The visual attention saliency map for movie retrospection

Science.gov (United States)

Rogalska, Anna; Napieralski, Piotr

2018-04-01

The visual saliency map is becoming important and challenging for many scientific disciplines (robotic systems, psychophysics, cognitive neuroscience and computer science). Map created by the model indicates possible salient regions by taking into consideration face presence and motion which is essential in motion pictures. By combining we can obtain credible saliency map with a low computational cost.

Visualization of disciplinary profiles: Enhanced science overlay maps

NARCIS (Netherlands)

Carley, S.; Porter, A.L.; Rafols, I.; Leydesdorff, L.

Purpose The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps.

The T?lz Temporal Topography Study: Mapping the visual field across the life span. Part II: Cognitive factors shaping visual field maps

OpenAIRE

Poggel, Dorothe A.; Treutwein, Bernhard; Calmanti, Claudia; Strasburger, Hans

2012-01-01

Part I described the topography of visual performance over the life span. Performance decline was explained only partly by deterioration of the optical apparatus. Part II therefore examines the influence of higher visual and cognitive functions. Visual field maps for 95 healthy observers of static perimetry, double-pulse resolution (DPR), reaction times, and contrast thresholds, were correlated with measures of visual attention (alertness, divided attention, spatial cueing), visual search, an...

The visual attention saliency map for movie retrospection

Directory of Open Access Journals (Sweden)

Rogalska Anna

2018-04-01

Full Text Available The visual saliency map is becoming important and challenging for many scientific disciplines (robotic systems, psychophysics, cognitive neuroscience and computer science. Map created by the model indicates possible salient regions by taking into consideration face presence and motion which is essential in motion pictures. By combining we can obtain credible saliency map with a low computational cost.

Synergy Maps: exploring compound combinations using network-based visualization.

Science.gov (United States)

Lewis, Richard; Guha, Rajarshi; Korcsmaros, Tamás; Bender, Andreas

2015-01-01

The phenomenon of super-additivity of biological response to compounds applied jointly, termed synergy, has the potential to provide many therapeutic benefits. Therefore, high throughput screening of compound combinations has recently received a great deal of attention. Large compound libraries and the feasibility of all-pairs screening can easily generate large, information-rich datasets. Previously, these datasets have been visualized using either a heat-map or a network approach-however these visualizations only partially represent the information encoded in the dataset. A new visualization technique for pairwise combination screening data, termed "Synergy Maps", is presented. In a Synergy Map, information about the synergistic interactions of compounds is integrated with information about their properties (chemical structure, physicochemical properties, bioactivity profiles) to produce a single visualization. As a result the relationships between compound and combination properties may be investigated simultaneously, and thus may afford insight into the synergy observed in the screen. An interactive web app implementation, available at http://richlewis42.github.io/synergy-maps, has been developed for public use, which may find use in navigating and filtering larger scale combination datasets. This tool is applied to a recent all-pairs dataset of anti-malarials, tested against Plasmodium falciparum, and a preliminary analysis is given as an example, illustrating the disproportionate synergism of histone deacetylase inhibitors previously described in literature, as well as suggesting new hypotheses for future investigation. Synergy Maps improve the state of the art in compound combination visualization, by simultaneously representing individual compound properties and their interactions. The web-based tool allows straightforward exploration of combination data, and easier identification of correlations between compound properties and interactions.

CellMap visualizes protein-protein interactions and subcellular localization

Science.gov (United States)

Dallago, Christian; Goldberg, Tatyana; Andrade-Navarro, Miguel Angel; Alanis-Lobato, Gregorio; Rost, Burkhard

2018-01-01

Many tools visualize protein-protein interaction (PPI) networks. The tool introduced here, CellMap, adds one crucial novelty by visualizing PPI networks in the context of subcellular localization, i.e. the location in the cell or cellular component in which a PPI happens. Users can upload images of cells and define areas of interest against which PPIs for selected proteins are displayed (by default on a cartoon of a cell). Annotations of localization are provided by the user or through our in-house database. The visualizer and server are written in JavaScript, making CellMap easy to customize and to extend by researchers and developers. PMID:29497493

StreamMap: Smooth Dynamic Visualization of High-Density Streaming Points.

Science.gov (United States)

Li, Chenhui; Baciu, George; Han, Yu

2018-03-01

Interactive visualization of streaming points for real-time scatterplots and linear blending of correlation patterns is increasingly becoming the dominant mode of visual analytics for both big data and streaming data from active sensors and broadcasting media. To better visualize and interact with inter-stream patterns, it is generally necessary to smooth out gaps or distortions in the streaming data. Previous approaches either animate the points directly or present a sampled static heat-map. We propose a new approach, called StreamMap, to smoothly blend high-density streaming points and create a visual flow that emphasizes the density pattern distributions. In essence, we present three new contributions for the visualization of high-density streaming points. The first contribution is a density-based method called super kernel density estimation that aggregates streaming points using an adaptive kernel to solve the overlapping problem. The second contribution is a robust density morphing algorithm that generates several smooth intermediate frames for a given pair of frames. The third contribution is a trend representation design that can help convey the flow directions of the streaming points. The experimental results on three datasets demonstrate the effectiveness of StreamMap when dynamic visualization and visual analysis of trend patterns on streaming points are required.

Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

DEFF Research Database (Denmark)

Rasmussen, Peter Mondrup; Hansen, Lars Kai; Madsen, Kristoffer Hougaard

There is significant current interest in decoding mental states from neuroimages. In this context kernel methods, e.g., support vector machines (SVM) are frequently adopted to learn statistical relations between patterns of brain activation and experimental conditions. In this paper we focus...... on visualization of such nonlinear kernel models. Specifically, we investigate the sensitivity map as a technique for generation of global summary maps of kernel classification methods. We illustrate the performance of the sensitivity map on functional magnetic resonance (fMRI) data based on visual stimuli. We...

Choosing colors for map display icons using models of visual search.

Science.gov (United States)

Shive, Joshua; Francis, Gregory

2013-04-01

We show how to choose colors for icons on maps to minimize search time using predictions of a model of visual search. The model analyzes digital images of a search target (an icon on a map) and a search display (the map containing the icon) and predicts search time as a function of target-distractor color distinctiveness and target eccentricity. We parameterized the model using data from a visual search task and performed a series of optimization tasks to test the model's ability to choose colors for icons to minimize search time across icons. Map display designs made by this procedure were tested experimentally. In a follow-up experiment, we examined the model's flexibility to assign colors in novel search situations. The model fits human performance, performs well on the optimization tasks, and can choose colors for icons on maps with novel stimuli to minimize search time without requiring additional model parameter fitting. Models of visual search can suggest color choices that produce search time reductions for display icons. Designers should consider constructing visual search models as a low-cost method of evaluating color assignments.

Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps

KAUST Repository

Bhatia, H.; Jadhav, S.; Bremer, P.; Guoning Chen,; Levine, J. A.; Nonato, L. G.; Pascucci, V.

2012-01-01

Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Traditional analysis and visualization techniques rely primarily on computing streamlines through numerical integration. The inherent numerical errors of such approaches are usually ignored, leading to inconsistencies that cause unreliable visualizations and can ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with maps from the triangle boundaries to themselves. This representation, called edge maps, permits a concise description of flow behaviors and is equivalent to computing all possible streamlines at a user defined error threshold. Independent of this error streamlines computed using edge maps are guaranteed to be consistent up to floating point precision, enabling the stable extraction of features such as the topological skeleton. Furthermore, our representation explicitly stores spatial and temporal errors which we use to produce more informative visualizations. This work describes the construction of edge maps, the error quantification, and a refinement procedure to adhere to a user defined error bound. Finally, we introduce new visualizations using the additional information provided by edge maps to indicate the uncertainty involved in computing streamlines and topological structures. © 2012 IEEE.

Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps

KAUST Repository

Bhatia, H.

2012-09-01

Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Traditional analysis and visualization techniques rely primarily on computing streamlines through numerical integration. The inherent numerical errors of such approaches are usually ignored, leading to inconsistencies that cause unreliable visualizations and can ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with maps from the triangle boundaries to themselves. This representation, called edge maps, permits a concise description of flow behaviors and is equivalent to computing all possible streamlines at a user defined error threshold. Independent of this error streamlines computed using edge maps are guaranteed to be consistent up to floating point precision, enabling the stable extraction of features such as the topological skeleton. Furthermore, our representation explicitly stores spatial and temporal errors which we use to produce more informative visualizations. This work describes the construction of edge maps, the error quantification, and a refinement procedure to adhere to a user defined error bound. Finally, we introduce new visualizations using the additional information provided by edge maps to indicate the uncertainty involved in computing streamlines and topological structures. © 2012 IEEE.

Spatio-temporal flow maps for visualizing movement and contact patterns

Directory of Open Access Journals (Sweden)

Bing Ni

2017-03-01

Full Text Available The advanced telecom technologies and massive volumes of intelligent mobile phone users have yielded a huge amount of real-time data of people’s all-in-one telecommunication records, which we call telco big data. With telco data and the domain knowledge of an urban city, we are now able to analyze the movement and contact patterns of humans in an unprecedented scale. Flow map is widely used to display the movements of humans from one single source to multiple destinations by representing locations as nodes and movements as edges. However, it fails the task of visualizing both movement and contact data. In addition, analysts often need to compare and examine the patterns side by side, and do various quantitative analysis. In this work, we propose a novel spatio-temporal flow map layout to visualize when and where people from different locations move into the same places and make contact. We also propose integrating the spatiotemporal flow maps into existing spatiotemporal visualization techniques to form a suite of techniques for visualizing the movement and contact patterns. We report a potential application the proposed techniques can be applied to. The results show that our design and techniques properly unveil hidden information, while analysis can be achieved efficiently. Keywords: Spatio-temporal data, Flow map, Urban mobility

Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps.

Science.gov (United States)

Sood, Mariam R; Sereno, Martin I

2016-08-01

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I. Hum Brain Mapp 37:2784-2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

SLAMM: Visual monocular SLAM with continuous mapping using multiple maps.

Directory of Open Access Journals (Sweden)

Hayyan Afeef Daoud

Full Text Available This paper presents the concept of Simultaneous Localization and Multi-Mapping (SLAMM. It is a system that ensures continuous mapping and information preservation despite failures in tracking due to corrupted frames or sensor's malfunction; making it suitable for real-world applications. It works with single or multiple robots. In a single robot scenario the algorithm generates a new map at the time of tracking failure, and later it merges maps at the event of loop closure. Similarly, maps generated from multiple robots are merged without prior knowledge of their relative poses; which makes this algorithm flexible. The system works in real time at frame-rate speed. The proposed approach was tested on the KITTI and TUM RGB-D public datasets and it showed superior results compared to the state-of-the-arts in calibrated visual monocular keyframe-based SLAM. The mean tracking time is around 22 milliseconds. The initialization is twice as fast as it is in ORB-SLAM, and the retrieved map can reach up to 90 percent more in terms of information preservation depending on tracking loss and loop closure events. For the benefit of the community, the source code along with a framework to be run with Bebop drone are made available at https://github.com/hdaoud/ORBSLAMM.

Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

Science.gov (United States)

Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

2003-01-01

To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

A new method for mapping perceptual biases across visual space.

Science.gov (United States)

Finlayson, Nonie J; Papageorgiou, Andriani; Schwarzkopf, D Samuel

2017-08-01

How we perceive the environment is not stable and seamless. Recent studies found that how a person qualitatively experiences even simple visual stimuli varies dramatically across different locations in the visual field. Here we use a method we developed recently that we call multiple alternatives perceptual search (MAPS) for efficiently mapping such perceptual biases across several locations. This procedure reliably quantifies the spatial pattern of perceptual biases and also of uncertainty and choice. We show that these measurements are strongly correlated with those from traditional psychophysical methods and that exogenous attention can skew biases without affecting overall task performance. Taken together, MAPS is an efficient method to measure how an individual's perceptual experience varies across space.

Visualization of neural networks using saliency maps

DEFF Research Database (Denmark)

Mørch, Niels J.S.; Kjems, Ulrik; Hansen, Lars Kai

1995-01-01

The saliency map is proposed as a new method for understanding and visualizing the nonlinearities embedded in feedforward neural networks, with emphasis on the ill-posed case, where the dimensionality of the input-field by far exceeds the number of examples. Several levels of approximations...

Advanced Visual Quantum Mechanics

CERN Document Server

Thaller, Bernd

2005-01-01

Advanced Visual Quantum Mechanics is a systematic effort to investigate and to teach quantum mechanics with the aid of computer-generated animations. It is a self-contained textbook that combines selected topics from atomic physics (spherical symmetry, the hydrogen atom, and particles with spin) with an introduction to quantum information theory (qubits, EPR paradox, teleportation, quantum computers). It explores relativistic quantum mechanics and the strange behavior of Dirac equation solutions. A series of appendices covers important topics from perturbation and scattering theory. The book places an emphasis on ideas and concepts, with a fair to moderate amount of mathematical rigor. Though this book stands alone, it can also be paired with Thaller Visual Quantum Mechanics to form a comprehensive course in quantum mechanics. The software for the first book earned the European Academic Software Award 2000 for outstanding innovation in its field.

Map Archive Mining: Visual-Analytical Approaches to Explore Large Historical Map Collections

Directory of Open Access Journals (Sweden)

Johannes H. Uhl

2018-04-01

Full Text Available Historical maps are unique sources of retrospective geographical information. Recently, several map archives containing map series covering large spatial and temporal extents have been systematically scanned and made available to the public. The geographical information contained in such data archives makes it possible to extend geospatial analysis retrospectively beyond the era of digital cartography. However, given the large data volumes of such archives (e.g., more than 200,000 map sheets in the United States Geological Survey topographic map archive and the low graphical quality of older, manually-produced map sheets, the process to extract geographical information from these map archives needs to be automated to the highest degree possible. To understand the potential challenges (e.g., salient map characteristics and data quality variations in automating large-scale information extraction tasks for map archives, it is useful to efficiently assess spatio-temporal coverage, approximate map content, and spatial accuracy of georeferenced map sheets at different map scales. Such preliminary analytical steps are often neglected or ignored in the map processing literature but represent critical phases that lay the foundation for any subsequent computational processes including recognition. Exemplified for the United States Geological Survey topographic map and the Sanborn fire insurance map archives, we demonstrate how such preliminary analyses can be systematically conducted using traditional analytical and cartographic techniques, as well as visual-analytical data mining tools originating from machine learning and data science.

Visualizing the semantic content of large text databases using text maps

Science.gov (United States)

Combs, Nathan

1993-01-01

A methodology for generating text map representations of the semantic content of text databases is presented. Text maps provide a graphical metaphor for conceptualizing and visualizing the contents and data interrelationships of large text databases. Described are a set of experiments conducted against the TIPSTER corpora of Wall Street Journal articles. These experiments provide an introduction to current work in the representation and visualization of documents by way of their semantic content.

Evolution of attention mechanisms for early visual processing

Science.gov (United States)

Müller, Thomas; Knoll, Alois

2011-03-01

Early visual processing as a method to speed up computations on visual input data has long been discussed in the computer vision community. The general target of a such approaches is to filter nonrelevant information from the costly higher-level visual processing algorithms. By insertion of this additional filter layer the overall approach can be speeded up without actually changing the visual processing methodology. Being inspired by the layered architecture of the human visual processing apparatus, several approaches for early visual processing have been recently proposed. Most promising in this field is the extraction of a saliency map to determine regions of current attention in the visual field. Such saliency can be computed in a bottom-up manner, i.e. the theory claims that static regions of attention emerge from a certain color footprint, and dynamic regions of attention emerge from connected blobs of textures moving in a uniform way in the visual field. Top-down saliency effects are either unconscious through inherent mechanisms like inhibition-of-return, i.e. within a period of time the attention level paid to a certain region automatically decreases if the properties of that region do not change, or volitional through cognitive feedback, e.g. if an object moves consistently in the visual field. These bottom-up and top-down saliency effects have been implemented and evaluated in a previous computer vision system for the project JAST. In this paper an extension applying evolutionary processes is proposed. The prior vision system utilized multiple threads to analyze the regions of attention delivered from the early processing mechanism. Here, in addition, multiple saliency units are used to produce these regions of attention. All of these saliency units have different parameter-sets. The idea is to let the population of saliency units create regions of attention, then evaluate the results with cognitive feedback and finally apply the genetic mechanism

Declarative and Scalable Selection for Map Visualizations

DEFF Research Database (Denmark)

Kefaloukos, Pimin Konstantin Balic

and is itself a source and cause of prolific data creation. This calls for scalable map processing techniques that can handle the data volume and which play well with the predominant data models on the Web. (4) Maps are now consumed around the clock by a global audience. While historical maps were singleuser......-defined constraints as well as custom objectives. The purpose of the language is to derive a target multi-scale database from a source database according to holistic specifications. (b) The Glossy SQL compiler allows Glossy SQL to be scalably executed in a spatial analytics system, such as a spatial relational......, there are indications that the method is scalable for databases that contain millions of records, especially if the target language of the compiler is substituted by a cluster-ready variant of SQL. While several realistic use cases for maps have been implemented in CVL, additional non-geographic data visualization uses...

Neural Mechanisms of Selective Visual Attention.

Science.gov (United States)

Moore, Tirin; Zirnsak, Marc

2017-01-03

Selective visual attention describes the tendency of visual processing to be confined largely to stimuli that are relevant to behavior. It is among the most fundamental of cognitive functions, particularly in humans and other primates for whom vision is the dominant sense. We review recent progress in identifying the neural mechanisms of selective visual attention. We discuss evidence from studies of different varieties of selective attention and examine how these varieties alter the processing of stimuli by neurons within the visual system, current knowledge of their causal basis, and methods for assessing attentional dysfunctions. In addition, we identify some key questions that remain in identifying the neural mechanisms that give rise to the selective processing of visual information.

ResistoMap-online visualization of human gut microbiota antibiotic resistome.

Science.gov (United States)

Yarygin, Konstantin S; Kovarsky, Boris A; Bibikova, Tatyana S; Melnikov, Damir S; Tyakht, Alexander V; Alexeev, Dmitry G

2017-07-15

We created ResistoMap—a Web-based interactive visualization of the presence of genetic determinants conferring resistance to antibiotics, biocides and heavy metals in human gut microbiota. ResistoMap displays the data on more than 1500 published gut metagenomes of world populations including both healthy subjects and patients. Multiparameter display filters allow visual assessment of the associations between the meta-data and proportions of resistome. The geographic map navigation layer allows to state hypotheses regarding the global trends of antibiotic resistance and correlates the gut resistome variations with the national clinical guidelines on antibiotics application. ResistoMap was implemented using AngularJS, CoffeeScript, D3.js and TopoJSON. The tool is publicly available at http://resistomap.rcpcm.org. yarygin@phystech.edu. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

The Tölz Temporal Topography Study: mapping the visual field across the life span. Part II: cognitive factors shaping visual field maps.

Science.gov (United States)

Poggel, Dorothe A; Treutwein, Bernhard; Calmanti, Claudia; Strasburger, Hans

2012-08-01

Part I described the topography of visual performance over the life span. Performance decline was explained only partly by deterioration of the optical apparatus. Part II therefore examines the influence of higher visual and cognitive functions. Visual field maps for 95 healthy observers of static perimetry, double-pulse resolution (DPR), reaction times, and contrast thresholds, were correlated with measures of visual attention (alertness, divided attention, spatial cueing), visual search, and the size of the attention focus. Correlations with the attentional variables were substantial, particularly for variables of temporal processing. DPR thresholds depended on the size of the attention focus. The extraction of cognitive variables from the correlations between topographical variables and participant age substantially reduced those correlations. There is a systematic top-down influence on the aging of visual functions, particularly of temporal variables, that largely explains performance decline and the change of the topography over the life span.

The Visual System

Medline Plus

Full Text Available ... with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the ... Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

Communicating and visualizing data quality through Web Map Services

Science.gov (United States)

Roberts, Charles; Blower, Jon; Maso, Joan; Diaz, Daniel; Griffiths, Guy; Lewis, Jane

2014-05-01

The sharing and visualization of environmental data through OGC Web Map Services is becoming increasingly common. However, information about the quality of data is rarely presented. (In this presentation we consider mostly data uncertainty as a measure of quality, although we acknowledge that many other quality measures are relevant to the geoscience community.) In the context of the GeoViQua project (http://www.geoviqua.org) we have developed conventions and tools for using WMS to deliver data quality information. The "WMS-Q" convention describes how the WMS specification can be used to publish quality information at the level of datasets, variables and individual pixels (samples). WMS-Q requires no extensions to the WMS 1.3.0 specification, being entirely backward-compatible. (An earlier version of WMS-Q was published as OGC Engineering Report 12-160.) To complement the WMS-Q convention, we have also developed extensions to the OGC Symbology Encoding (SE) specification, enabling uncertain geoscience data to be portrayed using a variety of visualization techniques. These include contours, stippling, blackening, whitening, opacity, bivariate colour maps, confidence interval triangles and glyphs. There may also be more extensive applications of these methods beyond the visual representation of uncertainty. In this presentation we will briefly describe the scope of the WMS-Q and "extended SE" specifications and then demonstrate the innovations using open-source software based upon ncWMS (http://ncwms.sf.net). We apply the tools to a variety of datasets including Earth Observation data from the European Space Agency's Climate Change Initiative. The software allows uncertain raster data to be shared through Web Map Services, giving the user fine control over data visualization.

Visual map and instruction-based bicycle navigation: a comparison of effects on behaviour.

Science.gov (United States)

de Waard, Dick; Westerhuis, Frank; Joling, Danielle; Weiland, Stella; Stadtbäumer, Ronja; Kaltofen, Leonie

2017-09-01

Cycling with a classic paper map was compared with navigating with a moving map displayed on a smartphone, and with auditory, and visual turn-by-turn route guidance. Spatial skills were found to be related to navigation performance, however only when navigating from a paper or electronic map, not with turn-by-turn (instruction based) navigation. While navigating, 25% of the time cyclists fixated at the devices that present visual information. Navigating from a paper map required most mental effort and both young and older cyclists preferred electronic over paper map navigation. In particular a turn-by-turn dedicated guidance device was favoured. Visual maps are in particular useful for cyclists with higher spatial skills. Turn-by-turn information is used by all cyclists, and it is useful to make these directions available in all devices. Practitioner Summary: Electronic navigation devices are preferred over a paper map. People with lower spatial skills benefit most from turn-by-turn guidance information, presented either auditory or on a dedicated device. People with higher spatial skills perform well with all devices. It is advised to keep in mind that all users benefit from turn-by-turn information when developing a navigation device for cyclists.

A Visual-Aided Inertial Navigation and Mapping System

Directory of Open Access Journals (Sweden)

Rodrigo Munguía

2016-05-01

Full Text Available State estimation is a fundamental necessity for any application involving autonomous robots. This paper describes a visual-aided inertial navigation and mapping system for application to autonomous robots. The system, which relies on Kalman filtering, is designed to fuse the measurements obtained from a monocular camera, an inertial measurement unit (IMU and a position sensor (GPS. The estimated state consists of the full state of the vehicle: the position, orientation, their first derivatives and the parameter errors of the inertial sensors (i.e., the bias of gyroscopes and accelerometers. The system also provides the spatial locations of the visual features observed by the camera. The proposed scheme was designed by considering the limited resources commonly available in small mobile robots, while it is intended to be applied to cluttered environments in order to perform fully vision-based navigation in periods where the position sensor is not available. Moreover, the estimated map of visual features would be suitable for multiple tasks: i terrain analysis; ii three-dimensional (3D scene reconstruction; iii localization, detection or perception of obstacles and generating trajectories to navigate around these obstacles; and iv autonomous exploration. In this work, simulations and experiments with real data are presented in order to validate and demonstrate the performance of the proposal.

Visualizing the Past: The Design of a Temporally Enabled Map for Presentation (TEMPO

Directory of Open Access Journals (Sweden)

Nathan Prestopnik

2012-01-01

Full Text Available We present a design case for a prototype visualization tool called the Temporally Enabled Map for Presentation (TEMPO. Designed for use in the lecture classroom, TEMPO is an interactive animated map that addressed a common problem in military history: the shortcomings of traditional static (non-interactive, non-animated maps. Static maps show spatial elements well, but cannot do more than approximate temporal events using multiple views, movement arrows, and the like. TEMPO provides a more complete view of past historical events by showing them from start to finish. In our design case we describe our development process, which included consultation with military history domain experts, classroom observations, application of techniques derived from visualization and Human-Computer Interaction (HCI literature and theory. Our design case shows how the design of an educational tool can motivate scholarly evaluation, and we describe how some theories were first embraced and then rejected as design circumstances required. Finally, we explore a future direction for TEMPO, tools to support creative interactions with visualizations where students or instructors can learn by visualizing historical events for themselves. A working version of the finished TEMPO artifact is included as an interactive element in this document.

Functional MRI mapping of visual function and selective attention for performance assessment and presurgical planning using conjunctive visual search.

Science.gov (United States)

Parker, Jason G; Zalusky, Eric J; Kirbas, Cemil

2014-03-01

Accurate mapping of visual function and selective attention using fMRI is important in the study of human performance as well as in presurgical treatment planning of lesions in or near visual centers of the brain. Conjunctive visual search (CVS) is a useful tool for mapping visual function during fMRI because of its greater activation extent compared with high-capacity parallel search processes. The purpose of this work was to develop and evaluate a CVS that was capable of generating consistent activation in the basic and higher level visual areas of the brain by using a high number of distractors as well as an optimized contrast condition. Images from 10 healthy volunteers were analyzed and brain regions of greatest activation and deactivation were determined using a nonbiased decomposition of the results at the hemisphere, lobe, and gyrus levels. The results were quantified in terms of activation and deactivation extent and mean z-statistic. The proposed CVS was found to generate robust activation of the occipital lobe, as well as regions in the middle frontal gyrus associated with coordinating eye movements and in regions of the insula associated with task-level control and focal attention. As expected, the task demonstrated deactivation patterns commonly implicated in the default-mode network. Further deactivation was noted in the posterior region of the cerebellum, most likely associated with the formation of optimal search strategy. We believe the task will be useful in studies of visual and selective attention in the neuroscience community as well as in mapping visual function in clinical fMRI.

Large Scale Topographic Maps Generalisation and Visualization Based on New Methodology

OpenAIRE

Dinar, Ilma; Ključanin, Slobodanka; Poslončec-Petrić, Vesna

2015-01-01

Integrating spatial data from different sources results in visualization which is the last step in the process of digital basic topographic maps creation. Sources used for visualization are existing real estate cadastre database orthophoto plans and digital terrain models. Analogue cadastre plans were scanned and georeferenced according to existing regulations and used for toponyms. Visualization of topologically inspected geometric primitives was performed based on the ''Collection of cartog...

System and method for image mapping and visual attention

Science.gov (United States)

Peters, II, Richard A. (Inventor)

2011-01-01

A method is described for mapping dense sensory data to a Sensory Ego Sphere (SES). Methods are also described for finding and ranking areas of interest in the images that form a complete visual scene on an SES. Further, attentional processing of image data is best done by performing attentional processing on individual full-size images from the image sequence, mapping each attentional location to the nearest node, and then summing all attentional locations at each node.

Synthesis maps: visual knowledge translation for the CanIMPACT clinical system and patient cancer journeys.

Science.gov (United States)

Jones, P H; Shakdher, S; Singh, P

2017-04-01

Salient findings and interpretations from the canimpact clinical cancer research study are visually represented in two synthesis maps for the purpose of communicating an integrated presentation of the study to clinical cancer researchers and policymakers. Synthesis maps integrate evidence and expertise into a visual narrative for knowledge translation and communication. A clinical system synthesis map represents the current Canadian primary care and cancer practice systems, proposed as a visual knowledge translation from the mixed-methods canimpact study to inform Canadian clinical research, policy, and practice discourses. Two synthesis maps, drawn together from multiple canimpact investigations and sources, were required to articulate critical differences between the clinical system and patient perspectives. The synthesis map of Canada-wide clinical cancer systems illustrates the relationships between primary care and the full cancer continuum. A patient-centred map was developed to represent the cancer (and primary care) journeys as experienced by breast and colorectal cancer patients.

Estimation of visual maps with a robot network equipped with vision sensors.

Science.gov (United States)

Gil, Arturo; Reinoso, Óscar; Ballesta, Mónica; Juliá, Miguel; Payá, Luis

2010-01-01

In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM) problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment.

Estimation of Visual Maps with a Robot Network Equipped with Vision Sensors

Directory of Open Access Journals (Sweden)

Arturo Gil

2010-05-01

Full Text Available In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment.

Synthesis maps: visual knowledge translation for the CanIMPACT clinical system and patient cancer journeys

OpenAIRE

Jones, P.H.; Shakdher, S.; Singh, P.

2017-01-01

Salient findings and interpretations from the canimpact clinical cancer research study are visually represented in two synthesis maps for the purpose of communicating an integrated presentation of the study to clinical cancer researchers and policymakers. Synthesis maps integrate evidence and expertise into a visual narrative for knowledge translation and communication. A clinical system synthesis map represents the current Canadian primary care and cancer practice systems, proposed as a visu...

Visualizing the topical structure of the medical sciences: a self-organizing map approach.

Directory of Open Access Journals (Sweden)

André Skupin

Full Text Available 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.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.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.

Visualizing the Quality of Vectur Features - a Proposal for Cadastral Maps

Science.gov (United States)

Navratil, G.; Leopoldseder, V.

2017-09-01

A well-known problem of geographical information is the communication of the quality level. It can be either done verbally / numerically or it can be done graphically. The graphical form is especially useful if the quality has a spatial variation because the spatial distribution is visualized as well. The problem of spatial variation of quality is an issue for cadastral maps. Non-experts cannot determine the quality at a specific location. Therefore a visual representation was tested for the Austrian cadastre. A map sheet was redesigned to give some indication of cadastral quality and presented to both experts and non-experts. The paper presents the result of the interviews.

Hierarchical tone mapping for high dynamic range image visualization

Science.gov (United States)

Qiu, Guoping; Duan, Jiang

2005-07-01

In this paper, we present a computationally efficient, practically easy to use tone mapping techniques for the visualization of high dynamic range (HDR) images in low dynamic range (LDR) reproduction devices. The new method, termed hierarchical nonlinear linear (HNL) tone-mapping operator maps the pixels in two hierarchical steps. The first step allocates appropriate numbers of LDR display levels to different HDR intensity intervals according to the pixel densities of the intervals. The second step linearly maps the HDR intensity intervals to theirs allocated LDR display levels. In the developed HNL scheme, the assignment of LDR display levels to HDR intensity intervals is controlled by a very simple and flexible formula with a single adjustable parameter. We also show that our new operators can be used for the effective enhancement of ordinary images.

MOST-visualization: software for producing automated textbook-style maps of genome-scale metabolic networks.

Science.gov (United States)

Kelley, James J; Maor, Shay; Kim, Min Kyung; Lane, Anatoliy; Lun, Desmond S

2017-08-15

Visualization of metabolites, reactions and pathways in genome-scale metabolic networks (GEMs) can assist in understanding cellular metabolism. Three attributes are desirable in software used for visualizing GEMs: (i) automation, since GEMs can be quite large; (ii) production of understandable maps that provide ease in identification of pathways, reactions and metabolites; and (iii) visualization of the entire network to show how pathways are interconnected. No software currently exists for visualizing GEMs that satisfies all three characteristics, but MOST-Visualization, an extension of the software package MOST (Metabolic Optimization and Simulation Tool), satisfies (i), and by using a pre-drawn overview map of metabolism based on the Roche map satisfies (ii) and comes close to satisfying (iii). MOST is distributed for free on the GNU General Public License. The software and full documentation are available at http://most.ccib.rutgers.edu/. dslun@rutgers.edu. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Mapping language to visual referents: Does the degree of image realism matter?

Science.gov (United States)

Saryazdi, Raheleh; Chambers, Craig G

2018-01-01

Studies of real-time spoken language comprehension have shown that listeners rapidly map unfolding speech to available referents in the immediate visual environment. This has been explored using various kinds of 2-dimensional (2D) stimuli, with convenience or availability typically motivating the choice of a particular image type. However, work in other areas has suggested that certain cognitive processes are sensitive to the level of realism in 2D representations. The present study examined the process of mapping language to depictions of objects that are more or less realistic, namely photographs versus clipart images. A custom stimulus set was first created by generating clipart images directly from photographs of real objects. Two visual world experiments were then conducted, varying whether referent identification was driven by noun or verb information. A modest benefit for clipart stimuli was observed during real-time processing, but only for noun-driving mappings. The results are discussed in terms of their implications for studies of visually situated language processing. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

AERYN: A simple standalone application for visualizing and enhancing elemental maps

International Nuclear Information System (INIS)

Mouchi, Vincent; Crowley, Quentin G.; Ubide, Teresa

2016-01-01

Interpretation of high spatial resolution elemental mineral maps can be hindered by high frequency fluctuations, as well as by strong naturally-occurring or analytically-induced variations. We have developed a new standalone program named AERYN (Aspect Enhancement by Removing Yielded Noise) to produce more reliable element distribution maps from previously reduced geochemical data. The program is Matlab-based, designed with a graphic user interface and is capable of rapidly generating elemental maps from data acquired by a range of analytical techniques. A visual interface aids selection of appropriate outlier rejection and drift-correction parameters, thereby facilitating recognition of subtle elemental fluctuations which may otherwise be obscured. Examples of use are provided for quantitative trace element maps acquired using both laser ablation (LA-) ICP-MS and electron probe microanalysis (EPMA) of the cold-water coral Lophelia pertusa. We demonstrate how AERYN allows recognition of high frequency elemental fluctuations, including those which occur perpendicular to the maximum concentration gradient. Such data treatment compliments commonly used processing methods to provide greater flexibility and control in producing elemental maps from micro-analytical techniques. - Highlights: • Matlab-based application to improve visualization of elemental maps. • Capable of detrending when data set shows drift. • Compatible with processed data text files from LA-ICP-MS, EDS and EPMA. • Option to filter geochemical trends to observe high-frequency fluctuations.

[Retinotopic mapping of the human visual cortex with functional magnetic resonance imaging - basic principles, current developments and ophthalmological perspectives].

Science.gov (United States)

Hoffmann, M B; Kaule, F; Grzeschik, R; Behrens-Baumann, W; Wolynski, B

2011-07-01

Since its initial introduction in the mid-1990 s, retinotopic mapping of the human visual cortex, based on functional magnetic resonance imaging (fMRI), has contributed greatly to our understanding of the human visual system. Multiple cortical visual field representations have been demonstrated and thus numerous visual areas identified. The organisation of specific areas has been detailed and the impact of pathophysiologies of the visual system on the cortical organisation uncovered. These results are based on investigations at a magnetic field strength of 3 Tesla or less. In a field-strength comparison between 3 and 7 Tesla, it was demonstrated that retinotopic mapping benefits from a magnetic field strength of 7 Tesla. Specifically, the visual areas can be mapped with high spatial resolution for a detailed analysis of the visual field maps. Applications of fMRI-based retinotopic mapping in ophthalmological research hold promise to further our understanding of plasticity in the human visual cortex. This is highlighted by pioneering studies in patients with macular dysfunction or misrouted optic nerves. © Georg Thieme Verlag KG Stuttgart · New York.

Adaptive Kalman filtering for real-time mapping of the visual field

Science.gov (United States)

Ward, B. Douglas; Janik, John; Mazaheri, Yousef; Ma, Yan; DeYoe, Edgar A.

2013-01-01

This paper demonstrates the feasibility of real-time mapping of the visual field for clinical applications. Specifically, three aspects of this problem were considered: (1) experimental design, (2) statistical analysis, and (3) display of results. Proper experimental design is essential to achieving a successful outcome, particularly for real-time applications. A random-block experimental design was shown to have less sensitivity to measurement noise, as well as greater robustness to error in modeling of the hemodynamic impulse response function (IRF) and greater flexibility than common alternatives. In addition, random encoding of the visual field allows for the detection of voxels that are responsive to multiple, not necessarily contiguous, regions of the visual field. Due to its recursive nature, the Kalman filter is ideally suited for real-time statistical analysis of visual field mapping data. An important feature of the Kalman filter is that it can be used for nonstationary time series analysis. The capability of the Kalman filter to adapt, in real time, to abrupt changes in the baseline arising from subject motion inside the scanner and other external system disturbances is important for the success of clinical applications. The clinician needs real-time information to evaluate the success or failure of the imaging run and to decide whether to extend, modify, or terminate the run. Accordingly, the analytical software provides real-time displays of (1) brain activation maps for each stimulus segment, (2) voxel-wise spatial tuning profiles, (3) time plots of the variability of response parameters, and (4) time plots of activated volume. PMID:22100663

JVM: Java Visual Mapping tool for next generation sequencing read.

Science.gov (United States)

Yang, Ye; Liu, Juan

2015-01-01

We developed a program JVM (Java Visual Mapping) for mapping next generation sequencing read to reference sequence. The program is implemented in Java and is designed to deal with millions of short read generated by sequence alignment using the Illumina sequencing technology. It employs seed index strategy and octal encoding operations for sequence alignments. JVM is useful for DNA-Seq, RNA-Seq when dealing with single-end resequencing. JVM is a desktop application, which supports reads capacity from 1 MB to 10 GB.

Visualizing Article Similarities via Sparsified Article Network and Map Projection for Systematic Reviews.

Science.gov (United States)

Ji, Xiaonan; Machiraju, Raghu; Ritter, Alan; Yen, Po-Yin

2017-01-01

Systematic Reviews (SRs) of biomedical literature summarize evidence from high-quality studies to inform clinical decisions, but are time and labor intensive due to the large number of article collections. Article similarities established from textual features have been shown to assist in the identification of relevant articles, thus facilitating the article screening process efficiently. In this study, we visualized article similarities to extend its utilization in practical settings for SR researchers, aiming to promote human comprehension of article distributions and hidden patterns. To prompt an effective visualization in an interpretable, intuitive, and scalable way, we implemented a graph-based network visualization with three network sparsification approaches and a distance-based map projection via dimensionality reduction. We evaluated and compared three network sparsification approaches and the visualization types (article network vs. article map). We demonstrated the effectiveness in revealing article distribution and exhibiting clustering patterns of relevant articles with practical meanings for SRs.

Mapping as a visual health communication tool: promises and dilemmas.

Science.gov (United States)

Parrott, Roxanne; Hopfer, Suellen; Ghetian, Christie; Lengerich, Eugene

2007-01-01

In the era of evidence-based public health promotion and planning, the use of maps as a form of evidence to communicate about the multiple determinants of cancer is on the rise. Geographic information systems and mapping technologies make future proliferation of this strategy likely. Yet disease maps as a communication form remain largely unexamined. This content analysis considers the presence of multivariate information, credibility cues, and the communication function of publicly accessible maps for cancer control activities. Thirty-six state comprehensive cancer control plans were publicly available in July 2005 and were reviewed for the presence of maps. Fourteen of the 36 state cancer plans (39%) contained map images (N = 59 static maps). A continuum of map inter activity was observed, with 10 states having interactive mapping tools available to query and map cancer information. Four states had both cancer plans with map images and interactive mapping tools available to the public on their Web sites. Of the 14 state cancer plans that depicted map images, two displayed multivariate data in a single map. Nine of the 10 states with interactive mapping capability offered the option to display multivariate health risk messages. The most frequent content category mapped was cancer incidence and mortality, with stage at diagnosis infrequently available. The most frequent communication function served by the maps reviewed was redundancy, as maps repeated information contained in textual forms. The social and ethical implications for communicating about cancer through the use of visual geographic representations are discussed.

Plasticity of orientation preference maps in the visual cortex of adult cats

Science.gov (United States)

Godde, Ben; Leonhardt, Ralph; Cords, Sven M.; Dinse, Hubert R.

2002-01-01

In contrast to the high degree of experience-dependent plasticity usually exhibited by cortical representational maps, a number of experiments performed in visual cortex suggest that the basic layout of orientation preference maps is only barely susceptible to activity-dependent modifications. In fact, most of what we know about activity-dependent plasticity in adults comes from experiments in somatosensory, auditory, or motor cortex. Applying a stimulation protocol that has been proven highly effective in other cortical areas, we demonstrate here that enforced synchronous cortical activity induces major changes of orientation preference maps (OPMs) in adult cats. Combining optical imaging of intrinsic signals and electrophysiological single-cell recordings, we show that a few hours of intracortical microstimulation (ICMS) lead to an enlargement of the cortical representational zone at the ICMS site and an extensive restructuring of the entire OPM layout up to several millimeters away, paralleled by dramatic changes of pinwheel numbers and locations. At the single-cell level, we found that the preferred orientation was shifted toward the orientation of the ICMS site over a region of up to 4 mm. Our results show that manipulating the synchronicity of cortical activity locally without invoking training, attention, or reinforcement, OPMs undergo large-scale reorganization reminiscent of plastic changes observed for nonvisual cortical maps. However, changes were much more widespread and enduring. Such large-scale restructuring of the visual cortical networks indicates a substantial capability for activity-dependent plasticity of adult visual cortex and may provide the basis for cognitive learning processes. PMID:11959906

A Multi-Objective Approach to Visualize Proportions and Similarities Between Individuals by Rectangular Maps

DEFF Research Database (Denmark)

Carrizosa, Emilio; Guerrero, Vanesa; Morales, Dolores Romero

In this paper we address the problem of visualizing the proportions and the similarities attached to a set of individuals. We represent this information using a rectangular map, i.e., a subdivision of a rectangle into rectangular portions so that each portion is associated with one individual...... area and adjacency requirements, this visualization problem is formulated as a three-objective Mixed Integer Nonlinear Problem. The first objective seeks to maximize the number of true adjacencies that the rectangular map is able to reproduce, the second one is to minimize the number of false...

Impact of visual impairment on the lives of young adults in the Netherlands: a concept-mapping approach.

Science.gov (United States)

Elsman, Ellen Bernadette Maria; van Rens, Gerardus Hermanus Maria Bartholomeus; van Nispen, Ruth Marie Antoinette

2017-12-01

While the impact of visual impairments on specific aspects of young adults' lives is well recognised, a systematic understanding of its impact on all life aspects is lacking. This study aims to provide an overview of life aspects affected by visual impairment in young adults (aged 18-25 years) using a concept-mapping approach. Visually impaired young adults (n = 22) and rehabilitation professionals (n = 16) participated in online concept-mapping workshops (brainstorm procedure), to explore how having a visual impairment influences the lives of young adults. Statements were categorised based on similarity and importance. Using multidimensional scaling, concept maps were produced and interpreted. A total of 59 and 260 statements were generated by young adults and professionals, respectively, resulting in 99 individual statements after checking and deduplication. The combined concept map revealed 11 clusters: work, study, information and regulations, social skills, living independently, computer, social relationships, sport and activities, mobility, leisure time, and hobby. The concept maps provided useful insight into activities influenced by visual impairments in young adults, which can be used by rehabilitation centres to improve their services. This might help in goal setting, rehabilitation referral and successful transition to adult life, ultimately increasing participation and quality of life. Implications for rehabilitation Having a visual impairment affects various life-aspects related to participation, including activities related to work, study, social skills and relationships, activities of daily living, leisure time and mobility. Concept-mapping helped to identify the life aspects affected by low vision, and quantify these aspects in terms of importance according to young adults and low vision rehabilitation professionals. Low vision rehabilitation centres should focus on all life aspects found in this study when identifying the needs of young

An Information-Theoretic-Cluster Visualization for Self-Organizing Maps.

Science.gov (United States)

Brito da Silva, Leonardo Enzo; Wunsch, Donald C

2018-06-01

Improved data visualization will be a significant tool to enhance cluster analysis. In this paper, an information-theoretic-based method for cluster visualization using self-organizing maps (SOMs) is presented. The information-theoretic visualization (IT-vis) has the same structure as the unified distance matrix, but instead of depicting Euclidean distances between adjacent neurons, it displays the similarity between the distributions associated with adjacent neurons. Each SOM neuron has an associated subset of the data set whose cardinality controls the granularity of the IT-vis and with which the first- and second-order statistics are computed and used to estimate their probability density functions. These are used to calculate the similarity measure, based on Renyi's quadratic cross entropy and cross information potential (CIP). The introduced visualizations combine the low computational cost and kernel estimation properties of the representative CIP and the data structure representation of a single-linkage-based grouping algorithm to generate an enhanced SOM-based visualization. The visual quality of the IT-vis is assessed by comparing it with other visualization methods for several real-world and synthetic benchmark data sets. Thus, this paper also contains a significant literature survey. The experiments demonstrate the IT-vis cluster revealing capabilities, in which cluster boundaries are sharply captured. Additionally, the information-theoretic visualizations are used to perform clustering of the SOM. Compared with other methods, IT-vis of large SOMs yielded the best results in this paper, for which the quality of the final partitions was evaluated using external validity indices.

Effect of tone mapping operators on visual attention deployment

Science.gov (United States)

Narwaria, Manish; Perreira Da Silva, Matthieu; Le Callet, Patrick; Pepion, Romuald

2012-10-01

High Dynamic Range (HDR) images/videos require the use of a tone mapping operator (TMO) when visualized on Low Dynamic Range (LDR) displays. From an artistic intention point of view, TMOs are not necessarily transparent and might induce different behavior to view the content. In this paper, we investigate and quantify how TMOs modify visual attention (VA). To that end both objective and subjective tests in the form of eye-tracking experiments have been conducted on several still image content that have been processed by 11 different TMOs. Our studies confirm that TMOs can indeed modify human attention and fixation behavior significantly. Therefore our studies suggest that VA needs consideration for evaluating the overall perceptual impact of TMOs on HDR content. Since the existing studies so far have only considered the quality or aesthetic appeal angle, this study brings in a new perspective regarding the importance of VA in HDR content processing for visualization on LDR displays.

Discussion on the 3D visualizing of 1:200 000 geological map

Science.gov (United States)

Wang, Xiaopeng

2018-01-01

Using United States National Aeronautics and Space Administration Shuttle Radar Topography Mission (SRTM) terrain data as digital elevation model (DEM), overlap scanned 1:200 000 scale geological map, program using Direct 3D of Microsoft with C# computer language, the author realized the three-dimensional visualization of the standard division geological map. User can inspect the regional geology content with arbitrary angle, rotating, roaming, and can examining the strata synthetical histogram, map section and legend at any moment. This will provide an intuitionistic analyzing tool for the geological practitioner to do structural analysis with the assistant of landform, dispose field exploration route etc.

Quantum mechanical wavefunction: visualization at undergraduate level

International Nuclear Information System (INIS)

Chhabra, Mahima; Das, Ritwick

2017-01-01

Quantum mechanics (QM) forms the most crucial ingredient of modern-era physical science curricula at undergraduate level. The abstract ideas involved in QM related concepts pose a challenge towards appropriate visualization as a consequence of their counter-intuitive nature and lack of experiment-assisted visualization tools. At the heart of the quantum mechanical formulation lies the concept of ‘wavefunction’, which forms the basis for understanding the behavior of physical systems. At undergraduate level, the concept of ‘wavefunction’ is introduced in an abstract framework using mathematical tools and therefore opens up an enormous scope for alternative conceptions and erroneous visualization. The present work is an attempt towards exploring the visualization models constructed by undergraduate students for appreciating the concept of ‘wavefunction’. We present a qualitative analysis of the data obtained from administering a questionnaire containing four visualization based questions on the topic of ‘wavefunction’ to a group of ten undergraduate-level students at an institute in India which excels in teaching and research of basic sciences. Based on the written responses, all ten students were interviewed in detail to unravel the exact areas of difficulty in visualization of ‘wavefunction’. The outcome of present study not only reveals the gray areas in students’ conceptualization, but also provides a plausible route to address the issues at the pedagogical level within the classroom. (paper)

Quantum mechanical wavefunction: visualization at undergraduate level

Science.gov (United States)

Chhabra, Mahima; Das, Ritwick

2017-01-01

Quantum mechanics (QM) forms the most crucial ingredient of modern-era physical science curricula at undergraduate level. The abstract ideas involved in QM related concepts pose a challenge towards appropriate visualization as a consequence of their counter-intuitive nature and lack of experiment-assisted visualization tools. At the heart of the quantum mechanical formulation lies the concept of ‘wavefunction’, which forms the basis for understanding the behavior of physical systems. At undergraduate level, the concept of ‘wavefunction’ is introduced in an abstract framework using mathematical tools and therefore opens up an enormous scope for alternative conceptions and erroneous visualization. The present work is an attempt towards exploring the visualization models constructed by undergraduate students for appreciating the concept of ‘wavefunction’. We present a qualitative analysis of the data obtained from administering a questionnaire containing four visualization based questions on the topic of ‘wavefunction’ to a group of ten undergraduate-level students at an institute in India which excels in teaching and research of basic sciences. Based on the written responses, all ten students were interviewed in detail to unravel the exact areas of difficulty in visualization of ‘wavefunction’. The outcome of present study not only reveals the gray areas in students’ conceptualization, but also provides a plausible route to address the issues at the pedagogical level within the classroom.

Topological mass mechanism and exact fields mapping

International Nuclear Information System (INIS)

Amaral, R L P G; Ventura, O S; Buffon, L O; Costa, J V

2006-01-01

We present a class of mappings between models with topological mass mechanism and purely topological models in arbitrary dimensions. These mappings are established by directly mapping the fields of one model in terms of the fields of the other model in closed expressions. These expressions provide the mappings of their actions as well as the mappings of their propagators. For a general class of models in which the topological model becomes the BF model the mappings present arbitrary functions which otherwise are absent for Chern-Simons like actions. This work generalizes the results of (Ventura O S, Amaral R L P G, Costa J V, Buffon L O and Lemes V E R 2004 J. Phys. A: Math. Gen. 37 11711-23) for arbitrary dimensions

Choropleth map legend design for visualizing community health disparities

Directory of Open Access Journals (Sweden)

Cromley Ellen K

2009-09-01

Full Text Available Abstract Background Disparities in health outcomes across communities are a central concern in public health and epidemiology. Health disparities research often links differences in health outcomes to other social factors like income. Choropleth maps of health outcome rates show the geographical distribution of health outcomes. This paper illustrates the use of cumulative frequency map legends for visualizing how the health events are distributed in relation to social characteristics of community populations. The approach uses two graphs in the cumulative frequency legend to highlight the difference between the raw count of the health events and the raw count of the social characteristic like low income in the geographical areas of the map. The approach is applied to mapping publicly available data on low birth weight by town in Connecticut and Lyme disease incidence by town in Connecticut in relation to income. The steps involved in creating these legends are described in detail so that health analysts can adopt this approach. Results The different health problems, low birth weight and Lyme disease, have different cumulative frequency signatures. Graphing poverty population on the cumulative frequency legends revealed that the poverty population is distributed differently with respect to the two different health problems mapped here. Conclusion Cumulative frequency legends can be useful supplements for choropleth maps. These legends can be constructed using readily available software. They contain all of the information found in standard choropleth map legends, and they can be used with any choropleth map classification scheme. Cumulative frequency legends effectively communicate the proportion of areas, the proportion of health events, and/or the proportion of the denominator population in which the health events occurred that falls within each class interval. They illuminate the context of disease through graphing associations with other

Automatic transfer function design for medical visualization using visibility distributions and projective color mapping.

Science.gov (United States)

Cai, Lile; Tay, Wei-Liang; Nguyen, Binh P; Chui, Chee-Kong; Ong, Sim-Heng

2013-01-01

Transfer functions play a key role in volume rendering of medical data, but transfer function manipulation is unintuitive and can be time-consuming; achieving an optimal visualization of patient anatomy or pathology is difficult. To overcome this problem, we present a system for automatic transfer function design based on visibility distribution and projective color mapping. Instead of assigning opacity directly based on voxel intensity and gradient magnitude, the opacity transfer function is automatically derived by matching the observed visibility distribution to a target visibility distribution. An automatic color assignment scheme based on projective mapping is proposed to assign colors that allow for the visual discrimination of different structures, while also reflecting the degree of similarity between them. When our method was tested on several medical volumetric datasets, the key structures within the volume were clearly visualized with minimal user intervention. Copyright © 2013 Elsevier Ltd. All rights reserved.

Entrainment and high-density three-dimensional mapping in right atrial macroreentry provide critical complementary information: Entrainment may unmask "visual reentry" as passive.

Science.gov (United States)

Pathik, Bhupesh; Lee, Geoffrey; Nalliah, Chrishan; Joseph, Stephen; Morton, Joseph B; Sparks, Paul B; Sanders, Prashanthan; Kistler, Peter M; Kalman, Jonathan M

2017-10-01

With the recent advent of high-density (HD) 3-dimensional (3D) mapping, the utility of entrainment is uncertain. However, the limitations of visual representation and interpretation of these high-resolution 3D maps are unclear. The purpose of this study was to determine the strengths and limitations of both HD 3D mapping and entrainment mapping during mapping of right atrial macroreentry. Fifteen patients were studied. The number and type of circuits accounting for ≥90% of the tachycardia cycle length using HD 3D mapping were verified using systematic entrainment mapping. Entrainment sites with an unexpectedly long postpacing interval despite proximity to the active circuit were evaluated. Based on HD 3D mapping, 27 circuits were observed: 12 peritricuspid, 2 upper loop reentry, 10 lower loop reentry, and 3 lateral wall circuits. With entrainment, 17 of the 27 circuits were active: all 12 peritricuspid and 2 upper loop reentry. However, lower loop reentry was confirmed in only 3 of 10, and none of the 3 lateral wall circuits were present. Mean percentage of tachycardia cycle length covered by active circuits was 98% ± 1% vs 97% ± 2% for passive circuits (P = .09). None of the 345 entrainment runs terminated tachycardia or changed tachycardia mechanism. In 8 of 15 patients, 13 examples of unexpectedly long postpacing interval were observed at entrainment sites located distal to localized zones of slow conduction seen on HD 3D mapping. Using HD 3D mapping, "visual reentry" may be due to passive circuitous propagation rather than a critical reentrant circuit. HD 3D mapping provides new insights into regional conduction and helps explain unusual entrainment phenomena. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

Directory of Open Access Journals (Sweden)

Francisco Amorós

2014-01-01

Full Text Available In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map. After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions.

Visualizing flow fields using acoustic Doppler current profilers and the Velocity Mapping Toolbox

Science.gov (United States)

Jackson, P. Ryan

2013-01-01

The purpose of this fact sheet is to provide examples of how the U.S. Geological Survey is using acoustic Doppler current profilers for much more than routine discharge measurements. These instruments are capable of mapping complex three-dimensional flow fields within rivers, lakes, and estuaries. Using the Velocity Mapping Toolbox to process the ADCP data allows detailed visualization of the data, providing valuable information for a range of studies and applications.

Preclinical medical students’ understandings of academic and medical professionalism: visual analysis of mind maps

Science.gov (United States)

Rees, Charlotte E

2017-01-01

Introduction Several studies have begun to explore medical students’ understandings of professionalism generally and medical professionalism specifically. Despite espoused relationships between academic (AP) and medical professionalism (MP), previous research has not yet investigated students’ conceptualisations of AP and MP and the relationships between the two. Objectives The current study, based on innovative visual analysis of mind maps, therefore aims to contribute to the developing literature on how professionalism is understood. Methods We performed a multilayered analysis of 98 mind maps from 262 first-year medical students, including analysing textual and graphical elements of AP, MP and the relationships between AP and MP. Results The most common textual attributes of AP were learning, lifestyle and personality, while attributes of MP were knowledge, ethics and patient-doctor relations. Images of books, academic caps and teachers were used most often to represent AP, while images of the stethoscope, doctor and red cross were used to symbolise MP. While AP-MP relations were sometimes indicated through co-occurring text, visual connections and higher-order visual metaphors, many students struggled to articulate the relationships between AP and MP. Conclusions While the mind maps’ textual attributes shared similarities with those found in previous research, suggesting the universality of some professionalism attributes, our study provides new insights into students’ conceptualisations of AP, MP and AP-MP relationships. We encourage medical educators to help students develop their understandings of AP, MP and AP-MP relationships, plus consider the feasibility and value of mind maps as a source of visual data for medical education research. PMID:28821520

Visual cortex in aging and Alzheimer’s disease: Changes in visual field maps and population receptive fields

Directory of Open Access Journals (Sweden)

Alyssa A. Brewer

2014-02-01

Full Text Available Although several studies have suggested that cortical alterations underlie such age-related visual deficits as decreased acuity, little is known about what changes actually occur in visual cortex during healthy aging. Two recent studies showed changes in primary visual cortex (V1 during normal aging; however, no studies have characterized the effects of aging on visual cortex beyond V1, important measurements both for understanding the aging process and for comparison to changes in age-related diseases. Similarly, there is almost no information about changes in visual cortex in Alzheimer’s disease (AD, the most common form of dementia. Because visual deficits are often reported as one of the first symptoms of AD, measurements of such changes in the visual cortex of AD patients might improve our understanding of how the visual system is affected by neurodegeneration as well as aid early detection, accurate diagnosis and timely treatment of AD. Here we use fMRI to first compare the visual field map (VFM organization and population receptive fields (pRFs between young adults and healthy aging subjects for occipital VFMs V1, V2, V3, and hV4. Healthy aging subjects do not show major VFM organizational deficits, but do have reduced surface area and increased pRF sizes in the foveal representations of V1, V2, and hV4 relative to healthy young control subjects. These measurements are consistent with behavioral deficits seen in healthy aging. We then demonstrate the feasibility and first characterization of these measurements in two patients with mild AD, which reveal potential changes in visual cortex as part of the pathophysiology of AD. Our data aid in our understanding of the changes in the visual processing pathways in normal aging and provide the foundation for future research into earlier and more definitive detection of AD.

Spatial frequency-dependent feedback of visual cortical area 21a modulating functional orientation column maps in areas 17 and 18 of the cat.

Science.gov (United States)

Huang, Luoxiu; Chen, Xin; Shou, Tiande

2004-02-20

The feedback effect of activity of area 21a on orientation maps of areas 17 and 18 was investigated in cats using intrinsic signal optical imaging. A spatial frequency-dependent decrease in response amplitude of orientation maps to grating stimuli was observed in areas 17 and 18 when area 21a was inactivated by local injection of GABA, or by a lesion induced by liquid nitrogen freezing. The decrease in response amplitude of orientation maps of areas 17 and 18 after the area 21a inactivation paralleled the normal response without the inactivation. Application in area 21a of bicuculline, a GABAa receptor antagonist caused an increase in response amplitude of orientation maps of area 17. The results indicate a positive feedback from high-order visual cortical area 21a to lower-order areas underlying a spatial frequency-dependent mechanism.

Facial motion engages predictive visual mechanisms.

Directory of Open Access Journals (Sweden)

Jordy Kaufman

Full Text Available We employed a novel cuing paradigm to assess whether dynamically versus statically presented facial expressions differentially engaged predictive visual mechanisms. Participants were presented with a cueing stimulus that was either the static depiction of a low intensity expressed emotion; or a dynamic sequence evolving from a neutral expression to the low intensity expressed emotion. Following this cue and a backwards mask, participants were presented with a probe face that displayed either the same emotion (congruent or a different emotion (incongruent with respect to that displayed by the cue although expressed at a high intensity. The probe face had either the same or different identity from the cued face. The participants' task was to indicate whether or not the probe face showed the same emotion as the cue. Dynamic cues and same identity cues both led to a greater tendency towards congruent responding, although these factors did not interact. Facial motion also led to faster responding when the probe face was emotionally congruent to the cue. We interpret these results as indicating that dynamic facial displays preferentially invoke predictive visual mechanisms, and suggest that motoric simulation may provide an important basis for the generation of predictions in the visual system.

Different Stimuli, Different Spatial Codes: A Visual Map and an Auditory Rate Code for Oculomotor Space in the Primate Superior Colliculus

Science.gov (United States)

Lee, Jungah; Groh, Jennifer M.

2014-01-01

Maps are a mainstay of visual, somatosensory, and motor coding in many species. However, auditory maps of space have not been reported in the primate brain. Instead, recent studies have suggested that sound location may be encoded via broadly responsive neurons whose firing rates vary roughly proportionately with sound azimuth. Within frontal space, maps and such rate codes involve different response patterns at the level of individual neurons. Maps consist of neurons exhibiting circumscribed receptive fields, whereas rate codes involve open-ended response patterns that peak in the periphery. This coding format discrepancy therefore poses a potential problem for brain regions responsible for representing both visual and auditory information. Here, we investigated the coding of auditory space in the primate superior colliculus(SC), a structure known to contain visual and oculomotor maps for guiding saccades. We report that, for visual stimuli, neurons showed circumscribed receptive fields consistent with a map, but for auditory stimuli, they had open-ended response patterns consistent with a rate or level-of-activity code for location. The discrepant response patterns were not segregated into different neural populations but occurred in the same neurons. We show that a read-out algorithm in which the site and level of SC activity both contribute to the computation of stimulus location is successful at evaluating the discrepant visual and auditory codes, and can account for subtle but systematic differences in the accuracy of auditory compared to visual saccades. This suggests that a given population of neurons can use different codes to support appropriate multimodal behavior. PMID:24454779

Digital administrative maps – A tool for visualization of epidemiological data

Directory of Open Access Journals (Sweden)

Ewa Niewiadomska

2013-08-01

Full Text Available Background: The aim of the study is to present the methods for visualization of epidemiological data using digital contour maps that take into account administrative division of Poland. Materials and Methods: The possibility of epidemiological data visualization in a geographical order, limited to the administrative level of the country, voivodeships and poviats (counties, are presented. They are crucial for the process of identifying and undertaking adequate prophylactic activities directed towards decreasing the risk and improving the population's health. This paper presents tools and techniques available in Geographic Information System ArcGIS and statistical software package R. Results: The work includes our own data reflecting: 1 the values of specific mortality rates due to respiratory diseases, Poland, 2010, based on the Central Statistical Office data, using the R statistical software package; 2 the averaged registered incidence rates of sarcoidosis in 2006-2010 for the population aged 19+ in the Silesian voivodeship, using Geographic Information System ArcGIS; and 3 the number of children with diagnosed respiratory diseases in the city of Legnica in 2009, taking into account their place of residence, using layered maps in Geographic Information System ArcGIS. Conclusions: The tools presented and described in this paper make it possible to visualize the results of research, to increase attractiveness of courses for students, as well as to enhance the skills and competence of students and participants of courses. Med Pr 2013;64(4:533–539

Mapping innovation processes: Visual techniques for opening and presenting the black box of service innovation processes

DEFF Research Database (Denmark)

Olesen, Anne Rørbæk

2017-01-01

This chapter argues for the usefulness of visual mapping techniques for performing qualitative analysis of complex service innovation processes. Different mapping formats are presented, namely, matrices, networks, process maps, situational analysis maps and temporal situational analysis maps....... For the purpose of researching service innovation processes, the three latter formats are argued to be particularly interesting. Process maps can give an overview of different periods and milestones in a process in one carefully organized location. Situational analysis maps and temporal situational analysis maps...... can open up complexities of service innovation processes, as well as close them down for presentational purposes. The mapping formats presented are illustrated by displaying maps from an exemplary research project, and the chapter is concluded with a brief discussion of the limitations and pitfalls...

Web mapping system for complex processing and visualization of environmental geospatial datasets

Science.gov (United States)

Titov, Alexander; Gordov, Evgeny; Okladnikov, Igor

2016-04-01

Environmental geospatial datasets (meteorological observations, modeling and reanalysis results, etc.) are used in numerous research applications. Due to a number of objective reasons such as inherent heterogeneity of environmental datasets, big dataset volume, complexity of data models used, syntactic and semantic differences that complicate creation and use of unified terminology, the development of environmental geodata access, processing and visualization services as well as client applications turns out to be quite a sophisticated task. According to general INSPIRE requirements to data visualization geoportal web applications have to provide such standard functionality as data overview, image navigation, scrolling, scaling and graphical overlay, displaying map legends and corresponding metadata information. It should be noted that modern web mapping systems as integrated geoportal applications are developed based on the SOA and might be considered as complexes of interconnected software tools for working with geospatial data. In the report a complex web mapping system including GIS web client and corresponding OGC services for working with geospatial (NetCDF, PostGIS) dataset archive is presented. There are three basic tiers of the GIS web client in it: 1. Tier of geospatial metadata retrieved from central MySQL repository and represented in JSON format 2. Tier of JavaScript objects implementing methods handling: --- NetCDF metadata --- Task XML object for configuring user calculations, input and output formats --- OGC WMS/WFS cartographical services 3. Graphical user interface (GUI) tier representing JavaScript objects realizing web application business logic Metadata tier consists of a number of JSON objects containing technical information describing geospatial datasets (such as spatio-temporal resolution, meteorological parameters, valid processing methods, etc). The middleware tier of JavaScript objects implementing methods for handling geospatial

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity.

Science.gov (United States)

Al-Awami, Ali K; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W; Pfister, Hanspeter; Hadwiger, Markus

2014-12-01

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

KAUST Repository

Al-Awami, Ali K.; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W.; Pfister, Hanspeter; Hadwiger, Markus

2014-01-01

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

KAUST Repository

Al-Awami, Ali K.

2014-12-31

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

Testing geoscience data visualization systems for geological mapping and training

Science.gov (United States)

Head, J. W.; Huffman, J. N.; Forsberg, A. S.; Hurwitz, D. M.; Basilevsky, A. T.; Ivanov, M. A.; Dickson, J. L.; Senthil Kumar, P.

2008-09-01

Traditional methods of planetary geological mapping have relied on photographic hard copy and light-table tracing and mapping. In the last several decades this has given way to the availability and analysis of multiple digital data sets, and programs and platforms that permit the viewing and manipulation of multiple annotated layers of relevant information. This has revolutionized the ability to incorporate important new data into the planetary mapping process at all scales. Information on these developments and approaches can be obtained at http://astrogeology.usgs. gov/ Technology/. The processes is aided by Geographic Information Systems (GIS) (see http://astrogeology. usgs.gov/Technology/) and excellent analysis packages (such as ArcGIS) that permit co-registration, rapid viewing, and analysis of multiple data sets on desktop displays (see http://astrogeology.usgs.gov/Projects/ webgis/). We are currently investigating new technological developments in computer visualization and analysis in order to assess their importance and utility in planetary geological analysis and mapping. Last year we reported on the range of technologies available and on our application of these to various problems in planetary mapping. In this contribution we focus on the application of these techniques and tools to Venus geological mapping at the 1:5M quadrangle scale. In our current Venus mapping projects we have utilized and tested the various platforms to understand their capabilities and assess their usefulness in defining units, establishing stratigraphic relationships, mapping structures, reaching consensus on interpretations and producing map products. We are specifically assessing how computer visualization display qualities (e.g., level of immersion, stereoscopic vs. monoscopic viewing, field of view, large vs. small display size, etc.) influence performance on scientific analysis and geological mapping. We have been exploring four different environments: 1) conventional

Mapping of Mechanical Strains and Stresses around Quiescent Engineered Three-Dimensional Epithelial Tissues

Science.gov (United States)

Gjorevski, Nikolce; Nelson, Celeste M.

2012-01-01

Understanding how physical signals guide biological processes requires qualitative and quantitative knowledge of the mechanical forces generated and sensed by cells in a physiologically realistic three-dimensional (3D) context. Here, we used computational modeling and engineered epithelial tissues of precise geometry to define the experimental parameters that are required to measure directly the mechanical stress profile of 3D tissues embedded within native type I collagen. We found that to calculate the stresses accurately in these settings, we had to account for mechanical heterogeneities within the matrix, which we visualized and quantified using confocal reflectance and atomic force microscopy. Using this technique, we were able to obtain traction forces at the epithelium-matrix interface, and to resolve and quantify patterns of mechanical stress throughout the surrounding matrix. We discovered that whereas single cells generate tension by contracting and pulling on the matrix, the contraction of multicellular tissues can also push against the matrix, causing emergent compression. Furthermore, tissue geometry defines the spatial distribution of mechanical stress across the epithelium, which communicates mechanically over distances spanning hundreds of micrometers. Spatially resolved mechanical maps can provide insight into the types and magnitudes of physical parameters that are sensed and interpreted by multicellular tissues during normal and pathological processes. PMID:22828342

SBGNViz: A Tool for Visualization and Complexity Management of SBGN Process Description Maps.

Directory of Open Access Journals (Sweden)

Mecit Sari

Full Text Available Information about cellular processes and pathways is becoming increasingly available in detailed, computable standard formats such as BioPAX and SBGN. Effective visualization of this information is a key recurring requirement for biological data analysis, especially for -omic data. Biological data analysis is rapidly migrating to web based platforms; thus there is a substantial need for sophisticated web based pathway viewers that support these platforms and other use cases.Towards this goal, we developed a web based viewer named SBGNViz for process description maps in SBGN (SBGN-PD. SBGNViz can visualize both BioPAX and SBGN formats. Unique features of SBGNViz include the ability to nest nodes to arbitrary depths to represent molecular complexes and cellular locations, automatic pathway layout, editing and highlighting facilities to enable focus on sub-maps, and the ability to inspect pathway members for detailed information from EntrezGene. SBGNViz can be used within a web browser without any installation and can be readily embedded into web pages. SBGNViz has two editions built with ActionScript and JavaScript. The JavaScript edition, which also works on touch enabled devices, introduces novel methods for managing and reducing complexity of large SBGN-PD maps for more effective analysis.SBGNViz fills an important gap by making the large and fast-growing corpus of rich pathway information accessible to web based platforms. SBGNViz can be used in a variety of contexts and in multiple scenarios ranging from visualization of the results of a single study in a web page to building data analysis platforms.

Multiscale visual quality assessment for cluster analysis with self-organizing maps

Science.gov (United States)

Bernard, Jürgen; von Landesberger, Tatiana; Bremm, Sebastian; Schreck, Tobias

2011-01-01

Cluster analysis is an important data mining technique for analyzing large amounts of data, reducing many objects to a limited number of clusters. Cluster visualization techniques aim at supporting the user in better understanding the characteristics and relationships among the found clusters. While promising approaches to visual cluster analysis already exist, these usually fall short of incorporating the quality of the obtained clustering results. However, due to the nature of the clustering process, quality plays an important aspect, as for most practical data sets, typically many different clusterings are possible. Being aware of clustering quality is important to judge the expressiveness of a given cluster visualization, or to adjust the clustering process with refined parameters, among others. In this work, we present an encompassing suite of visual tools for quality assessment of an important visual cluster algorithm, namely, the Self-Organizing Map (SOM) technique. We define, measure, and visualize the notion of SOM cluster quality along a hierarchy of cluster abstractions. The quality abstractions range from simple scalar-valued quality scores up to the structural comparison of a given SOM clustering with output of additional supportive clustering methods. The suite of methods allows the user to assess the SOM quality on the appropriate abstraction level, and arrive at improved clustering results. We implement our tools in an integrated system, apply it on experimental data sets, and show its applicability.

Constellation Map: Downstream visualization and interpretation of gene set enrichment results [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Yan Tan

2015-06-01

Full Text Available Summary: Gene set enrichment analysis (GSEA approaches are widely used to identify coordinately regulated genes associated with phenotypes of interest. Here, we present Constellation Map, a tool to visualize and interpret the results when enrichment analyses yield a long list of significantly enriched gene sets. Constellation Map identifies commonalities that explain the enrichment of multiple top-scoring gene sets and maps the relationships between them. Constellation Map can help investigators take full advantage of GSEA and facilitates the biological interpretation of enrichment results. Availability: Constellation Map is freely available as a GenePattern module at http://www.genepattern.org.

On Mathematical Optimization for the Visualization of Frequencies and Adjacencies as Rectangular Maps

DEFF Research Database (Denmark)

Carrizosa, Emilio; Guerrero, Vanesa; Morales, Dolores Romero

2018-01-01

individuals as adjacent rectangular portions as possible and adding as few false adjacencies, i.e., adjacencies between rectangular portions corresponding to non-adjacent individuals, as possible. We formulate this visualization problem as a Mixed Integer Linear Programming (MILP) model. We propose......In this paper we address the problem of visualizing a frequency distribution and an adjacency relation attached to a set of individuals. We represent this information using a rectangular map, i.e., a subdivision of a rectangle into rectangular portions so that each portion is associated with one...

A visualization environment for supercomputing-based applications in computational mechanics

Energy Technology Data Exchange (ETDEWEB)

Pavlakos, C.J.; Schoof, L.A.; Mareda, J.F.

1993-06-01

In this paper, we characterize a visualization environment that has been designed and prototyped for a large community of scientists and engineers, with an emphasis in superconducting-based computational mechanics. The proposed environment makes use of a visualization server concept to provide effective, interactive visualization to the user`s desktop. Benefits of using the visualization server approach are discussed. Some thoughts regarding desirable features for visualization server hardware architectures are also addressed. A brief discussion of the software environment is included. The paper concludes by summarizing certain observations which we have made regarding the implementation of such visualization environments.

Mapping and Visualization of The Deepwater Horizon Oil Spill Using Satellite Imagery

Science.gov (United States)

Ferreira Pichardo, E.

2017-12-01

Satellites are man-made objects hovering around the Earth's orbit and are essential for Earth observation, i.e. the monitoring and gathering of data about the Earth's vital systems. Environmental Satellites are used for atmospheric research, weather forecasting, and warning as well as monitoring extreme weather events. These satellites are categorized into Geosynchronous and Low Earth (Polar) orbiting satellites. Visualizing satellite data is critical to understand the Earth's systems and changes to our environment. The objective of this research is to examine satellite-based remotely sensed data that needs to be processed and rendered in the form of maps or other forms of visualization to understand and interpret the satellites' observations to monitor the status, changes and evolution of the mega-disaster Deepwater Horizon Spill that occurred on April 20, 2010 in the Gulf of Mexico. In this project, we will use an array of tools and programs such as Python, CSPP and Linux. Also, we will use data from the National Oceanic and Atmospheric Administration (NOAA): Polar-Orbiting Satellites Terra Earth Observing System AM-1 (EOS AM-1), and Aqua EOS PM-1 to investigate the mega-disaster. Each of these satellites carry a variety of instruments, and we will use the data obtained from the remote sensor Moderate-Resolution Imaging Spectroradiometer (MODIS). Ultimately, this study shows the importance of mapping and visualizing data such as satellite data (MODIS) to understand the extents of environmental impacts disasters such as the Deepwater Horizon Oil spill.

Personal sleep pattern visualization using sequence-based kernel self-organizing map on sound data.

Science.gov (United States)

Wu, Hongle; Kato, Takafumi; Yamada, Tomomi; Numao, Masayuki; Fukui, Ken-Ichi

2017-07-01

We propose a method to discover sleep patterns via clustering of sound events recorded during sleep. The proposed method extends the conventional self-organizing map algorithm by kernelization and sequence-based technologies to obtain a fine-grained map that visualizes the distribution and changes of sleep-related events. We introduced features widely applied in sound processing and popular kernel functions to the proposed method to evaluate and compare performance. The proposed method provides a new aspect of sleep monitoring because the results demonstrate that sound events can be directly correlated to an individual's sleep patterns. In addition, by visualizing the transition of cluster dynamics, sleep-related sound events were found to relate to the various stages of sleep. Therefore, these results empirically warrant future study into the assessment of personal sleep quality using sound data. Copyright © 2017 Elsevier B.V. All rights reserved.

Visual thread quality for precision miniature mechanisms

Energy Technology Data Exchange (ETDEWEB)

Gillespie, L.K.

1981-04-01

Threaded features have eight visual appearance factors which can affect their function in precision miniature mechanisms. The Bendix practice in deburring, finishing, and accepting these conditions on miniature threads is described as is their impact in assemblies of precision miniature electromechanical assemblies.

Uvmas: Venus Ultraviolet-visual Mapping Spectrometer

Science.gov (United States)

Bellucci, G.; Zasova, L.; Altieri, F.; Formisano, V.; Ignatiev, N.; Moroz, V.

We present the concept of an instrument for remote sensing of Venus from a planetary orbiter. The main characteristics of the instrument are the following: A~é· Spectral range: 0.190 A~é­ 0.490 A~éµm A~é· Spectral resolution: 0.4 nm (/= 500 at 0.2 A~éµ m) A~é· Angular resolution: 0.4 mrad at max A~é· Spatial resolution: 200 meters at 500 Km A~é· Field of view = 5.7A~é° A~é· S/N: 70 at 0.2 A~éµ m at 1 sec exp time given albedo = 0.03. The scientific objectives are the following: Dynamic investigation (0.2 5 µm). Mapping facility will allow the tracking of the UV features and will define the velocities in the atmosphere near the cloud top level. Detailed mapping of velocities of UV features at high spatial resolution, their variation with latitude, altitude and local time will advance our knowledge in understanding the puzzles of Venus dynamics like how and what mechanism drives the Venus atmospheric mass from equator to pole against temperature gradient and what is the mechanism supporting the zonal superrotation. What is the polar vortex organization, at what latitudes there is the descending branch of the Hadley cell. SO2 and SO in the range 0.232 µm. In this spectral range the SO2 and SO bands are observed. They present unresolved features with 10 Å width. Vertical profiles of these components may be obtained above the cloud and below the upper cloud boundary. Vertical, horizontal, local time and temporal variation will be obtained. This allows to create a photochemical model of the atmosphere above the clouds, and to understand a mechanism of cloud aerosol formation. "Unknown" UV- absorber, in the range 0.3 5 µm. It absorbs 50 % of the solar energy deposited on Venus. It exists only in the upper clouds. It is not known if it is in gaseous phase or included in the aerosol particles. This absorber is not homogeneously distributed and is responsible for the UV atmospheric contrast from 0.32­0.5 µm; it correlates

The Effects of Knowledge Maps on Acquisition and Retention of Visual Arts Concepts in Teacher Education

Directory of Open Access Journals (Sweden)

Paige Vitulli

2014-01-01

Full Text Available This study examined the use of knowledge maps as a tool for teacher education students to increase knowledge acquisition and retention of concepts related to the visual arts design elements: line, color, and shape. Participants were randomly assigned to either the no map or knowledge map group. Three instruments—Student Autobiography, Elements of Design Tests (EDT, and Knowledge Map Questionnaire—were used to collect data. Results revealed significantly higher means on the immediately administered posttest for the elements line and color and the delayed posttest for line map group. Questionnaire responses indicated positive attitudes toward knowledge map use as a study strategy. Specifically, endorsement was reported toward maps’ clarity, effectiveness for learning concepts, and enjoyment of use.

Perceptual Dependencies in Information Visualization Assessed by Complex Visual Search

NARCIS (Netherlands)

Berg, Ronald van den; Cornelissen, Frans W.; Roerdink, Jos B.T.M.

A common approach for visualizing data sets is to map them to images in which distinct data dimensions are mapped to distinct visual features, such as color, size and orientation. Here, we consider visualizations in which different data dimensions should receive equal weight and attention. Many of

Visual Analysis Based on the Data of Chinese Surveying and Mapping Journals

Science.gov (United States)

Li, Jing; Liu, Haiyan; Guo, Wenyue; Yu, Anzhu

2016-06-01

Taking four influential Chinese surveying and mapping journals as the data source, 5863 papers published during the period of 2003-2013 were obtained. Using the method of bibliometrics and visual analysis, summarizing the surveying and mapping papers in the past ten years (2003-2013), research themes, authors, and geographical distribution were analyzed. In the study, the papers of geodesy, cartography and GIS are 59.9%, more than half of all the papers. We also determine that the core author group has 131 authors, mainly of whom are from big cities. 90% of top ten cities on the number of publishing papers are capital cities or municipalities directly under the central government.In conclusion, we found that the research focus was different every year, and the research content was richness, the content of geodesy, cartography and GIS were widely researched, and the development of surveying and mapping is imbalanced in China.

INTEGRATION ASPECTS OF THE LANGUAGE OF THE MAP IN THE VISUALIZATION OF INFORMATION IN THE INTERNET ERA

Directory of Open Access Journals (Sweden)

A. K. Suvorov

2014-01-01

Full Text Available Development of new principles of the language maps associated with the use of the Internet, computers and mobile devices. It is shown that the mapping in the modern society with the use of the Internet is based on ready-made visual images of reality, realization of creative opportunities of people by manipulating these images, posting on the Internet of personal information, implementation of project, mapping and other works on the remote services using Web connection. Describes the developed by the author hermeneutic principles of mapping.

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…

Open Touch/Sound Maps: A system to convey street data through haptic and auditory feedback

Science.gov (United States)

Kaklanis, Nikolaos; Votis, Konstantinos; Tzovaras, Dimitrios

2013-08-01

The use of spatial (geographic) information is becoming ever more central and pervasive in today's internet society but the most of it is currently inaccessible to visually impaired users. However, access in visual maps is severely restricted to visually impaired and people with blindness, due to their inability to interpret graphical information. Thus, alternative ways of a map's presentation have to be explored, in order to enforce the accessibility of maps. Multiple types of sensory perception like touch and hearing may work as a substitute of vision for the exploration of maps. The use of multimodal virtual environments seems to be a promising alternative for people with visual impairments. The present paper introduces a tool for automatic multimodal map generation having haptic and audio feedback using OpenStreetMap data. For a desired map area, an elevation map is being automatically generated and can be explored by touch, using a haptic device. A sonification and a text-to-speech (TTS) mechanism provide also audio navigation information during the haptic exploration of the map.

Constructing visual representations

DEFF Research Database (Denmark)

Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh

2014-01-01

tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants’ actions during the development of their visual representations......The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings......, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only...

GeoMapApp as a platform for visualizing marine data from Polar Regions

Science.gov (United States)

Nitsche, F. O.; Ryan, W. B.; Carbotte, S. M.; Ferrini, V.; Goodwillie, A. M.; O'hara, S. H.; Weissel, R.; McLain, K.; Chinhong, C.; Arko, R. A.; Chan, S.; Morton, J. J.; Pomeroy, D.

2012-12-01

To maximize the investment in expensive fieldwork the resulting data should be re-used as much as possible. In addition, unnecessary duplication of data collection effort should be avoided. This becomes even more important if access to field areas is as difficult and expensive as it is in Polar Regions. Making existing data discoverable in an easy to use platform is key to improve re-use and avoid duplication. A common obstacle is that use of existing data is often limited to specialists who know of the data existence and also have the right tools to view and analyze these data. GeoMapApp is a free, interactive, map based tool that allows users to discover, visualize, and analyze a large number of data sets. In addition to a global view, it provides polar map projections for displaying data in Arctic and Antarctic areas. Data that have currently been added to the system include Arctic swath bathymetry data collected from the USCG icebreaker Healy. These data are collected almost continuously including from cruises where bathymetry is not the main objective and for which existence of the acquired data may not be well known. In contrast, existence of seismic data from the Antarctic continental margin is well known in the seismic community. They are archived at and can be accessed through the Antarctic Seismic Data Library System (SDLS). Incorporating these data into GeoMapApp makes an even broader community aware of these data and the custom interface, which includes capabilities to visualize and explore these data, allows users without specific software or knowledge of the underlying data format to access the data. In addition to investigating these datasets, GeoMapApp provides links to the actual data sources to allow specialists the opportunity to re-use the original data. Important identification of data sources and data references are achieved on different levels. For access to the actual Antarctic seismic data GeoMapApp links to the SDLS site, where users have

Map making and map use in a multi-actor context : Spatial visualizations and frame conflicts in regional policymaking in the Netherlands

NARCIS (Netherlands)

Carton, L.J.

2007-01-01

In this thesis, the practice of map-making and map use is studied among actors involved in spatial planning and water management. The socio-technical mechanisms between knowlegde production and policymaking in Dutch regional planning make up the central object of study, with map images as observable

Velocity Mapping Toolbox (VMT): a processing and visualization suite for moving-vessel ADCP measurements

Science.gov (United States)

Parsons, D.R.; Jackson, P.R.; Czuba, J.A.; Engel, F.L.; Rhoads, B.L.; Oberg, K.A.; Best, J.L.; Mueller, D.S.; Johnson, K.K.; Riley, J.D.

2013-01-01

The use of acoustic Doppler current profilers (ADCP) for discharge measurements and three-dimensional flow mapping has increased rapidly in recent years and has been primarily driven by advances in acoustic technology and signal processing. Recent research has developed a variety of methods for processing data obtained from a range of ADCP deployments and this paper builds on this progress by describing new software for processing and visualizing ADCP data collected along transects in rivers or other bodies of water. The new utility, the Velocity Mapping Toolbox (VMT), allows rapid processing (vector rotation, projection, averaging and smoothing), visualization (planform and cross-section vector and contouring), and analysis of a range of ADCP-derived datasets. The paper documents the data processing routines in the toolbox and presents a set of diverse examples that demonstrate its capabilities. The toolbox is applicable to the analysis of ADCP data collected in a wide range of aquatic environments and is made available as open-source code along with this publication.

Open Knowledge Maps: Creating a Visual Interface to the World’s Scientific Knowledge Based on Natural Language Processing

Directory of Open Access Journals (Sweden)

Peter Kraker

2016-11-01

Full Text Available The goal of Open Knowledge Maps is to create a visual interface to the world’s scientific knowledge. The base for this visual interface consists of so-called knowledge maps, which enable the exploration of existing knowledge and the discovery of new knowledge. Our open source knowledge mapping software applies a mixture of summarization techniques and similarity measures on article metadata, which are iteratively chained together. After processing, the representation is saved in a database for use in a web visualization. In the future, we want to create a space for collective knowledge mapping that brings together individuals and communities involved in exploration and discovery. We want to enable people to guide each other in their discovery by collaboratively annotating and modifying the automatically created maps. Das Ziel von Open Knowledge Map ist es, ein visuelles Interface zum wissenschaftlichen Wissen der Welt bereitzustellen. Die Basis für die dieses Interface sind sogenannte “knowledge maps”, zu deutsch Wissenslandkarten. Wissenslandkarten ermöglichen die Exploration bestehenden Wissens und die Entdeckung neuen Wissens. Unsere Open Source Software wendet für die Erstellung der Wissenslandkarten eine Reihe von Text Mining Verfahren iterativ auf die Metadaten wissenschaftlicher Artikel an. Die daraus resultierende Repräsentation wird in einer Datenbank für die Anzeige in einer Web-Visualisierung abgespeichert. In Zukunft wollen wir einen Raum für das kollektive Erstellen von Wissenslandkarten schaffen, der die Personen und Communities, welche sich mit der Exploration und Entdeckung wissenschaftlichen Wissens beschäftigen, zusammenbringt. Wir wollen es den NutzerInnen ermöglichen, einander in der Literatursuche durch kollaboratives Annotieren und Modifizieren von automatisch erstellten Wissenslandkarten zu unterstützen.

Expanding Thurston maps

CERN Document Server

Bonk, Mario

2017-01-01

This monograph is devoted to the study of the dynamics of expanding Thurston maps under iteration. A Thurston map is a branched covering map on a two-dimensional topological sphere such that each critical point of the map has a finite orbit under iteration. It is called expanding if, roughly speaking, preimages of a fine open cover of the underlying sphere under iterates of the map become finer and finer as the order of the iterate increases. Every expanding Thurston map gives rise to a fractal space, called its visual sphere. Many dynamical properties of the map are encoded in the geometry of this visual sphere. For example, an expanding Thurston map is topologically conjugate to a rational map if and only if its visual sphere is quasisymmetrically equivalent to the Riemann sphere. This relation between dynamics and fractal geometry is the main focus for the investigations in this work.

Visual acuity and microperimetric mapping of lesion area in eyes with inflammatory cystoid macular oedema

DEFF Research Database (Denmark)

Munk, Marion R; Kiss, Christopher G; Huf, Wolfgang

2014-01-01

PURPOSE:   To evaluate the effect of fluid accumulation on local visual function in inflammatory cystoid-macular-edema (ICME). METHODS:   This cross-sectional study applied optical-coherence-tomography over a 12×12 fovea-centered field in 50 patients with ICME and mapped the extent of fluid-fille...... retinal layers also had major impact on both of these two functional parameters. Visual-impairment seems to differ depending on the layers involved, thus different types of fluid accumulation may potentially be given varying treatment priorities....

Model Interpretation of Topological Spatial Analysis for the Visually Impaired (Blind Implemented in Google Maps

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Marcelo Franco Porto

2013-06-01

Full Text Available The technological innovations promote the availability of geographic information on the Internet through Web GIS such as Google Earth and Google Maps. These systems contribute to the teaching and diffusion of geographical knowledge that instigates the recognition of the space we live in, leading to the creation of a spatial identity. In these products available on the Web, the interpretation and analysis of spatial information gives priority to one of the human senses: vision. Due to the fact that this representation of information is transmitted visually (image and vectors, a portion of the population is excluded from part of this knowledge because categories of analysis of geographic data such as borders, territory, and space can only be understood by people who can see. This paper deals with the development of a model of interpretation of topological spatial analysis based on the synthesis of voice and sounds that can be used by the visually impaired (blind.The implementation of a prototype in Google Maps and the usability tests performed are also examined. For the development work it was necessary to define the model of topological spatial analysis, focusing on computational implementation, which allows users to interpret the spatial relationships of regions (countries, states and municipalities, recognizing its limits, neighborhoods and extension beyond their own spatial relationships . With this goal in mind, several interface and usability guidelines were drawn up to be used by the visually impaired (blind. We conducted a detailed study of the Google Maps API (Application Programming Interface, which was the environment selected for prototype development, and studied the information available for the users of that system. The prototype was developed based on the synthesis of voice and sounds that implement the proposed model in C # language and in .NET environment. To measure the efficiency and effectiveness of the prototype, usability

Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

Science.gov (United States)

Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

2011-08-01

Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e., brightness and contrast in low-level stimulus features. Here we review this approach and present new data from our own experiments with an agnosic patient that quantifies the relationship between saliency and fixation location. In addition, we consider whether the perceptual difficulties of individual patients might be modeled by selectively weighting the different features involved in a saliency map. Our data indicate that saliency is not always a good predictor of fixation in agnosia: even for our agnosic subject, as for normal observers, the saliency-fixation relationship varied as a function of the task. This means that top-down processes still have a significant effect on the earliest stages of scanning in the setting of visual agnosia, indicating severe limitations for the saliency map model. Top-down, active strategies-which are the hallmark of our human visual system-play a vital role in eye movement control, whether we know what we are looking at or not. Copyright © 2011 Elsevier Ltd. All rights reserved.

The mapping of the visual field onto the dorso-lateral tectum of the pigeon (Columba livia) and its relations with retinal specializations.

Science.gov (United States)

Letelier, Juan-Carlos; Marin, Gonzalo; Sentis, Elisa; Tenreiro, Andrea; Fredes, Felipe; Mpodozis, Jorge

2004-01-30

Most of the physiological studies of the pigeon retino-tectal visual pathway have investigated the accessible tectum, a small dorso-lateral tectal section that can be easily accessed by a simple craniotomy. However, at present we lack a detailed study of the topographical arrangement between the visual field, the retina and the accessible tectum. In particular, it is not known which section of the visual field is mapped onto the accessible tectum, and which of the specialized retinal areas mediates this projection. Here we determined, using local field potential (LFP) recordings and reverse retinoscopy, the shape, size and position in the visual space of the portion of the visual field mapped onto the accessible tectum (called here the accessible visual field, or AVF). Using this data and the mapping of Nalbach et al. [Vis. Res. 30 (4) (1990) 529], the retinal area corresponding to the AVF was determined. Such retinal area was also directly delimited by means of retrograde transport of DiI. The results indicate that the AVF is a triangular perifoveal zone encompassing only 15% of total visual field. The retinal region corresponding to the AVF has the shape of an elongated triangle that runs parallel to the visual equator and contains the fovea, the tip of the pecten, a perifoveal region of the yellow field and a small crescent of the red field. In agreement with this anatomical heterogeneity, visual evoked potentials measured in different parts of the accessible tectum present steep variations in shape and size. These results are helpful to better design and interpret anatomical and physiological experiments involving the pigeon's visual system.

Visualization of Nonlinear Classification Models in Neuroimaging - Signed Sensitivity Maps

DEFF Research Database (Denmark)

Rasmussen, Peter Mondrup; Schmah, Tanya; Madsen, Kristoffer Hougaard

2012-01-01

Classification models are becoming increasing popular tools in the analysis of neuroimaging data sets. Besides obtaining good prediction accuracy, a competing goal is to interpret how the classifier works. From a neuroscientific perspective, we are interested in the brain pattern reflecting...... the underlying neural encoding of an experiment defining multiple brain states. In this relation there is a great desire for the researcher to generate brain maps, that highlight brain locations of importance to the classifiers decisions. Based on sensitivity analysis, we develop further procedures for model...... direction the individual locations influence the classification. We illustrate the visualization procedure on a real data from a simple functional magnetic resonance imaging experiment....

Intermittently-visual Tracking Experiments Reveal the Roles of Error-correction and Predictive Mechanisms in the Human Visual-motor Control System

Science.gov (United States)

Hayashi, Yoshikatsu; Tamura, Yurie; Sase, Kazuya; Sugawara, Ken; Sawada, Yasuji

Prediction mechanism is necessary for human visual motion to compensate a delay of sensory-motor system. In a previous study, “proactive control” was discussed as one example of predictive function of human beings, in which motion of hands preceded the virtual moving target in visual tracking experiments. To study the roles of the positional-error correction mechanism and the prediction mechanism, we carried out an intermittently-visual tracking experiment where a circular orbit is segmented into the target-visible regions and the target-invisible regions. Main results found in this research were following. A rhythmic component appeared in the tracer velocity when the target velocity was relatively high. The period of the rhythm in the brain obtained from environmental stimuli is shortened more than 10%. The shortening of the period of rhythm in the brain accelerates the hand motion as soon as the visual information is cut-off, and causes the precedence of hand motion to the target motion. Although the precedence of the hand in the blind region is reset by the environmental information when the target enters the visible region, the hand motion precedes the target in average when the predictive mechanism dominates the error-corrective mechanism.

SNPexp - A web tool for calculating and visualizing correlation between HapMap genotypes and gene expression levels

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Franke Andre

2010-12-01

Full Text Available Abstract Background Expression levels for 47294 transcripts in lymphoblastoid cell lines from all 270 HapMap phase II individuals, and genotypes (both HapMap phase II and III of 3.96 million single nucleotide polymorphisms (SNPs in the same individuals are publicly available. We aimed to generate a user-friendly web based tool for visualization of the correlation between SNP genotypes within a specified genomic region and a gene of interest, which is also well-known as an expression quantitative trait locus (eQTL analysis. Results SNPexp is implemented as a server-side script, and publicly available on this website: http://tinyurl.com/snpexp. Correlation between genotype and transcript expression levels are calculated by performing linear regression and the Wald test as implemented in PLINK and visualized using the UCSC Genome Browser. Validation of SNPexp using previously published eQTLs yielded comparable results. Conclusions SNPexp provides a convenient and platform-independent way to calculate and visualize the correlation between HapMap genotypes within a specified genetic region anywhere in the genome and gene expression levels. This allows for investigation of both cis and trans effects. The web interface and utilization of publicly available and widely used software resources makes it an attractive supplement to more advanced bioinformatic tools. For the advanced user the program can be used on a local computer on custom datasets.

Cardiac MRI. T2-mapping versus T2-weighted dark-blood TSE imaging for myocardial edema visualization in acute myocardial infarction

International Nuclear Information System (INIS)

Nassenstein, K.; Nensa, F.; Schlosser, T.; Umutlu, L.; Lauenstein, T.; Bruder, O.; Maderwald, S.; Ladd, M.E.

2014-01-01

Purpose: To assess the diagnostic accuracy of T2 mapping for the detection of myocardial edema in acute myocardial infarction (AMI), and to compare this diagnostic accuracy with that of the current standard for myocardial edema imaging, which is T2w dark-blood TSE imaging. Materials and Methods: 29 patients with AMI were examined at 1.5 T. For the visualization of myocardial edema, T2 maps, calculated from three T2w SSFP images, and T2w dark-blood TSE images were acquired in standard short- and long-axis views. Cine SSFP images were acquired for the analysis of left ventricular (LV) function and late gadolinium enhancement images (LGE) for the visualization of myocardial necrosis. The T2 maps as well as the T2w dark-blood TSE images were evaluated twice independently from the cine SSFP and LGE images. The presence or absence of myocardial edema was rated visually for each LV segment. As the standard of reference, the infarct zone was defined based on the cine SSFP and the LGE images. Results: In this segment-based analysis, T2 mapping showed a sensitivity of 82 % and a specificity of 94 % for the detection of edema in the infarct zone. T2w dark-blood TSE imaging revealed a sensitivity of 50 % and a specificity of 98 %. T2 mapping showed a higher intra-rater agreement compared to T2w dark-blood TSE imaging (κ: 0.87 vs. 0.76). Conclusions: T2 mapping allows for the visualization of myocardial edema in AMI with a high sensitivity and specificity, and features better diagnostic accuracy in terms of a higher sensitivity compared to T2w dark-blood TSE imaging. (orig.)

High-resolution Self-Organizing Maps for advanced visualization and dimension reduction.

Science.gov (United States)

Saraswati, Ayu; Nguyen, Van Tuc; Hagenbuchner, Markus; Tsoi, Ah Chung

2018-05-04

Kohonen's Self Organizing feature Map (SOM) provides an effective way to project high dimensional input features onto a low dimensional display space while preserving the topological relationships among the input features. Recent advances in algorithms that take advantages of modern computing hardware introduced the concept of high resolution SOMs (HRSOMs). This paper investigates the capabilities and applicability of the HRSOM as a visualization tool for cluster analysis and its suitabilities to serve as a pre-processor in ensemble learning models. The evaluation is conducted on a number of established benchmarks and real-world learning problems, namely, the policeman benchmark, two web spam detection problems, a network intrusion detection problem, and a malware detection problem. It is found that the visualization resulted from an HRSOM provides new insights concerning these learning problems. It is furthermore shown empirically that broad benefits from the use of HRSOMs in both clustering and classification problems can be expected. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vector model for mapping of visual space to subjective 4-D sphere

International Nuclear Information System (INIS)

Matuzevicius, Dalius; Vaitkevicius, Henrikas

2014-01-01

Here we present a mathematical model of binocular vision that maps a visible physical world to a subjective perception of it. The subjective space is a set of 4-D vectors whose components are outputs of four monocular neurons from each of the two eyes. Monocular neurons have one of the four types of concentric receptive fields with Gabor-like weighting coefficients. Next this vector representation of binocular vision is implemented as a pool of neurons where each of them is selective to the object's particular location in a 3-D visual space. Formally each point of the visual space is being projected onto a 4-D sphere. Proposed model allows determination of subjective distances in depth and direction, provides computational means for determination of Panum's area and explains diplopia and allelotropia

Direct Visualization of Mechanical Beats by Means of an Oscillating Smartphone

Science.gov (United States)

Giménez, Marcos H.; Salinas, Isabel; Monsoriu, Juan A.; Castro-Palacio, Juan C.

2017-10-01

The resonance phenomenon is widely known in physics courses. Qualitatively speaking, resonance takes place in a driven oscillating system whenever the frequency approaches the natural frequency, resulting in maximal oscillatory amplitude. Very closely related to resonance is the phenomenon of mechanical beating, which occurs when the driving and natural frequencies of the system are slightly different. The frequency of the beat is just the difference of the natural and driving frequencies. Beats are very familiar in acoustic systems. There are several works in this journal on visualizing the beats in acoustic systems. For instance, the microphone and the speaker of two mobile devices were used in previous work to analyze the acoustic beats produced by two signals of close frequencies. The formation of beats can also be visualized in mechanical systems, such as a mass-spring system or a double-driven string. Here, the mechanical beats in a smartphone-spring system are directly visualized in a simple way. The frequency of the beats is measured by means of the acceleration sensor of a smartphone, which hangs from a spring attached to a mechanical driver. This laboratory experiment is suitable for both high school and first-year university physics courses.

Modeling of the positioning system and visual mark-up of historical cadastral maps

Directory of Open Access Journals (Sweden)

Tomislav Jakopec

2013-03-01

Full Text Available The aim of the paper is to present of the possibilities of positioning and visual markup of historical cadastral maps onto Google maps using open source software. The corpus is stored in the Croatian State Archives in Zagreb, in the Maps Archive for Croatia and Slavonia. It is part of cadastral documentation that consists of cadastral material from the period of first cadastral survey conducted in the Kingdom of Croatia and Slavonia from 1847 to 1877, and which is used extensively according to the data provided by the customer service of the Croatian State Archives. User needs on the one side and the possibilities of innovative implementation of ICT on the other have motivated the development of the system which would use digital copies of original cadastral maps and connect them with systems like Google maps, and thus both protect the original materials and open up new avenues of research related to the use of originals. With this aim in mind, two cadastral map presentation models have been created. Firstly, there is a detailed display of the original, which enables its viewing using dynamic zooming. Secondly, the interactive display is facilitated through blending the cadastral maps with Google maps, which resulted in establishing links between the coordinates of the digital and original plans through transformation. The transparency of the original can be changed, and the user can intensify the visibility of the underlying layer (Google map or the top layer (cadastral map, which enables direct insight into parcel dynamics over a longer time-span. The system also allows for the mark-up of cadastral maps, which can lead to the development of the cumulative index of all terms found on cadastral maps. The paper is an example of the implementation of ICT for providing new services, strengthening cooperation with the interested public and related institutions, familiarizing the public with the archival material, and offering new possibilities for

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

Energy Technology Data Exchange (ETDEWEB)

Shaw, Adam; Nunn, John, E-mail: adam.shaw@npl.co.u [National Physical Laboratory, Teddington, Middlesex, TW11 0LW (United Kingdom)

2010-06-07

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45{sup 0} to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 {sup 0}C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible. (note)

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

International Nuclear Information System (INIS)

Shaw, Adam; Nunn, John

2010-01-01

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45 0 to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 0 C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible. (note)

Mapping and characterization of positive and negative BOLD responses to visual stimulation in multiple brain regions at 7T.

Science.gov (United States)

Jorge, João; Figueiredo, Patrícia; Gruetter, Rolf; van der Zwaag, Wietske

2018-02-20

External stimuli and tasks often elicit negative BOLD responses in various brain regions, and growing experimental evidence supports that these phenomena are functionally meaningful. In this work, the high sensitivity available at 7T was explored to map and characterize both positive (PBRs) and negative BOLD responses (NBRs) to visual checkerboard stimulation, occurring in various brain regions within and beyond the visual cortex. Recently-proposed accelerated fMRI techniques were employed for data acquisition, and procedures for exclusion of large draining vein contributions, together with ICA-assisted denoising, were included in the analysis to improve response estimation. Besides the visual cortex, significant PBRs were found in the lateral geniculate nucleus and superior colliculus, as well as the pre-central sulcus; in these regions, response durations increased monotonically with stimulus duration, in tight covariation with the visual PBR duration. Significant NBRs were found in the visual cortex, auditory cortex, default-mode network (DMN) and superior parietal lobule; NBR durations also tended to increase with stimulus duration, but were significantly less sustained than the visual PBR, especially for the DMN and superior parietal lobule. Responses in visual and auditory cortex were further studied for checkerboard contrast dependence, and their amplitudes were found to increase monotonically with contrast, linearly correlated with the visual PBR amplitude. Overall, these findings suggest the presence of dynamic neuronal interactions across multiple brain regions, sensitive to stimulus intensity and duration, and demonstrate the richness of information obtainable when jointly mapping positive and negative BOLD responses at a whole-brain scale, with ultra-high field fMRI. © 2018 Wiley Periodicals, Inc.

MARs Tools for Interactive ANalysis (MARTIAN): Google Maps Tools for Visual Exploration of Geophysical Modeling on Mars

Science.gov (United States)

Dimitrova, L. L.; Haines, M.; Holt, W. E.; Schultz, R. A.; Richard, G.; Haines, A. J.

2006-12-01

Interactive maps of surface-breaking faults and stress models on Mars provide important tools to engage undergraduate students, educators, and scientists with current geological and geophysical research. We have developed a map based on the Google Maps API -- an Internet based tool combining DHTML and AJAX, -- which allows very large maps to be viewed over the World Wide Web. Typically, small portions of the maps are downloaded as needed, rather than the entire image at once. This set-up enables relatively fast access for users with low bandwidth. Furthermore, Google Maps provides an extensible interactive interface making it ideal for visualizing multiple data sets at the user's choice. The Google Maps API works primarily with data referenced to latitudes and longitudes, which is then mapped in Mercator projection only. We have developed utilities for general cylindrical coordinate systems by converting these coordinates into equivalent Mercator projection before including them on the map. The MARTIAN project is available at http://rock.geo.sunysb.edu/~holt/Mars/MARTIAN/. We begin with an introduction to the Martian surface using a topography model. Faults from several datasets are classified by type (extension vs. compression) and by time epoch. Deviatoric stresses due to gravitational potential energy differences, calculated from the topography and crustal thickness, can be overlain. Several quantitative measures for the fit of the stress field to the faults are also included. We provide introductory text and exercises spanning a range of topics: how are faults identified, what stress is and how it relates to faults, what gravitational potential energy is and how variations in it produce stress, how the models are created, and how these models can be evaluated and interpreted. The MARTIAN tool is used at Stony Brook University in GEO 310: Introduction to Geophysics, a class geared towards junior and senior geosciences majors. Although this project is in its

Fast and robust generation of feature maps for region-based visual attention.

Science.gov (United States)

Aziz, Muhammad Zaheer; Mertsching, Bärbel

2008-05-01

Visual attention is one of the important phenomena in biological vision which can be followed to achieve more efficiency, intelligence, and robustness in artificial vision systems. This paper investigates a region-based approach that performs pixel clustering prior to the processes of attention in contrast to late clustering as done by contemporary methods. The foundation steps of feature map construction for the region-based attention model are proposed here. The color contrast map is generated based upon the extended findings from the color theory, the symmetry map is constructed using a novel scanning-based method, and a new algorithm is proposed to compute a size contrast map as a formal feature channel. Eccentricity and orientation are computed using the moments of obtained regions and then saliency is evaluated using the rarity criteria. The efficient design of the proposed algorithms allows incorporating five feature channels while maintaining a processing rate of multiple frames per second. Another salient advantage over the existing techniques is the reusability of the salient regions in the high-level machine vision procedures due to preservation of their shapes and precise locations. The results indicate that the proposed model has the potential to efficiently integrate the phenomenon of attention into the main stream of machine vision and systems with restricted computing resources such as mobile robots can benefit from its advantages.

Mirror reversal and visual rotation are learned and consolidated via separate mechanisms: recalibrating or learning de novo?

Science.gov (United States)

Telgen, Sebastian; Parvin, Darius; Diedrichsen, Jörn

2014-10-08

Motor learning tasks are often classified into adaptation tasks, which involve the recalibration of an existing control policy (the mapping that determines both feedforward and feedback commands), and skill-learning tasks, requiring the acquisition of new control policies. We show here that this distinction also applies to two different visuomotor transformations during reaching in humans: Mirror-reversal (left-right reversal over a mid-sagittal axis) of visual feedback versus rotation of visual feedback around the movement origin. During mirror-reversal learning, correct movement initiation (feedforward commands) and online corrections (feedback responses) were only generated at longer latencies. The earliest responses were directed into a nonmirrored direction, even after two training sessions. In contrast, for visual rotation learning, no dependency of directional error on reaction time emerged, and fast feedback responses to visual displacements of the cursor were immediately adapted. These results suggest that the motor system acquires a new control policy for mirror reversal, which initially requires extra processing time, while it recalibrates an existing control policy for visual rotations, exploiting established fast computational processes. Importantly, memory for visual rotation decayed between sessions, whereas memory for mirror reversals showed offline gains, leading to better performance at the beginning of the second session than in the end of the first. With shifts in time-accuracy tradeoff and offline gains, mirror-reversal learning shares common features with other skill-learning tasks. We suggest that different neuronal mechanisms underlie the recalibration of an existing versus acquisition of a new control policy and that offline gains between sessions are a characteristic of latter. Copyright © 2014 the authors 0270-6474/14/3413768-12$15.00/0.

Quantitative Susceptibility Mapping: Contrast Mechanisms and Clinical Applications

Science.gov (United States)

Liu, Chunlei; Wei, Hongjiang; Gong, Nan-Jie; Cronin, Matthew; Dibb, Russel; Decker, Kyle

2016-01-01

Quantitative susceptibility mapping (QSM) is a recently developed MRI technique for quantifying the spatial distribution of magnetic susceptibility within biological tissues. It first uses the frequency shift in the MRI signal to map the magnetic field profile within the tissue. The resulting field map is then used to determine the spatial distribution of the underlying magnetic susceptibility by solving an inverse problem. The solution is achieved by deconvolving the field map with a dipole field, under the assumption that the magnetic field is a result of the superposition of the dipole fields generated by all voxels and that each voxel has its unique magnetic susceptibility. QSM provides improved contrast to noise ratio for certain tissues and structures compared to its magnitude counterpart. More importantly, magnetic susceptibility is a direct reflection of the molecular composition and cellular architecture of the tissue. Consequently, by quantifying magnetic susceptibility, QSM is becoming a quantitative imaging approach for characterizing normal and pathological tissue properties. This article reviews the mechanism generating susceptibility contrast within tissues and some associated applications. PMID:26844301

The primary visual cortex in the neural circuit for visual orienting

Science.gov (United States)

Zhaoping, Li

The primary visual cortex (V1) is traditionally viewed as remote from influencing brain's motor outputs. However, V1 provides the most abundant cortical inputs directly to the sensory layers of superior colliculus (SC), a midbrain structure to command visual orienting such as shifting gaze and turning heads. I will show physiological, anatomical, and behavioral data suggesting that V1 transforms visual input into a saliency map to guide a class of visual orienting that is reflexive or involuntary. In particular, V1 receives a retinotopic map of visual features, such as orientation, color, and motion direction of local visual inputs; local interactions between V1 neurons perform a local-to-global computation to arrive at a saliency map that highlights conspicuous visual locations by higher V1 responses. The conspicuous location are usually, but not always, where visual input statistics changes. The population V1 outputs to SC, which is also retinotopic, enables SC to locate, by lateral inhibition between SC neurons, the most salient location as the saccadic target. Experimental tests of this hypothesis will be shown. Variations of the neural circuit for visual orienting across animal species, with more or less V1 involvement, will be discussed. Supported by the Gatsby Charitable Foundation.

High impact data visualization with Power View, Power Map, and Power BI

CERN Document Server

Aspin, Adam

2014-01-01

High Impact Data Visualization with Power View, Power Map, and Power BI helps you take business intelligence delivery to a new level that is interactive, engaging, even fun, all while driving commercial success through sound decision-making. Learn to harness the power of Microsoft's flagship, self-service business intelligence suite to deliver compelling and interactive insight with remarkable ease. Learn the essential techniques needed to enhance the look and feel of reports and dashboards so that you can seize your audience's attention and provide them with clear and accurate information. Al

Visualized Bond Scission in Mechanically Activated Polymers

Institute of Scientific and Technical Information of China (English)

Yuan Yuan; Yu-lan Chen

2017-01-01

Visualization and quantitative evaluation of covalent bond scission in polymeric materials are critical in understanding their failure mechanisms and improving the toughness and reliability of the materials.Mechano-responsive polymers with the ability of molecular-level transduction of force into chromism and luminescence have evoked major interest and experienced significant progress.In the current review,we highlight the recent achievements in covalent mechanochromic and mechanoluminescent polymers,leading to a bridge between macroscopic mechanical properties and microscopic bond scission events.After a general introduction concerning polymer mechanochemistry,various examples that illustrate the strategies of design and incorporation of functional and weak covalent bonds in polymers were presented,the mechanisms underlying the optical phenomenon were introduced and their potential applications as stress sensors were discussed.This review concludes with a comment on the opportunities and challenges of the field.

Airport object extraction based on visual attention mechanism and parallel line detection

Science.gov (United States)

Lv, Jing; Lv, Wen; Zhang, Libao

2017-10-01

Target extraction is one of the important aspects in remote sensing image analysis and processing, which has wide applications in images compression, target tracking, target recognition and change detection. Among different targets, airport has attracted more and more attention due to its significance in military and civilian. In this paper, we propose a novel and reliable airport object extraction model combining visual attention mechanism and parallel line detection algorithm. First, a novel saliency analysis model for remote sensing images with airport region is proposed to complete statistical saliency feature analysis. The proposed model can precisely extract the most salient region and preferably suppress the background interference. Then, the prior geometric knowledge is analyzed and airport runways contained two parallel lines with similar length are detected efficiently. Finally, we use the improved Otsu threshold segmentation method to segment and extract the airport regions from the salient map of remote sensing images. The experimental results demonstrate that the proposed model outperforms existing saliency analysis models and shows good performance in the detection of the airport.

Head orientation of walking blowflies is controlled by visual and mechanical cues

OpenAIRE

Monteagudo Ibarreta, José; Lindemann, Jens Peter; Egelhaaf, Martin

2017-01-01

During locomotion, animals employ visual and mechanical cues in order to establish the orientation of their head, which reflects the orientation of the visual coordinate system. However, in certain situations, contradictory cues may suggest different orientations relative to the environment. We recorded blowflies walking on a horizontal or tilted surface surrounded by visual cues suggesting a variety of orientations.We found that the different orientations relative to gra...

Retinotopic maps and foveal suppression in the visual cortex of amblyopic adults.

Science.gov (United States)

Conner, Ian P; Odom, J Vernon; Schwartz, Terry L; Mendola, Janine D

2007-08-15

Amblyopia is a developmental visual disorder associated with loss of monocular acuity and sensitivity as well as profound alterations in binocular integration. Abnormal connections in visual cortex are known to underlie this loss, but the extent to which these abnormalities are regionally or retinotopically specific has not been fully determined. This functional magnetic resonance imaging (fMRI) study compared the retinotopic maps in visual cortex produced by each individual eye in 19 adults (7 esotropic strabismics, 6 anisometropes and 6 controls). In our standard viewing condition, the non-tested eye viewed a dichoptic homogeneous mid-level grey stimulus, thereby permitting some degree of binocular interaction. Regions-of-interest analysis was performed for extrafoveal V1, extrafoveal V2 and the foveal representation at the occipital pole. In general, the blood oxygenation level-dependent (BOLD) signal was reduced for the amblyopic eye. At the occipital pole, population receptive fields were shifted to represent more parafoveal locations for the amblyopic eye, compared with the fellow eye, in some subjects. Interestingly, occluding the fellow eye caused an expanded foveal representation for the amblyopic eye in one early-onset strabismic subject with binocular suppression, indicating real-time cortical remapping. In addition, a few subjects actually showed increased activity in parietal and temporal cortex when viewing with the amblyopic eye. We conclude that, even in a heterogeneous population, abnormal early visual experience commonly leads to regionally specific cortical adaptations.

A review of visual perception mechanisms that regulate rapid adaptive camouflage in cuttlefish.

Science.gov (United States)

Chiao, Chuan-Chin; Chubb, Charles; Hanlon, Roger T

2015-09-01

We review recent research on the visual mechanisms of rapid adaptive camouflage in cuttlefish. These neurophysiologically complex marine invertebrates can camouflage themselves against almost any background, yet their ability to quickly (0.5-2 s) alter their body patterns on different visual backgrounds poses a vexing challenge: how to pick the correct body pattern amongst their repertoire. The ability of cuttlefish to change appropriately requires a visual system that can rapidly assess complex visual scenes and produce the motor responses-the neurally controlled body patterns-that achieve camouflage. Using specifically designed visual backgrounds and assessing the corresponding body patterns quantitatively, we and others have uncovered several aspects of scene variation that are important in regulating cuttlefish patterning responses. These include spatial scale of background pattern, background intensity, background contrast, object edge properties, object contrast polarity, object depth, and the presence of 3D objects. Moreover, arm postures and skin papillae are also regulated visually for additional aspects of concealment. By integrating these visual cues, cuttlefish are able to rapidly select appropriate body patterns for concealment throughout diverse natural environments. This sensorimotor approach of studying cuttlefish camouflage thus provides unique insights into the mechanisms of visual perception in an invertebrate image-forming eye.

A model of selective visual attention for a stereo pair of images

Science.gov (United States)

Park, Min Chul; Kim, Sung Kyu; Son, Jung-Young

2005-11-01

Human visual attention system has a remarkable ability to interpret complex scenes with the ease and simplicity by selecting or focusing on a small region of visual field without scanning the whole images. In this paper, a novel selective visual attention model by using 3D image display system for a stereo pair of images is proposed. It is based on the feature integration theory and locates ROI(region of interest) or FOA(focus of attention). The disparity map obtained from a stereo pair of images is exploited as one of spatial visual features to form a set of topographic feature maps in our approach. Though the true human cognitive mechanism on the analysis and integration process might be different from our assumption the proposed attention system matches well with the results found by human observers.

High-Resolution Remotely Sensed Small Target Detection by Imitating Fly Visual Perception Mechanism

Directory of Open Access Journals (Sweden)

Fengchen Huang

2012-01-01

Full Text Available The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

High-resolution remotely sensed small target detection by imitating fly visual perception mechanism.

Science.gov (United States)

Huang, Fengchen; Xu, Lizhong; Li, Min; Tang, Min

2012-01-01

The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

Developing a functioning visualization and analysis system for performance assessment

International Nuclear Information System (INIS)

Jones, M.L.

1992-01-01

Various commercial software packages and customized programs provide the ability to analyze and visualize the geology of Yucca Mountain. Starting with sparse, irregularly spaced data a series of gridded models has been developed representing the thermal/mechanical units within the mountain. Using computer aided design (CAD) software and scientific visualization software, the units can be manipulated, analyzed, and graphically displayed. The outputs are typically gridded terrain models, along with files of three-dimensional coordinates, distances, and other dimensional values. Contour maps, profiles, and shaded surfaces are the output for visualization

Persistent visual impairment in multiple sclerosis: prevalence, mechanisms and resulting disability.

Science.gov (United States)

Jasse, Laurence; Vukusic, Sandra; Durand-Dubief, Françoise; Vartin, Cristina; Piras, Carolina; Bernard, Martine; Pélisson, Denis; Confavreux, Christian; Vighetto, Alain; Tilikete, Caroline

2013-10-01

The objective of this article is to evaluate in multiple sclerosis (MS) patients the prevalence of persistent complaints of visual disturbances and the mechanisms and resulting functional disability of persistent visual complaints (PVCs). Firstly, the prevalence of PVCs was calculated in 303 MS patients. MS-related data of patients with or without PVCs were compared. Secondly, 70 patients with PVCs performed an extensive neuro-ophthalmologic assessment and a vision-related quality of life questionnaire, the National Eye Institute Visual Functionary Questionnaire (NEI-VFQ-25). PVCs were reported in 105 MS patients (34.6%). Patients with PVCs had more frequently primary progressive MS (30.5% vs 13.6%) and more neuro-ophthalmologic relapses (1.97 vs 1.36) than patients without PVCs. In the mechanisms/disability study, an afferent visual and an ocular-motor pathways dysfunction were respectively diagnosed in 41 and 59 patients, mostly related to bilateral optic neuropathy and bilateral internuclear ophthalmoplegia. The NEI-VFQ 25 score was poor and significantly correlated with the number of impaired neuro-ophthalmologic tests. Our study emphasizes the high prevalence of PVC in MS patients. Regarding the nature of neuro-ophthalmologic deficit, our results suggest that persistent optic neuropathy, as part of the progressive evolution of the disease, is not rare. We also demonstrate that isolated ocular motor dysfunctions induce visual disability in daily life.

YouGenMap: a web platform for dynamic multi-comparative mapping and visualization of genetic maps

Science.gov (United States)

Keith Batesole; Kokulapalan Wimalanathan; Lin Liu; Fan Zhang; Craig S. Echt; Chun Liang

2014-01-01

Comparative genetic maps are used in examination of genome organization, detection of conserved gene order, and exploration of marker order variations. YouGenMap is an open-source web tool that offers dynamic comparative mapping capability of users' own genetic mapping between 2 or more map sets. Users' genetic map data and optional gene annotations are...

Mapping chromatic pathways in the Drosophila visual system.

Science.gov (United States)

Lin, Tzu-Yang; Luo, Jiangnan; Shinomiya, Kazunori; Ting, Chun-Yuan; Lu, Zhiyuan; Meinertzhagen, Ian A; Lee, Chi-Hon

2016-02-01

In Drosophila, color vision and wavelength-selective behaviors are mediated by the compound eye's narrow-spectrum photoreceptors R7 and R8 and their downstream medulla projection (Tm) neurons Tm5a, Tm5b, Tm5c, and Tm20 in the second optic neuropil or medulla. These chromatic Tm neurons project axons to a deeper optic neuropil, the lobula, which in insects has been implicated in processing and relaying color information to the central brain. The synaptic targets of the chromatic Tm neurons in the lobula are not known, however. Using a modified GFP reconstitution across synaptic partners (GRASP) method to probe connections between the chromatic Tm neurons and 28 known and novel types of lobula neurons, we identify anatomically the visual projection neurons LT11 and LC14 and the lobula intrinsic neurons Li3 and Li4 as synaptic targets of the chromatic Tm neurons. Single-cell GRASP analyses reveal that Li4 receives synaptic contacts from over 90% of all four types of chromatic Tm neurons, whereas LT11 is postsynaptic to the chromatic Tm neurons, with only modest selectivity and at a lower frequency and density. To visualize synaptic contacts at the ultrastructural level, we develop and apply a "two-tag" double-labeling method to label LT11's dendrites and the mitochondria in Tm5c's presynaptic terminals. Serial electron microscopic reconstruction confirms that LT11 receives direct contacts from Tm5c. This method would be generally applicable to map the connections of large complex neurons in Drosophila and other animals. © 2015 Wiley Periodicals, Inc.

Mapping the world: cartographic and geographic visualization by the United Nations Geospatial Information Section (formerly Cartographic Section)

Science.gov (United States)

Kagawa, Ayako; Le Sourd, Guillaume

2018-05-01

United Nations Secretariat activities, mapping began in 1946, and by 1951, the need for maps increased and an office with a team of cartographers was established. Since then, with the development of technologies including internet, remote sensing, unmanned aerial systems, relationship database management and information systems, geospatial information provides an ever-increasing variation of support to the work of the Organization for planning of operations, decision-making and monitoring of crises. However, the need for maps has remained intact. This presentation aims to highlight some of the cartographic representation styles over the decades by reviewing the evolution of selected maps by the office, and noting the changing cognitive and semiotic aspects of cartographic and geographic visualization required by the United Nations. Through presentation and analysis of these maps, the changing dynamics of the Organization in information management can be reflected, with a reminder of the continuing and expanding deconstructionist role of a cartographer, now geospatial information management experts.

Semantic Data And Visualization Techniques Applied To Geologic Field Mapping

Science.gov (United States)

Houser, P. I. Q.; Royo-Leon, M.; Munoz, R.; Estrada, E.; Villanueva-Rosales, N.; Pennington, D. D.

2015-12-01

Geologic field mapping involves the use of technology before, during, and after visiting a site. Geologists utilize hardware such as Global Positioning Systems (GPS) connected to mobile computing platforms such as tablets that include software such as ESRI's ArcPad and other software to produce maps and figures for a final analysis and report. Hand written field notes contain important information and drawings or sketches of specific areas within the field study. Our goal is to collect and geo-tag final and raw field data into a cyber-infrastructure environment with an ontology that allows for large data processing, visualization, sharing, and searching, aiding in connecting field research with prior research in the same area and/or aid with experiment replication. Online searches of a specific field area return results such as weather data from NOAA and QuakeML seismic data from USGS. These results that can then be saved to a field mobile device and searched while in the field where there is no Internet connection. To accomplish this we created the GeoField ontology service using the Web Ontology Language (OWL) and Protégé software. Advanced queries on the dataset can be made using reasoning capabilities can be supported that go beyond a standard database service. These improvements include the automated discovery of data relevant to a specific field site and visualization techniques aimed at enhancing analysis and collaboration while in the field by draping data over mobile views of the site using augmented reality. A case study is being performed at University of Texas at El Paso's Indio Mountains Research Station located near Van Horn, Texas, an active multi-disciplinary field study site. The user can interactively move the camera around the study site and view their data digitally. Geologist's can check their data against the site in real-time and improve collaboration with another person as both parties have the same interactive view of the data.

Driving Pressure Influence in Voltage Maps Measurement Process Using Advanced Pneumatic Mapping Probe

Directory of Open Access Journals (Sweden)

Marek Kukucka

2016-01-01

Full Text Available Our paper deals with the method of the voltage-impedance map measurement process as a method useful for the electric mapping of human skin. The area of research extends from the basic research to its practical application in acupuncture skin mapping and acupuncture point localization and visualization. The problem of sufficient skin coverage and electrical contact with measuring electrodes is solved by the conventional mechanical telescopic electrodes and by the pneumatic matrix electrode probe. A 2D or 3D voltage-impedance map of skin is an output of the measuring, interpretation and evaluation process. New pneumatic construction of measuring probe was implemented to achieve a better coverage of specified skin area and get a reduced force range of the touching electrodes allowing the steady contact of the skin-electrode. A skin contact is related to the driving pressure of touching electrodes. Our paper offers experimentally measured results, voltage maps of skin on specific areas, selected measured and described acupuncture points and their applications in electro-acupuncture.

Mapping shape to visuomotor mapping: learning and generalisation of sensorimotor behaviour based on contextual information.

Directory of Open Access Journals (Sweden)

Loes C J van Dam

2015-03-01

Full Text Available Humans can learn and store multiple visuomotor mappings (dual-adaptation when feedback for each is provided alternately. Moreover, learned context cues associated with each mapping can be used to switch between the stored mappings. However, little is known about the associative learning between cue and required visuomotor mapping, and how learning generalises to novel but similar conditions. To investigate these questions, participants performed a rapid target-pointing task while we manipulated the offset between visual feedback and movement end-points. The visual feedback was presented with horizontal offsets of different amounts, dependent on the targets shape. Participants thus needed to use different visuomotor mappings between target location and required motor response depending on the target shape in order to "hit" it. The target shapes were taken from a continuous set of shapes, morphed between spiky and circular shapes. After training we tested participants performance, without feedback, on different target shapes that had not been learned previously. We compared two hypotheses. First, we hypothesised that participants could (explicitly extract the linear relationship between target shape and visuomotor mapping and generalise accordingly. Second, using previous findings of visuomotor learning, we developed a (implicit Bayesian learning model that predicts generalisation that is more consistent with categorisation (i.e. use one mapping or the other. The experimental results show that, although learning the associations requires explicit awareness of the cues' role, participants apply the mapping corresponding to the trained shape that is most similar to the current one, consistent with the Bayesian learning model. Furthermore, the Bayesian learning model predicts that learning should slow down with increased numbers of training pairs, which was confirmed by the present results. In short, we found a good correspondence between the

Intrathalamic mechanisms of visual attention.

Science.gov (United States)

Mayo, J Patrick

2009-03-01

The classical model of visual processing emphasizes the lateral geniculate nucleus (LGN) as the major intermediary between the retina and visual cortex. Yet, anatomical findings inspired Francis Crick to suggest an alternative model in which the thalamic reticular nucleus, which envelops the LGN, acts as the "guardian" of visual cortex by modulating LGN activity. Recent work by McAlonan and colleagues supports Crick's hypothesis, thereby enhancing our understanding of the early stages of visual processing.

NeatMap--non-clustering heat map alternatives in R.

Science.gov (United States)

Rajaram, Satwik; Oono, Yoshi

2010-01-22

The clustered heat map is the most popular means of visualizing genomic data. It compactly displays a large amount of data in an intuitive format that facilitates the detection of hidden structures and relations in the data. However, it is hampered by its use of cluster analysis which does not always respect the intrinsic relations in the data, often requiring non-standardized reordering of rows/columns to be performed post-clustering. This sometimes leads to uninformative and/or misleading conclusions. Often it is more informative to use dimension-reduction algorithms (such as Principal Component Analysis and Multi-Dimensional Scaling) which respect the topology inherent in the data. Yet, despite their proven utility in the analysis of biological data, they are not as widely used. This is at least partially due to the lack of user-friendly visualization methods with the visceral impact of the heat map. NeatMap is an R package designed to meet this need. NeatMap offers a variety of novel plots (in 2 and 3 dimensions) to be used in conjunction with these dimension-reduction techniques. Like the heat map, but unlike traditional displays of such results, it allows the entire dataset to be displayed while visualizing relations between elements. It also allows superimposition of cluster analysis results for mutual validation. NeatMap is shown to be more informative than the traditional heat map with the help of two well-known microarray datasets. NeatMap thus preserves many of the strengths of the clustered heat map while addressing some of its deficiencies. It is hoped that NeatMap will spur the adoption of non-clustering dimension-reduction algorithms.

ViA: a perceptual visualization assistant

Science.gov (United States)

Healey, Chris G.; St. Amant, Robert; Elhaddad, Mahmoud S.

2000-05-01

This paper describes an automated visualized assistant called ViA. ViA is designed to help users construct perceptually optical visualizations to represent, explore, and analyze large, complex, multidimensional datasets. We have approached this problem by studying what is known about the control of human visual attention. By harnessing the low-level human visual system, we can support our dual goals of rapid and accurate visualization. Perceptual guidelines that we have built using psychophysical experiments form the basis for ViA. ViA uses modified mixed-initiative planning algorithms from artificial intelligence to search of perceptually optical data attribute to visual feature mappings. Our perceptual guidelines are integrated into evaluation engines that provide evaluation weights for a given data-feature mapping, and hints on how that mapping might be improved. ViA begins by asking users a set of simple questions about their dataset and the analysis tasks they want to perform. Answers to these questions are used in combination with the evaluation engines to identify and intelligently pursue promising data-feature mappings. The result is an automatically-generated set of mappings that are perceptually salient, but that also respect the context of the dataset and users' preferences about how they want to visualize their data.

Force scanning: a rapid, high-resolution approach for spatial mechanical property mapping

International Nuclear Information System (INIS)

Darling, E M

2011-01-01

Atomic force microscopy (AFM) can be used to co-localize mechanical properties and topographical features through property mapping techniques. The most common approach for testing biological materials at the microscale and nanoscale is force mapping, which involves taking individual force curves at discrete sites across a region of interest. The limitations of force mapping include long testing times and low resolution. While newer AFM methodologies, like modulated scanning and torsional oscillation, circumvent this problem, their adoption for biological materials has been limited. This could be due to their need for specialized software algorithms and/or hardware. The objective of this study is to develop a novel force scanning technique using AFM to rapidly capture high-resolution topographical images of soft biological materials while simultaneously quantifying their mechanical properties. Force scanning is a straightforward methodology applicable to a wide range of materials and testing environments, requiring no special modification to standard AFMs. Essentially, if a contact-mode image can be acquired, then force scanning can be used to produce a spatial modulus map. The current study first validates this technique using agarose gels, comparing results to ones achieved by the standard force mapping approach. Biologically relevant demonstrations are then presented for high-resolution modulus mapping of individual cells, cell-cell interfaces, and articular cartilage tissue.

Detection of myocardial ischemia by automated, motion-corrected, color-encoded perfusion maps compared with visual analysis of adenosine stress cardiovascular magnetic resonance imaging at 3 T: a pilot study.

Science.gov (United States)

Doesch, Christina; Papavassiliu, Theano; Michaely, Henrik J; Attenberger, Ulrike I; Glielmi, Christopher; Süselbeck, Tim; Fink, Christian; Borggrefe, Martin; Schoenberg, Stefan O

2013-09-01

The purpose of this study was to compare automated, motion-corrected, color-encoded (AMC) perfusion maps with qualitative visual analysis of adenosine stress cardiovascular magnetic resonance imaging for detection of flow-limiting stenoses. Myocardial perfusion measurements applying the standard adenosine stress imaging protocol and a saturation-recovery temporal generalized autocalibrating partially parallel acquisition (t-GRAPPA) turbo fast low angle shot (Turbo FLASH) magnetic resonance imaging sequence were performed in 25 patients using a 3.0-T MAGNETOM Skyra (Siemens Healthcare Sector, Erlangen, Germany). Perfusion studies were analyzed using AMC perfusion maps and qualitative visual analysis. Angiographically detected coronary artery (CA) stenoses greater than 75% or 50% or more with a myocardial perfusion reserve index less than 1.5 were considered as hemodynamically relevant. Diagnostic performance and time requirement for both methods were compared. Interobserver and intraobserver reliability were also assessed. A total of 29 CA stenoses were included in the analysis. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for detection of ischemia on a per-patient basis were comparable using the AMC perfusion maps compared to visual analysis. On a per-CA territory basis, the attribution of an ischemia to the respective vessel was facilitated using the AMC perfusion maps. Interobserver and intraobserver reliability were better for the AMC perfusion maps (concordance correlation coefficient, 0.94 and 0.93, respectively) compared to visual analysis (concordance correlation coefficient, 0.73 and 0.79, respectively). In addition, in comparison to visual analysis, the AMC perfusion maps were able to significantly reduce analysis time from 7.7 (3.1) to 3.2 (1.9) minutes (P < 0.0001). The AMC perfusion maps yielded a diagnostic performance on a per-patient and on a per-CA territory basis comparable with the visual analysis

Independent Attention Mechanisms Control the Activation of Tactile and Visual Working Memory Representations.

Science.gov (United States)

Katus, Tobias; Eimer, Martin

2018-05-01

Working memory (WM) is limited in capacity, but it is controversial whether these capacity limitations are domain-general or are generated independently within separate modality-specific memory systems. These alternative accounts were tested in bimodal visual/tactile WM tasks. In Experiment 1, participants memorized the locations of simultaneously presented task-relevant visual and tactile stimuli. Visual and tactile WM load was manipulated independently (one, two, or three items per modality), and one modality was unpredictably tested after each trial. To track the activation of visual and tactile WM representations during the retention interval, the visual contralateral delay activity (CDA) and tactile CDA (tCDA) were measured over visual and somatosensory cortex, respectively. CDA and tCDA amplitudes were selectively affected by WM load in the corresponding (tactile or visual) modality. The CDA parametrically increased when visual load increased from one to two and to three items. The tCDA was enhanced when tactile load increased from one to two items and showed no further enhancement for three tactile items. Critically, these load effects were strictly modality-specific, as substantiated by Bayesian statistics. Increasing tactile load did not affect the visual CDA, and increasing visual load did not modulate the tCDA. Task performance at memory test was also unaffected by WM load in the other (untested) modality. This was confirmed in a second behavioral experiment where tactile and visual loads were either two or four items, unimodal baseline conditions were included, and participants performed a color change detection task in the visual modality. These results show that WM capacity is not limited by a domain-general mechanism that operates across sensory modalities. They suggest instead that WM storage is mediated by distributed modality-specific control mechanisms that are activated independently and in parallel during multisensory WM.

Explorative analysis of 2D color maps

OpenAIRE

Steiger, Martin; Bernard, Jürgen; Thum, Simon; Mittelstädt, Sebastian; Hutter, Marco; Keim, Daniel A.; Kohlhammer, Jörn

2015-01-01

Color is one of the most important visual variables in information visualization. In many cases, two-dimensional information can be color-coded based on a 2D color map. A variety of color maps as well as a number of quality criteria for the use of color have been presented. The choice of the best color map depends on the analytical task users intend to perform and the design space in choosing an appropriate 2D color map is large. In this paper, we present the ColorMap-Explorer, a visual-inter...

Efficient generation of 3D surfel maps using RGB–D sensors

Directory of Open Access Journals (Sweden)

Wilkowski Artur

2016-03-01

Full Text Available The article focuses on the problem of building dense 3D occupancy maps using commercial RGB-D sensors and the SLAM approach. In particular, it addresses the problem of 3D map representations, which must be able both to store millions of points and to offer efficient update mechanisms. The proposed solution consists of two such key elements, visual odometry and surfel-based mapping, but it contains substantial improvements: storing the surfel maps in octree form and utilizing a frustum culling-based method to accelerate the map update step. The performed experiments verify the usefulness and efficiency of the developed system.

Building Keypoint Mappings on Multispectral Images by a Cascade of Classifiers with a Resurrection Mechanism

Directory of Open Access Journals (Sweden)

Yong Li

2015-05-01

Full Text Available Inspired by the boosting technique for detecting objects, this paper proposes a cascade structure with a resurrection mechanism to establish keypoint mappings on multispectral images. The cascade structure is composed of four steps by utilizing best bin first (BBF, color and intensity distribution of segment (CIDS, global information and the RANSAC process to remove outlier keypoint matchings. Initial keypoint mappings are built with the descriptors associated with keypoints; then, at each step, only a small number of keypoint mappings of a high confidence are classified to be incorrect. The unclassified keypoint mappings will be passed on to subsequent steps for determining whether they are correct. Due to the drawback of a classification rule, some correct keypoint mappings may be misclassified as incorrect at a step. Observing this, we design a resurrection mechanism, so that they will be reconsidered and evaluated by the rules utilized in subsequent steps. Experimental results show that the proposed cascade structure combined with the resurrection mechanism can effectively build more reliable keypoint mappings on multispectral images than existing methods.

Separate visual representations for perception and for visually guided behavior

Science.gov (United States)

Bridgeman, Bruce

1989-01-01

Converging evidence from several sources indicates that two distinct representations of visual space mediate perception and visually guided behavior, respectively. The two maps of visual space follow different rules; spatial values in either one can be biased without affecting the other. Ordinarily the two maps give equivalent responses because both are veridically in register with the world; special techniques are required to pull them apart. One such technique is saccadic suppression: small target displacements during saccadic eye movements are not preceived, though the displacements can change eye movements or pointing to the target. A second way to separate cognitive and motor-oriented maps is with induced motion: a slowly moving frame will make a fixed target appear to drift in the opposite direction, while motor behavior toward the target is unchanged. The same result occurs with stroboscopic induced motion, where the frame jump abruptly and the target seems to jump in the opposite direction. A third method of separating cognitive and motor maps, requiring no motion of target, background or eye, is the Roelofs effect: a target surrounded by an off-center rectangular frame will appear to be off-center in the direction opposite the frame. Again the effect influences perception, but in half of the subjects it does not influence pointing to the target. This experience also reveals more characteristics of the maps and their interactions with one another, the motor map apparently has little or no memory, and must be fed from the biased cognitive map if an enforced delay occurs between stimulus presentation and motor response. In designing spatial displays, the results mean that what you see isn't necessarily what you get. Displays must be designed with either perception or visually guided behavior in mind.

Integrating mechanisms of visual guidance in naturalistic language production.

Science.gov (United States)

Coco, Moreno I; Keller, Frank

2015-05-01

Situated language production requires the integration of visual attention and linguistic processing. Previous work has not conclusively disentangled the role of perceptual scene information and structural sentence information in guiding visual attention. In this paper, we present an eye-tracking study that demonstrates that three types of guidance, perceptual, conceptual, and structural, interact to control visual attention. In a cued language production experiment, we manipulate perceptual (scene clutter) and conceptual guidance (cue animacy) and measure structural guidance (syntactic complexity of the utterance). Analysis of the time course of language production, before and during speech, reveals that all three forms of guidance affect the complexity of visual responses, quantified in terms of the entropy of attentional landscapes and the turbulence of scan patterns, especially during speech. We find that perceptual and conceptual guidance mediate the distribution of attention in the scene, whereas structural guidance closely relates to scan pattern complexity. Furthermore, the eye-voice span of the cued object and its perceptual competitor are similar; its latency mediated by both perceptual and structural guidance. These results rule out a strict interpretation of structural guidance as the single dominant form of visual guidance in situated language production. Rather, the phase of the task and the associated demands of cross-modal cognitive processing determine the mechanisms that guide attention.

Exploring the Impact of Visual Complexity Levels in 3d City Models on the Accuracy of Individuals' Orientation and Cognitive Maps

Science.gov (United States)

Rautenbach, V.; Çöltekin, A.; Coetzee, S.

2015-08-01

In this paper we report results from a qualitative user experiment (n=107) designed to contribute to understanding the impact of various levels of complexity (mainly based on levels of detail, i.e., LoD) in 3D city models, specifically on the participants' orientation and cognitive (mental) maps. The experiment consisted of a number of tasks motivated by spatial cognition theory where participants (among other things) were given orientation tasks, and in one case also produced sketches of a path they `travelled' in a virtual environment. The experiments were conducted in groups, where individuals provided responses on an answer sheet. The preliminary results based on descriptive statistics and qualitative sketch analyses suggest that very little information (i.e., a low LoD model of a smaller area) might have a negative impact on the accuracy of cognitive maps constructed based on a virtual experience. Building an accurate cognitive map is an inherently desired effect of the visualizations in planning tasks, thus the findings are important for understanding how to develop better-suited 3D visualizations such as 3D city models. In this study, we specifically discuss the suitability of different levels of visual complexity for development planning (urban planning), one of the domains where 3D city models are most relevant.

Visual assessment of BIPV retrofit design proposals for selected historical buildings using the saliency map method

Directory of Open Access Journals (Sweden)

Ran Xu

2015-06-01

Full Text Available With the increasing awareness of energy efficiency, many old buildings have to undergo a massive facade energy retrofit. How to predict the visual impact which solar installations on the aesthetic cultural value of these buildings has been a heated debate in Switzerland (and throughout the world. The usual evaluation method to describe the visual impact of BIPV is based on semantic and qualitative descriptors, and strongly dependent on personal preferences. The evaluation scale is therefore relative, flexible and imprecise. This paper proposes a new method to accurately measure the visual impact which BIPV installations have on a historical building by using the saliency map method. By imitating working principles of the human eye, it is measured how much the BIPV design proposals differ from the original building facade in the aspect of attracting human visual attention. The result is directly presented in a quantitative manner, and can be used to compare the fitness of different BIPV design proposals. The measuring process is numeric, objective and more precise.  

Mapping the Words: Experimental visualizations of translation structures between Ancient Greek and Classical Arabic

Directory of Open Access Journals (Sweden)

Torsten Roeder

2017-11-01

Full Text Available The article deals with presentation forms of linguistic transformation processes from ancient Greek sources that were translated into classical Arabic from the 9th to 11th century AD. Various examples demonstrate how visualizations support the interpretation of corpus structures, lexical differentiation, grammatical transformation and translation processes for single lexemes in the database project Glossarium Graeco-Arabicum. The database contains about 100,000 manually collected word pairs (still growing from 76 texts and their translations. The article discusses how the project utilizes Sankey diagrams, tree maps, balloon charts, data grids and classical coordinate systems to point out specific aspects of the data. Visualizations not only help beginners to understand the corpus structure, they also help editors and specialized users to identify specific phenomena. A well-documented interface design is crucial both for usability and interpretative work.

Developmental changes in GABAergic mechanisms in human visual cortex across the lifespan

Directory of Open Access Journals (Sweden)

Joshua G A Pinto

2010-06-01

Full Text Available Functional maturation of visual cortex is linked with dynamic changes in synaptic expression of GABAergic mechanisms. These include setting the excitation-inhibition balance required for experience-dependent plasticity, as well as, intracortical inhibition underlying development and aging of receptive field properties. Animal studies have shown developmental regulation of GABAergic mechanisms in visual cortex. In this study, we show for the first time how these mechanisms develop in the human visual cortex across the lifespan. We used Western blot analysis of postmortem tissue from human primary visual cortex (n=30, range: 20 days to 80 years to quantify expression of 8 pre- and post-synaptic GABAergic markers. We quantified the inhibitory modulating cannabinoid receptor (CB1, GABA vesicular transporter (VGAT, GABA synthesizing enzymes (GAD65/GAD67, GABAA receptor anchoring protein (Gephyrin, and GABAA receptor subunits (GABAA∝1, GABAA∝2, GABAA∝3. We found a complex pattern of changes, many of which were prolonged and continued well into into the teen, young adult, and even older adult years. These included a monotonic increase or decrease (GABAA∝1, GABAA∝2, a biphasic increase then decrease (GAD65, Gephyrin, or multiple increases and decreases (VGAT, CB1 across the lifespan. Comparing the balances between the pre- and post-synaptic markers we found 3 main transitions (early childhood, early teen years, aging when there were rapid switches in the composition of the GABAergic signaling system, indicating that functioning of the GABAergic system must change as the visual cortex develops and ages. Furthermore, these results provide key information for translating therapies developed in animal models into effective treatments for amblyopia in humans.

Interactions between visual working memory and visual attention

NARCIS (Netherlands)

Olivers, C.N.L.

2008-01-01

Visual attention is the collection of mechanisms by which relevant visual information is selected, and irrelevant visual information is ignored. Visual working memory is the mechanism by which relevant visual information is retained, and irrelevant information is suppressed. In addition to this

Circuit Mechanisms Governing Local vs. Global Motion Processing in Mouse Visual Cortex

DEFF Research Database (Denmark)

Rasmussen, Rune; Yonehara, Keisuke

2017-01-01

components represented by component direction-selective (CDS) cells. However, how PDS and CDS cells develop their distinct response properties is still unresolved. The visual cortex of the mouse is an attractive model for experimentally solving this issue due to the large molecular and genetic toolbox...... literature on global motion processing based on works in primates and mice. Lastly, we propose what types of experiments could illuminate what circuit mechanisms are governing cortical global visual motion processing. We propose that PDS cells in mouse visual cortex appear as the perfect arena...

Can Probability Maps of Swept-Source Optical Coherence Tomography Predict Visual Field Changes in Preperimetric Glaucoma?

Science.gov (United States)

Lee, Won June; Kim, Young Kook; Jeoung, Jin Wook; Park, Ki Ho

2017-12-01

To determine the usefulness of swept-source optical coherence tomography (SS-OCT) probability maps in detecting locations with significant reduction in visual field (VF) sensitivity or predicting future VF changes, in patients with classically defined preperimetric glaucoma (PPG). Of 43 PPG patients, 43 eyes were followed-up on every 6 months for at least 2 years were analyzed in this longitudinal study. The patients underwent wide-field SS-OCT scanning and standard automated perimetry (SAP) at the time of enrollment. With this wide-scan protocol, probability maps originating from the corresponding thickness map and overlapped with SAP VF test points could be generated. We evaluated the vulnerable VF points with SS-OCT probability maps as well as the prevalence of locations with significant VF reduction or subsequent VF changes observed in the corresponding damaged areas of the probability maps. The vulnerable VF points were shown in superior and inferior arcuate patterns near the central fixation. In 19 of 43 PPG eyes (44.2%), significant reduction in baseline VF was detected within the areas of structural change on the SS-OCT probability maps. In 16 of 43 PPG eyes (37.2%), subsequent VF changes within the areas of SS-OCT probability map change were observed over the course of the follow-up. Structural changes on SS-OCT probability maps could detect or predict VF changes using SAP, in a considerable number of PPG eyes. Careful comparison of probability maps with SAP results could be useful in diagnosing and monitoring PPG patients in the clinical setting.

Use of Concept Maps as an Assessment Tool in Mechanical Engineering Education

Science.gov (United States)

Tembe, B. L.; Kamble, S. K.

2013-01-01

The purpose of this study to investigate, how third year mechanical engineering students are able to use their knowledge of concept maps in their study of the topic of "Introduction to the Internal Combustion Engines (IICE)". 41 students participated in this study. Firstly, the students were taught about concept maps and then asked to…

TheCellMap.org: A Web-Accessible Database for Visualizing and Mining the Global Yeast Genetic Interaction Network.

Science.gov (United States)

Usaj, Matej; Tan, Yizhao; Wang, Wen; VanderSluis, Benjamin; Zou, Albert; Myers, Chad L; Costanzo, Michael; Andrews, Brenda; Boone, Charles

2017-05-05

Providing access to quantitative genomic data is key to ensure large-scale data validation and promote new discoveries. TheCellMap.org serves as a central repository for storing and analyzing quantitative genetic interaction data produced by genome-scale Synthetic Genetic Array (SGA) experiments with the budding yeast Saccharomyces cerevisiae In particular, TheCellMap.org allows users to easily access, visualize, explore, and functionally annotate genetic interactions, or to extract and reorganize subnetworks, using data-driven network layouts in an intuitive and interactive manner. Copyright © 2017 Usaj et al.

GLAM: Glycogen-derived Lactate Absorption Map for visual analysis of dense and sparse surface reconstructions of rodent brain structures on desktop systems and virtual environments

KAUST Repository

Agus, Marco; Boges, Daniya; Gagnon, Nicolas; Magistretti, Pierre J.; Hadwiger, Markus; Cali, Corrado

2018-01-01

Human brain accounts for about one hundred billion neurons, but they cannot work properly without ultrastructural and metabolic support. For this reason, mammalian brains host another type of cells called “glial cells”, whose role is to maintain proper conditions for efficient neuronal function. One type of glial cell, astrocytes, are involved in particular in the metabolic support of neurons, by feeding them with lactate, one byproduct of glucose metabolism that they can take up from blood vessels, and store it under another form, glycogen granules. These energy-storage molecules, whose morphology resembles to spheres with a diameter ranging 10–80 nanometers roughly, can be easily recognized using electron microscopy, the only technique whose resolution is high enough to resolve them. Understanding and quantifying their distribution is of particular relevance for neuroscientists, in order to understand where and when neurons use energy under this form. To answer this question, we developed a visualization technique, dubbed GLAM (Glycogen-derived Lactate Absorption Map), and customized for the analysis of the interaction of astrocytic glycogen on surrounding neurites in order to formulate hypotheses on the energy absorption mechanisms. The method integrates high-resolution surface reconstruction of neurites, astrocytes, and the energy sources in form of glycogen granules from different automated serial electron microscopy methods, like focused ion beam scanning electron microscopy (FIB-SEM) or serial block face electron microscopy (SBEM), together with an absorption map computed as a radiance transfer mechanism. The resulting visual representation provides an immediate and comprehensible illustration of the areas in which the probability of lactate shuttling is higher. The computed dataset can be then explored and quantified in a 3D space, either using 3D modeling software or virtual reality environments. Domain scientists have evaluated the technique by

GLAM: Glycogen-derived Lactate Absorption Map for visual analysis of dense and sparse surface reconstructions of rodent brain structures on desktop systems and virtual environments

KAUST Repository

Agus, Marco

2018-05-21

Human brain accounts for about one hundred billion neurons, but they cannot work properly without ultrastructural and metabolic support. For this reason, mammalian brains host another type of cells called “glial cells”, whose role is to maintain proper conditions for efficient neuronal function. One type of glial cell, astrocytes, are involved in particular in the metabolic support of neurons, by feeding them with lactate, one byproduct of glucose metabolism that they can take up from blood vessels, and store it under another form, glycogen granules. These energy-storage molecules, whose morphology resembles to spheres with a diameter ranging 10–80 nanometers roughly, can be easily recognized using electron microscopy, the only technique whose resolution is high enough to resolve them. Understanding and quantifying their distribution is of particular relevance for neuroscientists, in order to understand where and when neurons use energy under this form. To answer this question, we developed a visualization technique, dubbed GLAM (Glycogen-derived Lactate Absorption Map), and customized for the analysis of the interaction of astrocytic glycogen on surrounding neurites in order to formulate hypotheses on the energy absorption mechanisms. The method integrates high-resolution surface reconstruction of neurites, astrocytes, and the energy sources in form of glycogen granules from different automated serial electron microscopy methods, like focused ion beam scanning electron microscopy (FIB-SEM) or serial block face electron microscopy (SBEM), together with an absorption map computed as a radiance transfer mechanism. The resulting visual representation provides an immediate and comprehensible illustration of the areas in which the probability of lactate shuttling is higher. The computed dataset can be then explored and quantified in a 3D space, either using 3D modeling software or virtual reality environments. Domain scientists have evaluated the technique by

Design, Qualification and Lessons Learned of the Shutter Calibration Mechanism for EnMAP Mission

Science.gov (United States)

Schmidt, Tilo; Muller, Silvio; Bergander, Arvid; Zajac, Kai; Seifart, Klaus

2015-09-01

The Shutter Calibration Mechanism (SCM) Assembly is one of three mechanisms which are developed by HTS for the EnMAP instrument in subcontract to OHB System AG Munich. EnMAP is the Environmental Mapping and Analysis Program of the German Space Agency DLR.The binary rotary encoder of the SCM using hall-effect sensors was already presented during ESMATS 2011. This paper summarizes the main functions and design features of the Hardware and focuses on qualification testing which has finished successfully in 2014. Of particular interest is the functional testing of the main drive including the precise hall-effect position sensing system and the test of the fail safe mechanism. In addition to standard test campaign required for QM also a shock emission measurement of the fail safe mechanism activation was conducted.Test conduction and results will be presented with focus on deviations from the expected behaviour, mitigation measures and on lessons learned.

EVALUATION OF THE USER STRATEGY ON 2D AND 3D CITY MAPS BASED ON NOVEL SCANPATH COMPARISON METHOD AND GRAPH VISUALIZATION

Directory of Open Access Journals (Sweden)

J. Dolezalova

2016-06-01

Full Text Available The paper is dealing with scanpath comparison of eye-tracking data recorded during case study focused on the evaluation of 2D and 3D city maps. The experiment contained screenshots from three map portals. Two types of maps were used - standard map and 3D visualization. Respondents’ task was to find particular point symbol on the map as fast as possible. Scanpath comparison is one group of the eye-tracking data analyses methods used for revealing the strategy of the respondents. In cartographic studies, the most commonly used application for scanpath comparison is eyePatterns that output is hierarchical clustering and a tree graph representing the relationships between analysed sequences. During an analysis of the algorithm generating a tree graph, it was found that the outputs do not correspond to the reality. We proceeded to the creation of a new tool called ScanGraph. This tool uses visualization of cliques in simple graphs and is freely available at www.eyetracking.upol.cz/scangraph. Results of the study proved the functionality of the tool and its suitability for analyses of different strategies of map readers. Based on the results of the tool, similar scanpaths were selected, and groups of respondents with similar strategies were identified. With this knowledge, it is possible to analyse the relationship between belonging to the group with similar strategy and data gathered from the questionnaire (age, sex, cartographic knowledge, etc. or type of stimuli (2D, 3D map.

Evaluation of the User Strategy on 2d and 3d City Maps Based on Novel Scanpath Comparison Method and Graph Visualization

Science.gov (United States)

Dolezalova, J.; Popelka, S.

2016-06-01

The paper is dealing with scanpath comparison of eye-tracking data recorded during case study focused on the evaluation of 2D and 3D city maps. The experiment contained screenshots from three map portals. Two types of maps were used - standard map and 3D visualization. Respondents' task was to find particular point symbol on the map as fast as possible. Scanpath comparison is one group of the eye-tracking data analyses methods used for revealing the strategy of the respondents. In cartographic studies, the most commonly used application for scanpath comparison is eyePatterns that output is hierarchical clustering and a tree graph representing the relationships between analysed sequences. During an analysis of the algorithm generating a tree graph, it was found that the outputs do not correspond to the reality. We proceeded to the creation of a new tool called ScanGraph. This tool uses visualization of cliques in simple graphs and is freely available at www.eyetracking.upol.cz/scangraph. Results of the study proved the functionality of the tool and its suitability for analyses of different strategies of map readers. Based on the results of the tool, similar scanpaths were selected, and groups of respondents with similar strategies were identified. With this knowledge, it is possible to analyse the relationship between belonging to the group with similar strategy and data gathered from the questionnaire (age, sex, cartographic knowledge, etc.) or type of stimuli (2D, 3D map).

Simulating and visualizing deflections of a remote handling mechanism

International Nuclear Information System (INIS)

Saarinen, Hannu; Hämäläinen, Vesa; Karjalainen, Jaakko; Määttä, Timo; Siuko, Mikko; Esqué, Salvador; Hamilton, David

2013-01-01

Highlights: ► An infinitesimal transformation represents elastic deflections. ► Equivalent spring factor is used to combine several deformations. ► Initial VR model accuracy improved from 80 to 5 mm. ► The deflection model is capable of adapting to changes in load at the end-effector. ► The algorithms and approach described are generic and can be adopted for other mechanisms. -- Abstract: Continuing ITER divertor second cassette (SC) remote handling (RH) test campaign has been carried out at divertor test platform (DTP2) in Finland. One of the goals has been to develop and implement efficient algorithms and software tools for simulating and visualizing for the operator the non-instrumented deflections of the RH mechanisms under loading conditions. Based on assumptions of the classical beam theory, the presented solution suggests utilization of an infinitesimal transformation to represent elastic deflections in a mechanical structure. Both structural analysis and measurements of the real structure are utilised during the process. The solution suggests one possible implementation strategy of a software component called structural simulator (SS), which is a software component of the remote handling control system (RHCS) architectural model specified by ITER organisation. Utilisation of the proposed SS necessitates modification of the initial virtual reality (VR) model of RH equipment to a format, which can visually represent the structural deflections. In practise this means adding virtual joints into the model. This will improve the accuracy of the VR visualization and will ensure that the virtual representation of the RH equipment closely aligns with the actual RH equipment. Cassette multifunctional mover (CMM) and second cassette end effector (SCEE) carrying SC were selected to be the initial target system for developing the approach. Demonstrations proved that the approach used can give high levels of accuracy even in complex structures such as the CMM

Simulating and visualizing deflections of a remote handling mechanism

Energy Technology Data Exchange (ETDEWEB)

Saarinen, Hannu, E-mail: hannu.saarinen@vtt.fi [VTT, Technical Research Centre of Finland, Tekniikankatu 1, 33720 Tampere (Finland); Hämäläinen, Vesa; Karjalainen, Jaakko; Määttä, Timo; Siuko, Mikko [VTT, Technical Research Centre of Finland, Tekniikankatu 1, 33720 Tampere (Finland); Esqué, Salvador [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Hamilton, David [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

2013-10-15

Highlights: ► An infinitesimal transformation represents elastic deflections. ► Equivalent spring factor is used to combine several deformations. ► Initial VR model accuracy improved from 80 to 5 mm. ► The deflection model is capable of adapting to changes in load at the end-effector. ► The algorithms and approach described are generic and can be adopted for other mechanisms. -- Abstract: Continuing ITER divertor second cassette (SC) remote handling (RH) test campaign has been carried out at divertor test platform (DTP2) in Finland. One of the goals has been to develop and implement efficient algorithms and software tools for simulating and visualizing for the operator the non-instrumented deflections of the RH mechanisms under loading conditions. Based on assumptions of the classical beam theory, the presented solution suggests utilization of an infinitesimal transformation to represent elastic deflections in a mechanical structure. Both structural analysis and measurements of the real structure are utilised during the process. The solution suggests one possible implementation strategy of a software component called structural simulator (SS), which is a software component of the remote handling control system (RHCS) architectural model specified by ITER organisation. Utilisation of the proposed SS necessitates modification of the initial virtual reality (VR) model of RH equipment to a format, which can visually represent the structural deflections. In practise this means adding virtual joints into the model. This will improve the accuracy of the VR visualization and will ensure that the virtual representation of the RH equipment closely aligns with the actual RH equipment. Cassette multifunctional mover (CMM) and second cassette end effector (SCEE) carrying SC were selected to be the initial target system for developing the approach. Demonstrations proved that the approach used can give high levels of accuracy even in complex structures such as the CMM

Intrathalamic Mechanisms of Visual Attention

OpenAIRE

Mayo, J. Patrick

2009-01-01

The classical model of visual processing emphasizes the lateral geniculate nucleus (LGN) as the major intermediary between the retina and visual cortex. Yet, anatomical findings inspired Francis Crick to suggest an alternative model in which the thalamic reticular nucleus, which envelops the LGN, acts as the “guardian” of visual cortex by modulating LGN activity. Recent work by McAlonan and colleagues supports Crick's hypothesis, thereby enhancing our understanding of the early stages of visu...

Modeling, analysis, and visualization of anisotropy

CERN Document Server

Özarslan, Evren; Hotz, Ingrid

2017-01-01

This book focuses on the modeling, processing and visualization of anisotropy, irrespective of the context in which it emerges, using state-of-the-art mathematical tools. As such, it differs substantially from conventional reference works, which are centered on a particular application. It covers the following topics: (i) the geometric structure of tensors, (ii) statistical methods for tensor field processing, (iii) challenges in mapping neural connectivity and structural mechanics, (iv) processing of uncertainty, and (v) visualizing higher-order representations. In addition to original research contributions, it provides insightful reviews. This multidisciplinary book is the sixth in a series that aims to foster scientific exchange between communities employing tensors and other higher-order representations of directionally dependent data. A significant number of the chapters were co-authored by the participants of the workshop titled Multidisciplinary Approaches to Multivalued Data: Modeling, Visualization,...

Glocalized New Age Spirituality: A Mental Map of the New Central Bus Station in Tel Aviv, Deciphered through Its Visual Codes and Based on Ethno-Visual Research

Science.gov (United States)

Ben-Peshat, Malka; Sitton, Shoshana

2011-01-01

We present here the findings of an ethno-visual research study involving the creation of a mental map of images, artifacts and practices in Tel Aviv's New Central Bus Station. This huge and complex building, part bus station, part shopping mall, has become a stage for multicultural encounters and interactions among diverse communities of users.…

Clinical evaluation of coronary territory map by using unfolded map of Tl-201 myocardial SPECT

International Nuclear Information System (INIS)

Uehara, Toshiisa; Nishimura, Tsunehiko; Katafuchi, Tetsuro; Yamagami, Hidetoshi; Kumita, Shinichirou; Hayashida, Kohei; Hayashi, Makoto

1990-01-01

Coronary territory map was developed on unfolded map of exercise Tl-201 myocardial SPECT. Each coronary territory was determined by summing the each unfolded map of 54 cases of single vessel disease respectively, and standardizing with normal pattern obtained from normal patients. The diagnostic accuracy of coronary territory map to identify the diseased coronary artery was analyzed in 104 clinical cases and was compared with that of planar and SPECT visual diagnosis, simple unfolded map (raw map) and extent and severity map. The results were as follows. (1) Territory map showed excellent diagnostic accuracy in single or double vessel disease, especially in diagnosis of left circumflex coronary artery lesion. (2) In triple vessel disease, the diagnostic accuracy of territory map or other unfolded maps was 30% at best, and was inferior to planar or SPECT visual analysis. The cause of this inferiority seemed that the quantitatively analyzed map had no information about the degree of Tl-uptake into lung or myocardium, which give useful information in visual diagnosis. (3) The diagnostic agreement ratio in two observers was the highest in territory map diagnosis, so that the territory map diagnosis seemed to be the most objective one. (4) The unfolded map diagnosis with apical display obtained from long-axis tomogram was useful to diagnose left anteior descending coronary (LAD) lesion, which improve not only the sensitivity of LAD but also specificity of right coronary artery single vessel disease. (author)

Learning Building Layouts with Non-geometric Visual Information: The Effects of Visual Impairment and Age

Science.gov (United States)

Kalia, Amy A.; Legge, Gordon E.; Giudice, Nicholas A.

2009-01-01

Previous studies suggest that humans rely on geometric visual information (hallway structure) rather than non-geometric visual information (e.g., doors, signs and lighting) for acquiring cognitive maps of novel indoor layouts. This study asked whether visual impairment and age affect reliance on non-geometric visual information for layout learning. We tested three groups of participants—younger (sighted, older (50–70 years) normally sighted, and low vision (people with heterogeneous forms of visual impairment ranging in age from 18–67). Participants learned target locations in building layouts using four presentation modes: a desktop virtual environment (VE) displaying only geometric cues (Sparse VE), a VE displaying both geometric and non-geometric cues (Photorealistic VE), a Map, and a Real building. Layout knowledge was assessed by map drawing and by asking participants to walk to specified targets in the real space. Results indicate that low-vision and older normally-sighted participants relied on additional non-geometric information to accurately learn layouts. In conclusion, visual impairment and age may result in reduced perceptual and/or memory processing that makes it difficult to learn layouts without non-geometric visual information. PMID:19189732

Arctic Research Mapping Application (ARMAP): visualize project-level information for U.S. funded research in the Arctic

Science.gov (United States)

Kassin, A.; Cody, R. P.; Barba, M.; Escarzaga, S. M.; Score, R.; Dover, M.; Gaylord, A. G.; Manley, W. F.; Habermann, T.; Tweedie, C. E.

2015-12-01

The Arctic Research Mapping Application (ARMAP; http://armap.org/) is a suite of online applications and data services that support Arctic science by providing project tracking information (who's doing what, when and where in the region) for United States Government funded projects. In collaboration with 17 research agencies, project locations are displayed in a visually enhanced web mapping application. Key information about each project is presented along with links to web pages that provide additional information. The mapping application includes new reference data layers and an updated ship tracks layer. Visual enhancements are achieved by redeveloping the front-end from FLEX to HTML5 and JavaScript, which now provide access to mobile users utilizing tablets and cell phone devices. New tools have been added that allow users to navigate, select, draw, measure, print, use a time slider, and more. Other module additions include a back-end Apache SOLR search platform that provides users with the capability to perform advance searches throughout the ARMAP database. Furthermore, a new query builder interface has been developed in order to provide more intuitive controls to generate complex queries. These improvements have been made to increase awareness of projects funded by numerous entities in the Arctic, enhance coordination for logistics support, help identify geographic gaps in research efforts and potentially foster more collaboration amongst researchers working in the region. Additionally, ARMAP can be used to demonstrate past, present, and future research efforts supported by the U.S. Government.

Interactive density maps for moving objects

NARCIS (Netherlands)

Scheepens, R.J.; Willems, C.M.E.; Wetering, van de H.M.M.; Wijk, van J.J.

2012-01-01

Trajectories capture the movements of objects with multiple attributes. A visualization method called density maps shows trends in these trajectories. Density map creation involves aggregating smoothed trajectories in a density field and then visualizing the field. Users can explore attributes along

Cortico-Cortical Receptive Field Estimates in Human Visual Cortex

Directory of Open Access Journals (Sweden)

Koen V Haak

2012-05-01

Full Text Available Human visual cortex comprises many visual areas that contain a map of the visual field (Wandell et al 2007, Neuron 56, 366–383. These visual field maps can be identified readily in individual subjects with functional magnetic resonance imaging (fMRI during experimental sessions that last less than an hour (Wandell and Winawer 2011, Vis Res 718–737. Hence, visual field mapping with fMRI has been, and still is, a heavily used technique to examine the organisation of both normal and abnormal human visual cortex (Haak et al 2011, ACNR, 11(3, 20–21. However, visual field mapping cannot reveal every aspect of human visual cortex organisation. For example, the information processed within a visual field map arrives from somewhere and is sent to somewhere, and visual field mapping does not derive these input/output relationships. Here, we describe a new, model-based analysis for estimating the dependence between signals in distinct cortical regions using functional magnetic resonance imaging (fMRI data. Just as a stimulus-referred receptive field predicts the neural response as a function of the stimulus contrast, the neural-referred receptive field predicts the neural response as a function of responses elsewhere in the nervous system. When applied to two cortical regions, this function can be called the cortico-cortical receptive field (CCRF. We model the CCRF as a Gaussian-weighted region on the cortical surface and apply the model to data from both stimulus-driven and resting-state experimental conditions in visual cortex.

Proportional Symbol Mapping in R

Directory of Open Access Journals (Sweden)

Susumu Tanimura

2006-01-01

Full Text Available Visualization of spatial data on a map aids not only in data exploration but also in communication to impart spatial conception or ideas to others. Although recent carto-graphic functions in R are rapidly becoming richer, proportional symbol mapping, which is one of the common mapping approaches, has not been packaged thus far. Based on the theories of proportional symbol mapping developed in cartography, the authors developed some functions for proportional symbol mapping using R, including mathematical and perceptual scaling. An example of these functions demonstrated the new expressive power and options available in R, particularly for the visualization of conceptual point data.

The structure of pairwise correlation in mouse primary visual cortex reveals functional organization in the absence of an orientation map.

Science.gov (United States)

Denman, Daniel J; Contreras, Diego

2014-10-01

Neural responses to sensory stimuli are not independent. Pairwise correlation can reduce coding efficiency, occur independent of stimulus representation, or serve as an additional channel of information, depending on the timescale of correlation and the method of decoding. Any role for correlation depends on its magnitude and structure. In sensory areas with maps, like the orientation map in primary visual cortex (V1), correlation is strongly related to the underlying functional architecture, but it is unclear whether this correlation structure is an essential feature of the system or arises from the arrangement of cells in the map. We assessed the relationship between functional architecture and pairwise correlation by measuring both synchrony and correlated spike count variability in mouse V1, which lacks an orientation map. We observed significant pairwise synchrony, which was organized by distance and relative orientation preference between cells. We also observed nonzero correlated variability in both the anesthetized (0.16) and awake states (0.18). Our results indicate that the structure of pairwise correlation is maintained in the absence of an underlying anatomical organization and may be an organizing principle of the mammalian visual system preserved by nonrandom connectivity within local networks. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Visualization maps for the evolution of research hotspots in the field of regional health information networks.

Science.gov (United States)

Wang, Yanjun; Zheng, Jianzhong; Zhang, Ailian; Zhou, Wei; Dong, Haiyuan

2018-03-01

The aim of this study was to reveal research hotspots in the field of regional health information networks (RHINs) and use visualization techniques to explore their evolution over time and differences between countries. We conducted a literature review for a 50-year period and compared the prevalence of certain index terms during the periods 1963-1993 and 1994-2014 and in six countries. We applied keyword frequency analysis, keyword co-occurrence analysis, multidimensional scaling analysis, and network visualization technology. The total number of keywords was found to increase with time. From 1994 to 2014, the research priorities shifted from hospital planning to community health planning. The number of keywords reflecting information-based research increased. The density of the knowledge network increased significantly, and partial keywords condensed into knowledge groups. All six countries focus on keywords including Information Systems; Telemedicine; Information Service; Medical Records Systems, Computerized; Internet; etc.; however, the level of development and some research priorities are different. RHIN research has generally increased in popularity over the past 50 years. The research hotspots are evolving and are at different levels of development in different countries. Knowledge network mapping and perceptual maps provide useful information for scholars, managers, and policy-makers.

From retinal waves to activity-dependent retinogeniculate map development.

Science.gov (United States)

Markowitz, Jeffrey; Cao, Yongqiang; Grossberg, Stephen

2012-01-01

A neural model is described of how spontaneous retinal waves are formed in infant mammals, and how these waves organize activity-dependent development of a topographic map in the lateral geniculate nucleus, with connections from each eye segregated into separate anatomical layers. The model simulates the spontaneous behavior of starburst amacrine cells and retinal ganglion cells during the production of retinal waves during the first few weeks of mammalian postnatal development. It proposes how excitatory and inhibitory mechanisms within individual cells, such as Ca(2+)-activated K(+) channels, and cAMP currents and signaling cascades, can modulate the spatiotemporal dynamics of waves, notably by controlling the after-hyperpolarization currents of starburst amacrine cells. Given the critical role of the geniculate map in the development of visual cortex, these results provide a foundation for analyzing the temporal dynamics whereby the visual cortex itself develops.

Visualizing Mobility of Public Transportation System.

Science.gov (United States)

Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

2014-12-01

Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

Neural mechanisms underlying sound-induced visual motion perception: An fMRI study.

Science.gov (United States)

Hidaka, Souta; Higuchi, Satomi; Teramoto, Wataru; Sugita, Yoichi

2017-07-01

Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM. Copyright © 2017 Elsevier B.V. All rights reserved.

Visual data mining with self-organising maps for ventricular fibrillation analysis.

Science.gov (United States)

Rosado-Muñoz, Alfredo; Martínez-Martínez, José M; Escandell-Montero, Pablo; Soria-Olivas, Emilio

2013-08-01

Detection of ventricular fibrillation (VF) at an early stage is being deeply studied in order to lower the risk of sudden death and allows the specialist to have greater reaction time to give the patient a good recovering therapy. Some works are focusing on detecting VF based on numerical analysis of time-frequency distributions, but in general the methods used do not provide insight into the problem. However, this study proposes a new methodology in order to obtain information about this problem. This work uses a supervised self-organising map (SOM) to obtain visually information among four important groups of patients: VF (ventricular fibrillation), VT (ventricular tachycardia), HP (healthy patients) and AHR (other anomalous heart rates and noise). A total number of 27 variables were obtained from continuous surface ECG recordings in standard databases (MIT and AHA), providing information in the time, frequency, and time-frequency domains. self-organising maps (SOMs), trained with 11 of the 27 variables, were used to extract knowledge about the variable values for each group of patients. Results show that the SOM technique allows to determine the profile of each group of patients, assisting in gaining a deeper understanding of this clinical problem. Additionally, information about the most relevant variables is given by the SOM analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Ergodic theory and visualization. II. Fourier mesochronic plots visualize (quasi)periodic sets.

Science.gov (United States)

Levnajić, Zoran; Mezić, Igor

2015-05-01

We present an application and analysis of a visualization method for measure-preserving dynamical systems introduced by I. Mezić and A. Banaszuk [Physica D 197, 101 (2004)], based on frequency analysis and Koopman operator theory. This extends our earlier work on visualization of ergodic partition [Z. Levnajić and I. Mezić, Chaos 20, 033114 (2010)]. Our method employs the concept of Fourier time average [I. Mezić and A. Banaszuk, Physica D 197, 101 (2004)], and is realized as a computational algorithms for visualization of periodic and quasi-periodic sets in the phase space. The complement of periodic phase space partition contains chaotic zone, and we show how to identify it. The range of method's applicability is illustrated using well-known Chirikov standard map, while its potential in illuminating higher-dimensional dynamics is presented by studying the Froeschlé map and the Extended Standard Map.

Concept Mapping

Science.gov (United States)

Technology & Learning, 2005

2005-01-01

Concept maps are graphical ways of working with ideas and presenting information. They reveal patterns and relationships and help students to clarify their thinking, and to process, organize and prioritize. Displaying information visually--in concept maps, word webs, or diagrams--stimulates creativity. Being able to think logically teaches…

Pulmonary nodule characterization: A comparison of conventional with quantitative and visual semi-quantitative analyses using contrast enhancement maps

International Nuclear Information System (INIS)

Petkovska, Iva; Shah, Sumit K.; McNitt-Gray, Michael F.; Goldin, Jonathan G.; Brown, Matthew S.; Kim, Hyun J.; Brown, Kathleen; Aberle, Denise R.

2006-01-01

Purpose: To determine whether conventional nodule densitometry or analysis based on contrast enhancement maps of indeterminate lung nodules imaged with contrast-enhanced CT can distinguish benign from malignant lung nodules. Materials and method: Thin section, contrast-enhanced CT (baseline, and post-contrast series acquired at 45, 90,180, and 360 s) was performed on 29 patients with indeterminate lung nodules (14 benign, 15 malignant). A thoracic radiologist identified the boundary of each nodule using semi-automated contouring to form a 3D region-of-interest (ROI) on each image series. The post-contrast series having the maximum mean enhancement was then volumetrically registered to the baseline series. The two series were subtracted volumetrically and the subtracted voxels were quantized into seven color-coded bins, forming a contrast enhancement map (CEM). Conventional nodule densitometry was performed to obtain the maximum difference in mean enhancement values for each nodule from a circular ROI. Three thoracic radiologists performed visual semi-quantitative analysis of each nodule, scoring each map for: (a) magnitude and (b) heterogeneity of enhancement throughout the entire volume of the nodule on a five-point scale. Receiver operator characteristic (ROC) analysis was conducted on these features to evaluate their diagnostic efficacy. Finally, 14 quantitative texture features were calculated for each map. A statistical analysis was performed to combine the 14 texture features to a single factor. ROC analysis of the derived aggregate factor was done as an indicator of malignancy. All features were analyzed for differences between benign and malignant nodules. Results: Using 15 HU as a threshold, 93% (14/15) of malignant and 79% (11/14) of benign nodules demonstrated enhancement. The ROC curve when higher values of enhancement indicate malignancy was generated and area under the curve (AUC) was 0.76. The visually scored magnitude of enhancement was found to be

Atlas of knowledge anyone can map

CERN Document Server

Börner, Katy

2015-01-01

Maps of physical spaces locate us in the world and help us navigate unfamiliar routes. Maps of topical spaces help us visualize the extent and structure of our collective knowledge; they reveal bursts of activity, pathways of ideas, and borders that beg to be crossed. This book, from the author of Atlas of Science, describes the power of topical maps, providing readers with principles for visualizing knowledge and offering as examples forty large-scale and more than 100 small-scale full-color maps. Today, data literacy is becoming as important as language literacy. Well-designed visualizations can rescue us from a sea of data, helping us to make sense of information, connect ideas, and make better decisions in real time. In Atlas of Knowledge, leading visualization expert Katy Borner makes the case for a systems science approach to science and technology studies and explains different types and levels of analysis. Drawing on fifteen years of teaching and tool development, she introduces a theoretical framewor...

Participatory Maps

DEFF Research Database (Denmark)

Salovaara-Moring, Inka

2016-01-01

practice. In particular, mapping environmental damage, endangered species, and human-made disasters has become one focal point for environmental knowledge production. This type of digital map has been highlighted as a processual turn in critical cartography, whereas in related computational journalism...... of a geo-visualization within information mapping that enhances embodiment in the experience of the information. InfoAmazonia is defined as a digitally created map-space within which journalistic practice can be seen as dynamic, performative interactions between journalists, ecosystems, space, and species...

Map Learning with a 3D Printed Interactive Small-Scale Model: Improvement of Space and Text Memorization in Visually Impaired Students

Directory of Open Access Journals (Sweden)

Stéphanie Giraud

2017-06-01

Full Text Available Special education teachers for visually impaired students rely on tools such as raised-line maps (RLMs to teach spatial knowledge. These tools do not fully and adequately meet the needs of the teachers because they are long to produce, expensive, and not versatile enough to provide rapid updating of the content. For instance, the same RLM can barely be used during different lessons. In addition, those maps do not provide any interactivity, which reduces students’ autonomy. With the emergence of 3D printing and low-cost microcontrollers, it is now easy to design affordable interactive small-scale models (SSMs which are adapted to the needs of special education teachers. However, no study has previously been conducted to evaluate non-visual learning using interactive SSMs. In collaboration with a specialized teacher, we designed a SSM and a RLM representing the evolution of the geography and history of a fictitious kingdom. The two conditions were compared in a study with 24 visually impaired students regarding the memorization of the spatial layout and historical contents. The study showed that the interactive SSM improved both space and text memorization as compared to the RLM with braille legend. In conclusion, we argue that affordable home-made interactive small scale models can improve learning for visually impaired students. Interestingly, they are adaptable to any teaching situation including students with specific needs.

Map Learning with a 3D Printed Interactive Small-Scale Model: Improvement of Space and Text Memorization in Visually Impaired Students.

Science.gov (United States)

Giraud, Stéphanie; Brock, Anke M; Macé, Marc J-M; Jouffrais, Christophe

2017-01-01

Special education teachers for visually impaired students rely on tools such as raised-line maps (RLMs) to teach spatial knowledge. These tools do not fully and adequately meet the needs of the teachers because they are long to produce, expensive, and not versatile enough to provide rapid updating of the content. For instance, the same RLM can barely be used during different lessons. In addition, those maps do not provide any interactivity, which reduces students' autonomy. With the emergence of 3D printing and low-cost microcontrollers, it is now easy to design affordable interactive small-scale models (SSMs) which are adapted to the needs of special education teachers. However, no study has previously been conducted to evaluate non-visual learning using interactive SSMs. In collaboration with a specialized teacher, we designed a SSM and a RLM representing the evolution of the geography and history of a fictitious kingdom. The two conditions were compared in a study with 24 visually impaired students regarding the memorization of the spatial layout and historical contents. The study showed that the interactive SSM improved both space and text memorization as compared to the RLM with braille legend. In conclusion, we argue that affordable home-made interactive small scale models can improve learning for visually impaired students. Interestingly, they are adaptable to any teaching situation including students with specific needs.

Direct visualization of glutamate transporter elevator mechanism by high-speed AFM.

Science.gov (United States)

Ruan, Yi; Miyagi, Atsushi; Wang, Xiaoyu; Chami, Mohamed; Boudker, Olga; Scheuring, Simon

2017-02-14

Glutamate transporters are essential for recovery of the neurotransmitter glutamate from the synaptic cleft. Crystal structures in the outward- and inward-facing conformations of a glutamate transporter homolog from archaebacterium Pyrococcus horikoshii , sodium/aspartate symporter Glt Ph , suggested the molecular basis of the transporter cycle. However, dynamic studies of the transport mechanism have been sparse and indirect. Here we present high-speed atomic force microscopy (HS-AFM) observations of membrane-reconstituted Glt Ph at work. HS-AFM movies provide unprecedented real-space and real-time visualization of the transport dynamics. Our results show transport mediated by large amplitude 1.85-nm "elevator" movements of the transport domains consistent with previous crystallographic and spectroscopic studies. Elevator dynamics occur in the absence and presence of sodium ions and aspartate, but stall in sodium alone, providing a direct visualization of the ion and substrate symport mechanism. We show unambiguously that individual protomers within the trimeric transporter function fully independently.

The Power of Visual Approaches in Qualitative Inquiry: The Use of Collage Making and Concept Mapping in Experiential Research

Directory of Open Access Journals (Sweden)

Lynn Butler-Kisber

2010-01-01

Full Text Available The burgeoning interest in arts-informed research and the increasing variety of visual possibilities as a result of new technologies have paved the way for researchers to explore and use visual forms of inquiry. This article investigates how collage making and concept mapping are useful visual approaches that can inform qualitative research. They are experiential ways of doing/knowing that help to get at tacit aspects of both understanding and process and to make these more explicit to the researcher and more accessible to audiences. It outlines specific ways that each approach can be used with examples to illustrate how the approach informs the researcher's experience and that of the audience. The two approaches are compared and contrasted and issues that can arise in the work are discussed.

From retinal waves to activity-dependent retinogeniculate map development.

Directory of Open Access Journals (Sweden)

Jeffrey Markowitz

Full Text Available A neural model is described of how spontaneous retinal waves are formed in infant mammals, and how these waves organize activity-dependent development of a topographic map in the lateral geniculate nucleus, with connections from each eye segregated into separate anatomical layers. The model simulates the spontaneous behavior of starburst amacrine cells and retinal ganglion cells during the production of retinal waves during the first few weeks of mammalian postnatal development. It proposes how excitatory and inhibitory mechanisms within individual cells, such as Ca(2+-activated K(+ channels, and cAMP currents and signaling cascades, can modulate the spatiotemporal dynamics of waves, notably by controlling the after-hyperpolarization currents of starburst amacrine cells. Given the critical role of the geniculate map in the development of visual cortex, these results provide a foundation for analyzing the temporal dynamics whereby the visual cortex itself develops.

PhyloGeoViz: a web-based program that visualizes genetic data on maps.

Science.gov (United States)

Tsai, Yi-Hsin E

2011-05-01

The first step of many population genetic studies is the simple visualization of allele frequencies on a landscape. This basic data exploration can be challenging without proprietary software, and the manual plotting of data is cumbersome and unfeasible at large sample sizes. I present an open source, web-based program that plots any kind of frequency or count data as pie charts in Google Maps (Google Inc., Mountain View, CA). Pie polygons are then exportable to Google Earth (Google Inc.), a free Geographic Information Systems platform. Import of genetic data into Google Earth allows phylogeographers access to a wealth of spatial information layers integral to forming hypotheses and understanding patterns in the data. © 2010 Blackwell Publishing Ltd.

Stereoscopic Visualization of Diffusion Tensor Imaging Data: A Comparative Survey of Visualization Techniques

International Nuclear Information System (INIS)

Raslan, O.; Debnam, J.M.; Ketonen, L.; Kumar, A.J.; Schellingerhout, D.; Wang, J.

2013-01-01

Diffusion tensor imaging (DTI) data has traditionally been displayed as a gray scale functional anisotropy map (GSFM) or color coded orientation map (CCOM). These methods use black and white or color with intensity values to map the complex multidimensional DTI data to a two-dimensional image. Alternative visualization techniques, such as V m ax maps utilize enhanced graphical representation of the principal eigenvector by means of a headless arrow on regular non stereoscopic (VM) or stereoscopic display (VMS). A survey of clinical utility of patients with intracranial neoplasms was carried out by 8 neuro radiologists using traditional and nontraditional methods of DTI display. Pairwise comparison studies of 5 intracranial neoplasms were performed with a structured questionnaire comparing GSFM, CCOM, VM, and VMS. Six of 8 neuro radiologists favored V m ax maps over traditional methods of display (GSFM and CCOM). When comparing the stereoscopic (VMS) and the non-stereoscopic (VM) modes, 4 favored VMS, 2 favored VM, and 2 had no preference. In conclusion, processing and visualizing DTI data stereoscopically is technically feasible. An initial survey of users indicated that V m ax based display methodology with or without stereoscopic visualization seems to be preferred over traditional methods to display DTI data.

Fermi surface mapping: Techniques and visualization

International Nuclear Information System (INIS)

Rotenberg, E.; Denlinger, J.D.; Kevan, S.D.

1997-01-01

Angle-resolved photoemission (ARP) of valence bands is a mature technique that has achieved spectacular success in band-mapping metals, semiconductors, and insulators. The purpose of the present study was the development of experimental and analytical techniques in ARP which take advantage of third generation light sources. Here the authors studied the relatively simple Cu surface in preparation for other metals. Copper and related metals themselves are of current interest, especially due to its role as an interlayer in spin valves and other magnetic heterostructures. A major goal of this study was the development of a systematic technique to quickly (i.e. in a few hours of synchrotron beamtime) measure the FS and separate it into bulk and surface FS's. Often, one needs to avoid bulk features altogether, which one can achieve by carefully mapping their locations in k-space. The authors will also show how they systematically map Fermi surfaces throughout large volumes of k-space, and, by processing the resulting volume data sets, provide intuitive pictures of FS's, both bulk and surface

Asymmetrical interhemispheric connections develop in cat visual cortex after early unilateral convergent strabismus: Anatomy, physiology and mechanisms

Directory of Open Access Journals (Sweden)

Emmanuel eBui Quoc

2012-01-01

Full Text Available In the mammalian primary visual cortex, the corpus callosum contributes to the unification of the visual hemifields that project to the two hemispheres. Its development depends on visual experience. When the latter is abnormal, callosal connections must undergo dramatic anatomical and physiological changes. However, such data are sparse and incomplete. Thus, little is known about the consequences of abnormal postnatal visual experience on the development of callosal connections and their role in unifying representation of the two hemifields. Here, the effects of early unilateral convergent strabismus (a model of abnormal visual experience were fully characterized with respect to the development of the callosal connections in cat visual cortex, an experimental model for humans. Electrophysiological responses and 3D reconstruction of single callosal axons show that abnormally asymmetrical callosal connections develop after unilateral convergent strabismus, resulting from an extension of axonal branches of specific orders in the hemisphere ipsilateral to the deviated eye and a decreased number of nodes and terminals in the other (ipsilateral to the non deviated eye. Furthermore this asymmetrical organization prevents the establishment of a unifying representation of the two visual hemifields. As a general rule, we suggest that crossed and uncrossed retino-geniculo-cortical pathways contribute in succession to the development of the callosal maps in visual cortex.

Combined visualization for noise mapping of industrial facilities based on ray-tracing and thin plate splines

Science.gov (United States)

Ovsiannikov, Mikhail; Ovsiannikov, Sergei

2017-01-01

The paper presents the combined approach to noise mapping and visualizing of industrial facilities sound pollution using forward ray tracing method and thin-plate spline interpolation. It is suggested to cauterize industrial area in separate zones with similar sound levels. Equivalent local source is defined for range computation of sanitary zones based on ray tracing algorithm. Computation of sound pressure levels within clustered zones are based on two-dimension spline interpolation of measured data on perimeter and inside the zone.

Dynamic plasticity in coupled avian midbrain maps

Science.gov (United States)

Atwal, Gurinder Singh

2004-12-01

Internal mapping of the external environment is carried out using the receptive fields of topographic neurons in the brain, and in a normal barn owl the aural and visual subcortical maps are aligned from early experiences. However, instantaneous misalignment of the aural and visual stimuli has been observed to result in adaptive behavior, manifested by functional and anatomical changes of the auditory processing system. Using methods of information theory and statistical mechanics a model of the adaptive dynamics of the aural receptive field is presented and analyzed. The dynamics is determined by maximizing the mutual information between the neural output and the weighted sensory neural inputs, admixed with noise, subject to biophysical constraints. The reduced costs of neural rewiring, as in the case of young barn owls, reveal two qualitatively different types of receptive field adaptation depending on the magnitude of the audiovisual misalignment. By letting the misalignment increase with time, it is shown that the ability to adapt can be increased even when neural rewiring costs are high, in agreement with recent experimental reports of the increased plasticity of the auditory space map in adult barn owls due to incremental learning. Finally, a critical speed of misalignment is identified, demarcating the crossover from adaptive to nonadaptive behavior.

To be selected or not to be selected : a modeling and behavioral study of the mechanisms underlying stimulus-driven and top-down visual attention

NARCIS (Netherlands)

Voort van der Kleij, van der Gwendid T.

2007-01-01

This thesis investigates the mechanisms of stimulus-driven visual attention (global saliency), the mechanisms of top-down visual attention, and the interaction between these mechanisms, in visual search. Following the outline of an existing model of top-down visual attention, namely the Closed-Loop

Neural computation of visual imaging based on Kronecker product in the primary visual cortex

Directory of Open Access Journals (Sweden)

Guozheng Yao

2010-03-01

that the function of cortical column in cortex V1 is considered as the basic unit of visual image processing (such unit can implement basic multiplication of visual primitives, such as contour, line, and edge, rather than a set of tiled array filter. Fourier Transformation is replaced with Kronecker product, which greatly reduces the computational complexity. The neurobiological basis of this idea is that a visual image can be represented as a linear combination of orderly orthogonal primitive image containing some local feature. In the visual pathway, the image patches are topographically mapped onto cortex V1 through parallel multi-channels and then are processed independently by functional columns. Clearly, the above new perspective has some reference significance to exploring the neural mechanisms on the human visual information processing.

Visualizing the Logistic Map with a Microcontroller

Science.gov (United States)

Serna, Juan D.; Joshi, Amitabh

2012-01-01

The logistic map is one of the simplest nonlinear dynamical systems that clearly exhibits the route to chaos. In this paper, we explore the evolution of the logistic map using an open-source microcontroller connected to an array of light-emitting diodes (LEDs). We divide the one-dimensional domain interval [0,1] into ten equal parts, an associate…

Development of a competency mapping tool for undergraduate professional degree programmes, using mechanical engineering as a case study

Science.gov (United States)

Holmes, David W.; Sheehan, Madoc; Birks, Melanie; Smithson, John

2018-01-01

Mapping the curriculum of a professional degree to the associated competency standard ensures graduates have the competence to perform as professionals. Existing approaches to competence mapping vary greatly in depth, complexity, and effectiveness, and a standardised approach remains elusive. This paper describes a new mapping software tool that streamlines and standardises the competency mapping process. The available analytics facilitate ongoing programme review, management, and accreditation. The complete mapping and analysis of an Australian mechanical engineering degree programme is described as a case study. Each subject is mapped by evaluating the amount and depth of competence development present. Combining subject results then enables highly detailed programme level analysis. The mapping process is designed to be administratively light, with aspects of professional development embedded in the software. The effective competence mapping described in this paper enables quantification of learning within a professional degree programme, and provides a mechanism for holistic programme improvement.

Diagnosis of regional cerebral blood flow abnormalities using SPECT: agreement between individualized statistical parametric maps and visual inspection by nuclear medicine physicians with different levels of expertise in nuclear neurology

Energy Technology Data Exchange (ETDEWEB)

Rocha, Euclides Timoteo da, E-mail: euclidestimoteo@uol.com.b [Fundacao Pio XII, Barretos, SP (Brazil). Hospital de Cancer. Dept. de Medicina Nuclear; Buchpiguel, Carlos Alberto [Hospital do Coracao, Sao Paulo, SP (Brazil). Dept. de Medicina Nuclear; Nitrini, Ricardo [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Neurologia; Tazima, Sergio [Hospital Alemao Oswaldo Cruz (HAOC), Sao Paulo, SP (Brazil). Dept. de Medicina Nuclear; Peres, Stela Verzinhase [Fundacao Pio XII, Barretos, SP (Brazil). Hospital de Cancer; Busatto Filho, Geraldo [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Div. de Medicina Nuclear

2009-07-01

Introduction: visual analysis is widely used to interpret regional cerebral blood flow (rCBF) SPECT images in clinical practice despite its limitations. Automated methods are employed to investigate between-group rCBF differences in research studies but have rarely been explored in individual analyses. Objectives: to compare visual inspection by nuclear physicians with the automated statistical parametric mapping program using a SPECT dataset of patients with neurological disorders and normal control images. Methods: using statistical parametric mapping, 14 SPECT images from patients with various neurological disorders were compared individually with a databank of 32 normal images using a statistical threshold of p<0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). Statistical parametric mapping results were compared with visual analyses by a nuclear physician highly experienced in neurology (A) as well as a nuclear physician with a general background of experience (B) who independently classified images as normal or altered, and determined the location of changes and the severity. Results: of the 32 images of the normal databank, 4 generated maps showing rCBF abnormalities (p<0.05, corrected). Among the 14 images from patients with neurological disorders, 13 showed rCBF alterations. Statistical parametric mapping and physician A completely agreed on 84.37% and 64.28% of cases from the normal databank and neurological disorders, respectively. The agreement between statistical parametric mapping and ratings of physician B were lower (71.18% and 35.71%, respectively). Conclusion: statistical parametric mapping replicated the findings described by the more experienced nuclear physician. This finding suggests that automated methods for individually analyzing rCBF SPECT images may be a valuable resource to complement visual inspection in clinical practice. (author)

MAPS of Cancer

Science.gov (United States)

Gray, Lincoln

1998-01-01

Our goal was to produce an interactive visualization from a mathematical model that successfully predicts metastases from head and neck cancer. We met this goal early in the project. The visualization is available for the public to view. Our work appears to fill a need for more information about this deadly disease. The idea of this project was to make an easily interpretable visualization based on what we call "functional maps" of disease. A functional map is a graphic summary of medical data, where distances between parts of the body are determined by the probability of disease, not by anatomical distances. Functional maps often beat little resemblance to anatomical maps, but they can be used to predict the spread of disease. The idea of modeling the spread of disease in an abstract multidimensional space is difficult for many people. Our goal was to make the important predictions easy to see. NASA must face this problem frequently: how to help laypersons and professionals see important trends in abstract, complex data. We took advantage of concepts perfected in NASA's graphics libraries. As an analogy, consider a functional map of early America. Suppose we choose travel times, rather than miles, as our measures of inter-city distances. For Abraham Lincoln, travel times would have been the more meaningful measure of separation between cities. In such a map New Orleans would be close to Memphis because of the Mississippi River. St. Louis would be close to Portland because of the Oregon Trail. Oklahoma City would be far from Little Rock because of the Cheyenne. Such a map would look puzzling to those of us who have always seen physical maps, but the functional map would be more useful in predicting the probabilities of inter-site transit. Continuing the analogy, we could predict the spread of social diseases such as gambling along the rivers and cattle rustling along the trails. We could simply print the functional map of America, but it would be more interesting

Mapping with Drupal

CERN Document Server

Palazzolo, Alan

2011-01-01

Build beautiful interactive maps on your Drupal website, and tell engaging visual stories with your data. This concise guide shows you how to create custom geographical maps from top to bottom, using Drupal 7 tools and out-of-the-box modules. You'll learn how mapping works in Drupal, with examples on how to use intuitive interfaces to map local events, businesses, groups, and other custom data. Although building maps with Drupal can be tricky, this book helps you navigate the system's complexities for creating sophisticated maps that match your site design. Get the knowledge and tools you ne

Mapping scientific frontiers the quest for knowledge visualization

CERN Document Server

Chen, Chaomei

2013-01-01

In its revised edition, this book examines the history and current developments in knowledge visualization from an interdisciplinary perspective, from theories of invisible colleges and competing paradigms to practical applications of visualization techniques.

The Arctic Research Mapping Application (ARMAP): a Geoportal for Visualizing Project-level Information About U.S. Funded Research in the Arctic

Science.gov (United States)

Kassin, A.; Cody, R. P.; Barba, M.; Gaylord, A. G.; Manley, W. F.; Score, R.; Escarzaga, S. M.; Tweedie, C. E.

2016-12-01

The Arctic Research Mapping Application (ARMAP; http://armap.org/) is a suite of online applications and data services that support Arctic science by providing project tracking information (who's doing what, when and where in the region) for United States Government funded projects. In collaboration with 17 research agencies, project locations are displayed in a visually enhanced web mapping application. Key information about each project is presented along with links to web pages that provide additional information, including links to data where possible. The latest ARMAP iteration has i) reworked the search user interface (UI) to enable multiple filters to be applied in user-driven queries and ii) implemented ArcGIS Javascript API 4.0 to allow for deployment of 3D maps directly into a users web-browser and enhanced customization of popups. Module additions include i) a dashboard UI powered by a back-end Apache SOLR engine to visualize data in intuitive and interactive charts; and ii) a printing module that allows users to customize maps and export these to different formats (pdf, ppt, gif and jpg). New reference layers and an updated ship tracks layer have also been added. These improvements have been made to improve discoverability, enhance logistics coordination, identify geographic gaps in research/observation effort, and foster enhanced collaboration among the research community. Additionally, ARMAP can be used to demonstrate past, present, and future research effort supported by the U.S. Government.

Visual Semiotics & Uncertainty Visualization: An Empirical Study.

Science.gov (United States)

MacEachren, A M; Roth, R E; O'Brien, J; Li, B; Swingley, D; Gahegan, M

2012-12-01

This paper presents two linked empirical studies focused on uncertainty visualization. The experiments are framed from two conceptual perspectives. First, a typology of uncertainty is used to delineate kinds of uncertainty matched with space, time, and attribute components of data. Second, concepts from visual semiotics are applied to characterize the kind of visual signification that is appropriate for representing those different categories of uncertainty. This framework guided the two experiments reported here. The first addresses representation intuitiveness, considering both visual variables and iconicity of representation. The second addresses relative performance of the most intuitive abstract and iconic representations of uncertainty on a map reading task. Combined results suggest initial guidelines for representing uncertainty and discussion focuses on practical applicability of results.

Recovery Action Mapping Tool

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Recovery Action Mapping Tool is a web map that allows users to visually interact with and query actions that were developed to recover species listed under the...

Improvement in Visual Search with Practice : Mapping Learning-Related Changes in Neurocognitive Stages of Processing

NARCIS (Netherlands)

Clark, Kait; Appelbaum, L. Gregory; van den Berg, Berry; Mitroff, Stephen R.; Woldorff, Marty G.

2015-01-01

Practice can improve performance on visual search tasks; the neural mechanisms underlying such improvements, however, are not clear. Response time typically shortens with practice, but which components of the stimulus-response processing chain facilitate this behavioral change? Improved search

Introducing memory and association mechanism into a biologically inspired visual model.

Science.gov (United States)

Qiao, Hong; Li, Yinlin; Tang, Tang; Wang, Peng

2014-09-01

A famous biologically inspired hierarchical model (HMAX model), which was proposed recently and corresponds to V1 to V4 of the ventral pathway in primate visual cortex, has been successfully applied to multiple visual recognition tasks. The model is able to achieve a set of position- and scale-tolerant recognition, which is a central problem in pattern recognition. In this paper, based on some other biological experimental evidence, we introduce the memory and association mechanism into the HMAX model. The main contributions of the work are: 1) mimicking the active memory and association mechanism and adding the top down adjustment to the HMAX model, which is the first try to add the active adjustment to this famous model and 2) from the perspective of information, algorithms based on the new model can reduce the computation storage and have a good recognition performance. The new model is also applied to object recognition processes. The primary experimental results show that our method is efficient with a much lower memory requirement.

Assessment and visualization of uncertainty for countrywide soil organic matter map of Hungary using local entropy

Science.gov (United States)

Szatmári, Gábor; Pásztor, László

2016-04-01

Uncertainty is a general term expressing our imperfect knowledge in describing an environmental process and we are aware of it (Bárdossy and Fodor, 2004). Sampling, laboratory measurements, models and so on are subject to uncertainty. Effective quantification and visualization of uncertainty would be indispensable to stakeholders (e.g. policy makers, society). Soil related features and their spatial models should be stressfully targeted to uncertainty assessment because their inferences are further used in modelling and decision making process. The aim of our present study was to assess and effectively visualize the local uncertainty of the countrywide soil organic matter (SOM) spatial distribution model of Hungary using geostatistical tools and concepts. The Hungarian Soil Information and Monitoring System's SOM data (approximately 1,200 observations) and environmental related, spatially exhaustive secondary information (i.e. digital elevation model, climatic maps, MODIS satellite images and geological map) were used to model the countrywide SOM spatial distribution by regression kriging. It would be common to use the calculated estimation (or kriging) variance as a measure of uncertainty, however the normality and homoscedasticity hypotheses have to be refused according to our preliminary analysis on the data. Therefore, a normal score transformation and a sequential stochastic simulation approach was introduced to be able to model and assess the local uncertainty. Five hundred equally probable realizations (i.e. stochastic images) were generated. The number of the stochastic images is fairly enough to provide a model of uncertainty at each location, which is a complete description of uncertainty in geostatistics (Deutsch and Journel, 1998). Furthermore, these models can be applied e.g. to contour the probability of any events, which can be regarded as goal oriented digital soil maps and are of interest for agricultural management and decision making as well. A

Large Scale Landform Mapping Using Lidar DEM

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Türkay Gökgöz

2015-08-01

Full Text Available In this study, LIDAR DEM data was used to obtain a primary landform map in accordance with a well-known methodology. This primary landform map was generalized using the Focal Statistics tool (Majority, considering the minimum area condition in cartographic generalization in order to obtain landform maps at 1:1000 and 1:5000 scales. Both the primary and the generalized landform maps were verified visually with hillshaded DEM and an orthophoto. As a result, these maps provide satisfactory visuals of the landforms. In order to show the effect of generalization, the area of each landform in both the primary and the generalized maps was computed. Consequently, landform maps at large scales could be obtained with the proposed methodology, including generalization using LIDAR DEM.

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks.

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Ruiz-Rizzo, Adriana L; Neitzel, Julia; Müller, Hermann J; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's "theory of visual attention" (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks

Science.gov (United States)

Ruiz-Rizzo, Adriana L.; Neitzel, Julia; Müller, Hermann J.; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks

Directory of Open Access Journals (Sweden)

Adriana L. Ruiz-Rizzo

2018-03-01

Full Text Available Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity and selectivity functions (i.e., top-down control and spatial laterality. However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI. Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable

Drawing Road Networks with Mental Maps.

Science.gov (United States)

Lin, Shih-Syun; Lin, Chao-Hung; Hu, Yan-Jhang; Lee, Tong-Yee

2014-09-01

Tourist and destination maps are thematic maps designed to represent specific themes in maps. The road network topologies in these maps are generally more important than the geometric accuracy of roads. A road network warping method is proposed to facilitate map generation and improve theme representation in maps. The basic idea is deforming a road network to meet a user-specified mental map while an optimization process is performed to propagate distortions originating from road network warping. To generate a map, the proposed method includes algorithms for estimating road significance and for deforming a road network according to various geometric and aesthetic constraints. The proposed method can produce an iconic mark of a theme from a road network and meet a user-specified mental map. Therefore, the resulting map can serve as a tourist or destination map that not only provides visual aids for route planning and navigation tasks, but also visually emphasizes the presentation of a theme in a map for the purpose of advertising. In the experiments, the demonstrations of map generations show that our method enables map generation systems to generate deformed tourist and destination maps efficiently.

Visual saliency in MPEG-4 AVC video stream

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Ammar, M.; Mitrea, M.; Hasnaoui, M.; Le Callet, P.

2015-03-01

Visual saliency maps already proved their efficiency in a large variety of image/video communication application fields, covering from selective compression and channel coding to watermarking. Such saliency maps are generally based on different visual characteristics (like color, intensity, orientation, motion,…) computed from the pixel representation of the visual content. This paper resumes and extends our previous work devoted to the definition of a saliency map solely extracted from the MPEG-4 AVC stream syntax elements. The MPEG-4 AVC saliency map thus defined is a fusion of static and dynamic map. The static saliency map is in its turn a combination of intensity, color and orientation features maps. Despite the particular way in which all these elementary maps are computed, the fusion techniques allowing their combination plays a critical role in the final result and makes the object of the proposed study. A total of 48 fusion formulas (6 for combining static features and, for each of them, 8 to combine static to dynamic features) are investigated. The performances of the obtained maps are evaluated on a public database organized at IRCCyN, by computing two objective metrics: the Kullback-Leibler divergence and the area under curve.

Rendering Systems Visible for Design: Synthesis Maps as Constructivist Design Narratives

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Peter Jones

Full Text Available Synthesis maps integrate research evidence, system expertise, and design proposals into visual narratives. These narratives support communication and decision-making among stakeholders. Synthesis maps evolved from earlier visualization tools in systemics and design. They help stakeholders to understand design options for complex sociotechnical systems. Other visual approaches map complexity for effective collaboration across perspectives and knowledge domains. These help stakeholder groups to work in higher-order design contexts for sociotechnical or human-ecological systems. This article describes a constructivist pedagogy for collaborative learning in small teams of mixed-discipline designers. Synthesis mapping enables these teams to learn systems methods for design research in complex problem domains. Synthesis maps integrate knowledge from research cycles and iterative sensemaking to define a coherent design narrative. While synthesis maps may include formal system modeling techniques, they do not require them. Synthesis maps tangibly render research observations and design choices. As a hybrid system design method, synthesis maps are a contribution to the design genre of visual systems thinking.

Short-term retention of visual information: Evidence in support of feature-based attention as an underlying mechanism.

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Sneve, Markus H; Sreenivasan, Kartik K; Alnæs, Dag; Endestad, Tor; Magnussen, Svein

2015-01-01

Retention of features in visual short-term memory (VSTM) involves maintenance of sensory traces in early visual cortex. However, the mechanism through which this is accomplished is not known. Here, we formulate specific hypotheses derived from studies on feature-based attention to test the prediction that visual cortex is recruited by attentional mechanisms during VSTM of low-level features. Functional magnetic resonance imaging (fMRI) of human visual areas revealed that neural populations coding for task-irrelevant feature information are suppressed during maintenance of detailed spatial frequency memory representations. The narrow spectral extent of this suppression agrees well with known effects of feature-based attention. Additionally, analyses of effective connectivity during maintenance between retinotopic areas in visual cortex show that the observed highlighting of task-relevant parts of the feature spectrum originates in V4, a visual area strongly connected with higher-level control regions and known to convey top-down influence to earlier visual areas during attentional tasks. In line with this property of V4 during attentional operations, we demonstrate that modulations of earlier visual areas during memory maintenance have behavioral consequences, and that these modulations are a result of influences from V4. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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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.

Mapping a Difference: The Power of Geospatial Visualization

Science.gov (United States)

Kolvoord, B.

2015-12-01

Geospatial Technologies (GST), such as GIS, GPS and remote sensing, offer students and teachers the opportunity to study the "why" of where. By making maps and collecting location-based data, students can pursue authentic problems using sophisticated tools. The proliferation of web- and cloud-based tools has made these technologies broadly accessible to schools. In addition, strong spatial thinking skills have been shown to be a key factor in supporting students that want to study science, technology, engineering, and mathematics (STEM) disciplines (Wai, Lubinski and Benbow) and pursue STEM careers. Geospatial technologies strongly scaffold the development of these spatial thinking skills. For the last ten years, the Geospatial Semester, a unique dual-enrollment partnership between James Madison University and Virginia high schools, has provided students with the opportunity to use GST's to hone their spatial thinking skills and to do extended projects of local interest, including environmental, geological and ecological studies. Along with strong spatial thinking skills, these students have also shown strong problem solving skills, often beyond those of fellow students in AP classes. Programs like the Geospatial Semester are scalable and within the reach of many college and university departments, allowing strong engagement with K-12 schools. In this presentation, we'll share details of the Geospatial Semester and research results on the impact of the use of these technologies on students' spatial thinking skills, and discuss the success and challenges of developing K-12 partnerships centered on geospatial visualization.

Personalized 2D color maps

KAUST Repository

Waldin, Nicholas

2016-06-24

2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. In this paper we present a novel method to measure a user\\'s ability to distinguish colors of a two-dimensional color map on a given monitor. We show how to adapt the color map to the user and display to optimally compensate for the measured deficiencies. Furthermore, we improve user acceptance of the calibration procedure by transforming the calibration into a game. The user has to sort colors along a line in a 3D color space in a competitive fashion. The errors the user makes in sorting these lines are used to adapt the color map to his perceptual capabilities.

Visualizing fossilization using laser ablation-inductively coupled plasma-mass spectrometry maps of trace elements in Late Cretaceous bones

Science.gov (United States)

Koenig, A.E.; Rogers, R.R.; Trueman, C.N.

2009-01-01

Elemental maps generated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) provide a previously unavailable high-resolution visualization of the complex physicochemical conditions operating within individual bones during the early stages of diagenesis and fossilization. A selection of LA-ICP-MS maps of bones collected from the Late Cretaceous of Montana (United States) and Madagascar graphically illustrate diverse paths to recrystallization, and reveal unique insights into geochemical aspects of taphonomic history. Some bones show distinct gradients in concentrations of rare earth elements and uranium, with highest concentrations at external bone margins. Others exhibit more intricate patterns of trace element uptake related to bone histology and its control on the flow paths of pore waters. Patterns of element uptake as revealed by LA-ICP-MS maps can be used to guide sampling strategies, and call into question previous studies that hinge upon localized bulk samples of fossilized bone tissue. LA-ICP-MS maps also allow for comparison of recrystallization rates among fossil bones, and afford a novel approach to identifying bones or regions of bones potentially suitable for extracting intact biogeochemical signals. ?? 2009 Geological Society of America.

Exploring the molecular mechanisms of Traditional Chinese Medicine components using gene expression signatures and connectivity map.

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Yoo, Minjae; Shin, Jimin; Kim, Hyunmin; Kim, Jihye; Kang, Jaewoo; Tan, Aik Choon

2018-04-04

Traditional Chinese Medicine (TCM) has been practiced over thousands of years in China and other Asian countries for treating various symptoms and diseases. However, the underlying molecular mechanisms of TCM are poorly understood, partly due to the "multi-component, multi-target" nature of TCM. To uncover the molecular mechanisms of TCM, we perform comprehensive gene expression analysis using connectivity map. We interrogated gene expression signatures obtained 102 TCM components using the next generation Connectivity Map (CMap) resource. We performed systematic data mining and analysis on the mechanism of action (MoA) of these TCM components based on the CMap results. We clustered the 102 TCM components into four groups based on their MoAs using next generation CMap resource. We performed gene set enrichment analysis on these components to provide additional supports for explaining these molecular mechanisms. We also provided literature evidence to validate the MoAs identified through this bioinformatics analysis. Finally, we developed the Traditional Chinese Medicine Drug Repurposing Hub (TCM Hub) - a connectivity map resource to facilitate the elucidation of TCM MoA for drug repurposing research. TCMHub is freely available in http://tanlab.ucdenver.edu/TCMHub. Molecular mechanisms of TCM could be uncovered by using gene expression signatures and connectivity map. Through this analysis, we identified many of the TCM components possess diverse MoAs, this may explain the applications of TCM in treating various symptoms and diseases. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Synaptic Mechanisms of Activity-Dependent Remodeling in Visual Cortex during Monocular Deprivation

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Cynthia D. Rittenhouse

2009-01-01

Full Text Available It has long been appreciated that in the visual cortex, particularly within a postnatal critical period for experience-dependent plasticity, the closure of one eye results in a shift in the responsiveness of cortical cells toward the experienced eye. While the functional aspects of this ocular dominance shift have been studied for many decades, their cortical substrates and synaptic mechanisms remain elusive. Nonetheless, it is becoming increasingly clear that ocular dominance plasticity is a complex phenomenon that appears to have an early and a late component. Early during monocular deprivation, deprived eye cortical synapses depress, while later during the deprivation open eye synapses potentiate. Here we review current literature on the cortical mechanisms of activity-dependent plasticity in the visual system during the critical period. These studies shed light on the role of activity in shaping neuronal structure and function in general and can lead to insights regarding how learning is acquired and maintained at the neuronal level during normal and pathological brain development.

Second Hopf map and supersymmetric mechanics with Yang monopole

International Nuclear Information System (INIS)

Gonzales, M.; Toppan, F.; Kuznetsova, Z.; Nersessian, F.; Yeghikyan, V.

2009-01-01

We propose to use the second Hopf map for the reduction (via SU(2) group action) of the eight-dimensional supersymmetric mechanics to five-dimensional supersymmetric systems specified by the presence of an SU(2) Yang monopole. For our purpose we develop the relevant Lagrangian reduction procedure. The reduced system is characterized by its invariance under the N = 5 or N = 4 supersymmetry generators (with or without an additional conserved BRST charge operator) which commute with the su(2) generators. (author)

Perception and psychological evaluation for visual and auditory environment based on the correlation mechanisms

Science.gov (United States)

Fujii, Kenji

2002-06-01

In this dissertation, the correlation mechanism in modeling the process in the visual perception is introduced. It has been well described that the correlation mechanism is effective for describing subjective attributes in auditory perception. The main result is that it is possible to apply the correlation mechanism to the process in temporal vision and spatial vision, as well as in audition. (1) The psychophysical experiment was performed on subjective flicker rates for complex waveforms. A remarkable result is that the phenomenon of missing fundamental is found in temporal vision as analogous to the auditory pitch perception. This implies the existence of correlation mechanism in visual system. (2) For spatial vision, the autocorrelation analysis provides useful measures for describing three primary perceptual properties of visual texture: contrast, coarseness, and regularity. Another experiment showed that the degree of regularity is a salient cue for texture preference judgment. (3) In addition, the autocorrelation function (ACF) and inter-aural cross-correlation function (IACF) were applied for analysis of the temporal and spatial properties of environmental noise. It was confirmed that the acoustical properties of aircraft noise and traffic noise are well described. These analyses provided useful parameters extracted from the ACF and IACF in assessing the subjective annoyance for noise. Thesis advisor: Yoichi Ando Copies of this thesis written in English can be obtained from Junko Atagi, 6813 Mosonou, Saijo-cho, Higashi-Hiroshima 739-0024, Japan. E-mail address: atagi\\@urban.ne.jp.

Visual cognition

Energy Technology Data Exchange (ETDEWEB)

Pinker, S.

1985-01-01

This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

Circuit Mechanisms Governing Local vs. Global Motion Processing in Mouse Visual Cortex

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Rune Rasmussen

2017-12-01

Full Text Available A withstanding question in neuroscience is how neural circuits encode representations and perceptions of the external world. A particularly well-defined visual computation is the representation of global object motion by pattern direction-selective (PDS cells from convergence of motion of local components represented by component direction-selective (CDS cells. However, how PDS and CDS cells develop their distinct response properties is still unresolved. The visual cortex of the mouse is an attractive model for experimentally solving this issue due to the large molecular and genetic toolbox available. Although mouse visual cortex lacks the highly ordered orientation columns of primates, it is organized in functional sub-networks and contains striate- and extrastriate areas like its primate counterparts. In this Perspective article, we provide an overview of the experimental and theoretical literature on global motion processing based on works in primates and mice. Lastly, we propose what types of experiments could illuminate what circuit mechanisms are governing cortical global visual motion processing. We propose that PDS cells in mouse visual cortex appear as the perfect arena for delineating and solving how individual sensory features extracted by neural circuits in peripheral brain areas are integrated to build our rich cohesive sensory experiences.

Mapping online consumer search

NARCIS (Netherlands)

Bronnenberg, B.J.; Kim, J.; Albuquerque, P.

2011-01-01

The authors propose a new method to visualize browsing behavior in so-called product search maps. Manufacturers can use these maps to understand how consumers search for competing products before choice, including how information acquisition and product search are organized along brands, product

Visual agnosia and focal brain injury.

Science.gov (United States)

Martinaud, O

Visual agnosia encompasses all disorders of visual recognition within a selective visual modality not due to an impairment of elementary visual processing or other cognitive deficit. Based on a sequential dichotomy between the perceptual and memory systems, two different categories of visual object agnosia are usually considered: 'apperceptive agnosia' and 'associative agnosia'. Impaired visual recognition within a single category of stimuli is also reported in: (i) visual object agnosia of the ventral pathway, such as prosopagnosia (for faces), pure alexia (for words), or topographagnosia (for landmarks); (ii) visual spatial agnosia of the dorsal pathway, such as cerebral akinetopsia (for movement), or orientation agnosia (for the placement of objects in space). Focal brain injuries provide a unique opportunity to better understand regional brain function, particularly with the use of effective statistical approaches such as voxel-based lesion-symptom mapping (VLSM). The aim of the present work was twofold: (i) to review the various agnosia categories according to the traditional visual dual-pathway model; and (ii) to better assess the anatomical network underlying visual recognition through lesion-mapping studies correlating neuroanatomical and clinical outcomes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Probabilistic Mapping of Human Visual Attention from Head Pose Estimation

Directory of Open Access Journals (Sweden)

Andrea Veronese

2017-10-01

Full Text Available Effective interaction between a human and a robot requires the bidirectional perception and interpretation of actions and behavior. While actions can be identified as a directly observable activity, this might not be sufficient to deduce actions in a scene. For example, orienting our face toward a book might suggest the action toward “reading.” For a human observer, this deduction requires the direction of gaze, the object identified as a book and the intersection between gaze and book. With this in mind, we aim to estimate and map human visual attention as directed to a scene, and assess how this relates to the detection of objects and their related actions. In particular, we consider human head pose as measurement to infer the attention of a human engaged in a task and study which prior knowledge should be included in such a detection system. In a user study, we show the successful detection of attention to objects in a typical office task scenario (i.e., reading, working with a computer, studying an object. Our system requires a single external RGB camera for head pose measurements and a pre-recorded 3D point cloud of the environment.

Linking retinotopic fMRI mapping and anatomical probability maps of human occipital areas V1 and V2.

Science.gov (United States)

Wohlschläger, A M; Specht, K; Lie, C; Mohlberg, H; Wohlschläger, A; Bente, K; Pietrzyk, U; Stöcker, T; Zilles, K; Amunts, K; Fink, G R

2005-05-15

Using functional MRI, we characterized field sign maps of the occipital cortex and created three-dimensional maps of these areas. By averaging the individual maps into group maps, probability maps of functionally defined V1 or V2 were determined and compared to anatomical probability maps of Brodmann areas BA17 and BA18 derived from cytoarchitectonic analysis (Amunts, K., Malikovic, A., Mohlberg, H., Schormann, T., Zilles, K., 2000. Brodmann's areas 17 and 18 brought into stereotaxic space-where and how variable? NeuroImage 11, 66-84). Comparison of areas BA17/V1 and BA18/V2 revealed good agreement of the anatomical and functional probability maps. Taking into account that our functional stimulation (due to constraints of the visual angle of stimulation achievable in the MR scanner) only identified parts of V1 and V2, for statistical evaluation of the spatial correlation of V1 and BA17, or V2 and BA18, respectively, the a priori measure kappa was calculated testing the hypothesis that a region can only be part of functionally defined V1 or V2 if it is also in anatomically defined BA17 or BA18, respectively. kappa = 1 means the hypothesis is fully true, kappa = 0 means functionally and anatomically defined visual areas are independent. When applying this measure to the probability maps, kappa was equal to 0.84 for both V1/BA17 and V2/BA18. The data thus show a good correspondence of functionally and anatomically derived segregations of early visual processing areas and serve as a basis for employing anatomical probability maps of V1 and V2 in group analyses to characterize functional activations of early visual processing areas.

State Recognition and Visualization of Hoisting Motor of Quayside Container Crane Based on SOFM

Science.gov (United States)

Yang, Z. Q.; He, P.; Tang, G.; Hu, X.

2017-07-01

The neural network structure and algorithm of self-organizing feature map (SOFM) are researched and analysed. The method is applied to state recognition and visualization of the quayside container crane hoisting motor. By using SOFM, the clustering and visualization of attribute reduction of data are carried out, and three kinds motor states are obtained with Root Mean Square(RMS), Impulse Index and Margin Index, and the simulation visualization interface is realized by MATLAB. Through the processing of the sample data, it can realize the accurate identification of the motor state, thus provide better monitoring of the quayside container crane hoisting motor and a new way for the mechanical state recognition.

Auditory and visual interactions between the superior and inferior colliculi in the ferret.

Science.gov (United States)

Stitt, Iain; Galindo-Leon, Edgar; Pieper, Florian; Hollensteiner, Karl J; Engler, Gerhard; Engel, Andreas K

2015-05-01

The integration of visual and auditory spatial information is important for building an accurate perception of the external world, but the fundamental mechanisms governing such audiovisual interaction have only partially been resolved. The earliest interface between auditory and visual processing pathways is in the midbrain, where the superior (SC) and inferior colliculi (IC) are reciprocally connected in an audiovisual loop. Here, we investigate the mechanisms of audiovisual interaction in the midbrain by recording neural signals from the SC and IC simultaneously in anesthetized ferrets. Visual stimuli reliably produced band-limited phase locking of IC local field potentials (LFPs) in two distinct frequency bands: 6-10 and 15-30 Hz. These visual LFP responses co-localized with robust auditory responses that were characteristic of the IC. Imaginary coherence analysis confirmed that visual responses in the IC were not volume-conducted signals from the neighboring SC. Visual responses in the IC occurred later than retinally driven superficial SC layers and earlier than deep SC layers that receive indirect visual inputs, suggesting that retinal inputs do not drive visually evoked responses in the IC. In addition, SC and IC recording sites with overlapping visual spatial receptive fields displayed stronger functional connectivity than sites with separate receptive fields, indicating that visual spatial maps are aligned across both midbrain structures. Reciprocal coupling between the IC and SC therefore probably serves the dynamic integration of visual and auditory representations of space. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Algorithms for necklace maps

NARCIS (Netherlands)

Speckmann, B.; Verbeek, K.A.B.

2015-01-01

Necklace maps visualize quantitative data associated with regions by placing scaled symbols, usually disks, without overlap on a closed curve (the necklace) surrounding the map regions. Each region is projected onto an interval on the necklace that contains its symbol. In this paper we address the

ANLIZE: a molecular mechanics force field visualization tool and its application to 18-crown-6.

Science.gov (United States)

Stolworthy, L D; Shirts, R B

1997-03-01

We describe a software tool that allows one to visualize and analyze the importance of each individual steric interaction in a molecular mechanics force field. ANLIZE is presently implemented for the Dreiding force field for use with the Cerius2 software package, but could be implemented in any molecular mechanics package with a graphical user interface. ANLIZE calculates individual interactions in the force field, sorts them by size, and displays them in several ways from a menu of choices. This allows the user to scan through selected interactions to visualize which interactions are the primary determinants of preferred conformations. The features of ANLIZE are illustrated using 18-crown-6 as an example, and the factors governing conformational preference in 18-crown-6 are demonstrated. Users of molecular mechanics packages are encouraged to demand this functionality from commercial software producers.

Diffusion-Based Density-Equalizing Maps: an Interdisciplinary Approach to Visualizing Homicide Rates and Other Georeferenced Statistical Data

Science.gov (United States)

Mazzitello, Karina I.; Candia, Julián

2012-12-01

In every country, public and private agencies allocate extensive funding to collect large-scale statistical data, which in turn are studied and analyzed in order to determine local, regional, national, and international policies regarding all aspects relevant to the welfare of society. One important aspect of that process is the visualization of statistical data with embedded geographical information, which most often relies on archaic methods such as maps colored according to graded scales. In this work, we apply nonstandard visualization techniques based on physical principles. We illustrate the method with recent statistics on homicide rates in Brazil and their correlation to other publicly available data. This physics-based approach provides a novel tool that can be used by interdisciplinary teams investigating statistics and model projections in a variety of fields such as economics and gross domestic product research, public health and epidemiology, sociodemographics, political science, business and marketing, and many others.

Edge maps: Representing flow with bounded error

KAUST Repository

Bhatia, Harsh

2011-03-01

Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Many analysis techniques rely on computing streamlines, a task often hampered by numerical instabilities. Approaches that ignore the resulting errors can lead to inconsistencies that may produce unreliable visualizations and ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with linear maps defined on its boundary. This representation, called edge maps, is equivalent to computing all possible streamlines at a user defined error threshold. In spite of this error, all the streamlines computed using edge maps will be pairwise disjoint. Furthermore, our representation stores the error explicitly, and thus can be used to produce more informative visualizations. Given a piecewise-linear interpolated vector field, a recent result [15] shows that there are only 23 possible map classes for a triangle, permitting a concise description of flow behaviors. This work describes the details of computing edge maps, provides techniques to quantify and refine edge map error, and gives qualitative and visual comparisons to more traditional techniques. © 2011 IEEE.

Semantics by analogy for illustrative volume visualization

NARCIS (Netherlands)

Gerl, Moritz; Rautek, Peter; Isenberg, Tobias; Groeller, Eduard

We present an interactive graphical approach for the explicit specification of semantics for volume visualization. This explicit and graphical specification of semantics for volumetric features allows us to visually assign meaning to both input and output parameters of the visualization mapping.

Iapetus: First data from the Cassini Visual Infrared Mapping Spectrometer

Science.gov (United States)

Buratti, B. J.; Cruikshank, D. P.; Clark, R.; Brown, R. H.; Bauer, J. M.; Simonelli, D. P.; Jaumann, R.; Hibbitts, K.; McCord, T. B.; Soderlund, K.; Baines, K. H.; Bellucci, G.; Bibring, J. P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Drossart, P.; Formisano, V.; Langevin, Y.; Matson, D. L.; Mennella, V.; Nelson, R.; Nicholson, P. D.; Sicardy, B.; Sotin, C.

2004-11-01

Iapetus is perhaps the most enigmatic body in the solar system: One hemisphere is as dark as lampblack, and the other is almost as bright as snow. The models that have been offered to explain this dichotomy range from endogenously placed material (Smith et al., 1982, Science 215, 504), to material exogenously placed from Phoebe (Soter, 1974, IAU Colloq. 28), or other bodies (Owen et al., 2001, Icarus 149, 160; Buratti et al., 2002, Icarus 155, 375; Buratti et al., 2003, B.A.A.S, 915). No mechanism for the darkening process or purported source for the exogenic particles is entirely satisfactory. One key question is whether the process that led to the formation of the low-albedo hemisphere of Iapetus is unique, or whether the satellite has been subjected to a satellite alteration process in a more extreme form. Both Callisto and the outer satellites of Uranus show evidence for exogenic accretion of particles onto their leading sides. A targeted flyby of Iapetus by Cassini, during which the spacecraft will approach the satellite to within 1000 km, is scheduled to occur in September 2007. An untargeted approach of 65,000 km to the satellite will occur on New Year's day 2005, and observations are planned for the period around closest approach. However, a "sneak peak" of the satellite was afforded by Cassini on July 19, 2004, during which the spacecraft approached to less than three million miles (the Voyager closest approach was 909,070 km). The first disk resolved spectra of Iapetus in the 0.4 to 5 micron region were obtained by the Cassini Visual Infrared Mapping Spectrometer (VIMS). We report the tentative identification of carbon dioxide on the low-albedo portion of the surface. A comparison of the spectrum of Iapetus to that obtained by VIMS during its flyby of Phoebe on June 11, 2004 will be made. Mixing models incorporating water ice, minerals, and organics can replicate the spectrum of the dark hemisphere. Work performed at the Jet Propulsion Laboratory

Visual quality analysis of femtosecond LASIK and iris location guided mechanical SBK for high myopia

Directory of Open Access Journals (Sweden)

Hong-Su Jiang

2015-07-01

Full Text Available AIM: To make a analysis of visual quality of iris location guided femtosecond laser assisted in situ keratomi(LASIKand iris location guided mechanical sub-bowman keratomileusis(SBKfor high myopia treatment. METHODS:Femtosecond LASIK(study groupwas performed in 102 eyes of 51 patients with high myopia and 70 eyes of 35 patients were received mechanical SBK(control groupfrom January to October 2013. The spherical refraction of all the patients was from -6.00～-9.50D. Best corrected visual acuity(BCVAof the patients was ≥1.0. Uncorrected visual acuity(UCVA, BCVA, thickness of cornea flap, contrast sensitivity function(CSFand senior ocular aberration were examined in these patients and follow-up was 1a. RESULTS: At 1a after surgery 94.1% UCVA in study group reached ≥1.0 and there was 94.3% in control group. There was no significant difference between two groups(P>0.05. Residual refraction of study group was -0.08±0.10 D and control group was -0.10±0.07 D. There was no significant difference of residual refraction between two groups(P>0.05. C12, C8 of senior ocular aberration and RMSH in study group was less than control group, amplification: 0.1642±0.0519 and 0.2229±0.0382(t=8.077, Pt=0.556, P>0.05. C8 was 0.0950±0.069 and 0.1858±0.095(t=7.261, Pt=12.801, PP>0.05.CONCLUSION: Femtosecond LASIK and mechanical SBK is effective for high myopia. Compared to mechanical SBK, femtosecond LASIK shows more advantages in the senior ocular aberration and visual quality. The cornea flap is more regular from central to peripheral area with femtosecond laser.

Mapping visual stimuli to perceptual decisions via sparse decoding of mesoscopic neural activity.

Science.gov (United States)

Sajda, Paul

2010-01-01

In this talk I will describe our work investigating sparse decoding of neural activity, given a realistic mapping of the visual scene to neuronal spike trains generated by a model of primary visual cortex (V1). We use a linear decoder which imposes sparsity via an L1 norm. The decoder can be viewed as a decoding neuron (linear summation followed by a sigmoidal nonlinearity) in which there are relatively few non-zero synaptic weights. We find: (1) the best decoding performance is for a representation that is sparse in both space and time, (2) decoding of a temporal code results in better performance than a rate code and is also a better fit to the psychophysical data, (3) the number of neurons required for decoding increases monotonically as signal-to-noise in the stimulus decreases, with as little as 1% of the neurons required for decoding at the highest signal-to-noise levels, and (4) sparse decoding results in a more accurate decoding of the stimulus and is a better fit to psychophysical performance than a distributed decoding, for example one imposed by an L2 norm. We conclude that sparse coding is well-justified from a decoding perspective in that it results in a minimum number of neurons and maximum accuracy when sparse representations can be decoded from the neural dynamics.

Applying the metro map to software development management

Science.gov (United States)

Aguirregoitia, Amaia; Dolado, J. Javier; Presedo, Concepción

2010-01-01

This paper presents MetroMap, a new graphical representation model for controlling and managing the software development process. Metromap uses metaphors and visual representation techniques to explore several key indicators in order to support problem detection and resolution. The resulting visualization addresses diverse management tasks, such as tracking of deviations from the plan, analysis of patterns of failure detection and correction, overall assessment of change management policies, and estimation of product quality. The proposed visualization uses a metaphor with a metro map along with various interactive techniques to represent information concerning the software development process and to deal efficiently with multivariate visual queries. Finally, the paper shows the implementation of the tool in JavaFX with data of a real project and the results of testing the tool with the aforementioned data and users attempting several information retrieval tasks. The conclusion shows the results of analyzing user response time and efficiency using the MetroMap visualization system. The utility of the tool was positively evaluated.

Neural mechanisms underlying temporal modulation of visual perception

NARCIS (Netherlands)

Jong, M.C. de

2015-01-01

However confident we feel about the way we perceive the visual world around us, there is not a one-to-one relation between visual stimulation and visual perception. Our eyes register reflections of the visual environment and our brain has the difficult task of constructing ‘reality’ from this

Visual Saliency Models for Text Detection in Real World.

Directory of Open Access Journals (Sweden)

Renwu Gao

Full Text Available This paper evaluates the degree of saliency of texts in natural scenes using visual saliency models. A large scale scene image database with pixel level ground truth is created for this purpose. Using this scene image database and five state-of-the-art models, visual saliency maps that represent the degree of saliency of the objects are calculated. The receiver operating characteristic curve is employed in order to evaluate the saliency of scene texts, which is calculated by visual saliency models. A visualization of the distribution of scene texts and non-texts in the space constructed by three kinds of saliency maps, which are calculated using Itti's visual saliency model with intensity, color and orientation features, is given. This visualization of distribution indicates that text characters are more salient than their non-text neighbors, and can be captured from the background. Therefore, scene texts can be extracted from the scene images. With this in mind, a new visual saliency architecture, named hierarchical visual saliency model, is proposed. Hierarchical visual saliency model is based on Itti's model and consists of two stages. In the first stage, Itti's model is used to calculate the saliency map, and Otsu's global thresholding algorithm is applied to extract the salient region that we are interested in. In the second stage, Itti's model is applied to the salient region to calculate the final saliency map. An experimental evaluation demonstrates that the proposed model outperforms Itti's model in terms of captured scene texts.

Cardiac-driven Pulsatile Motion of Intracranial Cerebrospinal Fluid Visualized Based on a Correlation Mapping Technique.

Science.gov (United States)

Yatsushiro, Satoshi; Sunohara, Saeko; Hayashi, Naokazu; Hirayama, Akihiro; Matsumae, Mitsunori; Atsumi, Hideki; Kuroda, Kagayaki

2018-04-10

A correlation mapping technique delineating delay time and maximum correlation for characterizing pulsatile cerebrospinal fluid (CSF) propagation was proposed. After proofing its technical concept, this technique was applied to healthy volunteers and idiopathic normal pressure hydrocephalus (iNPH) patients. A time-resolved three dimensional-phase contrast (3D-PC) sampled the cardiac-driven CSF velocity at 32 temporal points per cardiac period at each spatial location using retrospective cardiac gating. The proposed technique visualized distributions of propagation delay and correlation coefficient of the PC-based CSF velocity waveform with reference to a waveform at a particular point in the CSF space. The delay time was obtained as the amount of time-shift, giving the maximum correlation for the velocity waveform at an arbitrary location with that at the reference location. The validity and accuracy of the technique were confirmed in a flow phantom equipped with a cardiovascular pump. The technique was then applied to evaluate the intracranial CSF motions in young, healthy (N = 13), and elderly, healthy (N = 13) volunteers and iNPH patients (N = 13). The phantom study demonstrated that root mean square error of the delay time was 2.27%, which was less than the temporal resolution of PC measurement used in this study (3.13% of a cardiac cycle). The human studies showed a significant difference (P correlation coefficient between the young, healthy group and the other two groups. A significant difference (P correlation coefficients in intracranial CSF space among all groups. The result suggests that the CSF space compliance of iNPH patients was lower than that of healthy volunteers. The correlation mapping technique allowed us to visualize pulsatile CSF velocity wave propagations as still images. The technique may help to classify diseases related to CSF dynamics, such as iNPH.

The visual attention span deficit in dyslexia is visual and not verbal.

Science.gov (United States)

Lobier, Muriel; Zoubrinetzky, Rachel; Valdois, Sylviane

2012-06-01

The visual attention (VA) span deficit hypothesis of dyslexia posits that letter string deficits are a consequence of impaired visual processing. Alternatively, some have interpreted this deficit as resulting from a visual-to-phonology code mapping impairment. This study aims to disambiguate between the two interpretations by investigating performance in a non-verbal character string visual categorization task with verbal and non-verbal stimuli. Results show that VA span ability predicts performance for the non-verbal visual processing task in normal reading children. Furthermore, VA span impaired dyslexic children are also impaired for the categorization task independently of stimuli type. This supports the hypothesis that the underlying impairment responsible for the VA span deficit is visual, not verbal. Copyright © 2011 Elsevier Srl. All rights reserved.

Extracting Semantic Information from Visual Data: A Survey

Directory of Open Access Journals (Sweden)

Qiang Liu

2016-03-01

Full Text Available The traditional environment maps built by mobile robots include both metric ones and topological ones. These maps are navigation-oriented and not adequate for service robots to interact with or serve human users who normally rely on the conceptual knowledge or semantic contents of the environment. Therefore, the construction of semantic maps becomes necessary for building an effective human-robot interface for service robots. This paper reviews recent research and development in the field of visual-based semantic mapping. The main focus is placed on how to extract semantic information from visual data in terms of feature extraction, object/place recognition and semantic representation methods.

Visualizing the nuclear science and technology knowledge domain

Energy Technology Data Exchange (ETDEWEB)

Melo, Bruno Mattos Souza de Souza; Honaiser, Eduardo H.R. [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil)]. E-mails: brunomelo@ieee.org; ehonaiser@yahoo.com.br

2007-07-01

In this paper, a knowledge domain visualization approach is applied to the nuclear science and technology fields. A so-called concept density map based on the abstracts of the papers presented at the ICONE 14 is constructed. The concept map provides an overview of the nuclear science and technology fields by visualizing the associations between their main concepts. To analyze recent developments the concept map is compared with a concept map based on abstracts of earlier ICONE meetings. The analysis presented in the paper provides insight into the structure of the nuclear science and technology fields and into the most significant developments carried out during the last few years. (author)

A Visual Analytics Approach for Station-Based Air Quality Data

Directory of Open Access Journals (Sweden)

Yi Du

2016-12-01

Full Text Available With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.

A Visual Analytics Approach for Station-Based Air Quality Data.

Science.gov (United States)

Du, Yi; Ma, Cuixia; Wu, Chao; Xu, Xiaowei; Guo, Yike; Zhou, Yuanchun; Li, Jianhui

2016-12-24

With the deployment of multi-modality and large-scale sensor networks for monitoring air quality, we are now able to collect large and multi-dimensional spatio-temporal datasets. For these sensed data, we present a comprehensive visual analysis approach for air quality analysis. This approach integrates several visual methods, such as map-based views, calendar views, and trends views, to assist the analysis. Among those visual methods, map-based visual methods are used to display the locations of interest, and the calendar and the trends views are used to discover the linear and periodical patterns. The system also provides various interaction tools to combine the map-based visualization, trends view, calendar view and multi-dimensional view. In addition, we propose a self-adaptive calendar-based controller that can flexibly adapt the changes of data size and granularity in trends view. Such a visual analytics system would facilitate big-data analysis in real applications, especially for decision making support.

A novel continuous colour mapping approach for visualization of facial skin hydration and transepidermal water loss for four ethnic groups.

Science.gov (United States)

Voegeli, R; Rawlings, A V; Seroul, P; Summers, B

2015-12-01

The aim of this exploratory study was to develop a novel colour mapping approach to visualize and interpret the complexity of facial skin hydration and barrier properties of four ethnic groups (Caucasians, Indians, Chinese and Black Africans) living in Pretoria, South Africa. We measured transepidermal water loss (TEWL) and skin capacitance on 30 pre-defined sites on the forehead, cheek, jaw and eye areas of sixteen women (four per ethnic group) and took digital images of their faces. Continuous colour maps were generated by interpolating between each measured value and superimposing the values on the digital images. The complexity of facial skin hydration and skin barrier properties is revealed by these measurements and visualized by the continuous colour maps of the digital images. Overall, the Caucasian subjects had the better barrier properties followed by the Black African subjects, Chinese subjects and Indian subjects. Nevertheless, the two more darkly pigmented ethnic groups had superior skin hydration properties. Subtle differences were seen when examining the different facial sites. There exists remarkable skin capacitance and TEWL gradients within short distances on selected areas of the face. These gradients are distinctive in the different ethnic groups. In contrast to other reports, we found that darkly pigmented skin does not always have a superior barrier function and differences in skin hydration values are complex on the different parts of the face among the different ethnic groups. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Aging of non-visual spectral sensitivity to light in humans: compensatory mechanisms?

Directory of Open Access Journals (Sweden)

Raymond P Najjar

Full Text Available The deterioration of sleep in the older population is a prevalent feature that contributes to a decrease in quality of life. Inappropriate entrainment of the circadian clock by light is considered to contribute to the alteration of sleep structure and circadian rhythms in the elderly. The present study investigates the effects of aging on non-visual spectral sensitivity to light and tests the hypothesis that circadian disturbances are related to a decreased light transmittance. In a within-subject design, eight aged and five young subjects were exposed at night to 60 minute monochromatic light stimulations at 9 different wavelengths (420-620 nm. Individual sensitivity spectra were derived from measures of melatonin suppression. Lens density was assessed using a validated psychophysical technique. Although lens transmittance was decreased for short wavelength light in the older participants, melatonin suppression was not reduced. Peak of non-visual sensitivity was, however, shifted to longer wavelengths in the aged participants (494 nm compared to young (484 nm. Our results indicate that increased lens filtering does not necessarily lead to a decreased non-visual sensitivity to light. The lack of age-related decrease in non-visual sensitivity to light may involve as yet undefined adaptive mechanisms.

Immune mapping of the peripheral part of the visual analyzer and optic nerve

Directory of Open Access Journals (Sweden)

V. G. Likhvantseva

2014-10-01

Full Text Available Aim. To perform immune mapping of the peripheral part of visual analyzer and optic nerve in order to identify potential antigenic targets of autoimmune attack. Methods. Eyes enucleated for terminal painful glaucoma (n = 30 were studied. Immunohistochemistry (IHC was performed on paraffin-embedded sections of isolated retina and optic nerve using a broad panel of antibodies, i.e., monoclonal murine anti-MBP (myelin basic protein antibodies, polyclonal rabbit anti-alpha fodrin antibodies, monoclonal murine anti-NSE2 (neuron-specific enolase antibodies, monoclonal murine anti-GFAP (glial fibrillary acidic protein, and polyclonal rabbit anti-S100 antibodies. IHC reaction was visualized using Mouse and Rabbit Specific HRP / AEC Detection IHC Kit. IHC reaction without primary antibodies included was a negative control. IHC reaction was considered as follows: negative — no specific cellular staining or less than 10 % of cells are stained; mild — 10‑30 % of cells are stained (+; moderate — 30‑75 % of cells are stained (++; marked — more than 75 % of cells are stained (+++; overexpression — 100 % of cells intensively express markers. Additionally, staining intensity was considered as mild (+1, moderate (+2, strong (+3 and intense (+4.Results. Immune mapping with a broad panel of monoclonal antibodies identified ocular structures which were stained with IHC markers. Retina was stained with almost all markers of neural differentiation (i.e., antibodies against NSE, GFAP, S100, and α-fodrin excepting anti-MBP autoantibodies. IHC reaction intensity in retinal layers and structures varied and depended on markers. Moderate (2+ staining with antibodies against MBP, NSE, GFAP, and S100 and marked (3+ staining with antibodies against alpha-fodrin was detected in the cytoplasm of optic nerve glia.Conclusion. Complete labelling of retina structures was performed. As a result, IHC profiles of retinal neurons, optic nerve axons

Immune mapping of the peripheral part of the visual analyzer and optic nerve

Directory of Open Access Journals (Sweden)

V. G. Likhvantseva

2014-01-01

Full Text Available Aim. To perform immune mapping of the peripheral part of visual analyzer and optic nerve in order to identify potential antigenic targets of autoimmune attack. Methods. Eyes enucleated for terminal painful glaucoma (n = 30 were studied. Immunohistochemistry (IHC was performed on paraffin-embedded sections of isolated retina and optic nerve using a broad panel of antibodies, i.e., monoclonal murine anti-MBP (myelin basic protein antibodies, polyclonal rabbit anti-alpha fodrin antibodies, monoclonal murine anti-NSE2 (neuron-specific enolase antibodies, monoclonal murine anti-GFAP (glial fibrillary acidic protein, and polyclonal rabbit anti-S100 antibodies. IHC reaction was visualized using Mouse and Rabbit Specific HRP / AEC Detection IHC Kit. IHC reaction without primary antibodies included was a negative control. IHC reaction was considered as follows: negative — no specific cellular staining or less than 10 % of cells are stained; mild — 10‑30 % of cells are stained (+; moderate — 30‑75 % of cells are stained (++; marked — more than 75 % of cells are stained (+++; overexpression — 100 % of cells intensively express markers. Additionally, staining intensity was considered as mild (+1, moderate (+2, strong (+3 and intense (+4.Results. Immune mapping with a broad panel of monoclonal antibodies identified ocular structures which were stained with IHC markers. Retina was stained with almost all markers of neural differentiation (i.e., antibodies against NSE, GFAP, S100, and α-fodrin excepting anti-MBP autoantibodies. IHC reaction intensity in retinal layers and structures varied and depended on markers. Moderate (2+ staining with antibodies against MBP, NSE, GFAP, and S100 and marked (3+ staining with antibodies against alpha-fodrin was detected in the cytoplasm of optic nerve glia.Conclusion. Complete labelling of retina structures was performed. As a result, IHC profiles of retinal neurons, optic nerve axons

How Scientists Develop Competence in Visual Communication

Science.gov (United States)

Ostergren, Marilyn

2013-01-01

Visuals (maps, charts, diagrams and illustrations) are an important tool for communication in most scientific disciplines, which means that scientists benefit from having strong visual communication skills. This dissertation examines the nature of competence in visual communication and the means by which scientists acquire this competence. This…

ComVisMD - compact visualization of multidimensional data: experimenting with cricket players data

Science.gov (United States)

Dandin, Shridhar B.; Ducassé, Mireille

2018-03-01

Database information is multidimensional and often displayed in tabular format (row/column display). Presented in aggregated form, multidimensional data can be used to analyze the records or objects. Online Analytical database Processing (OLAP) proposes mechanisms to display multidimensional data in aggregated forms. A choropleth map is a thematic map in which areas are colored in proportion to the measurement of a statistical variable being displayed, such as population density. They are used mostly for compact graphical representation of geographical information. We propose a system, ComVisMD inspired by choropleth map and the OLAP cube to visualize multidimensional data in a compact way. ComVisMD displays multidimensional data like OLAP Cube, where we are mapping an attribute a (first dimension, e.g. year started playing cricket) in vertical direction, object coloring based on b (second dimension, e.g. batting average), mapping varying-size circles based on attribute c (third dimension, e.g. highest score), mapping numbers based on attribute d (fourth dimension, e.g. matches played). We illustrate our approach on cricket players data, namely on two tables Country and Player. They have a large number of rows and columns: 246 rows and 17 columns for players of one country. ComVisMD’s visualization reduces the size of the tabular display by a factor of about 4, allowing users to grasp more information at a time than the bare table display.

Synchronized 2D/3D optical mapping for interactive exploration and real-time visualization of multi-function neurological images.

Science.gov (United States)

Zhang, Qi; Alexander, Murray; Ryner, Lawrence

2013-01-01

Efficient software with the ability to display multiple neurological image datasets simultaneously with full real-time interactivity is critical for brain disease diagnosis and image-guided planning. In this paper, we describe the creation and function of a new comprehensive software platform that integrates novel algorithms and functions for multiple medical image visualization, processing, and manipulation. We implement an opacity-adjustment algorithm to build 2D lookup tables for multiple slice image display and fusion, which achieves a better visual result than those of using VTK-based methods. We also develop a new real-time 2D and 3D data synchronization scheme for multi-function MR volume and slice image optical mapping and rendering simultaneously through using the same adjustment operation. All these methodologies are integrated into our software framework to provide users with an efficient tool for flexibly, intuitively, and rapidly exploring and analyzing the functional and anatomical MR neurological data. Finally, we validate our new techniques and software platform with visual analysis and task-specific user studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Playing the electric light orchestra--how electrical stimulation of visual cortex elucidates the neural basis of perception.

Science.gov (United States)

Cicmil, Nela; Krug, Kristine

2015-09-19

Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the 'causal map' of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making.

A Visual Framework for Digital Reconstruction of Topographic Maps

KAUST Repository

Thabet, Ali Kassem

2014-09-30

We present a framework for reconstructing Digital Elevation Maps (DEM) from scanned topographic maps. We first rectify the images to ensure that maps fit together without distortion. To segment iso-contours, we have developed a novel semi-automated method based on mean-shifts that requires only minimal user interaction. Contour labels are automatically read using an OCR module. To reconstruct the output DEM from scattered data, we generalize natural neighbor interpolation to handle the transfinite case (contours and points). To this end, we use parallel vector propagation to compute a discrete Voronoi diagram of the constraints, and a modified floodfill to compute virtual Voronoi tiles. Our framework is able to handle tens of thousands of contours and points and can generate DEMs comprising more than 100 million samples. We provide quantitative comparison to commercial software and show the benefits of our approach. We furthermore show the robustness of our method on a massive set of old maps predating satellite acquisition. Compared to other methods, our framework is able to accurately and efficiently generate a final DEM despite inconsistencies, sparse or missing contours even for highly complex and cluttered maps. Therefore, this method has broad applicability for digitization and reconstruction of the world\\'s old topographic maps that are often the only record of past landscapess and cultural heritage before their destruction under modern development.

Correlated individual differences suggest a common mechanism underlying metacognition in visual perception and visual short-term memory.

Science.gov (United States)

Samaha, Jason; Postle, Bradley R

2017-11-29

Adaptive behaviour depends on the ability to introspect accurately about one's own performance. Whether this metacognitive ability is supported by the same mechanisms across different tasks is unclear. We investigated the relationship between metacognition of visual perception and metacognition of visual short-term memory (VSTM). Experiments 1 and 2 required subjects to estimate the perceived or remembered orientation of a grating stimulus and rate their confidence. We observed strong positive correlations between individual differences in metacognitive accuracy between the two tasks. This relationship was not accounted for by individual differences in task performance or average confidence, and was present across two different metrics of metacognition and in both experiments. A model-based analysis of data from a third experiment showed that a cross-domain correlation only emerged when both tasks shared the same task-relevant stimulus feature. That is, metacognition for perception and VSTM were correlated when both tasks required orientation judgements, but not when the perceptual task was switched to require contrast judgements. In contrast with previous results comparing perception and long-term memory, which have largely provided evidence for domain-specific metacognitive processes, the current findings suggest that metacognition of visual perception and VSTM is supported by a domain-general metacognitive architecture, but only when both domains share the same task-relevant stimulus feature. © 2017 The Author(s).

Expressive map design: OGC SLD/SE++ extension for expressive map styles

Science.gov (United States)

Christophe, Sidonie; Duménieu, Bertrand; Masse, Antoine; Hoarau, Charlotte; Ory, Jérémie; Brédif, Mathieu; Lecordix, François; Mellado, Nicolas; Turbet, Jérémie; Loi, Hugo; Hurtut, Thomas; Vanderhaeghe, David; Vergne, Romain; Thollot, Joëlle

2018-05-01

In the context of custom map design, handling more artistic and expressive tools has been identified as a carto-graphic need, in order to design stylized and expressive maps. Based on previous works on style formalization, an approach for specifying the map style has been proposed and experimented for particular use cases. A first step deals with the analysis of inspiration sources, in order to extract `what does make the style of the source', i.e. the salient visual characteristics to be automatically reproduced (textures, spatial arrangements, linear stylization, etc.). In a second step, in order to mimic and generate those visual characteristics, existing and innovative rendering techniques have been implemented in our GIS engine, thus extending the capabilities to generate expressive renderings. Therefore, an extension of the existing cartographic pipeline has been proposed based on the following aspects: 1- extension of the symbolization specifications OGC SLD/SE in order to provide a formalism to specify and reference expressive rendering methods; 2- separate the specification of each rendering method and its parameterization, as metadata. The main contribution has been described in (Christophe et al. 2016). In this paper, we focus firstly on the extension of the cartographic pipeline (SLD++ and metadata) and secondly on map design capabilities which have been experimented on various topographic styles: old cartographic styles (Cassini), artistic styles (watercolor, impressionism, Japanese print), hybrid topographic styles (ortho-imagery & vector data) and finally abstract and photo-realist styles for the geovisualization of costal area. The genericity and interoperability of our approach are promising and have already been tested for 3D visualization.

Visual attention

NARCIS (Netherlands)

Evans, K.K.; Horowitz, T.S.; Howe, P.; Pedersini, R.; Reijnen, E.; Pinto, Y.; Wolfe, J.M.

2011-01-01

A typical visual scene we encounter in everyday life is complex and filled with a huge amount of perceptual information. The term, ‘visual attention’ describes a set of mechanisms that limit some processing to a subset of incoming stimuli. Attentional mechanisms shape what we see and what we can act

Improving Visual Communication.

Science.gov (United States)

Singh, Gary

2018-01-01

A tool that creates realtime interactive color maps for scientific visualization helped enhance the dynamics of a major research project for the Climate, Ocean, and Sea Ice Modeling team at Los Alamos National Laboratory.

Visual Meta-Programming Notation

National Research Council Canada - National Science Library

Auguston, Mikhail

2001-01-01

...), encapsulation means for hierarchical rules design, two-dimensional data-flow diagrams for rules, visual control constructs for conditionals and iteration, default mapping results to reduce real...

COMPARING IMAGE-BASED METHODS FOR ASSESSING VISUAL CLUTTER IN GENERALIZED MAPS

Directory of Open Access Journals (Sweden)

G. Touya

2015-08-01

Full Text Available Map generalization abstracts and simplifies geographic information to derive maps at smaller scales. The automation of map generalization requires techniques to evaluate the global quality of a generalized map. The quality and legibility of a generalized map is related to the complexity of the map, or the amount of clutter in the map, i.e. the excessive amount of information and its disorganization. Computer vision research is highly interested in measuring clutter in images, and this paper proposes to compare some of the existing techniques from computer vision, applied to generalized maps evaluation. Four techniques from the literature are described and tested on a large set of maps, generalized at different scales: edge density, subband entropy, quad tree complexity, and segmentation clutter. The results are analyzed against several criteria related to generalized maps, the identification of cluttered areas, the preservation of the global amount of information, the handling of occlusions and overlaps, foreground vs background, and blank space reduction.

Differences in Spatial Knowledge of Individuals with Blindness When Using Audiotactile Maps, Using Tactile Maps, and Walking

Science.gov (United States)

Papadopoulos, Konstantinos; Barouti, Marialena; Koustriava, Eleni

2018-01-01

To examine how individuals with visual impairments understand space and the way they develop cognitive maps, we studied the differences in cognitive maps resulting from different methods and tools for spatial coding in large geographical spaces. We examined the ability of 21 blind individuals to create cognitive maps of routes in unfamiliar areas…

USGS NAIP Imagery Overlay Map Service from The National Map

Data.gov (United States)

U.S. Geological Survey, Department of the Interior — The USGS NAIP Imagery service from The National Map (TNM) consists of high resolution images that combine the visual attributes of an aerial photograph with the...

EEG Topographic Mapping of Visual and Kinesthetic Imagery in Swimmers.

Science.gov (United States)

Wilson, V E; Dikman, Z; Bird, E I; Williams, J M; Harmison, R; Shaw-Thornton, L; Schwartz, G E

2016-03-01

This study investigated differences in QEEG measures between kinesthetic and visual imagery of a 100-m swim in 36 elite competitive swimmers. Background information and post-trial checks controlled for the modality of imagery, swimming skill level, preferred imagery style, intensity of image and task equality. Measures of EEG relative magnitude in theta, low (7-9 Hz) and high alpha (8-10 Hz), and low and high beta were taken from 19 scalp sites during baseline, visual, and kinesthetic imagery. QEEG magnitudes in the low alpha band during the visual and kinesthetic conditions were attenuated from baseline in low band alpha but no changes were seen in any other bands. Swimmers produced more low alpha EEG magnitude during visual versus kinesthetic imagery. This was interpreted as the swimmers having a greater efficiency at producing visual imagery. Participants who reported a strong intensity versus a weaker feeling of the image (kinesthetic) had less low alpha magnitude, i.e., there was use of more cortical resources, but not for the visual condition. These data suggest that low band (7-9 Hz) alpha distinguishes imagery modalities from baseline, visual imagery requires less cortical resources than kinesthetic imagery, and that intense feelings of swimming requires more brain activity than less intense feelings.

The spatiotopic 'visual' cortex of the blind

Science.gov (United States)

Likova, Lora

2012-03-01

Visual cortex activity in the blind has been shown in sensory tasks. Can it be activated in memory tasks? If so, are inherent features of its organization meaningfully employed? Our recent results in short-term blindfolded subjects imply that human primary visual cortex (V1) may operate as a modality-independent 'sketchpad' for working memory (Likova, 2010a). Interestingly, the spread of the V1 activation approximately corresponded to the spatial extent of the images in terms of their angle of projection to the subject. We now raise the questions of whether under long-term visual deprivation V1 is also employed in non-visual memory task, in particular in congenitally blind individuals, who have never had visual stimulation to guide the development of the visual area organization, and whether such spatial organization is still valid for the same paradigm that was used in blindfolded individuals. The outcome has implications for an emerging reconceptualization of the principles of brain architecture and its reorganization under sensory deprivation. Methods: We used a novel fMRI drawing paradigm in congenitally and late-onset blind, compared with sighted and blindfolded subjects in three conditions of 20s duration, separated by 20s rest-intervals, (i) Tactile Exploration: raised-line images explored and memorized; (ii) Tactile Memory Drawing: drawing the explored image from memory; (iii) Scribble: mindless drawing movements with no memory component. Results and Conclusions: V1 was strongly activated for Tactile Memory Drawing and Tactile Exploration in these totally blind subjects. Remarkably, after training, even in the memory task, the mapping of V1 activation largely corresponded to the angular projection of the tactile stimuli relative to the ego-center (i.e., the effective visual angle at the head); beyond this projective boundary, peripheral V1 signals were dramatically reduced or even suppressed. The matching extent of the activation in the congenitally blind

Mapping and Visualization of Storm-Surge Dynamics for Hurricane Katrina and Hurricane Rita

Science.gov (United States)

Gesch, Dean B.

2009-01-01

The damages caused by the storm surges from Hurricane Katrina and Hurricane Rita were significant and occurred over broad areas. Storm-surge maps are among the most useful geospatial datasets for hurricane recovery, impact assessments, and mitigation planning for future storms. Surveyed high-water marks were used to generate a maximum storm-surge surface for Hurricane Katrina extending from eastern Louisiana to Mobile Bay, Alabama. The interpolated surface was intersected with high-resolution lidar elevation data covering the study area to produce a highly detailed digital storm-surge inundation map. The storm-surge dataset and related data are available for display and query in a Web-based viewer application. A unique water-level dataset from a network of portable pressure sensors deployed in the days just prior to Hurricane Rita's landfall captured the hurricane's storm surge. The recorded sensor data provided water-level measurements with a very high temporal resolution at surveyed point locations. The resulting dataset was used to generate a time series of storm-surge surfaces that documents the surge dynamics in a new, spatially explicit way. The temporal information contained in the multiple storm-surge surfaces can be visualized in a number of ways to portray how the surge interacted with and was affected by land surface features. Spatially explicit storm-surge products can be useful for a variety of hurricane impact assessments, especially studies of wetland and land changes where knowledge of the extent and magnitude of storm-surge flooding is critical.

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

Science.gov (United States)

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

2011-04-01

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 of the study consisted of six classes (140 Form 3 students of 13-15 years old) selected from a typical coeducational school in Brunei. Three classes (40 boys and 30 girls) were taught using the TTA while three other classes (41 boys and 29 girls) used the CMA, enriched with PowerPoint presentations. After the interventions (lessons on magnetism), the students in both groups were asked to describe in writing their understanding of magnetism accrued from the lessons. Their written descriptions were analyzed using flow map analyses to assess their content knowledge and its organisation in memory as evidence of cognitive structure. The extent of CLE was measured using a published CLE survey. The results showed that the cognitive structures of the CMA students were more extensive, thematically organised and richer in interconnectedness of thoughts than those of TTA students. Moreover, CMA students also perceived their classroom learning environment to be more constructivist than their counterparts. It is, therefore, recommended that teachers consider using the CMA teaching technique to help students enrich their understanding, especially for more complex or abstract scientific content.

MPEG-4 AVC saliency map computation

Science.gov (United States)

Ammar, M.; Mitrea, M.; Hasnaoui, M.

2014-02-01

A saliency map provides information about the regions inside some visual content (image, video, ...) at which a human observer will spontaneously look at. For saliency maps computation, current research studies consider the uncompressed (pixel) representation of the visual content and extract various types of information (intensity, color, orientation, motion energy) which are then fusioned. This paper goes one step further and computes the saliency map directly from the MPEG-4 AVC stream syntax elements with minimal decoding operations. In this respect, an a-priori in-depth study on the MPEG-4 AVC syntax elements is first carried out so as to identify the entities appealing the visual attention. Secondly, the MPEG-4 AVC reference software is completed with software tools allowing the parsing of these elements and their subsequent usage in objective benchmarking experiments. This way, it is demonstrated that an MPEG-4 saliency map can be given by a combination of static saliency and motion maps. This saliency map is experimentally validated under a robust watermarking framework. When included in an m-QIM (multiple symbols Quantization Index Modulation) insertion method, PSNR average gains of 2.43 dB, 2.15dB, and 2.37 dB are obtained for data payload of 10, 20 and 30 watermarked blocks per I frame, i.e. about 30, 60, and 90 bits/second, respectively. These quantitative results are obtained out of processing 2 hours of heterogeneous video content.

Effect of mechanical tactile noise on amplitude of visual evoked potentials: multisensory stochastic resonance.

Science.gov (United States)

Méndez-Balbuena, Ignacio; Huidobro, Nayeli; Silva, Mayte; Flores, Amira; Trenado, Carlos; Quintanar, Luis; Arias-Carrión, Oscar; Kristeva, Rumyana; Manjarrez, Elias

2015-10-01

The present investigation documents the electrophysiological occurrence of multisensory stochastic resonance in the human visual pathway elicited by tactile noise. We define multisensory stochastic resonance of brain evoked potentials as the phenomenon in which an intermediate level of input noise of one sensory modality enhances the brain evoked response of another sensory modality. Here we examined this phenomenon in visual evoked potentials (VEPs) modulated by the addition of tactile noise. Specifically, we examined whether a particular level of mechanical Gaussian noise applied to the index finger can improve the amplitude of the VEP. We compared the amplitude of the positive P100 VEP component between zero noise (ZN), optimal noise (ON), and high mechanical noise (HN). The data disclosed an inverted U-like graph for all the subjects, thus demonstrating the occurrence of a multisensory stochastic resonance in the P100 VEP. Copyright © 2015 the American Physiological Society.

A Visual Interface Diagram For Mapping Functions In Integrated Products

DEFF Research Database (Denmark)

Ingerslev, Mattias; Oliver Jespersen, Mikkel; Göhler, Simon Moritz

2015-01-01

In product development there is a recognized tendency towards increased functionality for each new product generation. This leads to more integrated and complex products, with the risk of development delays and quality issues as a consequence of lacking overview and transparency. The work described...... of visualizing relations between parts and functions in highly integrated mechanical products. The result is an interface diagram that supports design teams in communication, decision making and design management. The diagram gives the designer an overview of the couplings and dependencies within a product...... in this article has been conducted in collaboration with Novo Nordisk on the insulin injection device FlexTouch® as case product. The FlexTouch® reflects the characteristics of an integrated product with several functions shared between a relatively low number of parts. In this article we present a novel way...

A functional magnetic resonance imaging investigation of visual hallucinations in the human striate cortex.

Science.gov (United States)

Abid, Hina; Ahmad, Fayyaz; Lee, Soo Y; Park, Hyun W; Im, Dongmi; Ahmad, Iftikhar; Chaudhary, Safee U

2016-11-29

Human beings frequently experience fear, phobia, migraine and hallucinations, however, the cerebral mechanisms underpinning these conditions remain poorly understood. Towards this goal, in this work, we aim to correlate the human ocular perceptions with visual hallucinations, and map them to their cerebral origins. An fMRI study was performed to examine the visual cortical areas including the striate, parastriate and peristriate cortex in the occipital lobe of the human brain. 24 healthy subjects were enrolled and four visual patterns including hallucination circle (HCC), hallucination fan (HCF), retinotopy circle (RTC) and retinotopy cross (RTX) were used towards registering their impact in the aforementioned visual related areas. One-way analysis of variance was used to evaluate the significance of difference between induced activations. Multinomial regression and and K-means were used to cluster activation patterns in visual areas of the brain. Significant activations were observed in the visual cortex as a result of stimulus presentation. The responses induced by visual stimuli were resolved to Brodmann areas 17, 18 and 19. Activation data clustered into independent and mutually exclusive clusters with HCC registering higher activations as compared to HCF, RTC and RTX. We conclude that small circular objects, in rotation, tend to leave greater hallucinating impressions in the visual region. The similarity between observed activation patterns and those reported in conditions such as epilepsy and visual hallucinations can help elucidate the cortical mechanisms underlying these conditions. Trial Registration 1121_GWJUNG.

Different cortical mechanisms for spatial vs. feature-based attentional selection in visual working memory

Directory of Open Access Journals (Sweden)

Anna Heuer

2016-08-01

Full Text Available The limited capacity of visual working memory necessitates attentional mechanisms that selectively update and maintain only the most task-relevant content. Psychophysical experiments have shown that the retroactive selection of memory content can be based on visual properties such as location or shape, but the neural basis for such differential selection is unknown. For example, it is not known if there are different cortical modules specialized for spatial versus feature-based mnemonic attention, in the same way that has been demonstrated for attention to perceptual input. Here, we used transcranial magnetic stimulation (TMS to identify areas in human parietal and occipital cortex involved in the selection of objects from memory based on cues to their location (spatial information or their shape (featural information. We found that TMS over the supramarginal gyrus (SMG selectively facilitated spatial selection, whereas TMS over the lateral occipital cortex selectively enhanced feature-based selection for remembered objects in the contralateral visual field. Thus, different cortical regions are responsible for spatial vs. feature-based selection of working memory representations. Since the same regions are involved in attention to external events, these new findings indicate overlapping mechanisms for attentional control over perceptual input and mnemonic representations.

Human V4 and ventral occipital retinotopic maps

Science.gov (United States)

Winawer, Jonathan; Witthoft, Nathan

2016-01-01

The ventral surface of the human occipital lobe contains multiple retinotopic maps. The most posterior of these maps is considered a potential homolog of macaque V4, and referred to as human V4 (‘hV4’). The location of the hV4 map, its retinotopic organization, its role in visual encoding, and the cortical areas it borders have been the subject of considerable investigation and debate over the last 25 years. We review the history of this map and adjacent maps in ventral occipital cortex, and consider the different hypotheses for how these ventral occipital maps are organized. Advances in neuroimaging, computational modeling, and characterization of the nearby anatomical landmarks and functional brain areas have improved our understanding of where human V4 is and what kind of visual representations it contains. PMID:26241699

Data points visualization that means something

CERN Document Server

Yau, Nathan

2013-01-01

A fresh look at visualization from the author of Visualize This Whether it's statistical charts, geographic maps, or the snappy graphical statistics you see on your favorite news sites, the art of data graphics or visualization is fast becoming a movement of its own. In Data Points: Visualization That Means Something, author Nathan Yau presents an intriguing complement to his bestseller Visualize This, this time focusing on the graphics side of data analysis. Using examples from art, design, business, statistics, cartography, and online media, he explores both

Top-Down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action

Science.gov (United States)

Wang, Chao; Rajagovindan, Rajasimhan; Han, Sahng-Min; Ding, Mingzhou

2016-01-01

Alpha oscillations (8–12 Hz) are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a) identifying the signals that mediate the top-down biasing influence, (b) examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c) establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF) and the right inferior frontal gyrus (IFG) being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG) being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an inhibition

Prediction of the visual impact of motorways using GIS

International Nuclear Information System (INIS)

Jiang, Like; Kang, Jian; Schroth, Olaf

2015-01-01

Large scale transportation projects can adversely affect the visual perception of environmental quality and require adequate visual impact assessment. In this study, we investigated the effects of the characteristics of the road project and the character of the existing landscape on the perceived visual impact of motorways, and developed a GIS-based prediction model based on the findings. An online survey using computer-visualised scenes of different motorway and landscape scenarios was carried out to obtain perception-based judgements on the visual impact. Motorway scenarios simulated included the baseline scenario without road, original motorway, motorways with timber noise barriers, transparent noise barriers and tree screen; different landscape scenarios were created by changing land cover of buildings and trees in three distance zones. The landscape content of each scene was measured in GIS. The result shows that presence of a motorway especially with the timber barrier significantly decreases the visual quality of the view. The resulted visual impact tends to be lower where it is less visually pleasant with more buildings in the view, and can be slightly reduced by the visual absorption effect of the scattered trees between the motorway and the viewpoint. Based on the survey result, eleven predictors were identified for the visual impact prediction model which was applied in GIS to generate maps of visual impact of motorways in different scenarios. The proposed prediction model can be used to achieve efficient and reliable assessment of visual impact of motorways. - Highlights: • Motorways induce significant visual impact especially with timber noise barriers. • Visual impact is negatively correlated with amount of buildings in the view. • Visual impact is positively correlated with percentage of trees in the view. • Perception-based motorway visual impact prediction model using mapped predictors • Predicted visual impacts in different scenarios are

Prediction of the visual impact of motorways using GIS

Energy Technology Data Exchange (ETDEWEB)

Jiang, Like [School of Architecture, University of Sheffield, Sheffield S10 2TN (United Kingdom); Kang, Jian, E-mail: j.kang@sheffield.ac.uk [School of Architecture, University of Sheffield, Sheffield S10 2TN (United Kingdom); Schroth, Olaf [Department of Landscape, University of Sheffield, Sheffield S10 2TN (United Kingdom)

2015-11-15

Large scale transportation projects can adversely affect the visual perception of environmental quality and require adequate visual impact assessment. In this study, we investigated the effects of the characteristics of the road project and the character of the existing landscape on the perceived visual impact of motorways, and developed a GIS-based prediction model based on the findings. An online survey using computer-visualised scenes of different motorway and landscape scenarios was carried out to obtain perception-based judgements on the visual impact. Motorway scenarios simulated included the baseline scenario without road, original motorway, motorways with timber noise barriers, transparent noise barriers and tree screen; different landscape scenarios were created by changing land cover of buildings and trees in three distance zones. The landscape content of each scene was measured in GIS. The result shows that presence of a motorway especially with the timber barrier significantly decreases the visual quality of the view. The resulted visual impact tends to be lower where it is less visually pleasant with more buildings in the view, and can be slightly reduced by the visual absorption effect of the scattered trees between the motorway and the viewpoint. Based on the survey result, eleven predictors were identified for the visual impact prediction model which was applied in GIS to generate maps of visual impact of motorways in different scenarios. The proposed prediction model can be used to achieve efficient and reliable assessment of visual impact of motorways. - Highlights: • Motorways induce significant visual impact especially with timber noise barriers. • Visual impact is negatively correlated with amount of buildings in the view. • Visual impact is positively correlated with percentage of trees in the view. • Perception-based motorway visual impact prediction model using mapped predictors • Predicted visual impacts in different scenarios are

Cowichan Valley energy mapping and modelling. Report 5 - Energy density mapping projections. Final report. [Vancouver Island, Canada

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-06-15

The driving force behind the Integrated Energy Mapping and Analysis project was the identification and analysis of a suite of pathways that the Cowichan Valley Regional District (CVRD) can utilise to increase its energy resilience, as well as reduce energy consumption and GHG emissions, with a primary focus on the residential sector. Mapping and analysis undertaken will support provincial energy and GHG reduction targets, and the suite of pathways outlined will address a CVRD internal target that calls for 75% of the region's energy within the residential sector to come from locally sourced renewables by 2050. The target has been developed as a mechanism to meet resilience and climate action target. The maps and findings produced are to be integrated as part of a regional policy framework currently under development. Task 5 focused on energy projection mapping to estimate and visualise the energy consumption density and GHG emissions under different scenarios. The scenarios from task 4 were built around the energy consumption density of the residential sector under future land use patterns and rely on different energy source combinations (the suite of pathways). In task 5 the energy usage under the different scenarios were fed back into GIS, thereby giving a visual representation of forecasted residential energy consumption per unit area. The methodology is identical to that used in task 2 where current usage was mapped, whereas the mapping in this task is for future forecasts. These results are documented in this report. In addition, GHG mapping under the various scenarios was also undertaken. (LN)

The Visual System

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Full Text Available ... search for current job openings visit HHS USAJobs Home >> NEI for Kids >> The Visual System Listen All ... up to 28,800 times a day! NEI Home Contact Us A-Z Site Map NEI on ...

Spatiotopic coding of BOLD signal in human visual cortex depends on spatial attention.

Directory of Open Access Journals (Sweden)

Sofia Crespi

Full Text Available The neural substrate of the phenomenological experience of a stable visual world remains obscure. One possible mechanism would be to construct spatiotopic neural maps where the response is selective to the position of the stimulus in external space, rather than to retinal eccentricities, but evidence for these maps has been inconsistent. Here we show, with fMRI, that when human subjects perform concomitantly a demanding attentive task on stimuli displayed at the fovea, BOLD responses evoked by moving stimuli irrelevant to the task were mostly tuned in retinotopic coordinates. However, under more unconstrained conditions, where subjects could attend easily to the motion stimuli, BOLD responses were tuned not in retinal but in external coordinates (spatiotopic selectivity in many visual areas, including MT, MST, LO and V6, agreeing with our previous fMRI study. These results indicate that spatial attention may play an important role in mediating spatiotopic selectivity.

THE EVOLUTION OF CARTOGRAPHIC VISUALIZATION IN CONJUNCTION WITH GEOGRAPHIC INFORMATION SCIENCE

Directory of Open Access Journals (Sweden)

László Zentai

2014-01-01

Full Text Available The development of the digital production techniques were rapidly improved around 1980-1990 due to the requirements of information technology. Both hardware and software components were essential in the development of the technology, but the first milestone of this process was the release of personal computers. In the cartographic visualization, the GIS technologies were invented in the 1970s. However, for a very long time the development focused on the input part and on the analysis. The need for real map production features (to produce paper maps which conform to cartographic traditions in GIS software environment was raised after most of the paper maps were converted into digital ones. On the other hand, the non-GIS based map production could easily use the development of the desktop publishing technologies about ten years earlier. Nowadays the GIS-based map production offers visualization methods which do not have the antecedents in the traditional cartography. Such kinds of contemporary cartographic visualization techniques looked very trendy, but the efficiency of representation was not seriously tested. The interpretation of unusual visualization techniques can be misleading and less efficient than it was expected by the software developers. The traditional visualization techniques of thematic cartography can be successfully combined with the recent IT methods: mobile phones, tablets etc.

Necklace maps

NARCIS (Netherlands)

Speckmann, B.; Verbeek, K.A.B.

2010-01-01

Statistical data associated with geographic regions is nowadays globally available in large amounts and hence automated methods to visually display these data are in high demand. There are several well-established thematic map types for quantitative data on the ratio-scale associated with regions:

Visual-based simultaneous localization and mapping and global positioning system correction for geo-localization of a mobile robot

International Nuclear Information System (INIS)

Berrabah, Sid Ahmed; Baudoin, Yvan; Sahli, Hichem

2011-01-01

This paper introduces an approach combining visual-based simultaneous localization and mapping (V-SLAM) and global positioning system (GPS) correction for accurate multi-sensor localization of an outdoor mobile robot in geo-referenced maps. The proposed framework combines two extended Kalman filters (EKF); the first one, referred to as the integration filter, is dedicated to the improvement of the GPS localization based on data from an inertial navigation system and wheels' encoders. The second EKF implements the V-SLAM process. The linear and angular velocities in the dynamic model of the V-SLAM EKF filter are given by the GPS/INS/Encoders integration filter. On the other hand, the output of the V-SLAM EKF filter is used to update the dynamics estimation in the integration filter and therefore the geo-referenced localization. This solution increases the accuracy and the robustness of the positioning during GPS outage and allows SLAM in less featured environments

A new mapping function in table-mounted eye tracker

Science.gov (United States)

Tong, Qinqin; Hua, Xiao; Qiu, Jian; Luo, Kaiqing; Peng, Li; Han, Peng

2018-01-01

Eye tracker is a new apparatus of human-computer interaction, which has caught much attention in recent years. Eye tracking technology is to obtain the current subject's "visual attention (gaze)" direction by using mechanical, electronic, optical, image processing and other means of detection. While the mapping function is one of the key technology of the image processing, and is also the determination of the accuracy of the whole eye tracker system. In this paper, we present a new mapping model based on the relationship among the eyes, the camera and the screen that the eye gazed. Firstly, according to the geometrical relationship among the eyes, the camera and the screen, the framework of mapping function between the pupil center and the screen coordinate is constructed. Secondly, in order to simplify the vectors inversion of the mapping function, the coordinate of the eyes, the camera and screen was modeled by the coaxial model systems. In order to verify the mapping function, corresponding experiment was implemented. It is also compared with the traditional quadratic polynomial function. And the results show that our approach can improve the accuracy of the determination of the gazing point. Comparing with other methods, this mapping function is simple and valid.

The Visual System

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Full Text Available ... search for current job openings visit HHS USAJobs Home » NEI for Kids » The Visual System Listen All ... up to 28,800 times a day! NEI Home Contact Us A-Z Site Map NEI on ...

Map It Then Write It

Science.gov (United States)

Lott, Kimberly; Read, Sylvia

2015-01-01

All writing begins with ideas, but young students often need visual cues to help them organize their thoughts before beginning to write. For this reason, many elementary teachers use graphic organizers or thinking maps to help students visualize patterns and organize their ideas within the different genres of writing. Graphic organizers such as…

Development of an in vivo visual robot system with a magnetic anchoring mechanism and a lens cleaning mechanism for laparoendoscopic single-site surgery (LESS).

Science.gov (United States)

Feng, Haibo; Dong, Dinghui; Ma, Tengfei; Zhuang, Jinlei; Fu, Yili; Lv, Yi; Li, Liyi

2017-12-01

Surgical robot systems which can significantly improve surgical procedures have been widely used in laparoendoscopic single-site surgery (LESS). For a relative complex surgical procedure, the development of an in vivo visual robot system for LESS can effectively improve the visualization for surgical robot systems. In this work, an in vivo visual robot system with a new mechanism for LESS was investigated. A finite element method (FEM) analysis was carried out to ensure the safety of the in vivo visual robot during the movement, which was the most important concern for surgical purposes. A master-slave control strategy was adopted, in which the control model was established by off-line experiments. The in vivo visual robot system was verified by using a phantom box. The experiment results show that the robot system can successfully realize the expected functionalities and meet the demands of LESS. The experiment results indicate that the in vivo visual robot with high manipulability has great potential in clinical application. Copyright © 2017 John Wiley & Sons, Ltd.

Individualization of 2D color maps for people with color vision deficiencies

KAUST Repository

Waldin, Nicholas; Bernhard, Matthias; Rautek, Peter; Viola, Ivan

2016-01-01

2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

Individualization of 2D color maps for people with color vision deficiencies

KAUST Repository

Waldin, Nicholas

2016-12-13

2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

A Web-based Visualization System for Three Dimensional Geological Model using Open GIS

Science.gov (United States)

Nemoto, T.; Masumoto, S.; Nonogaki, S.

2017-12-01

A three dimensional geological model is an important information in various fields such as environmental assessment, urban planning, resource development, waste management and disaster mitigation. In this study, we have developed a web-based visualization system for 3D geological model using free and open source software. The system has been successfully implemented by integrating web mapping engine MapServer and geographic information system GRASS. MapServer plays a role of mapping horizontal cross sections of 3D geological model and a topographic map. GRASS provides the core components for management, analysis and image processing of the geological model. Online access to GRASS functions has been enabled using PyWPS that is an implementation of WPS (Web Processing Service) Open Geospatial Consortium (OGC) standard. The system has two main functions. Two dimensional visualization function allows users to generate horizontal and vertical cross sections of 3D geological model. These images are delivered via WMS (Web Map Service) and WPS OGC standards. Horizontal cross sections are overlaid on the topographic map. A vertical cross section is generated by clicking a start point and an end point on the map. Three dimensional visualization function allows users to visualize geological boundary surfaces and a panel diagram. The user can visualize them from various angles by mouse operation. WebGL is utilized for 3D visualization. WebGL is a web technology that brings hardware-accelerated 3D graphics to the browser without installing additional software. The geological boundary surfaces can be downloaded to incorporate the geologic structure in a design on CAD and model for various simulations. This study was supported by JSPS KAKENHI Grant Number JP16K00158.

Automatically Annotated Mapping for Indoor Mobile Robot Applications

DEFF Research Database (Denmark)

Özkil, Ali Gürcan; Howard, Thomas J.

2012-01-01

of 2D visual tags allows encoding information physically at places-of-interest. Moreover, using physical characteristics of the visual tags (i.e. paper size) is exploited to recover relative poses of the tags in the environment using a simple camera. This method extends tag encoding to simultaneous......This paper presents a new and practical method for mapping and annotating indoor environments for mobile robot use. The method makes use of 2D occupancy grid maps for metric representation, and topology maps to indicate the connectivity of the ‘places-of-interests’ in the environment. Novel use...

Visualizing guided tours

DEFF Research Database (Denmark)

Poulsen, Signe Herbers; Fjord-Larsen, Mads; Hansen, Frank Allan

This paper identifies several problems with navigating and visualizing guided tours in traditional hypermedia systems. We discuss solutions to these problems, including the representation of guided tours as 3D metro maps with content preview. Issues regarding navigation and disorientation...

Map-based mobile services design, interaction and usability

CERN Document Server

Meng, Liqiu; Winter, Stephan; Popovich, Vasily

2008-01-01

This book reports the newest research and technical achievements on the following theme blocks: Design of mobile map services and its constraints; Typology and usability of mobile map services; Visualization solutions on small displays for time-critical tasks; Mobile map users; Interaction and adaptation in mobile environments; and Applications of map-based mobile services.

Development and validation of an achievement test in introductory quantum mechanics: The Quantum Mechanics Visualization Instrument (QMVI)

Science.gov (United States)

Cataloglu, Erdat

The purpose of this study was to construct a valid and reliable multiple-choice achievement test to assess students' understanding of core concepts of introductory quantum mechanics. Development of the Quantum Mechanics Visualization Instrument (QMVI) occurred across four successive semesters in 1999--2001. During this time 213 undergraduate and graduate students attending the Pennsylvania State University (PSU) at University Park and Arizona State University (ASU) participated in this development and validation study. Participating students were enrolled in four distinct groups of courses: Modern Physics, Undergraduate Quantum Mechanics, Graduate Quantum Mechanics, and Chemistry Quantum Mechanics. Expert panels of professors of physics experienced in teaching quantum mechanics courses and graduate students in physics and science education established the core content and assisted in the validating of successive versions of the 24-question QMVI. Instrument development was guided by procedures outlined in the Standards for Educational and Psychological Testing (AERA-APA-NCME, 1999). Data gathered in this study provided information used in the development of successive versions of the QMVI. Data gathered in the final phase of administration of the QMVI also provided evidence that the intended score interpretation of the QMVI achievement test is valid and reliable. A moderate positive correlation coefficient of 0.49 was observed between the students' QMVI scores and their confidence levels. Analyses of variance indicated that students' scores in Graduate Quantum Mechanics and Undergraduate Quantum Mechanics courses were significantly higher than the mean scores of students in Modern Physics and Chemistry Quantum Mechanics courses (p important factor for students in acquiring a successful understanding of quantum mechanics.

Mining Concept Maps to Understand University Students' Learning

Science.gov (United States)

Yoo, Jin Soung; Cho, Moon-Heum

2012-01-01

Concept maps, visual representations of knowledge, are used in an educational context as a way to represent students' knowledge, and identify mental models of students; however there is a limitation of using concept mapping due to its difficulty to evaluate the concept maps. A concept map has a complex structure which is composed of concepts and…

Visualizing the mapped ion pathway through the Na,K-ATPase pump.

Science.gov (United States)

Takeuchi, Ayako; Reyes, Nicolás; Artigas, Pablo; Gadsby, David C

2009-11-01

The Na(+),K(+)-ATPase pump achieves thermodynamically uphill exchange of cytoplasmic Na(+) ions for extracellular K(+) ions by using ATP-mediated phosphorylation, followed by autodephosphorylation, to power conformational changes that allow ion access to the pump's binding sites from only one side of the membrane at a time. Formally, the pump behaves like an ion channel with two tightly coupled gates that are constrained to open and close alternately. The marine agent palytoxin disrupts this coupling, allowing both gates to sometimes be open, so temporarily transforming a pump into an ion channel. We made a cysteine scan of Na(+),K(+)-ATPase transmembrane (TM) segments TM1 to TM6, and used recordings of Na(+) current flow through palytoxin-bound pump-channels to monitor accessibility of introduced cysteine residues via their reaction with hydrophilic methanethiosulfonate (MTS) reagents. To visualize the open-channel pathway, the reactive positions were mapped onto a homology model of Na(+),K(+)-ATPase based on the structure of the related sarcoplasmicand endoplasmic-reticulum (SERCA) Ca(2+)-ATPase in a BeF(3)(-)-trapped state,(1,2) in which the extra-cytoplasmic gate is wide open (although the cytoplasmic access pathway is firmly shut). The results revealed a single unbroken chain of reactive positions that traverses the pump from the extracellular surface to the cytoplasm, comprises residues from TM1, TM2, TM4 and TM6, and passes through the equivalent of cation binding site II in SERCA, but not through site I. Cavity search analysis of the homology model validated its use for mapping the data by yielding a calculated extra-cytoplasmic pathway surrounded by MTS-reactive residues. As predicted by previous experimental results, that calculated extra-cytoplasmic pathway abruptly broadens above residue T806, at the outermost end of TM6 that forms the floor of the extracellular-facing vestibule. These findings provide a structural basis for further understanding cation

Visualizing the mapped ion pathway through the Na,K-ATPase pump

Science.gov (United States)

Takeuchi, Ayako; Reyes, Nicolás; Artigas, Pablo; Gadsby, David C.

2009-01-01

The Na+,K+-ATPase pump achieves thermodynamically uphill exchange of cytoplasmic Na+ ions for extracellular K+ ions by using ATP-mediated phosphorylation, followed by autodephosphorylation, to power conformational changes that allow ion access to the pump's binding sites from only one side of the membrane at a time. Formally, the pump behaves like an ion channel with two tightly coupled gates that are constrained to open and close alternately. The marine agent palytoxin disrupts this coupling, allowing both gates to sometimes be open, so temporarily transforming a pump into an ion channel. We made a cysteine scan of Na+,K+-ATPase transmembrane (TM) segments TM1 to TM6, and used recordings of Na+ current flow through palytoxin-bound pump-channels to monitor accessibility of introduced cysteine residues via their reaction with hydrophilic methanethiosulfonate (MTS) reagents. To visualize the open-channel pathway, the reactive positions were mapped onto a homology model of Na+,K+-ATPase based on the structure of the related sarcoplasmic- and endoplasmic-reticulum (SERCA) Ca2+-ATPase in a BeF3−-trapped state1,2, in which the extra-cytoplasmic gate is wide open (although the cytoplasmic access pathway is firmly shut). The results revealed a single unbroken chain of reactive positions that traverses the pump from the extracellular surface to the cytoplasm, comprises residues from TM1, TM2, TM4, and TM6, and passes through the equivalent of cation binding site II in SERCA, but not through site I. Cavity search analysis of the homology model validated its use for mapping the data by yielding a calculated extra-cytoplasmic pathway surrounded by MTS-reactive residues. As predicted by previous experimental results, that calculated extra-cytoplasmic pathway abruptly broadens above residue T806, at the outermost end of TM6 which forms the floor of the extracellular-facing vestibule. These findings provide a structural basis for further understanding cation translocation by

Distributed Monocular SLAM for Indoor Map Building

OpenAIRE

Ruwan Egodagamage; Mihran Tuceryan

2017-01-01

Utilization and generation of indoor maps are critical elements in accurate indoor tracking. Simultaneous Localization and Mapping (SLAM) is one of the main techniques for such map generation. In SLAM an agent generates a map of an unknown environment while estimating its location in it. Ubiquitous cameras lead to monocular visual SLAM, where a camera is the only sensing device for the SLAM process. In modern applications, multiple mobile agents may be involved in the generation of such maps,...

Early visual cortex reflects initiation and maintenance of task set

Science.gov (United States)

Elkhetali, Abdurahman S.; Vaden, Ryan J.; Pool, Sean M.

2014-01-01

The human brain is able to process information flexibly, depending on a person's task. The mechanisms underlying this ability to initiate and maintain a task set are not well understood, but they are important for understanding the flexibility of human behavior and developing therapies for disorders involving attention. Here we investigate the differential roles of early visual cortical areas in initiating and maintaining a task set. Using functional Magnetic Resonance Imaging (fMRI), we characterized three different components of task set-related, but trial-independent activity in retinotopically mapped areas of early visual cortex, while human participants performed attention demanding visual or auditory tasks. These trial-independent effects reflected: (1) maintenance of attention over a long duration, (2) orienting to a cue, and (3) initiation of a task set. Participants performed tasks that differed in the modality of stimulus to be attended (auditory or visual) and in whether there was a simultaneous distractor (auditory only, visual only, or simultaneous auditory and visual). We found that patterns of trial-independent activity in early visual areas (V1, V2, V3, hV4) depend on attended modality, but not on stimuli. Further, different early visual areas play distinct roles in the initiation of a task set. In addition, activity associated with maintaining a task set tracks with a participant's behavior. These results show that trial-independent activity in early visual cortex reflects initiation and maintenance of a person's task set. PMID:25485712

Cognitive Mapping Based on Conjunctive Representations of Space and Movement

Directory of Open Access Journals (Sweden)

Taiping Zeng

2017-11-01

Full Text Available It is a challenge to build robust simultaneous localization and mapping (SLAM system in dynamical large-scale environments. Inspired by recent findings in the entorhinal–hippocampal neuronal circuits, we propose a cognitive mapping model that includes continuous attractor networks of head-direction cells and conjunctive grid cells to integrate velocity information by conjunctive encodings of space and movement. Visual inputs from the local view cells in the model provide feedback cues to correct drifting errors of the attractors caused by the noisy velocity inputs. We demonstrate the mapping performance of the proposed cognitive mapping model on an open-source dataset of 66 km car journey in a 3 km × 1.6 km urban area. Experimental results show that the proposed model is robust in building a coherent semi-metric topological map of the entire urban area using a monocular camera, even though the image inputs contain various changes caused by different light conditions and terrains. The results in this study could inspire both neuroscience and robotic research to better understand the neural computational mechanisms of spatial cognition and to build robust robotic navigation systems in large-scale environments.

Quantitative Mapping of Mechanisms for Photoinitiated Coating Degradation

DEFF Research Database (Denmark)

Kiil, Søren

2015-01-01

be used toimplement the various effects of water on the degradation mechanisms of cross-linked coatings is also presented and experiments to test the approach are suggested. Additionally, simulations with an existing degradation model for an epoxy–amine coating are used to map the influence of model......This work concerns the mathematical modeling of photoinitiated coating degradation. Using experimental evidence available, some of the most importantassumptions underlying existing models for the rmoset coatings are analyzed and suggestions for further work provided. A modeling approach that can...... parameters on the lag time (i.e., the time passing prior to the onset of erosion) and the stable erosion rate. The simulation results can be used in the optimization of UV radiation-induced intercoat adhesion losses, which are often observed in multilayer coating systems based on top coated epoxy coatings...

Mapping of genomic EGFRvIII deletions in glioblastoma: insight into rearrangement mechanisms and biomarker development.

Science.gov (United States)

Koga, Tomoyuki; Li, Bin; Figueroa, Javier M; Ren, Bing; Chen, Clark C; Carter, Bob S; Furnari, Frank B

2018-04-12

Epidermal growth factor receptor (EGFR) variant III (vIII) is the most common oncogenic rearrangement in glioblastoma (GBM) generated by deletion of exons two to seven of EGFR. The proximal breakpoints occur in variable positions within the 123-kb intron one, presenting significant challenges in terms of PCR-based mapping. Molecular mechanisms underlying these deletions remain unclear. We determined the presence of EGFRvIII and its breakpoints for 29 GBM samples using quantitative polymerase chain reaction (qPCR), arrayed PCR mapping, Sanger sequencing, and whole genome sequencing (WGS). Patient-specific breakpoint PCR was performed on tumors, plasma and cerebrospinal fluid (CSF) samples. The breakpoint sequences and single nucleotide polymorphisms (SNPs) were analyzed to elucidate the underlying biogenic mechanism. PCR mapping and WGS independently unveiled eight EGFRvIII breakpoints in six tumors. Patient-specific primers yielded EGFRvIII PCR amplicons in matched tumors, and in cell-free DNA (cfDNA) from a CSF sample, but not in cfDNA or extracellular-vesicle DNA from plasma. The breakpoint analysis revealed nucleotide insertions in four, an insertion of a region outside of EGFR locus in one, microhomologies in three, as well as a duplication or an inversion accompanied by microhomologies in two, suggestive of distinct DNA repair mechanisms. In the GBM samples that harbored distinct breakpoints, the SNP compositions of EGFRvIII and amplified non-vIII EGFR were identical, suggesting that these rearrangements arose from amplified non-vIII EGFR. Our approach efficiently "fingerprints" each sample's EGFRvIII breakpoints. Breakpoint sequence analyses suggest that independent breakpoints arose from precursor amplified non-vIII EGFR through different DNA repair mechanisms.

Comparable mechanisms of working memory interference by auditory and visual motion in youth and aging.

Science.gov (United States)

Mishra, Jyoti; Zanto, Theodore; Nilakantan, Aneesha; Gazzaley, Adam

2013-08-01

Intrasensory interference during visual working memory (WM) maintenance by object stimuli (such as faces and scenes), has been shown to negatively impact WM performance, with greater detrimental impacts of interference observed in aging. Here we assessed age-related impacts by intrasensory WM interference from lower-level stimulus features such as visual and auditory motion stimuli. We consistently found that interference in the form of ignored distractions and secondary task interruptions presented during a WM maintenance period, degraded memory accuracy in both the visual and auditory domain. However, in contrast to prior studies assessing WM for visual object stimuli, feature-based interference effects were not observed to be significantly greater in older adults. Analyses of neural oscillations in the alpha frequency band further revealed preserved mechanisms of interference processing in terms of post-stimulus alpha suppression, which was observed maximally for secondary task interruptions in visual and auditory modalities in both younger and older adults. These results suggest that age-related sensitivity of WM to interference may be limited to complex object stimuli, at least at low WM loads. Copyright © 2013 Elsevier Ltd. All rights reserved.

Visual cognition

Energy Technology Data Exchange (ETDEWEB)

Pinker, S.

1985-01-01

This collection of research papers on visual cognition first appeared as a special issue of Cognition: International Journal of Cognitive Science. The study of visual cognition has seen enormous progress in the past decade, bringing important advances in our understanding of shape perception, visual imagery, and mental maps. Many of these discoveries are the result of converging investigations in different areas, such as cognitive and perceptual psychology, artificial intelligence, and neuropsychology. This volume is intended to highlight a sample of work at the cutting edge of this research area for the benefit of students and researchers in a variety of disciplines. The tutorial introduction that begins the volume is designed to help the nonspecialist reader bridge the gap between the contemporary research reported here and earlier textbook introductions or literature reviews.

Geoplotlib: a Python Toolbox for Visualizing Geographical Data

OpenAIRE

Cuttone, Andrea; Lehmann, Sune; Larsen, Jakob Eg

2016-01-01

We introduce geoplotlib, an open-source python toolbox for visualizing geographical data. geoplotlib supports the development of hardware-accelerated interactive visualizations in pure python, and provides implementations of dot maps, kernel density estimation, spatial graphs, Voronoi tesselation, shapefiles and many more common spatial visualizations. We describe geoplotlib design, functionalities and use cases.

Supporting interactive visual analytics of energy behavior in buildings through affine visualizations

DEFF Research Database (Denmark)

Nielsen, Matthias; Brewer, Robert S.; Grønbæk, Kaj

2016-01-01

Domain experts dealing with big data are typically not familiar with advanced data mining tools. This especially holds true for domain experts within energy management. In this paper, we introduce a visual analytics approach that empowers such users to visually analyze energy behavior based......Viz, that interactively maps data from real world buildings. It is an overview +detail inter-active visual analytics tool supporting both rapid ad hoc explorations and structured evaluation of hypotheses about patterns and anomalies in resource consumption data mixed with occupant survey data. We have evaluated...... the approach with five domain experts within energy management, and further with 10 data analytics experts and found that it was easily attainable and that it supported visual analysis of mixed consumption and survey data. Finally, we discuss future perspectives of affine visual analytics for mixed...

FuncTree: Functional Analysis and Visualization for Large-Scale Omics Data.

Directory of Open Access Journals (Sweden)

Takeru Uchiyama

Full Text Available Exponential growth of high-throughput data and the increasing complexity of omics information have been making processing and interpreting biological data an extremely difficult and daunting task. Here we developed FuncTree (http://bioviz.tokyo/functree, a web-based application for analyzing and visualizing large-scale omics data, including but not limited to genomic, metagenomic, and transcriptomic data. FuncTree allows user to map their omics data onto the "Functional Tree map", a predefined circular dendrogram, which represents the hierarchical relationship of all known biological functions defined in the KEGG database. This novel visualization method allows user to overview the broad functionality of their data, thus allowing a more accurate and comprehensive understanding of the omics information. FuncTree provides extensive customization and calculation methods to not only allow user to directly map their omics data to identify the functionality of their data, but also to compute statistically enriched functions by comparing it to other predefined omics data. We have validated FuncTree's analysis and visualization capability by mapping pan-genomic data of three different types of bacterial genera, metagenomic data of the human gut, and transcriptomic data of two different types of human cell expression. All three mapping strongly confirms FuncTree's capability to analyze and visually represent key functional feature of the omics data. We believe that FuncTree's capability to conduct various functional calculations and visualizing the result into a holistic overview of biological function, would make it an integral analysis/visualization tool for extensive omics base research.

Identification of Characteristic Macromolecules of Escherichia coli Genotypes by Atomic Force Microscope Nanoscale Mechanical Mapping

Science.gov (United States)

Chang, Alice Chinghsuan; Liu, Bernard Haochih

2018-02-01

The categorization of microbial strains is conventionally based on the molecular method, and seldom are the morphological characteristics in the bacterial strains studied. In this research, we revealed the macromolecular structures of the bacterial surface via AFM mechanical mapping, whose resolution was not only determined by the nanoscale tip size but also the mechanical properties of the specimen. This technique enabled the nanoscale study of membranous structures of microbial strains with simple specimen preparation and flexible working environments, which overcame the multiple restrictions in electron microscopy and label-enable biochemical analytical methods. The characteristic macromolecules located among cellular surface were considered as surface layer proteins and were found to be specific to the Escherichia coli genotypes, from which the averaged molecular sizes were characterized with diameters ranging from 38 to 66 nm, and the molecular shapes were kidney-like or round. In conclusion, the surface macromolecular structures have unique characteristics that link to the E. coli genotype, which suggests that the genomic effects on cellular morphologies can be rapidly identified using AFM mechanical mapping. [Figure not available: see fulltext.

A novel visual-inertial monocular SLAM

Science.gov (United States)

Yue, Xiaofeng; Zhang, Wenjuan; Xu, Li; Liu, JiangGuo

2018-02-01

With the development of sensors and computer vision research community, cameras, which are accurate, compact, wellunderstood and most importantly cheap and ubiquitous today, have gradually been at the center of robot location. Simultaneous localization and mapping (SLAM) using visual features, which is a system getting motion information from image acquisition equipment and rebuild the structure in unknown environment. We provide an analysis of bioinspired flights in insects, employing a novel technique based on SLAM. Then combining visual and inertial measurements to get high accuracy and robustness. we present a novel tightly-coupled Visual-Inertial Simultaneous Localization and Mapping system which get a new attempt to address two challenges which are the initialization problem and the calibration problem. experimental results and analysis show the proposed approach has a more accurate quantitative simulation of insect navigation, which can reach the positioning accuracy of centimeter level.

What Google Maps can do for biomedical data dissemination: examples and a design study.

Science.gov (United States)

Jianu, Radu; Laidlaw, David H

2013-05-04

Biologists often need to assess whether unfamiliar datasets warrant the time investment required for more detailed exploration. Basing such assessments on brief descriptions provided by data publishers is unwieldy for large datasets that contain insights dependent on specific scientific questions. Alternatively, using complex software systems for a preliminary analysis may be deemed as too time consuming in itself, especially for unfamiliar data types and formats. This may lead to wasted analysis time and discarding of potentially useful data. We present an exploration of design opportunities that the Google Maps interface offers to biomedical data visualization. In particular, we focus on synergies between visualization techniques and Google Maps that facilitate the development of biological visualizations which have both low-overhead and sufficient expressivity to support the exploration of data at multiple scales. The methods we explore rely on displaying pre-rendered visualizations of biological data in browsers, with sparse yet powerful interactions, by using the Google Maps API. We structure our discussion around five visualizations: a gene co-regulation visualization, a heatmap viewer, a genome browser, a protein interaction network, and a planar visualization of white matter in the brain. Feedback from collaborative work with domain experts suggests that our Google Maps visualizations offer multiple, scale-dependent perspectives and can be particularly helpful for unfamiliar datasets due to their accessibility. We also find that users, particularly those less experienced with computer use, are attracted by the familiarity of the Google Maps API. Our five implementations introduce design elements that can benefit visualization developers. We describe a low-overhead approach that lets biologists access readily analyzed views of unfamiliar scientific datasets. We rely on pre-computed visualizations prepared by data experts, accompanied by sparse and intuitive

Self-Taught Visually-Guided Pointing for a Humanoid Robot

National Research Council Canada - National Science Library

Marjanovic, Matthew; Scassellati, Brian; Williamson, Matthew

2006-01-01

.... This task requires systems for learning saccade to visual targets, generating smooth arm trajectories, locating the arm in the visual field, and learning the map between gaze direction and correct...

Dynamic Data Visualization with Weave and Brain Choropleths.

Directory of Open Access Journals (Sweden)

Dianne Patterson

Full Text Available This article introduces the neuroimaging community to the dynamic visualization workbench, Weave (https://www.oicweave.org/, and a set of enhancements to allow the visualization of brain maps. The enhancements comprise a set of brain choropleths and the ability to display these as stacked slices, accessible with a slider. For the first time, this allows the neuroimaging community to take advantage of the advanced tools already available for exploring geographic data. Our brain choropleths are modeled after widely used geographic maps but this mashup of brain choropleths with extant visualization software fills an important neuroinformatic niche. To date, most neuroinformatic tools have provided online databases and atlases of the brain, but not good ways to display the related data (e.g., behavioral, genetic, medical, etc. The extension of the choropleth to brain maps allows us to leverage general-purpose visualization tools for concurrent exploration of brain images and related data. Related data can be represented as a variety of tables, charts and graphs that are dynamically linked to each other and to the brain choropleths. We demonstrate that the simplified region-based analyses that underlay choropleths can provide insights into neuroimaging data comparable to those achieved by using more conventional methods. In addition, the interactive interface facilitates additional insights by allowing the user to filter, compare, and drill down into the visual representations of the data. This enhanced data visualization capability is useful during the initial phases of data analysis and the resulting visualizations provide a compelling way to publish data as an online supplement to journal articles.

Using Symmetrical Regions of Interest to Improve Visual SLAM

NARCIS (Netherlands)

Kootstra, Geert; Schomaker, Lambertus

2009-01-01

Simultaneous Localization and Mapping (SLAM) based on visual information is a challenging problem. One of the main problems with visual SLAM is to find good quality landmarks, that can be detected despite noise and small changes in viewpoint. Many approaches use SIFT interest points as visual

Guidelines for visualizing and annotating rule-based models†

Science.gov (United States)

Chylek, Lily A.; Hu, Bin; Blinov, Michael L.; Emonet, Thierry; Faeder, James R.; Goldstein, Byron; Gutenkunst, Ryan N.; Haugh, Jason M.; Lipniacki, Tomasz; Posner, Richard G.; Yang, Jin; Hlavacek, William S.

2011-01-01

Rule-based modeling provides a means to represent cell signaling systems in a way that captures site-specific details of molecular interactions. For rule-based models to be more widely understood and (re)used, conventions for model visualization and annotation are needed. We have developed the concepts of an extended contact map and a model guide for illustrating and annotating rule-based models. An extended contact map represents the scope of a model by providing an illustration of each molecule, molecular component, direct physical interaction, post-translational modification, and enzyme-substrate relationship considered in a model. A map can also illustrate allosteric effects, structural relationships among molecular components, and compartmental locations of molecules. A model guide associates elements of a contact map with annotation and elements of an underlying model, which may be fully or partially specified. A guide can also serve to document the biological knowledge upon which a model is based. We provide examples of a map and guide for a published rule-based model that characterizes early events in IgE receptor (FcεRI) signaling. We also provide examples of how to visualize a variety of processes that are common in cell signaling systems but not considered in the example model, such as ubiquitination. An extended contact map and an associated guide can document knowledge of a cell signaling system in a form that is visual as well as executable. As a tool for model annotation, a map and guide can communicate the content of a model clearly and with precision, even for large models. PMID:21647530

Guidelines for visualizing and annotating rule-based models.

Science.gov (United States)

Chylek, Lily A; Hu, Bin; Blinov, Michael L; Emonet, Thierry; Faeder, James R; Goldstein, Byron; Gutenkunst, Ryan N; Haugh, Jason M; Lipniacki, Tomasz; Posner, Richard G; Yang, Jin; Hlavacek, William S

2011-10-01

Rule-based modeling provides a means to represent cell signaling systems in a way that captures site-specific details of molecular interactions. For rule-based models to be more widely understood and (re)used, conventions for model visualization and annotation are needed. We have developed the concepts of an extended contact map and a model guide for illustrating and annotating rule-based models. An extended contact map represents the scope of a model by providing an illustration of each molecule, molecular component, direct physical interaction, post-translational modification, and enzyme-substrate relationship considered in a model. A map can also illustrate allosteric effects, structural relationships among molecular components, and compartmental locations of molecules. A model guide associates elements of a contact map with annotation and elements of an underlying model, which may be fully or partially specified. A guide can also serve to document the biological knowledge upon which a model is based. We provide examples of a map and guide for a published rule-based model that characterizes early events in IgE receptor (FcεRI) signaling. We also provide examples of how to visualize a variety of processes that are common in cell signaling systems but not considered in the example model, such as ubiquitination. An extended contact map and an associated guide can document knowledge of a cell signaling system in a form that is visual as well as executable. As a tool for model annotation, a map and guide can communicate the content of a model clearly and with precision, even for large models.

Remote sensing and vegetation mapping in South Africa

Directory of Open Access Journals (Sweden)

M. L. Jarman

1983-12-01

Full Text Available The kinds of imagery, types of data and general relationships between scale of study, scale of mapping and scale of remote sensing products that are appropriate to the South African situation for visual and digital analysis are presented. The type of remote sensing product and processing, the type of field exercise appropriate to each, and the purpose of producing maps at each scale are discussed. Lack of repetitive imagery to date has not allowed for the full investigation of monitoring potential and careful planning at national level is needed to ensure availability of imagery for monitoring purposes. Map production processes which are rapid and accurate should be utilized. An integrated approach to vegetation mapping and surveying, which incorporates the best features of both visual and digital processing, is recommended for use.

Mixed Map Labeling

Directory of Open Access Journals (Sweden)

Maarten Löffler

2016-12-01

Full Text Available Point feature map labeling is a geometric visualization problem, in which a set of input points must be labeled with a set of disjoint rectangles (the bounding boxes of the label texts. It is predominantly motivated by label placement in maps but it also has other visualization applications. Typically, labeling models either use internal labels, which must touch their feature point, or external (boundary labels, which are placed outside the input image and which are connected to their feature points by crossing-free leader lines. In this paper we study polynomial-time algorithms for maximizing the number of internal labels in a mixed labeling model that combines internal and external labels. The model requires that all leaders are parallel to a given orientation θ ∈ [0, 2π, the value of which influences the geometric properties and hence the running times of our algorithms.

Methodological Advances in Bibliometric Mapping of Science

NARCIS (Netherlands)

N.J.P. van Eck (Nees Jan)

2011-01-01

textabstractBibliometric mapping of science is concerned with quantitative methods for visually representing scientific literature based on bibliographic data. Since the first pioneering efforts in the 1970s, a large number of methods and techniques for bibliometric mapping have been proposed and

Evaluating an animated and static time series map of District Six: A ...

African Journals Online (AJOL)

Visualization of spatial information is an important aspect in the representation of map displays. Maps today are visually adapted to a variety of mediums in displaying spatial information temporally and as time series phenomena. GIS technology has incorporated tools for analysing these spatio-temporal trends. However ...

Spatial and Global Sensory Suppression Mapping Encompassing the Central 10° Field in Anisometropic Amblyopia.

Science.gov (United States)

Li, Jingjing; Li, Jinrong; Chen, Zidong; Liu, Jing; Yuan, Junpeng; Cai, Xiaoxiao; Deng, Daming; Yu, Minbin

2017-01-01

We investigate the efficacy of a novel dichoptic mapping paradigm in evaluating visual function of anisometropic amblyopes. Using standard clinical measures of visual function (visual acuity, stereo acuity, Bagolini lenses, and neutral density filters) and a novel quantitative mapping technique, 26 patients with anisometropic amblyopia (mean age = 19.15 ± 4.42 years) were assessed. Two additional psychophysical interocular suppression measurements were tested with dichoptic global motion coherence and binocular phase combination tasks. Luminance reduction was achieved by placing neutral density filters in front of the normal eye. Our study revealed that suppression changes across the central 10° visual field by mean luminance modulation in amblyopes as well as normal controls. Using simulation and an elimination of interocular suppression, we identified a novel method to effectively reflect the distribution of suppression in anisometropic amblyopia. Additionally, the new quantitative mapping technique was in good agreement with conventional clinical measures, such as interocular acuity difference (P suppression with dichoptic mapping paradigm and the results of the other two psychophysical methods (suppression mapping versus binocular phase combination, P suppression mapping versus global motion coherence, P = 0.005). The dichoptic suppression mapping technique is an effective method to represent impaired visual function in patients with anisometropic amblyopia. It offers a potential in "micro-"antisuppression mapping tests and therapies for amblyopia.

Suppressive mechanisms in visual motion processing: From perception to intelligence.

Science.gov (United States)

Tadin, Duje

2015-10-01

Perception operates on an immense amount of incoming information that greatly exceeds the brain's processing capacity. Because of this fundamental limitation, the ability to suppress irrelevant information is a key determinant of perceptual efficiency. Here, I will review a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. These spatial suppression mechanisms are adaptive, operating only when sensory inputs are sufficiently robust to guarantee visibility. Converging correlational and causal evidence links these behavioral results with inhibitory center-surround mechanisms, namely those in cortical area MT. Spatial suppression is abnormally weak in several special populations, including the elderly and individuals with schizophrenia-a deficit that is evidenced by better-than-normal direction discriminations of large moving stimuli. Theoretical work shows that this abnormal weakening of spatial suppression should result in motion segregation deficits, but direct behavioral support of this hypothesis is lacking. Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, I will discuss recent research that shows individual differences in spatial suppression of motion signals strongly predict individual variations in IQ scores. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

TOXMAP®: Environmental Health Maps

Data.gov (United States)

U.S. Department of Health & Human Services — TOXMAP® is a Geographic Information System (GIS) that uses maps of the United States and Canada to help users visually explore data primarily from the EPA's Toxics...

On an elementary definition of visual saliency

DEFF Research Database (Denmark)

Loog, Marco

2008-01-01

Various approaches to computational modelling of bottom-up visual attention have been proposed in the past two decades. As part of this trend, researchers have studied ways to characterize the saliency map underlying many of these models. In more recent years, several definitions based on probabi......Various approaches to computational modelling of bottom-up visual attention have been proposed in the past two decades. As part of this trend, researchers have studied ways to characterize the saliency map underlying many of these models. In more recent years, several definitions based...... on probabilistic and information or decision theoretic considerations have been proposed. These provide experimentally successful, appealing, low-level, operational, and elementary definitions of visual saliency (see eg, Bruce, 2005 Neurocomputing 65 125 - 133). Here, I demonstrate that, in fact, all...

Comparison of animated jet stream visualizations

Science.gov (United States)

Nocke, Thomas; Hoffmann, Peter

2016-04-01

The visualization of 3D atmospheric phenomena in space and time is still a challenging problem. In particular, multiple solutions of animated jet stream visualizations have been produced in recent years, which were designed to visually analyze and communicate the jet and related impacts on weather circulation patterns and extreme weather events. This PICO integrates popular and new jet animation solutions and inter-compares them. The applied techniques (e.g. stream lines or line integral convolution) and parametrizations (color mapping, line lengths) are discussed with respect to visualization quality criteria and their suitability for certain visualization tasks (e.g. jet patterns and jet anomaly analysis, communicating its relevance for climate change).

The Tölz Temporal Topography Study: mapping the visual field across the life span. Part I: the topography of light detection and temporal-information processing.

Science.gov (United States)

Poggel, Dorothe A; Treutwein, Bernhard; Calmanti, Claudia; Strasburger, Hans

2012-08-01

Temporal performance parameters vary across the visual field. Their topographical distributions relative to each other and relative to basic visual performance measures and their relative change over the life span are unknown. Our goal was to characterize the topography and age-related change of temporal performance. We acquired visual field maps in 95 healthy participants (age: 10-90 years): perimetric thresholds, double-pulse resolution (DPR), reaction times (RTs), and letter contrast thresholds. DPR and perimetric thresholds increased with eccentricity and age; the periphery showed a more pronounced age-related increase than the center. RT increased only slightly and uniformly with eccentricity. It remained almost constant up to the age of 60, a marked change occurring only above 80. Overall, age was a poor predictor of functionality. Performance decline could be explained only in part by the aging of the retina and optic media. In Part II, we therefore examine higher visual and cognitive functions.

Brain F-18 FDG PET for localization of epileptogenic zones in frontal lobe epilepsy: visual assessment and statistical parametric mapping analysis

International Nuclear Information System (INIS)

Kim, Yu Kyeong; Lee, Dong Soo; Lee, Sang Kun; Chung, Chun Kee; Yeo, Jeong Seok; Chung, June Key; Lee, Myung Chul

2001-01-01

We evaluated the sensitivity of the F-18 FDG PET by visual assessment and statistical parametric mapping (SPM) analysis for the localization of the epileptogenic zones in frontal lobe epilepsy. Twenty-four patients with frontal lobe epilepsy were examined. All patients exhibited improvements after surgical resection (Engel class I or II). Upon pathological examination, 18 patients revealed cortical dysplasia, 4 patients revealed tumor, and 2 patients revealed cortical scar. The hypometabolic lesions were found in F-18 FDG PET by visual assessment and SPM analysis. On SPM analysis, cutoff threshold was changed. MRI showed structural lesions in 12 patients and normal results in the remaining 12. F-18 FDG PET correctly localized epileptogenic zones in 13 patients (54%) by visual assessment. Sensitivity of F-18 FDG PET in MR-negative patients (50%) was similar to that in MR-positive patients (67%). On SPM analysis, sensitivity deceased according to the decrease of p value. Using uncorrected p value of 0.05 as threshold, sensitivity of SPM analysis was 63%, which was not statistically different from that of visual assessment. F-18 FDG PET was sensitive in finding epileptogenic zones by revealing hypometabolic areas even in MR-negative patients with frontal lobe epilepsy as well as in MR-positive patients. SPM analysis showed comparable sensitivity to visual assessment and could be used as an aid in the diagnosis of epileptogenic zones in frontal lobe epilepsy

Visualization of diversity in large multivariate data sets.

Science.gov (United States)

Pham, Tuan; Hess, Rob; Ju, Crystal; Zhang, Eugene; Metoyer, Ronald

2010-01-01

Understanding the diversity of a set of multivariate objects is an important problem in many domains, including ecology, college admissions, investing, machine learning, and others. However, to date, very little work has been done to help users achieve this kind of understanding. Visual representation is especially appealing for this task because it offers the potential to allow users to efficiently observe the objects of interest in a direct and holistic way. Thus, in this paper, we attempt to formalize the problem of visualizing the diversity of a large (more than 1000 objects), multivariate (more than 5 attributes) data set as one worth deeper investigation by the information visualization community. In doing so, we contribute a precise definition of diversity, a set of requirements for diversity visualizations based on this definition, and a formal user study design intended to evaluate the capacity of a visual representation for communicating diversity information. Our primary contribution, however, is a visual representation, called the Diversity Map, for visualizing diversity. An evaluation of the Diversity Map using our study design shows that users can judge elements of diversity consistently and as or more accurately than when using the only other representation specifically designed to visualize diversity.

Rapid and minimum invasive functional brain mapping by real-time visualization of high gamma activity during awake craniotomy.

Science.gov (United States)

Ogawa, Hiroshi; Kamada, Kyousuke; Kapeller, Christoph; Hiroshima, Satoru; Prueckl, Robert; Guger, Christoph

2014-11-01

Electrocortical stimulation (ECS) is the gold standard for functional brain mapping during an awake craniotomy. The critical issue is to set aside enough time to identify eloquent cortices by ECS. High gamma activity (HGA) ranging between 80 and 120 Hz on electrocorticogram is assumed to reflect localized cortical processing. In this report, we used real-time HGA mapping and functional neuronavigation integrated with functional magnetic resonance imaging (fMRI) for rapid and reliable identification of motor and language functions. Four patients with intra-axial tumors in their dominant hemisphere underwent preoperative fMRI and lesion resection with an awake craniotomy. All patients showed significant fMRI activation evoked by motor and language tasks. During the craniotomy, we recorded electrocorticogram activity by placing subdural grids directly on the exposed brain surface. Each patient performed motor and language tasks and demonstrated real-time HGA dynamics in hand motor areas and parts of the inferior frontal gyrus. Sensitivity and specificity of HGA mapping were 100% compared with ECS mapping in the frontal lobe, which suggested HGA mapping precisely indicated eloquent cortices. We found different HGA dynamics of language tasks in frontal and temporal regions. Specificities of the motor and language-fMRI did not reach 85%. The results of HGA mapping was mostly consistent with those of ECS mapping, although fMRI tended to overestimate functional areas. This novel technique enables rapid and accurate identification of motor and frontal language areas. Furthermore, real-time HGA mapping sheds light on underlying physiological mechanisms related to human brain functions. Copyright © 2014 Elsevier Inc. All rights reserved.

Neural Anatomy of Primary Visual Cortex Limits Visual Working Memory.

Science.gov (United States)

Bergmann, Johanna; Genç, Erhan; Kohler, Axel; Singer, Wolf; Pearson, Joel

2016-01-01

Despite the immense processing power of the human brain, working memory storage is severely limited, and the neuroanatomical basis of these limitations has remained elusive. Here, we show that the stable storage limits of visual working memory for over 9 s are bound by the precise gray matter volume of primary visual cortex (V1), defined by fMRI retinotopic mapping. Individuals with a bigger V1 tended to have greater visual working memory storage. This relationship was present independently for both surface size and thickness of V1 but absent in V2, V3 and for non-visual working memory measures. Additional whole-brain analyses confirmed the specificity of the relationship to V1. Our findings indicate that the size of primary visual cortex plays a critical role in limiting what we can hold in mind, acting like a gatekeeper in constraining the richness of working mental function. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Visualizing the Geography of the Diseases of China: Western Disease Maps from Analytical Tools to Tools of Empire, Sovereignty, and Public Health Propaganda, 1878-1929.

Science.gov (United States)

Hanson, Marta

2017-09-01

Argument This article analyzes for the first time the earliest western maps of diseases in China spanning fifty years from the late 1870s to the end of the 1920s. The 24 featured disease maps present a visual history of the major transformations in modern medicine from medical geography to laboratory medicine wrought on Chinese soil. These medical transformations occurred within new political formations from the Qing dynasty (1644-1911) to colonialism in East Asia (Hong Kong, Taiwan, Manchuria, Korea) and hypercolonialism within China (Tianjin, Shanghai, Amoy) as well as the new Republican Chinese nation state (1912-49). As a subgenre of persuasive graphics, physicians marshaled disease maps for various rhetorical functions within these different political contexts. Disease maps in China changed from being mostly analytical tools to functioning as tools of empire, national sovereignty, and public health propaganda legitimating new medical concepts, public health interventions, and political structures governing over human and non-human populations.

CMIS: Crime Map Information System for Safety Environment

Science.gov (United States)

Kasim, Shahreen; Hafit, Hanayanti; Yee, Ng Peng; Hashim, Rathiah; Ruslai, Husni; Jahidin, Kamaruzzaman; Syafwan Arshad, Mohammad

2016-11-01

Crime Map is an online web based geographical information system that assists the public and users to visualize crime activities geographically. It acts as a platform for the public communities to share crime activities they encountered. Crime and violence plague the communities we are living in. As part of the community, crime prevention is everyone's responsibility. The purpose of Crime Map is to provide insights of the crimes occurring around Malaysia and raise the public's awareness on crime activities in their neighbourhood. For that, Crime Map visualizes crime activities on a geographical heat maps, generated based on geospatial data. Crime Map analyse data obtained from crime reports to generate useful information on crime trends. At the end of the development, users should be able to make use of the system to access to details of crime reported, crime analysis and report crimes activities. The development of Crime Map also enable the public to obtain insights about crime activities in their area. Thus, enabling the public to work together with the law enforcer to prevent and fight crime.

Short-Term Plasticity of the Visuomotor Map during Grasping Movements in Humans

Science.gov (United States)

Safstrom, Daniel; Edin, Benoni B.

2005-01-01

During visually guided grasping movements, visual information is transformed into motor commands. This transformation is known as the "visuomotor map." To investigate limitations in the short-term plasticity of the visuomotor map in normal humans, we studied the maximum grip aperture (MGA) during the reaching phase while subjects grasped objects…

Stereoscopic Visual Attention-Based Regional Bit Allocation Optimization for Multiview Video Coding

Directory of Open Access Journals (Sweden)

Dai Qionghai

2010-01-01

Full Text Available We propose a Stereoscopic Visual Attention- (SVA- based regional bit allocation optimization for Multiview Video Coding (MVC by the exploiting visual redundancies from human perceptions. We propose a novel SVA model, where multiple perceptual stimuli including depth, motion, intensity, color, and orientation contrast are utilized, to simulate the visual attention mechanisms of human visual system with stereoscopic perception. Then, a semantic region-of-interest (ROI is extracted based on the saliency maps of SVA. Both objective and subjective evaluations of extracted ROIs indicated that the proposed SVA model based on ROI extraction scheme outperforms the schemes only using spatial or/and temporal visual attention clues. Finally, by using the extracted SVA-based ROIs, a regional bit allocation optimization scheme is presented to allocate more bits on SVA-based ROIs for high image quality and fewer bits on background regions for efficient compression purpose. Experimental results on MVC show that the proposed regional bit allocation algorithm can achieve over % bit-rate saving while maintaining the subjective image quality. Meanwhile, the image quality of ROIs is improved by  dB at the cost of insensitive image quality degradation of the background image.

Body_Machine? Encounters of the Human and the Mechanical in Education, Industry and Science

Science.gov (United States)

Herman, Frederik; Priem, Karin; Thyssen, Geert

2017-01-01

This paper unveils the body_machine as a key element of dynamic mental maps that have come to shape both educational praxis and research. It traces and analyses instances in which the human and the mechanical encountered each other in metaphorical, material and visual forms, thereby blurring to some extent the boundaries between them while…

Quantification and visualization of carotid segmentation accuracy and precision using a 2D standardized carotid map

International Nuclear Information System (INIS)

Chiu, Bernard; Ukwatta, Eranga; Shavakh, Shadi; Fenster, Aaron

2013-01-01

This paper describes a framework for vascular image segmentation evaluation. Since the size of vessel wall and plaque burden is defined by the lumen and wall boundaries in vascular segmentation, these two boundaries should be considered as a pair in statistical evaluation of a segmentation algorithm. This work proposed statistical metrics to evaluate the difference of local vessel wall thickness (VWT) produced by manual and algorithm-based semi-automatic segmentation methods (ΔT) with the local segmentation standard deviation of the wall and lumen boundaries considered. ΔT was further approximately decomposed into the local wall and lumen boundary differences (ΔW and ΔL respectively) in order to provide information regarding which of the wall and lumen segmentation errors contribute more to the VWT difference. In this study, the lumen and wall boundaries in 3D carotid ultrasound images acquired for 21 subjects were each segmented five times manually and by a level-set segmentation algorithm. The (absolute) difference measures (i.e., ΔT, ΔW, ΔL and their absolute values) and the pooled local standard deviation of manually and algorithmically segmented wall and lumen boundaries were computed for each subject and represented in a 2D standardized map. The local accuracy and variability of the segmentation algorithm at each point can be quantified by the average of these metrics for the whole group of subjects and visualized on the 2D standardized map. Based on the results shown on the 2D standardized map, a variety of strategies, such as adding anchor points and adjusting weights of different forces in the algorithm, can be introduced to improve the accuracy and variability of the algorithm. (paper)

Perceptual maps: the good, the bad and the ugly

NARCIS (Netherlands)

J.C. Gower (John); P.J.F. Groenen (Patrick); M. van de Velden (Michel); K. Vines (Karen)

2010-01-01

textabstractPerceptual maps are often used in marketing to visually study relations between two or more attributes. However, in many perceptual maps published in the recent literature it remains unclear what is being shown and how the relations between the points in the map can be interpreted or

Spatio-Temporal Story Mapping Animation Based On Structured Causal Relationships Of Historical Events

Science.gov (United States)

Inoue, Y.; Tsuruoka, K.; Arikawa, M.

2014-04-01

In this paper, we proposed a user interface that displays visual animations on geographic maps and timelines for depicting historical stories by representing causal relationships among events for time series. We have been developing an experimental software system for the spatial-temporal visualization of historical stories for tablet computers. Our proposed system makes people effectively learn historical stories using visual animations based on hierarchical structures of different scale timelines and maps.

Spatial-area selective retrieval of multiple object-place associations in a hierarchical cognitive map formed by theta phase coding.

Science.gov (United States)

Sato, Naoyuki; Yamaguchi, Yoko

2009-06-01

The human cognitive map is known to be hierarchically organized consisting of a set of perceptually clustered landmarks. Patient studies have demonstrated that these cognitive maps are maintained by the hippocampus, while the neural dynamics are still poorly understood. The authors have shown that the neural dynamic "theta phase precession" observed in the rodent hippocampus may be capable of forming hierarchical cognitive maps in humans. In the model, a visual input sequence consisting of object and scene features in the central and peripheral visual fields, respectively, results in the formation of a hierarchical cognitive map for object-place associations. Surprisingly, it is possible for such a complex memory structure to be formed in a few seconds. In this paper, we evaluate the memory retrieval of object-place associations in the hierarchical network formed by theta phase precession. The results show that multiple object-place associations can be retrieved with the initial cue of a scene input. Importantly, according to the wide-to-narrow unidirectional connections among scene units, the spatial area for object-place retrieval can be controlled by the spatial area of the initial cue input. These results indicate that the hierarchical cognitive maps have computational advantages on a spatial-area selective retrieval of multiple object-place associations. Theta phase precession dynamics is suggested as a fundamental neural mechanism of the human cognitive map.

Creating visual explanations improves learning.

Science.gov (United States)

Bobek, Eliza; Tversky, Barbara

2016-01-01

Many topics in science are notoriously difficult for students to learn. Mechanisms and processes outside student experience present particular challenges. While instruction typically involves visualizations, students usually explain in words. Because visual explanations can show parts and processes of complex systems directly, creating them should have benefits beyond creating verbal explanations. We compared learning from creating visual or verbal explanations for two STEM domains, a mechanical system (bicycle pump) and a chemical system (bonding). Both kinds of explanations were analyzed for content and learning assess by a post-test. For the mechanical system, creating a visual explanation increased understanding particularly for participants of low spatial ability. For the chemical system, creating both visual and verbal explanations improved learning without new teaching. Creating a visual explanation was superior and benefitted participants of both high and low spatial ability. Visual explanations often included crucial yet invisible features. The greater effectiveness of visual explanations appears attributable to the checks they provide for completeness and coherence as well as to their roles as platforms for inference. The benefits should generalize to other domains like the social sciences, history, and archeology where important information can be visualized. Together, the findings provide support for the use of learner-generated visual explanations as a powerful learning tool.

A Lithology Based Map Unit Schema For Onegeology Regional Geologic Map Integration

Science.gov (United States)

Moosdorf, N.; Richard, S. M.

2012-12-01

A system of lithogenetic categories for a global lithological map (GLiM, http://www.ifbm.zmaw.de/index.php?id=6460&L=3) has been compiled based on analysis of lithology/genesis categories for regional geologic maps for the entire globe. The scheme is presented for discussion and comment. Analysis of units on a variety of regional geologic maps indicates that units are defined based on assemblages of rock types, as well as their genetic type. In this compilation of continental geology, outcropping surface materials are dominantly sediment/sedimentary rock; major subdivisions of the sedimentary category include clastic sediment, carbonate sedimentary rocks, clastic sedimentary rocks, mixed carbonate and clastic sedimentary rock, colluvium and residuum. Significant areas of mixed igneous and metamorphic rock are also present. A system of global categories to characterize the lithology of regional geologic units is important for Earth System models of matter fluxes to soils, ecosystems, rivers and oceans, and for regional analysis of Earth surface processes at global scale. Because different applications of the classification scheme will focus on different lithologic constituents in mixed units, an ontology-type representation of the scheme that assigns properties to the units in an analyzable manner will be pursued. The OneGeology project is promoting deployment of geologic map services at million scale for all nations. Although initial efforts are commonly simple scanned map WMS services, the intention is to move towards data-based map services that categorize map units with standard vocabularies to allow use of a common map legend for better visual integration of the maps (e.g. see OneGeology Europe, http://onegeology-europe.brgm.fr/ geoportal/ viewer.jsp). Current categorization of regional units with a single lithology from the CGI SimpleLithology (http://resource.geosciml.org/201202/ Vocab2012html/ SimpleLithology201012.html) vocabulary poorly captures the

Tensor SOM and tensor GTM: Nonlinear tensor analysis by topographic mappings.

Science.gov (United States)

Iwasaki, Tohru; Furukawa, Tetsuo

2016-05-01

In this paper, we propose nonlinear tensor analysis methods: the tensor self-organizing map (TSOM) and the tensor generative topographic mapping (TGTM). TSOM is a straightforward extension of the self-organizing map from high-dimensional data to tensorial data, and TGTM is an extension of the generative topographic map, which provides a theoretical background for TSOM using a probabilistic generative model. These methods are useful tools for analyzing and visualizing tensorial data, especially multimodal relational data. For given n-mode relational data, TSOM and TGTM can simultaneously organize a set of n-topographic maps. Furthermore, they can be used to explore the tensorial data space by interactively visualizing the relationships between modes. We present the TSOM algorithm and a theoretical description from the viewpoint of TGTM. Various TSOM variations and visualization techniques are also described, along with some applications to real relational datasets. Additionally, we attempt to build a comprehensive description of the TSOM family by adapting various data structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Visualizing Mortality Dynamics in the Lexis Diagram

DEFF Research Database (Denmark)

Rau, Roland; Bohk-Ewald, Christina; Muszynska, Magdalena M

This book visualizes mortality dynamics in the Lexis diagram. While the standard approach of plotting death rates is also covered, the focus in this book is on the depiction of rates of mortality improvement over age and time. This rather novel approach offers a more intuitive understanding...... of the underlying dynamics, enabling readers to better understand whether period- or cohort-effects were instrumental for the development of mortality in a particular country. Besides maps for single countries, the book includes maps on the dynamics of selected causes of death in the United States...... Software to produce these types of surface maps. Readers are encouraged to use the presented tools to visualize other demographic data or any event that can be measured by age and calendar time, allowing them to adapt the methods to their respective research interests. The intended audience is anyone who...

Visual attention in preterm born adults: specifically impaired attentional sub-mechanisms that link with altered intrinsic brain networks in a compensation-like mode.

Science.gov (United States)

Finke, Kathrin; Neitzel, Julia; Bäuml, Josef G; Redel, Petra; Müller, Hermann J; Meng, Chun; Jaekel, Julia; Daamen, Marcel; Scheef, Lukas; Busch, Barbara; Baumann, Nicole; Boecker, Henning; Bartmann, Peter; Habekost, Thomas; Wolke, Dieter; Wohlschläger, Afra; Sorg, Christian

2015-02-15

Although pronounced and lasting deficits in selective attention have been observed for preterm born individuals it is unknown which specific attentional sub-mechanisms are affected and how they relate to brain networks. We used the computationally specified 'Theory of Visual Attention' together with whole- and partial-report paradigms to compare attentional sub-mechanisms of pre- (n=33) and full-term (n=32) born adults. Resting-state fMRI was used to evaluate both between-group differences and inter-individual variance in changed functional connectivity of intrinsic brain networks relevant for visual attention. In preterm born adults, we found specific impairments of visual short-term memory (vSTM) storage capacity while other sub-mechanisms such as processing speed or attentional weighting were unchanged. Furthermore, changed functional connectivity was found in unimodal visual and supramodal attention-related intrinsic networks. Among preterm born adults, the individual pattern of changed connectivity in occipital and parietal cortices was systematically associated with vSTM in such a way that the more distinct the connectivity differences, the better the preterm adults' storage capacity. These findings provide first evidence for selectively changed attentional sub-mechanisms in preterm born adults and their relation to altered intrinsic brain networks. In particular, data suggest that cortical changes in intrinsic functional connectivity may compensate adverse developmental consequences of prematurity on visual short-term storage capacity. Copyright © 2014 Elsevier Inc. All rights reserved.

Degree of mapping for general relativistic kinks

International Nuclear Information System (INIS)

Harriot, Tina A.; Williams, J.G.

2005-01-01

The Finkelstein-Misner metrical kinks of general relativity are homo topically nontrivial light cone configurations that can occur on space-time hypersurfaces. The number of kinks corresponds to the winding number of a timelike vector field that that is determined from the metric. This paper uses the usual Euclidean integral formula for degree of mapping as a starting point and so produces a covariant formula that can be applied to counting general relativistic kinks in any dimension. The kink number is calculated for some simple-to-visualize examples in 2 + 1 dimensions. These include hypersurfaces of differing topologies and so have relevance to mechanisms of topology change in semi-classical theories of quantum gravity

The Visual System

Medline Plus

Full Text Available ... to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and requirements of the blind.” ... Clinical Studies Publications Catalog Photos ...

Recent Advances in Geospatial Visualization with the New Google Earth

Science.gov (United States)

Anderson, J. C.; Poyart, E.; Yan, S.; Sargent, R.

2017-12-01

Google Earth's detailed, world-wide imagery and terrain data provide a rich backdrop for geospatial visualization at multiple scales, from global to local. The Keyhole Markup Language (KML) is an open standard that has been the primary way for users to author and share data visualizations in Google Earth. Despite its ease of use and flexibility for relatively small amounts of data, users can quickly run into difficulties and limitations working with large-scale or time-varying datasets using KML in Google Earth. Recognizing these challenges, we present our recent work toward extending Google Earth to be a more powerful data visualization platform. We describe a new KML extension to simplify the display of multi-resolution map tile pyramids - which can be created by analysis platforms like Google Earth Engine, or by a variety of other map tile production pipelines. We also describe how this implementation can pave the way to creating novel data visualizations by leveraging custom graphics shaders. Finally, we present our investigations into native support in Google Earth for data storage and transport formats that are well-suited for big raster and vector data visualization. Taken together, these capabilities make it easier to create and share new scientific data visualization experiences using Google Earth, and simplify the integration of Google Earth with existing map data products, services, and analysis pipelines.

Visualization for genomics: the Microbial Genome Viewer.

Science.gov (United States)

Kerkhoven, Robert; van Enckevort, Frank H J; Boekhorst, Jos; Molenaar, Douwe; Siezen, Roland J

2004-07-22

A Web-based visualization tool, the Microbial Genome Viewer, is presented that allows the user to combine complex genomic data in a highly interactive way. This Web tool enables the interactive generation of chromosome wheels and linear genome maps from genome annotation data stored in a MySQL database. The generated images are in scalable vector graphics (SVG) format, which is suitable for creating high-quality scalable images and dynamic Web representations. Gene-related data such as transcriptome and time-course microarray experiments can be superimposed on the maps for visual inspection. The Microbial Genome Viewer 1.0 is freely available at http://www.cmbi.kun.nl/MGV

Visual perception and consciousness in dermatopathology: mechanisms of figure-ground segregation account for errors in diagnosis.

Science.gov (United States)

Böer, Almut

2009-02-01

Visual perception has been the object of research in psychology for almost a century. Little has been written, however, about the effects of perceptive phenomena on methods in medicine that utilize interpretation of two-dimensional images for diagnosis. Starting from the work by Edgar Rubin in the beginning of the last century, this article gives a summary of observations of psychologists who investigated the mechanisms of so-called "figure-ground segregation." These unconscious mechanisms follow rules that explain why certain structures are perceived consciously as a figure, whereas other structures surrounding such a figure are neglected and not perceived consciously in detail. Perception of a structure as a figure can be due to, for example, a convex shape of its contour, proximity of lines around it, closed contours, a simple shape, and attribution of meaning to a structure. In examples from the practice of dermatopathology, those unconscious mechanisms of figure-ground segregation will be shown to be relevant to diagnosis of sections of tissue. The mechanisms help to explain why, for example, ill-defined and concave-shaped structures, stromal differences of neoplasms, interstitial infiltrates and deposits, and simulators of common diseases are often difficult to recognize at first sight. Teachers of dermatopathology need to be aware of these unconscious mechanisms of visual perception because they explain why novices struggle with certain diagnoses and differential diagnoses. Proper instruction about these phenomena, early in the process of training, will prevent a student from being frustrated with misperceptions.

Using Technology to Support Visual Learning Strategies

Science.gov (United States)

O'Bannon, Blanche; Puckett, Kathleen; Rakes, Glenda

2006-01-01

Visual learning is a strategy for visually representing the structure of information and for representing the ways in which concepts are related. Based on the work of Ausubel, these hierarchical maps facilitate student learning of unfamiliar information in the K-12 classroom. This paper presents the research base for this Type II computer tool, as…

[MapDraw: a microsoft excel macro for drawing genetic linkage maps based on given genetic linkage data].

Science.gov (United States)

Liu, Ren-Hu; Meng, Jin-Ling

2003-05-01

MAPMAKER is one of the most widely used computer software package for constructing genetic linkage maps.However, the PC version, MAPMAKER 3.0 for PC, could not draw the genetic linkage maps that its Macintosh version, MAPMAKER 3.0 for Macintosh,was able to do. Especially in recent years, Macintosh computer is much less popular than PC. Most of the geneticists use PC to analyze their genetic linkage data. So a new computer software to draw the same genetic linkage maps on PC as the MAPMAKER for Macintosh to do on Macintosh has been crying for. Microsoft Excel,one component of Microsoft Office package, is one of the most popular software in laboratory data processing. Microsoft Visual Basic for Applications (VBA) is one of the most powerful functions of Microsoft Excel. Using this program language, we can take creative control of Excel, including genetic linkage map construction, automatic data processing and more. In this paper, a Microsoft Excel macro called MapDraw is constructed to draw genetic linkage maps on PC computer based on given genetic linkage data. Use this software,you can freely construct beautiful genetic linkage map in Excel and freely edit and copy it to Word or other application. This software is just an Excel format file. You can freely copy it from ftp://211.69.140.177 or ftp://brassica.hzau.edu.cn and the source code can be found in Excel's Visual Basic Editor.

NaviCell: a web-based environment for navigation, curation and maintenance of large molecular interaction maps.

Science.gov (United States)

Kuperstein, Inna; Cohen, David P A; Pook, Stuart; Viara, Eric; Calzone, Laurence; Barillot, Emmanuel; Zinovyev, Andrei

2013-10-07

Molecular biology knowledge can be formalized and systematically represented in a computer-readable form as a comprehensive map of molecular interactions. There exist an increasing number of maps of molecular interactions containing detailed and step-wise description of various cell mechanisms. It is difficult to explore these large maps, to organize discussion of their content and to maintain them. Several efforts were recently made to combine these capabilities together in one environment, and NaviCell is one of them. NaviCell is a web-based environment for exploiting large maps of molecular interactions, created in CellDesigner, allowing their easy exploration, curation and maintenance. It is characterized by a combination of three essential features: (1) efficient map browsing based on Google Maps; (2) semantic zooming for viewing different levels of details or of abstraction of the map and (3) integrated web-based blog for collecting community feedback. NaviCell can be easily used by experts in the field of molecular biology for studying molecular entities of interest in the context of signaling pathways and crosstalk between pathways within a global signaling network. NaviCell allows both exploration of detailed molecular mechanisms represented on the map and a more abstract view of the map up to a top-level modular representation. NaviCell greatly facilitates curation, maintenance and updating the comprehensive maps of molecular interactions in an interactive and user-friendly fashion due to an imbedded blogging system. NaviCell provides user-friendly exploration of large-scale maps of molecular interactions, thanks to Google Maps and WordPress interfaces, with which many users are already familiar. Semantic zooming which is used for navigating geographical maps is adopted for molecular maps in NaviCell, making any level of visualization readable. In addition, NaviCell provides a framework for community-based curation of maps.

Walkable self-overlapping virtual reality maze and map visualization demo

DEFF Research Database (Denmark)

Serubugo, Sule; Skantarova, Denisa; Evers, Nicolaj

2017-01-01

This paper describes our demonstration of a walkable self-overlapping maze and its corresponding map to facilitate asymmetric collaboration for room-scale virtual reality setups in public places.......This paper describes our demonstration of a walkable self-overlapping maze and its corresponding map to facilitate asymmetric collaboration for room-scale virtual reality setups in public places....

Mapping functional connectivity

Science.gov (United States)

Peter Vogt; Joseph R. Ferrari; Todd R. Lookingbill; Robert H. Gardner; Kurt H. Riitters; Katarzyna Ostapowicz

2009-01-01

An objective and reliable assessment of wildlife movement is important in theoretical and applied ecology. The identification and mapping of landscape elements that may enhance functional connectivity is usually a subjective process based on visual interpretations of species movement patterns. New methods based on mathematical morphology provide a generic, flexible,...

Data visualizations and infographics

CERN Document Server

Mauldin, Sarah K C

2015-01-01

Graphics which visually represent data or complex ideas are oftentimes easier for people to understand and digest than standalone statistics. A map shaded with different colors to represent religious affiliations or income levels enables researchers to quickly identify trends and patterns. New free tools and applications offer librarians the opportunity to organize and manipulate data to quickly create these helpful graphics. Learn how to overlay data sets on maps, create infographics for library services and instruction, use mindmapping for group brainstorming sessions, produce de

Interactive map of refugee movement in Europe

Directory of Open Access Journals (Sweden)

Calka Beata

2016-12-01

Full Text Available Considering the recent mass movement of people fleeing war and oppression, an analysis of changes in migration, in particular an analysis of the final destination refugees choose, seems to be of utmost importance. Many international organisations like UNHCR (the United Nations High Commissioner for Refugees or EuroStat gather and provide information on the number of refugees and the routes they follow. What is also needed to study the state of affairs closely is a visual form presenting the rapidly changing situation. An analysis of the problem together with up-to-date statistical data presented in the visual form of a map is essential. This article describes methods of preparing such interactive maps displaying movement of refugees in European Union countries. Those maps would show changes taking place throughout recent years but also the dynamics of the development of the refugee crisis in Europe. The ArcGIS software was applied to make the map accessible on the Internet. Additionally, online sources and newspaper articles were used to present the movement of migrants. The interactive map makes it possible to watch spatial data with an opportunity to navigate within the map window. Because of that it is a clear and convenient tool to visualise such processes as refugee migration in Europe.

Interactive map of refugee movement in Europe

Science.gov (United States)

Calka, Beata; Cahan, Bruce

2016-12-01

Considering the recent mass movement of people fleeing war and oppression, an analysis of changes in migration, in particular an analysis of the final destination refugees choose, seems to be of utmost importance. Many international organisations like UNHCR (the United Nations High Commissioner for Refugees) or EuroStat gather and provide information on the number of refugees and the routes they follow. What is also needed to study the state of affairs closely is a visual form presenting the rapidly changing situation. An analysis of the problem together with up-to-date statistical data presented in the visual form of a map is essential. This article describes methods of preparing such interactive maps displaying movement of refugees in European Union countries. Those maps would show changes taking place throughout recent years but also the dynamics of the development of the refugee crisis in Europe. The ArcGIS software was applied to make the map accessible on the Internet. Additionally, online sources and newspaper articles were used to present the movement of migrants. The interactive map makes it possible to watch spatial data with an opportunity to navigate within the map window. Because of that it is a clear and convenient tool to visualise such processes as refugee migration in Europe.

Pemanfaatan Google Maps Api Untuk Visualisasi Data Base Transceiver Station

OpenAIRE

Rani, Septia

2016-01-01

This paper discusses the use of the Google Maps API to perform data visualization for Base Transceiver Station (BTS) data. BTS are typically used by telecommunications companies to facilitate wireless communication between communication devices with the network operator. Each BTS has important information such as it's location, it's transaction traffic, as well as information about revenue. With the implementation of BTS data visualization using the Google Maps API, key information owned by e...

PEMANFAATAN GOOGLE MAPS API UNTUK VISUALISASI DATA BASE TRANSCEIVER STATION

OpenAIRE

Rani, Septia

2016-01-01

This paper discusses the use of the Google Maps API to perform data visualization for Base Transceiver Station (BTS) data. BTS are typically used by telecommunications companies to facilitate wireless communication between communication devices with the network operator. Each BTS has important information such as it’s location, it’s transaction traffic, as well as information about revenue. With the implementation of BTS data visualization using the Google Maps API, key information owned by e...

Pemanfaatan Google Maps Api Untuk Visualisasi Data Base Transceiver Station

OpenAIRE

Rani, Septia

2016-01-01

This paper discusses the use of the Google Maps API to perform data visualization for Base Transceiver Station (BTS) data. BTS are typically used by telecommunications companies to facilitate wireless communication between communication devices with the network operator. Each BTS has important information such as it’s location, it’s transaction traffic, as well as information about revenue. With the implementation of BTS data visualization using the Google Maps API, key information owned by e...

A Preliminary Study on the Use of Mind Mapping as a Visual-Learning Strategy in General Education Science Classes for Arabic Speakers in the United Arab Emirates

Science.gov (United States)

Wilson, Kenesha; Copeland-Solas, Eddia; Guthrie-Dixon, Natalie

2016-01-01

Mind mapping was introduced as a culturally relevant pedagogy aimed at enhancing the teaching and learning experience in a general education, Environmental Science class for mostly Emirati English Language Learners (ELL). Anecdotal evidence suggests that the students are very artistic and visual and enjoy group-based activities. It was decided to…

Assessment of the visual landscape impact and dominance of wind tubines in Austria using weighted viewshed maps

Science.gov (United States)

Schauppenlehner, Thomas; Salak, Boris; Scherhaufer, Patrick; Höltinger, Stefan; Schmidt, Johannes

2017-04-01

Due to efficiency reasons and broadly availability of wind, wind energy is in focus of strategies regarding the expansion of renewable energy and energy transition policies. Nevertheless, the dimensions of the wind turbines and rotating dynamics have a significant impact on the landscape scenery and recreation as well as tourism activities. This often leads to local opposition against wind energy projects and is a major criterion regarding the acceptance of wind energy. In the project TransWind, the social acceptance of wind energy is surveyed on the basis of different development scenarios for Austria. Therefore, a GIS-based viewshed indicator was developed to assess the visual impact of different development scenarios as well as the current situation using weighted - regarding distance, amount and masking - viewshed analysis. This weighted viewshed maps for Austria allows a comprehensive evaluation of existing and potential wind energy sites regarding dominance and visual impact and can contribute to the spatial development process of wind energy site. Different regions can be compared and repowering strategies can be evaluated. Due to the large project area, data resolutions, generalized assumptions (e.g. tree heights) and missing data (e.g. solitary trees, small hedges) at local level further analysis are necessary but it supports the assessment of large-scale development scenarios can be identified.

Two-dimensional Value Stream Mapping: Integrating the design of the MPC system in the value stream map

DEFF Research Database (Denmark)

Powell, Daryl; Olesen, Peter Bjerg

2013-01-01

Companies use value stream mapping to identify waste, often in the early stages of a lean implementation. Though the tool helps users to visualize material and information flows and to identify improvement opportunities, a limitation of this approach is the lack of an integrated method...... for analysing and re-designing the MPC system in order to support lean improvement. We reflect on the current literature regarding value stream mapping, and use practical insights in order to develop and propose a two-dimensional value stream mapping tool that integrates the design of the MPC system within...... the material and information flow map....

Metabolic mapping of the brain's response to visual stimulation: studies in humans

International Nuclear Information System (INIS)

Phelps, M.E.; Kuhl, D.E.; Mazziotta, J.C.

1981-01-01

These studies demonstrated increasing glucose metabolic rates in the human primary (PVC) and associative (AVC) visual cortex as the complexity of visual scenes increased. The metabolic response of the AVC increased more rapidly with scene complexity than that of the PVC, indicating the greater involvement of the higher order AVC for complex visual interpretations. Increases in local metabolic activity by as much as a factor of 2 above that of control subjects with eyes closed indicate the wide range and metabolic reserve of the visual cortex

Evolution and mechanism of spectral tuning of blue-absorbing visual pigments in butterflies.

Directory of Open Access Journals (Sweden)

Motohiro Wakakuwa

Full Text Available The eyes of flower-visiting butterflies are often spectrally highly complex with multiple opsin genes generated by gene duplication, providing an interesting system for a comparative study of color vision. The Small White butterfly, Pieris rapae, has duplicated blue opsins, PrB and PrV, which are expressed in the blue (λ(max = 453 nm and violet receptors (λ(max = 425 nm, respectively. To reveal accurate absorption profiles and the molecular basis of the spectral tuning of these visual pigments, we successfully modified our honeybee opsin expression system based on HEK293s cells, and expressed PrB and PrV, the first lepidopteran opsins ever expressed in cultured cells. We reconstituted the expressed visual pigments in vitro, and analysed them spectroscopically. Both reconstituted visual pigments had two photointerconvertible states, rhodopsin and metarhodopsin, with absorption peak wavelengths 450 nm and 485 nm for PrB and 420 nm and 482 nm for PrV. We furthermore introduced site-directed mutations to the opsins and found that two amino acid substitutions, at positions 116 and 177, were crucial for the spectral tuning. This tuning mechanism appears to be specific for invertebrates and is partially shared by other pierid and lycaenid butterfly species.

Basic mapping principles for visualizing cancer data using Geographic Information Systems (GIS).

Science.gov (United States)

Brewer, Cynthia A

2006-02-01

Maps and other data graphics may play a role in generating ideas and hypotheses at the beginning of a project. They are useful as part of analyses for evaluating model results and then at the end of a project when researchers present their results and conclusions to varied audiences, such as their local research group, decision makers, or a concerned public. Cancer researchers are gaining skill with geographic information system (GIS) mapping as one of their many tools and are broadening the symbolization approaches they use for investigating and illustrating their data. A single map is one of many possible representations of the data, so making multiple maps is often part of a complete mapping effort. Symbol types, color choices, and data classing each affect the information revealed by a map and are best tailored to the specific characteristics of data. Related data can be examined in series with coordinated classing and can also be compared using multivariate symbols that build on the basic rules of symbol design. Informative legend wording and setting suitable map projections are also basic to skilled mapmaking.

Sandwich masking eliminates both visual awareness of faces and face-specific brain activity through a feedforward mechanism.

Science.gov (United States)

Harris, Joseph A; Wu, Chien-Te; Woldorff, Marty G

2011-06-07

It is generally agreed that considerable amounts of low-level sensory processing of visual stimuli can occur without conscious awareness. On the other hand, the degree of higher level visual processing that occurs in the absence of awareness is as yet unclear. Here, event-related potential (ERP) measures of brain activity were recorded during a sandwich-masking paradigm, a commonly used approach for attenuating conscious awareness of visual stimulus content. In particular, the present study used a combination of ERP activation contrasts to track both early sensory-processing ERP components and face-specific N170 ERP activations, in trials with versus without awareness. The electrophysiological measures revealed that the sandwich masking abolished the early face-specific N170 neural response (peaking at ~170 ms post-stimulus), an effect that paralleled the abolition of awareness of face versus non-face image content. Furthermore, however, the masking appeared to render a strong attenuation of earlier feedforward visual sensory-processing signals. This early attenuation presumably resulted in insufficient information being fed into the higher level visual system pathways specific to object category processing, thus leading to unawareness of the visual object content. These results support a coupling of visual awareness and neural indices of face processing, while also demonstrating an early low-level mechanism of interference in sandwich masking.

Novel Scientific Visualization Interfaces for Interactive Information Visualization and Sharing

Science.gov (United States)

Demir, I.; Krajewski, W. F.

2012-12-01

As geoscientists are confronted with increasingly massive datasets from environmental observations to simulations, one of the biggest challenges is having the right tools to gain scientific insight from the data and communicate the understanding to stakeholders. Recent developments in web technologies make it easy to manage, visualize and share large data sets with general public. Novel visualization techniques and dynamic user interfaces allow users to interact with data, and modify the parameters to create custom views of the data to gain insight from simulations and environmental observations. This requires developing new data models and intelligent knowledge discovery techniques to explore and extract information from complex computational simulations or large data repositories. Scientific visualization will be an increasingly important component to build comprehensive environmental information platforms. This presentation provides an overview of the trends and challenges in the field of scientific visualization, and demonstrates information visualization and communication tools in the Iowa Flood Information System (IFIS), developed within the light of these challenges. The IFIS is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to and visualization of flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, and other flood-related data for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and

An 00 visual language definition approach supporting multiple views

OpenAIRE

Akehurst, David H.; I.E.E.E. Computer Society

2000-01-01

The formal approach to visual language definition is to use graph grammars and/or graph transformation techniques. These techniques focus on specifying the syntax and manipulation rules of the concrete representation. This paper presents a constraint and object-oriented approach to defining visual languages that uses UML and OCL as a definition language. Visual language definitions specify a mapping between concrete and abstract models of possible visual sentences, which carl subsequently be ...

Mapping Large-Scale Mechanized Agriculture Across the Brazilian Cerrado Between 2001-2013

Science.gov (United States)

Spera, S. A.; Mustard, J. F.; VanWey, L.

2014-12-01

Brazil is a global commodities powerhouse. Over the last decade, dynamic changes in agricultural development and land transformations occurred within Brazil's tropical savanna region, the cerrado. This interdisciplinary study uses remote sensing tools to map land cover across more than 3.6 million km2 of cerrado and statistical methods to characterize drivers of this land-cover change. We use the MODIS Enhanced Vegetation Index 16-day data product and a decision-tree algorithm, proven highly accurate in Mato Grosso (Spera et al. 2014) and here modified for the broader cerrado region, to characterize crop type, cropping frequency, expansion, and abandonment of large-scale mechanized agriculture during the 2001-2013 period. The algorithm exploits phenological differences between forest, pasture and cerrado, and mechanized agriculture. It is parameterized to distinguish between crop rotations in Mato Grosso, Goias, and the new agricultural frontier spanning Maranhao, Tocantins, Piaui, and Bahia (MaToPiBa). Training and validation data were collected using Google's Earth Engine. We map single-cropped soy, corn, and cotton; double-cropped soy/corn and soy/cotton rotations; and irrigated agriculture across these six Brazilian cerrado states. We find that while double cropping dominates in Mato Grosso and Goias, single cropping is still the dominant form of mechanized agriculture in the burgeoning MaToPiBa region. In western Bahia alone, preliminary results show agriculture has expanded by almost 350,000 ha and double cropping has increased by almost 40,000 ha. With MaToPiBa touted as Brazil's latest and last agricultural frontier, we predict that the region will experience a transition similar to that of Mato Grosso during the 2000s—an expansion and intensification of agriculture—which may beget unprecedented ramifications on regional climate processes that can then affect ecosystem health and the economic feasibility of cultivating rain-fed export crops.

ORGANIZATION AND VISUALIZATION TO OBSERVATIONAL DATA USING WEB MAPPING SERVICES

Directory of Open Access Journals (Sweden)

A. A. Kadochnikov

2014-01-01

Full Text Available Current trends in the field of nature protection are monitoring environmental pollution resulting from human impact on nature, and as a result of natural processes. Monitoring the state of the environment in the area of the various industries can reduce costs to eliminate the impact of industrial accidents, which in turn reduces the possibility of contamination soil, surface water, loss of vegetation and wildlife. Consider the problem of creation of information-analytical systems for environmental monitoring of the natural environment and resources, built on the basis of GIS technologies, Internet, remote sensing data processing and data from monitoring stations. Considerable attention is given to web services, software interfaces and generally accepted standards. The author were directly involved in the development and implementation of projects of ecological orientation. In developing the software many different software libraries and components were used. Web mapping user interface was created using a number of open source libraries. To create a server-side web application author used GIS platforms MapGuide Open Source and Minnesota MapServer. GeoWebCache was another essential component of distributed web mapping environmental monitoring applications.

Integrating Spherical Panoramas and Maps for Visualization of Cultural Heritage Objects Using Virtual Reality Technology.

Science.gov (United States)

Koeva, Mila; Luleva, Mila; Maldjanski, Plamen

2017-04-11

Development and virtual representation of 3D models of Cultural Heritage (CH) objects has triggered great interest over the past decade. The main reason for this is the rapid development in the fields of photogrammetry and remote sensing, laser scanning, and computer vision. The advantages of using 3D models for restoration, preservation, and documentation of valuable historical and architectural objects have been numerously demonstrated by scientists in the field. Moreover, 3D model visualization in virtual reality has been recognized as an efficient, fast, and easy way of representing a variety of objects worldwide for present-day users, who have stringent requirements and high expectations. However, the main focus of recent research is the visual, geometric, and textural characteristics of a single concrete object, while integration of large numbers of models with additional information-such as historical overview, detailed description, and location-are missing. Such integrated information can be beneficial, not only for tourism but also for accurate documentation. For that reason, we demonstrate in this paper an integration of high-resolution spherical panoramas, a variety of maps, GNSS, sound, video, and text information for representation of numerous cultural heritage objects. These are then displayed in a web-based portal with an intuitive interface. The users have the opportunity to choose freely from the provided information, and decide for themselves what is interesting to visit. Based on the created web application, we provide suggestions and guidelines for similar studies. We selected objects, which are located in Bulgaria-a country with thousands of years of history and cultural heritage dating back to ancient civilizations. The methods used in this research are applicable for any type of spherical or cylindrical images and can be easily followed and applied in various domains. After a visual and metric assessment of the panoramas and the evaluation of

Practical indoor mobile robot navigation using hybrid maps

DEFF Research Database (Denmark)

Özkil, Ali Gürcan; Fan, Zhun; Xiao, Jizhong

2011-01-01

This paper presents a practical navigation scheme for indoor mobile robots using hybrid maps. The method makes use of metric maps for local navigation and a topological map for global path planning. Metric maps are generated as 2D occupancy grids by a range sensor to represent local information...... about partial areas. The global topological map is used to indicate the connectivity of the 'places-of-interests' in the environment and the interconnectivity of the local maps. Visual tags on the ceiling to be detected by the robot provide valuable information and contribute to reliable localization...... robot and evaluated in a hospital environment....

A neural mechanism of dynamic gating of task-relevant information by top-down influence in primary visual cortex.

Science.gov (United States)

Kamiyama, Akikazu; Fujita, Kazuhisa; Kashimori, Yoshiki

2016-12-01

Visual recognition involves bidirectional information flow, which consists of bottom-up information coding from retina and top-down information coding from higher visual areas. Recent studies have demonstrated the involvement of early visual areas such as primary visual area (V1) in recognition and memory formation. V1 neurons are not passive transformers of sensory inputs but work as adaptive processor, changing their function according to behavioral context. Top-down signals affect tuning property of V1 neurons and contribute to the gating of sensory information relevant to behavior. However, little is known about the neuronal mechanism underlying the gating of task-relevant information in V1. To address this issue, we focus on task-dependent tuning modulations of V1 neurons in two tasks of perceptual learning. We develop a model of the V1, which receives feedforward input from lateral geniculate nucleus and top-down input from a higher visual area. We show here that the change in a balance between excitation and inhibition in V1 connectivity is necessary for gating task-relevant information in V1. The balance change well accounts for the modulations of tuning characteristic and temporal properties of V1 neuronal responses. We also show that the balance change of V1 connectivity is shaped by top-down signals with temporal correlations reflecting the perceptual strategies of the two tasks. We propose a learning mechanism by which synaptic balance is modulated. To conclude, top-down signal changes the synaptic balance between excitation and inhibition in V1 connectivity, enabling early visual area such as V1 to gate context-dependent information under multiple task performances. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Visual System

Medline Plus

Full Text Available ... National Eye Institute’s mission is to “conduct and support research, training, health information dissemination, and other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, ...

Words, Shape, Visual Search and Visual Working Memory in 3-Year-Old Children

Science.gov (United States)

Vales, Catarina; Smith, Linda B.

2015-01-01

Do words cue children's visual attention, and if so, what are the relevant mechanisms? Across four experiments, 3-year-old children (N = 163) were tested in visual search tasks in which targets were cued with only a visual preview versus a visual preview and a spoken name. The experiments were designed to determine whether labels facilitated…

The Computational Anatomy of Visual Neglect.

Science.gov (United States)

Parr, Thomas; Friston, Karl J

2018-02-01

Visual neglect is a debilitating neuropsychological phenomenon that has many clinical implications and-in cognitive neuroscience-offers an important lesion deficit model. In this article, we describe a computational model of visual neglect based upon active inference. Our objective is to establish a computational and neurophysiological process theory that can be used to disambiguate among the various causes of this important syndrome; namely, a computational neuropsychology of visual neglect. We introduce a Bayes optimal model based upon Markov decision processes that reproduces the visual searches induced by the line cancellation task (used to characterize visual neglect at the bedside). We then consider 3 distinct ways in which the model could be lesioned to reproduce neuropsychological (visual search) deficits. Crucially, these 3 levels of pathology map nicely onto the neuroanatomy of saccadic eye movements and the systems implicated in visual neglect. © The Author 2017. Published by Oxford University Press.

The Visual System

Medline Plus

Full Text Available ... NIH), the National Eye Institute’s mission is to “conduct and support research, training, health information dissemination, and other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of ...

Science Mapping: A Systematic Review of the Literature

Directory of Open Access Journals (Sweden)

Chaomei Chen

2017-03-01

Full Text Available Purpose: We present a systematic review of the literature concerning major aspects of science mapping to serve two primary purposes: First, to demonstrate the use of a science mapping approach to perform the review so that researchers may apply the procedure to the review of a scientific domain of their own interest, and second, to identify major areas of research activities concerning science mapping, intellectual milestones in the development of key specialties, evolutionary stages of major specialties involved, and the dynamics of transitions from one specialty to another. Design/methodology/approach: We first introduce a theoretical framework of the evolution of a scientific specialty. Then we demonstrate a generic search strategy that can be used to construct a representative dataset of bibliographic records of a domain of research. Next, progressively synthesized co-citation networks are constructed and visualized to aid visual analytic studies of the domain’s structural and dynamic patterns and trends. Finally, trajectories of citations made by particular types of authors and articles are presented to illustrate the predictive potential of the analytic approach. Findings: The evolution of the science mapping research involves the development of a number of interrelated specialties. Four major specialties are discussed in detail in terms of four evolutionary stages: conceptualization, tool construction, application, and codification. Underlying connections between major specialties are also explored. The predictive analysis demonstrates citations trajectories of potentially transformative contributions. Research limitations: The systematic review is primarily guided by citation patterns in the dataset retrieved from the literature. The scope of the data is limited by the source of the retrieval, i.e. the Web of Science, and the composite query used. An iterative query refinement is possible if one would like to improve the data quality

Vizic: A Jupyter-based interactive visualization tool for astronomical catalogs

Science.gov (United States)

Yu, W.; Carrasco Kind, M.; Brunner, R. J.

2017-07-01

The ever-growing datasets in observational astronomy have challenged scientists in many aspects, including an efficient and interactive data exploration and visualization. Many tools have been developed to confront this challenge. However, they usually focus on displaying the actual images or focus on visualizing patterns within catalogs in a predefined way. In this paper we introduce Vizic, a Python visualization library that builds the connection between images and catalogs through an interactive map of the sky region. Vizic visualizes catalog data over a custom background canvas using the shape, size and orientation of each object in the catalog. The displayed objects in the map are highly interactive and customizable comparing to those in the observation images. These objects can be filtered by or colored by their property values, such as redshift and magnitude. They also can be sub-selected using a lasso-like tool for further analysis using standard Python functions and everything is done from inside a Jupyter notebook. Furthermore, Vizic allows custom overlays to be appended dynamically on top of the sky map. We have initially implemented several overlays, namely, Voronoi, Delaunay, Minimum Spanning Tree and HEALPix grid layer, which are helpful for visualizing large-scale structure. All these overlays can be generated, added or removed interactively with just one line of code. The catalog data is stored in a non-relational database, and the interfaces have been developed in JavaScript and Python to work within Jupyter Notebook, which allows to create customizable widgets, user generated scripts to analyze and plot the data selected/displayed in the interactive map. This unique design makes Vizic a very powerful and flexible interactive analysis tool. Vizic can be adopted in variety of exercises, for example, data inspection, clustering analysis, galaxy alignment studies, outlier identification or just large scale visualizations.

Genetic fine-mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci

Science.gov (United States)

Mahajan, Anubha; Locke, Adam; Rayner, N William; Robertson, Neil; Scott, Robert A; Prokopenko, Inga; Scott, Laura J; Green, Todd; Sparso, Thomas; Thuillier, Dorothee; Yengo, Loic; Grallert, Harald; Wahl, Simone; Frånberg, Mattias; Strawbridge, Rona J; Kestler, Hans; Chheda, Himanshu; Eisele, Lewin; Gustafsson, Stefan; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Qi, Lu; Karssen, Lennart C; van Leeuwen, Elisabeth M; Willems, Sara M; Li, Man; Chen, Han; Fuchsberger, Christian; Kwan, Phoenix; Ma, Clement; Linderman, Michael; Lu, Yingchang; Thomsen, Soren K; Rundle, Jana K; Beer, Nicola L; van de Bunt, Martijn; Chalisey, Anil; Kang, Hyun Min; Voight, Benjamin F; Abecasis, Goncalo R; Almgren, Peter; Baldassarre, Damiano; Balkau, Beverley; Benediktsson, Rafn; Blüher, Matthias; Boeing, Heiner; Bonnycastle, Lori L; Borringer, Erwin P; Burtt, Noël P; Carey, Jason; Charpentier, Guillaume; Chines, Peter S; Cornelis, Marilyn C; Couper, David J; Crenshaw, Andrew T; van Dam, Rob M; Doney, Alex SF; Dorkhan, Mozhgan; Edkins, Sarah; Eriksson, Johan G; Esko, Tonu; Eury, Elodie; Fadista, João; Flannick, Jason; Fontanillas, Pierre; Fox, Caroline; Franks, Paul W; Gertow, Karl; Gieger, Christian; Gigante, Bruna; Gottesman, Omri; Grant, George B; Grarup, Niels; Groves, Christopher J; Hassinen, Maija; Have, Christian T; Herder, Christian; Holmen, Oddgeir L; Hreidarsson, Astradur B; Humphries, Steve E; Hunter, David J; Jackson, Anne U; Jonsson, Anna; Jørgensen, Marit E; Jørgensen, Torben; Kerrison, Nicola D; Kinnunen, Leena; Klopp, Norman; Kong, Augustine; Kovacs, Peter; Kraft, Peter; Kravic, Jasmina; Langford, Cordelia; Leander, Karin; Liang, Liming; Lichtner, Peter; Lindgren, Cecilia M; Lindholm, Eero; Linneberg, Allan; Liu, Ching-Ti; Lobbens, Stéphane; Luan, Jian’an; Lyssenko, Valeriya; Männistö, Satu; McLeod, Olga; Meyer, Julia; Mihailov, Evelin; Mirza, Ghazala; Mühleisen, Thomas W; Müller-Nurasyid, Martina; Navarro, Carmen; Nöthen, Markus M; Oskolkov, Nikolay N; Owen, Katharine R; Palli, Domenico; Pechlivanis, Sonali; Perry, John RB; Platou, Carl GP; Roden, Michael; Ruderfer, Douglas; Rybin, Denis; van der Schouw, Yvonne T; Sennblad, Bengt; Sigurðsson, Gunnar; Stančáková, Alena; Steinbach, Gerald; Storm, Petter; Strauch, Konstantin; Stringham, Heather M; Sun, Qi; Thorand, Barbara; Tikkanen, Emmi; Tonjes, Anke; Trakalo, Joseph; Tremoli, Elena; Tuomi, Tiinamaija; Wennauer, Roman; Wood, Andrew R; Zeggini, Eleftheria; Dunham, Ian; Birney, Ewan; Pasquali, Lorenzo; Ferrer, Jorge; Loos, Ruth JF; Dupuis, Josée; Florez, Jose C; Boerwinkle, Eric; Pankow, James S; van Duijn, Cornelia; Sijbrands, Eric; Meigs, James B; Hu, Frank B; Thorsteinsdottir, Unnur; Stefansson, Kari; Lakka, Timo A; Rauramaa, Rainer; Stumvoll, Michael; Pedersen, Nancy L; Lind, Lars; Keinanen-Kiukaanniemi, Sirkka M; Korpi-Hyövälti, Eeva; Saaristo, Timo E; Saltevo, Juha; Kuusisto, Johanna; Laakso, Markku; Metspalu, Andres; Erbel, Raimund; Jöckel, Karl-Heinz; Moebus, Susanne; Ripatti, Samuli; Salomaa, Veikko; Ingelsson, Erik; Boehm, Bernhard O; Bergman, Richard N; Collins, Francis S; Mohlke, Karen L; Koistinen, Heikki; Tuomilehto, Jaakko; Hveem, Kristian; Njølstad, Inger; Deloukas, Panagiotis; Donnelly, Peter J; Frayling, Timothy M; Hattersley, Andrew T; de Faire, Ulf; Hamsten, Anders; Illig, Thomas; Peters, Annette; Cauchi, Stephane; Sladek, Rob; Froguel, Philippe; Hansen, Torben; Pedersen, Oluf; Morris, Andrew D; Palmer, Collin NA; Kathiresan, Sekar; Melander, Olle; Nilsson, Peter M; Groop, Leif C; Barroso, Inês; Langenberg, Claudia; Wareham, Nicholas J; O’Callaghan, Christopher A; Gloyn, Anna L; Altshuler, David; Boehnke, Michael; Teslovich, Tanya M; McCarthy, Mark I; Morris, Andrew P

2015-01-01

We performed fine-mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in/near KCNQ1. “Credible sets” of variants most likely to drive each distinct signal mapped predominantly to non-coding sequence, implying that T2D association is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine-mapping implicated rs10830963 as driving T2D association. We confirmed that this T2D-risk allele increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D-risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease. PMID:26551672

The Psychological Four-Color Mapping Problem

Science.gov (United States)

Francis, Gregory; Bias, Keri; Shive, Joshua

2010-01-01

Mathematicians have proven that four colors are sufficient to color 2-D maps so that no neighboring regions share the same color. Here we consider the psychological 4-color problem: Identifying which 4 colors should be used to make a map easy to use. We build a model of visual search for this design task and demonstrate how to apply it to the task…

The Visual System

Medline Plus

Full Text Available ... programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health ... Pressroom Contacts Dustin Hays - Chief, Science Communication dustin.hays@nih.gov Kathryn DeMott, Media Relations ...

The Visual System

Medline Plus

Full Text Available ... blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and requirements of the blind.” ... DeMott, Media Relations Kathryn.DeMott@nih.gov NEI Office of Communications ( ...

Digital Geologic Mapping and Integration with the Geoweb: The Death Knell for Exclusively Paper Geologic Maps

Science.gov (United States)

House, P. K.

2008-12-01

extremely useful accompaniment to compilation of field mapping efforts. It can also complement published geologic maps by vastly improving their comprehensibility when field photos, and specific notes can be viewed interactively with them. Other useful applications include GPS tracking/documentation of field traverses; invoking multiple geologic layers; 3-D visualizations of terrain and structure; and online collaboration with colleagues via blogs or wikis. Additional steps towards collaborative geologic mapping on the web may also enhance efficient and open sharing of data and ideas. Geologists are well aware that paper geologic maps can convey tremendous amounts of information. Digital geologic maps linked via a virtual globe with field data, diverse imagery, historical photographs, explanatory diagrams, and 3-D models convey a much greater amount of information and can provide a much richer context for comprehension and interpretation. They can also serve as an efficient, entertaining, and potentially compelling mechanism for fostering inspiration in the minds of budding (and aging) geologists.

Automatic Mapping of NES Games with Mappy

OpenAIRE

Osborn, Joseph C.; Summerville, Adam; Mateas, Michael

2017-01-01

Game maps are useful for human players, general-game-playing agents, and data-driven procedural content generation. These maps are generally made by hand-assembling manually-created screenshots of game levels. Besides being tedious and error-prone, this approach requires additional effort for each new game and level to be mapped. The results can still be hard for humans or computational systems to make use of, privileging visual appearance over semantic information. We describe a software sys...

Visualization of protein folding funnels in lattice models.

Directory of Open Access Journals (Sweden)

Antonio B Oliveira

Full Text Available Protein folding occurs in a very high dimensional phase space with an exponentially large number of states, and according to the energy landscape theory it exhibits a topology resembling a funnel. In this statistical approach, the folding mechanism is unveiled by describing the local minima in an effective one-dimensional representation. Other approaches based on potential energy landscapes address the hierarchical structure of local energy minima through disconnectivity graphs. In this paper, we introduce a metric to describe the distance between any two conformations, which also allows us to go beyond the one-dimensional representation and visualize the folding funnel in 2D and 3D. In this way it is possible to assess the folding process in detail, e.g., by identifying the connectivity between conformations and establishing the paths to reach the native state, in addition to regions where trapping may occur. Unlike the disconnectivity maps method, which is based on the kinetic connections between states, our methodology is based on structural similarities inferred from the new metric. The method was developed in a 27-mer protein lattice model, folded into a 3×3×3 cube. Five sequences were studied and distinct funnels were generated in an analysis restricted to conformations from the transition-state to the native configuration. Consistent with the expected results from the energy landscape theory, folding routes can be visualized to probe different regions of the phase space, as well as determine the difficulty in folding of the distinct sequences. Changes in the landscape due to mutations were visualized, with the comparison between wild and mutated local minima in a single map, which serves to identify different trapping regions. The extension of this approach to more realistic models and its use in combination with other approaches are discussed.

a Mapping Method of Slam Based on Look up Table

Science.gov (United States)

Wang, Z.; Li, J.; Wang, A.; Wang, J.

2017-09-01

In the last years several V-SLAM(Visual Simultaneous Localization and Mapping) approaches have appeared showing impressive reconstructions of the world. However these maps are built with far more than the required information. This limitation comes from the whole process of each key-frame. In this paper we present for the first time a mapping method based on the LOOK UP TABLE(LUT) for visual SLAM that can improve the mapping effectively. As this method relies on extracting features in each cell divided from image, it can get the pose of camera that is more representative of the whole key-frame. The tracking direction of key-frames is obtained by counting the number of parallax directions of feature points. LUT stored all mapping needs the number of cell corresponding to the tracking direction which can reduce the redundant information in the key-frame, and is more efficient to mapping. The result shows that a better map with less noise is build using less than one-third of the time. We believe that the capacity of LUT efficiently building maps makes it a good choice for the community to investigate in the scene reconstruction problems.

Mapping of mechanical properties of cast iron melts using non-destructive structuroscopy

Directory of Open Access Journals (Sweden)

J. Dočekal

2008-07-01

Full Text Available The contribution is focused on mapping of mechanical properties using methods of non-destructive structuroscopy of cast irons, which are a result of research at TU of Liberec and Institute of Physics of ASCR. Investigated samples become from melts of FOCAM s.r.o Olomouc Foundry shop. It compares data of mechanical properties obtained using ultrasound method with data from magnetic spot method and MAT. These are interpreted by mathematic models applicable in practice. In the following it concerns to derivation of loading tensile curve method, which can be used to obtain yield and fatigue strength limits even for cast irons with flake graphite. In spite of promising results reported by literature the experiments are bothered with error. This method can be applied to structure checking both before casting and at vendor inspection of castings.

Study of the mapping mechanism of ferroelectric domains with the scanning force microscope

International Nuclear Information System (INIS)

Jungk, T.

2006-12-01

The piezo-force microscopy (PFM) allows the mapping of ferroelectric domains until the nanometer range. In spite of its simple function principle it was hitherto not completely understood. In ordser to develop the PFM further to a quantitative analysis method its methodical aspects were analyzed. It was shown that the fundamental mapping mechanism is based on the inverse piezo-effect. Different artefacts to be found in the literature could therefore be reduced to a measurement background. Furthermore the influence of the electrode geometry was analyzed. The width of doamin walls was systematically measured and simulated with a mode, whereby a maximal resolution of 17 nm was reached. By the development of a correction procedure for the exact detection of the forces acting on the spring-beam the lateral signals measured on domain walls could by newly interpreted. So the ''Lateral Electrostatic Force Microscopy'' was developed

Visual Image Sensor Organ Replacement

Science.gov (United States)

Maluf, David A.

2014-01-01

This innovation is a system that augments human vision through a technique called "Sensing Super-position" using a Visual Instrument Sensory Organ Replacement (VISOR) device. The VISOR device translates visual and other sensors (i.e., thermal) into sounds to enable very difficult sensing tasks. Three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. Because the human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns, the translation of images into sounds reduces the risk of accidentally filtering out important clues. The VISOR device was developed to augment the current state-of-the-art head-mounted (helmet) display systems. It provides the ability to sense beyond the human visible light range, to increase human sensing resolution, to use wider angle visual perception, and to improve the ability to sense distances. It also allows compensation for movement by the human or changes in the scene being viewed.

The Visual System

Medline Plus

Full Text Available ... to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and requirements of ... Pressroom Contacts Dustin Hays - Chief, Science Communication dustin.hays@nih.gov Kathryn DeMott, Media Relations ...

Cortical Networks for Visual Self-Recognition

Science.gov (United States)

Sugiura, Motoaki

This paper briefly reviews recent developments regarding the brain mechanisms of visual self-recognition. A special cognitive mechanism for visual self-recognition has been postulated based on behavioral and neuropsychological evidence, but its neural substrate remains controversial. Recent functional imaging studies suggest that multiple cortical mechanisms play self-specific roles during visual self-recognition, reconciling the existing controversy. Respective roles for the left occipitotemporal, right parietal, and frontal cortices in symbolic, visuospatial, and conceptual aspects of self-representation have been proposed.

Cortical networks for visual self-recognition

International Nuclear Information System (INIS)