Logic Analysis

    Directory of Open Access Journals (Sweden)

    Maria Valeria Piras

    2015-01-01

    Full Text Available Fuzzy logic applied to the visual inspection of existing buildings has been proposed in relation to simple structures. Isostatic structures are characterized by a unique and known collapse mechanism, which does not vary with geometry or load change. In this paper we apply fuzzy logic to visual inspection for complex structures such as hyperstatic ones in which the collapse mechanism depends not only on the geometry but also on the size and disposition of loads. The goal of this paper is to give relevant weight, in the fuzzy analysis, not only to the single expression of degradation, due to its localization within the element, but also to the structural element itself by assigning a different resistance to the various elements. The underlying aim of the proposed method is to manage, evaluate, and process all the information coming from visual inspections in order to realize a management information system for the evaluation of the safety level of even complex structures.

  11. The grammar of visual narrative: Neural evidence for constituent structure in sequential image comprehension.

    Science.gov (United States)

    Cohn, Neil; Jackendoff, Ray; Holcomb, Phillip J; Kuperberg, Gina R

    2014-11-01

    Constituent structure has long been established as a central feature of human language. Analogous to how syntax organizes words in sentences, a narrative grammar organizes sequential images into hierarchic constituents. Here we show that the brain draws upon this constituent structure to comprehend wordless visual narratives. We recorded neural responses as participants viewed sequences of visual images (comics strips) in which blank images either disrupted individual narrative constituents or fell at natural constituent boundaries. A disruption of either the first or the second narrative constituent produced a left-lateralized anterior negativity effect between 500 and 700ms. Disruption of the second constituent also elicited a posteriorly-distributed positivity (P600) effect. These neural responses are similar to those associated with structural violations in language and music. These findings provide evidence that comprehenders use a narrative structure to comprehend visual sequences and that the brain engages similar neurocognitive mechanisms to build structure across multiple domains.

  12. High strength steels, stiffness of vehicle front-end structure, and risk of injury to rear seat occupants.

    Science.gov (United States)

    Sahraei, Elham; Digges, Kennerly; Marzougui, Dhafer; Roddis, Kim

    2014-05-01

    Previous research has shown that rear seat occupant protection has decreased over model years, and front-end stiffness is a possible factor causing this trend. In this research, the effects of a change in stiffness on protection of rear seat occupants in frontal crashes were investigated. The stiffness was adjusted by using higher strength steels (DP and TRIP), or thicker metal sheets. Finite element simulations were performed, using an LS Dyna vehicle model coupled with a MADYMO dummy. Simulation results showed that an increase in stiffness, to the extent it happened in recent model years, can increase the risk of AIS3+ head injuries from 4.8% in the original model (with a stiffness of 1,000 N/mm) to 24.2% in a modified model (with a stiffness of 2,356 N/mm). The simulations also showed an increased risk of chest injury from 9.1% in the original model to 11.8% in the modified model. Distribution of injuries from real world accident data confirms the findings of the simulations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Factor structure of the Benton Visual retention tests: dimensionalization of the Benton Visual retention test, Benton Visual retention test - multiple choice, and the Visual Form Discrimination Test.

    Science.gov (United States)

    Lockwood, Courtney A; Mansoor, Yael; Homer-Smith, Elizabeth; Moses, James A

    2011-01-01

    Six sequential experiments were conducted on archival data of 610 U.S. Veterans seen at the Palo Alto Veteran's Affairs Hospital, to understand the dimensionalization of the Benton Visual retention test in both the recall (BVRT) and multiple-choice (BVRT-MC) format as well as the Visual Form Discrimination Test (VFDT). These tests were dimensionalized by the Wechsler Adult Intelligence Scale-Revised (WAIS-R) revealing a four-component model that explains 81.04% of the shared variance: the moderately difficult items (BVRT-MC and VFDT items 13-16) loaded with the WAIS-R Perceptual Organization, the easiest items (VFDT items 1-12, BVRT-MC items 1-12, and BVRT items 1-4) loaded separately with both WAIS-R Verbal Comprehension and Freedom from Distractibility, and the most difficult items (BVRT items 3-10) loaded weakly with WAIS-R Perceptual Organization.

  14. Visualizing the Structure of Iranian Medical Science Publications

    Directory of Open Access Journals (Sweden)

    Saleh Rahimi

    2014-06-01

    Full Text Available This paper presents the results of a bibliometric analysis of the Medical Sciences (MS domains in Iran. Totally 9047 articles indexed in ISI (Thomson Reuters Database from 1989 to 2008 in December 2008 have been extracted. HistCiteTM applications are used to discover the Iranian publication status during this period. The publication count has grown at an approximate rate of 40.5% per year. We tried to introduce the most productive authors, and cited works. Moreover, distributions of output in journals identified by ISI and research output analysis of different universities were presented. The most influential cited authors and articles in this research were drawn. Finally, the process of the evolution of the medical sciences discipline, and its shift over the period of the research was traced and shown in the map. Using HistCiteTM applications, retrieved articles were analyzed and visualized.

  15. Boiling visualization on vertical fins with tunnel-pore structures

    Directory of Open Access Journals (Sweden)

    Kaniowski Robert

    2012-04-01

    Full Text Available The paper presents experimental studies of nucleate boiling heat transfer from a system of connected horizontal and vertical subsurface tunnels. The experiments were carried out for water at atmospheric pressure. The tunnel external covers were manufactured out of perforated copper foil (holes diameter 0.3 mm, sintered with the mini-fins, formed on the vertical side of the 10 mm high rectangular fins and horizontal inter-fin surface. The image acquisition speed was 493 fps (at resolution 400 × 300 pixels with Photonfocus PHOT MV-D1024-160-CL camera. Visualization investigations aimed to identify nucleation sites and flow patterns and to determine the bubble departure diameter and frequency at various superheats for vertical tunnels. At low superheat vapor bubbles are generated nearly exclusively by the vertical tunnel. At medium values of superheat, pores of the horizontal tunnel activate.

  16. Structural and functional neuroimaging in patients with Parkinson's disease and visual hallucinations: A critical review.

    Science.gov (United States)

    Lenka, Abhishek; Jhunjhunwala, Ketan Ramakant; Saini, Jitender; Pal, Pramod Kumar

    2015-07-01

    Patients with Parkinson's disease (PD) may develop various non-motor symptoms (NMS) during the course of the illness and psychosis is one of the common NMS of PD. Visual hallucinations (VH) are the most common manifestation of psychosis in PD. The exact pathogenesis of VH in patients with PD is not clearly understood. Presence of VH has been described to be associated with rapid cognitive decline and increased nursing home placements in PD patients. A large number of structural and functional neuroimaging studies have been conducted to understand the cerebral basis of VH in PD. Structural imaging studies (Voxel Based Morphometry) have reported grey matter atrophy in multiple regions of the brain such as primary visual cortex, visual association cortex, limbic regions, cholinergic structures such as pedunculopontine nucleus and substantia innominata, which conclude possible alterations of brain regions associated with functions such as visuospatial-perception, attention control and memory. Most functional neuroimaging studies (functional MRI, positron emission tomography and single photon emission computerized tomography) have reported altered activation, blood flow, or reduced metabolism in both dorsal and ventral visual pathways, which probably indicates an alteration in the normal bottom-top visual processing and the presence of an aberrant top-down visual processing. This review critically analyzes the published studies on the structural and functional neuroimaging in PD patients with VH.

  17. Orthographic units in the absence of visual processing: Evidence from sublexical structure in braille.

    Science.gov (United States)

    Fischer-Baum, Simon; Englebretson, Robert

    2016-08-01

    Reading relies on the recognition of units larger than single letters and smaller than whole words. Previous research has linked sublexical structures in reading to properties of the visual system, specifically on the parallel processing of letters that the visual system enables. But whether the visual system is essential for this to happen, or whether the recognition of sublexical structures may emerge by other means, is an open question. To address this question, we investigate braille, a writing system that relies exclusively on the tactile rather than the visual modality. We provide experimental evidence demonstrating that adult readers of (English) braille are sensitive to sublexical units. Contrary to prior assumptions in the braille research literature, we find strong evidence that braille readers do indeed access sublexical structure, namely the processing of multi-cell contractions as single orthographic units and the recognition of morphemes within morphologically-complex words. Therefore, we conclude that the recognition of sublexical structure is not exclusively tied to the visual system. However, our findings also suggest that there are aspects of morphological processing on which braille and print readers differ, and that these differences may, crucially, be related to reading using the tactile rather than the visual sensory modality.

  18. Interactive 3D visualization of structural changes in the brain of a person with corticobasal syndrome

    Directory of Open Access Journals (Sweden)

    Claudia eHänel

    2014-05-01

    Full Text Available The visualization of the progression of brain tissue loss, which occurs in neurodegenerative diseases like corticobasal syndrome (CBS, is an important prerequisite to understand the course and the causes of this neurodegenerative disorder. Common workflows for visual analysis are often based on single 2D sections since in 3D visualizations more internally situated structures may be occluded by structures near the surface. The reduction of dimensions from 3D to 2D allows for an holistic view onto internal and external structures, but results in a loss of spatial information. Here, we present an application with two 3D visualization designs to resolve these challenges. First, in addition to the volume changes, the semi-transparent anatomy is displayed with an anatomical section and cortical areas for spatial orientation. Second, the principle of importance-driven volume rendering is adapted to give an unrestricted line-of-sight to relevant structures by means of a frustum-like cutout. To strengthen the benefits of the 3D visualization, we decided to provide the application next to standard desktop environments in immersive virtual environments with stereoscopic viewing as well. This improves the depth perception in general and in particular for the second design. Thus, the application presented in this work allows for aneasily comprehensible visual analysis of the extent of brain degeneration and the corresponding affected regions.

  19. The Relation of Visual Signs In The Narrative Structure of MTV Exit Human Trafficking Campaign Video

    Directory of Open Access Journals (Sweden)

    Winny Gunarti

    2013-08-01

    Full Text Available Human trafficking is a violation of the human rights. One of the campaign to fight against this crime takes the form of a digital campaign that aired on television and internet.   This study discusses the narrative structure of human trafficking campaign video from non-profit organization MTV Exit in 2012. This video campaign combines art collage and graphic art in its narrative structure. Nonverbal visual elements displayed in the form of a digital photo collage with animated illustrations setting. We consider this video campaign quite interesting as it is visually inform the public about the importance of safe migration through the visual signs in the narrative structure. This study analyzes qualitatively the relation of nonverbal visual signs in the narrative collage and illustration. Denotative and connotative analysis with structural semiotics approach is needed to understand the meaning of visual signs in the context of humans as cultural beings in their communities. This study is expected to be a model example of visual communication campaigns that can foster public awareness of the issue of human trafficking, especially for young women and children as young generation.

  20. Correlation between optic nerve head structural parameters and glaucomatous visual field indices.

    Science.gov (United States)

    Mizumoto, Kyoichi; Gosho, Masahiko; Zako, Masahiro

    2014-01-01

    We examined associations between optic nerve head structural parameters and glaucomatous visual field indices. The study population included patients with glaucomatous optic neuropathy who were evaluated at Aichi Medical University, Nagakute, Aichi, Japan, from October 2010 to January 2011. A total of 57 eyes from 33 patients were assessed. We measured visual field using a Humphrey field analyzer, peripapillary retinal nerve fiber layer thickness (RNFL-T), and Bruch's membrane opening-minimum rim width (BMO-MRW) using spectral domain optical coherence tomography, and rim area with referring three-dimensional photography. Spearman's rank correlation coefficients were calculated between the threshold of visual sensitivity or total deviation of visual field and the following five optic nerve head structural parameters: RNFL-T length, BMO-MRW length, rim area, and calculated RNFL-T and BMO-MRW volumes (each length multiplied by rim area). The Akaike information criterion was calculated to determine which structural parameter was the best predictor of each visual field index. Threshold of visual sensitivity had correlation coefficients of 0.23 with global sector of RNFL-T, 0.32 with BMO-MRW, 0.14 with rim area, 0.21 with RNFL-T volume, and 0.26 with BMO-MRW volume. The correlation coefficients for each parameter with total deviation of visual field were 0.22, 0.33, 0.28, 0.36, and 0.37, respectively. The Akaike information criterion of BMO-MRW showed the smallest values in analyses of both threshold of visual sensitivity and total deviation. The present results show that RNFL-T volume and BMO-MRW volume were more strongly correlated with total deviation than BMO-MRW, but BMO-MRW appeared to be the best predictor of the two glaucomatous visual field indices.

  1. Multi secret image color visual cryptography schemes for general access structures

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the proposed visual cryptography schemes for general access structures, the single secret image black-and-white visual cryptography schemes with meaningful shares have been constructed, in which the shares are innocent looking images. The meaningful shares have not been realized in single secret image color schemes; neither have the multi secret images color schemes. In this paper, the multi secret images color visual cryptography schemes for general access structures with meaningful shares are constructed by the method of matrix concatenation, the pixel expansion is obtained, and the validity of the scheme is proven. In our scheme, the different combination of meaningful color shares can be used to recover distinct color secret images. The multi secret images black-and-white visual cryptography scheme is a special case of our color scheme.

  2. Visualization of Distributed Data Structures for High Performance Fortran-Like Languages

    Directory of Open Access Journals (Sweden)

    Rainer Koppler

    1997-01-01

    Full Text Available This article motivates the usage of graphics and visualization for efficient utilization of High Performance Fortran's (HPF's data distribution facilities. It proposes a graphical toolkit consisting of exploratory and estimation tools which allow the programmer to navigate through complex distributions and to obtain graphical ratings with respect to load distribution and communication. The toolkit has been implemented in a mapping design and visualization tool which is coupled with a compilation system for the HPF predecessor Vienna Fortran. Since this language covers a superset of HPF's facilities, the tool may also be used for visualization of HPF data structures.

  3. The Visualization of Rotation in Diagrams of Three-Dimensional Structures.

    Science.gov (United States)

    Seddon, G. M.; And Others

    1984-01-01

    Two experiments (one using models and diagrams, one using slides) were carried out to investigate how remedial instruction may be given to students who have difficulties in visualizing the diagrammatic representation of a three-dimensional structure after the structure has been rotated. (Author/BW)

  4. On in-situ visualization for strongly coupled partitioned fluid-structure interaction

    NARCIS (Netherlands)

    Fernandes, O.; Blom, D.S.; Frey, S.; Van Zuijlen, A.H.; Bijl, H.; Ertl, T.

    2015-01-01

    We present an integrated in-situ visualization approach for partitioned multi-physics simulation of fluid-structure interaction. The simulation itself is treated as a black box and only the information at the fluid-structure interface is considered, and communicated between the fluid and solid solve

  5. Visual soil structure effects of tillage and corn stover harvest in Iowa, U.S.A.

    Science.gov (United States)

    Excessive harvest of corn (Zea mays L.) stover for ethanol production has raised concerns regarding negative consequences on soil structure and physical quality. Visual soil structure assessment methods have the potential to help address these concerns through simple, straightforward on-farm evaluat...

  6. Virtual teeth: a 3D method for editing and visualizing small structures in CT scans

    DEFF Research Database (Denmark)

    Bro-Nielsen, Morten; Larsen, Per; Kreiborg, Sven

    1996-01-01

    The paper presents an interactive method for segmentation and visualization of small structures in CT scans. A combination of isosurface generation, spatial region growing and interactive graphics tools are used to extract small structures interactively. A practical example of segmentation of the...

  7. A Java applet for multiple linked visualization of protein structure and sequence.

    Science.gov (United States)

    Oldfield, Thomas J

    2004-04-01

    The amount of biological data available from experimental techniques is huge, and rapidly expanding. The ability to make sense of this vast amount of data requires that we make correlations between distinct biological disciplines using visualization techniques to highlight the critical information. This article describes the visualization techniques of dynamic data brushing, view context maintenance, fisheye sequence view, and a magic lens that have been developed to display protein structure and sequence information.

  8. Combining Dense Structure From Motion and Visual SLAM in a Behavior-Based Robot Control Architecture

    OpenAIRE

    Geert De Cubber; Sid Ahmed Berrabah; Daniela Doroftei; Yvan Baudoin; Hichem Sahli

    2010-01-01

    In this paper, we present a control architecture for an intelligent outdoor mobile robot. This enables the robot to navigate in a complex, natural outdoor environment, relying on only a single on-board camera as sensory input. This is achieved through a twofold analysis of the visual data stream: a dense structure from motion algorithm calculates a depth map of the environment and a visual simultaneous localization and mapping algorithm builds a map of the surroundings using image features. T...

  9. Hemispheric asymmetries in subcortical visual and auditory relay structures in congenital deafness.

    Science.gov (United States)

    Amaral, L; Ganho-Ávila, A; Osório, A; Soares, M J; He, D; Chen, Q; Mahon, B Z; Gonçalves, O F; Sampaio, A; Fang, F; Bi, Y; Almeida, J

    2016-09-01

    Neuroplasticity - the capacity of the brain to change as a response to internal and external pressures - has been studied from a number of different perspectives. Perhaps one of the most powerful models is the study of populations that have been congenitally deprived of a sense. It has been shown that the right Auditory Cortex (AC) of congenitally deaf humans is neuroplastically modified in order to represent visual properties of a stimulus. One unresolved question is how this visual information is routed to the AC of congenitally deaf individuals. Here, we performed volumetric analysis of subcortical auditory and visual brains regions - namely the thalamus (along with three thalamic nuclei: the pulvinar, the lateral geniculate nucleus and the medial geniculate nucleus), and the inferior and superior colliculi - in deaf and hearing participants in order to identify which structures may be responsible for relaying visual information toward the altered AC. Because there is a hemispheric asymmetry in the neuroplastic changes observed in the AC of the congenitally deaf, we reasoned that subcortical structures that also showed a similar asymmetry in their total volume could have been enlisted in the effort of relaying visual information to the neuroplastically altered right AC. We show that for deaf, but not for hearing individuals, the right thalamus, right lateral geniculate nucleus and right inferior colliculus are larger than their left counterparts. These results suggest that these subcortical structures may be responsible for rerouting visual information to the AC in congenital deafness. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  10. Structural alteration of the dorsal visual network in DLB patients with visual hallucinations: a cortical thickness MRI study.

    Science.gov (United States)

    Delli Pizzi, Stefano; Franciotti, Raffaella; Tartaro, Armando; Caulo, Massimo; Thomas, Astrid; Onofrj, Marco; Bonanni, Laura

    2014-01-01

    Visual hallucinations (VH) represent one of the core features in discriminating dementia with Lewy bodies (DLB) from Alzheimer's Disease (AD). Previous studies reported that in DLB patients functional alterations of the parieto-occipital regions were correlated with the presence of VH. The aim of our study was to assess whether morphological changes in specific cortical regions of DLB could be related to the presence and severity of VH. We performed a cortical thickness analysis on magnetic resonance imaging data in a cohort including 18 DLB patients, 15 AD patients and 14 healthy control subjects. Relatively to DLB group, correlation analysis between the cortical thickness and the Neuropsychiatric Inventory (NPI) hallucination item scores was also performed. Cortical thickness was reduced bilaterally in DLB compared to controls in the pericalcarine and lingual gyri, cuneus, precuneus, superior parietal gyrus. Cortical thinning was found bilaterally in AD compared to controls in temporal cortex including the superior and middle temporal gyrus, part of inferior temporal cortex, temporal pole and insula. Inferior parietal and supramarginal gyri were also affected bilaterally in AD as compared to controls. The comparison between DLB and AD evidenced cortical thinning in DLB group in the right posterior regions including superior parietal gyrus, precuneus, cuneus, pericalcarine and lingual gyri. Furthermore, the correlation analysis between cortical thickness and NPI hallucination item scores showed that the structural alteration in the dorsal visual regions including superior parietal gyrus and precuneus closely correlated with the occurrence and severity of VH. We suggest that structural changes in key regions of the dorsal visual network may play a crucial role in the physiopathology of VH in DLB patients.

  11. Structural alteration of the dorsal visual network in DLB patients with visual hallucinations: a cortical thickness MRI study.

    Directory of Open Access Journals (Sweden)

    Stefano Delli Pizzi

    Full Text Available Visual hallucinations (VH represent one of the core features in discriminating dementia with Lewy bodies (DLB from Alzheimer's Disease (AD. Previous studies reported that in DLB patients functional alterations of the parieto-occipital regions were correlated with the presence of VH. The aim of our study was to assess whether morphological changes in specific cortical regions of DLB could be related to the presence and severity of VH. We performed a cortical thickness analysis on magnetic resonance imaging data in a cohort including 18 DLB patients, 15 AD patients and 14 healthy control subjects. Relatively to DLB group, correlation analysis between the cortical thickness and the Neuropsychiatric Inventory (NPI hallucination item scores was also performed. Cortical thickness was reduced bilaterally in DLB compared to controls in the pericalcarine and lingual gyri, cuneus, precuneus, superior parietal gyrus. Cortical thinning was found bilaterally in AD compared to controls in temporal cortex including the superior and middle temporal gyrus, part of inferior temporal cortex, temporal pole and insula. Inferior parietal and supramarginal gyri were also affected bilaterally in AD as compared to controls. The comparison between DLB and AD evidenced cortical thinning in DLB group in the right posterior regions including superior parietal gyrus, precuneus, cuneus, pericalcarine and lingual gyri. Furthermore, the correlation analysis between cortical thickness and NPI hallucination item scores showed that the structural alteration in the dorsal visual regions including superior parietal gyrus and precuneus closely correlated with the occurrence and severity of VH. We suggest that structural changes in key regions of the dorsal visual network may play a crucial role in the physiopathology of VH in DLB patients.

  12. Visual performance and brain structures in the developing brain of pre-term infants.

    Science.gov (United States)

    Ramenghi, Luca Antonio; Ricci, Daniela; Mercuri, Eugenio; Groppo, Michela; De Carli, Agnese; Ometto, Alessandra; Fumagalli, Monica; Bassi, Laura; Pisoni, Silvia; Cioni, Giovanni; Mosca, Fabio

    2010-07-01

    The presence of abnormal visual function has been related to overt lesions in the thalami, peritrigonal white matter (such as cavitational-necrotic periventricular leucomalacia) and optic radiations, and also to the extent of occipital cortex involvement. The normal development of visual function seems to depend on the integrity of a network that includes not only optic radiations and the primary visual cortex but also other cortical and subcortical areas, such as the frontal or temporal lobes or basal ganglia, which have been found to play a topical role in the development of vision. Therefore, the complex functions and functional connectivity of the developing brain of premature infants can be studied only with highly sophisticated techniques such as diffusion tensor tractography. The combined use of visual tests and neonatal structural and functional neuroimaging, which have become available for newborn infants, provides a better understanding of the correlation between structure and function from early life. This appears to be particularly relevant considering the essential role of early visual function in cognitive development. The identification of early visual impairment is also important, as it allows for early enrolment in intervention programmes. The association of clinical and functional studies to newer imaging techniques, which are being increasingly used also in neonates, are likely to provide further information on early aspects of vision and the mechanisms underlying brain plasticity, which are still not fully understood. Early exposure to a difficult postnatal environment together with early and unexpected removal from a protective milieu are exclusive and peculiar factors of prematurity that interfere with the normal development of the visual system in pre-term babies. The problem is further compounded by the influence of different perinatal brain lesions affecting the developing brain of premature babies. Nevertheless, in the last few decades

  13. A 3D visualization system for molecular structures

    Science.gov (United States)

    Green, Terry J.

    1989-01-01

    The properties of molecules derive in part from their structures. Because of the importance of understanding molecular structures various methodologies, ranging from first principles to empirical technique, were developed for computing the structure of molecules. For large molecules such as polymer model compounds, the structural information is difficult to comprehend by examining tabulated data. Therefore, a molecular graphics display system, called MOLDS, was developed to help interpret the data. MOLDS is a menu-driven program developed to run on the LADC SNS computer systems. This program can read a data file generated by the modeling programs or data can be entered using the keyboard. MOLDS has the following capabilities: draws the 3-D representation of a molecule using stick, ball and ball, or space filled model from Cartesian coordinates, draws different perspective views of the molecule; rotates the molecule on the X, Y, Z axis or about some arbitrary line in space, zooms in on a small area of the molecule in order to obtain a better view of a specific region; and makes hard copy representation of molecules on a graphic printer. In addition, MOLDS can be easily updated and readily adapted to run on most computer systems.

  14. Exploratory Visualization of Graphs Based on Community Structure

    Science.gov (United States)

    Liu, Yujie

    2013-01-01

    Communities, also called clusters or modules, are groups of nodes which probably share common properties and/or play similar roles within a graph. They widely exist in real networks such as biological, social, and information networks. Allowing users to interactively browse and explore the community structure, which is essential for understanding…

  15. Recovery and Visualization of 3D Structure of Chromosomes from Tomographic Reconstruction Images

    Energy Technology Data Exchange (ETDEWEB)

    Babu, S; Liao, P; Shin, M C; Tsap, L V

    2004-04-28

    The objectives of this work include automatic recovery and visualization of a 3D chromosome structure from a sequence of 2D tomographic reconstruction images taken through the nucleus of a cell. Structure is very important for biologists as it affects chromosome functions, behavior of the cell and its state. Chromosome analysis is significant in the detection of deceases and in monitoring environmental gene mutations. The algorithm incorporates thresholding based on a histogram analysis with a polyline splitting algorithm, contour extraction via active contours, and detection of the 3D chromosome structure by establishing corresponding regions throughout the slices. Visualization using point cloud meshing generates a 3D surface. The 3D triangular mesh of the chromosomes provides surface detail and allows a user to interactively analyze chromosomes using visualization software.

  16. Reduced structural connectivity in ventral visual cortex in congenital prosopagnosia.

    Science.gov (United States)

    Thomas, Cibu; Avidan, Galia; Humphreys, Kate; Jung, Kwan-jin; Gao, Fuqiang; Behrmann, Marlene

    2009-01-01

    Using diffusion tensor imaging and tractography, we found that a disruption in structural connectivity in ventral occipito-temporal cortex may be the neurobiological basis for the lifelong impairment in face recognition that is experienced by individuals who suffer from congenital prosopagnosia. Our findings suggest that white-matter fibers in ventral occipito-temporal cortex support the integrated function of a distributed cortical network that subserves normal face processing.

  17. Visually Guiding and Controlling the Search While Mining Chemical Structures

    OpenAIRE

    Max Pereira; Vitor Santos Costa; Rui Camacho; Fonseca, Nuno A.

    2009-01-01

    In this paper we present the work in progress on LogCHEM, an ILP based tool for discriminative interactive mining of chemical fragments. In particular, we describe the integration with a molecule visualisation software that allows the chemist to graphically control the search for interesting patterns in chemical fragments. Furthermore, we show how structured information, such as rings, functional groups like carboxyl, amine, methyl, ester, etc are integrated and exploited in LogCHEM.

  18. Audio-visual content structuring for automatic summarization

    OpenAIRE

    Rouvier, Mickael

    2011-01-01

    These last years, with the advent of sites such as Youtube, Dailymotion or Blip TV, the number of videos available on the Internet has increased considerably. The size and their lack of structure of these collections limit access to the contents. Sum- marization is one way to produce snippets that extract the essential content and present it as concisely as possible.In this work, we focus on extraction methods for video summary, based on au- dio analysis. We treat various scientific problems ...

  19. The modulation of stimulus structure on visual field asymmetry effects: the case of Chinese character recognition.

    Science.gov (United States)

    Hsiao, Janet H; Cheng, Liao

    2013-09-01

    Recent research suggests that visual field (VF) asymmetry effects in visual recognition may be influenced by information distribution within the stimuli for the recognition task in addition to hemispheric processing differences: Stimuli with more information on the left have a right VF (RVF) advantage because the left part is closer to the centre, where the highest visual acuity is obtained. It remains unclear whether visual complexity distribution of the stimuli also has similar modulation effects. Here we used Chinese characters with contrasting structures-left-heavy, symmetric, and right-heavy, in terms of either visual complexity of components or information distribution defined by location of the phonetic component-and examined participants' naming performance. We found that left-heavy characters had the largest RVF advantage, followed by symmetric and right-heavy characters; this effect was only observed in characters that contrasted in information distribution, in which information for pronunciation was skewed to the phonetic component, but not in those that contrasted only in visual complexity distribution and had no phonetic component. This result provides strong evidence for the influence of information distribution within the stimuli on VF asymmetry effects; in contrast, visual complexity distribution within the stimuli does not have similar modulation effects.

  20. DEVELOPMENT OF RETINAL STRUCTURE AND VISUAL ACUITY IN JAPANESE FLOUNDER (PARALICHTHYS OLIVACEUS)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The retinal structure and visual acuity in Japanese flounder Paralichthys olivaceus at different stages of development were examined by light microscopy. The resolving power of the retina, the visual axis and the best visual field were estimated based on the distribution of cone cells in the retina. The visual system of the larvae appears poorly developed at hatching. The larvae with total length (TL) of less than 10 mm, have single cones only and the eyes were well pigmented. At 10-11 mm TL, most single cones fused to form double cones, with the single and double cones forming a mosaic pattern. From larvae to early juvenile the retina stretches, the cones increase in diameter and rods increase in number. Based on the highest density of the cones in the ventro-temporal region, the visual axis was orientated up-forward. The resolving power of the retina in 40-530 mm TL Japanese flounder was found to range from 25.1 to 11.5 min. The results indicated continual improvements in the visual system of the growing fish towards higher resolving power, visual acuity and sensitivity.

  1. Cerebral basis of visual hallucinations in Parkinson's disease: structural and functional MRI studies.

    Science.gov (United States)

    Ibarretxe-Bilbao, Naroa; Junque, Carme; Marti, Maria J; Tolosa, Eduardo

    2011-11-15

    The presence of visual hallucinations (VH) is a significant predictor of dementia in Parkinson's disease (PD) and it is associated with a more rapid cognitive decline. Non-demented PD patients with VH present greater neuropsychological impairment than those without VH in domains such as verbal and visual memory, language comprehension, and visuospatial and visuoperceptive functions. Frontal dysfunction has also been described in PD with VH, including deficits in verbal fluency, sustained attention, and inhibition. In PD with VH, structural and functional abnormalities within the primary visual system and visual association areas, including ventral and dorsal pathways, have been reported. Structural MRI studies have shown that non-demented PD patients with VH present grey matter reduction in parieto-occipital areas and the hippocampal head. A follow-up study performed at a mean of 30 months revealed that unlike PD patients without VH, PD patients with VH frequently develop dementia associated with progressive atrophy in limbic, paralimbic and neocortical areas. Functional MRI (fMRI) studies have revealed altered activation in occipito-temporal and frontal areas in response to simple and complex visual stimuli in PD patients with VH, suggesting a marked impairment in bottom-up visual processing, as well as an attentional deficit in the pathophysiology of VH in PD.

  2. Robust visual tracking via structured multi-task sparse learning

    KAUST Repository

    Zhang, Tianzhu

    2012-11-09

    In this paper, we formulate object tracking in a particle filter framework as a structured multi-task sparse learning problem, which we denote as Structured Multi-Task Tracking (S-MTT). Since we model particles as linear combinations of dictionary templates that are updated dynamically, learning the representation of each particle is considered a single task in Multi-Task Tracking (MTT). By employing popular sparsity-inducing lp,q mixed norms (specifically p∈2,∞ and q=1), we regularize the representation problem to enforce joint sparsity and learn the particle representations together. As compared to previous methods that handle particles independently, our results demonstrate that mining the interdependencies between particles improves tracking performance and overall computational complexity. Interestingly, we show that the popular L1 tracker (Mei and Ling, IEEE Trans Pattern Anal Mach Intel 33(11):2259-2272, 2011) is a special case of our MTT formulation (denoted as the L11 tracker) when p=q=1. Under the MTT framework, some of the tasks (particle representations) are often more closely related and more likely to share common relevant covariates than other tasks. Therefore, we extend the MTT framework to take into account pairwise structural correlations between particles (e.g. spatial smoothness of representation) and denote the novel framework as S-MTT. The problem of learning the regularized sparse representation in MTT and S-MTT can be solved efficiently using an Accelerated Proximal Gradient (APG) method that yields a sequence of closed form updates. As such, S-MTT and MTT are computationally attractive. We test our proposed approach on challenging sequences involving heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that S-MTT is much better than MTT, and both methods consistently outperform state-of-the-art trackers. © 2012 Springer Science+Business Media New York.

  3. Visual analysis of transcriptome data in the context of anatomical structures and biological networks

    Directory of Open Access Journals (Sweden)

    Astrid eJunker

    2012-11-01

    Full Text Available The complexity and temporal as well as spatial resolution of transcriptome datasets is constantly increasing due to extensive technological developments. Here we present methods for advanced visualization and intuitive exploration of transcriptomics data as necessary prerequisites in order to facilitate the gain of biological knowledge. Color-coding of structural images based on the expression level enables a fast visual data analysis in the background of the examined biological system. The network-based exploration of these visualizations allows for comparative analysis of genes with specific transcript patterns and supports the extraction of functional relationships even from large datasets. In order to illustrate the presented methods, the tool HIVE was applied for visualization and exploration of database-retrieved expression data for master regulators of Arabidopsis thaliana flower and seed development in the context of corresponding tissue-specific regulatory networks.

  4. Bright-field Nanoscopy: Visualizing Nano-structures with Localized Optical Contrast Using a Conventional Microscope

    CERN Document Server

    Suran, Swathi; Raghavan, Srinivasan; Varma, Manoj M

    2015-01-01

    Most methods for optical visualization beyond the diffraction limit rely on fluorescence emission by molecular tags. Here, we report a method for visualization of nanostructures down to a few nanometers using a conventional bright-field microscope without requiring additional molecular tags such as fluorophores. The technique, Bright-field Nanoscopy, is based on the strong thickness dependent color of ultra-thin germanium on an optically thick gold film. We demonstrate the visualization of grain boundaries in chemical vapour deposited single layer graphene and the detection of single 40 nm Ag nanoparticles. We estimate a size detection limit of about 2 nm using this technique. In addition to visualizing nano-structures, this technique can be used to probe fluid phenomena at the nanoscale, such as transport through 2D membranes. We estimated the water transport rate through a 1 nm thick polymer film using this technique, as an illustration. Further, the technique can also be extended to study the transport of ...

  5. Gaussian weighting of ocular wave-front measurements.

    Science.gov (United States)

    Schwiegerling, Jim

    2004-11-01

    The measurement of ocular wave-front error gives insight into the optical performance of the eye and possibly a means for assessing visual performance. The visual system responds not only to the quality of the optical image formed on the retina but also to the processing that occurs in the retina and the brain. To develop a metric of visual performance based on wave-front error measurements, these latter processes must somehow be incorporated. In representing the wave-front error in terms of Zernike polynomials, it appears that terms with lower angular frequency have a greater deleterious effect on visual performance than higher-angular-frequency terms. A technique for weighting the pupil function of the eye with a Gaussian filter is demonstrated. It is further demonstrated that the variance of the Gaussian-weighted wave-front error is well correlated with visual performance.

  6. Structural visualization of the p53/RNA polymerase II assembly.

    Science.gov (United States)

    Singh, Sameer K; Qiao, Zhen; Song, Lihua; Jani, Vijay; Rice, William; Eng, Edward; Coleman, Robert A; Liu, Wei-Li

    2016-11-15

    The master tumor suppressor p53 activates transcription in response to various cellular stresses in part by facilitating recruitment of the transcription machinery to DNA. Recent studies have documented a direct yet poorly characterized interaction between p53 and RNA polymerase II (Pol II). Therefore, we dissected the human p53/Pol II interaction via single-particle cryo-electron microscopy, structural docking, and biochemical analyses. This study reveals that p53 binds Pol II via the Rpb1 and Rpb2 subunits, bridging the DNA-binding cleft of Pol II proximal to the upstream DNA entry site. In addition, the key DNA-binding surface of p53, frequently disrupted in various cancers, remains exposed within the assembly. Furthermore, the p53/Pol II cocomplex displays a closed conformation as defined by the position of the Pol II clamp domain. Notably, the interaction of p53 and Pol II leads to increased Pol II elongation activity. These findings indicate that p53 may structurally regulate DNA-binding functions of Pol II via the clamp domain, thereby providing insights into p53-regulated Pol II transcription.

  7. MindSeer: a portable and extensible tool for visualization of structural and functional neuroimaging data

    Directory of Open Access Journals (Sweden)

    Brinkley James F

    2007-10-01

    Full Text Available Abstract Background Three-dimensional (3-D visualization of multimodality neuroimaging data provides a powerful technique for viewing the relationship between structure and function. A number of applications are available that include some aspect of 3-D visualization, including both free and commercial products. These applications range from highly specific programs for a single modality, to general purpose toolkits that include many image processing functions in addition to visualization. However, few if any of these combine both stand-alone and remote multi-modality visualization in an open source, portable and extensible tool that is easy to install and use, yet can be included as a component of a larger information system. Results We have developed a new open source multimodality 3-D visualization application, called MindSeer, that has these features: integrated and interactive 3-D volume and surface visualization, Java and Java3D for true cross-platform portability, one-click installation and startup, integrated data management to help organize large studies, extensibility through plugins, transparent remote visualization, and the ability to be integrated into larger information management systems. We describe the design and implementation of the system, as well as several case studies that demonstrate its utility. These case studies are available as tutorials or demos on the associated website: http://sig.biostr.washington.edu/projects/MindSeer. Conclusion MindSeer provides a powerful visualization tool for multimodality neuroimaging data. Its architecture and unique features also allow it to be extended into other visualization domains within biomedicine.

  8. Breaking the sound barrier in recombination fronts

    CERN Document Server

    Williams, R J R

    1995-01-01

    We exploit a generic instability in the integration of steady, sonic near-isothermal flows to find the complete transition diagram for recombination fronts (for a model system of equations). The instability requires the integration of the flow equations for speeds between the isothermal and adiabatic sound speeds to be performed with particular care. As a result of this, the previous work of Newman & Axford on the structure of recombination fronts neglected an important class of solution, that of transonic fronts; our method is readily extensible to a more complete treatment of the ionization structure. Future papers will apply these results in models of the structure of ultracompact HII regions.

  9. Visualization of risk structures for interactive planning of image guided radiofrequency ablation of liver tumors

    Science.gov (United States)

    Rieder, Christian; Schwier, Michael; Weihusen, Andreas; Zidowitz, Stephan; Peitgen, Heinz-Otto

    2009-02-01

    Image guided radiofrequency ablation (RFA) is becoming a standard procedure as a minimally invasive method for tumor treatment in the clinical routine. The visualization of pathological tissue and potential risk structures like vessels or important organs gives essential support in image guided pre-interventional RFA planning. In this work our aim is to present novel visualization techniques for interactive RFA planning to support the physician with spatial information of pathological structures as well as the finding of trajectories without harming vitally important tissue. Furthermore, we illustrate three-dimensional applicator models of different manufactures combined with corresponding ablation areas in homogenous tissue, as specified by the manufacturers, to enhance the estimated amount of cell destruction caused by ablation. The visualization techniques are embedded in a workflow oriented application, designed for the use in the clinical routine. To allow a high-quality volume rendering we integrated a visualization method using the fuzzy c-means algorithm. This method automatically defines a transfer function for volume visualization of vessels without the need of a segmentation mask. However, insufficient visualization results of the displayed vessels caused by low data quality can be improved using local vessel segmentation in the vicinity of the lesion. We also provide an interactive segmentation technique of liver tumors for the volumetric measurement and for the visualization of pathological tissue combined with anatomical structures. In order to support coagulation estimation with respect to the heat-sink effect of the cooling blood flow which decreases thermal ablation, a numerical simulation of the heat distribution is provided.

  10. Hybrid Visual Servoing Control for Robotic Arc Welding Based on Structured Light Vision

    Institute of Scientific and Technical Information of China (English)

    XUDe; WANGLin-Kun; TUZhi-Guo; TANMin

    2005-01-01

    A novel hybrid visual servoing control method based on structured light vision is proposed for robotic arc welding with a general six degrees of freedom robot. It consists of a position control inner-loop in Cartesian space and two outer-loops. One is position-based visual control inCartesian space for moving in the direction of weld seam, i.e., weld seam tracking, another is imagebased visual control in image space for adjustment to eliminate the errors in the process of tracking.A new Jacobian matrix from image space of the feature point on structured light stripe to Cartesian space is provided for differential movement of the end-effector. The control system model is simplified and its stability is discussed. An experiment of arc welding protected by gas CO2 for verifying is well conducted.

  11. Information regarding structure and lightness based on phenomenal transparency influences the efficiency of visual search.

    Science.gov (United States)

    Mitsudo, Hiroyuki

    2003-01-01

    Phenomenal transparency reflects a process which makes it possible to recover the structure and lightness of overlapping objects from a fragmented image. This process was investigated by the visual-search paradigm. In three experiments, observers searched for a target that consisted of gray patches among a variable number of distractors and the search efficiency was assessed. Experiments 1 and 2 showed that the search efficiency was greatly improved when the target was distinctive with regard to structure, based on transparency. Experiment 3 showed that the search efficiency was impaired when a target was not distinctive with regard to lightness (ie perceived reflectance), based on transparency. These results suggest that the shape and reflectance of overlapping objects when accompanied by transparency can be calculated in parallel across the visual field, and can be used as a guide for visual attention.

  12. Mastering algebra retrains the visual system to perceive hierarchical structure in equations.

    Science.gov (United States)

    Marghetis, Tyler; Landy, David; Goldstone, Robert L

    2016-01-01

    Formal mathematics is a paragon of abstractness. It thus seems natural to assume that the mathematical expert should rely more on symbolic or conceptual processes, and less on perception and action. We argue instead that mathematical proficiency relies on perceptual systems that have been retrained to implement mathematical skills. Specifically, we investigated whether the visual system-in particular, object-based attention-is retrained so that parsing algebraic expressions and evaluating algebraic validity are accomplished by visual processing. Object-based attention occurs when the visual system organizes the world into discrete objects, which then guide the deployment of attention. One classic signature of object-based attention is better perceptual discrimination within, rather than between, visual objects. The current study reports that object-based attention occurs not only for simple shapes but also for symbolic mathematical elements within algebraic expressions-but only among individuals who have mastered the hierarchical syntax of algebra. Moreover, among these individuals, increased object-based attention within algebraic expressions is associated with a better ability to evaluate algebraic validity. These results suggest that, in mastering the rules of algebra, people retrain their visual system to represent and evaluate abstract mathematical structure. We thus argue that algebraic expertise involves the regimentation and reuse of evolutionarily ancient perceptual processes. Our findings implicate the visual system as central to learning and reasoning in mathematics, leading us to favor educational approaches to mathematics and related STEM fields that encourage students to adapt, not abandon, their use of perception.

  13. Structural and functional brain changes beyond visual system in patients with advanced glaucoma.

    Science.gov (United States)

    Frezzotti, Paolo; Giorgio, Antonio; Motolese, Ilaria; De Leucio, Alessandro; Iester, Michele; Motolese, Eduardo; Federico, Antonio; De Stefano, Nicola

    2014-01-01

    In order to test the hypothesis that in primary open angle glaucoma (POAG), an important cause of irreversible blindness, a spreading of neurodegeneration occurs through the brain, we performed multimodal MRI and subsequent whole-brain explorative voxelwise analyses in 13 advanced POAG patients and 12 age-matched normal controls (NC). Altered integrity (decreased fractional anisotropy or increased diffusivities) of white matter (WM) tracts was found not only along the visual pathway of POAG but also in nonvisual WM tracts (superior longitudinal fascicle, anterior thalamic radiation, corticospinal tract, middle cerebellar peduncle). POAG patients also showed brain atrophy in both visual cortex and other distant grey matter (GM) regions (frontoparietal cortex, hippocampi and cerebellar cortex), decreased functional connectivity (FC) in visual, working memory and dorsal attention networks and increased FC in visual and executive networks. In POAG, abnormalities in structure and FC within and outside visual system correlated with visual field parameters in the poorer performing eyes, thus emphasizing their clinical relevance. Altogether, this represents evidence that a vision disorder such as POAG can be considered a widespread neurodegenerative condition.

  14. Structural and effective connectivity reveals potential network-based influences on category-sensitive visual areas

    Directory of Open Access Journals (Sweden)

    Nicholas eFurl

    2015-05-01

    Full Text Available Visual category perception is thought to depend on brain areas that respond specifically when certain categories are viewed. These category-sensitive areas are often assumed to be modules (with some degree of processing autonomy and to act predominantly on feedforward visual input. This modular view can be complemented by a view that treats brain areas as elements within more complex networks and as influenced by network properties. This network-oriented viewpoint is emerging from studies using either diffusion tensor imaging to map structural connections or effective connectivity analyses to measure how their functional responses influence each other. This literature motivates several hypotheses that predict category-sensitive activity based on network properties. Large, long-range fiber bundles such as inferior fronto-occipital, arcuate and inferior longitudinal fasciculi are associated with behavioural recognition and could play crucial roles in conveying backward influences on visual cortex from anterior temporal and frontal areas. Such backward influences could support top-down functions such as visual search and emotion-based visual modulation. Within visual cortex itself, areas sensitive to different categories appear well-connected (e.g., face areas connect to object- and motion sensitive areas and their responses can be predicted by backward modulation. Evidence supporting these propositions remains incomplete and underscores the need for better integration of DTI and functional imaging.

  15. Population genetic structure of the blue-fronted Amazon (Amazona aestiva, Psittacidae: Aves) based on nuclear microsatellite loci: implications for conservation.

    Science.gov (United States)

    Leite, K C E; Seixas, G H F; Berkunsky, I; Collevatti, R G; Caparroz, R

    2008-09-09

    The blue-fronted Amazon (Amazona aestiva) is a widely distributed Neotropical parrot and one of the most captured parrots in nature to supply the illegal trade of wild animals. The objectives of the present study were to analyze the genetic structure of A. aestiva to identify management units and support conservation planning and to verified if A. aestiva populations have undergone a recent bottleneck due to habitat loss and capture for the pet trade. The genetic structure was accessed by analyzing six microsatellite loci in 74 individuals of A. aestiva, including samples from the two subspecies (A. a. aestiva and A. a. xanthopteryx), from five populations: four in Brazil and one in Argentina. A significant genetic differentiation (theta = 0.007, p = 0.005) could be detected only between the most distant populations, Tocantins and Argentina, localized at the northeast and southwest limits of the sample sites, respectively. There was no evidence of inbreeding within or between populations, suggesting random mating among individuals. These results suggest a clinal distribution of genetic variability, as observed for variation in plumage color of the two A. aestiva subspecies. Bottleneck analysis did not show a recent reduction in population size. Thus, for the management and conservation of the species, the populations from Argentina and Tocantins should be considered as different management units, and the other populations from the center of the geographical distribution as another management unit.

  16. Structural Analysis and Visualization of C++ Code Evolution using Syntax Trees

    NARCIS (Netherlands)

    Chevalier, Fanny; Auber, David; Telea, Alexandru

    2007-01-01

    We present a method to detect and visualize evolution patterns in C++ source code. Our method consists of three steps. First, we extract an annotated syntax tree (AST) from each version of a given C++ source code. Next, we hash the extracted syntax nodes based on a metric combining structure and typ

  17. Combined Visualization of Structural and Metric Information for Software Evolution Analysis

    NARCIS (Netherlands)

    Gonzalez, Antonio; Theron, Roberto; Telea, Alexandru; Garcia, Francisco J.

    2009-01-01

    This paper discusses a proposal for the visualization of software evolution, with a focus on combining insight on changes that affect software metrics at project and class level, the project structure, the class hierarchy and the viewing of source code correlated to indirect class coupling. The prop

  18. Constructivist-Visual Mind Map Teaching Approach and the Quality of Students' Cognitive Structures

    Science.gov (United States)

    Dhindsa, Harkirat S.; Makarimi-Kasim; Anderson, O. Roger

    2011-01-01

    This study compared the effects of a constructivist-visual mind map teaching approach (CMA) and of a traditional teaching approach (TTA) on (a) the quality and richness of students' knowledge structures and (b) TTA and CMA students' perceptions of the extent that a constructivist learning environment (CLE) was created in their classes. The sample…

  19. Integrating Algorithm Visualization Video into a First-Year Algorithm and Data Structure Course

    Science.gov (United States)

    Crescenzi, Pilu; Malizia, Alessio; Verri, M. Cecilia; Diaz, Paloma; Aedo, Ignacio

    2012-01-01

    In this paper we describe the results that we have obtained while integrating algorithm visualization (AV) movies (strongly tightened with the other teaching material), within a first-year undergraduate course on algorithms and data structures. Our experimental results seem to support the hypothesis that making these movies available significantly…

  20. Design and Implementation of Visualized Workflow Modeling System Based on B/S Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; LI wei-li

    2007-01-01

    According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications of WfMC and the workflow process definition meta-modei. The design for system structure is presented in detail, and the key technologies for system implementation are also introduced. Additionally, an example is illustrated to demonstrate the validity of system.

  1. The Relation of Visual Signs In The Narrative Structure of MTV Exit Human Trafficking Campaign Video

    OpenAIRE

    Winny Gunarti; Dendi Pratama; Rina Wahyu Winarni

    2013-01-01

    Human trafficking is a violation of the human rights. One of the campaign to fight against this crime takes the form of a digital campaign that aired on television and internet.   This study discusses the narrative structure of human trafficking campaign video from non-profit organization MTV Exit in 2012. This video campaign combines art collage and graphic art in its narrative structure. Nonverbal visual elements displayed in the form of a digital photo collage with animated illustrations s...

  2. Deformation in the Bolivian Subandes: a reconstruction of geologic structures along two transects across the Andean Front in Southern Bolivia

    Science.gov (United States)

    Hadeen, Xennephone; Zeilinger, Gerold

    2016-04-01

    The Southern Bolivian Subandes is a highly tectonically active region in the Andes since deformation began approx. 10 Ma ago. The study area is located in the Southern Bolivian Subandes southwest of Santa Cruz. Observations were taken along two transects with each being around 100 km long. They stretch from the Subandes-Interandean boundary into the Chaco Plain. The northern transect extends from Abapó in the Chaco Plain and it continues west near Vallegrande and ends just west of Pucara near La Higuera. The southern transect initiates near Charagua in the Chaco Plain. Then it continues west through Villa Vaca Guzmán and ends around 25 km west of Monteagudo. Structural and stratigraphic data were collected along the two transects. The locations of major geologic structures such as thrust faults, anticlines and synclines were mapped. The map along with the data from the two cross sections was then used to generate a 3D model of the Subandean fold and thrust belt between Abapó and Monteagudo. The cross sections were than restored to quantify the amount of shortening that had occurred over the past 10 million years. The southern transect has undergone 65 km of shortening while 50 to 80 km of shortening have transpired along the less constrain northern transect. The estimated rate of deformation averages at 8 mm/yr. The timing of deformation may differ between the two transects. Deformation may have initiated earlier or undergone at a faster rate in the northern transect than in the southern transect. It is also possible that the decollement is shallower in the western portion of the northern transect. We observe that the east propagating anticlines verge to the west. This may be due to the anticlines being cut by exposed or blind thrust faults and then rotated counterclockwise. They rotate while piggybacking on younger thrust faults that developed and propagate to the east of the anticlines. We postulate deformation continues to propagate eastward into the Chaco

  3. ViVar: a comprehensive platform for the analysis and visualization of structural genomic variation.

    Science.gov (United States)

    Sante, Tom; Vergult, Sarah; Volders, Pieter-Jan; Kloosterman, Wigard P; Trooskens, Geert; De Preter, Katleen; Dheedene, Annelies; Speleman, Frank; De Meyer, Tim; Menten, Björn

    2014-01-01

    Structural genomic variations play an important role in human disease and phenotypic diversity. With the rise of high-throughput sequencing tools, mate-pair/paired-end/single-read sequencing has become an important technique for the detection and exploration of structural variation. Several analysis tools exist to handle different parts and aspects of such sequencing based structural variation analyses pipelines. A comprehensive analysis platform to handle all steps, from processing the sequencing data, to the discovery and visualization of structural variants, is missing. The ViVar platform is built to handle the discovery of structural variants, from Depth Of Coverage analysis, aberrant read pair clustering to split read analysis. ViVar provides you with powerful visualization options, enables easy reporting of results and better usability and data management. The platform facilitates the processing, analysis and visualization, of structural variation based on massive parallel sequencing data, enabling the rapid identification of disease loci or genes. ViVar allows you to scale your analysis with your work load over multiple (cloud) servers, has user access control to keep your data safe and is easy expandable as analysis techniques advance. URL: https://www.cmgg.be/vivar/

  4. ViVar: a comprehensive platform for the analysis and visualization of structural genomic variation.

    Directory of Open Access Journals (Sweden)

    Tom Sante

    Full Text Available Structural genomic variations play an important role in human disease and phenotypic diversity. With the rise of high-throughput sequencing tools, mate-pair/paired-end/single-read sequencing has become an important technique for the detection and exploration of structural variation. Several analysis tools exist to handle different parts and aspects of such sequencing based structural variation analyses pipelines. A comprehensive analysis platform to handle all steps, from processing the sequencing data, to the discovery and visualization of structural variants, is missing. The ViVar platform is built to handle the discovery of structural variants, from Depth Of Coverage analysis, aberrant read pair clustering to split read analysis. ViVar provides you with powerful visualization options, enables easy reporting of results and better usability and data management. The platform facilitates the processing, analysis and visualization, of structural variation based on massive parallel sequencing data, enabling the rapid identification of disease loci or genes. ViVar allows you to scale your analysis with your work load over multiple (cloud servers, has user access control to keep your data safe and is easy expandable as analysis techniques advance. URL: https://www.cmgg.be/vivar/

  5. Case studies on mesoscale structures of heavy rainfall system in the Yangtze River generated by Meiyu front

    Institute of Scientific and Technical Information of China (English)

    LIU; Liping; RUAN; Zheng

    2005-01-01

    A heavy rainfall system was observed over the Yangtze River during Meiyu season by using dual-Doppler radar systems in the field experiment conducted by the project of National Fundamental Research Planning "Research on formation mechanism and the prediction theory of hazardous weather over China". The three-dimensional mesoscale kinematic structure and process of a heavy rain on 22 and 23 July, 2002 are investigated by using the radial velocity and dual-Doppler radar technique. The results show that a southwest-northeast oriented rain band with the length of about 1000 km involves numbers of meso-β or meso-γ-scale convective cells with the size of 20―50 km. The heavy rain band in the middle reaches of the Yangtze River exists in a low-level wind shear. The interaction between southwest low-level jet on the southern side of wind shear and east wind on the northern side formed the updraft. The wind disturbance, wind shear and convergence generate the convective action. The new cell developed in right rear flank of rain band and moved to the southwest wind area, where the vapor is abundant. This kind of echo can last a long time and developed well. The strong convective echoes are often accompanied by the meso-γ-scale vortex and convergence.

  6. A guide to the visual analysis and communication of biomolecular structural data.

    Science.gov (United States)

    Johnson, Graham T; Hertig, Samuel

    2014-10-01

    Biologists regularly face an increasingly difficult task - to effectively communicate bigger and more complex structural data using an ever-expanding suite of visualization tools. Whether presenting results to peers or educating an outreach audience, a scientist can achieve maximal impact with minimal production time by systematically identifying an audience's needs, planning solutions from a variety of visual communication techniques and then applying the most appropriate software tools. A guide to available resources that range from software tools to professional illustrators can help researchers to generate better figures and presentations tailored to any audience's needs, and enable artistically inclined scientists to create captivating outreach imagery.

  7. Developmental synergy between thalamic structure and interhemispheric connectivity in the visual system of preterm infants

    Directory of Open Access Journals (Sweden)

    Rafael Ceschin

    2015-01-01

    Full Text Available Thalamic structural co-variation with cortical regions has been demonstrated in preterm infants, but its relationship to cortical function and severity of non-cystic white matter injury (non-cystic WMI is unclear. The relationship between thalamic morphology and both cortical network synchronization and cortical structural connectivity has not been established. We tested the hypothesis that in preterm neonates, thalamic volume would correlate with primary cortical visual function and microstructural integrity of cortico-cortical visual association pathways. A total of 80 term-equivalent preterm and 44 term-born infants underwent high-resolution structural imaging coupled with visual functional magnetic resonance imaging or diffusion tensor imaging. There was a strong correlation between thalamic volume and primary visual cortical activation in preterms with non-cystic WMI (r = 0.81, p-value = 0.001. Thalamic volume also correlated strongly with interhemispheric cortico-cortical connectivity (splenium in preterm neonates with a relatively higher severity of non-cystic WMI (p-value < 0.001. In contrast, there was lower correlation between thalamic volume and intrahemispheric cortico-cortical connectivity, including the inferior longitudinal fasciculus and inferior frontal orbital fasciculus. This study shows distinct temporal overlap in the disruption of thalamo-cortical and interhemispheric cortico-cortical connectivity in preterm infants suggesting developmental synergy between thalamic morphology and the emergence of cortical networks in the last trimester.

  8. 3-D seismic imaging of lithospheric fault-block structures, core complexes, alteration fronts, and hydrothermal systems along the Mid-Atlantic Ridge, Rainbow area

    Science.gov (United States)

    Dunn, R. A.; Arai, R.; Eason, D. E.; Canales, J. P.; Sohn, R. A.

    2016-12-01

    Oceanic lithosphere formed along slow-spreading mid-ocean ridges is structurally and compositionally heterogeneous due to spatial and temporal variations in tectonic extension and magmatic accretion processes. Sorting out the different influences requires detailed imaging of the subsurface. The MARINER seismic and geophysical mapping experiment was designed to examine seafloor spreading across an area that includes a non-transform offset of the Mid-Atlantic Ridge, 36°14'N, the site of the Rainbow core complex and its associated hydrothermal vent field. Using seismic refraction data from this experiment, we constructed three-dimensional anisotropic tomographic images of the crust and upper mantle around the Rainbow area. Approaching Rainbow along the spreading ridges from either side, the seismic images reveal the onset of a clear ridge-parallel stripe-like structures, with alternating high- and low-velocities throughout the crust, correlated with changing lower crustal thickness and the locations of large normal faults. The pattern indicates that large normal faults rotate large blocks of the entire crust during tectonic stretching. Sitting within the ridge offset, the Rainbow core complex appears to be genetically related to neighboring fault blocks, and is largely an ultramafic exposure. Relatively low seismic velocities drape the core complex, having a sharp contact with higher-velocities below. The sharp contact may demarcate alteration (to serpentinite) and cracking fronts, since also draping the core complex are corresponding regions of high seismic anisotropy and high microseismicity, indicating pervasive cracking of its upper regions. The anisotropy and seismicity funnel upwards under the vent field, presumably marking the flow paths of vent fluids that cool melt lenses found to be intruded deep below the surface. The tomographic images reveal lithospheric structures in greater detail than previously possible, and when taken together with our other

  9. Enhancing the usability and performance of structured association mapping algorithms using automation, parallelization, and visualization in the GenAMap software system

    Directory of Open Access Journals (Sweden)

    Curtis Ross E

    2012-04-01

    Full Text Available Abstract Background Structured association mapping is proving to be a powerful strategy to find genetic polymorphisms associated with disease. However, these algorithms are often distributed as command line implementations that require expertise and effort to customize and put into practice. Because of the difficulty required to use these cutting-edge techniques, geneticists often revert to simpler, less powerful methods. Results To make structured association mapping more accessible to geneticists, we have developed an automatic processing system called Auto-SAM. Auto-SAM enables geneticists to run structured association mapping algorithms automatically, using parallelization. Auto-SAM includes algorithms to discover gene-networks and find population structure. Auto-SAM can also run popular association mapping algorithms, in addition to five structured association mapping algorithms. Conclusions Auto-SAM is available through GenAMap, a front-end desktop visualization tool. GenAMap and Auto-SAM are implemented in JAVA; binaries for GenAMap can be downloaded from http://sailing.cs.cmu.edu/genamap.

  10. 时间线和地形式可视化图谱:科学传播研究前沿演进趋势分析%Timeline and Landscape: A Case Study of Visualizing the Evolution of Science Communication Research Front

    Institute of Scientific and Technical Information of China (English)

    张婷

    2009-01-01

    研究前沿是在一门学科领域中研究者最热衷、最新的研究主题.运用时间线和地形式可视化图谱方法进行研究前沿的确定和描绘,由原来的二维时间线图谱扩展至三维动态地形式图谱,为研究前沿的发展趋势绘制更加清晰可视化并具有动态性的知识图谱.以一份科学传播研究领域的权威期刊(Science Communication)杂志1994~2007年的数据为例,对科学传播的研究前沿进行了可视化地梳理和描述,绘制出时间线和地形式可视化图谱,试图随着时间变化来演示科学传播领域研究前沿的动态变化过程与发展趋势,为技术预测和学科发展提供借鉴.%Research fronts are clusters of documents that tend to cite a fixed,time invariant set of base documents.In a specialty,research fronts are considered as major topics that most researchers are interested in. This paper plots the research fronts in science communication as timelines and landscapes for visualization. Timelines and landscapes,as new techniques of mapping knowledge domains, take advantage of a set of data processing and querying technologies based on Matlab and database prior to those based on text and memory. A set of data,collected from the reputable journal named Science Communication from 1994 to 2007 are used to manifest the dynamics and evolution of science communication research fronts over time. The mapping techniques are based on finding 'research fronts' consisting of groups of papers clustered using bibliographic coupling. Timelines of research fronts,two-dimension maps,show the specialty dynamics over time. Landscapes of research fronts are three-dimension plots with many peaks rising one after another over time. Landscapes show the panorama of research fronts in science communication,and comparison of various research fronts over time comes to be easier in fact. Such information will provide some references for technology forecasting and further knowledge

  11. Extra-visual functional and structural connection abnormalities in Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Rocca, Maria A; Valsasina, Paola; Pagani, Elisabetta; Bianchi-Marzoli, Stefania; Milesi, Jacopo; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

    2011-02-10

    We assessed abnormalities within the principal brain resting state networks (RSNs) in patients with Leber's hereditary optic neuropathy (LHON) to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT) MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits.

  12. Extra-visual functional and structural connection abnormalities in Leber's hereditary optic neuropathy.

    Directory of Open Access Journals (Sweden)

    Maria A Rocca

    Full Text Available We assessed abnormalities within the principal brain resting state networks (RSNs in patients with Leber's hereditary optic neuropathy (LHON to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits.

  13. A review of visual memory capacity: Beyond individual items and toward structured representations.

    Science.gov (United States)

    Brady, Timothy F; Konkle, Talia; Alvarez, George A

    2011-05-26

    Traditional memory research has focused on identifying separate memory systems and exploring different stages of memory processing. This approach has been valuable for establishing a taxonomy of memory systems and characterizing their function but has been less informative about the nature of stored memory representations. Recent research on visual memory has shifted toward a representation-based emphasis, focusing on the contents of memory and attempting to determine the format and structure of remembered information. The main thesis of this review will be that one cannot fully understand memory systems or memory processes without also determining the nature of memory representations. Nowhere is this connection more obvious than in research that attempts to measure the capacity of visual memory. We will review research on the capacity of visual working memory and visual long-term memory, highlighting recent work that emphasizes the contents of memory. This focus impacts not only how we estimate the capacity of the system--going beyond quantifying how many items can be remembered and moving toward structured representations--but how we model memory systems and memory processes.

  14. Comparative Visual Analysis of Structure-Performance Relations in Complex Bulk-Heterojunction Morphologies

    KAUST Repository

    Aboulhassan, A.

    2017-07-04

    The structure of Bulk-Heterojunction (BHJ) materials, the main component of organic photovoltaic solar cells, is very complex, and the relationship between structure and performance is still largely an open question. Overall, there is a wide spectrum of fabrication configurations resulting in different BHJ morphologies and correspondingly different performances. Current state-of-the-art methods for assessing the performance of BHJ morphologies are either based on global quantification of morphological features or simply on visual inspection of the morphology based on experimental imaging. This makes finding optimal BHJ structures very challenging. Moreover, finding the optimal fabrication parameters to get an optimal structure is still an open question. In this paper, we propose a visual analysis framework to help answer these questions through comparative visualization and parameter space exploration for local morphology features. With our approach, we enable scientists to explore multivariate correlations between local features and performance indicators of BHJ morphologies. Our framework is built on shape-based clustering of local cubical regions of the morphology that we call patches. This enables correlating the features of clusters with intuition-based performance indicators computed from geometrical and topological features of charge paths.

  15. 3D Geo-Structures Visualization Education Project (3dgeostructuresvis.ucdavis.edu)

    Science.gov (United States)

    Billen, M. I.

    2014-12-01

    Students of field-based geology must master a suite of challenging skills from recognizing rocks, to measuring orientations of features in the field, to finding oneself (and the outcrop) on a map and placing structural information on maps. Students must then synthesize this information to derive meaning from the observations and ultimately to determine the three-dimensional (3D) shape of the deformed structures and their kinematic history. Synthesizing this kind of information requires sophisticated visualizations skills in order to extrapolate observations into the subsurface or missing (eroded) material. The good news is that students can learn 3D visualization skills through practice, and virtual tools can help provide some of that practice. Here I present a suite of learning modules focused at developing students' ability to imagine (visualize) complex 3D structures and their exposure through digital topographic surfaces. Using the software 3DVisualizer, developed by KeckCAVES (keckcaves.org) we have developed visualizations of common geologic structures (e.g., syncline, dipping fold) in which the rock is represented by originally flat-lying layers of sediment, each with a different color, which have been subsequently deformed. The exercises build up in complexity, first focusing on understanding the structure in 3D (penetrative understanding), and then moving to the exposure of the structure at a topographic surface. Individual layers can be rendered as a transparent feature to explore how the layer extends above and below the topographic surface (e.g., to follow an eroded fold limb across a valley). The exercises are provided using either movies of the visualization (which can also be used for examples during lectures), or the data and software can be downloaded to allow for more self-driven exploration and learning. These virtual field models and exercises can be used as "practice runs" before going into the field, as make-up assignments, as a field

  16. Wave-front analysis of personal eye protection.

    Science.gov (United States)

    Eppig, Timo; Zoric, Katja; Speck, Alexis; Zelzer, Benedikt; Götzelmann, Jens; Nagengast, Dieter; Langenbucher, Achim

    2012-07-30

    Shack-Hartmann wave-front sensing has been successfully applied to many fields of optical testing including the human eye itself. We propose wave-front measurement for testing protective eye wear for production control and investigation of aberrations. Refractive power data is derived from the wave-front data and compared to a subjective measurement technique based on a focimeter. Additional image quality classification was performed with a multivariate model using objective parameters to resample a subjectively determined visual quality. Wave-front measurement advances optical testing of protective eye wear and may be used for objective quality control.

  17. Structural Analysis and Visualization of C++ Code Evolution using Syntax Trees

    OpenAIRE

    Chevalier, Fanny; Auber, David; Telea, Alexandru

    2007-01-01

    International audience; We present a method to detect and visualize evolution patterns in C++ source code. Our method consists of three steps. First, we extract an annotated syntax tree (AST) from each version of a given C++ source code. Next, we hash the extracted syntax nodes based on a metric combining structure and type information, and construct matches (correspondences) between similar-hash subtrees. Our technique detects code fragments which have not changed, or changed little, during ...

  18. Multi Front-End Engineering

    Science.gov (United States)

    Botterweck, Goetz

    Multi Front-End Engineering (MFE) deals with the design of multiple consistent user interfaces (UI) for one application. One of the main challenges is the conflict between commonality (all front-ends access the same application core) and variability (multiple front-ends on different platforms). This can be overcome by extending techniques from model-driven user interface engineering.We present the MANTRA approach, where the common structure of all interfaces of an application is modelled in an abstract UI model (AUI) annotated with temporal constraints on interaction tasks. Based on these constraints we adapt the AUI, e.g., to tailor presentation units and dialogue structures for a particular platform. We use model transformations to derive concrete, platform-specific UI models (CUI) and implementation code. The presented approach generates working prototypes for three platforms (GUI, web, mobile) integrated with an application core via web service protocols. In addition to static evaluation, such prototypes facilitate early functional evaluations by practical use cases.

  19. Collisionless ion dynamics in the shock front

    Science.gov (United States)

    Gedalin, Michael

    2016-07-01

    In the vicinity of the shock front the dynamics of ions is governed by the macroscopic regular electric and magnetic field of the shock. Upon crossing the shock the thermal ions form a non-gyrotropic distribution. The pressure of these non-gyrotropic ions shapes the downstream magnetic field. High-energy ions behave in the shock front as test particles under the influence on the macroscopic fields. The reflection and transmission coefficients of high-energy ions at an oblique shock front is not sensitive to the shock structure and depends only on the global magnetic field change at the shock.

  20. Functional and structural comparison of visual lateralization in birds – similar but still different

    Directory of Open Access Journals (Sweden)

    Martina eManns

    2014-03-01

    Full Text Available Vertebrate brains display physiological and anatomical left-right differences, which are related to hemispheric dominances for specific functions. Functional lateralizations likely rely on structural left-right differences in intra- and interhemispheric connectivity patterns that develop in tight gene-environment interactions. The visual systems of chickens and pigeons show that asymmetrical light stimulation during ontogeny induces a dominance of the left hemisphere for visuomotor control that is paralleled by projection asymmetries within the ascending visual pathways. But structural asymmetries vary essentially between both species concerning the affected pathway (thalamo- vs. tectofugal system, constancy of effects (transient vs. permanent, and the hemisphere receiving stronger bilateral input (right vs. left. These discrepancies suggest that at least two aspects of visual processes are influenced by asymmetric light stimulation: 1. Visuomotor dominance develops within the ontogenetically stronger stimulated hemisphere but not necessarily in the one receiving stronger bottom-up input. As a secondary consequence of asymmetrical light experience, lateralized top-down mechanisms play a critical role in the emergence of hemispheric dominance. 2. Ontogenetic light experiences may affect the dominant use of left- and right-hemispheric strategies. Evidences from social and spatial cognition tasks indicate that chickens rely more on a right-hemispheric global strategy whereas pigeons display a dominance of the left hemisphere. Thus, behavioural asymmetries are linked to a stronger bilateral input to the right hemisphere in chickens but to the left one in pigeons. The degree of bilateral visual input may determine the dominant visual processing strategy when redundant encoding is possible. This analysis supports that environmental stimulation affects the balance between hemispheric-specific processing by lateralized interactions of bottom-up and top

  1. Insights into Planar Magnetic Solar Wind Structures Using New Visualization Methods

    Science.gov (United States)

    Roberts, D. A.; Luckyanova, M.; Rezapkin, V.; Boller, R.

    2004-12-01

    We examine the structure of the solar wind using one to four spacecraft at a time, applying a kinematic projection of the data to create spatial pictures. The results are visualized using ViSBARD (Visual System for Browsing, Analysis, and Retrieval of Data) that presents the results in 3-D, allowing a variety of manipulations. Specifically, we examine the degree to which a set of ``Planar Magnetic Structures" previously examined with ISEE-3 data are actually planar. Those with very low ratios of the minimum to the intermediate variance eigenvalues do appear quite planar, but as the ratio approaches the typical cutoff of ~2.5, it becomes difficult to identify what might be the plane of variation. We use the Alfvénicity of the intervals to show that the smoothly regions around the PMSs (which often form a ``cone" of magnetic vectors, consistent with the idea of a random walk on a sphere) are much more Alfvénic than the PMS structures. We also find that frequently the PMS structures show systematic rotations that suggest a small magnetic cloud structure. The evidence thus supports the idea that a large fraction of the PMS structures are non-wavelike flux-tubes that are convected outward from the Sun. The rapid rotations of the field used to characterize the PMS regions are very frequently associated with magnetic holes, consistent with spiral magnetic fields associated with current sheets that have been seen in MHD simulations.

  2. GPU-accelerated analysis and visualization of large structures solved by molecular dynamics flexible fitting.

    Science.gov (United States)

    Stone, John E; McGreevy, Ryan; Isralewitz, Barry; Schulten, Klaus

    2014-01-01

    Hybrid structure fitting methods combine data from cryo-electron microscopy and X-ray crystallography with molecular dynamics simulations for the determination of all-atom structures of large biomolecular complexes. Evaluating the quality-of-fit obtained from hybrid fitting is computationally demanding, particularly in the context of a multiplicity of structural conformations that must be evaluated. Existing tools for quality-of-fit analysis and visualization have previously targeted small structures and are too slow to be used interactively for large biomolecular complexes of particular interest today such as viruses or for long molecular dynamics trajectories as they arise in protein folding. We present new data-parallel and GPU-accelerated algorithms for rapid interactive computation of quality-of-fit metrics linking all-atom structures and molecular dynamics trajectories to experimentally-determined density maps obtained from cryo-electron microscopy or X-ray crystallography. We evaluate the performance and accuracy of the new quality-of-fit analysis algorithms vis-à-vis existing tools, examine algorithm performance on GPU-accelerated desktop workstations and supercomputers, and describe new visualization techniques for results of hybrid structure fitting methods.

  3. Visualization of Coherent Structures in Acoustically Forced,Gas-Particle Turbulent Round Jet

    Institute of Scientific and Technical Information of China (English)

    容易; 张会强; 王希麟; 陈昌麒

    2004-01-01

    To show the effects of the particles and forced disturbances on the instantaneous large-scale vortex structures in a gas-particle round jet, coherent structures in gas-particle turbulent round jets were investigated experimentally by flow visualization. The 45-μm and 350-μm diameter glass beads were used as the particles in the experiments. An acoustic speaker was used to introduce velocity perturbations at the jet exit. The Strouhal number based on the nozzle diameter, exit velocity, and forcing frequency was varied from 0.1 to 0.9. The Reynolds number was 9400. The coherent structures were visualized in unforced and forced single-phase jet flows and unforced and forced particle-laden jet flows with different diameter glass beads. The experimental results show that the particles have significant effects on the gas phase coherent structures. The coherent structures are controlled by the large 350-μm diameter particles, while the structures are mainly dominated by the forced disturbances in the flows with 45-μm diameter particles.

  4. Spatial Visualization Tasks To Support Students’ Spatial Structuring In Learning Volume Measurement

    Directory of Open Access Journals (Sweden)

    Shintia Revina

    2011-07-01

    Full Text Available Many prior researches found that most of students in grade five tended to have difficulty in fully grasping the concept of volume measurement because they have to build their competence in spatial structuring. The unit of volume “packing” measurement must be integrated and coordinated in three-dimension. On the other hand, it is revealed the errors that students made on the volume measurement tasks with threedimensional cube arrays are related to some aspects of spatial visualization, such as the skill to "read off" two-dimensional representation of solid objects. For those reasons, this research is aimed to develop classroom activities with the use of spatial visualization tasks to support students’ spatial structuring in learning volume measurement. Consequently, design research was chosen as an appropriate means to achieve this research goal. In this research, a sequence of instructional activities is designed and developed based on the hypothesis of students’ learning processes. This research was conducted in grade 5 of SD Pupuk Sriwijaya Palembang, Indonesia.Keywords: volume measurement, spatial structuring, spatial visualization, design research. DOI: http://dx.doi.org/10.22342/jme.2.2.745.127-146

  5. Visual analysis of uncertainties in ocean forecasts for planning and operation of off-shore structures

    KAUST Repository

    Hollt, Thomas

    2013-02-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean forecasting, i.e, simulations of sea surface elevation. Our system enables the interactive planning of both the placement and operation of off-shore structures. We illustrate this using a real-world simulation of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by strong loop currents. The oil and gas industry therefore relies on accurate ocean forecasting systems for planning their operations. Nowadays, these forecasts are based on multiple spatio-temporal simulations resulting in multidimensional, multivariate and multivalued data, so-called ensemble data. Changes in sea surface elevation are a good indicator for the movement of loop current eddies, and our visualization approach enables their interactive exploration and analysis. We enable analysis of the spatial domain, for planning the placement of structures, as well as detailed exploration of the temporal evolution at any chosen position, for the prediction of critical ocean states that require the shutdown of rig operations. © 2013 IEEE.

  6. Internal consistency and factor structure of 12-item general health questionnaire in visually impaired students

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Bakhla

    2013-01-01

    Full Text Available Background: As there are no instruments to measure psychological wellness or distress in visually impaired students, we studied internal consistency and factor structure of GHQ-12 in visually impaired children. Materials and Methods: Internal consistency analysis (Cronbach′s alpha and item total correlation and exploratory factor analysis (principal component analysis were carried out to identify factor structure of 12-item general health questionnaire (GHQ-12. Results: All items of GHQ-12 were significantly associated with each other and the Cronbach′s alpha coefficient for the scale was 0.7. On analysis of principal component, three-factor solution was found that accounted for 47.92% of the total variance. The factors included, ′general well-being′, ′depression′ and ′cognitive′, with Cronbach′s alpha coefficients being 0.70, 0.59, and 0.34, respectively. Conclusion: Our study findings suggest GHQ-12 is a reliable with adequate internal consistency scale and multidimensional factor structure in visually impaired students.

  7. VERTICAL STRUCTURE OF THE LOW LEVEL ATMOSPHERE AROUND THE SOUTHEAST INDIAN OCEAN FRONTS%东南印度洋海洋锋面处低空大气的垂向分布结构

    Institute of Scientific and Technical Information of China (English)

    刘琳; 高立宝

    2012-01-01

    本文利用中国第25次南极科学考察期间获取的现场观测数据研究了东南印度洋(弗里曼特尔至中山站间)海洋锋面附近的低空大气风场以及温度场垂向分布特征.结果表明:弗里曼特尔港至中山站之间的亚南极锋锋面暖水侧与冷水侧风速垂向分布结构不同,锋面暖水侧风速垂向梯度小,风速梯度最大值出现在500m高度附近,而锋面冷水侧低空风速梯度最人值出现在150m高度附近,揭示了中纬度海气相互作用机制在东南印度洋海洋锋面附近起重要作用.同时,本文还发现了亚南极锋锋面上空存在一支强的低空纬向急流,急流中心位于300m高度处;极锋上空低空风速强而高空风速弱.%During the 25th Chinese Antarctic expedition, a new GPS radiosonde system was launched to detect the vertical structure of the atmosphere around the southeast Indian Ocean fronts region. Detailed information on the vertical profiles of wind speed and air temperature above the fronts between the Chinese Antarctic station, Zhongshan and the port of Fremantle, Australia, was obtained. The research showed that a distinct vertical structure appeared at the warm/cold side of the sub-Antarctic front between Zhongshan Station and Fremantle. The low level wind speed at the warm side was stronger than at the cold side, a finding that confirmed the special atmosphere-ocean interaction at the front area in the southeast Indian Ocean region. A low-level jet was observed above the sub-Antarctic front between Zhongshan Station and Fremantle. The vertical structure of the atmosphere around the Antarctic front was quite different compared with the sub-Antarctic front.

  8. Model-Assisted Control of Flow Front in Resin Transfer Molding Based on Real-Time Estimation of Permeability/Porosity Ratio

    Directory of Open Access Journals (Sweden)

    Bai-Jian Wei

    2016-09-01

    Full Text Available Resin transfer molding (RTM is a popular manufacturing technique that produces fiber reinforced polymer (FRP composites. In this paper, a model-assisted flow front control system is developed based on real-time estimation of permeability/porosity ratio using the information acquired by a visualization system. In the proposed control system, a radial basis function (RBF network meta-model is utilized to predict the position of the future flow front by inputting the injection pressure, the current position of flow front, and the estimated ratio. By conducting optimization based on the meta-model, the value of injection pressure to be implemented at each step is obtained. Moreover, a cascade control structure is established to further improve the control performance. Experiments show that the developed system successfully enhances the performance of flow front control in RTM. Especially, the cascade structure makes the control system robust to model mismatch.

  9. Massively parallel energy space exploration for uncluttered visualization of vascular structures.

    Science.gov (United States)

    Jeon, Yongkweon; Won, Joong-Ho; Yoon, Sungroh

    2013-01-01

    Images captured using computed tomography and magnetic resonance angiography are used in the examination of the abdominal aorta and its branches. The examination of all clinically relevant branches simultaneously in a single 2-D image without any misleading overlaps facilitates the diagnosis of vascular abnormalities. This problem is called uncluttered single-image visualization (USIV). We can solve the USIV problem by assigning energy-based scores to visualization candidates and then finding the candidate that optimizes the score; this approach is similar to the manner in which the protein side-chain placement problem has been solved. To obtain near-optimum images, we need to explore the energy space extensively, which is often time consuming. This paper describes a method for exploring the energy space in a massively parallel fashion using graphics processing units. According to our experiments, in which we used 30 images obtained from five patients, the proposed method can reduce the total visualization time substantially. We believe that the proposed method can make a significant contribution to the effective visualization of abdominal vascular structures and precise diagnosis of related abnormalities.

  10. Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention.

    Science.gov (United States)

    Nielsen, Simon; Wilms, L Inge

    2014-01-01

    We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60-75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path analyses in SEM (Model 1). The results show that aging effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM) capacity (Model 2). These results are consistent with some studies reporting selective aging effects on processing speed, and inconsistent with other studies reporting aging effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive aging effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent.

  11. Cognitive ageing on latent constructs for visual processing capacity: A novel Structural Equation Modelling framework with causal assumptions based on A Theory of Visual Attention

    Directory of Open Access Journals (Sweden)

    Simon eNielsen

    2015-01-01

    Full Text Available We examined the effects of normal ageing on visual cognition in a sample of 112 healthy adults aged 60-75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive ageing affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modelling (SEM; Model 2, informed by functional structures that were modelled with path analyses in SEM (Model 1. The results show that ageing effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM capacity (Model 2. These results are consistent with some studies reporting selective ageing effects on processing speed, and inconsistent with other studies reporting ageing effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive ageing effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent.

  12. Visual assessment of soil structure quality in an agroextractivist system in Southeastern Amazonia

    Science.gov (United States)

    Fernanda Simões da Silva, Laura; Stuchi Boschi, Raquel; Ortega Gomes, Matheus; Cooper, Miguel

    2016-04-01

    Soil structure is considered a key factor in the functioning of soil, affecting its ability to support plant and animal life, and moderate environmental quality. Numerous methods are available to evaluate soil structure based on physical, chemical and biological indicators. Among the physical indicators, the attributes most commonly used are soil bulk density, porosity, soil resistance to penetration, tensile strength of aggregates, soil water infiltration, and available water. However, these methods are expensive and generally time costly for sampling and laboratorial procedures. Recently, evaluations using qualitative and semi-quantitative indicators of soil structure quality have gained importance. Among these methods, the method known as Visual Evaluation of Soil Structure (VESS) (Ball et al., 2007; Guimarães et al., 2011) can supply this necessity in temperate and tropical regions. The study area is located in the Piranheira Praialta Agroextrativist Settlement Project in the county of Nova Ipixuna, Pará, Brazil. Two toposequences were chosen, one under native forest and the other under pasture. Pits were opened in different landscape positions (upslope, midslope and downslope) for soil morphological, micromorphological and physical characterization. The use of the soil visual evaluation method (SVE) consisted in collecting an undisturbed soil sample of approximately 25 cm in length, 20 cm in width and 10 cm in depth. 12 soil samples were taken for each land use. The samples were manually fragmented, respecting the fracture planes between the aggregates. The SVE was done comparing the fragmented sample with a visual chart and scores were given to the soil structure. The categories that define the soil structure quality (Qe) vary from 1 to 5. Lower scores mean better soil structure. The final score calculation was done using the classification key of Ball et al. (2007) adapted by Guimarães (2011). A change in soil structure was observed between forest and

  13. Structural and functional correlates of visual field asymmetry in the human brain by diffusion kurtosis MRI and functional MRI.

    Science.gov (United States)

    O'Connell, Caitlin; Ho, Leon C; Murphy, Matthew C; Conner, Ian P; Wollstein, Gadi; Cham, Rakie; Chan, Kevin C

    2016-11-09

    Human visual performance has been observed to show superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine whether the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI, respectively, in 15 healthy individuals at 3 T. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In diffusion kurtosis MRI, the brain regions mapping to the lower visual field showed higher mean kurtosis, but not fractional anisotropy or mean diffusivity compared with the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing.

  14. Light-Front Holography and the Light-Front Schrodinger Equation

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; de Teramond, Guy

    2012-08-15

    One of the most important nonperturbative methods for solving QCD is quantization at fixed light-front time {tau} = t+z=c - Dirac's 'Front Form'. The eigenvalues of the light-front QCD Hamiltonian predict the hadron spectrum and the eigensolutions provide the light-front wavefunctions which describe hadron structure. More generally, we show that the valence Fock-state wavefunctions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schrodinger equation, with an effective confining potential U which systematically incorporates the effects of higher quark and gluon Fock states. We outline a method for computing the required potential from first principles in QCD. The holographic mapping of gravity in AdS space to QCD, quantized at fixed light-front time, yields the same light front Schrodinger equation; in fact, the soft-wall AdS/QCD approach provides a model for the light-front potential which is color-confining and reproduces well the light-hadron spectrum. One also derives via light-front holography a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The elastic and transition form factors of the pion and the nucleons are found to be well described in this framework. The light-front AdS/QCD holographic approach thus gives a frame-independent first approximation of the color-confining dynamics, spectroscopy, and excitation spectra of relativistic light-quark bound states in QCD.

  15. Design Trends in U.S. Front Pages, 1885-1985.

    Science.gov (United States)

    Barnhurst, Kevin G.; Nerone, John C.

    1991-01-01

    Analyzes the visual form of three newspapers' front pages from 1885 to 1985. Finds that front pages became a more uniform, more efficient map of the news. Concludes that ideas behind this "design revolution" (with their sources in design theory and news ideology rather than in economics or technology) have been influencing front pages…

  16. Measures of visual pathway structure and function in MS: Clinical usefulness and role for MS trials.

    Science.gov (United States)

    Galetta, Kristin M; Balcer, Laura J

    2013-07-01

    Over the past decade, the visual pathway in multiple sclerosis (MS) has become an important system for assessing both patient function and disease burden. Abnormalities of low-contrast acuity, long recognized as important correlates of driving, facial recognition, and other activities of daily living, are now noted to be common among patients with MS, even among those with no history of acute optic neuritis (ON). Low-contrast letter acuity scores correlate well with brain MRI lesion burden, visual-evoked potential (VEP) amplitudes, health-related quality of life (QOL), and retinal nerve fiber layer (RNFL) axonal and neuronal loss as measured by optical coherence tomography (OCT). Axonal and neuronal degeneration in MS is likely to be an important cause of visual impairment and disability, particularly among patients with progressive MS subtypes. With the advent of OCT and the use of low-contrast letter acuity charts in MS research and clinical trials, the structure-function correlations afforded by the anterior visual pathway can be assessed and potentially harnessed as a model for testing new therapies. Recent advances in OCT, such as high resolution spectral-domain techniques and computerized algorithms for image analysis, have allowed for measurement of specific retinal layers, including the ganglion cell (GCL) neuronal layer and its intimately associated, thin layer of interneurons, the inner plexiform layer (IPL). Longitudinal collaborative studies of GCL+IPL thinning and RNFL axonal loss are providing an in vivo view into neuroretinal pathology, and are providing new insights into how the visual pathway may reflect overall mechanisms of disease in MS. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Real-Time Impact Visualization Inspection of Aerospace Composite Structures with Distributed Sensors.

    Science.gov (United States)

    Si, Liang; Baier, Horst

    2015-07-08

    For the future design of smart aerospace structures, the development and application of a reliable, real-time and automatic monitoring and diagnostic technique is essential. Thus, with distributed sensor networks, a real-time automatic structural health monitoring (SHM) technique is designed and investigated to monitor and predict the locations and force magnitudes of unforeseen foreign impacts on composite structures and to estimate in real time mode the structural state when impacts occur. The proposed smart impact visualization inspection (IVI) technique mainly consists of five functional modules, which are the signal data preprocessing (SDP), the forward model generator (FMG), the impact positioning calculator (IPC), the inverse model operator (IMO) and structural state estimator (SSE). With regard to the verification of the practicality of the proposed IVI technique, various structure configurations are considered, which are a normal CFRP panel and another CFRP panel with "orange peel" surfaces and a cutout hole. Additionally, since robustness against several background disturbances is also an essential criterion for practical engineering demands, investigations and experimental tests are carried out under random vibration interfering noise (RVIN) conditions. The accuracy of the predictions for unknown impact events on composite structures using the IVI technique is validated under various structure configurations and under changing environmental conditions. The evaluated errors all fall well within a satisfactory limit range. Furthermore, it is concluded that the IVI technique is applicable for impact monitoring, diagnosis and assessment of aerospace composite structures in complex practical engineering environments.

  18. Combining Dense Structure From Motion and Visual SLAM in a Behavior-Based Robot Control Architecture

    Directory of Open Access Journals (Sweden)

    Geert De Cubber

    2010-02-01

    Full Text Available In this paper, we present a control architecture for an intelligent outdoor mobile robot. This enables the robot to navigate in a complex, natural outdoor environment, relying on only a single on-board camera as sensory input. This is achieved through a twofold analysis of the visual data stream: a dense structure from motion algorithm calculates a depth map of the environment and a visual simultaneous localization and mapping algorithm builds a map of the surroundings using image features. This information enables a behavior-based robot motion and path planner to navigate the robot through the environment. In this paper, we show the theoretical aspects of setting up this architecture.

  19. Music in film and animation: experimental semiotics applied to visual, sound and musical structures

    Science.gov (United States)

    Kendall, Roger A.

    2010-02-01

    The relationship of music to film has only recently received the attention of experimental psychologists and quantificational musicologists. This paper outlines theory, semiotical analysis, and experimental results using relations among variables of temporally organized visuals and music. 1. A comparison and contrast is developed among the ideas in semiotics and experimental research, including historical and recent developments. 2. Musicological Exploration: The resulting multidimensional structures of associative meanings, iconic meanings, and embodied meanings are applied to the analysis and interpretation of a range of film with music. 3. Experimental Verification: A series of experiments testing the perceptual fit of musical and visual patterns layered together in animations determined goodness of fit between all pattern combinations, results of which confirmed aspects of the theory. However, exceptions were found when the complexity of the stratified stimuli resulted in cognitive overload.

  20. Image size invariant visual cryptography for general access structures subject to display quality constraints.

    Science.gov (United States)

    Lee, Kai-Hui; Chiu, Pei-Ling

    2013-10-01

    Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

  1. Interactive Simulation and Visualization of Lamb Wave Propagation in Isotropic and Anisotropic Structures

    Energy Technology Data Exchange (ETDEWEB)

    Moll, J; Schulte, R T; Fritzen, C-P [Institute of Mechanics and Control Engineering - Mechatronics, University of Siegen (Germany); Rezk-Salama, C [Mediadesign University of Applied Science Duesseldorf (Germany); Klinkert, T; Kolb, A, E-mail: moll@imr.mb.uni-siegen.de [Computer Graphics and Multimedia Systems, University of Siegen (Germany)

    2011-07-19

    Structural health monitoring systems allow a continuous surveillance of the structural integrity of operational systems. As a result, it is possible to reduce time and costs for maintenance without decreasing the level of safety. In this paper, an integrated simulation and visualization environment is presented that enables a detailed study of Lamb wave propagation in isotropic and anisotropic materials. Thus, valuable information about the nature of Lamb wave propagation and its interaction with structural defects become available. The well-known spectral finite element method is implemented to enable a time-efficient calculation of the wave propagation problem. The results are displayed in an interactive visualization framework accounting for the human perception that is much more sensitive to motion than to changes in color. In addition, measurements have been conducted experimentally to record the full out-of-plane wave-field using a Laser-Doppler vibrometry setup. An aluminum structure with two synthetic cuts has been investigated, where the elongated defects have a different orientation with respect to the piezoelectric actuator. The resulting wave-field is also displayed interactively showing that the scattered wave-field at the defect is highly directional.

  2. Discovering anatomical patterns with pathological meaning by clustering of visual primitives in structural brain MRI

    Science.gov (United States)

    Leon, Juan; Pulido, Andrea; Romero, Eduardo

    2015-01-01

    Computational anatomy is a subdiscipline of the anatomy that studies macroscopic details of the human body structure using a set of automatic techniques. Different reference systems have been developed for brain mapping and morphometry in functional and structural studies. Several models integrate particular anatomical regions to highlight pathological patterns in structural brain MRI, a really challenging task due to the complexity, variability, and nonlinearity of the human brain anatomy. In this paper, we present a strategy that aims to find anatomical regions with pathological meaning by using a probabilistic analysis. Our method starts by extracting visual primitives from brain MRI that are partitioned into small patches and which are then softly clustered, forming different regions not necessarily connected. Each of these regions is described by a co- occurrence histogram of visual features, upon which a probabilistic semantic analysis is used to find the underlying structure of the information, i.e., separated regions by their low level similarity. The proposed approach was tested with the OASIS data set which includes 69 Alzheimer's disease (AD) patients and 65 healthy subjects (NC).

  3. Versatile morphometric analysis and visualization of the three-dimensional structure of neurons.

    Science.gov (United States)

    Aguiar, Paulo; Sousa, Mafalda; Szucs, Peter

    2013-10-01

    The computational properties of a neuron are intimately related to its morphology. However, unlike electrophysiological properties, it is not straightforward to collapse the complexity of the three-dimensional (3D) structure into a small set of measurements accurately describing the structural properties. This strong limitation leads to the fact that many studies involving morphology related questions often rely solely on empirical analysis and qualitative description. It is possible however to acquire hierarchical lists of positions and diameters of points describing the spatial structure of the neuron. While there is a number of both commercially and freely available solutions to import and analyze this data, few are extendable in the sense of providing the possibility to define novel morphometric measurements in an easy to use programming environment. Fewer are capable of performing morphometric analysis where the output is defined over the topology of the neuron, which naturally requires powerful visualization tools. The computer application presented here, Py3DN, is an open-source solution providing novel tools to analyze and visualize 3D data collected with the widely used Neurolucida (MBF) system. It allows the construction of mathematical representations of neuronal topology, detailed visualization and the possibility to define non-standard morphometric analysis on the neuronal structures. Above all, it provides a flexible and extendable environment where new types of analyses can be easily set up allowing a high degree of freedom to formulate and test new hypotheses. The application was developed in Python and uses Blender (open-source software) to produce detailed 3D data representations.

  4. (Pea)nuts and bolts of visual narrative: structure and meaning in sequential image comprehension.

    Science.gov (United States)

    Cohn, Neil; Paczynski, Martin; Jackendoff, Ray; Holcomb, Phillip J; Kuperberg, Gina R

    2012-08-01

    . Altogether, we argue that the comprehension of visual narrative is guided by an interaction between structure and meaning.

  5. Experimental Study on Local Mass Transfer of Structured Packing with the Method of Flow Visualization

    Institute of Scientific and Technical Information of China (English)

    张燕来; 朱慧铭; 尹秋响

    2011-01-01

    A chromochemical reactive mass transfer technique has been employed to study local mass transfer characteristics of structured packing. This technology adopted by experiment is an Ammonia Adsorption Method (AAM) that yields the surface distribution of transferred mass by analyzing the color distribution on a filter paper with the results of the color chemical reaction. A digital image processing technology is applied for data visualiza-tion. The three-dimensional plot of the local mass transfer coefficients shows that there exist three peak values on different positions of a unit cell of structured packing. In order to improve mass transfer efficiency of the structured packing, one piece of baffle is added between packing sheets. As a result, the average mass transfer coefficient increases by (10 20)% and the pressure drop decreases by (15-55)%.

  6. Foundations of computer vision computational geometry, visual image structures and object shape detection

    CERN Document Server

    Peters, James F

    2017-01-01

    This book introduces the fundamentals of computer vision (CV), with a focus on extracting useful information from digital images and videos. Including a wealth of methods used in detecting and classifying image objects and their shapes, it is the first book to apply a trio of tools (computational geometry, topology and algorithms) in solving CV problems, shape tracking in image object recognition and detecting the repetition of shapes in single images and video frames. Computational geometry provides a visualization of topological structures such as neighborhoods of points embedded in images, while image topology supplies us with structures useful in the analysis and classification of image regions. Algorithms provide a practical, step-by-step means of viewing image structures. The implementations of CV methods in Matlab and Mathematica, classification of chapter problems with the symbols (easily solved) and (challenging) and its extensive glossary of key words, examples and connections with the fabric of C...

  7. Efficient blood flow visualization using flowline extraction and opacity modulation based on vascular structure analysis.

    Science.gov (United States)

    Kwon, Ohjae; Lee, Jeongjin; Kim, Bohyoung; Shin, Juneseuk; Shin, Yeong-Gil

    2017-03-01

    With the recent advances regarding the acquisition and simulation of blood flow data, blood flow visualization has been widely used in medical imaging for the diagnosis and treatment of pathological vessels. In this paper, we present a novel method for the visualization of the blood flow in vascular structures. The vessel inlet or outlet is first identified using the orthogonality metric between the normal vectors of the flow velocity and vessel surface. Then, seed points are generated on the identified inlet or outlet by Poisson disk sampling. Therefore, it is possible to achieve the automatic seeding that leads to a consistent and faster flow depiction by skipping the manual location of a seeding plane for the initiation of the line integration. In addition, the early terminated line integration in the thin curved vessels is resolved through the adaptive application of the tracing direction that is based on the flow direction at each seed point. Based on the observation that blood flow usually follows the vessel track, the representative flowline for each branch is defined by the vessel centerline. Then, the flowlines are rendered through an opacity assignment according to the similarity between their shape and the vessel centerline. Therefore, the flowlines that are similar to the vessel centerline are shown transparently, while the different ones are shown opaquely. Accordingly, the opacity modulation method enables the flowlines with an unusual flow pattern to appear more noticeable, while the visual clutter and line occlusion are minimized. Finally, Hue-Saturation-Value color coding is employed for the simultaneous exhibition of flow attributes such as local speed and residence time. The experiment results show that the proposed technique is suitable for the depiction of the blood flow in vascular structures. The proposed approach is applicable to many kinds of tubular structures with embedded flow information.

  8. Chemozart: a web-based 3D molecular structure editor and visualizer platform.

    Science.gov (United States)

    Mohebifar, Mohamad; Sajadi, Fatemehsadat

    2015-01-01

    Chemozart is a 3D Molecule editor and visualizer built on top of native web components. It offers an easy to access service, user-friendly graphical interface and modular design. It is a client centric web application which communicates with the server via a representational state transfer style web service. Both client-side and server-side application are written in JavaScript. A combination of JavaScript and HTML is used to draw three-dimensional structures of molecules. With the help of WebGL, three-dimensional visualization tool is provided. Using CSS3 and HTML5, a user-friendly interface is composed. More than 30 packages are used to compose this application which adds enough flexibility to it to be extended. Molecule structures can be drawn on all types of platforms and is compatible with mobile devices. No installation is required in order to use this application and it can be accessed through the internet. This application can be extended on both server-side and client-side by implementing modules in JavaScript. Molecular compounds are drawn on the HTML5 Canvas element using WebGL context. Chemozart is a chemical platform which is powerful, flexible, and easy to access. It provides an online web-based tool used for chemical visualization along with result oriented optimization for cloud based API (application programming interface). JavaScript libraries which allow creation of web pages containing interactive three-dimensional molecular structures has also been made available. The application has been released under Apache 2 License and is available from the project website https://chemozart.com.

  9. Factor structure of the human gamma band oscillatory response to visual (contrast) stimulation.

    Science.gov (United States)

    Carozzo, Simone; De Carli, Fabrizio; Beelke, Manolo; Saturno, Moreno; Garbarino, Sergio; Martello, Cristina; Sannita, Walter G

    2004-07-01

    Visual contrast stimulation evokes in man an oscillatory mass response at approximately 20.0-35.0 Hz, consistent with stimulus-dependent synchronous oscillations in multiunit animal recordings from visual cortex, but shorter in duration and phase-locked to stimulus. A factor analysis was applied to characterize the signal structure under stimulus conditions inducing an oscillatory response and to identify possible subcomponents in normal volunteers. Contrast stimuli were gratings with a sinusoidal luminance profile (9.0 degrees; 5.0 cycle/degree; 80% contrast; reversal 1.06 Hz). The amplitude spectrum of the signal was computed by Discrete Fourier Transform (DFT) and the oscillatory response was separated from the corresponding visually evoked potential (VEP) by DFT high-pass filter at 19.0 Hz. Nine consecutive waves were identified in all subjects (60 volunteers), with amplitudes/latencies consistent with normative studies. A factor analysis was computed 1- in the frequency domain, on the amplitude values of the signal components (2 Hz resolution), and 2- in the time domain, on the latencies/amplitudes of the averaged VEP and oscillatory responses. (1) Two non-overlapping factors accounted for the approximately 2-20.0 and approximately 20.0-40.0 Hz signal components, with separation of the approximately 20.0-35.0 Hz oscillatory response from low frequency VEPs. (2) Two factors on latencies and one factor on amplitudes (independent of each other and from those of VEPs) accounted for the average approximately 20.0-35.0 Hz oscillatory response. The factor structure further indicates an oscillatory structure and some independence from conventional VEPs of the human oscillatory response to contrast, with a separation between the oscillatory response early and late waves possibly reflecting functional differences.

  10. Autofluorescence imaging for improved visualization of joint structures during arthroscopic surgery.

    Science.gov (United States)

    Nguyen, Duy Tan; van Horssen, Pepijn; Derriks, Hans; van de Giessen, Martijn; van Leeuwen, Ton

    2017-12-01

    The purpose of our study is to develop the arthroscopic autofluorescence imaging (AFI) system to improve the visualization during arthroscopic surgery by real-time enhancing the contrast between joint structures with autofluorescence imaging. Its validity was evaluated around the arthroscopic anterior cruciate ligament (ACL) reconstruction, specifically improving the contrast between the femoral insertion site and its background. The feasibility of the AFI system was validated with bovine and human knees. The spectral responses of the femoral insertion site and its surrounding bone and cartilage were measured with a fluorospectrometer. A prototype of the AFI system was developed based on the spectral responses (SR) and test images of the insertion site. The accuracy was validated by evaluating the overlap between manually segmented insertion sites on the white light color images and on the corresponding spectral unmixed autofluorescence images. The final prototype of the AFI system was tested during arthroscopy in cadaveric knees. The results showed that the joint structures have different SRs. Spectral unmixing enabled separation of the SRs and improved the contrast between the joint structures. The agreement between visible light and autofluorescence ligament insertions had a mean Dice coefficient of 0.84 and the mean Dice coefficient of the interobserver variability for visible light imaging was 0.85. We have shown that the femoral insertion site can be accurately visualized with autofluorescence imaging combined with spectral unmixing. The AFI system demonstrates the feasibility of real-time and subject-specific visualization of the femoral insertion site which can facilitate anatomic ACL reconstruction. In addition, the AFI system can facilitate arthroscopic procedures in other joints and can also be used as a diagnostic tool.

  11. Multispectral Enhancement Method to Increase the Visual Differences of Tissue Structures in Stained Histopathology Images

    Directory of Open Access Journals (Sweden)

    Pinky A. Bautista

    2012-01-01

    Full Text Available In this paper we proposed a multispectral enhancement scheme in which the spectral colors of the stained tissue-structure of interest and its background can be independently modified by the user to further improve their visualization and color discrimination. The colors of the background objects are modified by transforming their N-band spectra through an NxN transformation matrix, which is derived by mapping the representative samples of their original spectra to the spectra of their target colors using least mean square method. On the other hand, the color of the tissue structure of interest is modified by modulating the transformed spectra with the sum of the pixel’s spectral residual-errors at specific bands weighted through an NxN weighting matrix; the spectral error is derived by taking the difference between the pixel’s original spectrum and its reconstructed spectrum using the first M dominant principal component vectors in principal component analysis. Promising results were obtained on the visualization of the collagen fiber and the non-collagen tissue structures, e.g., nuclei, cytoplasm and red blood cells (RBC, in a hematoxylin and eosin (H&E stained image.

  12. VizPrimer: a web server for visualized PCR primer design based on known gene structure.

    Science.gov (United States)

    Zhou, Yang; Qu, Wubin; Lu, Yiming; Zhang, Yanchun; Wang, Xiaolei; Zhao, Dongsheng; Yang, Yi; Zhang, Chenggang

    2011-12-15

    The visualization of gene structure plays an important role in polymerase chain reaction (PCR) primer design, especially for eukaryotic genes with a number of splice variants that users need to distinguish between via PCR. Here, we describe a visualized web server for primer design named VizPrimer. It utilizes the new information technology (IT) tools, HTML5 to display gene structure and JavaScript to interact with the users. In VizPrimer, the users can focus their attention on the gene structure and primer design strategy, without wasting time calculating the exon positions of splice variants or manually configuring complicated parameters. In addition, VizPrimer is also suitable for the design of PCR primers for amplifying open reading frames and detecting single nucleotide polymorphisms (SNPs). VizPrimer is freely available at http://biocompute.bmi.ac.cn/CZlab/VizPrimer/. The web server supported browsers: Chrome (≥5.0), Firefox (≥3.0), Safari (≥4.0) and Opera (≥10.0). zhangcg@bmi.ac.cn; yangyi528@vip.sina.com.

  13. Visualizing viral protein structures in cells using genetic probes for correlated light and electron microscopy.

    Science.gov (United States)

    Ou, Horng D; Deerinck, Thomas J; Bushong, Eric; Ellisman, Mark H; O'Shea, Clodagh C

    2015-11-15

    Structural studies of viral proteins most often use high-resolution techniques such as X-ray crystallography, nuclear magnetic resonance, single particle negative stain, or cryo-electron microscopy (EM) to reveal atomic interactions of soluble, homogeneous viral proteins or viral protein complexes. Once viral proteins or complexes are separated from their host's cellular environment, their natural in situ structure and details of how they interact with other cellular components may be lost. EM has been an invaluable tool in virology since its introduction in the late 1940's and subsequent application to cells in the 1950's. EM studies have expanded our knowledge of viral entry, viral replication, alteration of cellular components, and viral lysis. Most of these early studies were focused on conspicuous morphological cellular changes, because classic EM metal stains were designed to highlight classes of cellular structures rather than specific molecular structures. Much later, to identify viral proteins inducing specific structural configurations at the cellular level, immunostaining with a primary antibody followed by colloidal gold secondary antibody was employed to mark the location of specific viral proteins. This technique can suffer from artifacts in cellular ultrastructure due to compromises required to provide access to the immuno-reagents. Immunolocalization methods also require the generation of highly specific antibodies, which may not be available for every viral protein. Here we discuss new methods to visualize viral proteins and structures at high resolutions in situ using correlated light and electron microscopy (CLEM). We discuss the use of genetically encoded protein fusions that oxidize diaminobenzidine (DAB) into an osmiophilic polymer that can be visualized by EM. Detailed protocols for applying the genetically encoded photo-oxidizing protein MiniSOG to a viral protein, photo-oxidation of the fusion protein to yield DAB polymer staining, and

  14. Graph visualization for the analysis of the structure and dynamics of extreme-scale supercomputers

    Energy Technology Data Exchange (ETDEWEB)

    Berkbigler, K. P. (Kathryn P.); Bush, B. W. (Brian W.); Davis, Kei,; Hoisie, A. (Adolfy); Smith, S. A. (Steve A.)

    2002-01-01

    We are exploring the development and application of information visualization techniques for the analysis of new extreme-scale supercomputer architectures. Modern supercomputers typically comprise very large clusters of commodity SMPs interconnected by possibly dense and often nonstandard networks. The scale, complexity, and inherent nonlocality of the structure and dynamics of this hardware, and the systems and applications distributed over it, challenge traditional analysis methods. As part of the a la carte team at Los Alamos National Laboratory, who are simulating these advanced architectures, we are exploring advanced visualization techniques and creating tools to provide intuitive exploration, discovery, and analysis of these simulations. This work complements existing and emerging algorithmic analysis tools. Here we gives background on the problem domain, a description of a prototypical computer architecture of interest (on the order of 10,000 processors connected by a quaternary fat-tree network), and presentations of several visualizations of the simulation data that make clear the flow of data in the interconnection network.

  15. seeMotif: exploring and visualizing sequence motifs in 3D structures

    Science.gov (United States)

    Chang, Darby Tien-Hao; Chien, Ting-Ying; Chen, Chien-Yu

    2009-01-01

    Sequence motifs are important in the study of molecular biology. Motif discovery tools efficiently deliver many function related signatures of proteins and largely facilitate sequence annotation. As increasing numbers of motifs are detected experimentally or predicted computationally, characterizing the functional roles of motifs and identifying the potential synergetic relationships between them are important next steps. A good way to investigate novel motifs is to utilize the abundant 3D structures that have also been accumulated at an astounding rate in recent years. This article reports the development of the web service seeMotif, which provides users with an interactive interface for visualizing sequence motifs on protein structures from the Protein Data Bank (PDB). Researchers can quickly see the locations and conformation of multiple motifs among a number of related structures simultaneously. Considering the fact that PDB sequences are usually shorter than those in sequence databases and/or may have missing residues, seeMotif has two complementary approaches for selecting structures and mapping motifs to protein chains in structures. As more and more structures belonging to previously uncharacterized protein families become available, combining sequence and structure information gives good opportunities to facilitate understanding of protein functions in large-scale genome projects. Available at: http://seemotif.csie.ntu.edu.tw,http://seemotif.ee.ncku.edu.tw or http://seemotif.csbb.ntu.edu.tw. PMID:19477961

  16. seeMotif: exploring and visualizing sequence motifs in 3D structures.

    Science.gov (United States)

    Chang, Darby Tien-Hao; Chien, Ting-Ying; Chen, Chien-Yu

    2009-07-01

    Sequence motifs are important in the study of molecular biology. Motif discovery tools efficiently deliver many function related signatures of proteins and largely facilitate sequence annotation. As increasing numbers of motifs are detected experimentally or predicted computationally, characterizing the functional roles of motifs and identifying the potential synergetic relationships between them are important next steps. A good way to investigate novel motifs is to utilize the abundant 3D structures that have also been accumulated at an astounding rate in recent years. This article reports the development of the web service seeMotif, which provides users with an interactive interface for visualizing sequence motifs on protein structures from the Protein Data Bank (PDB). Researchers can quickly see the locations and conformation of multiple motifs among a number of related structures simultaneously. Considering the fact that PDB sequences are usually shorter than those in sequence databases and/or may have missing residues, seeMotif has two complementary approaches for selecting structures and mapping motifs to protein chains in structures. As more and more structures belonging to previously uncharacterized protein families become available, combining sequence and structure information gives good opportunities to facilitate understanding of protein functions in large-scale genome projects. Available at: http://seemotif.csie.ntu.edu.tw,http://seemotif.ee.ncku.edu.tw or http://seemotif.csbb.ntu.edu.tw.

  17. Visual product architecture modelling for structuring data in a PLM system

    DEFF Research Database (Denmark)

    Bruun, Hans Peter Lomholt; Mortensen, Niels Henrik

    2012-01-01

    The goal of this paper is to determine the role of a product architecture model to support communication and to form the basis for developing and maintaining information of product structures in a PLM system. This paper contains descriptions of a modelling tool to represent a product architecture....... Moreover, it is discussed how the sometimes intangible elements and phenomena within an architecture model can be visually modeled in order to form the basis for a data model in a PLM system. © 2012 International Federation for Information Processing....

  18. A visual assessment of vegetation structure for the Kruger National Park

    Directory of Open Access Journals (Sweden)

    A.C. Kemp

    1997-02-01

    Full Text Available Vegetation structure was assessed visually for 1045 of the 1093 quadrats (2.5' x 2.5', ca 4 x 4 km that cover the Kruger National Park. Vegetation categories recorded were-woody vegetation (broad-leaved, mopane, fine-leaved, mixed, riparian, treeless, scrub bushes and trees; ground cover (grass, grassless and open areas; and emergent large trees (baobab, live and dead. The results are available as grid maps or as files on the Internet. The categories were selected for their relevance to bird distribution but can be applied to other organisms.

  19. Real-Time Visualization of Platelet Interaction With Micro Structured Surfaces.

    Science.gov (United States)

    Gester, Kathrin; Birtel, Stephan; Clauser, Johanna; Steinseifer, Ulrich; Sonntag, Simon Johannes

    2016-02-01

    Improving the hemocompatibility of artificial implants by micro structuring their surfaces has shown promising results, but the mechanisms which lead to this improvement are not yet understood. Therefore, we built a test setup for real-time visualization of platelet interaction with a plain and two micro structured surfaces. The micro structures, defined by the distance of the plain surface area between the structures, were chosen to be 3 and 30 μm, representing a positive and a negative effect on the hemocompatibility. The main part of the test setup was a flow chamber containing films of low density polyethylene (LDPE) with the differently structured surfaces. For different wall shear stresses, no considerable differences were observed in the platelet-surface interaction for all surface types. Whereas, major differences in flow behavior were observed when comparing the surfaces to each other. The platelets "rolled" along the smooth surface, being in constant contact with the surface material. Although the platelets "rolled" over the surface with small structures as well, they were only in contact with the tips of the structure and therefore had less surface contact with the foreign material. The increased distance and height of the structures of the last surface led to a trapping of platelets between the structures. This resulted in a longer contact time with the foreign material as well as a larger contact area, which both increase the risk of platelet activation, adhesion, and finally clotting. Our results showed the mechanisms which lead to these effects and thus revealed why micro structuring of surfaces impacts the hemocompatibility. Furthermore, we established a test setup which can be used for future investigations on the platelet-structure interactions.

  20. Light-Front QCD

    CERN Document Server

    Brodsky, S J

    2004-01-01

    In these lectures, I survey a number of applications of light-front methods to hadron and nuclear physics phenomenology and dynamics, Light-front Fock-state wavefunctions provide a frame-independent representation of hadrons in terms of their fundamental quark and gluon degrees of freedom. Nonperturbative methods for computing LFWFs in QCD are discussed, including string/gauge duality which predicts the power-law fall-off at high momentum transfer of light-front Fock-state hadronic wavefunctions with an arbitrary number of constituents and orbital angular momentum. The AdS/CFT correspondence has important implications for hadron phenomenology in the conformal limit, including an all-orders derivation of counting rules for exclusive processes. One can also compute the hadronic spectrum of near-conformal QCD assuming a truncated AdS/CFT space. The quantum fluctuations represented by the light-front Fock expansion leads to novel QCD phenomena such as color transparency, intrinsic heavy quark distributions, diffr...

  1. Structural imprints at the front of the Chocó-Panamá indenter: Field data from the North Cauca Valley Basin, Central Colombia

    Science.gov (United States)

    Suter, F.; Sartori, M.; Neuwerth, R.; Gorin, G.

    2008-11-01

    The northern Andes are a complex area where tectonics is dominated by the interaction between three major plates and accessory blocks, in particular, the Chocó-Panamá and Northern Andes Blocks. The studied Cauca Valley Basin is located at the front of the Chocó-Panamá Indenter, where the major Romeral Fault System, active since the Cretaceous, changes its kinematics from right-lateral in the south to left-lateral in the north. Structural studies were performed at various scales: DEM observations in the Central Cordillera between 4 and 5.7°N, aerial photograph analyses, and field work in the folded Oligo-Miocene rocks of the Serranía de Santa Barbara and in the flat-lying, Pleistocene Quindío-Risaralda volcaniclastic sediments interfingering with the lacustrine to fluviatile sediments of the Zarzal Formation. The data acquired allowed the detection of structures with a similar orientation at every scale and in all lithologies. These families of structures are arranged similarly to Riedel shears in a right-lateral shear zone and are superimposed on the Cretaceous Romeral suture. They appear in the Central Cordillera north of 4.5°N, and define a broad zone where 060-oriented right-lateral distributed shear strain affects the continental crust. The Romeral Fault System stays active and strain partitioning occurs among both systems. The southern limit of the distributed shear strain affecting the Central Cordillera corresponds to the E-W trending Garrapatas-Ibagué shear zone, constituted by several right-stepping, en-échelon, right-lateral, active faults and some lineaments. North of this shear zone, the Romeral Fault System strike changes from NNE to N. Paleostress calculations gave a WNW-ESE trending, maximum horizontal stress, and 69% of compressive tensors. The orientation of σ1 is consistent with the orientation of the right-lateral distributed shear strain and the compressive state characterizing the Romeral Fault System in the area: it bisects the

  2. Direct visualization of the formation of a new structure of lambda DNA in vitro

    Institute of Scientific and Technical Information of China (English)

    方晔; 白春礼; 魏莹; 张平城; 唐有祺; 曹恩华; 何裕建

    1995-01-01

    A DNA component(referred to as new DNA structure),which has higher melting point(~ 73.5℃)and is resistant to DNase I-digestion,has suocessfully been isolated from lambda DNA Hind Ⅲtreated by cooling down quickly following thermal denaturation.Transmission electron microscope(TEM)andatomic force microscope(AFM)visualizations of the DNA molecule have shown that their lenghts fall mainly inthree regions(300 — 500 nm,750 — 1 000 nm and ~ 1 500 nm),indicating that longer fragments of λ-DNA HindⅢ are apt to form the new structure of DNA under experimental conditions;moreover,the apparent width inthe middle part of TEM imagesof a few longer molecules of the new structure of DNA is relatively thinner,wwhich may be reasonably deduced from the inhibition of DNase I(an endonuclease)binding to the new struc-ture of DNA.CD spectrum of the new structure contains a broad positive band centred at 245um anda weak negative band at 220 nm,indicating that the DNA molecule is distinctly different from all the known struc-tures of DNA.

  3. Risk factors and visual fatigue of baggage X-ray security screeners: a structural equation modelling analysis.

    Science.gov (United States)

    Yu, Rui-Feng; Yang, Lin-Dong; Wu, Xin

    2016-06-03

    This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue using structural equation modelling approach. Two hundred and five X-ray security screeners participated in a questionnaire survey. The result showed that satisfaction with the VDT's physical features and the work environment conditions were negatively correlated with the intensity of visual fatigue, whereas job stress and job burnout had direct positive influences. The path coefficient between the image quality of VDT and visual fatigue was not significant. The total effects of job burnout, job stress, the VDT's physical features and the work environment conditions on visual fatigue were 0.471, 0.469, -0.268 and -0.251 respectively. These findings indicated that both extrinsic factors relating to VDT and workplace environment and psychological factors including job burnout and job stress should be considered in the workplace design and work organisation of security screening tasks to reduce screeners' visual fatigue. Practitioner Summary: This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue. The findings were of great importance to the workplace design and the work organisation of security screening tasks to reduce screeners' visual fatigue.

  4. The Front Desks of Boston

    Directory of Open Access Journals (Sweden)

    Michael Oshins

    2013-04-01

    Full Text Available The role of hotel front desks has not changed significantly in more than a century. The activities of welcoming guests upon arrival, assisting guests during their stay, and settling accounts upon departure are still the mainstay of the front desk. Although the function of the front desk has remained static, its form has evolved. Front desks now differ widely in terms of aesthetics and, in some cases, even operational patterns. This article offers photographs of numerous hotel front desks in Boston and provides brief commentaries that provide insight about the changing nature of front desk design.

  5. Components of Appearance in the Structure of Perception of Visual Representations of Age

    Directory of Open Access Journals (Sweden)

    Shkurko T.A.

    2015-12-01

    Full Text Available The article discusses the problem of perception of age (one’s own and that of other people, which is regarded as a special case of social perception. The aim of this study was to analyze the components of another person’s appearance in the structure of perception of visual representations of age. For these purposes the authors created a special technique, “Identifying Age through Photo Visualization” (Shkurko T.A., Nikolaeva E. G.. The study enrolled 20 individuals (10 men, 10 women aged 18 to 58 years as “models” (i.e. objects of perception and 60 individuals (47 women and 13 men aged 18 to 77 years as subjects of perception. The paper shows that in the structure of perception of visual representations of age the most important are stable, moderately stable and dynamic components of appearance, among which the stable parameters prevail. The face as the focus of the stable, moderately stable and dynamic components of appearance is the key element of appearance in one’s perception of other people’s age.

  6. Visualization of pairwise and multilocus linkage disequilibrium structure using latent forests.

    Directory of Open Access Journals (Sweden)

    Raphaël Mourad

    Full Text Available Linkage disequilibrium study represents a major issue in statistical genetics as it plays a fundamental role in gene mapping and helps us to learn more about human history. The linkage disequilibrium complex structure makes its exploratory data analysis essential yet challenging. Visualization methods, such as the triangular heat map implemented in Haploview, provide simple and useful tools to help understand complex genetic patterns, but remain insufficient to fully describe them. Probabilistic graphical models have been widely recognized as a powerful formalism allowing a concise and accurate modeling of dependences between variables. In this paper, we propose a method for short-range, long-range and chromosome-wide linkage disequilibrium visualization using forests of hierarchical latent class models. Thanks to its hierarchical nature, our method is shown to provide a compact view of both pairwise and multilocus linkage disequilibrium spatial structures for the geneticist. Besides, a multilocus linkage disequilibrium measure has been designed to evaluate linkage disequilibrium in hierarchy clusters. To learn the proposed model, a new scalable algorithm is presented. It constrains the dependence scope, relying on physical positions, and is able to deal with more than one hundred thousand single nucleotide polymorphisms. The proposed algorithm is fast and does not require phase genotypic data.

  7. Visualization technique for fatigue cracks at steel structures integrating a scanning laser source with piezoelectric sensors

    Science.gov (United States)

    Lee, Changgil; Kim, Ju-Won; Kim, Hyun Uk; Park, Seunghee

    2013-04-01

    In this research, a noncontact nondestructive testing (NDT) method is proposed to detect the fatigue crack and to identify the location of the damage. To achieve this goal, Lamb wave propagation of a plate-like structure is analyzed, which is induced by scanning laser source actuation system. A ND: YAG pulsed laser system is used to generate Lamb wave exerted at the multiple points of the plate and a piezoelectric sensor is installed to measure the structural responses. Multiple time signals measured by the piezoelectric sensor are aligned along the vertical and horizontal axes corresponding to laser impinging points so that 3 dimensional data can be constructed. Then, the 3 dimensional data is sliced along the time axis to visualize the wave propagation. The scattering of Lamb wave due to the damage can be described in the wave propagation image and hence the damage can be localized and quantified. Damage-sensitive features, which are reflected wave from the damage, are clearly extracted by wave-number filtering based on the 3 dimensional Fourier transform of the visualized data. Additional features are extracted by observing different scales of wavelet coefficients so that the time of flight (TOF) of Lamb wave modes can be clearly separated. Steel plates with fatigue cracks are investigated to verify the effectiveness and the robustness of the proposed NDT approach.

  8. Visualizing a Large-Scale Structure of Production Network by N-Body Simulation

    Science.gov (United States)

    Fujiwara, Y.

    Our recent study of a nation-wide production network uncovered acommunity structure, namely how firms are connected by supplier-customer links into tightly-knit groups with high density in intra-groups and with lower connectivity in inter-groups. Here we propose a method to visualize the community structure by a graph layout based on a physical analogy. The layout can be calculated in a practical computation-time and is possible to be accelerated by a special-purpose device of GRAPE (gravity pipeline) developed for astrophysical N-body simulation. We show that the method successfully identifies the communities in a hierarchical way by applying it to the manufacturing sector comprising tenth million nodes and a half million edges. In addition, we discuss several limitations of this method, and propose a possible way to avoid all those problems.

  9. pophelper: an R package and web app to analyse and visualize population structure.

    Science.gov (United States)

    Francis, R M

    2017-01-01

    The pophelper r package and web app are software tools to aid in population structure analyses. They can be used for the analyses and visualization of output generated from population assignment programs such as admixture, structure and tess. Some of the functions include parsing output run files to tabulate data, estimating K using the Evanno method, generating files for clumpp and functionality to create barplots. These functions can be streamlined into standard r analysis workflows. The latest version of the package is available on github (https://github.com/royfrancis/pophelper). An interactive web version of the pophelper package is available which covers the same functionalities as the r package version with features such as interactive plots, cluster alignment during plotting, sorting individuals and ordering of population groups. The interactive version is available at http://pophelper.com/.

  10. Summarizing and visualizing structural changes during the evolution of biomedical ontologies using a Diff Abstraction Network.

    Science.gov (United States)

    Ochs, Christopher; Perl, Yehoshua; Geller, James; Haendel, Melissa; Brush, Matthew; Arabandi, Sivaram; Tu, Samson

    2015-08-01

    Biomedical ontologies are a critical component in biomedical research and practice. As an ontology evolves, its structure and content change in response to additions, deletions and updates. When editing a biomedical ontology, small local updates may affect large portions of the ontology, leading to unintended and potentially erroneous changes. Such unwanted side effects often go unnoticed since biomedical ontologies are large and complex knowledge structures. Abstraction networks, which provide compact summaries of an ontology's content and structure, have been used to uncover structural irregularities, inconsistencies and errors in ontologies. In this paper, we introduce Diff Abstraction Networks ("Diff AbNs"), compact networks that summarize and visualize global structural changes due to ontology editing operations that result in a new ontology release. A Diff AbN can be used to support curators in identifying unintended and unwanted ontology changes. The derivation of two Diff AbNs, the Diff Area Taxonomy and the Diff Partial-area Taxonomy, is explained and Diff Partial-area Taxonomies are derived and analyzed for the Ontology of Clinical Research, Sleep Domain Ontology, and eagle-i Research Resource Ontology. Diff Taxonomy usage for identifying unintended erroneous consequences of quality assurance and ontology merging are demonstrated. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Multidimensional structured data visualization method and apparatus, text visualization method and apparatus, method and apparatus for visualizing and graphically navigating the world wide web, method and apparatus for visualizing hierarchies

    Science.gov (United States)

    Risch, John S.; Dowson, Scott T.; Hart, Michelle L.; Hatley, Wes L.

    2008-05-13

    A method of displaying correlations among information objects comprises receiving a query against a database; obtaining a query result set; and generating a visualization representing the components of the result set, the visualization including one of a plane and line to represent a data field, nodes representing data values, and links showing correlations among fields and values. Other visualization methods and apparatus are disclosed.

  12. Dynamics of curved fronts

    CERN Document Server

    Pelce, Pierre

    1989-01-01

    In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.

  13. Radiative thermal conduction fronts

    Science.gov (United States)

    Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

    1990-01-01

    The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence.

  14. MODEL OF STRUCTURAL-FUNCTIONAL ANALYSIS OF VISUALS IN RUSSIAN ABC BOOKS AND PRIMERS OF LATE XIX - EARLY XX CENTURIES

    Directory of Open Access Journals (Sweden)

    Ivan I. Teterin

    2016-01-01

    Full Text Available Today the prevalence of visual information coding determines the changes in the text and extra-textual components of the textbook, the problem affects the placement and number of illustrative material, defines the relationship and interaction of text and image information, focuses on new forms of organization of the learning process. The movement of humanity from the dominant culture of text oriented logos or the spread and adoption of visual forms of information broadcast began at the turn of the XIX and XX centuries. It was during this period in the academic literature visual components acquired independent didactic value. I began to develop a holistic visual range of a school textbook.The visual tutorial series has been the subject of special study for many scientific disciplines. The overall goal of our research is to answer the question. What didactic features were inherent in visual range of textbooks for initial literacy in Russia in the second half of XIX - early XX century, why, how, and how they changed. In this article, we will focus on the issue of allocation of structural components of the visual range of the spectrum and the functions they perform.Offering a model of this analysis, we relied on the development problems of the textbook functions V. Krajewski, V. Beilinson, I. Lerner, V. Bespal'ko and characteristics of the major structural components of the textbook, the proposed D. Zuev, A. Sochor, J. Mickey and others. 

  15. GeneViTo: Visualizing gene-product functional and structural features in genomic datasets

    Directory of Open Access Journals (Sweden)

    Promponas Vasilis J

    2003-10-01

    Full Text Available Abstract Background The availability of increasing amounts of sequence data from completely sequenced genomes boosts the development of new computational methods for automated genome annotation and comparative genomics. Therefore, there is a need for tools that facilitate the visualization of raw data and results produced by bioinformatics analysis, providing new means for interactive genome exploration. Visual inspection can be used as a basis to assess the quality of various analysis algorithms and to aid in-depth genomic studies. Results GeneViTo is a JAVA-based computer application that serves as a workbench for genome-wide analysis through visual interaction. The application deals with various experimental information concerning both DNA and protein sequences (derived from public sequence databases or proprietary data sources and meta-data obtained by various prediction algorithms, classification schemes or user-defined features. Interaction with a Graphical User Interface (GUI allows easy extraction of genomic and proteomic data referring to the sequence itself, sequence features, or general structural and functional features. Emphasis is laid on the potential comparison between annotation and prediction data in order to offer a supplement to the provided information, especially in cases of "poor" annotation, or an evaluation of available predictions. Moreover, desired information can be output in high quality JPEG image files for further elaboration and scientific use. A compilation of properly formatted GeneViTo input data for demonstration is available to interested readers for two completely sequenced prokaryotes, Chlamydia trachomatis and Methanococcus jannaschii. Conclusions GeneViTo offers an inspectional view of genomic functional elements, concerning data stemming both from database annotation and analysis tools for an overall analysis of existing genomes. The application is compatible with Linux or Windows ME-2000-XP operating

  16. Phase fronts and synchronization patterns in forced oscillatory systems

    Directory of Open Access Journals (Sweden)

    Ehud Meron

    2000-01-01

    Full Text Available This is a review of recent studies of extended oscillatory systems that are subjected to periodic temporal forcing. The periodic forcing breaks the continuous time translation symmetry and leaves a discrete set of stable uniform phase states. The multiplicity of phase states allows for front structures that shift the oscillation phase by π/n where n=1,2,…, hereafter π/n-fronts. The main concern here is with front instabilities and their implications on pattern formation. Most theoretical studies have focused on the 2:1 resonance where the system oscillates at half the driving frequency. All front solutions in this case are π-fronts. At high forcing strengths only stationary fronts exist. Upon decreasing the forcing strength the stationary fronts lose stability to pairs of counter-propagating fronts. The coexistence of counter-propagating fronts allows for traveling domains and spiral waves. In the 4:1 resonance stationary π-fronts coexist with π/2-fronts. At high forcing strengths the stationary π-fronts are stable and standing two-phase waves, consisting of successive oscillatory domains whose phases differ by π,, prevail. Upon decreasing the forcing strength the stationary π-fronts lose stability and decompose into pairs of propagating π/2-fronts. The instability designates a transition from standing two-phase waves to traveling four-phase waves. Analogous decomposition instabilities have been found numerically in higher 2n:1 resonances. The available theory is used to account for a few experimental observations made on the photosensitive Belousov–Zhabotinsky reaction subjected to periodic illumination. Observations not accounted for by the theory are pointed out.

  17. PACS-based interface for 3D anatomical structure visualization and surgical planning

    Science.gov (United States)

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  18. Double-Front Detonation Waves

    Science.gov (United States)

    Gubin, S. A.; Sumskoi, S. I.; Victorov, S. B.

    According to the theory of detonation, in a detonation wave there is a sound plane, named Chapman-Jouguet (CJ) plane. There are certain stationary parameters for this plane. In this work the possibility of the second CJ plane is shown. This second CJ plane is stationary as well. The physical mechanism of non-equilibrium transition providing the existence of the second CJ plane is presented. There is a non-equilibrium state, when the heat is removed from the reaction zone and the heat capacity decreases sharply. As a result of this non-equilibrium state, the sound velocity increases, and the local supersonic zone with second sonic plane (second CJ plane) appears. So the new mode of detonation wave is predicted. Equations describing this mode of detonation are presented. The exact analytical solution for the second CJ plane parameters is obtained. The example of double-front detonation in high explosive (TNT) is presented. In this double-front structure "nanodiamond-nanographite" phase transition takes place in condensed particles of detonation products.

  19. Hierarchical structural control of visual properties in self-assembled photonic-plasmonic pigments

    CERN Document Server

    Koay, Natalie; Kay, Theresa M; Nerger, Bryan A; Miles-Rossouw, Malaika; Shirman, Tanya; Vu, Thy L; England, Grant; Phillips, Katherine R; Utech, Stefanie; Vogel, Nicolas; Kolle, Mathias; Aizenberg, Joanna

    2014-01-01

    We present a simple one-pot co-assembly method for the synthesis of hierarchically structured pigment particles consisting of silica inverse-opal bricks that are doped with plasmonic absorbers. We study the interplay between the plasmonic and photonic resonances and their effect on the visual appearance of macroscopic collections of photonic bricks that are distributed in randomized orientations. Manipulating the pore geometry tunes the wavelength- and angle-dependence of the scattering profile, which can be engineered to produce angle-dependent Bragg resonances that can either enhance or contrast with the color produced by the plasmonic absorber. By controlling the overall dimensions of the photonic bricks and their aspect ratios, their preferential alignment can either be encouraged or suppressed. This causes the Bragg resonance to appear either as uniform color travel in the former case or as sparse iridescent sparkle in the later case. By manipulating the surface chemistry of these photonic bricks, which ...

  20. The MI bundle: enabling network and structural biology in genome visualization tools.

    Science.gov (United States)

    Céol, Arnaud; Müller, Heiko

    2015-11-15

    Prioritization of candidate genes emanating from large-scale screens requires integrated analyses at the genomics, molecular, network and structural biology levels. We have extended the Integrated Genome Browser (IGB) to facilitate these tasks. The graphical user interface greatly simplifies building disease networks and zooming in at atomic resolution to identify variations in molecular complexes that may affect molecular interactions in the context of genomic data. All results are summarized in genome tracks and can be visualized and analyzed at the transcript level. The MI Bundle is a plugin for the IGB. The plugin, help, video and tutorial are available at http://cru.genomics.iit.it/igbmibundle/ and https://github.com/CRUiit/igb-mi-bundle/wiki. The source code is released under the Apache License, Version 2. arnaud.ceol@iit.it Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

  1. cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology

    Science.gov (United States)

    Johnson, Graham T.; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.

    2014-01-01

    cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of models and with recipes and models for five biological systems: blood plasma, cytoplasm, synaptic vesicles, HIV and a mycoplasma cell. We have applied cellPACK to model distributions of HIV envelope protein to test several hypotheses for consistency with experimental observations. Biologists, educators, and outreach specialists can interact with cellPACK models, develop new recipes and perform packing experiments through scripting and graphical user interfaces at http://cellPACK.org. PMID:25437435

  2. A period of structural plasticity at the axon initial segment in developing visual cortex

    Directory of Open Access Journals (Sweden)

    Annika eGutzmann

    2014-03-01

    Full Text Available Cortical networks are shaped by sensory experience and are most susceptible to modifications during critical periods characterized by enhanced plasticity at the structural and functional level. A system particularly well-studied in this context is the mammalian visual system. Plasticity has been documented for the somatodendritic compartment of neurons in detail. A neuronal microdomain not yet studied in this context is the axon initial segment (AIS located at the proximal axon segment. It is a specific electrogenic axonal domain and the site of action potential generation. Recent studies showed that structure and function of the AIS can be dynamically regulated. Here we hypothesize that the AIS shows a dynamic regulation during maturation of the visual cortex. We therefore analyzed AIS length development from embryonic day (E 12.5 to adulthood in mice. A tri-phasic time course of AIS length remodeling during development was observed. AIS first appeared at E14.5 and increased in length throughout the postnatal period to a peak between postnatal day (P 10 to P15 (eyes open P13-14. Then, AIS length was reduced significantly around the beginning of the critical period for ocular dominance plasticity (CP, P21. Shortest AIS were observed at the peak of the CP (P28, followed by a moderate elongation towards the end of the CP (P35. To test if the dynamic maturation of the AIS is influenced by eye opening (onset of activity, animals were deprived of visual input before and during the CP. Deprivation for 1 week prior to eye opening did not affect AIS length development. However, deprivation from P0-P28 and P14-P28 resulted in AIS length distribution similar to the peak at P15. In other words, deprivation from birth prevents the transient shortening of the AIS and maintains an immature AIS length. These results are the first to suggest a dynamic maturation of the AIS in cortical neurons and point to novel mechanisms in the development of neuronal

  3. GWAS in a box: statistical and visual analytics of structured associations via GenAMap.

    Science.gov (United States)

    Xing, Eric P; Curtis, Ross E; Schoenherr, Georg; Lee, Seunghak; Yin, Junming; Puniyani, Kriti; Wu, Wei; Kinnaird, Peter

    2014-01-01

    With the continuous improvement in genotyping and molecular phenotyping technology and the decreasing typing cost, it is expected that in a few years, more and more clinical studies of complex diseases will recruit thousands of individuals for pan-omic genetic association analyses. Hence, there is a great need for algorithms and software tools that could scale up to the whole omic level, integrate different omic data, leverage rich structure information, and be easily accessible to non-technical users. We present GenAMap, an interactive analytics software platform that 1) automates the execution of principled machine learning methods that detect genome- and phenome-wide associations among genotypes, gene expression data, and clinical or other macroscopic traits, and 2) provides new visualization tools specifically designed to aid in the exploration of association mapping results. Algorithmically, GenAMap is based on a new paradigm for GWAS and PheWAS analysis, termed structured association mapping, which leverages various structures in the omic data. We demonstrate the function of GenAMap via a case study of the Brem and Kruglyak yeast dataset, and then apply it on a comprehensive eQTL analysis of the NIH heterogeneous stock mice dataset and report some interesting findings. GenAMap is available from http://sailing.cs.cmu.edu/genamap.

  4. GWAS in a box: statistical and visual analytics of structured associations via GenAMap.

    Directory of Open Access Journals (Sweden)

    Eric P Xing

    Full Text Available With the continuous improvement in genotyping and molecular phenotyping technology and the decreasing typing cost, it is expected that in a few years, more and more clinical studies of complex diseases will recruit thousands of individuals for pan-omic genetic association analyses. Hence, there is a great need for algorithms and software tools that could scale up to the whole omic level, integrate different omic data, leverage rich structure information, and be easily accessible to non-technical users. We present GenAMap, an interactive analytics software platform that 1 automates the execution of principled machine learning methods that detect genome- and phenome-wide associations among genotypes, gene expression data, and clinical or other macroscopic traits, and 2 provides new visualization tools specifically designed to aid in the exploration of association mapping results. Algorithmically, GenAMap is based on a new paradigm for GWAS and PheWAS analysis, termed structured association mapping, which leverages various structures in the omic data. We demonstrate the function of GenAMap via a case study of the Brem and Kruglyak yeast dataset, and then apply it on a comprehensive eQTL analysis of the NIH heterogeneous stock mice dataset and report some interesting findings. GenAMap is available from http://sailing.cs.cmu.edu/genamap.

  5. Using the PyMOL Application to Reinforce Visual Understanding of Protein Structure

    Science.gov (United States)

    Rigsby, Rachel E.; Parker, Alison B.

    2016-01-01

    Visualization of chemical concepts can be challenging for many students. This is arguably a critical skill for beginning students of biochemistry to develop, since new information is often presented visually in the form of textbook figures. It is recommended that visual literacy be explicitly taught in the classroom rather than assuming that…

  6. Seeing the song: left auditory structures may track auditory-visual dynamic alignment.

    Directory of Open Access Journals (Sweden)

    Julia A Mossbridge

    Full Text Available Auditory and visual signals generated by a single source tend to be temporally correlated, such as the synchronous sounds of footsteps and the limb movements of a walker. Continuous tracking and comparison of the dynamics of auditory-visual streams is thus useful for the perceptual binding of information arising from a common source. Although language-related mechanisms have been implicated in the tracking of speech-related auditory-visual signals (e.g., speech sounds and lip movements, it is not well known what sensory mechanisms generally track ongoing auditory-visual synchrony for non-speech signals in a complex auditory-visual environment. To begin to address this question, we used music and visual displays that varied in the dynamics of multiple features (e.g., auditory loudness and pitch; visual luminance, color, size, motion, and organization across multiple time scales. Auditory activity (monitored using auditory steady-state responses, ASSR was selectively reduced in the left hemisphere when the music and dynamic visual displays were temporally misaligned. Importantly, ASSR was not affected when attentional engagement with the music was reduced, or when visual displays presented dynamics clearly dissimilar to the music. These results appear to suggest that left-lateralized auditory mechanisms are sensitive to auditory-visual temporal alignment, but perhaps only when the dynamics of auditory and visual streams are similar. These mechanisms may contribute to correct auditory-visual binding in a busy sensory environment.

  7. Design and Verification for Front Mirror-body Structure of On-axis Three Mirror Anastigmatic Space Camera%空间同轴三反相机前镜身结构设计与验证

    Institute of Scientific and Technical Information of China (English)

    王小勇; 郭崇岭; 胡永力

    2011-01-01

    空间同轴三反相机前镜身结构支撑相机的主、次镜,影响相机的成像性能和稳定性,是光学系统的敏感环节.针对长焦距空间同轴三反相机光学系统,为了获得刚性好、温度稳定性好的前镜身结构,本文从殷钢、碳纤维这二种低膨胀系数、高刚度的结构材料进行了优选,通过有限元分析比较,选择力学特性更好、重量更轻的碳纤维复合材料;通过力学特性和光学特性对前镜身构件三杆或四杆结构形式中进行了选择,优选了三杆结构形式;最终方案为碳纤维复合材料材薄壁筒和钛合金三支杆构成前镜身光机结构,采用遗传算法优化结合有限元分析计算对前镜身构件中的次镜连接杆结构进行了尺寸优化,使其重量减轻43%,一阶频率提高14%,热变形减小26%,满足了设计要求.通过对产品实物进行力学试验、尺寸稳定性真空稳定性试验和温度稳定性试验,测试了相机前镜身结构的各项性能,验证了前镜身结构工程设计的正确性.%The primary and secondary mirrors of on-axis three mirror anastigmatic (TMA) space camera are connected and supported by its front mirror-body structure, which affects both imaging performances and stability of the camera and is sensitive component of optical system. For better rigidity and temperature stability, front mirror-body structure chooses low expansile coefficient and high rigidity materials in long-focus on-axis TMA space camera optical system. Finite element analysis shows that carbon fiber reinforced plastics is better than Invar alloy in mechanical performance and weight lost. Three supporting rods main structure also excels four supporting rods in mechanical and optical characters. The carbon fiber reinforced plastics (CFRP) thin-walled cylinder and titanium alloy supporting rod are used for the front mirror-body opto-mechanical structure of the long-focus on-axis TMA space camera optical system

  8. New Front End Technology

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, D; Jovanovic, I; Comaskey, B J

    2001-02-01

    The next generation of Petawatt class lasers will require the development of new laser technology. Optical parametric chirped pulse amplification (OPCPA) holds a potential to increase the peak power level to >10 PW with existing grating technology through ultrashort pulses. Furthermore, by utilizing a new type of front-end system based on optical parametric amplification, pulses can be produced with substantially higher contrast than with Ti:sapphire regenerative amplifier technology. We performed extensive study of OPCPA using a single crystal-based OPA. We developed a replacement for Ti:sapphire regenerative amplifier for high peak power lasers based on OPCPA, with an output of 30 mJ, at 10 Hz repetition rate and 16.5 nm spectral bandwidth. We developed a 3D numerical model for OPCPA and we performed a theoretical study of influences of pump laser beam quality on optical parametric amplification. Our results indicate that OPCPA represents a valid replacement for Ti:sapphire in the front end of high energy short pulse lasers.

  9. Progress in front propagation research

    Science.gov (United States)

    Fort, Joaquim; Pujol, Toni

    2008-08-01

    We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and cross-disciplinary applications, including reduced-variable models of combustion flames, Reid's paradox of rapid forest range expansions, the European colonization of North America during the 19th century, the Neolithic transition in Europe from 13 000 to 5000 years ago, the description of subsistence boundaries, the formation of cultural boundaries, the spread of genetic mutations, theory and experiments on virus infections, models of cancer tumors, etc. Recent theoretical advances are unified in a single framework, encompassing very diverse systems such as those with biased random walks, distributed delays, sequential reaction and dispersion, cohabitation models, age structure and systems with several interacting species. Directions for future progress are outlined.

  10. Order Parameter Equations for Front Transitions Planar and Circular Fronts

    CERN Document Server

    Hagberg, A; Rubinstein, I; Zaltzman, B; Hagberg, Aric; Meron, Ehud

    1997-01-01

    Near a parity breaking front bifurcation, small perturbations may reverse the propagation direction of fronts. Often this results in nonsteady asymptotic motion such as breathing and domain breakup. Exploiting the time scale differences of an activator-inhibitor model and the proximity to the front bifurcation, we derive equations of motion for planar and circular fronts. The equations involve a translational degree of freedom and an order parameter describing transitions between left and right propagating fronts. Perturbations, such as a space dependent advective field or uniform curvature (axisymmetric spots), couple these two degrees of freedom. In both cases this leads to a transition from stationary to oscillating fronts as the parity breaking bifurcation is approached. For axisymmetric spots, two additional dynamic behaviors are found: rebound and collapse.

  11. From the front

    Energy Technology Data Exchange (ETDEWEB)

    Price, Stephen [Los Alamos National Laboratory

    2009-01-01

    The causes of recent dynamic thinning of Greenland's outlet glaciers have been debated. Realistic simulations suggest that changes at the marine fronts of these glaciers are to blame, implying that dynamic thinning will cease once the glaciers retreat to higher ground. For the last decade, many outlet glaciers in Greenland that terminate in the ocean have accelerated, thinned, and retreated. To explain these dynamic changes, two hypotheses have been discussed. Atmospheric warming has increased surface melting and may also have increased the amount of meltwater reaching the glacier bed, increasing lubrication at the base and hence the rate of glacier sliding. Alternatively, a change in the delicate balance of forces where the glacier fronts meet the ocean could trigger the changes. Faezeh Nick and colleagues5 present ice-sheet modeling experiments that mimic the observations on Helheim glacier, East Greenland, and suggest that the dynamic behaviour of outlet glaciers follows from perturbations at their marine fronts. Greenland's ice sheet loses mass partly through surface melting and partly through fast flowing outlet glaciers that connect the vast plateau of inland ice with the ocean. Earlier ice sheet models have failed to reproduce the dynamic variability exhibited by ice sheets over time. It has therefore not been possible to distinguish with confidence between basal lubrication from surface meltwater and changes at the glaciers' marine fronts as causes for the observed changes on Greenland's outlet glaciers. But this distinction bears directly on future sea-level rise, the raison d'etre of much of modern-day glaciology: If the recent dynamic mass loss Greenland's outlet glaciers is linked to changing atmospheric temperatures, it may continue for as long as temperatures continue to increase. On the other hand, if the source of the dynamic mass loss is a perturbation at the ice-ocean boundary, these glaciers will lose contact with

  12. Understanding ill-structured engineering ethics problems through a collaborative learning and argument visualization approach.

    Science.gov (United States)

    Hoffmann, Michael; Borenstein, Jason

    2014-03-01

    As a committee of the National Academy of Engineering recognized, ethics education should foster the ability of students to analyze complex decision situations and ill-structured problems. Building on the NAE's insights, we report about an innovative teaching approach that has two main features: first, it places the emphasis on deliberation and on self-directed, problem-based learning in small groups of students; and second, it focuses on understanding ill-structured problems. The first innovation is motivated by an abundance of scholarly research that supports the value of deliberative learning practices. The second results from a critique of the traditional case-study approach in engineering ethics. A key problem with standard cases is that they are usually described in such a fashion that renders the ethical problem as being too obvious and simplistic. The practitioner, by contrast, may face problems that are ill-structured. In the collaborative learning environment described here, groups of students use interactive and web-based argument visualization software called "AGORA-net: Participate - Deliberate!". The function of the software is to structure communication and problem solving in small groups. Students are confronted with the task of identifying possible stakeholder positions and reconstructing their legitimacy by constructing justifications for these positions in the form of graphically represented argument maps. The argument maps are then presented in class so that these stakeholder positions and their respective justifications become visible and can be brought into a reasoned dialogue. Argument mapping provides an opportunity for students to collaborate in teams and to develop critical thinking and argumentation skills.

  13. Visualizing the Structure of the Earth’s Lithosphere on the Google Earth Virtual-Globe Platform

    Directory of Open Access Journals (Sweden)

    Liangfeng Zhu

    2016-03-01

    Full Text Available While many of the current methods for representing the existing global lithospheric models are suitable for academic investigators to conduct professional geological and geophysical research, they are not suited to visualize and disseminate the lithospheric information to non-geological users (such as atmospheric scientists, educators, policy-makers, and even the general public as they rely on dedicated computer programs or systems to read and work with the models. This shortcoming has become more obvious as more and more people from both academic and non-academic institutions struggle to understand the structure and composition of the Earth’s lithosphere. Google Earth and the concomitant Keyhole Markup Language (KML provide a universal and user-friendly platform to represent, disseminate, and visualize the existing lithospheric models. We present a systematic framework to visualize and disseminate the structure of the Earth’s lithosphere on Google Earth. A KML generator is developed to convert lithospheric information derived from the global lithospheric model LITHO1.0 into KML-formatted models, and a web application is deployed to disseminate and visualize those models on the Internet. The presented framework and associated implementations can be easily exported for application to support interactively integrating and visualizing the internal structure of the Earth with a global perspective.

  14. Head/tail Breaks for Visualization of City Structure and Dynamics

    CERN Document Server

    Jiang, Bin

    2015-01-01

    The things surrounding us vary dramatically, which implies that there are far more small things than large ones, e.g., far more small cities than large ones in the world. This dramatic variation is often referred to as fractal or scaling. To better reveal the fractal or scaling structure, a new classification scheme, namely head/tail breaks, has been developed to recursively derive different classes or hierarchical levels. The head/tail breaks works as such: divide things into a few large ones in the head (those above the average) and many small ones (those below the average) in the tail, and recursively continue the dividing process for the large ones (or the head) until the notion of far more small things than large ones has been violated. This paper attempts to argue that head/tail breaks can be a powerful visualization tool for illustrating structure and dynamics of natural cities. Natural cities refer to naturally or objectively defined human settlements based on a meaningful cutoff averaged from a massi...

  15. Visualizing Distributions from Multi-Return Lidar Data to Understand Forest Structure

    Science.gov (United States)

    Kao, David L.; Kramer, Marc; Luo, Alison; Dungan, Jennifer; Pang, Alex

    2004-01-01

    Spatially distributed probability density functions (pdfs) are becoming relevant to the Earth scientists and ecologists because of stochastic models and new sensors that provide numerous realizations or data points per unit area. One source of these data is from multi-return airborne lidar, a type of laser that records multiple returns for each pulse of light sent towards the ground. Data from multi-return lidar is a vital tool in helping us understand the structure of forest canopies over large extents. This paper presents several new visualization tools that allow scientists to rapidly explore, interpret and discover characteristic distributions within the entire spatial field. The major contribution from-this work is a paradigm shift which allows ecologists to think of and analyze their data in terms of the distribution. This provides a way to reveal information on the modality and shape of the distribution previously not possible. The tools allow the scientists to depart from traditional parametric statistical analyses and to associate multimodal distribution characteristics to forest structures. Examples are given using data from High Island, southeast Alaska.

  16. Spatial Visualization Tasks To Support Students’ Spatial Structuring In Learning Volume Measurement

    Directory of Open Access Journals (Sweden)

    Shintia Revina

    2011-07-01

    Full Text Available Many prior researches found that most of students in grade five tendedto have difficulty in fully grasping the concept of volume measurementbecause they have to build their competence in spatial structuring. The unit of volume “packing” measurement must be integrated andcoordinated in three-dimension. On the other hand, it is revealed theerrors that students made on the volume measurement tasks with threedimensional cube arrays are related to some aspects of spatialvisualization, such as the skill to "read off" two-dimensionalrepresentation of solid objects. For those reasons, this research is aimed to develop classroom activities with the use of spatial visualization tasks to support students’ spatial structuring in learning volume measurement. Consequently, design research was chosen as an appropriate means to achieve this research goal. In this research, a sequence of instructional activities is designed and developed based on the hypothesis of students’ learning processes. This research was conducted in grade 5 of SD Pupuk Sriwijaya Palembang, Indonesia

  17. CALCMIN - an EXCEL™ Visual Basic application for calculating mineral structural formulae from electron microprobe analyses

    Science.gov (United States)

    Brandelik, Andreas

    2009-07-01

    CALCMIN, an open source Visual Basic program, was implemented in EXCEL™. The program was primarily developed to support geoscientists in their routine task of calculating structural formulae of minerals on the basis of chemical analysis mainly obtained by electron microprobe (EMP) techniques. Calculation programs for various minerals are already included in the form of sub-routines. These routines are arranged in separate modules containing a minimum of code. The architecture of CALCMIN allows the user to easily develop new calculation routines or modify existing routines with little knowledge of programming techniques. By means of a simple mouse-click, the program automatically generates a rudimentary framework of code using the object model of the Visual Basic Editor (VBE). Within this framework simple commands and functions, which are provided by the program, can be used, for example, to perform various normalization procedures or to output the results of the computations. For the clarity of the code, element symbols are used as variables initialized by the program automatically. CALCMIN does not set any boundaries in complexity of the code used, resulting in a wide range of possible applications. Thus, matrix and optimization methods can be included, for instance, to determine end member contents for subsequent thermodynamic calculations. Diverse input procedures are provided, such as the automated read-in of output files created by the EMP. Furthermore, a subsequent filter routine enables the user to extract specific analyses in order to use them for a corresponding calculation routine. An event-driven, interactive operating mode was selected for easy application of the program. CALCMIN leads the user from the beginning to the end of the calculation process.

  18. Novel Perspectives from Light-Front QCD, Super-Conformal Algebra, and Light-Front Holography

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    Light-Front Quantization – Dirac’s “Front Form” – provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic LFWFs. One obtains new insights into the hadronic mass scale, the hadronic spectrum, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons. I also discuss evidence that the antishadowing of nuclear structure functions is nonuniversal; i.e., flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with the momentum and other sum rules for the nuclear parton distribution functions.

  19. Refraction and reflection of diffusion fronts.

    Science.gov (United States)

    Remhof, A; Wijngaarden, R J; Griessen, R

    2003-04-11

    Diffusion waves form the basis of several measurement technologies in materials science as well as in biological systems. They are, however, so heavily damped that their observation is a real challenge to the experimentalist. We show that accurate information about the refraction-like and reflection-like behavior of diffusion waves can be obtained by studying diffusion fronts. For this we use hydrogen in a metal as a model system and visualize its 2D migration with an optical indicator. The similarities between classical optics and diffusion, in particular, the applicability of Snell's law to diffusive systems are discussed. Our measurements are in good agreement with numerical simulations.

  20. Representation of Gravity-Aligned Scene Structure in Ventral Pathway Visual Cortex.

    Science.gov (United States)

    Vaziri, Siavash; Connor, Charles E

    2016-03-21

    The ventral visual pathway in humans and non-human primates is known to represent object information, including shape and identity [1]. Here, we show the ventral pathway also represents scene structure aligned with the gravitational reference frame in which objects move and interact. We analyzed shape tuning of recently described macaque monkey ventral pathway neurons that prefer scene-like stimuli to objects [2]. Individual neurons did not respond to a single shape class, but to a variety of scene elements that are typically aligned with gravity: large planes in the orientation range of ground surfaces under natural viewing conditions, planes in the orientation range of ceilings, and extended convex and concave edges in the orientation range of wall/floor/ceiling junctions. For a given neuron, these elements tended to share a common alignment in eye-centered coordinates. Thus, each neuron integrated information about multiple gravity-aligned structures as they would be seen from a specific eye and head orientation. This eclectic coding strategy provides only ambiguous information about individual structures but explicit information about the environmental reference frame and the orientation of gravity in egocentric coordinates. In the ventral pathway, this could support perceiving and/or predicting physical events involving objects subject to gravity, recognizing object attributes like animacy based on movement not caused by gravity, and/or stabilizing perception of the world against changes in head orientation [3-5]. Our results, like the recent discovery of object weight representation [6], imply that the ventral pathway is involved not just in recognition, but also in physical understanding of objects and scenes.

  1. Biological Activity at Oceanic Fronts.

    Science.gov (United States)

    1985-12-01

    and/or phytoplankton concentrations between the adjacent areas. High particle concentrations are associated with a front east of the Galapagos Islands...yeTlowfin, albacore, and bluefin tunas, mackerel, salmon, and some whales (Uda, 1938, 1952,. 9.=, 1973; Uda and Ishino, 1958). Behavioral responses of...Marine mammals ,Gaskin, 1976) also utilize tidal fronts. Minke whales were observed to feed on herring or capelin collected in fronts and fin whales fed

  2. Structural asymmetry of cortical visual areas is related to ocular dominance

    DEFF Research Database (Denmark)

    Jensen, Bettina H; Hougaard, Anders; Amin, Faisal M

    2015-01-01

    The grey matter of the human brain is asymmetrically distributed between the cerebral hemispheres. This asymmetry includes visual areas, but its relevance to visual function is not understood. Voxel-based morphometry is a well-established technique for localization and quantification of cerebral...... grey matter on the basis of MR images. This method has been used previously for interhemispheric comparison, but without examining the functional implications of the identified anatomical asymmetries of the visual system. The aim of the present study was to relate anatomical interhemispheric...... asymmetries to asymmetries of visual function. We examined grey matter asymmetries of visual areas in a large population (n=56) of ophthalmologically and neurologically healthy individuals. We used state-of-the-art 3 T MRI and voxel-based morphometry to relate the visual parameters, (a) ocular dominance, (b...

  3. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia

    NARCIS (Netherlands)

    Langen, C.D.; White, T.; Ikram, M.A.; Vernooij, M.W.; Niessen, W.J.

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significan

  4. Google Earth Mapping Exercises for Structural Geology Students--A Promising Intervention for Improving Penetrative Visualization Ability

    Science.gov (United States)

    Giorgis, Scott

    2015-01-01

    Three-dimensional thinking skills are extremely useful for geoscientists, and at the undergraduate level, these skills are often emphasized in structural geology courses. Google Earth is a powerful tool for visualizing the three-dimensional nature of data collected on the surface of Earth. The results of a 5 y pre- and posttest study of the…

  5. Google Earth Mapping Exercises for Structural Geology Students--A Promising Intervention for Improving Penetrative Visualization Ability

    Science.gov (United States)

    Giorgis, Scott

    2015-01-01

    Three-dimensional thinking skills are extremely useful for geoscientists, and at the undergraduate level, these skills are often emphasized in structural geology courses. Google Earth is a powerful tool for visualizing the three-dimensional nature of data collected on the surface of Earth. The results of a 5 y pre- and posttest study of the…

  6. Visualizing the internal structure of subaqueous, high-concentration sediment-laden flows: implication of rheology to flow structure

    Science.gov (United States)

    Perillo, M. M.; Buttles, J.; Mohrig, D. C.; Kane, I.; Pontén, A.; Brown, D.; Minton, B. W.

    2013-12-01

    Subaqueous sediment-laden flows are thought to be the main mechanism transporting sediments to the deep sea. Understanding the processes governing these flows is crucial to building predictive models of flow behaviour, sediment transport and deposition and is applicable to a wide range of disciplines. Physical modelling using a wide range of experimental facilities and measurement techniques has significantly advanced our understanding of these sediment-laden flows and their ability to erode, transport and deposit sediments. However, for the case of high-sediment concentration flows, measuring flow and depositional properties is still a challenge. Here, we present results from an acoustic reflection technique that allows for direct and noninvasive visualization of the internal structure of high concentration, clay-rich, sand-laden flows with a range of initial yield strengths (0-26 Pa). As the acoustic signal travels through the sediment-laden flow, it encounters zones of varying acoustic impedance that are due to temporal and spatial changes in sediment concentration, grain size and sorting, and flow mixing. The reflected signal is processed and interpreted using seismic techniques developed in exploration geophysics. The ultrasonic reflection data captured two distinct flow stages, an active stage and a post-depositional creeping stage. The clay-rich sand-laden flows showed stratification expressed by three clear vertical zones: (a) an upper relatively dilute turbulent zone, (b) a zone with high sediment concentration and significantly reduced mixing and (c) an aggrading bed of static grains.

  7. Photoionization effects in ionization fronts

    Energy Technology Data Exchange (ETDEWEB)

    Arrayas, Manuel [Departamento de Electromagnetismo, Universidad Rey Juan Carlos, Tulipan s/n, 28933 Mostoles, Madrid (Spain); Fontelos, Marco A [Departamento de Matematicas, Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, C/Serrano 123, 28006 Madrid (Spain); Trueba, Jose L [Departamento de Electromagnetismo, Universidad Rey Juan Carlos, Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2006-12-21

    In this paper we study the effects of photoionization processes on the propagation of both negative and positive ionization fronts in streamer discharge. We show that negative fronts accelerate in the presence of photoionization events. The appearance and propagation of positive ionization fronts travelling with constant velocity is explained as the result of the combined effects of photoionization and electron diffusion. The photoionization range plays an important role in the selection of the velocity of the ionization front as we show in this work.

  8. PanViz: interactive visualization of the structure of functionally annotated pangenomes

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David

    2017-01-01

    with gene ontology based navigation of gene groups. Furthermore it allows for rich and complex visual querying of gene groups in the pangenome. PanViz visualizations require no external programs and are easily sharable, allowing for rapid pangenome analyses. PanViz is written entirely in Java......PanViz is a novel, interactive, visualization tool for pangenome analysis. PanViz allows visualization of changes in gene group (groups of similar genes across genomes) classification as different subsets of pangenomes are selected, as well as comparisons of individual genomes to pangenomes...

  9. PanViz: interactive visualization of the structure of functionally annotated pangenomes.

    Science.gov (United States)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David; Månsson, Maria

    2017-01-05

    PanViz is a novel, interactive, visualization tool for pangenome analysis. PanViz allows visualization of changes in gene group (groups of similar genes across genomes) classification as different subsets of pangenomes are selected, as well as comparisons of individual genomes to pangenomes with gene ontology based navigation of gene groups. Furthermore it allows for rich and complex visual querying of gene groups in the pangenome. PanViz visualizations require no external programs and are easily sharable, allowing for rapid pangenome analyses.

  10. Impact of retinopathy of prematurity on ocular structures and visual functions.

    Science.gov (United States)

    Fielder, Alistair; Blencowe, Hannah; O'Connor, Anna; Gilbert, Clare

    2015-03-01

    The preterm baby may develop ophthalmic sequelae which can be due to prematurity per se, due to retinopathy of prematurity (ROP) or due to neurological damage. Focusing on the former two, we discuss how in high-income countries the risk of sight-threatening ROP is largely confined to babies visual impairment. We discuss sequelae and how they affect the eye and its shape, strabismus and finally consider their impact on visual functions, including visual acuity, the visual field, colour vision and contrast sensitivity.

  11. QCD Phenomenology and Light-Front Wavefunctions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2001-11-21

    A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions.

  12. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Carolyn D Langen

    Full Text Available Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1 middle-aged versus elderly subjects; and (2 patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only

  13. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

    Science.gov (United States)

    Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy

  14. An uncertainty principle underlying the pinwheel structure in the primary visual cortex

    CERN Document Server

    Barbieri, Davide; Sanguinetti, Gonzalo; Sarti, Alessandro

    2010-01-01

    The visual information in V1 is processed by an array of modules called orientation preference columns. In some species including humans, orientation columns are radially arranged around singular points like the spokes of a wheel, that are called pinwheels. The pinwheel structure has been observed first with optical imaging techniques and more recently by in vivo two-photon imaging proving their organization with single cell precision. In this research we provide evidence that pinwheels are de facto optimal distributions for coding at the best angular position and momentum. In the last years many authors have recognized that the functional architecture of V1 is locally invariant with respect to the symmetry group of rotations and translations SE(2). In the present study we show that the orientation cortical maps used to construct pinwheels can be modeled as coherent states, i.e. the configurations best localized both in angular position and angular momentum. The theory we adopt is based on the well known unce...

  15. Quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding

    Science.gov (United States)

    Parsons, D. R.; Simmons, S.; Best, J.

    2010-12-01

    Multibeam Echo-Sounder systems have developed rapidly over recent decades and are routinely deployed to provide high-resolution bathymetric details in range of aquatic environments. Modern data handling and storage technologies now facilitate the logging of the raw acoustic back-scatter information that was previously discarded by these systems. This paper describes methodologies that exploit this logging capability to quantify the concentration and dynamics of suspended sediment within the water column and presents a novel method that also allows for quantification of 2D flow velocities. This development provides a multi-purpose tool for the holistic surveying of the process linkages between flow, sediment transport and bed morphology. The application of this new technique is illustrated with reference to flow over alluvial sand dunes, which allows, for the first time in a field study, quantitative visualization of larg-scale, whole flow field, turbulent coherent flow structures, associated with the dune leeside, that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows. CFS captured by MBES in the lee of an alluvial dune. Contours of suspended sediment concentration and superimposed 2D flow velocity vectors

  16. The architecture of visual narrative comprehension: the interaction of narrative structure and page layout in understanding comics.

    Science.gov (United States)

    Cohn, Neil

    2014-01-01

    How do people make sense of the sequential images in visual narratives like comics? A growing literature of recent research has suggested that this comprehension involves the interaction of multiple systems: The creation of meaning across sequential images relies on a "narrative grammar" that packages conceptual information into categorical roles organized in hierarchic constituents. These images are encapsulated into panels arranged in the layout of a physical page. Finally, how panels frame information can impact both the narrative structure and page layout. Altogether, these systems operate in parallel to construct the Gestalt whole of comprehension of this visual language found in comics.

  17. Influence of coral cover and structural complexity on the accuracy of visual surveys of coral-reef fish communities

    KAUST Repository

    Coker, D. J.

    2017-04-20

    Using manipulated patch reefs with combinations of varying live-coral cover (low, medium and high) and structural complexity (low and high), common community metrics (abundance, diversity, richness and community composition) collected through standard underwater visual census techniques were compared with exhaustive collections using a fish anaesthetic (clove oil). This study showed that reef condition did not influence underwater visual census estimates at a community level, but reef condition can influence the detectability of some small and cryptic species and this may be exacerbated if surveys are conducted on a larger scale.

  18. The architecture of visual narrative comprehension: The interaction of narrative structure and page layout in understanding comics

    Directory of Open Access Journals (Sweden)

    Neil eCohn

    2014-07-01

    Full Text Available How do people make sense of the sequential images in visual narratives like comics? A growing literature of recent research has suggested that this comprehension involves the interaction of multiple systems: The creation of meaning across sequential images relies on a narrative grammar that packages conceptual information into categorical roles organized in hierarchic constituents. These images units are encapsulated into panels arranged in the layout of a physical page. Finally, how panels frame information can impact both the narrative structure and page layout. Altogether, these systems operate in parallel to construct the gestalt whole of comprehension of this visual language found in comics.

  19. Scene statistics: neural representation of real-world structure in rapid visual perception

    NARCIS (Netherlands)

    Groen, I.I.A.

    2014-01-01

    How does the brain represent our visual environment? Research has revealed brain areas that respond to specific information such as faces and objects, but how a representation of an entire visual scene is formed is still unclear. This thesis explores the idea that scene statistics play an important

  20. Fronts and Prospects on Scientific Collaboration Between the Two Sides of the Straits: Visualization Coauthor of Advantage Disciplines%海峡两岸科学合作的前沿与前景两岸优势学科合作论文的可视化分析

    Institute of Scientific and Technical Information of China (English)

    刘则渊; 滕立; 朱晓宇

    2012-01-01

    Cooperation and synergy development in science between the Mainland and Taiwan is an important component that belongs to collaboration and development of both sides of Taiwan Straits. From JD Bernard' s science of sciences view about science collaboration, this paper took scientrometrics and knowledge visualization methods as tools to analyze scientific articles represented scientific collaboration of both Sides and enrolled by SCI for detecting scientific cooperation trends and research fronts. The results have shown that the number of collaborated articles was increasing with total papers of each Side growing in nearly 20 years and these literatures related to wide range fields but their distribution was uneven: 41.62% of them was dis- tributed in Physics, Mathmatics and Material Sciences, which are the developing quickly and relative advantaged disciplines of both Sides. Three cooperation patterns can be summarized in the three disciplines using co-citation knowledge mapping created by advanced visualization technique called Citespace: in Physics, the pattern is named single key point following the fronts with the help of third party while in Mathmatics, it can be called multi-key points to exploring fronts based on common ad- vantage of both Sides and in Material Sciences, it can be characterized as detecting fronts dispersedly through complementing each other's advantages. The future of scientific cooperation between both Sides also has been looked into distance and several proposals have been suggested: the fronts of scientific collaboration between both Sides should be expanded into synergy innovation of the both Sides, the industy-technology-research-development alliance made of joint ventures should be established in order to develop industrial technologies for civil use and joint industries, universities and institutions together. Such alliance also should be developed a cyber-enabled discovery-innovation system under network environment.%海

  1. Discrete approximations of detonation flows with structured detonation reaction zones by discontinuous front models: A program burn algorithm based on detonation shock dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bdzil, J.B. [Los Alamos National Lab., NM (United States); Jackson, T.L. [Univ. of Illinois, Urbana, IL (United States). Center for Simulation of Advanced Rockets; Stewart, D.S. [Univ. of Illinois, Urbana, IL (United States). Theoretical and Applied Mechanics

    1999-02-02

    In the design of explosive systems the generic problem that one must consider is the propagation of a well-developed detonation wave sweeping through an explosive charge with a complex shape. At a given instant of time the lead detonation shock is a surface that occupies a region of the explosive and has a dimension that is characteristic of the explosive device, typically on the scale of meters. The detonation shock is powered by a detonation reaction zone, sitting immediately behind the shock, which is on the scale of 1 millimeter or less. Thus, the ratio of the reaction zone thickness to the device dimension is of the order of 1/1,000 or less. This scale disparity can lead to great difficulties in computing three-dimensional detonation dynamics. An attack on the dilemma for the computation of detonation systems has lead to the invention of sub-scale models for a propagating detonation front that they refer to herein as program burn models. The program burn model seeks not to resolve the fine scale of the reaction zone in the sense of a DNS simulation. The goal of a program burn simulation is to resolve the hydrodynamics in the inert product gases on a grid much coarser than that required to resolve a physical reaction zone. The authors first show that traditional program burn algorithms for detonation hydrocodes used for explosive design are inconsistent and yield incorrect shock dynamic behavior. To overcome these inconsistencies, they are developing a new class of program burn models based on detonation shock dynamic (DSD) theory. It is hoped that this new class will yield a consistent and robust algorithm which reflects the correct shock dynamic behavior.

  2. Active learning of Pareto fronts.

    Science.gov (United States)

    Campigotto, Paolo; Passerini, Andrea; Battiti, Roberto

    2014-03-01

    This paper introduces the active learning of Pareto fronts (ALP) algorithm, a novel approach to recover the Pareto front of a multiobjective optimization problem. ALP casts the identification of the Pareto front into a supervised machine learning task. This approach enables an analytical model of the Pareto front to be built. The computational effort in generating the supervised information is reduced by an active learning strategy. In particular, the model is learned from a set of informative training objective vectors. The training objective vectors are approximated Pareto-optimal vectors obtained by solving different scalarized problem instances. The experimental results show that ALP achieves an accurate Pareto front approximation with a lower computational effort than state-of-the-art estimation of distribution algorithms and widely known genetic techniques.

  3. Light Front Boson Model Propagation

    Institute of Scientific and Technical Information of China (English)

    Jorge Henrique Sales; Alfredo Takashi Suzuki

    2011-01-01

    stract The scope and aim of this work is to describe the two-body interaction mediated by a particle (either the scalar or the gauge boson) within the light-front formulation. To do this, first of all we point out the importance of propagators and Green functions in Quantum Mechanics. Then we project the covariant quantum propagator onto the light front time to get the propagator for scalar particles in these coordinates. This operator propagates the wave function from x+ = 0 to x+ > O. It corresponds to the definition of the time ordering operation in the light front time x+. We calculate the light-front Green's function for 2 interacting bosons propagating forward in x+. We also show how to write down the light front Green's function from the Feynman propagator and finally make a generalization to N bosons.

  4. New Results in Light-Front Phenomenology

    CERN Document Server

    Brodsky, S J

    2004-01-01

    The light-front quantization of gauge theories such as QCD in light-cone gauge provides a frame-independent wavefunction representation of relativistic bound states, simple forms for current matrix elements, explicit unitarity, and a trivial vacuum. The freedom to choose the light-like quantization four-vector provides an explicitly covariant formulation of light-front quantization and can be used to determine the analytic structure of light-front wave functions and to define a kinematical definition of angular momentum. The AdS/CFT correspondence of large $N_C$ supergravity theory in higher-dimensional anti-de Sitter space with supersymmetric QCD in 4-dimensional space-time has interesting implications for hadron phenomenology in the conformal limit, including an all-orders demonstration of counting rules for exclusive processes. String/gauge duality also predicts the QCD power-law behavior of light-front Fock-state hadronic wavefunctions with arbitrary orbital angular momentum at high momentum transfer. The...

  5. Mapping the structure of perceptual and visual-motor abilities in healthy young adults.

    Science.gov (United States)

    Wang, Lingling; Krasich, Kristina; Bel-Bahar, Tarik; Hughes, Lauren; Mitroff, Stephen R; Appelbaum, L Gregory

    2015-05-01

    The ability to quickly detect and respond to visual stimuli in the environment is critical to many human activities. While such perceptual and visual-motor skills are important in a myriad of contexts, considerable variability exists between individuals in these abilities. To better understand the sources of this variability, we assessed perceptual and visual-motor skills in a large sample of 230 healthy individuals via the Nike SPARQ Sensory Station, and compared variability in their behavioral performance to demographic, state, sleep and consumption characteristics. Dimension reduction and regression analyses indicated three underlying factors: Visual-Motor Control, Visual Sensitivity, and Eye Quickness, which accounted for roughly half of the overall population variance in performance on this battery. Inter-individual variability in Visual-Motor Control was correlated with gender and circadian patters such that performance on this factor was better for males and for those who had been awake for a longer period of time before assessment. The current findings indicate that abilities involving coordinated hand movements in response to stimuli are subject to greater individual variability, while visual sensitivity and occulomotor control are largely stable across individuals.

  6. Coherent structure in the turbulent wake behind a circular cylinder 3. Flow visualization and hot wire measurements

    Science.gov (United States)

    Yamane, Ryuichiro; Oshima, Shuzo; Okubo, Masaaki; Kotani, Juzo

    1988-07-01

    In the previous papers the authors have reported that the two-dimensional Kármán vortices behind a circular cylinder are deformed until they form chains of spoon-shaped vortex couples whose spanwise scale is about 8 d, which is a new type of coherent structure. In this report experimental evidence of this structure is presented. Formation process of the structure and the turbulence in it were investigated for the wake behind a circular cylinder with Re = 2100 and 4200 by means of the flow visualization technique, simultaneous hot wire measurements, spanwise correlation measurements, construction of instantaneous velocity field by the conditional sampling method, etc.

  7. Application of Digital Master Tooling in Large Aircraft Front Fuselage Structure Section Prototype%数字标工在大客前机身结构部段样件试制中的应用

    Institute of Scientific and Technical Information of China (English)

    刘春锋; 郑堂介; 廖建华; 汪建东

    2013-01-01

    The idea of digital master tooling, with character and usage of physical master tooling, in air-craft manufacture for assembly coordination is presented. By means of applying it in the fabrication of large aircraft front fuselage structure section prototype, selection and application of digital master tooling are described at length based on MBD environment.%提出了在飞机制造中采用具有实物标工特征及用法的数字标工进行装配协调的方法,并在大客前机身结构部段样件的制造中进行了应用研究,阐述了在三维MBD数模环境下,进行数字标工项目选取及应用的具体工艺方法。

  8. Design of Laboratory Experiments to Study Photoionization Fronts

    Science.gov (United States)

    Gray, William James; Davis, Josh; Drake, R. Paul

    2017-06-01

    Here we present the theoretical foundation for a laboratory experiment to study photoionization fronts. Photoionization fronts play important roles in the formation and evolution of structure in the Universe. A properly designed experiment will have to control the recombination rate, electron impact ionization rate, and the initial thermal spectrum. We show that such an experiment can be designed, but requires the use of the largest high-energy-density laser facilities, such as Omega, Z, and NIF. We also show that prior experiments do not actually generate photoionization fronts, rather a heat front is produced by heat conductions. We show some initial simulation results of the current experimental design and characterize the ionization front.

  9. Visualization and Transparentization of the Structure and Stress Field of Aggregated Geomaterials Through 3D Printing and Photoelastic Techniques

    Science.gov (United States)

    Ju, Yang; Wang, Li; Xie, Heping; Ma, Guowei; Zheng, Zemin; Mao, Lingtao

    2017-06-01

    Natural resource reservoirs usually consist of heterogeneous aggregated geomaterials containing a large number of randomly distributed particles with irregular geometry. As a result, the accurate characterization of the stress field, which essentially governs the mechanical behaviour of such geomaterials, through analytical and experimental methods, is considerably difficult. Physical visualization of the stress field is a promising method to quantitatively characterize and reveal the evolution and distribution of stress in aggregated geomaterials subjected to excavation loads. This paper presents a novel integration of X-ray computed tomography (CT) imaging, three-dimensional (3D) printing, and photoelastic testing for the transparentization and visualization of the aggregated structure and stress field of heterogeneous geomaterials. In this study, a glutenite rock sample was analysed by CT to acquire the 3D aggregate structure, following which 3D printing was adopted to produce transparent models with the same aggregate structure as that of the glutenite sample. Uniaxial compression tests incorporated with photoelastic techniques were performed on the transparent models to acquire and visualize the stress distribution of the aggregated models at various loading stages. The effect of randomly distributed aggregates on the stress field characteristics of the models, occurrence of plastic zones, and fracture initiation was analysed. The stress field characteristics of the aggregated models were analysed using the finite element method (FEM). The failure process was simulated using the distinct element method (DEM). Both FEM and DEM results were compared with the experimental observations. The results showed that the proposed method can very well visualize the stress field of aggregated solids during uniaxial loading. The results of the visualization tests were in good agreement with those of the numerical simulations.

  10. Visualizing the knowledge structure and evolution of big data research in healthcare informatics.

    Science.gov (United States)

    Gu, Dongxiao; Li, Jingjing; Li, Xingguo; Liang, Changyong

    2017-02-01

    In recent years, the literature associated with healthcare big data has grown rapidly, but few studies have used bibliometrics and a visualization approach to conduct deep mining and reveal a panorama of the healthcare big data field. To explore the foundational knowledge and research hotspots of big data research in the field of healthcare informatics, this study conducted a series of bibliometric analyses on the related literature, including papers' production trends in the field and the trend of each paper's co-author number, the distribution of core institutions and countries, the core literature distribution, the related information of prolific authors and innovation paths in the field, a keyword co-occurrence analysis, and research hotspots and trends for the future. By conducting a literature content analysis and structure analysis, we found the following: (a) In the early stage, researchers from the United States, the People's Republic of China, the United Kingdom, and Germany made the most contributions to the literature associated with healthcare big data research and the innovation path in this field. (b) The innovation path in healthcare big data consists of three stages: the disease early detection, diagnosis, treatment, and prognosis phase, the life and health promotion phase, and the nursing phase. (c) Research hotspots are mainly concentrated in three dimensions: the disease dimension (e.g., epidemiology, breast cancer, obesity, and diabetes), the technical dimension (e.g., data mining and machine learning), and the health service dimension (e.g., customized service and elderly nursing). This study will provide scholars in the healthcare informatics community with panoramic knowledge of healthcare big data research, as well as research hotspots and future research directions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Visualization of phase evolution in model organic photovoltaic structures via energy-filtered transmission electron microscopy.

    Science.gov (United States)

    Herzing, Andrew A; Ro, Hyun Wook; Soles, Christopher L; DeLongchamp, Dean M

    2013-09-24

    The morphology of the active layer in an organic photovoltaic bulk-heterojunction device is controlled by the extent and nature of phase separation during processing. We have studied the effects of fullerene crystallinity during heat treatment in model structures consisting of a layer of poly(3-hexylthiophene) (P3HT) sandwiched between two layers of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Utilizing a combination of focused ion-beam milling and energy-filtered transmission electron microscopy, we monitored the local changes in phase distribution as a function of annealing time at 140 °C. In both cases, dissolution of PCBM within the surrounding P3HT was directly visualized and quantitatively described. In the absence of crystalline PCBM, the overall phase distribution remained stable after intermediate annealing times up to 60 s, whereas microscale PCBM aggregates were observed after annealing for 300 s. Aggregate growth proceeded vertically from the substrate interface via uptake of PCBM from the surrounding region, resulting in a large PCBM-depleted region in their vicinity. When precrystallized PCBM was present, amorphous PCBM was observed to segregate from the intermediate P3HT layer and ripen the crystalline PCBM underneath, owing to the far lower solubility of crystalline PCBM within P3HT. This process occurred rapidly, with segregation already evident after annealing for 10 s and with uptake of nearly all of the amorphous PCBM by the crystalline layer after 60 s. No microscale aggregates were observed in the precrystallized system, even after annealing for 300 s.

  12. SeqX: a tool to detect, analyze and visualize residue co-locations in protein and nucleic acid structures

    Directory of Open Access Journals (Sweden)

    Fördös Gergely

    2005-07-01

    Full Text Available Abstract Background The interacting residues of protein and nucleic acid sequences are close to each other – they are co-located. Structure databases (like Protein Data Bank, PDB and Nucleic Acid Data Bank, NDB contain all information about these co-locations; however it is not an easy task to penetrate this complex information. We developed a JAVA tool, called SeqX for this purpose. Results SeqX tool is useful to detect, analyze and visualize residue co-locations in protein and nucleic acid structures. The user a. selects a structure from PDB; b. chooses an atom that is commonly present in every residues of the nucleic acid and/or protein structure(s c. defines a distance from these atoms (3–15 Å. The SeqX tool detects every residue that is located within the defined distances from the defined "backbone" atom(s; provides a DotPlot-like visualization (Residues Contact Map, and calculates the frequency of every possible residue pairs (Residue Contact Table in the observed structure. It is possible to exclude +/- 1 to 10 neighbor residues in the same polymeric chain from detection, which greatly improves the specificity of detections (up to 60% when tested on dsDNA. Results obtained on protein structures showed highly significant correlations with results obtained from literature (p Conclusion The tool is simple and easy to use and provides a quick and reliable visualization and analyses of residue co-locations in protein and nucleic acid structures. Availability and requirements http://janbiro.com/Downloads.html SeqX, Java J2SE Runtime Environment 5.0 (available from [see Additional file 1] http://www.sun.com and at least a 1 GHz processor and with a minimum 256 Mb RAM. Source codes are available from the authors. Additional File 1 SeqX_1.041_05601.jar. see this article Click here for file

  13. A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

    Directory of Open Access Journals (Sweden)

    Dominik Heyers

    Full Text Available The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

  14. A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

    Science.gov (United States)

    Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

    2007-09-26

    The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

  15. The visual light field

    NARCIS (Netherlands)

    Koenderink, J.J.; Pont, S.C.; Doorn, A.J. van; Kappers, A.M.L.; Todd, J.T.

    2007-01-01

    Human observers are sensitive to the ‘(physical) light field' in the sense that they have expectations of how a given object would appear if it were introduced in the scene in front of them at some arbitrary location. Thus the ‘visual light field' is defined even in the ‘empty space' between

  16. Network Visualization Project (NVP)

    Science.gov (United States)

    2016-07-01

    Visualization Project (NVP) by Terry Wen American Society of Engineering Education, Washington, DC Lisa M Marvel Computational and Information Sciences...front-end presentation and construction of the application itself. 15. SUBJECT TERMS computer network traffic, computer network security, computer ...understandable illustration of network communication that is adequate for a generally untrained eye. In accomplishing this, the project will provide a new tool

  17. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...

  18. Differential effect of visual motion adaption upon visual cortical excitability.

    Science.gov (United States)

    Lubeck, Astrid J A; Van Ombergen, Angelique; Ahmad, Hena; Bos, Jelte E; Wuyts, Floris L; Bronstein, Adolfo M; Arshad, Qadeer

    2017-03-01

    The objectives of this study were 1) to probe the effects of visual motion adaptation on early visual and V5/MT cortical excitability and 2) to investigate whether changes in cortical excitability following visual motion adaptation are related to the degree of visual dependency, i.e., an overreliance on visual cues compared with vestibular or proprioceptive cues. Participants were exposed to a roll motion visual stimulus before, during, and after visual motion adaptation. At these stages, 20 transcranial magnetic stimulation (TMS) pulses at phosphene threshold values were applied over early visual and V5/MT cortical areas from which the probability of eliciting a phosphene was calculated. Before and after adaptation, participants aligned the subjective visual vertical in front of the roll motion stimulus as a marker of visual dependency. During adaptation, early visual cortex excitability decreased whereas V5/MT excitability increased. After adaptation, both early visual and V5/MT excitability were increased. The roll motion-induced tilt of the subjective visual vertical (visual dependence) was not influenced by visual motion adaptation and did not correlate with phosphene threshold or visual cortex excitability. We conclude that early visual and V5/MT cortical excitability is differentially affected by visual motion adaptation. Furthermore, excitability in the early or late visual cortex is not associated with an increase in visual reliance during spatial orientation. Our findings complement earlier studies that have probed visual cortical excitability following motion adaptation and highlight the differential role of the early visual cortex and V5/MT in visual motion processing.NEW & NOTEWORTHY We examined the influence of visual motion adaptation on visual cortex excitability and found a differential effect in V1/V2 compared with V5/MT. Changes in visual excitability following motion adaptation were not related to the degree of an individual's visual dependency.

  19. 国际健康素养研究演进路径、研究热点与前沿可视化分析%The Visualization Analysis of Evolution Pathway, Research Hotspots and Research Fronts of International Health Literacy

    Institute of Scientific and Technical Information of China (English)

    姚强; 刘小利; 杜建; 张士靖

    2011-01-01

    The aim of this paper is to reveal the evolution in the latest 30 years, research hotspots and research fronts of Health Literacy. We retrieved the whole documents data by topic word "health literacy" from 1990 to 2010 in SCI, SSCI. Documents are visualized through a number of co-citation maps. which filtered the critical node documents in the evolution of health literacy research by knowledge visualization tool, CiteSpace. We also applied its function of document-noun phrase network ,keywords clusting and burst detecting to analyse the research hotspots and research fronts. 11 critical node documents perfectly showed the evolution pathway of health literacy research, 2 clear clusters and 19 burst terms indicated the research hotspots and research fronts. Health literacy and mental health literacy are two domain research fields of health literacy. Such subjects or fields as connotation of health literacy, health materials' readability, rapid assessment of literacy levels, health education,emergency and chronic disease or infections represented by AIDS are research fronts and development trends in future.%文章目的在于梳理30多年来健康素养领域研究的演进路径,揭示研究热点与研究前沿.为此,将1 990一201 o年s CI、sscI数据库中收录的主题为"健康素养"的论文数据作为研究对象,应用citespace知识可视化软件绘制文献共被引网络图谱,析出健康素养演进过程中的关键节点文献;并应用其文献共引一名词短语混合网络图谱、关键词聚类和膨胀词探测功能分析了研究热点与研究前沿.11篇关键节点文献很好地展示了健康素养领域研完的演进路径,2个明显的聚类以及19个突现词表征了研究热点与研究前沿.文章认为健康素养和精神健康素养是目前两个主流研究领域.健康素养内涵、健康材料的可读性、快速测评工具和方法、健康教育、突发性事件以及以艾滋病为代表的慢性病与传

  20. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia

    OpenAIRE

    Langen, Carolyn D.; Tonya White; Arfan Ikram, M.; Vernooij, Meike W.; Niessen, Wiro J.

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationshi...

  1. Xlink Analyzer: software for analysis and visualization of cross-linking data in the context of three-dimensional structures.

    Science.gov (United States)

    Kosinski, Jan; von Appen, Alexander; Ori, Alessandro; Karius, Kai; Müller, Christoph W; Beck, Martin

    2015-03-01

    Structural characterization of large multi-subunit protein complexes often requires integrating various experimental techniques. Cross-linking mass spectrometry (XL-MS) identifies proximal protein residues and thus is increasingly used to map protein interactions and determine the relative orientation of subunits within the structure of protein complexes. To fully adapt XL-MS as a structure characterization technique, we developed Xlink Analyzer, a software tool for visualization and analysis of XL-MS data in the context of the three-dimensional structures. Xlink Analyzer enables automatic visualization of cross-links, identifies cross-links violating spatial restraints, calculates violation statistics, maps chemically modified surfaces, and allows interactive manipulations that facilitate analysis of XL-MS data and aid designing new experiments. We demonstrate these features by mapping interaction sites within RNA polymerase I and the Rvb1/2 complex. Xlink Analyzer is implemented as a plugin to UCSF Chimera, a standard structural biology software tool, and thus enables seamless integration of XL-MS data with, e.g. fitting of X-ray structures to EM maps. Xlink Analyzer is available for download at http://www.beck.embl.de/XlinkAnalyzer.html.

  2. "Front" hotshet izvinitsja / Aleksandr Ikonnikov

    Index Scriptorium Estoniae

    Ikonnikov, Aleksandr

    2003-01-01

    Põhiliselt vene rahvusest noori ühendava liikumise "Front" esindajad kavatsevad kohtuda USA suursaadikuga Eestis ja vabandada kevadel suursaatkonna ees vägivallatsemisega lõppenud meeleavalduse pärast

  3. VEEVVIE: Visual Explorer for Empirical Visualization, VR and Interaction Experiments.

    Science.gov (United States)

    Papadopoulos, C; Gutenko, I; Kaufman, A E

    2016-01-01

    Empirical, hypothesis-driven, experimentation is at the heart of the scientific discovery process and has become commonplace in human-factors related fields. To enable the integration of visual analytics in such experiments, we introduce VEEVVIE, the Visual Explorer for Empirical Visualization, VR and Interaction Experiments. VEEVVIE is comprised of a back-end ontology which can model several experimental designs encountered in these fields. This formalization allows VEEVVIE to capture experimental data in a query-able form and makes it accessible through a front-end interface. This front-end offers several multi-dimensional visualization widgets with built-in filtering and highlighting functionality. VEEVVIE is also expandable to support custom experimental measurements and data types through a plug-in visualization widget architecture. We demonstrate VEEVVIE through several case studies of visual analysis, performed on the design and data collected during an experiment on the scalability of high-resolution, immersive, tiled-display walls.

  4. Terms of the debate on the format and structure of visual memory.

    Science.gov (United States)

    Suchow, Jordan W; Fougnie, Daryl; Brady, Timothy F; Alvarez, George A

    2014-10-01

    Our ability to actively maintain information in visual memory is strikingly limited. There is considerable debate about why this is so. As with many questions in psychology, the debate is framed dichotomously: Is visual working memory limited because it is supported by only a small handful of discrete "slots" into which visual representations are placed, or is it because there is an insufficient supply of a "resource" that is flexibly shared among visual representations? Here, we argue that this dichotomous framing obscures a set of at least eight underlying questions. Separately considering each question reveals a rich hypothesis space that will be useful for building a comprehensive model of visual working memory. The questions regard (1) an upper limit on the number of represented items, (2) the quantization of the memory commodity, (3) the relationship between how many items are stored and how well they are stored, (4) whether the number of stored items completely determines the fidelity of a representation (vs. fidelity being stochastic or variable), (5) the flexibility with which the memory commodity can be assigned or reassigned to items, (6) the format of the memory representation, (7) how working memories are formed, and (8) how memory representations are used to make responses in behavioral tasks. We reframe the debate in terms of these eight underlying questions, placing slot and resource models as poles in a more expansive theoretical space.

  5. Stability of oblique shock front

    Institute of Scientific and Technical Information of China (English)

    CHEN; Shuxing(陈恕行)

    2002-01-01

    The stability of the weak planar oblique shock front with respect to the perturbation of the wall is discussed. By the analysis of the formation and the global construction of shock and its asymptotic behaviour for stationary supersonic flow along a smooth rigid wall we obtain the stability of the solution containing a weak planar shock front. The stability can be used to single out a physically reasonable solution together with the entropy condition.

  6. The artist emerges: visual art learning alters neural structure and function.

    Science.gov (United States)

    Schlegel, Alexander; Alexander, Prescott; Fogelson, Sergey V; Li, Xueting; Lu, Zhengang; Kohler, Peter J; Riley, Enrico; Tse, Peter U; Meng, Ming

    2015-01-15

    How does the brain mediate visual artistic creativity? Here we studied behavioral and neural changes in drawing and painting students compared to students who did not study art. We investigated three aspects of cognition vital to many visual artists: creative cognition, perception, and perception-to-action. We found that the art students became more creative via the reorganization of prefrontal white matter but did not find any significant changes in perceptual ability or related neural activity in the art students relative to the control group. Moreover, the art students improved in their ability to sketch human figures from observation, and multivariate patterns of cortical and cerebellar activity evoked by this drawing task became increasingly separable between art and non-art students. Our findings suggest that the emergence of visual artistic skills is supported by plasticity in neural pathways that enable creative cognition and mediate perceptuomotor integration. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Movement and visual coding: the structure of visuo-spatial working memory.

    Science.gov (United States)

    Quinn, J G

    2008-03-01

    The influential model of verbal working memory (WM) introduced by Baddeley and Hitch (Recent advances in learning and motivation. Academic, New York, 1974) comprised three interacting component parts; an executive controller and two subservient systems. The two subservient systems, one underpinning verbal processing and the other underpinning visual processing are themselves subdivided. In the verbal system, a passive phonological store is maintained by an active phonological loop, which is able to rehearse the material in the passive store. The visual working memory system has traditionally been thought of as having a similar architecture with a passive visual store being maintained by an active store, which codes in terms of movement over space. The paper discusses the evidence for this relationship in visuo-spatial WM and concludes that the architecture does not fit well with the experimental literature. A direction for future research is suggested.

  8. Radiative magnetized thermal conduction fronts

    Science.gov (United States)

    Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

    1990-01-01

    The evolution of plane-parallel magnetized thermal conduction fronts in the interstellar medium (ISM) was studied. Separating the coronal ISM phase and interstellar clouds, these fronts have been thought to be the site of the intermediate-temperature regions whose presence was inferred from O VI absorption-line studies. The front evolution was followed numerically, starting from the initial discontinuous temperature distribution between the hot and cold medium, and ending in the final cooling stage of the hot medium. It was found that, for the typical ISM pressure of 4000 K/cu cm and the hot medium temperature of 10 to the 6th K, the transition from evaporation to condensation in a nonmagnetized front occurs when the front thickness is 15 pc. This thickness is a factor of 5 smaller than previously estimated. The O VI column densities in both evaporative and condensation stages agree with observations if the initial hot medium temperature Th exceeds 750,000 K. Condensing conduction fronts give better agreement with observed O VI line profiles because of lower gas temperatures.

  9. Reconstruction and Visualization of Fiber and Laminar Structure inthe Normal Human Heart from Ex Vivo DTMRI Data

    Energy Technology Data Exchange (ETDEWEB)

    Rohmer, Damien; Sitek, Arkadiusz; Gullberg, Grant T.

    2006-12-18

    Background - The human heart is composed of a helicalnetwork of muscle fibers. These fibers are organized to form sheets thatare separated by cleavage surfaces. This complex structure of fibers andsheets is responsible for the orthotropic mechanical properties ofcardiac muscle. The understanding of the configuration of the 3D fiberand sheet structure is important for modeling the mechanical andelectrical properties of the heart and changes in this configuration maybe of significant importance to understand the remodeling aftermyocardial infarction.Methods - Anisotropic least square filteringfollowed by fiber and sheet tracking techniques were applied to DiffusionTensor Magnetic Resonance Imaging (DTMRI) data of the excised humanheart. The fiber configuration was visualized by using thin tubes toincrease 3-dimensional visual perception of the complex structure. Thesheet structures were reconstructed from the DTMRI data, obtainingsurfaces that span the wall from the endo- to the epicardium. Allvisualizations were performed using the high-quality ray-tracing softwarePOV-Ray. Results - The fibers are shown to lie in sheets that haveconcave or convex transmural structure which correspond to histologicalstudies published in the literature. The fiber angles varied depending onthe position between the epi- and endocardium. The sheets had a complexstructure that depended on the location within the myocardium. In theapex region the sheets had more curvature. Conclusions - A high-qualityvisualization algorithm applied to demonstrated high quality DTMRI datais able to elicit the comprehension of the complex 3 dimensionalstructure of the fibers and sheets in the heart.

  10. Efficient Structure-Aware Selection Techniques for 3D Point Cloud Visualizations with 2DOF Input

    NARCIS (Netherlands)

    Yu, Lingyun; Efstathiou, Konstantinos; Isenberg, Petra; Isenberg, Tobias

    2012-01-01

    Data selection is a fundamental task in visualization because it serves as a pre-requisite to many follow-up interactions. Efficient spatial selection in 3D point cloud datasets consisting of thousands or millions of particles can be particularly challenging. We present two new techniques, TeddySele

  11. PanViz: interactive visualization of the structure of functionally annotated pangenomes

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David

    2017-01-01

    Script and is available on https://github.com/thomasp85/PanViz A companion R package that facilitates the creation of PanViz visualizations from a range of data formats is released through Bioconductor and is available at https://bioconductor.org/packages/PanVizGenerator CONTACT: thomasp85@gmail...

  12. Efficient Structure-Aware Selection Techniques for 3D Point Cloud Visualizations with 2DOF Input

    NARCIS (Netherlands)

    Yu, Lingyun; Efstathiou, Konstantinos; Isenberg, Petra; Isenberg, Tobias

    2012-01-01

    Data selection is a fundamental task in visualization because it serves as a pre-requisite to many follow-up interactions. Efficient spatial selection in 3D point cloud datasets consisting of thousands or millions of particles can be particularly challenging. We present two new techniques,

  13. JDet: interactive calculation and visualization of function-related conservation patterns in multiple sequence alignments and structures.

    Science.gov (United States)

    Muth, Thilo; García-Martín, Juan A; Rausell, Antonio; Juan, David; Valencia, Alfonso; Pazos, Florencio

    2012-02-15

    We have implemented in a single package all the features required for extracting, visualizing and manipulating fully conserved positions as well as those with a family-dependent conservation pattern in multiple sequence alignments. The program allows, among other things, to run different methods for extracting these positions, combine the results and visualize them in protein 3D structures and sequence spaces. JDet is a multiplatform application written in Java. It is freely available, including the source code, at http://csbg.cnb.csic.es/JDet. The package includes two of our recently developed programs for detecting functional positions in protein alignments (Xdet and S3Det), and support for other methods can be added as plug-ins. A help file and a guided tutorial for JDet are also available.

  14. Investigation on the near-wake flow structures of a utility-scale wind turbine using snowflake based flow visualization

    Science.gov (United States)

    Dasari, Teja; Toloui, Mostafa; Guala, Michele; Hong, Jiarong

    2015-11-01

    Super-large-scale particle image velocimetry and flow visualization techniques using natural snow particles have been shown as an effective tool to probe the structure of the flow around full-scale wind turbines (Hong et al. Nature Comm. 2014). Here we present a follow-up study based on the data collected during a deployment around the 2.5 MW wind turbine at EOLOS Wind Energy Research Station on April, 4th, 2014. The dataset includes the snow visualization of flow fields from different perspectives in the near wake of the turbine. The motions of the dominant coherent structures including tip, blade root, hub and tower vortices, represented by the snow voids, are examined with the objective of quantifying and correlating their behavior with the meteorological and turbine operating conditions. Some preliminary studies on flow-structure interaction are also performed by correlating the data from strain gauges, accelerometers mounted on the turbine blades, with the flow measurements. The statistical analysis of the motions of blade induced vortices shows a clear impact of atmospheric turbulence and vortex interaction on flow development in the near wake. The result further indicates a strong connection between near-wake vorticity field, turbine operation and structure deformations. The work was supported by National Science Foundation (NSF-CBET-1454259) and the research infrastructure was supported by Department of Energy.

  15. Wave front distortion based fluid flow imaging

    Science.gov (United States)

    Iffa, Emishaw; Heidrich, Wolfgang

    2013-03-01

    In this paper, a transparent flow surface reconstruction based on wave front distortion is investigated. A camera lens is used to focus the image formed by the micro-lens array to the camera imaging plane. The irradiance of the captured image is transformed to frequency spectrum and then the x and y spatial components are separated. A rigid spatial translation followed by low pass filtering yields a single frequency component of the image intensity. Index of refraction is estimated from the inverse Fourier transform of the spatial frequency spectrum of the irradiance. The proposed method is evaluated with synthetic data of a randomly generated index of refraction value and used to visualize a fuel injection volumetric data.

  16. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...... also argue that passing only relevant data from the database will substantially reduce the overall load of the visualization system. We propose the system Incremental Visualizer for Visible Objects (IVVO) which considers visible objects and enables incremental visualization along the observer movement...... visibility ranges and show that considering visibility ranges is crucial when considering incremental visible object extraction....

  17. Infrared thermography fails to visualize stimulation-induced meridian-like structures: comment by Rixin Chen and Zhimai Lv and reply from Gerhard Litscher

    Science.gov (United States)

    2011-01-01

    A comment on G. Litscher: Infrared thermography fails to visualize stimulation-induced meridian-like structures. Biomed. Eng. OnLine 2005, 4:38 (15 June 2005), with a response by the author. PMID:21906400

  18. Severe structural and functional visual system damage leads to profound loss of vision-related quality of life in patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Schmidt, Felix; Zimmermann, Hanna; Mikolajczak, Janine; Oertel, Frederike C; Pache, Florence; Weinhold, Maria; Schinzel, Johann; Bellmann-Strobl, Judith; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

    2017-01-01

    Neuromyelitis optica spectrum disorders (NMOSD) are characterized by devastating optic neuritis attacks causing more structural damage and visual impairment than in multiple sclerosis (MS). The objective of this study was to compare vision-related quality of life in NMOSD and MS patients and correlate it to structural retinal damage and visual function. Thirty-one NMOSD and 31 matched MS patients were included. Vision-related quality of life was assessed with the 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). All patients underwent retinal optical coherence tomography and visual acuity and contrast sensitivity measurements. Vision-related quality of life was reduced in NMOSD compared to MS patients. This difference was driven by a higher incidence of bilateral and more severe optic neuritis in the NMOSD group. Retinal thinning and visual impairment were significantly greater in the NMOSD cohort. Lower vision-related quality of life was associated with more retinal damage and reduced visual function as assessed by visual acuity and contrast sensitivity. NMOSD-related bilateral ON-attacks cause severe structural damage and visual impairment that lead to severe loss of vision-related quality of life. The NEI-VFQ is a helpful tool to monitor vision-related quality of life in NMOSD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Visualizing the topical structure of the medical sciences: a self-organizing map approach.

    Directory of Open Access Journals (Sweden)

    André Skupin

    Full Text Available BACKGROUND: We implement a high-resolution visualization of the medical knowledge domain using the self-organizing map (SOM method, based on a corpus of over two million publications. While self-organizing maps have been used for document visualization for some time, (1 little is known about how to deal with truly large document collections in conjunction with a large number of SOM neurons, (2 post-training geometric and semiotic transformations of the SOM tend to be limited, and (3 no user studies have been conducted with domain experts to validate the utility and readability of the resulting visualizations. Our study makes key contributions to all of these issues. METHODOLOGY: Documents extracted from Medline and Scopus are analyzed on the basis of indexer-assigned MeSH terms. Initial dimensionality is reduced to include only the top 10% most frequent terms and the resulting document vectors are then used to train a large SOM consisting of over 75,000 neurons. The resulting two-dimensional model of the high-dimensional input space is then transformed into a large-format map by using geographic information system (GIS techniques and cartographic design principles. This map is then annotated and evaluated by ten experts stemming from the biomedical and other domains. CONCLUSIONS: Study results demonstrate that it is possible to transform a very large document corpus into a map that is visually engaging and conceptually stimulating to subject experts from both inside and outside of the particular knowledge domain. The challenges of dealing with a truly large corpus come to the fore and require embracing parallelization and use of supercomputing resources to solve otherwise intractable computational tasks. Among the envisaged future efforts are the creation of a highly interactive interface and the elaboration of the notion of this map of medicine acting as a base map, onto which other knowledge artifacts could be overlaid.

  20. Basic level category structure emerges gradually across human ventral visual cortex.

    Science.gov (United States)

    Iordan, Marius Cătălin; Greene, Michelle R; Beck, Diane M; Fei-Fei, Li

    2015-07-01

    Objects can be simultaneously categorized at multiple levels of specificity ranging from very broad ("natural object") to very distinct ("Mr. Woof"), with a mid-level of generality (basic level: "dog") often providing the most cognitively useful distinction between categories. It is unknown, however, how this hierarchical representation is achieved in the brain. Using multivoxel pattern analyses, we examined how well each taxonomic level (superordinate, basic, and subordinate) of real-world object categories is represented across occipitotemporal cortex. We found that, although in early visual cortex objects are best represented at the subordinate level (an effect mostly driven by low-level feature overlap between objects in the same category), this advantage diminishes compared to the basic level as we move up the visual hierarchy, disappearing in object-selective regions of occipitotemporal cortex. This pattern stems from a combined increase in within-category similarity (category cohesion) and between-category dissimilarity (category distinctiveness) of neural activity patterns at the basic level, relative to both subordinate and superordinate levels, suggesting that successive visual areas may be optimizing basic level representations.

  1. Visual cortical areas of the mouse: comparison of parcellation and network structure with primates.

    Science.gov (United States)

    Laramée, Marie-Eve; Boire, Denis

    2014-01-01

    Brains have evolved to optimize sensory processing. In primates, complex cognitive tasks must be executed and evolution led to the development of large brains with many cortical areas. Rodents do not accomplish cognitive tasks of the same level of complexity as primates and remain with small brains both in relative and absolute terms. But is a small brain necessarily a simple brain? In this review, several aspects of the visual cortical networks have been compared between rodents and primates. The visual system has been used as a model to evaluate the level of complexity of the cortical circuits at the anatomical and functional levels. The evolutionary constraints are first presented in order to appreciate the rules for the development of the brain and its underlying circuits. The organization of sensory pathways, with their parallel and cross-modal circuits, is also examined. Other features of brain networks, often considered as imposing constraints on the development of underlying circuitry, are also discussed and their effect on the complexity of the mouse and primate brain are inspected. In this review, we discuss the common features of cortical circuits in mice and primates and see how these can be useful in understanding visual processing in these animals.

  2. Arnheim's Gestalt Theory of Visual Balance: Examining the Compositional Structure of Art Photographs and Abstract Images

    Directory of Open Access Journals (Sweden)

    I C McManus

    2011-08-01

    Full Text Available In Art and Visual Perception, Rudolf Arnheim, following on from Denman Ross's A Theory of Pure Design, proposed a Gestalt theory of visual composition. The current paper assesses a physicalist interpretation of Arnheim's theory, calculating an image's centre of mass (CoM. Three types of data are used: a large, representative collection of art photographs of recognised quality; croppings by experts and non-experts of photographs; and Ross and Arnheim's procedure of placing a frame around objects such as Arnheim's two black disks. Compared with control images, the CoM of art photographs was closer to an axis (horizontal, vertical, or diagonal, as was the case for photographic croppings. However, stronger, within-image, paired comparison studies, comparing art photographs with the CoM moved on or off an axis (the “gamma-ramp study”, or comparing adjacent croppings on or off an axis (the “spider-web study”, showed no support for the Arnheim-Ross theory. Finally, studies moving a frame around two disks, of different size, greyness, or background, did not support Arnheim's Gestalt theory. Although the detailed results did not support the Arnheim-Ross theory, several significant results were found which clearly require explanation by any adequate theory of the aesthetics of visual composition.

  3. Effects of repetitive low-level blast exposure on visual systems and ocular structures

    Directory of Open Access Journals (Sweden)

    José E. Capó-Aponte, OD, PhD

    2015-06-01

    Full Text Available The purpose of this study was to determine whether repetitive exposure to low-level blasts during military breacher training produces acute and cumulative damage to the ocular tissues or visual system. The effects of low-level blast exposure on high-contrast visual acuity, contrast sensitivity, oculomotor function, color vision, visual field (VF, pupillary light reflex, corneal endothelial cell density (ECD, macular thickness, retinal nerve fiber layer thickness, and cup-to-disc ratio were assessed using a battery of standard clinical ophthalmic tests administered 10 times over a 2-year period. Data from nine male breacher instructors (Cadre were compared with data from four male breacher engineers (Control. The Cadre group showed higher vertical deviation at near than the Control group over time. The VF mean deviation on the left eye tended to be worse in the Cadre group throughout the study, suggesting a decrease in VF sensitivity (Cadre: –0.20 +/– 0.15 dB; Control: 1.05 +/– 0.15 dB; p = 0.03. The Cadre group had a reduced ECD (right eye: Cadre 2,478 cells/mm2 vs Control 2,808 cells/mm2, p = 0.02; left eye: Cadre 2,562 cells/mm2 vs Control 2,892 cells/mm2, p = 0.03. These results suggest that even low-level primary blast has the potential to produce occult eye injury.

  4. Arnheim's Gestalt theory of visual balance: Examining the compositional structure of art photographs and abstract images.

    Science.gov (United States)

    McManus, I C; Stöver, Katharina; Kim, Do

    2011-01-01

    In Art and Visual Perception, Rudolf Arnheim, following on from Denman Ross's A Theory of Pure Design, proposed a Gestalt theory of visual composition. The current paper assesses a physicalist interpretation of Arnheim's theory, calculating an image's centre of mass (CoM). Three types of data are used: a large, representative collection of art photographs of recognised quality; croppings by experts and non-experts of photographs; and Ross and Arnheim's procedure of placing a frame around objects such as Arnheim's two black disks. Compared with control images, the CoM of art photographs was closer to an axis (horizontal, vertical, or diagonal), as was the case for photographic croppings. However, stronger, within-image, paired comparison studies, comparing art photographs with the CoM moved on or off an axis (the 'gamma-ramp study'), or comparing adjacent croppings on or off an axis (the 'spider-web study'), showed no support for the Arnheim-Ross theory. Finally, studies moving a frame around two disks, of different size, greyness, or background, did not support Arnheim's Gestalt theory. Although the detailed results did not support the Arnheim-Ross theory, several significant results were found which clearly require explanation by any adequate theory of the aesthetics of visual composition.

  5. CORRELATION OF MICROVASCULAR STRUCTURES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WITH VISUAL ACUITY IN RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Kang, Joon-Won; Yoo, Romi; Jo, Youn Hye; Kim, Hyung Chan

    2017-09-01

    To analyze the correlation of superficial and deep capillary plexuses using optical coherence tomography (OCT) angiography with visual acuity in eyes with retinal vein occlusion (RVO). We retrospectively reviewed the medical records of 33 patients with retinal vein occlusion (RVO; branch retinal vein occlusion in 21 patients, central retinal vein occlusion in 12 patients) and included 33 healthy subjects as a control group, who were evaluated by OCT angiography. The OCT angiography was performed on a 3 mm × 3-mm region centered on the fovea and parafoveal area. The foveal avascular zone (FAZ), and foveal and parafoveal vascular density (VD) in superficial and deep vascular plexuses were analyzed using OCT angiography. The area of superficial and deep FAZ in eyes with RVO were larger than those in fellow eyes and control eyes (P = 0.034, P = 0.018). The superficial and deep parafoveal VDs in eyes with RVO were significantly lower than those in fellow eyes and control eyes (P = 0.001, Pretinal vein occlusion (85.7%) showed a high concordance rate with respect to the location of branch retinal vein occlusion and the lowest parafoveal VD area. The multivariate analysis showed that the deep parafoveal VD was associated with best-corrected visual acuity. The OCT angiography allows to detect FAZ enlargement, increased parafoveal capillary nonperfusion, and decreased parafoveal VD in eyes with RVO. The area of superficial FAZ and the parafoveal VD are correlated with best-corrected visual acuity in eyes with RVO.

  6. Convective chemical fronts in a Poiseuille flow.

    Science.gov (United States)

    Vasquez, Desiderio A

    2007-11-01

    Autocatalytic reaction fronts propagating in a Poiseuille flow present a change of speed and curvature depending on the strength of the flow and on the direction of front propagation. These chemical fronts separate reacted and unreacted fluids of different densities, consequently convection will always be present due to the horizontal density gradient of the curved front. In this paper, we find the change of speed caused by gravity for fronts propagating in vertical tubes under a Poiseuille flow. For small density differences, we find axisymmetric fronts. Our theory predicts a transition to nonaxisymmetric fronts as the distance between the walls is increased. The transition depends on the average speed of the Poiseuille flow.

  7. [EXPERIMENTAL TESTING OF THE OPERATOR'S PERCEPTION OF SYMBOLIC INFORMATION ON THE HELMET-MOUNTED DISPLAY DEPENDING ON THE STRUCTURAL COMPLEXITY OF VISUAL ENVIRONMENT].

    Science.gov (United States)

    Lapa, V V; Ivanov, A I; Davydov, V V; Ryabinin, V A; Golosov S Yu

    2015-01-01

    The experiments showed that pilot's perception of symbolic information on the helmet-mounted display (HMD) depends on type of HMD (mono- or binocular), and structural complexity of the background image. Complex background extends time and increases errors in perception, particularly when monocular HMD is used. In extremely complicated visual situations (symbolic information on a background intricately structured by supposition of a TV image on real visual environment) significantly increases time and lowers precision of symbols perception no matter what the HMD type.

  8. D Visualization of a Timber Frame Historic Building: Partite Usage and its Impact on the Structural System

    Science.gov (United States)

    Günay, S.

    2017-08-01

    Throughout their lifetime, historic buildings might be altered for different kind of usage for different purposes. If this new function or new usage requires utilization of the building in separate units, this separation might affect the historic building's functionality and structure and as a result its overall condition. Yorguc Pasa Mansion conservation project was prepared as a part of the Middle East Technical University (METU) Master's Program in Documentation and Conservation of Historic Monuments and Sites for the historic Yorguc Pasa Mansion. The mansion is a 19th century Ottoman Period timber frame building in Amasya, a Black Sea Region city in Turkey that has traces from different civilizations such as Hittites, Greeks, Romans and Ottomans. This paper aims to discuss the affects of the partite usage on structural conditions of timber frame buildings with the case study of Amasya Yorguc Pasa Mansion through the 3D visualized structural systems.

  9. Effect of visual experience on structural organization of the human brain: a voxel based morphometric study using DARTEL.

    Science.gov (United States)

    Modi, Shilpi; Bhattacharya, Manisha; Singh, Namita; Tripathi, Rajendra Prasad; Khushu, Subash

    2012-10-01

    To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Effect of visual experience on structural organization of the human brain: A voxel based morphometric study using DARTEL

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Shilpi, E-mail: modi_shilpi@yahoo.co.in [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Bhattacharya, Manisha, E-mail: manishab10@gmail.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Singh, Namita, E-mail: namita23m@gmail.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Tripathi, Rajendra Prasad, E-mail: director@inmas.drdo.in [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Khushu, Subash, E-mail: skhushu@yahoo.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India)

    2012-10-15

    Objective: To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. Materials and methods: High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. Results: VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Conclusion: Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness.

  11. Detection and visualization of non-linear structures in large datasets using Exploratory Projection Pursuit Laboratory (EPP-Lab software

    Directory of Open Access Journals (Sweden)

    Souad Larabi Marie-Sainte

    2017-01-01

    Full Text Available This article consists of using biologically inspired algorithms in order to detect potentially interesting structures in large and multidimensional data sets. Data exploration and the detection of interesting structures are based on the use of Projection Pursuit that involves the definition and the optimization of an index associated with each direction or projection. The optimization of a projection index should provide a set of multiple optima that is expected to correspond to interesting graphical representations in low dimensional space. The implementation of the bio-inspired algorithms along with the projection pursuit develops a new software called EPP-Lab. Projection pursuit is widely used in different scientific domains (biology, pharmacy, bioinformatics, biometry, etc but not widely present in the well-known softwares. EPP-Lab is dedicated to recognize and visualize clusters and outlying observations on one dimension from high dimensional and multivariate data sets. It includes different statistical techniques for results analysis. It provides several features and gives the user the option to adjust the parameters of the selected bio-inspired methods or to use defaults values. EPP-Lab is a unique software for detection, visualization and analysis of non-linear structures. The performance of this tool has been validated by testing different real and simulated data sets.

  12. The influence of the visual modality on language structure and conventionalization: insights from sign language and gesture.

    Science.gov (United States)

    Perniss, Pamela; Özyürek, Asli; Morgan, Gary

    2015-01-01

    For humans, the ability to communicate and use language is instantiated not only in the vocal modality but also in the visual modality. The main examples of this are sign languages and (co-speech) gestures. Sign languages, the natural languages of Deaf communities, use systematic and conventionalized movements of the hands, face, and body for linguistic expression. Co-speech gestures, though non-linguistic, are produced in tight semantic and temporal integration with speech and constitute an integral part of language together with speech. The articles in this issue explore and document how gestures and sign languages are similar or different and how communicative expression in the visual modality can change from being gestural to grammatical in nature through processes of conventionalization. As such, this issue contributes to our understanding of how the visual modality shapes language and the emergence of linguistic structure in newly developing systems. Studying the relationship between signs and gestures provides a new window onto the human ability to recruit multiple levels of representation (e.g., categorical, gradient, iconic, abstract) in the service of using or creating conventionalized communicative systems.

  13. Identifying shared genetic structure patterns among Pacific Northwest forest taxa: insights from use of visualization tools and computer simulations.

    Directory of Open Access Journals (Sweden)

    Mark P Miller

    Full Text Available BACKGROUND: Identifying causal relationships in phylogeographic and landscape genetic investigations is notoriously difficult, but can be facilitated by use of multispecies comparisons. METHODOLOGY/PRINCIPAL FINDINGS: We used data visualizations to identify common spatial patterns within single lineages of four taxa inhabiting Pacific Northwest forests (northern spotted owl: Strix occidentalis caurina; red tree vole: Arborimus longicaudus; southern torrent salamander: Rhyacotriton variegatus; and western white pine: Pinus monticola. Visualizations suggested that, despite occupying the same geographical region and habitats, species responded differently to prevailing historical processes. S. o. caurina and P. monticola demonstrated directional patterns of spatial genetic structure where genetic distances and diversity were greater in southern versus northern locales. A. longicaudus and R. variegatus displayed opposite patterns where genetic distances were greater in northern versus southern regions. Statistical analyses of directional patterns subsequently confirmed observations from visualizations. Based upon regional climatological history, we hypothesized that observed latitudinal patterns may have been produced by range expansions. Subsequent computer simulations confirmed that directional patterns can be produced by expansion events. CONCLUSIONS/SIGNIFICANCE: We discuss phylogeographic hypotheses regarding historical processes that may have produced observed patterns. Inferential methods used here may become increasingly powerful as detailed simulations of organisms and historical scenarios become plausible. We further suggest that inter-specific comparisons of historical patterns take place prior to drawing conclusions regarding effects of current anthropogenic change within landscapes.

  14. Scientific Visualization and Computational Science: Natural Partners

    Science.gov (United States)

    Uselton, Samuel P.; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    Scientific visualization is developing rapidly, stimulated by computational science, which is gaining acceptance as a third alternative to theory and experiment. Computational science is based on numerical simulations of mathematical models derived from theory. But each individual simulation is like a hypothetical experiment; initial conditions are specified, and the result is a record of the observed conditions. Experiments can be simulated for situations that can not really be created or controlled. Results impossible to measure can be computed.. Even for observable values, computed samples are typically much denser. Numerical simulations also extend scientific exploration where the mathematics is analytically intractable. Numerical simulations are used to study phenomena from subatomic to intergalactic scales and from abstract mathematical structures to pragmatic engineering of everyday objects. But computational science methods would be almost useless without visualization. The obvious reason is that the huge amounts of data produced require the high bandwidth of the human visual system, and interactivity adds to the power. Visualization systems also provide a single context for all the activities involved from debugging the simulations, to exploring the data, to communicating the results. Most of the presentations today have their roots in image processing, where the fundamental task is: Given an image, extract information about the scene. Visualization has developed from computer graphics, and the inverse task: Given a scene description, make an image. Visualization extends the graphics paradigm by expanding the possible input. The goal is still to produce images; the difficulty is that the input is not a scene description displayable by standard graphics methods. Visualization techniques must either transform the data into a scene description or extend graphics techniques to display this odd input. Computational science is a fertile field for visualization

  15. Miscible displacement fronts of shear thinning fluids inside rough fractures

    CERN Document Server

    Boschan, A; Ippolito, I; Chertcoff, R; Hulin, J P; Boschan, Alexandro; Auradou, Harold; Ippolito, Irene; Chertcoff, Ricardo; Hulin, Jean-Pierre

    2006-01-01

    The miscible displacement of a shear-thinning fluid by another of same rheological properties is studied experimentally in a transparent fracture by an optical technique imaging relative concentration distributions. The fracture walls have complementary self-affine geometries and are shifted laterally in the direction perpendicular to the mean flow velocity {\\bf U} : the flow field is strongly channelized and macro dispersion controls the front structure for P\\'{e}clet numbers above a few units. The global front width increases then linearly with time and reflects the velocity distribution between the different channels. In contrast, at the local scale, front spreading is similar to Taylor dispersion between plane parallel surfaces. Both dispersion mechanisms depend strongly on the fluid rheology which shifts from Newtonian to shear-thinning when the flow rate increases. In the latter domain, increasing the concentration enhances the global front width but reduces both Taylor dispersion (due to the flattening...

  16. The structure of the nucleosome core particle of chromatin in chicken erythrocytes visualized by using atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    ZHAOHUI; YIZHANG; 等

    1999-01-01

    The structure of the nuclosome core particle of chromatin in chicken erythrocytes has been examined by using AFM.The 146 bp of DNA wrapped twice around the core histone octamer are clearly visualized.Both the ends of entry/exit of linker DNA are also demonstrated.The dimension of the nucleosome core particles is - 1-4 nm in height and - 13-22 nm in width.In addition,superbeads (width of - 48-57 nm,height of - 2-3 nm )are occasionally revealed,two turns of DNA around the core particles are also detected.

  17. Structural visualization of expert nursing: Development of an assessment and intervention algorithm for delirium following abdominal and thoracic surgeries.

    Science.gov (United States)

    Watanuki, Shigeaki; Takeuchi, Tomiko; Matsuda, Yoshimi; Terauchi, Hidemasa; Takahashi, Yukiko; Goshima, Mitsuko; Nishimoto, Yutaka; Tsuru, Satoko

    2006-01-01

    An assessment and intervention algorithm for delirium following abdominal and thoracic surgeries was developed based upon the current knowledge-base. The sources of information included literature and clinical expertise. The assessment and intervention algorithm was structured and visualized so that patient-tailored and risk-stratified prediction/prevention, assessment, and intervention could be carried out. Accumulation of clinical outcome data is necessary in the future validation study to identify the relative weight of risk factors and clinical utility of the algorithm.

  18. How to detect and visualize extinction thresholds for structured PVA models

    NARCIS (Netherlands)

    Hildenbrandt, H.; Grimm, V.

    2006-01-01

    An extinction threshold is a population size below which extinction risk increases to beyond critical values. However, detecting extinction thresholds for structured population models is not straightforward because many different population structures may correspond to the same population size. More

  19. Car Front Towing Hook Analysis and Structural Improvements Based on CAE%基于 CAE 技术的轿车拖钩分析与结构改进

    Institute of Scientific and Technical Information of China (English)

    明宇

    2016-01-01

    In order to improve the development quality of car towing hook, through a car front towing hook design and development, we analyze the strength of towing hook and local parts using CAE. By comparison with the results and the target value, we evaluate its structural strength and determine the improvement program. The improvement program shows that both the strength and residual deformation meet the requirements.%为提高汽车拖钩的开发质量,以某轿车前拖钩设计开发为例,应用 CAE 技术进行拖钩及局部件的强度分析,通过分析结果与目标值对比,对其结构强度进行评价;并根据分析结果确定改进方案;通过对改进方案的校核验证,结果表明改进方案满足设计要求。

  20. Center for computation and visualization of geometric structures. [Annual], Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-12

    The mission of the Center is to establish a unified environment promoting research, education, and software and tool development. The work is centered on computing, interpreted in a broad sense to include the relevant theory, development of algorithms, and actual implementation. The research aspects of the Center are focused on geometry; correspondingly the computational aspects are focused on three (and higher) dimensional visualization. The educational aspects are likewise centered on computing and focused on geometry. A broader term than education is `communication` which encompasses the challenge of explaining to the world current research in mathematics, and specifically geometry.

  1. Visualization of Structured Packing with Laser Induced Fluorescence Technique:Two-Dimensional Measurement of Liquid Concentration Distribution

    Institute of Scientific and Technical Information of China (English)

    刘伯潭; 申言同; 张会书; 刘春江; 唐忠利; 袁希钢

    2016-01-01

    A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional meas-urement of the liquid concentration distribution in the 250Y structured packing sheet. The experimental structured packing sheet was made of perspex so that the laser could pass through it. The visualization of the distribution of the liquid concentration in the structured packing sheet was realized. The calibration of the thickness and liquid concentration was carried out firstly and the regression formulaI=kcd was acquired, in which concentrationc and the liquid film thicknessd were both considered. Then the liquid feed of uniform tracer(rhodamine)concentration entered the perspex structured packing from the top under different spraying densities. The corresponding thickness of liquid film on the packing was calculated. Finally, tracer(rhodamine)with a high concentration was injected only at one fixed point of the structured packing under different spraying densities of the liquid. With the known liquid film thickness, the concentration distribution of the tracer can be calculated inside the structured packing sheet.

  2. Align the Front End First.

    Science.gov (United States)

    Perry, Jim

    1995-01-01

    Discussion of management styles and front-end analysis focuses on a review of Douglas McGregor's theories. Topics include Theories X, Y, and Z; leadership skills; motivational needs of employees; intrinsic and extrinsic rewards; and faulty implementation of instructional systems design processes. (LRW)

  3. Multiple WH-Fronting Constructions.

    Science.gov (United States)

    Rudin, Catherine

    The unique position of WH words in Slavic languages is discussed, with specific reference to Bulgarian and Serbo-Croatian. The multiple fronting characteristics of Bulgarian and Serbo-Croatian differ in terms of the following positions and behaviors: extraction from embedded questions; clitic placement and other indications of constituent status;…

  4. The Light-Front Vacuum

    CERN Document Server

    Herrmann, Marc

    2015-01-01

    Background: The vacuum in the light-front representation of quantum field theory is trivial while vacuum in the equivalent canonical representation of the same theory is non-trivial. Purpose: Understand the relation between the vacuum in light-front and canonical representations of quantum field theory and the role of zero-modes in this relation. Method: Vacuua are defined as linear functionals on an algebra of field operators. The role of the algebra in the definition of the vacuum is exploited to understand this relation. Results: The vacuum functional can be extended from the light-front Fock algebra to an algebra of local observables. The extension to the algebra of local observables is responsible for the inequivalence. The extension defines a unitary mapping between the physical representation of the local algebra and a sub-algebra of the light-front Fock algebra. Conclusion: There is a unitary mapping from the physical representation of the algebra of local observables to a sub-algebra of the light-fro...

  5. Align the Front End First.

    Science.gov (United States)

    Perry, Jim

    1995-01-01

    Discussion of management styles and front-end analysis focuses on a review of Douglas McGregor's theories. Topics include Theories X, Y, and Z; leadership skills; motivational needs of employees; intrinsic and extrinsic rewards; and faulty implementation of instructional systems design processes. (LRW)

  6. Light Front Fermion Model Propagation

    Institute of Scientific and Technical Information of China (English)

    Jorge Henrique Sales; Alfredo Takashi Suzuki

    2013-01-01

    In this work we consider the propagation of two fermion fields interacting with each other by the exchange of intermediate scalar bosons in the light front.We obtain the corrections up to fourth order in the coupling constant using hierarchical equations in order to obtain the bound state equation (Bethe-Salpeter equation).

  7. FAZIA front-end electronics

    OpenAIRE

    Salomon F.; Edelbruck P.; Brulin G.; Boiano A.; Tortone G.; Ordine A.; Bini M.; Barlini S.; Valdré S.

    2015-01-01

    FAZIA is a multi-detector specifically designed to optimize ion identification in heavy-ion experiments. Its electronic is fully digital; it was designed in the laboratories of the collaboration. This paper presents the front-end part of this electronic.

  8. FAZIA front-end electronics

    Directory of Open Access Journals (Sweden)

    Salomon F.

    2015-01-01

    Full Text Available FAZIA is a multi-detector specifically designed to optimize ion identification in heavy-ion experiments. Its electronic is fully digital; it was designed in the laboratories of the collaboration. This paper presents the front-end part of this electronic.

  9. Timescales of multineuronal activity patterns reflect temporal structure of visual stimuli.

    Directory of Open Access Journals (Sweden)

    Ovidiu F Jurjuţ

    Full Text Available The investigation of distributed coding across multiple neurons in the cortex remains to this date a challenge. Our current understanding of collective encoding of information and the relevant timescales is still limited. Most results are restricted to disparate timescales, focused on either very fast, e.g., spike-synchrony, or slow timescales, e.g., firing rate. Here, we investigated systematically multineuronal activity patterns evolving on different timescales, spanning the whole range from spike-synchrony to mean firing rate. Using multi-electrode recordings from cat visual cortex, we show that cortical responses can be described as trajectories in a high-dimensional pattern space. Patterns evolve on a continuum of coexisting timescales that strongly relate to the temporal properties of stimuli. Timescales consistent with the time constants of neuronal membranes and fast synaptic transmission (5-20 ms play a particularly salient role in encoding a large amount of stimulus-related information. Thus, to faithfully encode the properties of visual stimuli the brain engages multiple neurons into activity patterns evolving on multiple timescales.

  10. Visual Odometry Based on Structural Matching of Local Invariant Features Using Stereo Camera Sensor

    Directory of Open Access Journals (Sweden)

    Antonio Bandera

    2011-07-01

    Full Text Available This paper describes a novel sensor system to estimate the motion of a stereo camera. Local invariant image features are matched between pairs of frames and linked into image trajectories at video rate, providing the so-called visual odometry, i.e., motion estimates from visual input alone. Our proposal conducts two matching sessions: the first one between sets of features associated to the images of the stereo pairs and the second one between sets of features associated to consecutive frames. With respect to previously proposed approaches, the main novelty of this proposal is that both matching algorithms are conducted by means of a fast matching algorithm which combines absolute and relative feature constraints. Finding the largest-valued set of mutually consistent matches is equivalent to finding the maximum-weighted clique on a graph. The stereo matching allows to represent the scene view as a graph which emerge from the features of the accepted clique. On the other hand, the frame-to-frame matching defines a graph whose vertices are features in 3D space. The efficiency of the approach is increased by minimizing the geometric and algebraic errors to estimate the final displacement of the stereo camera between consecutive acquired frames. The proposed approach has been tested for mobile robotics navigation purposes in real environments and using different features. Experimental results demonstrate the performance of the proposal, which could be applied in both industrial and service robot fields.

  11. Visual odometry based on structural matching of local invariant features using stereo camera sensor.

    Science.gov (United States)

    Núñez, Pedro; Vázquez-Martín, Ricardo; Bandera, Antonio

    2011-01-01

    This paper describes a novel sensor system to estimate the motion of a stereo camera. Local invariant image features are matched between pairs of frames and linked into image trajectories at video rate, providing the so-called visual odometry, i.e., motion estimates from visual input alone. Our proposal conducts two matching sessions: the first one between sets of features associated to the images of the stereo pairs and the second one between sets of features associated to consecutive frames. With respect to previously proposed approaches, the main novelty of this proposal is that both matching algorithms are conducted by means of a fast matching algorithm which combines absolute and relative feature constraints. Finding the largest-valued set of mutually consistent matches is equivalent to finding the maximum-weighted clique on a graph. The stereo matching allows to represent the scene view as a graph which emerge from the features of the accepted clique. On the other hand, the frame-to-frame matching defines a graph whose vertices are features in 3D space. The efficiency of the approach is increased by minimizing the geometric and algebraic errors to estimate the final displacement of the stereo camera between consecutive acquired frames. The proposed approach has been tested for mobile robotics navigation purposes in real environments and using different features. Experimental results demonstrate the performance of the proposal, which could be applied in both industrial and service robot fields.

  12. Visualization of Social Networks

    NARCIS (Netherlands)

    Boertjes, E.M.; Kotterink, B.; Jager, E.J.

    2011-01-01

    Current visualizations of social networks are mostly some form of node-link diagram. Depending on the type of social network, this can be some treevisualization with a strict hierarchical structure or a more generic network visualization.

  13. Resveratrol Based Oral Nutritional Supplement Produces Long-Term Beneficial Effects on Structure and Visual Function in Human Patients

    Directory of Open Access Journals (Sweden)

    Stuart Richer

    2014-10-01

    Full Text Available Background: Longevinex® (L/RV is a low dose hormetic over-the-counter (OTC oral resveratrol (RV based matrix of red wine solids, vitamin D3 and inositol hexaphosphate (IP6 with established bioavailability, safety, and short-term efficacy against the earliest signs of human atherosclerosis, murine cardiac reperfusion injury, clinical retinal neovascularization, and stem cell survival. We previously reported our short-term findings for dry and wet age-related macular degeneration (AMD patients. Today we report long term (two to three year clinical efficacy. Methods: We treated three patients including a patient with an AMD treatment resistant variant (polypoidal retinal vasculature disease. We evaluated two clinical measures of ocular structure (fundus autofluorescent imaging and spectral domain optical coherence extended depth choroidal imaging and qualitatively appraised changes in macular pigment volume. We further evaluated three clinical measures of visual function (Snellen visual acuity, contrast sensitivity, and glare recovery to a cone photo-stress stimulus. Results: We observed broad bilateral improvements in ocular structure and function over a long time period, opposite to what might be expected due to aging and the natural progression of the patient’s pathophysiology. No side effects were observed. Conclusions: These three cases demonstrate that application of epigenetics has long-term efficacy against AMD retinal disease, when the retinal specialist has exhausted other therapeutic modalities.

  14. Temporally-structured acquisition of multidimensional optical imaging data facilitates visualization of elusive cortical representations in the behaving monkey.

    Science.gov (United States)

    Omer, David B; Hildesheim, Rina; Grinvald, Amiram

    2013-11-15

    Fundamental understanding of higher cognitive functions can greatly benefit from imaging of cortical activity with high spatiotemporal resolution in the behaving non-human primate. To achieve rapid imaging of high-resolution dynamics of cortical representations of spontaneous and evoked activity, we designed a novel data acquisition protocol for sensory stimulation by rapidly interleaving multiple stimuli in continuous sessions of optical imaging with voltage-sensitive dyes. We also tested a new algorithm for the "temporally structured component analysis" (TSCA) of a multidimensional time series that was developed for our new data acquisition protocol, but was tested only on simulated data (Blumenfeld, 2010). In addition to the raw data, the algorithm incorporates prior knowledge about the temporal structure of the data as well as input from other information. Here we showed that TSCA can successfully separate functional signal components from other signals referred to as noise. Imaging of responses to multiple visual stimuli, utilizing voltage-sensitive dyes, was performed on the visual cortex of awake monkeys. Multiple cortical representations, including orientation and ocular dominance maps as well as the hitherto elusive retinotopic representation of orientation stimuli, were extracted in only 10s of imaging, approximately two orders of magnitude faster than accomplished by conventional methods. Since the approach is rather general, other imaging techniques may also benefit from the same stimulation protocol. This methodology can thus facilitate rapid optical imaging explorations in monkeys, rodents and other species with a versatility and speed that were not feasible before.

  15. Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.; /Costa Rica U.

    2012-02-16

    Light-Front Holography is one of the most remarkable features of the AdS/CFT correspondence. In spite of its present limitations it provides important physical insights into the nonperturbative regime of QCD and its transition to the perturbative domain. This novel framework allows hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound-state wavefunctions, and thus the fall-off as a function of the invariant mass of the constituents. The soft-wall holographic model modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics - a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions projected on the free Fock basis provides the complete set of valence and non-valence light-front Fock state wavefunctions {Psi}{sub n/H} (x{sub i}, k{sub {perpendicular}i}, {lambda}{sub i}) which describe the hadron's momentum and spin distributions needed to compute the direct measures of hadron structure at the quark and gluon level, such as elastic and transition form factors, distribution amplitudes, structure functions, generalized parton distributions and transverse

  16. Analysis of sea surface temperature fronts in the Taiwan Strait and its adjacent area using an advanced edge detection method

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A morphology-based edge detection method has been used to study sea surface temperature (SST) fronts in the Taiwan Strait and its adjacent area. The method is based on mathematical morphology with multi-dimensional and multi-structural elements. Using six years’ SST data from September 2002 to August 2008, we distinguished the large SST front like Kuroshio Front as well as the smaller ones: namely Taiwan Bank Front, Zhe-Min Coastal Front and Zhang-Yun Ridge Front. The seasonal and monthly variations of these fronts were also studied. Generally, the SST fronts are stronger in winter but weaker in summer. And the fronts are at their active stage during the period from January to May but at their declining stage during the period from July to October.

  17. The numeric visual evaluation of subsoil structure (SubVESS) under agricultural production

    DEFF Research Database (Denmark)

    Ball, B.C.; Batey, Tom; Munkholm, Lars Juhl

    2015-01-01

    ) and/or natural processes (e.g. shrinkage crack formation). The method was also used to identify differences in subsoil structural quality within fields associated with field traffic levels (Oxisol in Brazil) and with moisture status (Luvisol in France). The focus of SubVESS on structure rather than...

  18. Toolkit for visualization of the cellular structure and organelles in Aspergillus niger.

    Science.gov (United States)

    Buren, Emiel B J Ten; Karrenbelt, Michiel A P; Lingemann, Marit; Chordia, Shreyans; Deng, Ying; Hu, JingJing; Verest, Johanna M; Wu, Vincen; Gonzalez, Teresita J Bello; Heck, Ruben G A van; Odoni, Dorett I; Schonewille, Tom; Straat, Laura van der; Graaff, Leo H de; Passel, Mark W J van

    2014-12-19

    Aspergillus niger is a filamentous fungus that is extensively used in industrial fermentations for protein expression and the production of organic acids. Inherent biosynthetic capabilities, such as the capacity to secrete these biomolecules in high amounts, make A. niger an attractive production host. Although A. niger is renowned for this ability, the knowledge of the molecular components that underlie its production capacity, intercellular trafficking processes and secretion mechanisms is far from complete. Here, we introduce a standardized set of tools, consisting of an N-terminal GFP-actin fusion and codon optimized eforRed chromoprotein. Expression of the GFP-actin construct facilitates visualization of the actin filaments of the cytoskeleton, whereas expression of the chromoprotein construct results in a clearly distinguishable red phenotype. These experimentally validated constructs constitute the first set of standardized A. niger biomarkers, which can be used to study morphology, intercellular trafficking, and secretion phenomena.

  19. Visualization of the macroscopic structure of hyaline cartilage with MR imaging.

    Science.gov (United States)

    Goodwin, D W

    2001-12-01

    The extracellular matrix of any tissue, including hyaline cartilage, has a structure that allows it to meet the physical demands placed upon that tissue. Accordingly, the structure of hyaline cartilage is not uniform. There is considerable variation from one joint to the next and even within a particular joint surface, probably reflecting a joint-specific architecture. This structure has a strong influence on T(2) relaxation. The relationship between T2 and matrix curvature relative to the main magnetic field (B(0)) provides tissue contrast. Images obtained with adequate resolution can exploit this contrast and demonstrate the structure of cartilage. Magnetic resonance imaging is thus capable of providing a detailed description of the structure of joint surfaces, information that is difficult to obtain even with histologic techniques.

  20. Basis Light-Front Quantization: Recent Progress and Future Prospects

    Science.gov (United States)

    Vary, James P.; Adhikari, Lekha; Chen, Guangyao; Li, Yang; Maris, Pieter; Zhao, Xingbo

    2016-08-01

    Light-front Hamiltonian field theory has advanced to the stage of becoming a viable non-perturbative method for solving forefront problems in strong interaction physics. Physics drivers include hadron mass spectroscopy, generalized parton distribution functions, spin structures of the hadrons, inelastic structure functions, hadronization, particle production by strong external time-dependent fields in relativistic heavy ion collisions, and many more. We review selected recent results and future prospects with basis light-front quantization that include fermion-antifermion bound states in QCD, fermion motion in a strong time-dependent external field and a novel non-perturbative renormalization scheme.

  1. Overtopping of Rubble Mound Breakwaters with Front Reservoir

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke

    2007-01-01

    The design and performance of breakwaters with front reservoir are discussed on the basis of physical 2-D model tests with a number of cross sections, in which vertopping discharge and spatial distribution, wave forces on inner parapet walls, and stability of reservoir armour were studied....... The sensitivity of these quantities to the width of the reservoir is discussed. It is demonstrated that front reservoir solutions are more economical than conventional cross section solutions, such as bermed structures and mild slope structures, in cases where low crests and small overtopping discharges...

  2. Analytical and numerical modeling of front propagation and interaction of fronts in nonlinear thermoviscous

    DEFF Research Database (Denmark)

    Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

    2008-01-01

    A wave equation, that governs nite amplitude acoustic disturbances in a thermoviscous Newtonian fluid, and includes nonlinear terms up to second order, is proposed. In contrast to the model known as the Kuznetsov equation, the proposed nonlinear wave equation preserves the Hamiltonian structure...... of the fundamental fluid dynamical equations in the non-dissipative limit. An exact traveling front solution is obtained from a generalized traveling wave assumption. This solution is, in an overall sense, equivalent to the Taylor shock solution of the Burgers equation. However, in contrast to the Burgers equation...... with respect to the fluid ahead of it, and subsonic speed with respect to the fluid behind it, similarly to the fluid dynamical shock. Linear stability analysis reveals that the front is stable when the acoustic pressure belongs to a critical interval, and is otherwise unstable. These results are veried...

  3. Weather fronts and acute myocardial infarction

    Science.gov (United States)

    Kveton, Vit

    1991-03-01

    Some methodological aspects are discussed of the investigation of acute infarct myocarditis (AIM) in relation to weather fronts. Results of a new method of analysis are given. Data were analysed from about the hour of the onset of symptoms, and led to the diagnosis of AIM either immediately or within a few hours or days (3019 cases observed over 4.5 years during 1982 1986 in Plzen, Czechoslovakia). Weather classification was based on three factors (the type of the foregoing front, the type of the subsequent front, the time section of the time interval demarcated by the passage of the surfaces of the fronts). AIM occurrence increased in particular types of weather fronts: (i) by 30% during 7 12 h after a warm front, if the time span between fronts exceeded 24 h; (ii) by 10% in time at least 36 h distant from the foregoing cold or occlusion front and from the succeeding warm or occlusion front; (iii) by 20% during 0 2 h before the passage of the front, provided the foregoing front was not warm and the interval between fronts exceeded 5 h. AIM occurrence decreased by 15% 20% for time span between fronts > 24 h at times 6 11, 6 23 and 6 35 h before a coming warm or occlusion front (for interfrontal intervals 25 48, 49 72 and possibly > 72 h), and also at 12 23 and possibly 12 35 h before a cold front (for intervals 49 72 and possibly > 72 h), if the foregoing front was cold or an occlusion front.

  4. Visualizing impact structures using high-resolution LiDAR-derived DEMs: A case study of two structures in Missouri

    Science.gov (United States)

    Finn, Michael P.; Krizanich, Gary W.; Evans, Kevin R.; Cox, Melissa R.; Yamamoto, Kristina H.

    2015-01-01

    Evidence suggests that a crypto-explosive hypothesis and a meteorite impact hypothesis may be partly correct in explaining several anomalous geological features in the middle of the United States. We used a primary geographic information science (GIScience) technique of creating a digital elevation model (DEM) of two of these features that occur in Missouri. The DEMs were derived from airborne light detection and ranging, or LiDAR. Using these DEMs, we characterized the Crooked Creek structure in southern Crawford County and the Weaubleau structure in southeastern St. Clair County, Missouri. The mensuration and study of exposed and buried impact craters implies that the craters may have intrinsic dimensions which could only be produced by collision. The results show elevations varying between 276 and 348 m for Crooked Creek and between 220 and 290 m for Weaubleau structure. These new high- resolution DEMs are accurate enough to allow for precise measurements and better interpretations of geological structures, particularly jointing in the carbonate rocks, and they show greater definition of the central uplift area in the Weaubleau structure than publicly available DEMs.

  5. Visual PEF Reader - VIPER

    Science.gov (United States)

    Luo, Victor; Khanampornpan, Teerapat; Boehmer, Rudy A.; Kim, Rachel Y.

    2011-01-01

    This software graphically displays all pertinent information from a Predicted Events File (PEF) using the Java Swing framework, which allows for multi-platform support. The PEF is hard to weed through when looking for specific information and it is a desire for the MRO (Mars Reconn aissance Orbiter) Mission Planning & Sequencing Team (MPST) to have a different way to visualize the data. This tool will provide the team with a visual way of reviewing and error-checking the sequence product. The front end of the tool contains much of the aesthetically appealing material for viewing. The time stamp is displayed in the top left corner, and highlighted details are displayed in the bottom left corner. The time bar stretches along the top of the window, and the rest of the space is allotted for blocks and step functions. A preferences window is used to control the layout of the sections along with the ability to choose color and size of the blocks. Double-clicking on a block will show information contained within the block. Zooming into a certain level will graphically display that information as an overlay on the block itself. Other functions include using hotkeys to navigate, an option to jump to a specific time, enabling a vertical line, and double-clicking to zoom in/out. The back end involves a configuration file that allows a more experienced user to pre-define the structure of a block, a single event, or a step function. The individual will have to determine what information is important within each block and what actually defines the beginning and end of a block. This gives the user much more flexibility in terms of what the tool is searching for. In addition to the configurability, all the settings in the preferences window are saved in the configuration file as well

  6. Online State-Based Structured SVM Combined With Incremental PCA for Robust Visual Tracking.

    Science.gov (United States)

    Yin, Yingjie; Xu, De; Wang, Xingang; Bai, Mingran

    2015-09-01

    In this paper, we propose a robust state-based structured support vector machine (SVM) tracking algorithm combined with incremental principal component analysis (PCA). Different from the current structured SVM for tracking, our method directly learns and predicts the object's states and not the 2-D translation transformation during tracking. We define the object's virtual state to combine the state-based structured SVM and incremental PCA. The virtual state is considered as the most confident state of the object in every frame. The incremental PCA is used to update the virtual feature vector corresponding to the virtual state and the principal subspace of the object's feature vectors. In order to improve the accuracy of the prediction, all the feature vectors are projected onto the principal subspace in the learning and prediction process of the state-based structured SVM. Experimental results on several challenging video sequences validate the effectiveness and robustness of our approach.

  7. Correlation between visual field index and other functional and structural measures in glaucoma patients and suspects

    Directory of Open Access Journals (Sweden)

    Natalia A Iutaka

    2017-01-01

    Conclusion: VFI showed a strong correlation with MD and PSD but demonstrated a weak correlation with structural measures. It can possibly be used as a marker for functional impairment severity in patients with glaucoma.

  8. Visual Evaluation of the Morphologic Structure of Nonwovens Using Image Analysis and Fractal Geometry

    Institute of Scientific and Technical Information of China (English)

    杨旭红; 李栋高

    2004-01-01

    Nonwovens are fiber materials which are based on nonwoven technologies. For the complexity and randomness of nonwovens morphologic structures, it is difficult to express them effectively using classical method. Fractal geometry gives us a new idea and a powerful tool to study on irregularity of geometric objects. Therefore, we studied on the pore size, pore shape, pore size distribution and fiber orientation distribution of real nonwovens using fractal geometry combined with computer image analysis to evaluate nonwovens' morphologic structures.

  9. Summarizing and Visualizing Structural Changes during the Evolution of Biomedical Ontologies Using a Diff Abstraction Network

    OpenAIRE

    Ochs, Christopher; Perl, Yehoshua; Geller, James; Haendel, Melissa; Brush, Matthew; Arabandi, Sivaram; Tu, Samson

    2015-01-01

    Biomedical ontologies are a critical component in biomedical research and practice. As an ontology evolves, its structure and content change in response to additions, deletions and updates. When editing a biomedical ontology, small local updates may affect large portions of the ontology, leading to unintended and potentially erroneous changes. Such unwanted side effects often go unnoticed since biomedical ontologies are large and complex knowledge structures. Abstraction networks, which provi...

  10. Inspection of Pole-Like Structures Using a Visual-Inertial Aided VTOL Platform with Shared Autonomy

    Directory of Open Access Journals (Sweden)

    Inkyu Sa

    2015-09-01

    Full Text Available This paper presents an algorithm and a system for vertical infrastructure inspection using a vertical take-off and landing (VTOL unmanned aerial vehicle and shared autonomy. Inspecting vertical structures such as light and power distribution poles is a difficult task that is time-consuming, dangerous and expensive. Recently, micro VTOL platforms (i.e., quad-, hexa- and octa-rotors have been rapidly gaining interest in research, military and even public domains. The unmanned, low-cost and VTOL properties of these platforms make them ideal for situations where inspection would otherwise be time-consuming and/or hazardous to humans. There are, however, challenges involved with developing such an inspection system, for example flying in close proximity to a target while maintaining a fixed stand-off distance from it, being immune to wind gusts and exchanging useful information with the remote user. To overcome these challenges, we require accurate and high-update rate state estimation and high performance controllers to be implemented onboard the vehicle. Ease of control and a live video feed are required for the human operator. We demonstrate a VTOL platform that can operate at close-quarters, whilst maintaining a safe stand-off distance and rejecting environmental disturbances. Two approaches are presented: Position-Based Visual Servoing (PBVS using an Extended Kalman Filter (EKF and estimator-free Image-Based Visual Servoing (IBVS. Both use monocular visual, inertia, and sonar data, allowing the approaches to be applied for indoor or GPS-impaired environments. We extensively compare the performances of PBVS and IBVS in terms of accuracy, robustness and computational costs. Results from simulations Sensors 2015, 15 22004 and indoor/outdoor (day and night flight experiments demonstrate the system is able to successfully inspect and circumnavigate a vertical pole.

  11. The visual framing of graphics when used in preventative health digital news packages: exploring the use of a narrative structure as the message infrastructure.

    Science.gov (United States)

    Sontag, Jennah M; Barnes, Spencer R

    2017-09-26

    Visual framing can improve health-message effectiveness. Narrative structure provides a template needed for determining how to frame visuals to maximise message effectiveness. Participants (N = 190) were assigned to a message condition determined by segments (establisher, initial, peak), graphic (static, animated) and cancer (lung, melanoma). ANOVAs revealed that melanoma was more believable than lung cancer with static graphics at the establisher and peak; narratives were more believable with animated graphics at the peak segment; melanoma elicited greater positive attitudes; graphics in the peak influenced greatest intentions. Animated graphics visually framed to emphasise information at the establisher and peak segments suggest maximum effectiveness.

  12. FRIB Front End Design Status

    CERN Document Server

    Pozdeyev, E; Machicoane, G; Morgan, G; Rao, X; Zhao, Q; Stovall, J; Vorozhtsov, S; Sun, L

    2013-01-01

    The Facility for Rare Isotope Beams (FRIB) will provide a wide range of primary ion beams for nuclear physics research with rare isotope beams. The FRIB SRF linac will be capable of accelerating medium and heavy ion beams to energies beyond 200 MeV/u with a power of 400 kW on the fragmentation target. This paper presents the status of the FRIB Front End designed to produce uranium and other medium and heavy mass ion beams at world-record intensities. The paper describes the FRIB high performance superconducting ECR ion source, the beam transport designed to transport two-charge state ion beams and prepare them for the injection in to the SRF linac, and the design of a 4-vane 80.5 MHz RFQ. The paper also describes the integration of the front end with other accelerator and experimental systems.

  13. Monitoring of Structures and Mechanical Systems Using Virtual Visual Sensors for Video Analysis: Fundamental Concept and Proof of Feasibility

    Directory of Open Access Journals (Sweden)

    Thomas Schumacher

    2013-12-01

    Full Text Available Structural health monitoring (SHM has become a viable tool to provide owners of structures and mechanical systems with quantitative and objective data for maintenance and repair. Traditionally, discrete contact sensors such as strain gages or accelerometers have been used for SHM. However, distributed remote sensors could be advantageous since they don’t require cabling and can cover an area rather than a limited number of discrete points. Along this line we propose a novel monitoring methodology based on video analysis. By employing commercially available digital cameras combined with efficient signal processing methods we can measure and compute the fundamental frequency of vibration of structural systems. The basic concept is that small changes in the intensity value of a monitored pixel with fixed coordinates caused by the vibration of structures can be captured by employing techniques such as the Fast Fourier Transform (FFT. In this paper we introduce the basic concept and mathematical theory of this proposed so-called virtual visual sensor (VVS, we present a set of initial laboratory experiments to demonstrate the accuracy of this approach, and provide a practical in-service monitoring example of an in-service bridge. Finally, we discuss further work to improve the current methodology.

  14. Visual signal detection in structured backgrounds. I. Effect of number of possible spatial locations and signal contrast.

    Science.gov (United States)

    Eckstein, M P; Whiting, J S

    1996-09-01

    Several studies have investigated the effect of signal location uncertainty on the detectability of simple visual signals in uncorrelated Gaussian noise with a deterministic background. For this case, human performance in locating a signal in a forced-choice experiment has been successfully predicted for 2-1800 alternative locations with the use of signal detection theory and the usual assumption that the observer's internal response is Gaussian distributed. Gaussian uncorrelated noise is far from realistic medical image noise, which includes not only fluctuations in intensity of quantum origin but also other anatomical objects lying in the x-ray path (structured backgrounds). Our goal is to determine whether signal detection theory with the Gaussian assumption is adequate for the case of structured backgrounds, or whether other more complex models need to be developed to predict human performance as a function of the number of possible signal locations in structured backgrounds. We present experimental data suggesting that an assumed Gaussian internal response accurately predicts the decrease in observer performance as the number of alternative locations is increased. The one exception is a lower-than-predicted performance for the detection of low-contrast signals for two alternative locations. Performance as measured by the index of detectability d' is also found to be linear with signal contrast. Together these findings extend the applicability of signal detection theory with Gaussian internal response functions to the case of complex structured backgrounds.

  15. Light-Front Holography, Color Confinement, and Supersymmetric Features of QCD

    CERN Document Server

    Brodsky, Stanley J

    2016-01-01

    Light-Front Quantization provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic light-front wavefunctions. One obtains new insights into the hadronic spectrum, light-front wavefunctions, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography -- the duality between the front form and AdS$_5$, the space of isometries of the conformal group. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons of the same parity. The mass scale $\\kappa$ underlying confinement and hadron masses can be connected to the parameter $\\Lambda_{\\overline {MS}}$ in the QCD running coupling by matching the nonperturbative dynamics, as described by the effective conformal theory mapped to the light-front and its embedding in AdS space, to the perturbative QCD regime. The...

  16. Disk Instabilities and Cooling Fronts

    CERN Document Server

    Vishniac, E T

    1998-01-01

    Accretion disk outbursts, and their subsequent decline, offer a unique opportunity to constrain the physics of angular momentum transport in hot accretion disks. Recent work has centered on the claim by Cannizzo et al. that the exponential decay of luminosity following an outburst in black hole accretion disk systems is only consistent with a particular form for the dimensionless viscosity, $\\alpha=35(c_s/r\\Omega)^{3/2}$. This result can be understood in terms of a simple model of the evolution of cooling fronts in accretion disks. In particular, the cooling front speed during decline is $\\sim cooling front, and the exact value of $n$ depends on the hot state opacity, (although generally $n\\approx 1/2$). Setting this speed proportional to $r$ constrains the functional form of $\\alpha$ in the hot phase of the disk, which sets it apart from previous arguments based on the relative durations of outburst and quiescence. However, it remains uncertain how well we know the exponent $n$. In addition, more work is nee...

  17. Community-analyzer: a platform for visualizing and comparing microbial community structure across microbiomes.

    Science.gov (United States)

    Kuntal, Bhusan K; Ghosh, Tarini Shankar; Mande, Sharmila S

    2013-10-01

    A key goal in comparative metagenomics is to identify microbial group(s) which are responsible for conferring specific characteristics to a given environment. These characteristics are the result of the inter-microbial interactions between the resident microbial groups. We present a new GUI-based comparative metagenomic analysis application called Community-Analyzer which implements a correlation-based graph layout algorithm that not only facilitates a quick visualization of the differences in the analyzed microbial communities (in terms of their taxonomic composition), but also provides insights into the inherent inter-microbial interactions occurring therein. Notably, this layout algorithm also enables grouping of the metagenomes based on the probable inter-microbial interaction patterns rather than simply comparing abundance values of various taxonomic groups. In addition, the tool implements several interactive GUI-based functionalities that enable users to perform standard comparative analyses across microbiomes. For academic and non-profit users, the Community-Analyzer is currently available for download from: http://metagenomics.atc.tcs.com/Community_Analyzer/.

  18. Structural and neurochemical correlates of individual differences in gamma frequency oscillations in human visual cortex.

    Science.gov (United States)

    Robson, Siân E; Muthukumarawswamy, Suresh D; John Evans, C; Shaw, Alexander; Brealy, Jennifer; Davis, Brittany; McNamara, Grainne; Perry, Gavin; Singh, Krish D

    2015-10-01

    Neuronal oscillations in the gamma frequency range play an important role in stimulus processing in the brain. The frequency of these oscillations can vary widely between participants and is strongly genetically determined, but the cause of this variability is not understood. Previous studies have reported correlations between individual differences in gamma frequency and the concentration of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), as well as with age and primary visual cortex (V1) area and thickness. This study assessed the relationships between all of these variables in the same group of participants. There were no significant correlations between gamma frequency and GABA+ concentration, V1 area or V1 thickness, although the relationship with GABA+/Cr approached significance. Considering age as a covariate further reduced the strength of all correlations and, in an additional dataset with a larger age range, gamma frequency was strongly inversely correlated with age but not V1 thickness or area, suggesting that age modulates gamma frequency via an additional, as yet unknown, mechanism. Consistent with other recent studies, these findings do not demonstrate a clear relationship between gamma frequency and GABA+ concentration. Further investigation of additional variables and the interactions between them will be necessary in order to more accurately determine predictors of the frequency of gamma oscillations. © 2015 Anatomical Society.

  19. Construction and visualization of high-resolution three-dimensional anatomical structure datasets for Chinese digital human

    Institute of Scientific and Technical Information of China (English)

    LI AnAn; LIU Qian; ZENG ShaoQun; TANG Lei; ZHONG ShiZhen; LUO QingMing

    2008-01-01

    The objective of the China Digital Human Project (CDH) is to digitize and visualize the anatomical structures of human body. In the project, a database with information of morphology, physical charac-teristics and physiological function will be constructed. The raw data of CDH which was completed in the Southern Medical University is employed. In Huazhong University of Science and Technology (HUST), the frozen section images are preprocessed, segmented, labeled in accordance with the major organs and tissues of human beings, and reconstructed into three-dimensional (3D) models in parallel on high performance computing clusters (HPC). Some visualization software for 2D atlas and 3D mod-els are developed based on the new dataset with high resolution (0.1 mm×0.1 mm×0.2 mm). In order to share, release and popularize the above work, a website (www.vch.org.cn) is online. The dataset is one of the most important parts in the national information database and the medical infrastructure.

  20. Four-dimensional visualization of a small-scale flame based on deflection tomography

    Science.gov (United States)

    Zhang, Bin; Liu, Zhigang; Zhao, Minmin

    2016-11-01

    Optical computed tomography is an important technique in the visualization and diagnosis of various flow fields. A small-scale diffusion flame was visualized using deflection tomography. A projection sampling system was proposed for deflection tomography to obtain deflectograms with a pair of gratings. Wave-front retrieval was employed for processing the deflectograms to obtain the deflection angles of the rays. This two-dimensional data extraction method expanded the application of deflection tomography and was suitable for the projection extraction of small-scale combustion. Deflection angle revision reconstruction algorithm was used to reconstruct the temperature distributions in 10 cross sections for each deflectogram in different instants. The flow structure was reconstructed using a visualization toolkit equipped with the marching cube and ray casting algorithms. The performed experiments demonstrated the three-dimensional dynamic visualization of temperature distributions and the flame structures of small-scale diffusion combustion.

  1. Visualization and research of gas-liquid two phase flow structures in cylindrical channel

    Directory of Open Access Journals (Sweden)

    Stefański Sebastian

    2017-01-01

    Full Text Available Two-phase flows are commonly found in many industries, especially in systems, where efficient and correct functioning depend on specific values of flow parameters. In thermal engineering and chemical technology the most popular types of two-phase mixture are gas-liquid or liquid-vapour mixtures. Bubbles can create in flow different structures and determine diverse properties of flow (velocity of phase, void fraction, fluctuations of pressure, pipe vibrations, etc.. That type of flow is difficult to observe, especially in liquid-vapour mixture, where vapour is being made by heating the medium. Production of vapour and nucleation process are very complicated issues, which are important part of two-phase flow phenomenon. Gas-liquid flow structures were observed and described with figures, but type of structure depends on many parameters. Authors of this paper made an attempt to simulate gas-liquid flow with air and water. In the paper there was presented specific test stand built to observe two-phase flow structures, methodology of experiment and conditions which were maintained during observation. The paper presents also the structures which were observed and the analysis of results with reference to theoretical models and diagrams available in literature.

  2. Fluctuation charge effects in ionization fronts

    Energy Technology Data Exchange (ETDEWEB)

    Arrayas, Manuel; Trueba, Jose L [Area de Electromagnetismo, Universidad Rey Juan Carlos, Camino del Molino s/n, 28943 Fuenlabrada, Madrid (Spain); Baltanas, J P [Departamento de Fisica Aplicada II, Universidad de Sevilla, Av. Reina Mercedes 2, 41012 Sevilla (Spain)

    2008-05-21

    In this paper, we study the effects of charge fluctuations on the propagation of both negative and positive ionization fronts in streamer discharges. We show that fronts accelerate when random charge creation events are present. This effect might play a similar role to photoionization in order to make the front move faster.

  3. [New method for analysis and visualization of the fine temporal structure of the transient evoked otoacoustic emission signal].

    Science.gov (United States)

    Belov, O A; Alekseeva, N N; Tavartkiladze, G A

    2014-01-01

    We have developed the new method for the analysis and visualization of the fine temporal structure of the transient evoked otoacoustic emission signal. The method consists of the presentation of the signal in the form of a set of tone components with a rapidly changing amplitude and relatively stable frequency. It is based on the combination of three spectrograms differing in frequency and temporal resolution by means of fuzzy logic amplitude estimation with subsequent frequency refining with the use of the least square procedure, reduction of the number of the insignificant components, and final re-ordering of the results for the simplification of further data processing. The new method was named Pitch Envelope Analysis (PEA). For data representation, a new type of diagram named componentogram was designed. The proposed method can be used for the real time processing of the continuous data stream especially for speech processing.

  4. A new methodology for the quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding (MBES)

    Science.gov (United States)

    Best, Jim; Simmons, Stephen; Parsons, Daniel; Oberg, Kevin; Czuba, Jonathan; Malzone, Chris

    2010-03-01

    In order to investigate the interactions between turbulence and suspended sediment transport in natural aqueous environments, we ideally require a technique that allows simultaneous measurement of fluid velocity and sediment concentration for the whole flow field. Here, we report on development of a methodology using the water column acoustic backscatter signal from a multibeam echo sounder to simultaneously quantify flow velocities and sediment concentrations. The application of this new technique is illustrated with reference to flow over the leeside of an alluvial sand dune, which allows, for the first time in a field study, quantitative visualization of large-scale, whole flow field, turbulent coherent flow structures associated with the dune leeside that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows.

  5. Ancestral informative marker selection and population structure visualization using sparse Laplacian eigenfunctions.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference.

  6. Mitochondrial dynamics in visual cortex are limited in vivo and not affected by axonal structural plasticity.

    NARCIS (Netherlands)

    Smit-Rigter, L.A.; Rajendran, Rajeev; Silva, Catia A.P.; Spierenburg, Liselot; Groeneweg, Femke; Ruimschotel, E.; Van Versendaal, D.; van der Togt, C.; Eysel, Ulf T.; Heimel, J.A.; Lohmann, C.; Levelt, C.N.

    2016-01-01

    Mitochondria buffer intracellular Ca2+ and provide energy [1]. Because synaptic structures with high Ca2+ buffering [2–4] or energy demand [5] are often localized far away from the soma, mitochondria are actively transported to these sites [6–11]. Also, the removal and degradation of mitochondria ar

  7. Visualizing the Structure of Medical Informatics Using Term Co-Occurrence Analysis.

    Science.gov (United States)

    Morris, Theodore Allan

    2000-01-01

    Examines the structure of medical informatics and the relationship between biomedicine and information science and information technology. Uses co-occurrence analysis of subject headings assigned to items indexed for MEDLINE as well as multidimensional scaling to show seven to eight broad multidisciplinary subject clusters. (Contains 28…

  8. Visualizing the Structure of Medical Informatics Using Term Co-Occurrence Analysis: II. INSPEC Perspective.

    Science.gov (United States)

    Morris, Theodore

    2001-01-01

    Term co-occurrence analysis of INSPEC classification codes and thesaurus terms used to index Medical Informatics literature reveals an information science and technology perspective on the field, to accompany the biomedical perspective previously reported. This study continues the search for a better understanding of the structure of Medical…

  9. Robust Generation of Dynamic Data Structure Visualizations with Multiple Interaction Approaches

    Science.gov (United States)

    Cross, James H., II; Hendrix, T. Dean; Umphress, David A.; Barowski, Larry A.; Jain, Jhilmil; Montgomery, Lacey N.

    2009-01-01

    jGRASP has three integrated approaches for interacting with its dynamic viewers for data structures: debugger, workbench, and text-based interactions that allow individual Java statements and expressions to be executed/evaluated. These approaches can be used together to provide a complementary set of interactions with the dynamic viewers. Data…

  10. Spatial Visualization Tasks to Support Students' Spatial Structuring in Learning Volume Measurement

    Science.gov (United States)

    Revina, Shintia; Zulkardi; Darmawijoyo; van Galen, Frans

    2011-01-01

    Many prior researches found that most of students in grade five tended to have difficulty in fully grasping the concept of volume measurement because they have to build their competence in spatial structuring. The unit of volume "packing" measurement must be integrated and coordinated in three-dimension. On the other hand, it is revealed…

  11. Rapid protocol for visualization of rust fungi structures using fluorochrome Uvitex 2B.

    Science.gov (United States)

    Dugyala, Sheshanka; Borowicz, Pawel; Acevedo, Maricelis

    2015-01-01

    Histological examination using fluorochromes is one of the standard methods for observation of microorganisms in tissues and other compartments. In the study of fungi, especially those that cannot be cultured in axenic media such as biotrophic fungi, histological examination of processes associated with the fungal growth, differentiation, infection and other cellular functions can lead to the better understanding of host-parasite interactions. Fluorescence microscopy coupled with Fluorochrome Uvitex 2B have been extensively utilized to study rust fungi structures and host-pathogen interactions. In this study, we report development of a rapid staining protocol of the rust fungus Puccinia triticina using fluorochrome Uvitex 2B. The newly developed rapid procedure was compared with a standard staining technique to observe in planta fungal infection structures development during the wheat-Puccinia triticina interaction. While significantly reducing the time for staining, the rapid protocol described here was equally efficient or better compared to standard procedure in detecting fungal infection structures using Uvitex 2B. In the rapid staining procedure, pre-heating of the stain increased efficiency to detect all the infection structures including haustoria with highly reduced background noise from plant tissue. This staining process described here is simple and quick. It can be completed in 4 h, which is of 6 times faster than the standard Uvitex 2B staining procedure.

  12. RepeatsDB 2.0: improved annotation, classification, search and visualization of repeat protein structures

    Science.gov (United States)

    Paladin, Lisanna; Hirsh, Layla; Piovesan, Damiano; Andrade-Navarro, Miguel A.; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2017-01-01

    RepeatsDB 2.0 (URL: http://repeatsdb.bio.unipd.it/) is an update of the database of annotated tandem repeat protein structures. Repeat proteins are a widespread class of non-globular proteins carrying heterogeneous functions involved in several diseases. Here we provide a new version of RepeatsDB with an improved classification schema including high quality annotations for ∼5400 protein structures. RepeatsDB 2.0 features information on start and end positions for the repeat regions and units for all entries. The extensive growth of repeat unit characterization was possible by applying the novel ReUPred annotation method over the entire Protein Data Bank, with data quality is guaranteed by an extensive manual validation for >60% of the entries. The updated web interface includes a new search engine for complex queries and a fully re-designed entry page for a better overview of structural data. It is now possible to compare unit positions, together with secondary structure, fold information and Pfam domains. Moreover, a new classification level has been introduced on top of the existing scheme as an independent layer for sequence similarity relationships at 40%, 60% and 90% identity. PMID:27899671

  13. Ultrasonic thickness structural health monitoring photoelastic visualization and measurement accuracy for internal pipe corrosion

    Science.gov (United States)

    Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.

    2015-03-01

    Oil refinery production of fuels is becoming more challenging as a result of the changing world supply of crude oil towards properties of higher density, higher sulfur concentration, and higher acidity. One such production challenge is an increased risk of naphthenic acid corrosion that can result in various surface degradation profiles of uniform corrosion, non-uniform corrosion, and localized pitting in piping systems at temperatures between 150°C and 400°C. The irregular internal surface topology and high external surface temperature leads to a challenging in-service monitoring application for accurate pipe wall thickness measurements. Improved measurement technology is needed to continuously profile the local minimum thickness points of a non-uniformly corroding surface. The measurement accuracy and precision must be sufficient to provide a better understanding of the integrity risk associated with refining crude oils of higher acid concentration. This paper discusses potential technologies for measuring localized internal corrosion in high temperature steel piping and describes the approach under investigation to apply flexible ultrasonic thin-film piezoelectric transducer arrays fabricated by the sol-gel manufacturing process. Next, the elastic wave beam profile of a sol-gel transducer is characterized via photoelastic visualization. Finally, the variables that impact measurement accuracy and precision are discussed and a maximum likelihood statistical method is presented and demonstrated to quantify the measurement accuracy and precision of various time-of-flight thickness calculation methods in an ideal environment. The statistical method results in confidence values analogous to the a90 and a90/95 terminology used in Probability-of-Detection (POD) assessments.

  14. EEG and Eye Tracking Signatures of Target Encoding during Structured Visual Search.

    Science.gov (United States)

    Brouwer, Anne-Marie; Hogervorst, Maarten A; Oudejans, Bob; Ries, Anthony J; Touryan, Jonathan

    2017-01-01

    EEG and eye tracking variables are potential sources of information about the underlying processes of target detection and storage during visual search. Fixation duration, pupil size and event related potentials (ERPs) locked to the onset of fixation or saccade (saccade-related potentials, SRPs) have been reported to differ dependent on whether a target or a non-target is currently fixated. Here we focus on the question of whether these variables also differ between targets that are subsequently reported (hits) and targets that are not (misses). Observers were asked to scan 15 locations that were consecutively highlighted for 1 s in pseudo-random order. Highlighted locations displayed either a target or a non-target stimulus with two, three or four targets per trial. After scanning, participants indicated which locations had displayed a target. To induce memory encoding failures, participants concurrently performed an aurally presented math task (high load condition). In a low load condition, participants ignored the math task. As expected, more targets were missed in the high compared with the low load condition. For both conditions, eye tracking features distinguished better between hits and misses than between targets and non-targets (with larger pupil size and shorter fixations for missed compared with correctly encoded targets). In contrast, SRP features distinguished better between targets and non-targets than between hits and misses (with average SRPs showing larger P300 waveforms for targets than for non-targets). Single trial classification results were consistent with these averages. This work suggests complementary contributions of eye and EEG measures in potential applications to support search and detect tasks. SRPs may be useful to monitor what objects are relevant to an observer, and eye variables may indicate whether the observer should be reminded of them later.

  15. Inferring clonal structure in HTLV-1-infected individuals: towards bridging the gap between analysis and visualization.

    Science.gov (United States)

    Farmanbar, Amir; Firouzi, Sanaz; Makałowski, Wojciech; Iwanaga, Masako; Uchimaru, Kaoru; Utsunomiya, Atae; Watanabe, Toshiki; Nakai, Kenta

    2017-07-11

    Human T cell leukemia virus type 1 (HTLV-1) causes adult T cell leukemia (ATL) in a proportion of infected individuals after a long latency period. Development of ATL is a multistep clonal process that can be investigated by monitoring the clonal expansion of HTLV-1-infected cells by isolation of provirus integration sites. The clonal composition (size, number, and combinations of clones) during the latency period in a given infected individual has not been clearly elucidated. We used high-throughput sequencing technology coupled with a tag system for isolating integration sites and measuring clone sizes from 60 clinical samples. We assessed the role of clonality and clone size dynamics in ATL onset by modeling data from high-throughput monitoring of HTLV-1 integration sites using single- and multiple-time-point samples. From four size categories analyzed, we found that big clones (B; 513-2048 infected cells) and very big clones (VB; >2048 infected cells) had prognostic value. No sample harbored two or more VB clones or three or more B clones. We examined the role of clone size, clone combination, and the number of integration sites in the prognosis of infected individuals. We found a moderate reverse correlation between the total number of clones and the size of the largest clone. We devised a data-driven model that allows intuitive representation of clonal composition. This integration site-based clonality tree model represents the complexity of clonality and provides a global view of clonality data that facilitates the analysis, interpretation, understanding, and visualization of the behavior of clones on inter- and intra-individual scales. It is fully data-driven, intuitively depicts the clonality patterns of HTLV-1-infected individuals and can assist in early risk assessment of ATL onset by reflecting the prognosis of infected individuals. This model should assist in assimilating information on clonal composition and understanding clonal expansion in HTLV-1

  16. Identification and visualization of the intellectual structure and the main research lines in nanoscience and nanotechnology at the worldwide level

    Science.gov (United States)

    Muñoz-Écija, Teresa; Vargas-Quesada, Benjamín; Chinchilla-Rodríguez, Zaida

    2017-02-01

    The aim of this paper is to make manifest the intellectual and cognitive structure of nanoscience and nanotechnology (NST) by means of visualization techniques. To this end, we used data from the Web of Science (WoS), delimiting the data to the category NST during the period of 2000-2013, retrieving a total of 198,275 documents. Through direct author citation of these works, we identified their origins and the seminal papers, and through word co-occurrence extracted from the titles and abstracts, the main lines of research were identified. In view of both structures, we may affirm that NST is a young scientific discipline in constant expansion, needing time to establish its foundations but showing a strongly interdisciplinary character; its development is furthermore dependent upon knowledge from other disciplines, such as physics, chemistry, or material sciences. We believe that this information may be very useful for the NST scientific community, as it reflects a large-scale analysis of the research lines of NST and how research has changed over time in the diverse areas of NST. This study is moreover intended to offer a useful tool for the NST scientific community, revealing at a glance the main research lines and landmark papers. Finally, the methodology used in this study can be replicated in any other field of science to explore its intellectual and cognitive structure.

  17. MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

    1993-02-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

  18. Identification and visualization of the intellectual structure and the main research lines in nanoscience and nanotechnology at the worldwide level.

    Science.gov (United States)

    Muñoz-Écija, Teresa; Vargas-Quesada, Benjamín; Chinchilla-Rodríguez, Zaida

    2017-01-01

    The aim of this paper is to make manifest the intellectual and cognitive structure of nanoscience and nanotechnology (NST) by means of visualization techniques. To this end, we used data from the Web of Science (WoS), delimiting the data to the category NST during the period of 2000-2013, retrieving a total of 198,275 documents. Through direct author citation of these works, we identified their origins and the seminal papers, and through word co-occurrence extracted from the titles and abstracts, the main lines of research were identified. In view of both structures, we may affirm that NST is a young scientific discipline in constant expansion, needing time to establish its foundations but showing a strongly interdisciplinary character; its development is furthermore dependent upon knowledge from other disciplines, such as physics, chemistry, or material sciences. We believe that this information may be very useful for the NST scientific community, as it reflects a large-scale analysis of the research lines of NST and how research has changed over time in the diverse areas of NST. This study is moreover intended to offer a useful tool for the NST scientific community, revealing at a glance the main research lines and landmark papers. Finally, the methodology used in this study can be replicated in any other field of science to explore its intellectual and cognitive structure.

  19. Visualization and quantification of whole rat heart laminar structure using high-spatial resolution contrast-enhanced MRI.

    Science.gov (United States)

    Gilbert, Stephen H; Benoist, David; Benson, Alan P; White, Ed; Tanner, Steven F; Holden, Arun V; Dobrzynski, Halina; Bernus, Olivier; Radjenovic, Aleksandra

    2012-01-01

    It has been shown by histology that cardiac myocytes are organized into laminae and this structure is important in function, both influencing the spread of electrical activation and enabling myocardial thickening in systole by laminar sliding. We have carried out high-spatial resolution three-dimensional MRI of the ventricular myolaminae of the entire volume of the isolated rat heart after contrast perfusion [dimeglumine gadopentate (Gd-DTPA)]. Four ex vivo rat hearts were perfused with Gd-DTPA and fixative and high-spatial resolution MRI was performed on a 9.4T MRI system. After MRI, cryosectioning followed by histology was performed. Images from MRI and histology were aligned, described, and quantitatively compared. In the three-dimensional MR images we directly show the presence of laminae and demonstrate that these are highly branching and are absent from much of the subepicardium. We visualized these MRI volumes to demonstrate laminar architecture and quantitatively demonstrated that the structural features observed are similar to those imaged in histology. We showed qualitatively and quantitatively that laminar architecture is similar in the four hearts. MRI can be used to image the laminar architecture of ex vivo hearts in three dimensions, and the images produced are qualitatively and quantitatively comparable with histology. We have demonstrated in the rat that: 1) laminar architecture is consistent between hearts; 2) myolaminae are absent from much of the subepicardium; and 3) although localized orthotropy is present throughout the myocardium, tracked myolaminae are branching structures and do not have a discrete identity.

  20. The Solid* toolset for software visual analytics of program structure and metrics comprehension : From research prototype to product

    NARCIS (Netherlands)

    Reniers, Dennie; Voinea, Lucian; Ersoy, Ozan; Telea, Alexandru

    2014-01-01

    Software visual analytics (SVA) tools combine static program analysis and fact extraction with information visualization to support program comprehension. However, building efficient and effective SVA tools is highly challenging, as it involves extensive software development in program analysis, gra

  1. Time-Gated Optical Projection Tomography Allows Visualization of Adult Zebrafish Internal Structures

    Science.gov (United States)

    Foglia, Efrem Alessandro; Pistocchi, Anna; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Cotelli, Franco

    2012-01-01

    Optical imaging through biological samples is compromised by tissue scattering and currently various approaches aim to overcome this limitation. In this paper we demonstrate that an all optical technique, based on non-linear upconversion of infrared ultrashort laser pulses and on multiple view acquisition, allows the reduction of scattering effects in tomographic imaging. This technique, namely Time-Gated Optical Projection Tomography (TGOPT), is used to reconstruct three dimensionally the internal structure of adult zebrafish without staining or clearing agents. This method extends the use of Optical Projection Tomography to optically diffusive samples yielding reconstructions with reduced artifacts, increased contrast and improved resolution with respect to those obtained with non-gated techniques. The paper shows that TGOPT is particularly suited for imaging the skeletal system and nervous structures of adult zebrafish. PMID:23185643

  2. Open, Cross Platform Chemistry Application Unifying Structure Manipulation, External Tools, Databases and Visualization

    Science.gov (United States)

    2014-05-30

    The rendering data structures, support classes, and code reside in a rendering library that depends upon OpenGL and GLEW, but remains independent of...requires integration with Qt in order to open up windows, handle user interaction, and perform other common tasks. This is implemented in a Qt OpenGL ...library that provides customized OpenGL render windows and related functionality. Finally, Distribution Statement A: Distribution is approved for public

  3. Fronts and strong currents of the upper southeast Indian Ocean

    Institute of Scientific and Technical Information of China (English)

    HE Zhigang; DONG Zhaoqian; YUAN Xiaojun

    2006-01-01

    Hydrographic data, ADCP velocity and sea level anomaly derived from the satellite altimeter have been jointly analyzed in the southeast Indian Ocean. Results show the locations and orientations of the major oceanic fronts as well as the characteristics of the currents within these fronts in the area. Double subtropical fronts are observed in the section along 120°E, which conflicts with the frontal structure frequently observed before-the North Subtropical Front (NSTF) and South Subtropical Front (SSTF) merge into a single STF between 110°~115°E. The Subantarctic Front (SAF), influenced by the out-of-phase double eddies, runs across 48°S three times between 120° and 127°E. The surface current within the SAF is strengthened up to 105.4 cm/s by the geostrophic effect of these eddies. Furthermore eddies may cause the strong current to split up into two branches within the SAF. The SAF and the primary polar front (PF1) can be identified individually in the ADCP data with a separation distance of about 0.3° at latitude between 140° and 145°E, although they cannot be identified separately in the low-resolution hydrographic data. The different thermohaline characteristics of Circumpolar Deep Water (CDW) and Modified Circumpolar Deep Water (MCDW) result in the formation of Southern Antarctic Circumpolar Current Front (SACCF) in the southeast Indian Ocean. It consistently turns northward along the east flank of the Kerguelen Plateau after it runs through the Princess Elizabeth Trough and turns southward sharply north of 60°S with a little seasonal variations. It is shown that the locations and orientations of the SAF, the primary PF and SACCF in the ACC of the southeast Indian Ocean can be identified more precisely by the current distribution derived from ADCP data than by hydrographic data, because these fronts are usually accompanied by strong currents. However, the locations and orientations of the STF and the secondary PF are more difficult to be identified

  4. Neural Signatures of Spatial Statistical Learning: Characterizing the Extraction of Structure from Complex Visual Scenes.

    Science.gov (United States)

    Karuza, Elisabeth A; Emberson, Lauren L; Roser, Matthew E; Cole, Daniel; Aslin, Richard N; Fiser, Jozsef

    2017-08-29

    Behavioral evidence has shown that humans automatically develop internal representations adapted to the temporal and spatial statistics of the environment. Building on prior fMRI studies that have focused on statistical learning of temporal sequences, we investigated the neural substrates and mechanisms underlying statistical learning from scenes with a structured spatial layout. Our goals were twofold: (1) to determine discrete brain regions in which degree of learning (i.e., behavioral performance) was a significant predictor of neural activity during acquisition of spatial regularities and (2) to examine how connectivity between this set of areas and the rest of the brain changed over the course of learning. Univariate activity analyses indicated a diffuse set of dorsal striatal and occipitoparietal activations correlated with individual differences in participants' ability to acquire the underlying spatial structure of the scenes. In addition, bilateral medial-temporal activation was linked to participants' behavioral performance, suggesting that spatial statistical learning recruits additional resources from the limbic system. Connectivity analyses examined, across the time course of learning, psychophysiological interactions with peak regions defined by the initial univariate analysis. Generally, we find that task-based connectivity with these regions was significantly greater in early relative to later periods of learning. Moreover, in certain cases, decreased task-based connectivity between time points was predicted by overall posttest performance. Results suggest a narrowing mechanism whereby the brain, confronted with a novel structured environment, initially boosts overall functional integration and then reduces interregional coupling over time.

  5. Hydrodynamic instabilities in an ablation front

    Energy Technology Data Exchange (ETDEWEB)

    Piriz, A R; Portugues, R F [E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2004-06-01

    The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved.

  6. Mechanical characterization of sawn timber for structural use, graded visually in accordance with Spanish standard UNE 56544

    Directory of Open Access Journals (Sweden)

    Fernández-Golfín, J. I.

    1998-12-01

    Full Text Available The employment of timber in structures in Spain was hurting of the nonexistence of accepted calculation procedures. The recent adoption and publication of the Eurocode 5 compels to the employment of the characteristic values of the material in the structural calculation by the method of the finite elements. This report sets forth the results of the experiments carried out at INIA's Forest Research Centre (CIFOR-INIA regarding the mechanical characterization of sawn timber of size 150x50x3.000 mm and the structural uses of "Pinus sylvestris, P. radiata and P. pinaster" from different Spanish provenances. The characteristic values and strength classes corresponding with the grades stated in the Spanish standard UNE 56544 are also provided. The report compares and analyses the results of these experiments, and presents the conclusions drawn from the different behaviour shown by the four species. An analysis of the Spanish standard for the visual grading of structural timber is carried out on the three species.

    El empleo de la madera en la construcción en España adolecía de la inexistencia de procedimientos de cálculo normalizados. La reciente adopción y publicación del Eurocódigo 5 obliga al empleo de los valores característicos del material en el cálculo estructural de la madera por el método de los elementos finitos. Se presentan los resultados de la caracterización mecánica de la madera aserrada de tamaño (150x50x3.000 mm y usos estructurales de "Pinus sylvestris, P. radiata y P. pinaster" de diferentes procedencias, llevada a cabo en el Centro de Investigación Forestal (CIFOR del INIA. Se aportan los valores característicos y clases de resistencia que corresponden a las clases de calidad definidas en la norma UNE 56544. Se efectúa una comparación y análisis de los resultados obtenidos, extrayendo conclusiones respecto del diferente comportamiento observado para las cuatro especies. Se analiza la adecuación de la

  7. Implications in the design of a method for visual grading and mechanical testing of hardwood structural timber for designation within the European strength classes

    Energy Technology Data Exchange (ETDEWEB)

    Riesgo-Munoz, G.; Remacha-Gete, A.; Pedras-Saavedra, F.

    2011-07-01

    The international strength class system (En 338:2003) is based on a testing standard (EN 408:2004) that is not easy to use with hardwoods, although some of this type of timber, such as European oak (Quercus robur L.), is highly appreciated for construction purposes. This study proposes specifications for sampling design, visual grading and mechanical testing of oak wood. With this aim, 27 adult oaks were felled and sawn into pieces. A sample of quarter-sawn planks was selected, then air-dried and planed to 50x100x2,000 mm. The beams were visually graded in accordance with ten standards, and were mechanically tested, at an average wood moisture content of 21%. The Spanish visual grading standard UNE 56544:2007 was the most effective for categorizing the pieces. According to this standard, 39% of the sampled beams were suitable for structural use. The mean value of modulus of elasticity (11,702 N mm{sup -}2) and characteristic density (714 Kg m{sup -}3) enable preliminary designation of the wood in visual grade ME-2, to European strength class D40. However, the bending strength was too low for inclusion of the timber in the European strength classes. Criteria are proposed for elaborating visual grading rules for oak wood and for structural beam testing in order to allocate oak visual strength grades into strength classes. (Author) 35 refs.

  8. Dissociable effects of natural image structure and color on LFP and spiking activity in the lateral prefrontal cortex and extrastriate visual area V4.

    Science.gov (United States)

    Liebe, Stefanie; Logothetis, Nikos K; Rainer, Gregor

    2011-07-13

    Visual perception is mediated by unique contributions of the numerous brain regions that constitute the visual system. We performed simultaneous recordings of local field potentials (LFPs) and single unit activity (SUA) in areas V4 and lateral prefrontal cortex to characterize their contribution to visual processing. Here, we trained monkeys to identify natural images at different degradation levels in a visual recognition task. We parametrically varied color and structural information of natural images while the animals were performing the task. We show that the visual-evoked potential (VEP) of the LFP in V4 is highly sensitive to color, whereas the VEP in prefrontal cortex predominantly depends on image structure. When examining the relationship between VEP and SUA, we found that stimulus sensitivity for SUA was well predicted by the VEP in PF cortex but not in V4. Our results first reveal a functional specialization in both areas at the level of the LFP and further suggest that the degree to which mesoscopic signals, such as the VEP, are representative of the underlying SUA neural processing may be brain region specific within the context of visual recognition.

  9. Visualization of the structures of the hepatitis C virus replication complex

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Shih-Ching [Graduate Institute of Molecular and Cellular Biology, Tzu Chi University, Hualien, Taiwan (China); Lo, Shih-Yen [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Graduate Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Liou, Je-Wen [Graduate Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Department of Biochemistry, Tzu Chi University, Hualien, Taiwan (China); Lin, Min-Ching [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Syu, Ciao-Ling [Graduate Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Lai, Meng-Jiun; Chen, Yi- Cheng [Graduate Institute of Medical Biotechnology, Tzu Chi University, Hualien, Taiwan (China); Li, Hui-Chun, E-mail: huichun@mail.tcu.edu.tw [Graduate Institute of Molecular and Cellular Biology, Tzu Chi University, Hualien, Taiwan (China); Graduate Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Department of Biochemistry, Tzu Chi University, Hualien, Taiwan (China)

    2011-01-07

    Research highlights: {yields} Lipid rafts are known to play an important role in virus entry and virus assembly of many viruses. {yields} However, HCV is the first example of the association of lipid raft with viral RNA replication. {yields} Our results in this manuscript demonstrate that purified HCV RCs with associated lipid raft membrane appeared as distinct particles of around 0.7 um under EM and AFM. {yields} Knockdown of proteins associated with lipid raft suppressed the HCV replication and reduced the number of these particles. {yields} To our knowledge, structures of HCV RCs were demonstrated at its first time in this manuscript. -- Abstract: Hepatitis C viral RNA synthesis has been demonstrated to occur on a lipid raft membrane structure. Lipid raft membrane fraction purified by membrane flotation analysis was observed using transmission electron microscopy and atomic force microscopy. Particles around 0.7 um in size were found in lipid raft membrane fraction purified from hepatitis C virus (HCV) replicon but not their parental HuH7 cells. HCV NS5A protein was associated with these specialized particles. After several cycles of freezing-thawing, these particles would fuse into larger sizes up to 10 um. Knockdown of seven proteins associated with lipid raft (VAPA, COPG, RAB18, COMT, CDC42, DPP4, and KDELR2) of HCV replicon cells reduced the observed number of these particles and suppressed the HCV replication. Results in this study indicated that HCV replication complexes with associated lipid raft membrane form distinct particle structures of around 0.7 um as observed from transmission electron microscopy and atomic force microscopy.

  10. On the possibilities of polychromatic synchrotron radiation microtomography for visualization of internal structures of Rhodnius prolixus

    Science.gov (United States)

    Sena, G.; Almeida, A. P.; Braz, D.; Nogueira, L. P.; Soares, J.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Barroso, R. C.

    2015-10-01

    The recent years advancements in microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and a widely available technology, potentially useful for studies of insect's internal morphology. Phase Contrast X-Ray Synchrotron Microtomography (SR-PhC-μCT) is a non-destructive technique that allows the microanatomical investigations of Rhodnius prolixus, one of the most important insect vectors of Trypanosoma cruzi, the etiologic agent of Chagas' disease. In Latin America, vector control is the most useful method to prevent Chagas' disease, and a detailed knowledge of R. prolixus' interior structures is crucial for a better understanding of their function and evolution. Traditionally, in both biological morphology and anatomy, the internal structures of whole organisms or parts of them are accessed by dissecting or histological serial sectioning; so studying the internal structures of R. prolixus' head using SR-PhC-μCT is of great importance in researches on vector control. In this work, volume-rendered SR-PhC-μCT images of the heads of selected R. prolixus were obtained using the new set-up available at the SYRMEP beamline of ELETTRA (Trieste, Italy). In this new set-up, the outcoming beam from the ring is restrained before the monochromator and in a devoted end-station, absorption and phase contrast radiography and tomography set-up are available. The images obtained with polychromatic X-ray beam in phase contrast regimen and 2 μm resolution, showed details and organs of R. prolixus never seen before with SR-PhC-μCT.

  11. The use of radar and visual observations to characterize the surface structure of the planet Mercury

    Science.gov (United States)

    Clark, P. E.; Kobrick, M.; Jurgens, R. F.

    1985-01-01

    An analysis is conducted of available topographic profiles and scattering parameters derived from earth-based S- and X-band radar observations of Mercury, in order to determine the nature and origin of regional surface variations and structures that are typical of the planet. Attention is given to the proposal that intercrater plains on Mercury formed from extensive volcanic flooding during bombardment, so that most craters were formed on a partially molten surface and were thus obliterated, together with previously formed tectonic features.

  12. Structural visualization of expert nursing: Hemodialysis patient education program "behavior modification program for hemodialysis patients".

    Science.gov (United States)

    Oka, Michiyo; Kamiya, Chizuru; Sagawa, Mieko; Yamana, Eiko; Tsuru, Satoko

    2006-01-01

    Behavior modification programs (BMP) have been suggested to be useful for the self-management of hemodialysis (HD) patients. To provide more systematic care, we structured the procedure of the thinking process and care in BMPs as an algorithm. BMP developers produced a temporary algorithm based on previous studies, discussed it with nurses with BMP experience, and added and revised necessary items. As a result, an algorithm of BMP with high reproducibility that allows maintenance of consistent quality for the self-management of HD patients could be developed.

  13. The use of radar and visual observations to characterize the surface structure of the planet Mercury

    Science.gov (United States)

    Clark, P. E.; Kobrick, M.; Jurgens, R. F.

    1985-01-01

    An analysis is conducted of available topographic profiles and scattering parameters derived from earth-based S- and X-band radar observations of Mercury, in order to determine the nature and origin of regional surface variations and structures that are typical of the planet. Attention is given to the proposal that intercrater plains on Mercury formed from extensive volcanic flooding during bombardment, so that most craters were formed on a partially molten surface and were thus obliterated, together with previously formed tectonic features.

  14. 3D visualization of deformation structures and potential fluid pathways at the Grimsel Test Site

    Science.gov (United States)

    Schneeberger, Raphael; Kober, Florian; Berger, Alfons; Spillmann, Thomas; Herwegh, Marco

    2015-04-01

    Knowledge on the ability of fluids to infiltrate subsurface rocks is of major importance for underground constructions, geothermal or radioactive waste disposal projects. In this study, we focus on the characterization of water infiltration pathways, their 3D geometries and origins. Based on surface and subsurface mapping in combination with drill core data, we developed by the use of MoveTM (Midland Valley Exploration Ltd.) a 3D structural model of the Grimsel Test Site (GTS). GTS is an underground laboratory operated by NAGRA, the Swiss organisation responsible for the management of nuclear waste. It is located within a suite of post-Variscan magmatic bodies comprising former granitic and granodioritic melts, which are dissected by mafic and aplitic dikes. During Alpine orogeny, the suite was tectonically overprinted within two stages of ductile deformation (Wehrens et al., in prep.) followed by brittle overprint of some of the shear zones during the retrograde exhumation history. It is this brittle deformation, which controls today's water infiltration network. However, the associated fractures, cataclasites and fault gouges are controlled themselves by aforementioned pre-existing mechanical discontinuities, whose origin ranges back as far as to the magmatic stage. For example, two sets of vertically oriented mafic dikes (E-W and NW-SE striking) and compositional heterogeneities induced by magmatic segregation processes in the plutonic host rocks served as nucleation sites for Alpine strain localization. Subsequently, NE-SW, E-W and NW-SE striking ductile shear zones were formed, in combination with high temperature fracturing while dissecting the host rocks in a complex 3D pattern (Wehrens et al, in prep.). Whether the ductile shear zones have been subjected to brittle reactivation and can serve as infiltration pathways or not, depends strongly on their orientations with respect to the principal stress field. Especially where deformation structures intersect

  15. Communicating long-span timber structures with 3D computer visualization

    OpenAIRE

    Janols, Henrik

    2005-01-01

    One of the reasons for the low amount of timber in construction is a general lack of knowledge about timber engineering and how timber can be used to its full advantage. In this thesis the focus is 3D computer visualisation (3D VIZ) of non-residential long-span timber structures, used for storage, industry and sports where 3D VIZ is defined as a process where a 3D-model is enhanced with environmental information e.g. texture maps and realistic light effects. An area of interest is the possibi...

  16. On a Strongly Damped Wave Equation for the Flame Front

    Institute of Scientific and Technical Information of China (English)

    Claude-Michel BRAUNER; Luca LORENZI; Gregory I.SIVASHINSKY; Chuanju XU

    2010-01-01

    In two-dimensional free-interface problems,the front dynamics can be modeled by single parabolic equations such as the Kuramoto-Sivashinsky equation (K-S).However,away from the stability threshold,the structure of the front equation may be more in-volved.In this paper,a generalized K-S equation,a nonlinear wave equation with a strong damping operator,is considered.As a consequence,the associated semigroup turns out to be analytic.Asymptotic convergence to K-S is shown,while numerical results illustrate the dynamics.

  17. Module structure of interphotoreceptor retinoid-binding protein (IRBP may provide bases for its complex role in the visual cycle – structure/function study of Xenopus IRBP

    Directory of Open Access Journals (Sweden)

    Ghosh Debashis

    2007-08-01

    Full Text Available Abstract Background Interphotoreceptor retinoid-binding protein's (IRBP remarkable module structure may be critical to its role in mediating the transport of all-trans and 11-cis retinol, and 11-cis retinal between rods, cones, RPE and Müller cells during the visual cycle. We isolated cDNAs for Xenopus IRBP, and expressed and purified its individual modules, module combinations, and the full-length polypeptide. Binding of all-trans retinol, 11-cis retinal and 9-(9-anthroyloxy stearic acid were characterized by fluorescence spectroscopy monitoring ligand-fluorescence enhancement, quenching of endogenous protein fluorescence, and energy transfer. Finally, the X-ray crystal structure of module-2 was used to predict the location of the ligand-binding sites, and compare their structures among modules using homology modeling. Results The full-length Xenopus IRBP cDNA codes for a polypeptide of 1,197 amino acid residues beginning with a signal peptide followed by four homologous modules each ~300 amino acid residues in length. Modules 1 and 3 are more closely related to each other than either is to modules 2 and 4. Modules 1 and 4 are most similar to the N- and C-terminal modules of the two module IRBP of teleosts. Our data are consistent with the model that vertebrate IRBPs arose through two genetic duplication events, but that the middle two modules were lost during the evolution of the ray finned fish. The sequence of the expressed full-length IRBP was confirmed by liquid chromatography-tandem mass spectrometry. The recombinant full-length Xenopus IRBP bound all-trans retinol and 11-cis retinaldehyde at 3 to 4 sites with Kd's of 0.2 to 0.3 μM, and was active in protecting all-trans retinol from degradation. Module 2 showed selectivity for all-trans retinol over 11-cis retinaldehyde. The binding data are correlated to the results of docking of all-trans-retinol to the crystal structure of Xenopus module 2 suggesting two ligand-binding sites

  18. Laser detection of ultrasonic waves with concave portions of the wave fronts.

    Science.gov (United States)

    Korkh, Yulia; Perov, Dmitry; Rinkevich, Anatoly

    2012-10-01

    Special features of ultrasonic pulse wave field detection with concave regions of the wave fronts are investigated with the use of ultrasonic laser interferometry technique. Experimental proofs of the wave front with concave regions are obtained and it is found that the nonmonotonic wave front profiles are well described by the fourth-order even polynomial. The model proposed is applied to the investigation of the spatiotemporal structure of elastic wave fields on solid surfaces. The results obtained can be used for estimating the local wave front curvature.

  19. Visual inspection of sea bottom structures by an autonomous underwater vehicle.

    Science.gov (United States)

    Foresti, G L

    2001-01-01

    This paper describes a vision-based system for inspections of underwater structures, e.g., pipelines, cables, etc., by an autonomous underwater vehicle (AUV). Usually underwater inspections are performed by remote operated vehicles (ROVs) driven by human operators placed in a support vessel. However, this task is often challenging, especially in conditions of poor visibility or in presence of strong currents. The system proposed allows the AUV to accomplish the task in autonomy. Moreover, the use of a three-dimensional (3-D) model of the environment and of an extended Kalman filter (EKF) allows the guidance and the control of the vehicle in real time. Experiments done on real underwater images have demonstrated the validity of the proposed method and its efficiency in the case of critical and complex situations.

  20. Using a cross section to train veterinary students to visualize anatomical structures in three dimensions

    Science.gov (United States)

    Provo, Judy; Lamar, Carlton; Newby, Timothy

    2002-01-01

    A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test-retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed.

  1. Sphere quadtrees - A new data structure to support the visualization of spherically distributed data

    Science.gov (United States)

    Fekete, Gyorgy; Treinish, Lloyd

    1990-01-01

    The concept of the sphere quadtree (SQT) is introduced to enable the structuring of spherically distributed data to be consistent with its geometry and facilitate mapping of the data onto a flat file system. The SQT is based on the recursive subdivision of the spherical triangles that result from the projection of the faces of an icosahedron onto a sphere. The SQT concept is insensitive to the distortions that occur far from the equator in spherically distributed data sets. Geographic data can be shown at several levels and at any resolution, allowing a system of referencing between data sets of different resolutions as well as data that are not geographically registered. SQTs are found to facilitate the search for particular spherically distributed data sets and improve the efficiency of surface rendering algorithms.

  2. Real-time visualization of bridge structural response through wireless MEMS sensors

    Science.gov (United States)

    Chung, Hung-Chi; Enomoto, Tomoyuki; Loh, Kenneth; Shinozuka, Masanobu

    2004-07-01

    This study investigates the reliability and accuracy of wireless micro-electromechanical-system (MEMS)-type sensors in application of bridge structural vibration monitoring. With wireless capabilities added onto the developed sensors, it becomes unnecessary for engineers to connect enormous lengths of cables in order to measure vibration on bridges for instance. We investigated two types of MEMS accelerometers: the ADXL 202E and the Silicon Design 2210. To prove the validity of measuring acceleration by using these devices with wireless communication, we succeeded on measuring a pedestrian bridge's vibration under excitation loads in the center of span. The result had been compared with the traditional cabled sensor, PCB 393C. The wireless sensors were showed to be effective and much affordable to carry out the monitoring missions in situ.

  3. Three-Dimensional Dynamical Instabilities in Galactic Ionization Fronts

    CERN Document Server

    Whalen, D J; Whalen, Daniel J.; Norman, Michael L.

    2007-01-01

    Ionization front instabilities have long been of interest for their suspected role in a variety of phenomena in the galaxy, from the formation of bright rims and 'elephant trunks' in nebulae to triggered star formation in molecular clouds. Numerical treatments of these instabilities have historically been limited in both dimensionality and input physics, leaving important questions about their true evolution unanswered. We present the first three-dimensional radiation hydrodynamical calculations of both R-type and D-type ionization front instabilities in galactic environments (i.e., solar metallicity gas). Consistent with linear stability analyses of planar D-type fronts, our models exhibit many short-wavelength perturbations growing at early times that later evolve into fewer large-wavelength structures. The simulations demonstrate that both self-consistent radiative transfer and three-dimensional flow introduce significant morphological differences to unstable modes when compared to earlier two-dimensional ...

  4. Nonlinear hydrodynamic corrections to supersonic F-KPP wave fronts

    Science.gov (United States)

    Antoine, C.; Dumazer, G.; Nowakowski, B.; Lemarchand, A.

    2012-03-01

    We study the hydrodynamic corrections to the dynamics and structure of an exothermic chemical wave front of Fisher-Kolmogorov-Petrovskii-Piskunov (F-KPP) type which travels in a one-dimensional gaseous medium. We show in particular that its long time dynamics, cut-off sensitivity and leading edge behavior are almost entirely controlled by the hydrodynamic front speed correction δUh which characterizes the pushed nature of the front. Reducing the problem to an effective comoving heterogeneous F-KPP equation, we determine two analytical expressions for δUh: an accurate one, derived from a variational method, and an approximate one, from which one can assess the δUh sensitivity to the shear viscosity and heat conductivity of the fluid of interest.

  5. Visual Impairment

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Visual Impairment KidsHealth > For Teens > Visual Impairment Print A A ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual problem ...

  6. Visual field

    Science.gov (United States)

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  7. A water tunnel flow visualization study of the vortex flow structures on the F/A-18 aircraft

    Science.gov (United States)

    Sandlin, Doral R.; Ramirez, Edgar J.

    1991-01-01

    The vortex flow structures occurring on the F/A-18 aircraft at high angles of attack were studied. A water tunnel was used to gather flow visualization data on the forebody vortex and the wing leading edge extension vortex. The longitudinal location of breakdown of the leading edge vortex was found to be consistently dependent on the angle of attack. Other parameters such as Reynolds number, model scale, and model fidelity had little influence on the overall behavior of the flow structures studied. The lateral location of the forebody vortex system was greatly influenced by changes in the angle of sideslip. Strong interactions can occur between the leading edge extension vortex and the forebody vortex. Close attention was paid to vortex induced flows on various airframe components of the F/A-18. Reynolds number and angle of attack greatly affected the swirling intensity, and therefore the strength of the studied vortices. Water tunnel results on the F/A-18 correlated well with those obtained in similar studies at both full and sub scale levels. The water tunnel can provide, under certain conditions, good simulations of realistic flows in full scale configurations.

  8. Front Propagation in Stochastic Neural Fields

    KAUST Repository

    Bressloff, Paul C.

    2012-01-01

    We analyze the effects of extrinsic multiplicative noise on front propagation in a scalar neural field with excitatory connections. Using a separation of time scales, we represent the fluctuating front in terms of a diffusive-like displacement (wandering) of the front from its uniformly translating position at long time scales, and fluctuations in the front profile around its instantaneous position at short time scales. One major result of our analysis is a comparison between freely propagating fronts and fronts locked to an externally moving stimulus. We show that the latter are much more robust to noise, since the stochastic wandering of the mean front profile is described by an Ornstein-Uhlenbeck process rather than a Wiener process, so that the variance in front position saturates in the long time limit rather than increasing linearly with time. Finally, we consider a stochastic neural field that supports a pulled front in the deterministic limit, and show that the wandering of such a front is now subdiffusive. © 2012 Society for Industrial and Applied Mathematics.

  9. Visualization of boiling flow structure in a natural circulation boiling loop

    Energy Technology Data Exchange (ETDEWEB)

    Karmakar, Arnab; Paruya, Swapan, E-mail: swapanparuya@gmail.com

    2015-04-15

    Highlights: • Vapor–liquid jet flows in natural circulation boiling loop. • Flow patterns and their transitions during geysering instability in the loop. • Evaluation of the efficiency of the needle probe in detecting the vapor–liquid and boiling flow structure. - Abstract: The present study reports vapor–liquid jet flows, flow patterns and their transitions during geysering instability in a natural circulation boiling loop under varied inlet subcooling ΔT{sub sub} (30–50 °C) and heater power Q (4–5 kW). Video imaging, voltage measurement using impedance needle probe, measurement of local pressure and loop flow rate have been carried out in this study. Power spectra of the voltage, the pressure and the flow rate reveal that at a high ΔT{sub sub} the jet flows have long period (21.36–86.95 s) and they are very irregular with a number of harmonics. The period decreases and becomes regular with a decrease of ΔT{sub sub}. The periods of the jet flows at ΔT{sub sub} = 30–50 °C and Q = 4 kW are in close agreement with those obtained from the video imaging. The probe was found to be more efficient than the pressure sensor in detecting the jet flows within an uncertainty of 9.5% and in detecting a variety of bubble classes. Both the imaging and the probe consistently identify the bubbly flow/vapor-mushrooms transition or the bubbly flow/slug flow transition on decreasing ΔT{sub sub} or on increasing Q.

  10. Structural Model of the Relationships among Cognitive Processes, Visual Motor Integration, and Academic Achievement in Students with Mild Intellectual Disability (MID)

    Science.gov (United States)

    Taha, Mohamed Mostafa

    2016-01-01

    This study aimed to test a proposed structural model of the relationships and existing paths among cognitive processes (attention and planning), visual motor integration, and academic achievement in reading, writing, and mathematics. The study sample consisted of 50 students with mild intellectual disability or MID. The average age of these…

  11. A new look at an old visual system: structure and development of the compound eyes and optic ganglia of the brine shrimp Artemia salina Linnaeus, 1758 (Branchiopoda, anostraca).

    Science.gov (United States)

    Wildt, Miriam; Harzsch, Steffen

    2002-08-01

    Compared to research carried out on decapod crustaceans, the development of the visual system in representatives of the entomostracan crustaceans is poorly understood. However, the structural evolution of the arthropod visual system is an important topic in the new debate on arthropod relationships, and entomostracan crustaceans play a key role in this discussion. Hence, data on structure and ontogeny of the entomostracan visual system are likely to contribute new aspects to our understanding of arthropod phylogeny. Therefore, we explored the proliferation of neuronal stem cells (in vivo incorporation of bromodeoxyuridine) and the developmental expression of synaptic proteins (immunohistochemistry against synapsins) in the developing optic neuropils of the brine shrimp Artemia salina Linnaeus, 1758 (Crustacea, Entomostraca, Branchiopoda, Anostraca) from hatching to adulthood. The morphology of the adult visual system was examined in serial sections of plastic embedded specimens. Our results indicate that the cellular material that gives rise to the visual system (compound eyes and two optic ganglia) is contributed by the mitotic activity of neuronal stem cells that are arranged in three band-shaped proliferation zones. Synapsin-like immunoreactivity in the lamina ganglionaris and the medulla externa initiated only after the anlagen of the compound eyes had already formed, suggesting that the emergence of the two optic neuropils lags behind the proliferative action of these stem cells. Neurogenesis in A. salina is compared to similar processes in malacostracan crustaceans and possible phylogenetic implications are discussed.

  12. Integration of spectral domain optical coherence tomography with microperimetry generates unique datasets for the simultaneous identification of visual function and retinal structure in ophthalmological applications

    Science.gov (United States)

    Koulen, Peter; Gallimore, Gary; Vincent, Ryan D.; Sabates, Nelson R.; Sabates, Felix N.

    2011-06-01

    Conventional perimeters are used routinely in various eye disease states to evaluate the central visual field and to quantitatively map sensitivity. However, standard automated perimetry proves difficult for retina and specifically macular disease due to the need for central and steady fixation. Advances in instrumentation have led to microperimetry, which incorporates eye tracking for placement of macular sensitivity values onto an image of the macular fundus thus enabling a precise functional and anatomical mapping of the central visual field. Functional sensitivity of the retina can be compared with the observed structural parameters that are acquired with high-resolution spectral domain optical coherence tomography and by integration of scanning laser ophthalmoscope-driven imaging. Findings of the present study generate a basis for age-matched comparison of sensitivity values in patients with macular pathology. Microperimetry registered with detailed structural data performed before and after intervention treatments provides valuable information about macular function, disease progression and treatment success. This approach also allows for the detection of disease or treatment related changes in retinal sensitivity when visual acuity is not affected and can drive the decision making process in choosing different treatment regimens and guiding visual rehabilitation. This has immediate relevance for applications in central retinal vein occlusion, central serous choroidopathy, age-related macular degeneration, familial macular dystrophy and several other forms of retina related visual disability.

  13. Front propagation and rejuvenation in flipping processes

    Energy Technology Data Exchange (ETDEWEB)

    Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, P I [BOSTON UNIV; Antal, T [HARVARD UNIV; Ben - Avrahm, D [HARVARD UNIV

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess {Delta}{sub k} increases logarithmically, {Delta}{sub k} {approx_equal}ln k, with the distance k from the front. Third, the front exhibits ageing -- young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

  14. Representação visual de estruturas biológicas em materiais de ensino Visual representation of biological structures in teaching material

    Directory of Open Access Journals (Sweden)

    Marina Azevedo Morato

    1998-10-01

    Full Text Available Este trabalho foi motivado pela necessidade de se definir parâmetros de apresentação e tratamento da informação científica em materiais de ensino. Através de consultas a bibliotecas e a especialistas em ciências da saúde e artes gráficas e visuais, fez-se uma pesquisa que resultou na descrição comparativa entre as primeiras manifestações da ilustração científica na anatomia e a trajetória da representação visual do conhecimento sobre a célula. O estudo traz ainda exemplos significativos de ilustrações utilizadas como elementos de análise.Parameters must be defined for presenting and handling scientific information presented in the form of teaching materials. Through library research and consultations with specialists in the health sciences and in graphic arts and design, this study undertook a comparative description of the first examples of scientific illustrations of anatomy and the evolution of visual representations of knowledge on the cell. The study includes significant examples of illustrations which served as elements of analysis.

  15. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean)

    Science.gov (United States)

    Alemany, Daniela; Acha, Eduardo M.; Iribarne, Oscar O.

    2014-03-01

    The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and in ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets and fishing effort are positively associated with frontal zones.

  16. Declarative Visualization Queries

    Science.gov (United States)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    In an ideal interaction with machines, scientists may prefer to write declarative queries saying "what" they want from a machine than to write code stating "how" the machine is going to address the user request. For example, in relational database, users have long relied on specifying queries using Structured Query Language (SQL), a declarative language to request data results from a database management system. In the context of visualizations, we see that users are still writing code based on complex visualization toolkit APIs. With the goal of improving the scientists' experience of using visualization technology, we have applied this query-answering pattern to a visualization setting, where scientists specify what visualizations they want generated using a declarative SQL-like notation. A knowledge enhanced management system ingests the query and knows the following: (1) know how to translate the query into visualization pipelines; and (2) how to execute the visualization pipelines to generate the requested visualization. We define visualization queries as declarative requests for visualizations specified in an SQL like language. Visualization queries specify what category of visualization to generate (e.g., volumes, contours, surfaces) as well as associated display attributes (e.g., color and opacity), without any regards for implementation, thus allowing scientists to remain partially unaware of a wide range of visualization toolkit (e.g., Generic Mapping Tools and Visualization Toolkit) specific implementation details. Implementation details are only a concern for our knowledge-based visualization management system, which uses both the information specified in the query and knowledge about visualization toolkit functions to construct visualization pipelines. Knowledge about the use of visualization toolkits includes what data formats the toolkit operates on, what formats they output, and what views they can generate. Visualization knowledge, which is not

  17. Muon front end for the neutrino factory

    Directory of Open Access Journals (Sweden)

    C. T. Rogers

    2013-04-01

    Full Text Available In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

  18. Muon front end for the neutrino factory

    CERN Document Server

    Rogers, C T; Prior, G; Gilardoni, S; Neuffer, D; Snopok, P; Alekou, A; Pasternak, J

    2013-01-01

    In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

  19. Burning invariant manifolds in reactive front propagation

    CERN Document Server

    Mahoney, John; Mitchell, Kevin; Solomon, Tom

    2011-01-01

    We present theory and experiments on the dynamics of reaction fronts in a two-dimensional flow composed of a chain of alternating vortices. Inspired by the organization of passive transport by invariant manifolds, we introduce burning invariant manifolds (BIMs), which act as one-sided barriers to front propagation. The BIMs emerge from the theory when the advection-reaction- diffusion system is recast as an ODE for reaction front elements. Experimentally, we demonstrate how these BIMs can be measured and compare their behavior with simulation. Finally, a topological BIM formalism yields a maximum front propagation speed.

  20. Front blind spot crashes in Hong Kong.

    Science.gov (United States)

    Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

    2016-09-01

    In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper.

  1. Hadronic Light-Front Wavefunctions and QCD Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2001-02-02

    A fundamental goal in QCD is to understand the non-perturbative structure of hadrons at the amplitude level--not just the single-particle flavor, momentum, and helicity distributions of the quark constituents, but also the multi-quark, gluonic, and hidden-color correlations intrinsic to hadronic and nuclear wavefunctions. A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. A new type of jet production reaction, ''self-resolving diffractive interactions'' can provide direct information on the light-front wavefunctions of hadrons in terms of their quark and gluon degrees of freedom as well as the composition of nuclei in terms of their nucleon and mesonic degrees of freedom.

  2. Impact of distance-based metric learning on classification and visualization model performance and structure-activity landscapes

    Science.gov (United States)

    Kireeva, Natalia V.; Ovchinnikova, Svetlana I.; Kuznetsov, Sergey L.; Kazennov, Andrey M.; Tsivadze, Aslan Yu.

    2014-02-01

    This study concerns large margin nearest neighbors classifier and its multi-metric extension as the efficient approaches for metric learning which aimed to learn an appropriate distance/similarity function for considered case studies. In recent years, many studies in data mining and pattern recognition have demonstrated that a learned metric can significantly improve the performance in classification, clustering and retrieval tasks. The paper describes application of the metric learning approach to in silico assessment of chemical liabilities. Chemical liabilities, such as adverse effects and toxicity, play a significant role in drug discovery process, in silico assessment of chemical liabilities is an important step aimed to reduce costs and animal testing by complementing or replacing in vitro and in vivo experiments. Here, to our knowledge for the first time, a distance-based metric learning procedures have been applied for in silico assessment of chemical liabilities, the impact of metric learning on structure-activity landscapes and predictive performance of developed models has been analyzed, the learned metric was used in support vector machines. The metric learning results have been illustrated using linear and non-linear data visualization techniques in order to indicate how the change of metrics affected nearest neighbors relations and descriptor space.

  3. Visualizing the structural evolution of LSM/xYSZ composite cathodes for SOFC by in-situ neutron diffraction.

    Science.gov (United States)

    Chen, Yan; Yang, Ling; Ren, Fei; An, Ke

    2014-06-05

    Thermal stability of composite cathodes for solid oxide fuel cells, the mixtures of (La0.8Sr0.2)0.95MnO(3-δ) (LSM) and (Y2O3)(x)(ZrO2)(1-x) (xYSZ, x = 3, 6, 8 and 10), is determined using in-situ neutron diffraction. Thanks to the most advanced high flux neutron source, our work highlights the visualization of the phase evolutions in heterogeneous material systems at high temperatures, along with the analysis of the diffusion activities of transition metal ions that reveal the reaction mechanism and kinetics. It is found that the tetragonal-to-cubic phase transition in YSZ at T > 900°C leads to a heterogeneous redistribution of Mn ions. The subsequent reaction of LSM and YSZ occurring at T > 1100°C is revealed as a three-stage kinetic process, yielding La2Zr2O7, SrZrO3 and MnO. The diffusion activities of Y, Mn and La ions in the heterogeneous systems at elevated temperatures are derived by the structural analysis, and the three-stage reaction of YSZ and LSM is found strongly correlated to ions' behaviors as functions of temperature.

  4. Generalized detection of a turbulent front generated by an oscillating grid

    Science.gov (United States)

    Holzner, Markus; Liberzon, Alexander; Guala, Michele; Tsinober, Arkady; Kinzelbach, Wolfgang

    2006-11-01

    This report presents experimental results on the propagation of a turbulent front induced by an oscillating grid starting from rest. The purpose of this preliminary investigation is to implement and validate detection methods of the turbulent/non-turbulent interface, which are based on flow measurements (velocity and vorticity) and scalar intensity, for oscillating grid turbulence. This is done using particle image velocimetry (PIV) and fluorescent dye visualization, separately. The results of both techniques describe the spreading of the turbulent front, confirming the known dependency of the front location, H, on time, t. It is demonstrated, that the level-based detection of a turbulent front can be applied to an unsteady flow, such as grid turbulence advancing into a fluid at rest.

  5. Collisionless expansion of pulsed radio frequency plasmas. I. Front formation

    Science.gov (United States)

    Schröder, T.; Grulke, O.; Klinger, T.; Boswell, R. W.; Charles, C.

    2016-01-01

    The dynamics during plasma expansion are studied with the use of a versatile particle-in-cell simulation with a variable neutral gas density profile. The simulation is tailored to a radio frequency plasma expansion experiment [Schröder et al., J. Phys. D: Appl. Phys. 47(5), 055207 (2014)]. The experiment has shown the existence of a propagating ion front. The ion front features a strong electric field and features a sharp plasma potential drop similar to a double layer. However, the presented results of a first principle simulation show that, in general, the ion front does not have to be entangled with an electric field. The propagating electric field reflects the downstream ions, which stream with velocities up to twice as high as that of the ion front propagation. The observed ion density peak forms due to the accumulation of the reflected ions. The simulation shows that the ion front formation strongly depends on the initial ion density profile and is subject to a wave-breaking phenomenon. Virtual diagnostics in the code allow for a direct comparison with experimental results. Using this technique, the plateau forming in the wake of the plasma front could be indirectly verified in the expansion experiment. Although the simulation considers profiles only in one spatial dimensional, its results are qualitatively in a very good agreement with the laboratory experiment. It can successfully reproduce findings obtained by independent numerical models and simulations. This indicates that the effects of magnetic field structures and tangential inhomogeneities are not essential for the general expansion dynamic. The presented simulation will be used for a detailed parameter study dealt with in Paper II [Schröder et al., Phys. Plasma 23, 013512 (2016)] of this series.

  6. An Architecture for Real-Time Interpretation and Visualization of Structural Sensor Data in a Laboratory Environment

    Science.gov (United States)

    Doggett, William; Vazquez, Sixto

    2000-01-01

    A visualization system is being developed out of the need to monitor, interpret, and make decisions based on the information from several thousand sensors during experimental testing to facilitate development and validation of structural health monitoring algorithms. As an added benefit the system will enable complete real-time sensor assessment of complex test specimens. Complex structural specimens are routinely tested that have hundreds or thousands of sensors. During a test, it is impossible for a single researcher to effectively monitor all the sensors and subsequently interesting phenomena occur that are not recognized until post-test analysis. The ability to detect and alert the researcher to these unexpected phenomena as the test progresses will significantly enhance the understanding and utilization of complex test articles. Utilization is increased by the ability to halt a test when the health monitoring algorithm response is not satisfactory or when an unexpected phenomenon occurs, enabling focused investigation potentially through the installation of additional sensors. Often if the test continues, structural changes make it impossible to reproduce the conditions that exhibited the phenomena. The prohibitive time and costs associated with fabrication, sensoring, and subsequent testing of additional test articles generally makes it impossible to further investigate the phenomena. A scalable architecture is described to address the complex computational demands of structural health monitoring algorithm development and laboratory experimental test monitoring. The researcher monitors the test using a photographic quality 3D graphical model with actual sensor locations identified. In addition, researchers can quickly activate plots displaying time or load versus selected sensor response along with the expected values and predefined limits. The architecture has several key features. First, distributed dissimilar computers may be seamlessly integrated into the

  7. Tool to estimate optical metrics from summary wave-front analysis data in the human eye

    NARCIS (Netherlands)

    Jansonius, Nomdo M.

    2013-01-01

    Purpose Studies in the field of cataract and refractive surgery often report only summary wave-front analysis data data that are too condensed to allow for a retrospective calculation of metrics relevant to visual perception. The aim of this study was to develop a tool that can be used to estimate t

  8. Using Self-Organizing Neural Network Map Combined with Ward’s Clustering Algorithm for Visualization of Students’ Cognitive Structural Models about Aliveness Concept

    Directory of Open Access Journals (Sweden)

    Nurettin Yorek

    2016-01-01

    Full Text Available We propose an approach to clustering and visualization of students’ cognitive structural models. We use the self-organizing map (SOM combined with Ward’s clustering to conduct cluster analysis. In the study carried out on 100 subjects, a conceptual understanding test consisting of open-ended questions was used as a data collection tool. The results of analyses indicated that students constructed the aliveness concept by associating it predominantly with human. Motion appeared as the most frequently associated term with the aliveness concept. The results suggest that the aliveness concept has been constructed using anthropocentric and animistic cognitive structures. In the next step, we used the data obtained from the conceptual understanding test for training the SOM. Consequently, we propose a visualization method about cognitive structure of the aliveness concept.

  9. Data structures and visualization

    Science.gov (United States)

    Genomic tools for genetic improvement have been rapidly adopted in many livestock species over the past few years. This presents new challenges for data collection and management, as well as opportunities for analysis and presentation. The U.S. national dairy database currently includes genotypes fo...

  10. Observations and Effects of Dipolarization Fronts Observed in Earth's Magnetotail

    Science.gov (United States)

    Goldstein, Melvyn L.

    2011-01-01

    . Such studies provide insights into the particle acceleration mechanisms associated with substorm dipolarization, and, in turn, the effects of those acceleration mechanisms on the structure and evolution of dipolarization fronts.

  11. Front propagation into unstable states : universal algebraic convergence towards uniformly translating pulled fronts

    NARCIS (Netherlands)

    U. Ebert (Ute); W. van Saarloos

    1999-01-01

    textabstractDepending on the nonlinear equation of motion and on the initial conditions, different regions of a front may dominate the propagation mechanism. The most familiar case is the so-called pushed front, whose speed is determined by the nonlinearities in the front region itself. Pushed dynam

  12. Laplacian Instability of Planar Streamer Ionization Fronts: An Example of Pulled Front Analysis

    NARCIS (Netherlands)

    Derks, G.; Ebert, U.; Meulenbroek, B.

    2008-01-01

    Streamer ionization fronts are pulled fronts that propagate into a linearly unstable state; the spatial decay of the initial condition of a planar front selects dynamically one specific long-time attractor out of a continuous family. A stability analysis for perturbations in the transverse direction

  13. Laplacian Instability of Planar Streamer Ionization Fronts: An Example of Pulled Front Analysis

    NARCIS (Netherlands)

    Derks, G.; Ebert, U.; Meulenbroek, B.

    2008-01-01

    Streamer ionization fronts are pulled fronts that propagate into a linearly unstable state; the spatial decay of the initial condition of a planar front selects dynamically one specific long-time attractor out of a continuous family. A stability analysis for perturbations in the transverse direction

  14. The Role of Front-Back Features in Children's 'Front', 'Back', and 'Beside' Placements of Objects.

    Science.gov (United States)

    Harris, Lauren; Strommen, Ellen

    1970-01-01

    In a study of spatial orientation, 40 boys and 40 girls from kindergarten and first grade placed a series of objects in front, behind, and beside themselves, and in front, behind, and beside other objects. Some objects had distinguishable front and back sides; others lacked such features. Placements were highly consistent within and across…

  15. Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

    DEFF Research Database (Denmark)

    Brodsky, S. J.; de Teramond, G. F.

    2012-01-01

    amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schrodinger equation which determines...

  16. Bringing the Fuzzy Front End into Focus

    Energy Technology Data Exchange (ETDEWEB)

    Beck, D.F.; Boyack, K.W.; Bray, O.H.; Siemens, W.D.

    1999-03-03

    Technology planning is relatively straightforward for well-established research and development (R and D) areas--those areas in which an organization has a history, the competitors are well understood, and the organization clearly knows where it is going with that technology. What we are calling the fuzzy front-end in this paper is that condition in which these factors are not well understood--such as for new corporate thrusts or emerging areas where the applications are embryonic. While strategic business planning exercises are generally good at identifying technology areas that are key to future success, they often lack substance in answering questions like: (1) Where are we now with respect to these key technologies? ... with respect to our competitors? (2) Where do we want or need to be? ... by when? (3) What is the best way to get there? In response to its own needs in answering such questions, Sandia National Laboratories is developing and implementing several planning tools. These tools include knowledge mapping (or visualization), PROSPERITY GAMES and technology roadmapping--all three of which are the subject of this paper. Knowledge mapping utilizes computer-based tools to help answer Question 1 by graphically representing the knowledge landscape that we populate as compared with other corporate and government entities. The knowledge landscape explored in this way can be based on any one of a number of information sets such as citation or patent databases. PROSPERITY GAMES are high-level interactive simulations, similar to seminar war games, which help address Question 2 by allowing us to explore consequences of various optional goals and strategies with all of the relevant stakeholders in a risk-free environment. Technology roadmapping is a strategic planning process that helps answer Question 3 by collaboratively identifying product and process performance targets and obstacles, and the technology alternatives available to reach those targets.

  17. Scientific visualization uncertainty, multifield, biomedical, and scalable visualization

    CERN Document Server

    Chen, Min; Johnson, Christopher; Kaufman, Arie; Hagen, Hans

    2014-01-01

    Based on the seminar that took place in Dagstuhl, Germany in June 2011, this contributed volume studies the four important topics within the scientific visualization field: uncertainty visualization, multifield visualization, biomedical visualization and scalable visualization. • Uncertainty visualization deals with uncertain data from simulations or sampled data, uncertainty due to the mathematical processes operating on the data, and uncertainty in the visual representation, • Multifield visualization addresses the need to depict multiple data at individual locations and the combination of multiple datasets, • Biomedical is a vast field with select subtopics addressed from scanning methodologies to structural applications to biological applications, • Scalability in scientific visualization is critical as data grows and computational devices range from hand-held mobile devices to exascale computational platforms. Scientific Visualization will be useful to practitioners of scientific visualization, ...

  18. Multiple front propagation into unstable states

    CERN Document Server

    Montagne, R; Hernández-García, E; Miguel, M S

    1993-01-01

    The dynamics of transient patterns formed by front propagation in extended nonequilibrium systems is considered. Under certain circumstances, the state left behind a front propagating into an unstable homogeneous state can be an unstable periodic pattern. It is found by a numerical solution of a model of the Fr\\'eedericksz transition in nematic liquid crystals that the mechanism of decay of such periodic unstable states is the propagation of a second front which replaces the unstable pattern by a another unstable periodic state with larger wavelength. The speed of this second front and the periodicity of the new state are analytically calculated with a generalization of the marginal stability formalism suited to the study of front propagation into periodic unstable states. PACS: 47.20.Ky, 03.40.Kf, 47.54.+r

  19. Wind and thermodynamic profiler observations of a late-mature gust front

    Indian Academy of Sciences (India)

    Haldun Karan

    2014-02-01

    High temporal and vertical resolutions of kinematic and thermodynamic characteristics of a late-mature gust front are presented using the Mobile Integrated Profiling System andWeather Surveillance Radar 88 Doppler data. As the gust front passed over the Mobile Integrated Profiling System vertical velocities and the horizontal wind field with 1 and 1.5 min temporal resolutions, respectively, were sampled within the gust front updrafts, gust frontal head and body structures. A 12-channel microwave profiling radiometer was used to delineate the thermodynamic properties with 5–6 min temporal and 100 m vertical resolution. Lidar backscatter from the 0.906 m ceilometer was also used to demonstrate the cloud field and the gust front depth. The gust front structurally and dynamically resembled laboratory simulated density current, and was composed of an elevated forward protrusion of a nose, and a turbulent mixing region at the top behind the head. The updrafts associated with the gust front that was moving into a stable layer were not surface rooted. Rather, the updrafts less than 3.5 ms−1 were observed 500 m above ground level during the gust front passage. These updrafts were present from above the nose level to top of the head. The observations indicated that kinematic and thermodynamic characteristics of the atmospheric boundary layer significantly influenced the propagation speed, updraft characteristics, and overall structural organization of the gust front. The observations validated that observed propagation speed of the gust front was in close agreement with the calculated propagation speed by integrating the buoyancy term within the gust front depth.

  20. Wick Rotation in the Light-Front

    CERN Document Server

    de Melo, J P B C J; Frederico, T

    2008-01-01

    We study the electroweak properties of pseudo-scalar mesons in the light and heavy-light sectors. In particular, we address the electromagnetic form factors and decay constants of the pion, kaon and D mesons. The structure of composite systems are given by the Bethe-Salpeter (BS) amplitude of a meson formed by a confined pair of constituent quark and antiquark, which in our work is written in terms of Pauli-Villars regulators. The analytical structure contains single poles in the complex momentum space. The BS amplitude takes into account poles due to the regulator parameters, while the quark-antiquark cut is avoided, implying in confined quarks with the property that the sum of the constituents masses can be larger than the mass of the meson. The one-loop expressions of the electroweak transition amplitudes are conveniently written in terms of light-front momentum. Technically, we introduce a Wick-rotation of he minus component of the momentum (k-minus) in the one-loop amplitudes allowing to avoid the cuts i...