WorldWideScience

Sample records for visda modeling visualization

  1. caBIG™ VISDA: Modeling, visualization, and discovery for cluster analysis of genomic data

    Directory of Open Access Journals (Sweden)

    Xuan Jianhua

    2008-09-01

    Full Text Available Abstract Background The main limitations of most existing clustering methods used in genomic data analysis include heuristic or random algorithm initialization, the potential of finding poor local optima, the lack of cluster number detection, an inability to incorporate prior/expert knowledge, black-box and non-adaptive designs, in addition to the curse of dimensionality and the discernment of uninformative, uninteresting cluster structure associated with confounding variables. Results In an effort to partially address these limitations, we develop the VIsual Statistical Data Analyzer (VISDA for cluster modeling, visualization, and discovery in genomic data. VISDA performs progressive, coarse-to-fine (divisive hierarchical clustering and visualization, supported by hierarchical mixture modeling, supervised/unsupervised informative gene selection, supervised/unsupervised data visualization, and user/prior knowledge guidance, to discover hidden clusters within complex, high-dimensional genomic data. The hierarchical visualization and clustering scheme of VISDA uses multiple local visualization subspaces (one at each node of the hierarchy and consequent subspace data modeling to reveal both global and local cluster structures in a "divide and conquer" scenario. Multiple projection methods, each sensitive to a distinct type of clustering tendency, are used for data visualization, which increases the likelihood that cluster structures of interest are revealed. Initialization of the full dimensional model is based on first learning models with user/prior knowledge guidance on data projected into the low-dimensional visualization spaces. Model order selection for the high dimensional data is accomplished by Bayesian theoretic criteria and user justification applied via the hierarchy of low-dimensional visualization subspaces. Based on its complementary building blocks and flexible functionality, VISDA is generally applicable for gene clustering, sample

  2. caBIG VISDA: modeling, visualization, and discovery for cluster analysis of genomic data.

    Science.gov (United States)

    Zhu, Yitan; Li, Huai; Miller, David J; Wang, Zuyi; Xuan, Jianhua; Clarke, Robert; Hoffman, Eric P; Wang, Yue

    2008-09-18

    The main limitations of most existing clustering methods used in genomic data analysis include heuristic or random algorithm initialization, the potential of finding poor local optima, the lack of cluster number detection, an inability to incorporate prior/expert knowledge, black-box and non-adaptive designs, in addition to the curse of dimensionality and the discernment of uninformative, uninteresting cluster structure associated with confounding variables. In an effort to partially address these limitations, we develop the VIsual Statistical Data Analyzer (VISDA) for cluster modeling, visualization, and discovery in genomic data. VISDA performs progressive, coarse-to-fine (divisive) hierarchical clustering and visualization, supported by hierarchical mixture modeling, supervised/unsupervised informative gene selection, supervised/unsupervised data visualization, and user/prior knowledge guidance, to discover hidden clusters within complex, high-dimensional genomic data. The hierarchical visualization and clustering scheme of VISDA uses multiple local visualization subspaces (one at each node of the hierarchy) and consequent subspace data modeling to reveal both global and local cluster structures in a "divide and conquer" scenario. Multiple projection methods, each sensitive to a distinct type of clustering tendency, are used for data visualization, which increases the likelihood that cluster structures of interest are revealed. Initialization of the full dimensional model is based on first learning models with user/prior knowledge guidance on data projected into the low-dimensional visualization spaces. Model order selection for the high dimensional data is accomplished by Bayesian theoretic criteria and user justification applied via the hierarchy of low-dimensional visualization subspaces. Based on its complementary building blocks and flexible functionality, VISDA is generally applicable for gene clustering, sample clustering, and phenotype clustering

  3. caBIG™ VISDA: Modeling, visualization, and discovery for cluster analysis of genomic data

    Science.gov (United States)

    Zhu, Yitan; Li, Huai; Miller, David J; Wang, Zuyi; Xuan, Jianhua; Clarke, Robert; Hoffman, Eric P; Wang, Yue

    2008-01-01

    Background The main limitations of most existing clustering methods used in genomic data analysis include heuristic or random algorithm initialization, the potential of finding poor local optima, the lack of cluster number detection, an inability to incorporate prior/expert knowledge, black-box and non-adaptive designs, in addition to the curse of dimensionality and the discernment of uninformative, uninteresting cluster structure associated with confounding variables. Results In an effort to partially address these limitations, we develop the VIsual Statistical Data Analyzer (VISDA) for cluster modeling, visualization, and discovery in genomic data. VISDA performs progressive, coarse-to-fine (divisive) hierarchical clustering and visualization, supported by hierarchical mixture modeling, supervised/unsupervised informative gene selection, supervised/unsupervised data visualization, and user/prior knowledge guidance, to discover hidden clusters within complex, high-dimensional genomic data. The hierarchical visualization and clustering scheme of VISDA uses multiple local visualization subspaces (one at each node of the hierarchy) and consequent subspace data modeling to reveal both global and local cluster structures in a "divide and conquer" scenario. Multiple projection methods, each sensitive to a distinct type of clustering tendency, are used for data visualization, which increases the likelihood that cluster structures of interest are revealed. Initialization of the full dimensional model is based on first learning models with user/prior knowledge guidance on data projected into the low-dimensional visualization spaces. Model order selection for the high dimensional data is accomplished by Bayesian theoretic criteria and user justification applied via the hierarchy of low-dimensional visualization subspaces. Based on its complementary building blocks and flexible functionality, VISDA is generally applicable for gene clustering, sample clustering, and phenotype

  4. Visual Perceptual Learning and Models.

    Science.gov (United States)

    Dosher, Barbara; Lu, Zhong-Lin

    2017-09-15

    Visual perceptual learning through practice or training can significantly improve performance on visual tasks. Originally seen as a manifestation of plasticity in the primary visual cortex, perceptual learning is more readily understood as improvements in the function of brain networks that integrate processes, including sensory representations, decision, attention, and reward, and balance plasticity with system stability. This review considers the primary phenomena of perceptual learning, theories of perceptual learning, and perceptual learning's effect on signal and noise in visual processing and decision. Models, especially computational models, play a key role in behavioral and physiological investigations of the mechanisms of perceptual learning and for understanding, predicting, and optimizing human perceptual processes, learning, and performance. Performance improvements resulting from reweighting or readout of sensory inputs to decision provide a strong theoretical framework for interpreting perceptual learning and transfer that may prove useful in optimizing learning in real-world applications.

  5. Modeling human comprehension of data visualizations

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haass, Michael Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Divis, Kristin Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Andrew T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    This project was inspired by two needs. The first is a need for tools to help scientists and engineers to design effective data visualizations for communicating information, whether to the user of a system, an analyst who must make decisions based on complex data, or in the context of a technical report or publication. Most scientists and engineers are not trained in visualization design, and they could benefit from simple metrics to assess how well their visualization's design conveys the intended message. In other words, will the most important information draw the viewer's attention? The second is the need for cognition-based metrics for evaluating new types of visualizations created by researchers in the information visualization and visual analytics communities. Evaluating visualizations is difficult even for experts. However, all visualization methods and techniques are intended to exploit the properties of the human visual system to convey information efficiently to a viewer. Thus, developing evaluation methods that are rooted in the scientific knowledge of the human visual system could be a useful approach. In this project, we conducted fundamental research on how humans make sense of abstract data visualizations, and how this process is influenced by their goals and prior experience. We then used that research to develop a new model, the Data Visualization Saliency Model, that can make accurate predictions about which features in an abstract visualization will draw a viewer's attention. The model is an evaluation tool that can address both of the needs described above, supporting both visualization research and Sandia mission needs.

  6. Novel mathematical neural models for visual attention

    DEFF Research Database (Denmark)

    Li, Kang

    Visual attention has been extensively studied in psychology, but some fundamental questions remain controversial. We focus on two questions in this study. First, we investigate how a neuron in visual cortex responds to multiple stimuli inside the receptive eld, described by either a response...... for the visual attention theories and spiking neuron models for single spike trains. Statistical inference and model selection are performed and various numerical methods are explored. The designed methods also give a framework for neural coding under visual attention theories. We conduct both analysis on real...... system, supported by simulation study. Finally, we present the decoding of multiple temporal stimuli under these visual attention theories, also in a realistic biophysical situation with simulations....

  7. Automated visualization of rule-based models

    Science.gov (United States)

    Tapia, Jose-Juan; Faeder, James R.

    2017-01-01

    Frameworks such as BioNetGen, Kappa and Simmune use “reaction rules” to specify biochemical interactions compactly, where each rule specifies a mechanism such as binding or phosphorylation and its structural requirements. Current rule-based models of signaling pathways have tens to hundreds of rules, and these numbers are expected to increase as more molecule types and pathways are added. Visual representations are critical for conveying rule-based models, but current approaches to show rules and interactions between rules scale poorly with model size. Also, inferring design motifs that emerge from biochemical interactions is an open problem, so current approaches to visualize model architecture rely on manual interpretation of the model. Here, we present three new visualization tools that constitute an automated visualization framework for rule-based models: (i) a compact rule visualization that efficiently displays each rule, (ii) the atom-rule graph that conveys regulatory interactions in the model as a bipartite network, and (iii) a tunable compression pipeline that incorporates expert knowledge and produces compact diagrams of model architecture when applied to the atom-rule graph. The compressed graphs convey network motifs and architectural features useful for understanding both small and large rule-based models, as we show by application to specific examples. Our tools also produce more readable diagrams than current approaches, as we show by comparing visualizations of 27 published models using standard graph metrics. We provide an implementation in the open source and freely available BioNetGen framework, but the underlying methods are general and can be applied to rule-based models from the Kappa and Simmune frameworks also. We expect that these tools will promote communication and analysis of rule-based models and their eventual integration into comprehensive whole-cell models. PMID:29131816

  8. Automated visualization of rule-based models.

    Science.gov (United States)

    Sekar, John Arul Prakash; Tapia, Jose-Juan; Faeder, James R

    2017-11-01

    Frameworks such as BioNetGen, Kappa and Simmune use "reaction rules" to specify biochemical interactions compactly, where each rule specifies a mechanism such as binding or phosphorylation and its structural requirements. Current rule-based models of signaling pathways have tens to hundreds of rules, and these numbers are expected to increase as more molecule types and pathways are added. Visual representations are critical for conveying rule-based models, but current approaches to show rules and interactions between rules scale poorly with model size. Also, inferring design motifs that emerge from biochemical interactions is an open problem, so current approaches to visualize model architecture rely on manual interpretation of the model. Here, we present three new visualization tools that constitute an automated visualization framework for rule-based models: (i) a compact rule visualization that efficiently displays each rule, (ii) the atom-rule graph that conveys regulatory interactions in the model as a bipartite network, and (iii) a tunable compression pipeline that incorporates expert knowledge and produces compact diagrams of model architecture when applied to the atom-rule graph. The compressed graphs convey network motifs and architectural features useful for understanding both small and large rule-based models, as we show by application to specific examples. Our tools also produce more readable diagrams than current approaches, as we show by comparing visualizations of 27 published models using standard graph metrics. We provide an implementation in the open source and freely available BioNetGen framework, but the underlying methods are general and can be applied to rule-based models from the Kappa and Simmune frameworks also. We expect that these tools will promote communication and analysis of rule-based models and their eventual integration into comprehensive whole-cell models.

  9. Automated visualization of rule-based models.

    Directory of Open Access Journals (Sweden)

    John Arul Prakash Sekar

    2017-11-01

    Full Text Available Frameworks such as BioNetGen, Kappa and Simmune use "reaction rules" to specify biochemical interactions compactly, where each rule specifies a mechanism such as binding or phosphorylation and its structural requirements. Current rule-based models of signaling pathways have tens to hundreds of rules, and these numbers are expected to increase as more molecule types and pathways are added. Visual representations are critical for conveying rule-based models, but current approaches to show rules and interactions between rules scale poorly with model size. Also, inferring design motifs that emerge from biochemical interactions is an open problem, so current approaches to visualize model architecture rely on manual interpretation of the model. Here, we present three new visualization tools that constitute an automated visualization framework for rule-based models: (i a compact rule visualization that efficiently displays each rule, (ii the atom-rule graph that conveys regulatory interactions in the model as a bipartite network, and (iii a tunable compression pipeline that incorporates expert knowledge and produces compact diagrams of model architecture when applied to the atom-rule graph. The compressed graphs convey network motifs and architectural features useful for understanding both small and large rule-based models, as we show by application to specific examples. Our tools also produce more readable diagrams than current approaches, as we show by comparing visualizations of 27 published models using standard graph metrics. We provide an implementation in the open source and freely available BioNetGen framework, but the underlying methods are general and can be applied to rule-based models from the Kappa and Simmune frameworks also. We expect that these tools will promote communication and analysis of rule-based models and their eventual integration into comprehensive whole-cell models.

  10. Using Visualization Techniques in Multilayer Traffic Modeling

    Science.gov (United States)

    Bragg, Arnold

    We describe visualization techniques for multilayer traffic modeling - i.e., traffic models that span several protocol layers, and traffic models of protocols that cross layers. Multilayer traffic modeling is challenging, as one must deal with disparate traffic sources; control loops; the effects of network elements such as IP routers; cross-layer protocols; asymmetries in bandwidth, session lengths, and application behaviors; and an enormous number of complex interactions among the various factors. We illustrate by using visualization techniques to identify relationships, transformations, and scaling; to smooth simulation and measurement data; to examine boundary cases, subtle effects and interactions, and outliers; to fit models; and to compare models with others that have fewer parameters. Our experience suggests that visualization techniques can provide practitioners with extraordinary insight about complex multilayer traffic effects and interactions that are common in emerging next-generation networks.

  11. Visual and Computational Modelling of Minority Games

    Directory of Open Access Journals (Sweden)

    Robertas Damaševičius

    2017-02-01

    Full Text Available The paper analyses the Minority Game and focuses on analysis and computational modelling of several variants (variable payoff, coalition-based and ternary voting of Minority Game using UAREI (User-Action-Rule-Entities-Interface model. UAREI is a model for formal specification of software gamification, and the UAREI visual modelling language is a language used for graphical representation of game mechanics. The URAEI model also provides the embedded executable modelling framework to evaluate how the rules of the game will work for the players in practice. We demonstrate flexibility of UAREI model for modelling different variants of Minority Game rules for game design.

  12. Expressing Model Constraints Visually with VMQL

    DEFF Research Database (Denmark)

    Störrle, Harald

    2011-01-01

    OCL is the de facto standard language for expressing constraints and queries on UML models. However, OCL expressions are very difficult to create, understand, and maintain, even with the sophisticated tool support now available. In this paper, we propose to use the Visual Model Query Language (VMQL...

  13. Stereoscopic visual fatigue assessment and modeling

    Science.gov (United States)

    Wang, Danli; Wang, Tingting; Gong, Yue

    2014-03-01

    Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

  14. FLIP for FLAG model visualization

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, Hasani Omar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-15

    A graphical user interface has been developed for FLAG users. FLIP (FLAG Input deck Parser) provides users with an organized view of FLAG models and a means for efficiently and easily navigating and editing nodes, parameters, and variables.

  15. Integrating Visualizations into Modeling NEST Simulations

    Science.gov (United States)

    Nowke, Christian; Zielasko, Daniel; Weyers, Benjamin; Peyser, Alexander; Hentschel, Bernd; Kuhlen, Torsten W.

    2015-01-01

    Modeling large-scale spiking neural networks showing realistic biological behavior in their dynamics is a complex and tedious task. Since these networks consist of millions of interconnected neurons, their simulation produces an immense amount of data. In recent years it has become possible to simulate even larger networks. However, solutions to assist researchers in understanding the simulation's complex emergent behavior by means of visualization are still lacking. While developing tools to partially fill this gap, we encountered the challenge to integrate these tools easily into the neuroscientists' daily workflow. To understand what makes this so challenging, we looked into the workflows of our collaborators and analyzed how they use the visualizations to solve their daily problems. We identified two major issues: first, the analysis process can rapidly change focus which requires to switch the visualization tool that assists in the current problem domain. Second, because of the heterogeneous data that results from simulations, researchers want to relate data to investigate these effectively. Since a monolithic application model, processing and visualizing all data modalities and reflecting all combinations of possible workflows in a holistic way, is most likely impossible to develop and to maintain, a software architecture that offers specialized visualization tools that run simultaneously and can be linked together to reflect the current workflow, is a more feasible approach. To this end, we have developed a software architecture that allows neuroscientists to integrate visualization tools more closely into the modeling tasks. In addition, it forms the basis for semantic linking of different visualizations to reflect the current workflow. In this paper, we present this architecture and substantiate the usefulness of our approach by common use cases we encountered in our collaborative work. PMID:26733860

  16. Measuring Visual Closeness of 3-D Models

    KAUST Repository

    Gollaz Morales, Jose Alejandro

    2012-09-01

    Measuring visual closeness of 3-D models is an important issue for different problems and there is still no standardized metric or algorithm to do it. The normal of a surface plays a vital role in the shading of a 3-D object. Motivated by this, we developed two applications to measure visualcloseness, introducing normal difference as a parameter in a weighted metric in Metro’s sampling approach to obtain the maximum and mean distance between 3-D models using 3-D and 6-D correspondence search structures. A visual closeness metric should provide accurate information on what the human observers would perceive as visually close objects. We performed a validation study with a group of people to evaluate the correlation of our metrics with subjective perception. The results were positive since the metrics predicted the subjective rankings more accurately than the Hausdorff distance.

  17. 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,...

  18. Modeling Human Aesthetic Perception of Visual Textures

    NARCIS (Netherlands)

    Thumfart, Stefan; Jacobs, Richard H. A. H.; Lughofer, Edwin; Eitzinger, Christian; Cornelissen, Frans W.; Groissboeck, Werner; Richter, Roland

    2011-01-01

    Texture is extensively used in areas such as product design and architecture to convey specific aesthetic information. Using the results of a psychological experiment, we model the relationship between computational texture features and aesthetic properties of visual textures. Contrary to previous

  19. Modular target acquisition model & visualization tool

    NARCIS (Netherlands)

    Bijl, P.; Hogervorst, M.A.; Vos, W.K.

    2008-01-01

    We developed a software framework for image-based simulation models in the chain: scene-atmosphere-sensor-image enhancement-display-human observer: EO-VISTA. The goal is to visualize the steps and to quantify (Target Acquisition) task performance. EO-VISTA provides an excellent means to

  20. Numerical modeling of eastern connecticut's visual resources

    Science.gov (United States)

    Daniel L. Civco

    1979-01-01

    A numerical model capable of accurately predicting the preference for landscape photographs of selected points in eastern Connecticut is presented. A function of the social attitudes expressed toward thirty-two salient visual landscape features serves as the independent variable in predicting preferences. A technique for objectively assigning adjectives to landscape...

  1. An interference model of visual working memory.

    Science.gov (United States)

    Oberauer, Klaus; Lin, Hsuan-Yu

    2017-01-01

    The article introduces an interference model of working memory for information in a continuous similarity space, such as the features of visual objects. The model incorporates the following assumptions: (a) Probability of retrieval is determined by the relative activation of each retrieval candidate at the time of retrieval; (b) activation comes from 3 sources in memory: cue-based retrieval using context cues, context-independent memory for relevant contents, and noise; (c) 1 memory object and its context can be held in the focus of attention, where it is represented with higher precision, and partly shielded against interference. The model was fit to data from 4 continuous-reproduction experiments testing working memory for colors or orientations. The experiments involved variations of set size, kind of context cues, precueing, and retro-cueing of the to-be-tested item. The interference model fit the data better than 2 competing models, the Slot-Averaging model and the Variable-Precision resource model. The interference model also fared well in comparison to several new models incorporating alternative theoretical assumptions. The experiments confirm 3 novel predictions of the interference model: (a) Nontargets intrude in recall to the extent that they are close to the target in context space; (b) similarity between target and nontarget features improves recall, and (c) precueing-but not retro-cueing-the target substantially reduces the set-size effect. The success of the interference model shows that working memory for continuous visual information works according to the same principles as working memory for more discrete (e.g., verbal) contents. Data and model codes are available at https://osf.io/wgqd5/. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. Visual texture accurate material appearance measurement, representation and modeling

    CERN Document Server

    Haindl, Michal

    2013-01-01

    This book surveys the state of the art in multidimensional, physically-correct visual texture modeling. Features: reviews the entire process of texture synthesis, including material appearance representation, measurement, analysis, compression, modeling, editing, visualization, and perceptual evaluation; explains the derivation of the most common representations of visual texture, discussing their properties, advantages, and limitations; describes a range of techniques for the measurement of visual texture, including BRDF, SVBRDF, BTF and BSSRDF; investigates the visualization of textural info

  3. A model for visual memory encoding.

    Directory of Open Access Journals (Sweden)

    Rodolphe Nenert

    Full Text Available Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA. All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN. Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  4. A model for visual memory encoding.

    Science.gov (United States)

    Nenert, Rodolphe; Allendorfer, Jane B; Szaflarski, Jerzy P

    2014-01-01

    Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA) with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA). All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions) and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN). Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s) of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  5. Behavioral model of visual perception and recognition

    Science.gov (United States)

    Rybak, Ilya A.; Golovan, Alexander V.; Gusakova, Valentina I.

    1993-09-01

    In the processes of visual perception and recognition human eyes actively select essential information by way of successive fixations at the most informative points of the image. A behavioral program defining a scanpath of the image is formed at the stage of learning (object memorizing) and consists of sequential motor actions, which are shifts of attention from one to another point of fixation, and sensory signals expected to arrive in response to each shift of attention. In the modern view of the problem, invariant object recognition is provided by the following: (1) separated processing of `what' (object features) and `where' (spatial features) information at high levels of the visual system; (2) mechanisms of visual attention using `where' information; (3) representation of `what' information in an object-based frame of reference (OFR). However, most recent models of vision based on OFR have demonstrated the ability of invariant recognition of only simple objects like letters or binary objects without background, i.e. objects to which a frame of reference is easily attached. In contrast, we use not OFR, but a feature-based frame of reference (FFR), connected with the basic feature (edge) at the fixation point. This has provided for our model, the ability for invariant representation of complex objects in gray-level images, but demands realization of behavioral aspects of vision described above. The developed model contains a neural network subsystem of low-level vision which extracts a set of primary features (edges) in each fixation, and high- level subsystem consisting of `what' (Sensory Memory) and `where' (Motor Memory) modules. The resolution of primary features extraction decreases with distances from the point of fixation. FFR provides both the invariant representation of object features in Sensor Memory and shifts of attention in Motor Memory. Object recognition consists in successive recall (from Motor Memory) and execution of shifts of attention and

  6. Statistical modeling for visualization evaluation through data fusion.

    Science.gov (United States)

    Chen, Xiaoyu; Jin, Ran

    2017-11-01

    There is a high demand of data visualization providing insights to users in various applications. However, a consistent, online visualization evaluation method to quantify mental workload or user preference is lacking, which leads to an inefficient visualization and user interface design process. Recently, the advancement of interactive and sensing technologies makes the electroencephalogram (EEG) signals, eye movements as well as visualization logs available in user-centered evaluation. This paper proposes a data fusion model and the application procedure for quantitative and online visualization evaluation. 15 participants joined the study based on three different visualization designs. The results provide a regularized regression model which can accurately predict the user's evaluation of task complexity, and indicate the significance of all three types of sensing data sets for visualization evaluation. This model can be widely applied to data visualization evaluation, and other user-centered designs evaluation and data analysis in human factors and ergonomics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Modeling human judgments of urban visual air quality

    Science.gov (United States)

    Middleton, Paulette; Stewart, Thomas R.; Dennis, Robin L.

    The overall approach to establishing a complete predictive model link between pollutant emissions and human judgments of urban visual air quality (UVAQ) is presented. The field study design and data analysis procedures developed for analyzing the human components of visual air quality assessment are outlined. The air quality simulation model which relates pollutant emissions to human judgments of visual cues which comprise visual air quality judgments is described. Measured and modeled cues are compared for five typical visual air quality days in the winter of 1981 for Denver, Colorado. The comparisons suggest that the perceptual cue model, based on dispersion and radiative transfer theory, does not adequately predict human judgments of UVAQ cues. Analysis of the limits of predictability of the human judgments and the predictive capability of the model components indicates that the greatest improvements toward achieving a predictive UVAQ model lie in a reformulation of the theoretical descriptions of visual cues.

  8. A dual-trace model for visual sensory memory.

    Science.gov (United States)

    Cappiello, Marcus; Zhang, Weiwei

    2016-11-01

    Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. A visual approach for modeling spatiotemporal relations

    NARCIS (Netherlands)

    R.L. Guimarães (Rodrigo); C.S.S. Neto; L.F.G. Soares

    2008-01-01

    htmlabstractTextual programming languages have proven to be difficult to learn and to use effectively for many people. For this sake, visual tools can be useful to abstract the complexity of such textual languages, minimizing the specification efforts. In this paper we present a visual approach for

  10. Promoting Visualization Skills through Deconstruction Using Physical Models and a Visualization Activity Intervention

    Science.gov (United States)

    Schiltz, Holly Kristine

    Visualization skills are important in learning chemistry, as these skills have been shown to correlate to high ability in problem solving. Students' understanding of visual information and their problem-solving processes may only ever be accessed indirectly: verbalization, gestures, drawings, etc. In this research, deconstruction of complex visual concepts was aligned with the promotion of students' verbalization of visualized ideas to teach students to solve complex visual tasks independently. All instructional tools and teaching methods were developed in accordance with the principles of the theoretical framework, the Modeling Theory of Learning: deconstruction of visual representations into model components, comparisons to reality, and recognition of students' their problemsolving strategies. Three physical model systems were designed to provide students with visual and tangible representations of chemical concepts. The Permanent Reflection Plane Demonstration provided visual indicators that students used to support or invalidate the presence of a reflection plane. The 3-D Coordinate Axis system provided an environment that allowed students to visualize and physically enact symmetry operations in a relevant molecular context. The Proper Rotation Axis system was designed to provide a physical and visual frame of reference to showcase multiple symmetry elements that students must identify in a molecular model. Focus groups of students taking Inorganic chemistry working with the physical model systems demonstrated difficulty documenting and verbalizing processes and descriptions of visual concepts. Frequently asked student questions were classified, but students also interacted with visual information through gestures and model manipulations. In an effort to characterize how much students used visualization during lecture or recitation, we developed observation rubrics to gather information about students' visualization artifacts and examined the effect instructors

  11. A Hierarchical Visualization Analysis Model of Power Big Data

    Science.gov (United States)

    Li, Yongjie; Wang, Zheng; Hao, Yang

    2018-01-01

    Based on the conception of integrating VR scene and power big data analysis, a hierarchical visualization analysis model of power big data is proposed, in which levels are designed, targeting at different abstract modules like transaction, engine, computation, control and store. The regularly departed modules of power data storing, data mining and analysis, data visualization are integrated into one platform by this model. It provides a visual analysis solution for the power big data.

  12. Modeling and evaluating user behavior in exploratory visual analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reda, Khairi; Johnson, Andrew E.; Papka, Michael E.; Leigh, Jason

    2016-07-25

    Empirical evaluation methods for visualizations have traditionally focused on assessing the outcome of the visual analytic process as opposed to characterizing how that process unfolds. There are only a handful of methods that can be used to systematically study how people use visualizations, making it difficult for researchers to capture and characterize the subtlety of cognitive and interaction behaviors users exhibit during visual analysis. To validate and improve visualization design, however, it is important for researchers to be able to assess and understand how users interact with visualization systems under realistic scenarios. This paper presents a methodology for modeling and evaluating the behavior of users in exploratory visual analysis. We model visual exploration using a Markov chain process comprising transitions between mental, interaction, and computational states. These states and the transitions between them can be deduced from a variety of sources, including verbal transcripts, videos and audio recordings, and log files. This model enables the evaluator to characterize the cognitive and computational processes that are essential to insight acquisition in exploratory visual analysis, and reconstruct the dynamics of interaction between the user and the visualization system. We illustrate this model with two exemplar user studies, and demonstrate the qualitative and quantitative analytical tools it affords.

  13. DynaView: General Dynamic Visualization Model for SHM

    Directory of Open Access Journals (Sweden)

    Peng Sun

    2012-01-01

    Full Text Available We present a general dynamic visualization model named DynaView to construct virtual scenes of structural health monitoring (SHM process. This model consists of static, dynamic, and interaction submodels. It makes the visualization process dynamic and interactive. By taking an example of a simplified reinforced concrete beam structure model, we obtain raw data through the examination. We conduct the effective general and practicable assessment of structural damage conditions based on fuzzy pattern recognition to compute the assessment results. We construct the DynaView model of the sample structure and visualize it. The instance indicates that DynaView model is efficient and practically applicable.

  14. Visual fatigue modeling and analysis for stereoscopic video

    Science.gov (United States)

    Choi, Jaeseob; Kim, Donghyun; Choi, Sunghwan; Sohn, Kwanghoon

    2012-01-01

    In this paper, we propose a visual fatigue prediction method for stereoscopic video. We select visual fatigue factor candidates and determine the equations for each. The candidates are then classified into their principal components, and the validity of each is confirmed using principal component analysis. Visual fatigue is predicted using multiple regression with subjective visual fatigue. In order to determine the best model, we select the visual fatigue factors that have sufficient significance in terms of subjective fatigue according to the stepwise method. The predicted visual fatigue score is presented as a linear combination of the selected visual fatigue factors. Consequently, the proposed algorithm provides more reliable performance in terms of correlation with the subjective test results compared with a conventional algorithm.

  15. Modern Notation of Business Models: A Visual Trend

    OpenAIRE

    Tatiana Gavrilova; Artem Alsufyev; Anna-Sophia Yanson

    2014-01-01

    Information overflow and dynamic market changes encourage managers to search for a relevant and eloquent model to describe their business. This paper provides a new framework for visualizing business models, guided by well-shaped visualization based on a mind mapping technique introduced by Tony Buzan. The authors’ approach amplifies Alexander Ostervalder’s ideas on the new level of abstraction and well-structured description of business models. It also seeks to simplify the Osterwalder model...

  16. HMMEditor: a visual editing tool for profile hidden Markov model

    Directory of Open Access Journals (Sweden)

    Cheng Jianlin

    2008-03-01

    Full Text Available Abstract Background Profile Hidden Markov Model (HMM is a powerful statistical model to represent a family of DNA, RNA, and protein sequences. Profile HMM has been widely used in bioinformatics research such as sequence alignment, gene structure prediction, motif identification, protein structure prediction, and biological database search. However, few comprehensive, visual editing tools for profile HMM are publicly available. Results We develop a visual editor for profile Hidden Markov Models (HMMEditor. HMMEditor can visualize the profile HMM architecture, transition probabilities, and emission probabilities. Moreover, it provides functions to edit and save HMM and parameters. Furthermore, HMMEditor allows users to align a sequence against the profile HMM and to visualize the corresponding Viterbi path. Conclusion HMMEditor provides a set of unique functions to visualize and edit a profile HMM. It is a useful tool for biological sequence analysis and modeling. Both HMMEditor software and web service are freely available.

  17. Testing Neural Models of the Development of Infant Visual Attention

    OpenAIRE

    Richards, John E.; Hunter, Sharon K.

    2002-01-01

    Several models of the development of infant visual attention have used information about neural development. Most of these models have been based on nonhuman animal studies and have relied on indirect measures of neural development in human infants. This article discusses methods for studying a “neurodevelopmental” model of infant visual attention using indirect and direct measures of cortical activity. We concentrate on the effect of attention on eye movement control and show how animal-base...

  18. Computational Model of Primary Visual Cortex Combining Visual Attention for Action Recognition.

    Directory of Open Access Journals (Sweden)

    Na Shu

    Full Text Available Humans can easily understand other people's actions through visual systems, while computers cannot. Therefore, a new bio-inspired computational model is proposed in this paper aiming for automatic action recognition. The model focuses on dynamic properties of neurons and neural networks in the primary visual cortex (V1, and simulates the procedure of information processing in V1, which consists of visual perception, visual attention and representation of human action. In our model, a family of the three-dimensional spatial-temporal correlative Gabor filters is used to model the dynamic properties of the classical receptive field of V1 simple cell tuned to different speeds and orientations in time for detection of spatiotemporal information from video sequences. Based on the inhibitory effect of stimuli outside the classical receptive field caused by lateral connections of spiking neuron networks in V1, we propose surround suppressive operator to further process spatiotemporal information. Visual attention model based on perceptual grouping is integrated into our model to filter and group different regions. Moreover, in order to represent the human action, we consider the characteristic of the neural code: mean motion map based on analysis of spike trains generated by spiking neurons. The experimental evaluation on some publicly available action datasets and comparison with the state-of-the-art approaches demonstrate the superior performance of the proposed model.

  19. An efficient visual saliency detection model based on Ripplet transform

    Indian Academy of Sciences (India)

    A Diana Andrushia

    Abstract. Even though there have been great advancements in computer vision tasks, the development of human visual attention models is still not well investigated. In day-to-day life, one can find ample applications of saliency detection in image and video processing. This paper presents an efficient visual saliency ...

  20. Modeling the shape hierarchy for visually guided grasping

    CSIR Research Space (South Africa)

    Rezai, O

    2014-10-01

    Full Text Available The monkey anterior intraparietal area (AIP) encodes visual information about three-dimensional object shape that is used to shape the hand for grasping. We modeled shape tuning in visual AIP neurons and its relationship with curvature and gradient...

  1. Mental models, visual reasoning and interaction in information visualization: a top-down perspective.

    Science.gov (United States)

    Liu, Zhicheng; Stasko, John T

    2010-01-01

    Although previous research has suggested that examining the interplay between internal and external representations can benefit our understanding of the role of information visualization (InfoVis) in human cognitive activities, there has been little work detailing the nature of internal representations, the relationship between internal and external representations and how interaction is related to these representations. In this paper, we identify and illustrate a specific kind of internal representation, mental models, and outline the high-level relationships between mental models and external visualizations. We present a top-down perspective of reasoning as model construction and simulation, and discuss the role of visualization in model based reasoning. From this perspective, interaction can be understood as active modeling for three primary purposes: external anchoring, information foraging, and cognitive offloading. Finally we discuss the implications of our approach for design, evaluation and theory development.

  2. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

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

    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...... show that the performance of linear models is reduced for certain scan labelings/categorizations in this data set, while the nonlinear models provide more flexibility. We show that the sensitivity map can be used to visualize nonlinear versions of kernel logistic regression, the kernel Fisher...

  3. A novel visualization model for web search results.

    Science.gov (United States)

    Nguyen, Tien N; Zhang, Jin

    2006-01-01

    This paper presents an interactive visualization system, named WebSearchViz, for visualizing the Web search results and acilitating users' navigation and exploration. The metaphor in our model is the solar system with its planets and asteroids revolving around the sun. Location, color, movement, and spatial distance of objects in the visual space are used to represent the semantic relationships between a query and relevant Web pages. Especially, the movement of objects and their speeds add a new dimension to the visual space, illustrating the degree of relevance among a query and Web search results in the context of users' subjects of interest. By interacting with the visual space, users are able to observe the semantic relevance between a query and a resulting Web page with respect to their subjects of interest, context information, or concern. Users' subjects of interest can be dynamically changed, redefined, added, or deleted from the visual space.

  4. Terminology model discovery using natural language processing and visualization techniques.

    Science.gov (United States)

    Zhou, Li; Tao, Ying; Cimino, James J; Chen, Elizabeth S; Liu, Hongfang; Lussier, Yves A; Hripcsak, George; Friedman, Carol

    2006-12-01

    Medical terminologies are important for unambiguous encoding and exchange of clinical information. The traditional manual method of developing terminology models is time-consuming and limited in the number of phrases that a human developer can examine. In this paper, we present an automated method for developing medical terminology models based on natural language processing (NLP) and information visualization techniques. Surgical pathology reports were selected as the testing corpus for developing a pathology procedure terminology model. The use of a general NLP processor for the medical domain, MedLEE, provides an automated method for acquiring semantic structures from a free text corpus and sheds light on a new high-throughput method of medical terminology model development. The use of an information visualization technique supports the summarization and visualization of the large quantity of semantic structures generated from medical documents. We believe that a general method based on NLP and information visualization will facilitate the modeling of medical terminologies.

  5. Data-driven approach to dynamic visual attention modelling

    Science.gov (United States)

    Culibrk, Dubravko; Sladojevic, Srdjan; Riche, Nicolas; Mancas, Matei; Crnojevic, Vladimir

    2012-06-01

    Visual attention deployment mechanisms allow the Human Visual System to cope with an overwhelming amount of visual data by dedicating most of the processing power to objects of interest. The ability to automatically detect areas of the visual scene that will be attended to by humans is of interest for a large number of applications, from video coding, video quality assessment to scene understanding. Due to this fact, visual saliency (bottom-up attention) models have generated significant scientific interest in recent years. Most recent work in this area deals with dynamic models of attention that deal with moving stimuli (videos) instead of traditionally used still images. Visual saliency models are usually evaluated against ground-truth eye-tracking data collected from human subjects. However, there are precious few recently published approaches that try to learn saliency from eyetracking data and, to the best of our knowledge, no approaches that try to do so when dynamic saliency is concerned. The paper attempts to fill this gap and describes an approach to data-driven dynamic saliency model learning. A framework is proposed that enables the use of eye-tracking data to train an arbitrary machine learning algorithm, using arbitrary features derived from the scene. We evaluate the methodology using features from a state-of-the art dynamic saliency model and show how simple machine learning algorithms can be trained to distinguish between visually salient and non-salient parts of the scene.

  6. Visual modeling in an analysis of multidimensional data

    Science.gov (United States)

    Zakharova, A. A.; Vekhter, E. V.; Shklyar, A. V.; Pak, A. J.

    2018-01-01

    The article proposes an approach to solve visualization problems and the subsequent analysis of multidimensional data. Requirements to the properties of visual models, which were created to solve analysis problems, are described. As a perspective direction for the development of visual analysis tools for multidimensional and voluminous data, there was suggested an active use of factors of subjective perception and dynamic visualization. Practical results of solving the problem of multidimensional data analysis are shown using the example of a visual model of empirical data on the current state of studying processes of obtaining silicon carbide by an electric arc method. There are several results of solving this problem. At first, an idea of possibilities of determining the strategy for the development of the domain, secondly, the reliability of the published data on this subject, and changes in the areas of attention of researchers over time.

  7. How do People Make Sense of Unfamiliar Visualizations?: A Grounded Model of Novice's Information Visualization Sensemaking.

    Science.gov (United States)

    Lee, Sukwon; Kim, Sung-Hee; Hung, Ya-Hsin; Lam, Heidi; Kang, Youn-ah; Yi, Ji Soo

    2016-01-01

    In this paper, we would like to investigate how people make sense of unfamiliar information visualizations. In order to achieve the research goal, we conducted a qualitative study by observing 13 participants when they endeavored to make sense of three unfamiliar visualizations (i.e., a parallel-coordinates plot, a chord diagram, and a treemap) that they encountered for the first time. We collected data including audio/video record of think-aloud sessions and semi-structured interview; and analyzed the data using the grounded theory method. The primary result of this study is a grounded model of NOvice's information Vlsualization Sensemaking (NOVIS model), which consists of the five major cognitive activities: 1 encountering visualization, 2 constructing a frame, 3 exploring visualization, 4 questioning the frame, and 5 floundering on visualization. We introduce the NOVIS model by explaining the five activities with representative quotes from our participants. We also explore the dynamics in the model. Lastly, we compare with other existing models and share further research directions that arose from our observations.

  8. Model of visual search and selection time in linear menus

    OpenAIRE

    Bailly, G.; Oulasvirta, A.; Brumby, D. P.; Howes, A.

    2014-01-01

    This paper presents a novel mathematical model for visual search and selection time in linear menus. Assuming two visual search strategies, serial and directed, and a pointing sub-task, it captures the change of performance with five factors: 1) menu length, 2) menu organization, 3) target position, 4) absence/presence of target, and 5) practice. The novel aspect is that the model is expressed as probability density distribution of gaze, which allows for deriving total selection time. We pres...

  9. VCMM: a visual tool for continuum molecular modeling.

    Science.gov (United States)

    Bai, Shiyang; Lu, Benzhuo

    2014-05-01

    This paper describes the design and function of a visualization tool, VCMM, for visualizing and analyzing data, and interfacing solvers for generic continuum molecular modeling. In particular, an emphasis of the program is to treat the data set based on unstructured mesh as used in finite/boundary element simulations, which largely enhances the capabilities of current visualization tools in this area that only support structured mesh. VCMM is segmented into molecular, meshing and numerical modules. The capabilities of molecular module include molecular visualization and force field assignment. Meshing module contains mesh generation, analysis and visualization tools. Numerical module currently provides a few finite/boundary element solvers of continuum molecular modeling, and contains several common visualization tools for the numerical result such as line and plane interpolations, surface probing, volume rendering and stream rendering. Three modules can exchange data with each other and carry out a complete process of modeling. Interfaces are also designed in order to facilitate usage of other mesh generation tools and numerical solvers. We develop a technique to accelerate data retrieval and have combined many graphical techniques in visualization. VCMM is highly extensible, and users can obtain more powerful functions by introducing relevant plug-ins. VCMM can also be useful in other fields such as computational quantum chemistry, image processing, and material science. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Elementary Teachers' Selection and Use of Visual Models

    Science.gov (United States)

    Lee, Tammy D.; Jones, M. Gail

    2018-01-01

    As science grows in complexity, science teachers face an increasing challenge of helping students interpret models that represent complex science systems. Little is known about how teachers select and use models when planning lessons. This mixed methods study investigated the pedagogical approaches and visual models used by elementary in-service…

  11. A Dynamic Systems Theory Model of Visual Perception Development

    Science.gov (United States)

    Coté, Carol A.

    2015-01-01

    This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…

  12. Visual Middle-Out Modeling of Problem Spaces

    DEFF Research Database (Denmark)

    Valente, Andrea

    2009-01-01

    Modeling is a complex and central activity in many domains. Domain experts and designers usually work by drawing and create models from the middle-out; however, visual and middle-out style modeling is poorly supported by software tools. In order to define a new class of software-based modeling...... tools, we propose a scenario and identify some requirements. Those requirements are contrasted against features of existing tools from various application domains, and the results show general lack of support for custom visualization and incremental knowledge specification, poor handling of temporal...

  13. Spatial Uncertainty Model for Visual Features Using a Kinect™ Sensor

    Directory of Open Access Journals (Sweden)

    Jae-Han Park

    2012-06-01

    Full Text Available This study proposes a mathematical uncertainty model for the spatial measurement of visual features using Kinect™ sensors. This model can provide qualitative and quantitative analysis for the utilization of Kinect™ sensors as 3D perception sensors. In order to achieve this objective, we derived the propagation relationship of the uncertainties between the disparity image space and the real Cartesian space with the mapping function between the two spaces. Using this propagation relationship, we obtained the mathematical model for the covariance matrix of the measurement error, which represents the uncertainty for spatial position of visual features from Kinect™ sensors. In order to derive the quantitative model of spatial uncertainty for visual features, we estimated the covariance matrix in the disparity image space using collected visual feature data. Further, we computed the spatial uncertainty information by applying the covariance matrix in the disparity image space and the calibrated sensor parameters to the proposed mathematical model. This spatial uncertainty model was verified by comparing the uncertainty ellipsoids for spatial covariance matrices and the distribution of scattered matching visual features. We expect that this spatial uncertainty model and its analyses will be useful in various Kinect™ sensor applications.

  14. A feedback model of visual attention

    OpenAIRE

    Spratling, M. W.; Johnson, M H

    2004-01-01

    Feedback connections are a prominent feature of cortical anatomy and are likely to have a significant functional role in neural information processing. We present a neural network model of cortical feedback that successfully simulates neurophysiological data associated with attention. In this domain, our model can be considered a more detailed, and biologically plausible, implementation of the biased competition model of attention. However, our model is more general as it can also explain a v...

  15. Modeling and visualizing borehole information on virtual globes using KML

    Science.gov (United States)

    Zhu, Liang-feng; Wang, Xi-feng; Zhang, Bing

    2014-01-01

    Advances in virtual globes and Keyhole Markup Language (KML) are providing the Earth scientists with the universal platforms to manage, visualize, integrate and disseminate geospatial information. In order to use KML to represent and disseminate subsurface geological information on virtual globes, we present an automatic method for modeling and visualizing a large volume of borehole information. Based on a standard form of borehole database, the method first creates a variety of borehole models with different levels of detail (LODs), including point placemarks representing drilling locations, scatter dots representing contacts and tube models representing strata. Subsequently, the level-of-detail based (LOD-based) multi-scale representation is constructed to enhance the efficiency of visualizing large numbers of boreholes. Finally, the modeling result can be loaded into a virtual globe application for 3D visualization. An implementation program, termed Borehole2KML, is developed to automatically convert borehole data into KML documents. A case study of using Borehole2KML to create borehole models in Shanghai shows that the modeling method is applicable to visualize, integrate and disseminate borehole information on the Internet. The method we have developed has potential use in societal service of geological information.

  16. The Theory of Visual Attention without the race: a new model of visual selection

    DEFF Research Database (Denmark)

    Andersen, Tobias; Kyllingsbæk, Søren

    2012-01-01

    constrained by a limited processing capacity or rate, which is distributed among target and distractor objects with distractor objects receiving a smaller proportion of resources due to attentional filtering. Encoding into a limited visual short-term memory is implemented as a race model. Given its major...

  17. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular within the neuroimaging community. Such methods attempt...... to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical neuroimaging data...... sets are characterized by relatively few data observations in a high dimensional space. The process of building models in such data sets often requires strong regularization. Often, the degree of model regularization is chosen in order to maximize prediction accuracy. We focus on the relative influence...

  18. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    2012-01-01

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular analysis tools within the neuroimaging community. Such methods...... attempt to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical...... neuroimaging data sets are characterized by relatively few data observations in a high dimensional space. The process of building models in such data sets often requires strong regularization. Often, the degree of model regularization is chosen in order to maximize prediction accuracy. We focus on the relative...

  19. A model of visual, aesthetic communication focusing on web sites

    DEFF Research Database (Denmark)

    Thorlacius, Lisbeth

    2002-01-01

    design. With a point of departure in Roman Jakobson's linguistic communication model, the reader is introduced to a model which covers the communication aspects, the visual aspects, the aesthetic aspects and the net specific aspects of the analysis of media products. The aesthetic aspects rank low......Theory books and method books within the field of web design mainly focus on the technical and functional aspects of the construction of web design. There is a lack of a model which weighs the analysis of the visual and aesthetic aspects against the the functional and technical aspects of web...

  20. Variational adaptive image denoising model based on human visual system

    Science.gov (United States)

    Li, Wenjun; Liu, Chanjuan; Zou, Hailin

    2011-11-01

    A variational image adaptive denoising model based on human visual system is proposed by introducing control parameter p which can determine the diffusion intensity to Total Variation (TV) model. The model can adaptively select the value of parameter p according to human visual system noise visibility value of each pixel which makes diffusion intensity close to edges smaller than those far away from edges. For this method is more consistent with human perception, human eyes can perceive the improvement of image quality intuitively. Numerical experiments show that the proposed method can overcome staircase effect, remove the noise while preserving significant image details and better performance has been achieved.

  1. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Lund, Torben Ellegaard

    2011-01-01

    that the performance of linear models is reduced for certain scan labelings/categorizations in this data set, while the nonlinear models provide more flexibility. We show that the sensitivity map can be used to visualize nonlinear versions of kernel logistic regression, the kernel Fisher discriminant, and the SVM...

  2. Task-specific visual cues for improving process model understanding

    NARCIS (Netherlands)

    Petrusel, Razvan; Mendling, Jan; Reijers, Hajo A.

    2016-01-01

    Context Business process models support various stakeholders in managing business processes and designing process-aware information systems. In order to make effective use of these models, they have to be readily understandable. Objective Prior research has emphasized the potential of visual cues to

  3. Visualizations and Mental Models - The Educational Implications of GEOWALL

    Science.gov (United States)

    Rapp, D.; Kendeou, P.

    2003-12-01

    Work in the earth sciences has outlined many of the faulty beliefs that students possess concerning particular geological systems and processes. Evidence from educational and cognitive psychology has demonstrated that students often have difficulty overcoming their na‹ve beliefs about science. Prior knowledge is often remarkably resistant to change, particularly when students' existing mental models for geological principles may be faulty or inaccurate. Figuring out how to help students revise their mental models to include appropriate information is a major challenge. Up until this point, research has tended to focus on whether 2-dimensional computer visualizations are useful tools for helping students develop scientifically correct models. Research suggests that when students are given the opportunity to use dynamic computer-based visualizations, they are more likely to recall the learned information, and are more likely to transfer that knowledge to novel settings. Unfortunately, 2-dimensional visualization systems are often inadequate representations of the material that educators would like students to learn. For example, a 2-dimensional image of the Earth's surface does not adequately convey particular features that are critical for visualizing the geological environment. This may limit the models that students can construct following these visualizations. GEOWALL is a stereo projection system that has attempted to address this issue. It can display multidimensional static geologic images and dynamic geologic animations in a 3-dimensional format. Our current research examines whether multidimensional visualization systems such as GEOWALL may facilitate learning by helping students to develop more complex mental models. This talk will address some of the cognitive issues that influence the construction of mental models, and the difficulty of updating existing mental models. We will also discuss our current work that seeks to examine whether GEOWALL is an

  4. MODELLING SYNERGISTIC EYE MOVEMENTS IN THE VISUAL FIELD

    Directory of Open Access Journals (Sweden)

    BARITZ Mihaela

    2015-06-01

    Full Text Available Some theoretical and practical considerations about eye movements in visual field are presented in the first part of this paper. These movements are developed into human body to be synergistic and are allowed to obtain the visual perception in 3D space. The theoretical background of the eye movements’ analysis is founded on the establishment of movement equations of the eyeball, as they consider it a solid body with a fixed point. The exterior actions, the order and execution of the movements are ensured by the neural and muscular external system and thus the position, stability and movements of the eye can be quantified through the method of reverse kinematic. The purpose of these researches is the development of a simulation model of human binocular visual system, an acquisition methodology and an experimental setup for data processing and recording regarding the eye movements, presented in the second part of the paper. The modeling system of ocular movements aims to establish the binocular synergy and limits of visual field changes in condition of ocular motor dysfunctions. By biomechanical movements of eyeball is established a modeling strategy for different sort of processes parameters like convergence, fixation and eye lens accommodation to obtain responses from binocular balance. The results of modelling processes and the positions of eye ball and axis in visual field are presented in the final part of the paper.

  5. Self-paced model learning for robust visual tracking

    Science.gov (United States)

    Huang, Wenhui; Gu, Jason; Ma, Xin; Li, Yibin

    2017-01-01

    In visual tracking, learning a robust and efficient appearance model is a challenging task. Model learning determines both the strategy and the frequency of model updating, which contains many details that could affect the tracking results. Self-paced learning (SPL) has recently been attracting considerable interest in the fields of machine learning and computer vision. SPL is inspired by the learning principle underlying the cognitive process of humans, whose learning process is generally from easier samples to more complex aspects of a task. We propose a tracking method that integrates the learning paradigm of SPL into visual tracking, so reliable samples can be automatically selected for model learning. In contrast to many existing model learning strategies in visual tracking, we discover the missing link between sample selection and model learning, which are combined into a single objective function in our approach. Sample weights and model parameters can be learned by minimizing this single objective function. Additionally, to solve the real-valued learning weight of samples, an error-tolerant self-paced function that considers the characteristics of visual tracking is proposed. We demonstrate the robustness and efficiency of our tracker on a recent tracking benchmark data set with 50 video sequences.

  6. Method and apparatus for modeling, visualization and analysis of materials

    KAUST Repository

    Aboulhassan, Amal

    2016-08-25

    A method, apparatus, and computer readable medium are provided for modeling of materials and visualization of properties of the materials. An example method includes receiving data describing a set of properties of a material, and computing, by a processor and based on the received data, geometric features of the material. The example method further includes extracting, by the processor, particle paths within the material based on the computed geometric features, and geometrically modeling, by the processor, the material using the geometric features and the extracted particle paths. The example method further includes generating, by the processor and based on the geometric modeling of the material, one or more visualizations regarding the material, and causing display, by a user interface, of the one or more visualizations.

  7. Visual prosthesis wireless energy transfer system optimal modeling.

    Science.gov (United States)

    Li, Xueping; Yang, Yuan; Gao, Yong

    2014-01-16

    Wireless energy transfer system is an effective way to solve the visual prosthesis energy supply problems, theoretical modeling of the system is the prerequisite to do optimal energy transfer system design. On the basis of the ideal model of the wireless energy transfer system, according to visual prosthesis application condition, the system modeling is optimized. During the optimal modeling, taking planar spiral coils as the coupling devices between energy transmitter and receiver, the effect of the parasitic capacitance of the transfer coil is considered, and especially the concept of biological capacitance is proposed to consider the influence of biological tissue on the energy transfer efficiency, resulting in the optimal modeling's more accuracy for the actual application. The simulation data of the optimal model in this paper is compared with that of the previous ideal model, the results show that under high frequency condition, the parasitic capacitance of inductance and biological capacitance considered in the optimal model could have great impact on the wireless energy transfer system. The further comparison with the experimental data verifies the validity and accuracy of the optimal model proposed in this paper. The optimal model proposed in this paper has a higher theoretical guiding significance for the wireless energy transfer system's further research, and provide a more precise model reference for solving the power supply problem in visual prosthesis clinical application.

  8. Temporal perceptual coding using a visual acuity model

    Science.gov (United States)

    Adzic, Velibor; Cohen, Robert A.; Vetro, Anthony

    2014-02-01

    This paper describes research and results in which a visual acuity (VA) model of the human visual system (HVS) is used to reduce the bitrate of coded video sequences, by eliminating the need to signal transform coefficients when their corresponding frequencies will not be detected by the HVS. The VA model is integrated into the state of the art HEVC HM codec. Compared to the unmodified codec, up to 45% bitrate savings are achieved while maintaining the same subjective quality of the video sequences. Encoding times are reduced as well.

  9. An Architectural Model of Visual Motion Understanding

    Science.gov (United States)

    1989-08-01

    research environments on earth; particularly Peggy Frantz, Jill Orioli Forster, and Peg Meeker, whose competence is matched only by their patience with...idea of competition for ownership of evidence, which is the essence of the feature binding, has occurred in a few other contexts. Levitt [ Levitt , 19861...Physiology, 250:347-366, 1985. [ Levitt , 1986] Tod S. Levitt , "Model-based Probabilistic Situation Inference in Hier- archical Hypothesis Spaces," In L

  10. A probabilistic model for visual inspection of concrete shear walls

    Science.gov (United States)

    Ebrahimkhanlou, Arvin; Salamone, Salvatore

    2017-04-01

    This paper presents a probabilistic model, called Bayesian networks, to visually assess the state of damage in reinforced concrete shear walls. The goal of this research is to reduce the inspection time and decrease the chance of missing or underestimating the state of damage in such structures. To develop this model, we define six types of visible damage on concrete shear walls. The model describes the causal relationship of such damage signs with the design parameters and damage states of the walls. To train and test the model, a database of all visually documented experimental works on concrete shear walls was collected from the literature. The model is trained on ninety percent of the database, and its performance is successfully validated on the ten percent remaining unseen portion of the database. The results show that the model can classify the images of yielded and failed walls. Additionally, it can prognosticate the most probable failure scenario for a yielded wall.

  11. Experimental validation of a Bayesian model of visual acuity.

    LENUS (Irish Health Repository)

    Dalimier, Eugénie

    2009-01-01

    Based on standard procedures used in optometry clinics, we compare measurements of visual acuity for 10 subjects (11 eyes tested) in the presence of natural ocular aberrations and different degrees of induced defocus, with the predictions given by a Bayesian model customized with aberrometric data of the eye. The absolute predictions of the model, without any adjustment, show good agreement with the experimental data, in terms of correlation and absolute error. The efficiency of the model is discussed in comparison with image quality metrics and other customized visual process models. An analysis of the importance and customization of each stage of the model is also given; it stresses the potential high predictive power from precise modeling of ocular and neural transfer functions.

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

    Science.gov (United States)

    Hager, Christine

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

  13. Psychological Correlates of a Model of the Human Visual System

    Science.gov (United States)

    A model of the human visual system is investigated for psychological correlates. A priori hypotheses from the model concerned with human...identification of defocused letters as well as identification of rotated letters have been validated with the computer model. Gestalt principles of similarity...is also psychologically correlated. It is further postulated that the human perceptual space is the image domain from spatially filtered transforms of

  14. Modeling the Visual and Linguistic Importance of Objects

    Directory of Open Access Journals (Sweden)

    Moreno Ignazio Coco

    2012-05-01

    Full Text Available Previous work measuring the visual importance of objects has shown that only spatial information, such as object position and size, is predictive of importance, whilst low-level visual information, such as saliency, is not (Spain and Perona 2010, IJCV 91, 59–76. Objects are not important solely on the basis of their appearance. Rather, they are important because of their contextual information (eg, a pen in an office versus in a bathroom, which is needed in tasks requiring cognitive control (eg, visual search; Henderson 2007, PsySci 16 219–222. Given that most visual objects have a linguistic counterpart, their importance depends also on linguistic information, especially in tasks where language is actively involved—eg, naming. In an eye-tracking naming study, where participants are asked to name 5 objects in a scene, we investigated how visual saliency, contextual features, and linguistic information of the mentioned objects predicted their importance. We measured object importance based on the urn model of Spain and Perona (2010 and estimated the predictive role of visual and linguistic features using different regression frameworks: LARS (Efron et al 2004, Annals of Statistics 32 407–499 and LME (Baayen et al 2008, JML 59, 390–412. Our results confirmed the role of spatial information in predicting object importance, and in addition, we found effects of saliency. Crucially to our hypothesis, we demonstrated that the lexical frequency of objects and their contextual fit in the scene significantly contributed to object importance.

  15. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, P.M.; Madsen, Kristoffer H; Lund, T.E.

    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...... discriminant, and the SVM, and conclude that the sensitivity map is a versatile and computationally efficient tool for visualization of nonlinear kernel models in neuroimaging...

  16. Robust Visual Tracking via Exclusive Context Modeling

    KAUST Repository

    Zhang, Tianzhu

    2015-02-09

    In this paper, we formulate particle filter-based object tracking as an exclusive sparse learning problem that exploits contextual information. To achieve this goal, we propose the context-aware exclusive sparse tracker (CEST) to model particle appearances as linear combinations of dictionary templates that are updated dynamically. Learning the representation of each particle is formulated as an exclusive sparse representation problem, where the overall dictionary is composed of multiple {group} dictionaries that can contain contextual information. With context, CEST is less prone to tracker drift. Interestingly, we show that the popular L₁ tracker [1] is a special case of our CEST formulation. The proposed learning problem is efficiently solved using an accelerated proximal gradient method that yields a sequence of closed form updates. To make the tracker much faster, we reduce the number of learning problems to be solved by using the dual problem to quickly and systematically rank and prune particles in each frame. We test our CEST tracker on challenging benchmark sequences that involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that CEST consistently outperforms state-of-the-art trackers.

  17. Modeling Visual Symptoms and Visual Skills to Measure Functional Binocular Vision

    Science.gov (United States)

    Powers, M. K.; Fisher, W. P., Jr.; Massof, R. W.

    2016-11-01

    Obtaining a clear image of the world depends on good eye coordination (“binocular vision”). Yet no standard exists by which to determine a threshold for good vs poor binocular vision, as exists for the eye chart and visual acuity. We asked whether data on the signs and symptoms related to binocular vision are sufficiently consistent with children's self-reported visual symptoms to substantiate a construct model of Functional Binocular Vision (FBV), and then whether that model can be used to aggregate clinical and survey observations into a meaningful diagnostic measure. Data on visual symptoms from 1,100 children attending school in Los Angeles were obtained using the Convergence Insufficiency Symptom Survey (CISS); and for more than 300 students in that sample, 35 additional measures were taken, including acuity, cover test near and far, near point of convergence, near point of accommodation, accommodative facility, vergence ranges, tracking ability, and oral reading fluency. A preliminary analysis of data from the 15-item, 5-category CISS and 15 clinical variables from 103 grade school students who reported convergence problems (CISS scores of 16 or higher) suggests that the clinical and survey observations will be optimally combined in a multidimensional model.

  18. Visualization of 3D Geological Models on Google Earth

    Science.gov (United States)

    Choi, Y.; Um, J.; Park, M.

    2013-05-01

    Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth

  19. Ophiucus: RDF-based visualization tool for health simulation models.

    Science.gov (United States)

    Sutcliffe, Andrew; Okhmatovskaia, Anya; Shaban-Nejad, Arash; Buckeridge, David

    2012-01-01

    Simulation modeling of population health is becoming increasingly popular for epidemiology research and public health policy-making. However, the acceptability of population health simulation models is inhibited by their complexity and the lack of established standards to describe these models. To address this issue, we propose Ophiuchus - an RDF (Resource Description Framework: http://www.w3.org/RDF/)-based visualization tool for generating interactive 2D diagrams of population health simulation models, which describe these models in an explicit and formal manner. We present the results of a preliminary system assessment and discuss current limitations of the system.

  20. Elementary Teachers' Selection and Use of Visual Models

    Science.gov (United States)

    Lee, Tammy D.; Gail Jones, M.

    2018-02-01

    As science grows in complexity, science teachers face an increasing challenge of helping students interpret models that represent complex science systems. Little is known about how teachers select and use models when planning lessons. This mixed methods study investigated the pedagogical approaches and visual models used by elementary in-service and preservice teachers in the development of a science lesson about a complex system (e.g., water cycle). Sixty-seven elementary in-service and 69 elementary preservice teachers completed a card sort task designed to document the types of visual models (e.g., images) that teachers choose when planning science instruction. Quantitative and qualitative analyses were conducted to analyze the card sort task. Semistructured interviews were conducted with a subsample of teachers to elicit the rationale for image selection. Results from this study showed that both experienced in-service teachers and novice preservice teachers tended to select similar models and use similar rationales for images to be used in lessons. Teachers tended to select models that were aesthetically pleasing and simple in design and illustrated specific elements of the water cycle. The results also showed that teachers were not likely to select images that represented the less obvious dimensions of the water cycle. Furthermore, teachers selected visual models more as a pedagogical tool to illustrate specific elements of the water cycle and less often as a tool to promote student learning related to complex systems.

  1. Elementary Teachers' Selection and Use of Visual Models

    Science.gov (United States)

    Lee, Tammy D.; Gail Jones, M.

    2017-07-01

    As science grows in complexity, science teachers face an increasing challenge of helping students interpret models that represent complex science systems. Little is known about how teachers select and use models when planning lessons. This mixed methods study investigated the pedagogical approaches and visual models used by elementary in-service and preservice teachers in the development of a science lesson about a complex system (e.g., water cycle). Sixty-seven elementary in-service and 69 elementary preservice teachers completed a card sort task designed to document the types of visual models (e.g., images) that teachers choose when planning science instruction. Quantitative and qualitative analyses were conducted to analyze the card sort task. Semistructured interviews were conducted with a subsample of teachers to elicit the rationale for image selection. Results from this study showed that both experienced in-service teachers and novice preservice teachers tended to select similar models and use similar rationales for images to be used in lessons. Teachers tended to select models that were aesthetically pleasing and simple in design and illustrated specific elements of the water cycle. The results also showed that teachers were not likely to select images that represented the less obvious dimensions of the water cycle. Furthermore, teachers selected visual models more as a pedagogical tool to illustrate specific elements of the water cycle and less often as a tool to promote student learning related to complex systems.

  2. Visualization of RNA structure models within the Integrative Genomics Viewer.

    Science.gov (United States)

    Busan, Steven; Weeks, Kevin M

    2017-07-01

    Analyses of the interrelationships between RNA structure and function are increasingly important components of genomic studies. The SHAPE-MaP strategy enables accurate RNA structure probing and realistic structure modeling of kilobase-length noncoding RNAs and mRNAs. Existing tools for visualizing RNA structure models are not suitable for efficient analysis of long, structurally heterogeneous RNAs. In addition, structure models are often advantageously interpreted in the context of other experimental data and gene annotation information, for which few tools currently exist. We have developed a module within the widely used and well supported open-source Integrative Genomics Viewer (IGV) that allows visualization of SHAPE and other chemical probing data, including raw reactivities, data-driven structural entropies, and data-constrained base-pair secondary structure models, in context with linear genomic data tracks. We illustrate the usefulness of visualizing RNA structure in the IGV by exploring structure models for a large viral RNA genome, comparing bacterial mRNA structure in cells with its structure under cell- and protein-free conditions, and comparing a noncoding RNA structure modeled using SHAPE data with a base-pairing model inferred through sequence covariation analysis. © 2017 Busan and Weeks; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  3. Visual Modelling of Data Warehousing Flows with UML Profiles

    Science.gov (United States)

    Pardillo, Jesús; Golfarelli, Matteo; Rizzi, Stefano; Trujillo, Juan

    Data warehousing involves complex processes that transform source data through several stages to deliver suitable information ready to be analysed. Though many techniques for visual modelling of data warehouses from the static point of view have been devised, only few attempts have been made to model the data flows involved in a data warehousing process. Besides, each attempt was mainly aimed at a specific application, such as ETL, OLAP, what-if analysis, data mining. Data flows are typically very complex in this domain; for this reason, we argue, designers would greatly benefit from a technique for uniformly modelling data warehousing flows for all applications. In this paper, we propose an integrated visual modelling technique for data cubes and data flows. This technique is based on UML profiling; its feasibility is evaluated by means of a prototype implementation.

  4. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, P.M.; Madsen, Kristoffer H; Lund, T.E.

    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...

  5. Low-rank and sparse modeling for visual analysis

    CERN Document Server

    Fu, Yun

    2014-01-01

    This book provides a view of low-rank and sparse computing, especially approximation, recovery, representation, scaling, coding, embedding and learning among unconstrained visual data. The book includes chapters covering multiple emerging topics in this new field. It links multiple popular research fields in Human-Centered Computing, Social Media, Image Classification, Pattern Recognition, Computer Vision, Big Data, and Human-Computer Interaction. Contains an overview of the low-rank and sparse modeling techniques for visual analysis by examining both theoretical analysis and real-world applic

  6. Dynamic scene stitching driven by visual cognition model.

    Science.gov (United States)

    Zou, Li-hui; Zhang, Dezheng; Wulamu, Aziguli

    2014-01-01

    Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  7. Dynamic Scene Stitching Driven by Visual Cognition Model

    Directory of Open Access Journals (Sweden)

    Li-hui Zou

    2014-01-01

    Full Text Available Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  8. Image categorization based on spatial visual vocabulary model

    Science.gov (United States)

    Wang, Yuxin; He, Changqin; Guo, He; Feng, Zhen; Jia, Qi

    2010-08-01

    In this paper, we propose an approach to recognize scene categories by means of a novel method named spatial visual vocabulary. Firstly, we hierarchically divide images into sub regions and construct the spatial visual vocabulary by grouping the low-level features collected from every corresponding spatial sub region into a specified number of clusters using k-means algorithm. To recognize the category of a scene, the visual vocabulary distributions of all spatial sub regions are concatenated to form a global feature vector. The classification is obtained using LIBSVM, a support vector machine classifier. Our goal is to find a universal framework which is applicable to various types of features, so two kinds of features are used in the experiments: "V1-like" filters and PACT features. In almost all experimental cases, the proposed model achieves superior results. Source codes are available by email.

  9. Modelling the shape hierarchy for visually guided grasping

    Directory of Open Access Journals (Sweden)

    Omid eRezai

    2014-10-01

    Full Text Available The monkey anterior intraparietal area (AIP encodes visual information about three-dimensional object shape that is used to shape the hand for grasping. We modelled shape tuning in visual AIP neurons and its relationship with curvature and gradient information from the caudal intraparietal area (CIP. The main goal was to gain insight into the kinds of shape parameterizations that can account for AIP tuning and that are consistent with both the inputs to AIP and the role of AIP in grasping. We first experimented with superquadric shape parameters. We considered superquadrics because they occupy a role in robotics that is similar to AIP, in that superquadric fits are derived from visual input and used for grasp planning. We also experimented with an alternative shape parameterization that was based on an Isomap dimension reduction of spatial derivatives of depth (i.e. distance from the observer to the object surface. We considered an Isomap-based model because its parameters lacked discontinuities between similar shapes. When we matched the dimension of the Isomap to the number of superquadric parameters, the superquadric model fit the AIP data somewhat more closely. However, higher-dimensional Isomaps provided excellent fits. Also, we found that the Isomap parameters could be approximated much more accurately than superquadric parameters by feedforward neural networks with CIP-like inputs. We conclude that Isomaps, or perhaps alternative dimension reductions of visual inputs to AIP, provide a promising model of AIP electrophysiology data. However (in contrast with superquadrics further work is needed to test whether such shape parameterizations actually provide an effective basis for grasp control.

  10. Designing visual displays and system models for safe reactor operations

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A.

    1995-12-31

    The material presented in this paper is based on two studies involving the design of visual displays and the user`s prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator`s perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors.

  11. Eksplorasi Pose dalam Pemotretan Model Melalui Kajian Visual Relief Karmawibhangga

    Directory of Open Access Journals (Sweden)

    Noor Latif CM

    2015-10-01

    Full Text Available Karmawibhangga Relief panel located at the foot of Borobudur is a relic of the visual artifacts that contains fragments of past life with a very high historical value. 160 Karmawibhangga panels tell the reality of people's lives at the time wrapped with a moral message plight. The relief provides a lot of visual references to be excavated and reconstructed again for the benefit of the creative industries today. This research digged one small part of the masterpieces of the past through photography. Understanding visual artists who create these reliefs will be beauty in the show gestures in building a very interesting story to be re-examined. Visual communication through gestures in relief Karmawibhangga enables new assumptions about body language dialect differences to current conditions. Through model genre photography, it is very useful in connection with the development of local nuanced scientific photography. Efforts to develop the traditions and culture through new media are expected to be creative commodity with a very strong product differentiation. 

  12. Common and Innovative Visuals: A sparsity modeling framework for video.

    Science.gov (United States)

    Abdolhosseini Moghadam, Abdolreza; Kumar, Mrityunjay; Radha, Hayder

    2014-05-02

    Efficient video representation models are critical for many video analysis and processing tasks. In this paper, we present a framework based on the concept of finding the sparsest solution to model video frames. To model the spatio-temporal information, frames from one scene are decomposed into two components: (i) a common frame, which describes the visual information common to all the frames in the scene/segment, and (ii) a set of innovative frames, which depicts the dynamic behaviour of the scene. The proposed approach exploits and builds on recent results in the field of compressed sensing to jointly estimate the common frame and the innovative frames for each video segment. We refer to the proposed modeling framework by CIV (Common and Innovative Visuals). We show how the proposed model can be utilized to find scene change boundaries and extend CIV to videos from multiple scenes. Furthermore, the proposed model is robust to noise and can be used for various video processing applications without relying on motion estimation and detection or image segmentation. Results for object tracking, video editing (object removal, inpainting) and scene change detection are presented to demonstrate the efficiency and the performance of the proposed model.

  13. The marmoset monkey as a model for visual neuroscience

    Science.gov (United States)

    Mitchell, Jude F.; Leopold, David A.

    2015-01-01

    The common marmoset (Callithrix jacchus) has been valuable as a primate model in biomedical research. Interest in this species has grown recently, in part due to the successful demonstration of transgenic marmosets. Here we examine the prospects of the marmoset model for visual neuroscience research, adopting a comparative framework to place the marmoset within a broader evolutionary context. The marmoset’s small brain bears most of the organizational features of other primates, and its smooth surface offers practical advantages over the macaque for areal mapping, laminar electrode penetration, and two-photon and optical imaging. Behaviorally, marmosets are more limited at performing regimented psychophysical tasks, but do readily accept the head restraint that is necessary for accurate eye tracking and neurophysiology, and can perform simple discriminations. Their natural gaze behavior closely resembles that of other primates, with a tendency to focus on objects of social interest including faces. Their immaturity at birth and routine twinning also makes them ideal for the study of postnatal visual development. These experimental factors, together with the theoretical advantages inherent in comparing anatomy, physiology, and behavior across related species, make the marmoset an excellent model for visual neuroscience. PMID:25683292

  14. Modeling and Visualization of Human Activities for Multicamera Networks

    Directory of Open Access Journals (Sweden)

    Aswin C. Sankaranarayanan

    2009-01-01

    Full Text Available Multicamera networks are becoming complex involving larger sensing areas in order to capture activities and behavior that evolve over long spatial and temporal windows. This necessitates novel methods to process the information sensed by the network and visualize it for an end user. In this paper, we describe a system for modeling and on-demand visualization of activities of groups of humans. Using the prior knowledge of the 3D structure of the scene as well as camera calibration, the system localizes humans as they navigate the scene. Activities of interest are detected by matching models of these activities learnt a priori against the multiview observations. The trajectories and the activity index for each individual summarize the dynamic content of the scene. These are used to render the scene with virtual 3D human models that mimic the observed activities of real humans. In particular, the rendering framework is designed to handle large displays with a cluster of GPUs as well as reduce the cognitive dissonance by rendering realistic weather effects and illumination. We envision use of this system for immersive visualization as well as summarization of videos that capture group behavior.

  15. Interactive Visualizations of Complex Seismic Data and Models

    Science.gov (United States)

    Chai, C.; Ammon, C. J.; Maceira, M.; Herrmann, R. B.

    2016-12-01

    The volume and complexity of seismic data and models have increased dramatically thanks to dense seismic station deployments and advances in data modeling and processing. Seismic observations such as receiver functions and surface-wave dispersion are multidimensional: latitude, longitude, time, amplitude and latitude, longitude, period, and velocity. Three-dimensional seismic velocity models are characterized with three spatial dimensions and one additional dimension for the speed. In these circumstances, exploring the data and models and assessing the data fits is a challenge. A few professional packages are available to visualize these complex data and models. However, most of these packages rely on expensive commercial software or require a substantial time investment to master, and even when that effort is complete, communicating the results to others remains a problem. A traditional approach during the model interpretation stage is to examine data fits and model features using a large number of static displays. Publications include a few key slices or cross-sections of these high-dimensional data, but this prevents others from directly exploring the model and corresponding data fits. In this presentation, we share interactive visualization examples of complex seismic data and models that are based on open-source tools and are easy to implement. Model and data are linked in an intuitive and informative web-browser based display that can be used to explore the model and the features in the data that influence various aspects of the model. We encode the model and data into HTML files and present high-dimensional information using two approaches. The first uses a Python package to pack both data and interactive plots in a single file. The second approach uses JavaScript, CSS, and HTML to build a dynamic webpage for seismic data visualization. The tools have proven useful and led to deeper insight into 3D seismic models and the data that were used to construct them

  16. Progressive Learning of Topic Modeling Parameters: A Visual Analytics Framework.

    Science.gov (United States)

    El-Assady, Mennatallah; Sevastjanova, Rita; Sperrle, Fabian; Keim, Daniel; Collins, Christopher

    2018-01-01

    Topic modeling algorithms are widely used to analyze the thematic composition of text corpora but remain difficult to interpret and adjust. Addressing these limitations, we present a modular visual analytics framework, tackling the understandability and adaptability of topic models through a user-driven reinforcement learning process which does not require a deep understanding of the underlying topic modeling algorithms. Given a document corpus, our approach initializes two algorithm configurations based on a parameter space analysis that enhances document separability. We abstract the model complexity in an interactive visual workspace for exploring the automatic matching results of two models, investigating topic summaries, analyzing parameter distributions, and reviewing documents. The main contribution of our work is an iterative decision-making technique in which users provide a document-based relevance feedback that allows the framework to converge to a user-endorsed topic distribution. We also report feedback from a two-stage study which shows that our technique results in topic model quality improvements on two independent measures.

  17. ARTISTIC VISUALIZATION OF TRAJECTORY DATA USING CLOUD MODEL

    Directory of Open Access Journals (Sweden)

    T. Wu

    2017-09-01

    Full Text Available Rapid advance of location acquisition technologies boosts the generation of trajectory data, which track the traces of moving objects. A trajectory is typically represented by a sequence of timestamped geographical locations. Data visualization is an efficient means to represent distributions and structures of datasets and reveal hidden patterns in the data. In this paper, we explore a cloud model-based method for the generation of stylized renderings of trajectory data. The artistic visualizations of the proposed method do not have the goal to allow for data mining tasks or others but instead show the aesthetic effect of the traces of moving objects in a distorted manner. The techniques used to create the images of traces of moving objects include the uncertain line using extended cloud model, stroke-based rendering of geolocation in varying styles, and stylistic shading with aesthetic effects for print or electronic displays, as well as various parameters to be further personalized. The influence of different parameters on the aesthetic qualities of various painted images is investigated, including step size, types of strokes, colour modes, and quantitative comparisons using four aesthetic measures are also involved into the experiment. The experimental results suggest that the proposed method is with advantages of uncertainty, simplicity and effectiveness, and it would inspire professional graphic designers and amateur users who may be interested in playful and creative exploration of artistic visualization of trajectory data.

  18. Artistic Visualization of Trajectory Data Using Cloud Model

    Science.gov (United States)

    Wu, T.; Zhou, Y.; Zhang, L.

    2017-09-01

    Rapid advance of location acquisition technologies boosts the generation of trajectory data, which track the traces of moving objects. A trajectory is typically represented by a sequence of timestamped geographical locations. Data visualization is an efficient means to represent distributions and structures of datasets and reveal hidden patterns in the data. In this paper, we explore a cloud model-based method for the generation of stylized renderings of trajectory data. The artistic visualizations of the proposed method do not have the goal to allow for data mining tasks or others but instead show the aesthetic effect of the traces of moving objects in a distorted manner. The techniques used to create the images of traces of moving objects include the uncertain line using extended cloud model, stroke-based rendering of geolocation in varying styles, and stylistic shading with aesthetic effects for print or electronic displays, as well as various parameters to be further personalized. The influence of different parameters on the aesthetic qualities of various painted images is investigated, including step size, types of strokes, colour modes, and quantitative comparisons using four aesthetic measures are also involved into the experiment. The experimental results suggest that the proposed method is with advantages of uncertainty, simplicity and effectiveness, and it would inspire professional graphic designers and amateur users who may be interested in playful and creative exploration of artistic visualization of trajectory data.

  19. SeiVis: An interactive visual subsurface modeling application

    KAUST Repository

    Hollt, Thomas

    2012-12-01

    The most important resources to fulfill today’s energy demands are fossil fuels, such as oil and natural gas. When exploiting hydrocarbon reservoirs, a detailed and credible model of the subsurface structures is crucial in order to minimize economic and ecological risks. Creating such a model is an inverse problem: reconstructing structures from measured reflection seismics. The major challenge here is twofold: First, the structures in highly ambiguous seismic data are interpreted in the time domain. Second, a velocity model has to be built from this interpretation to match the model to depth measurements from wells. If it is not possible to obtain a match at all positions, the interpretation has to be updated, going back to the first step. This results in a lengthy back and forth between the different steps, or in an unphysical velocity model in many cases. This paper presents a novel, integrated approach to interactively creating subsurface models from reflection seismics. It integrates the interpretation of the seismic data using an interactive horizon extraction technique based on piecewise global optimization with velocity modeling. Computing and visualizing the effects of changes to the interpretation and velocity model on the depth-converted model on the fly enables an integrated feedback loop that enables a completely new connection of the seismic data in time domain and well data in depth domain. Using a novel joint time/depth visualization, depicting side-by-side views of the original and the resulting depth-converted data, domain experts can directly fit their interpretation in time domain to spatial ground truth data. We have conducted a domain expert evaluation, which illustrates that the presented workflow enables the creation of exact subsurface models much more rapidly than previous approaches. © 2012 IEEE.

  20. Extension of a human visual system model for display simulation

    Science.gov (United States)

    Marchessoux, Cédric; Rombaut, Alexis; Kimpe, Tom; Vermeulen, Brecht; Demeester, Piet

    2008-02-01

    In the context of medical display validation, a simulation chain has been developed to facilitate display design and image quality validation. One important part is the human visual observer model to quantify the quality perception of the simulated images. Since several years, multiple research groups are modeling the various aspects of human perception to integrate them in a complete Human Visual System (HVS) and developing visible image difference metrics. In our framework, the JNDmetrix is used. It reflects the human subjective assessment of images or video fidelity. Nevertheless, the system is limited and not suitable for our accurate simulations. There is a limitation to RGB 8 bits integer images and the model takes into account display parameters like gamma, black offset, ambient light... It needs to be extended. The solutions proposed to extend the HVS model are: precision enhancement to overcome the 8 bit limit, color space conversion between XYZ and RGB and adaptation to the display parameters. The preprocessing does not introduce any kind of perceived distortion caused for example by precision enhancement. With this extension the model is used in a daily basis in the display simulation chain.

  1. 3D shape modeling by integration visual and tactile cues

    Science.gov (United States)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2015-10-01

    With the progress in CAD (Computer Aided Design) systems, many mechanical components can be designed efficiently with high precision. But, such a system is unfit for some organic shapes, for example, a toy. In this paper, an easy way to dealing with such shapes is presented, combing visual perception with tangible interaction. The method is divided into three phases: two tangible interaction phases and one visual reconstruction. In the first tangible phase, a clay model is used to represent the raw shape, and the designer can change the shape intuitively with his hands. Then the raw shape is scanned into a digital volume model through a low cost vision system. In the last tangible phase, a desktop haptic device from SensAble is used to refine the scanned volume model and convert it into a surface model. A physical clay model and a virtual clay mode are all used in this method to deal with the main shape and the details respectively, and the vision system is used to bridge the two tangible phases. The vision reconstruction system is only made of a camera to acquire raw shape through shape from silhouettes method. All of the systems are installed on a single desktop, make it convenient for designers. The vision system details and a design example are presented in the papers.

  2. An Integrated Biomechanical Model for Microgravity-Induced Visual Impairment

    Science.gov (United States)

    Nelson, Emily S.; Best, Lauren M.; Myers, Jerry G.; Mulugeta, Lealem

    2012-01-01

    When gravitational unloading occurs upon entry to space, astronauts experience a major shift in the distribution of their bodily fluids, with a net headward movement. Measurements have shown that intraocular pressure spikes, and there is a strong suspicion that intracranial pressure also rises. Some astronauts in both short- and long-duration spaceflight develop visual acuity changes, which may or may not reverse upon return to earth gravity. To date, of the 36 U.S. astronauts who have participated in long-duration space missions on the International Space Station, 15 crew members have developed minor to severe visual decrements and anatomical changes. These ophthalmic changes include hyperopic shift, optic nerve distension, optic disc edema, globe flattening, choroidal folds, and elevated cerebrospinal fluid pressure. In order to understand the physical mechanisms behind these phenomena, NASA is developing an integrated model that appropriately captures whole-body fluids transport through lumped-parameter models for the cerebrospinal and cardiovascular systems. This data feeds into a finite element model for the ocular globe and retrobulbar subarachnoid space through time-dependent boundary conditions. Although tissue models and finite element representations of the corneo-scleral shell, retina, choroid and optic nerve head have been integrated to study pathological conditions such as glaucoma, the retrobulbar subarachnoid space behind the eye has received much less attention. This presentation will describe the development and scientific foundation of our holistic model.

  3. Towards computer-based perception by modeling visual perception : A probalistic theory

    NARCIS (Netherlands)

    Ciftcioglu, O.; Bittermann, M.; Sariyildiz, S.

    2006-01-01

    Studies on computer-based perception by vision modelling are described. The visual perception is mathematically modelled where the model receives and interprets visual data from the environment. The perception is defined in probabilistic terms so that it is in the same way quantified. Human visual

  4. Scientific Visualization & Modeling for Earth Systems Science Education

    Science.gov (United States)

    Chaudhury, S. Raj; Rodriguez, Waldo J.

    2003-01-01

    Providing research experiences for undergraduate students in Earth Systems Science (ESS) poses several challenges at smaller academic institutions that might lack dedicated resources for this area of study. This paper describes the development of an innovative model that involves students with majors in diverse scientific disciplines in authentic ESS research. In studying global climate change, experts typically use scientific visualization techniques applied to remote sensing data collected by satellites. In particular, many problems related to environmental phenomena can be quantitatively addressed by investigations based on datasets related to the scientific endeavours such as the Earth Radiation Budget Experiment (ERBE). Working with data products stored at NASA's Distributed Active Archive Centers, visualization software specifically designed for students and an advanced, immersive Virtual Reality (VR) environment, students engage in guided research projects during a structured 6-week summer program. Over the 5-year span, this program has afforded the opportunity for students majoring in biology, chemistry, mathematics, computer science, physics, engineering and science education to work collaboratively in teams on research projects that emphasize the use of scientific visualization in studying the environment. Recently, a hands-on component has been added through science student partnerships with school-teachers in data collection and reporting for the GLOBE Program (GLobal Observations to Benefit the Environment).

  5. Reading visually embodied meaning from the brain: Visually grounded computational models decode visual-object mental imagery induced by written text.

    Science.gov (United States)

    Anderson, Andrew James; Bruni, Elia; Lopopolo, Alessandro; Poesio, Massimo; Baroni, Marco

    2015-10-15

    Embodiment theory predicts that mental imagery of object words recruits neural circuits involved in object perception. The degree of visual imagery present in routine thought and how it is encoded in the brain is largely unknown. We test whether fMRI activity patterns elicited by participants reading objects' names include embodied visual-object representations, and whether we can decode the representations using novel computational image-based semantic models. We first apply the image models in conjunction with text-based semantic models to test predictions of visual-specificity of semantic representations in different brain regions. Representational similarity analysis confirms that fMRI structure within ventral-temporal and lateral-occipital regions correlates most strongly with the image models and conversely text models correlate better with posterior-parietal/lateral-temporal/inferior-frontal regions. We use an unsupervised decoding algorithm that exploits commonalities in representational similarity structure found within both image model and brain data sets to classify embodied visual representations with high accuracy (8/10) and then extend it to exploit model combinations to robustly decode different brain regions in parallel. By capturing latent visual-semantic structure our models provide a route into analyzing neural representations derived from past perceptual experience rather than stimulus-driven brain activity. Our results also verify the benefit of combining multimodal data to model human-like semantic representations. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. An open science approach to modeling and visualizing ...

    Science.gov (United States)

    It is expected that cyanobacteria blooms will increase in frequency, duration, and severity as inputs of nutrients increase and the impacts of climate change are realized. Partly in response to this, federal, state, and local entities have ramped up efforts to better understand blooms which has resulted in new life for old datasets, new monitoring programs, and novel uses for non-traditional sources of data. To fully benefit from these datasets, it is also imperative that the full body of work including data, code, and manuscripts be openly available (i.e., open science). This presentation will provide several examples of our work which occurs at the intersection of open science and research on cyanobacetria blooms in lakes and ponds. In particular we will discuss 1) why open science is particularly important for environmental human health issues; 2) the lakemorpho and elevatr R packages and how we use those to model lake morphometry; 3) Shiny server applications to visualize data collected as part of the Cyanobacteria Monitoring Collaborative; and 4) distribution of our research and models via open access publications and as R packages on GitHub. Modelling and visualizing information on cyanobacteria blooms is important as it provides estimates of the extent of potential problems associated with these blooms. Furthermore, conducting this work in the open allows others to access our code, data, and results. In turn, this allows for a greater impact because the

  7. A review of visual MODFLOW applications in groundwater modelling

    Science.gov (United States)

    Hariharan, V.; Shankar, M. Uma

    2017-11-01

    Visual MODLOW is a Graphical User Interface for the USGS MODFLOW. It is a commercial software that is popular among the hydrogeologists for its user-friendly features. The software is mainly used for Groundwater flow and contaminant transport models under different conditions. This article is intended to review the versatility of its applications in groundwater modelling for the last 22 years. Agriculture, airfields, constructed wetlands, climate change, drought studies, Environmental Impact Assessment (EIA), landfills, mining operations, river and flood plain monitoring, salt water intrusion, soil profile surveys, watershed analyses, etc., are the areas where the software has been reportedly used till the current date. The review will provide a clarity on the scope of the software in groundwater modelling and research.

  8. A Spatial Lattice Model Applied for Meteorological Visualization and Analysis

    Directory of Open Access Journals (Sweden)

    Mingyue Lu

    2017-03-01

    Full Text Available Meteorological information has obvious spatial-temporal characteristics. Although it is meaningful to employ a geographic information system (GIS to visualize and analyze the meteorological information for better identification and forecasting of meteorological weather so as to reduce the meteorological disaster loss, modeling meteorological information based on a GIS is still difficult because meteorological elements generally have no stable shape or clear boundary. To date, there are still few GIS models that can satisfy the requirements of both meteorological visualization and analysis. In this article, a spatial lattice model based on sampling particles is proposed to support both the representation and analysis of meteorological information. In this model, a spatial sampling particle is regarded as the basic element that contains the meteorological information, and the location where the particle is placed with the time mark. The location information is generally represented using a point. As these points can be extended to a surface in two dimensions and a voxel in three dimensions, if these surfaces and voxels can occupy a certain space, then this space can be represented using these spatial sampling particles with their point locations and meteorological information. In this case, the full meteorological space can then be represented by arranging numerous particles with their point locations in a certain structure and resolution, i.e., the spatial lattice model, and extended at a higher resolution when necessary. For practical use, the meteorological space is logically classified into three types of spaces, namely the projection surface space, curved surface space, and stereoscopic space, and application-oriented spatial lattice models with different organization forms of spatial sampling particles are designed to support the representation, inquiry, and analysis of meteorological information within the three types of surfaces. Cases

  9. Visualization of protein folding funnels in lattice models.

    Science.gov (United States)

    Oliveira, Antonio B; Fatore, Francisco M; Paulovich, Fernando V; Oliveira, Osvaldo N; Leite, Vitor B P

    2014-01-01

    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.

  10. 3D Building Evacuation Route Modelling and Visualization

    Science.gov (United States)

    Chan, W.; Armenakis, C.

    2014-11-01

    The most common building evacuation approach currently applied is to have evacuation routes planned prior to these emergency events. These routes are usually the shortest and most practical path from each building room to the closest exit. The problem with this approach is that it is not adaptive. It is not responsively configurable relative to the type, intensity, or location of the emergency risk. Moreover, it does not provide any information to the affected persons or to the emergency responders while not allowing for the review of simulated hazard scenarios and alternative evacuation routes. In this paper we address two main tasks. The first is the modelling of the spatial risk caused by a hazardous event leading to choosing the optimal evacuation route for a set of options. The second is to generate a 3D visual representation of the model output. A multicriteria decision making (MCDM) approach is used to model the risk aiming at finding the optimal evacuation route. This is achieved by using the analytical hierarchy process (AHP) on the criteria describing the different alternative evacuation routes. The best route is then chosen to be the alternative with the least cost. The 3D visual representation of the model displays the building, the surrounding environment, the evacuee's location, the hazard location, the risk areas and the optimal evacuation pathway to the target safety location. The work has been performed using ESRI's ArcGIS. Using the developed models, the user can input the location of the hazard and the location of the evacuee. The system then determines the optimum evacuation route and displays it in 3D.

  11. 3D-printer visualization of neuron models

    Directory of Open Access Journals (Sweden)

    Robert A McDougal

    2015-06-01

    Full Text Available Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the wireframe tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG. We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases.

  12. 3D-printer visualization of neuron models.

    Science.gov (United States)

    McDougal, Robert A; Shepherd, Gordon M

    2015-01-01

    Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases.

  13. A Digital Simulation of Psychological Correlates of a Model of the Human Visual System.

    Science.gov (United States)

    model’s ability to exhibit Gestalt grouping principles and visual illusions. Psychological correlates were obtained by comparing human visual performance...to the computer model’s performance; the correlation factors were high. Patterns containing Gestalt grouping principles and various visual illusions

  14. Creating Shared Mental Models: The Support of Visual Language

    Science.gov (United States)

    Landman, Renske B.; van den Broek, Egon L.; Gieskes, José F. B.

    Cooperative design involves multiple stakeholders that often hold different ideas of the problem, the ways to solve it, and to its solutions (i.e., mental models; MM). These differences can result in miscommunication, misunderstanding, slower decision making processes, and less chance on cooperative decisions. In order to facilitate the creation of a shared mental model (sMM), visual languages (VL) are often used. However, little scientific foundation is behind this choice. To determine whether or not this gut feeling is justified, a research was conducted in which various stakeholders had to cooperatively redesign a process chain, with and without VL. To determine whether or not a sMM was created, scores on agreement in individual MM, communication, and cooperation were analyzed. The results confirmed the assumption that VL can indeed play an important role in the creation of sMM and, hence, can aid the processes of cooperative design and engineering.

  15. Visualization of Nonlinear Classification Models in Neuroimaging - Signed Sensitivity Maps

    DEFF Research Database (Denmark)

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

    2012-01-01

    visualization. Specifically we focus on the generation of summary maps of a nonlinear classifier, that reveal how the classifier works in different parts of the input domain. Each of the maps includes sign information, unlike earlier related methods. The sign information allows the researcher to assess in which......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...

  16. Visual Representations Of Non-Separable Spatiotemporal Covariance Models

    Science.gov (United States)

    Kolovos, A.; Christakos, G.; Hristopulos, D. T.; Serre, M. L.

    2003-12-01

    Natural processes that relate to climatic variability (such as air circulation, air-water and air-soil energy exchanges) contain inherently stochastic components. Spatiotemporal random fields are frequently employed to model such processes and deal with the uncertainty involved. Covariance functions are statistical tools that are used to express correlations between process values across space and time. This work focuses on a review and visual representation of a series of useful covariance models that have been introduced in the Modern Spatiotemporal Geostatistics literature. Some of their important features are examined and their application can significantly improve the interpretation of space/time correlations that affect the long-term climatic evolution both on a local or a global scale.

  17. Robustness Analysis of Visual Question Answering Models by Basic Questions

    KAUST Repository

    Huang, Jia-Hong

    2017-11-01

    Visual Question Answering (VQA) models should have both high robustness and accuracy. Unfortunately, most of the current VQA research only focuses on accuracy because there is a lack of proper methods to measure the robustness of VQA models. There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the ranked basic questions, with similarity scores, of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question about the given image. We claim that a robust VQA model is one, whose performance is not changed much when related basic questions as also made available to it as input. We formulate the basic questions generation problem as a LASSO optimization, and also propose a large scale Basic Question Dataset (BQD) and Rscore (novel robustness measure), for analyzing the robustness of VQA models. We hope our BQD will be used as a benchmark for to evaluate the robustness of VQA models, so as to help the community build more robust and accurate VQA models.

  18. Robustness Analysis of Visual QA Models by Basic Questions

    KAUST Repository

    Huang, Jia-Hong

    2017-09-14

    Visual Question Answering (VQA) models should have both high robustness and accuracy. Unfortunately, most of the current VQA research only focuses on accuracy because there is a lack of proper methods to measure the robustness of VQA models. There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the ranked basic questions, with similarity scores, of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question about the given image. We claim that a robust VQA model is one, whose performance is not changed much when related basic questions as also made available to it as input. We formulate the basic questions generation problem as a LASSO optimization, and also propose a large scale Basic Question Dataset (BQD) and Rscore (novel robustness measure), for analyzing the robustness of VQA models. We hope our BQD will be used as a benchmark for to evaluate the robustness of VQA models, so as to help the community build more robust and accurate VQA models.

  19. Planetary subsurface investigation by 3D visualization model .

    Science.gov (United States)

    Seu, R.; Catallo, C.; Tragni, M.; Abbattista, C.; Cinquepalmi, L.

    Subsurface data analysis and visualization represents one of the main aspect in Planetary Observation (i.e. search for water or geological characterization). The data are collected by subsurface sounding radars as instruments on-board of deep space missions. These data are generally represented as 2D radargrams in the perspective of space track and z axes (perpendicular to the subsurface) but without direct correlation to other data acquisition or knowledge on the planet . In many case there are plenty of data from other sensors of the same mission, or other ones, with high continuity in time and in space and specially around the scientific sites of interest (i.e. candidate landing areas or particular scientific interesting sites). The 2D perspective is good to analyse single acquisitions and to perform detailed analysis on the returned echo but are quite useless to compare very large dataset as now are available on many planets and moons of solar system. The best way is to approach the analysis on 3D visualization model generated from the entire stack of data. First of all this approach allows to navigate the subsurface in all directions and analyses different sections and slices or moreover navigate the iso-surfaces respect to a value (or interval). The last one allows to isolate one or more iso-surfaces and remove, in the visualization mode, other data not interesting for the analysis; finally it helps to individuate the underground 3D bodies. Other aspect is the needs to link the on-ground data, as imaging, to the underground one by geographical and context field of view.

  20. Stochastic sensitivity of a bistable energy model for visual perception

    Science.gov (United States)

    Pisarchik, Alexander N.; Bashkirtseva, Irina; Ryashko, Lev

    2017-01-01

    Modern trends in physiology, psychology and cognitive neuroscience suggest that noise is an essential component of brain functionality and self-organization. With adequate noise the brain as a complex dynamical system can easily access different ordered states and improve signal detection for decision-making by preventing deadlocks. Using a stochastic sensitivity function approach, we analyze how sensitive equilibrium points are to Gaussian noise in a bistable energy model often used for qualitative description of visual perception. The probability distribution of noise-induced transitions between two coexisting percepts is calculated at different noise intensity and system stability. Stochastic squeezing of the hysteresis range and its transition from positive (bistable regime) to negative (intermittency regime) are demonstrated as the noise intensity increases. The hysteresis is more sensitive to noise in the system with higher stability.

  1. A Computational Model of Active Vision for Visual Search in Human-Computer Interaction

    Science.gov (United States)

    2010-08-01

    interfaces. - 5 - This paper describes a computational model of visual search for HCI that integrates a contemporary understanding of visual...such as by associating jewelry with cloth) and provided visual structure to random layouts. Figure 10 shows a layout with semantically-cohesive

  2. Robust visual multitask tracking via composite sparse model

    Science.gov (United States)

    Jin, Bo; Jing, Zhongliang; Wang, Meng; Pan, Han

    2014-11-01

    Recently, multitask learning was applied to visual tracking by learning sparse particle representations in a joint task, which led to the so-called multitask tracking algorithm (MTT). Although MTT shows impressive tracking performances by mining the interdependencies between particles, the individual feature of each particle is underestimated. The utilized L1,q norm regularization assumes all features are shared between all particles and results in nearly identical representation coefficients in nonsparse rows. We propose a composite sparse multitask tracking algorithm (CSMTT). We develop a composite sparse model to formulate the object appearance as a combination of the shared feature component, the individual feature component, and the outlier component. The composite sparsity is achieved via the L and L1,1 norm minimization, and is optimized by the alternating direction method of multipliers, which provides a favorable reconstruction performance and an impressive computational efficiency. Moreover, a dynamical dictionary updating scheme is proposed to capture appearance changes. CSMTT is tested on real-world video sequences under various challenges, and experimental results show that the composite sparse model achieves noticeable lower reconstruction errors and higher computational speeds than traditional sparse models, and CSMTT has consistently better tracking performances against seven state-of-the-art trackers.

  3. A Model-Driven Visualization Tool for Use with Model-Based Systems Engineering Projects

    Science.gov (United States)

    Trase, Kathryn; Fink, Eric

    2014-01-01

    Model-Based Systems Engineering (MBSE) promotes increased consistency between a system's design and its design documentation through the use of an object-oriented system model. The creation of this system model facilitates data presentation by providing a mechanism from which information can be extracted by automated manipulation of model content. Existing MBSE tools enable model creation, but are often too complex for the unfamiliar model viewer to easily use. These tools do not yet provide many opportunities for easing into the development and use of a system model when system design documentation already exists. This study creates a Systems Modeling Language (SysML) Document Traceability Framework (SDTF) for integrating design documentation with a system model, and develops an Interactive Visualization Engine for SysML Tools (InVEST), that exports consistent, clear, and concise views of SysML model data. These exported views are each meaningful to a variety of project stakeholders with differing subjects of concern and depth of technical involvement. InVEST allows a model user to generate multiple views and reports from a MBSE model, including wiki pages and interactive visualizations of data. System data can also be filtered to present only the information relevant to the particular stakeholder, resulting in a view that is both consistent with the larger system model and other model views. Viewing the relationships between system artifacts and documentation, and filtering through data to see specialized views improves the value of the system as a whole, as data becomes information

  4. Integrated Visualization Environment for Science Mission Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work will provide NASA with an integrated visualization environment providing greater insight and a more intuitive representation of large technical...

  5. The float model: visualizing personal reflection in healthcare.

    Science.gov (United States)

    Aukes, Leo C; Cohen-Schotanus, Janke; Zwierstra, Rein P; Slaets, Joris Pj

    2009-05-01

    Healthcare students and practitioners need to be able to critically assess themselves and their actions in order to learn from their experiences and improve their care of patients. Students' behaviours can be directly observed and faculty can provide direct feedback on it, when necessary. But 'reflection', a mechanism for assessing one's self, is less visible and often remains an abstract notion that is difficult to understand, use, and assess. We designed an educational model to help healthcare educators and learners visualize reflection. We posit that it can provide a greater understanding of what reflection is, how it works and how to facilitate its development and use by individuals. As a metaphor we used the angler's (fisherman's) float, which to function properly must stand balanced and steady in the water. Likewise, healthcare practitioners try to maintain an upright balance to be able to learn and work effectively. The visible component of the float, the portion above the water, is the 'behaviour'. The hidden, "mental" components of the float are under water: expert thinking (a combination of 'clinical reasoning' and 'scientific thinking'), 'personal reflection', and 'unconscious thoughts'. Each of these mental components plays a role in maintaining balance in learning and working, varying with the circumstances and context. And of course, without water a float has no meaning. In the float model, the water symbolizes the organisational and cultural context in which each practitioner must learn to function. We propose that the float model can be used to reveal the interplay among clinicians' mental processes, which occur unseen "underneath the water" but subtly influence the appropriateness of the behaviour witnessed at the surface. We believe the model can help prevent errors in understanding practitioners' behaviours and their causes, such as when they blur scientific thinking and personal reflection, take reflection as a goal in and of itself, and deny

  6. Visual cognition: a new look at the two-visual systems model.

    Science.gov (United States)

    Jeannerod, M; Jacob, P

    2005-01-01

    In this paper, we argue that no valid comparison between visual representations can arise unless provision is made for three critical properties: their direction of fit, their direction of causation and the level of their conceptual content. The conceptual content in turn is a function of the level of processing. Representations arising from earlier stages of processing of visual input have very little or no conceptual content. Higher order representations get their conceptual content from the connections between visual cognition and other parts of the human cognitive system. The two other critical properties of visual representations are their mind/world direction of fit and their mind/world direction of causation. The output of the semantic processing of visual input has a full mind-to-world direction of fit and a full world-to-mind direction of causation: it visually registers the way the world is and is caused by what it represents. The output of the pragmatic processing yields information for the benefit of intentions, which clearly have a world-to-mind direction of fit and a mind-to-world direction of causation. An intention is both the representation of a goal and a cause of the transformation of a goal into a fact. These properties segregate representations specialized for perception from those specialized for action. Perception implies comparison between simultaneously represented and analyzed objects: hence, object perception presupposes the representation of spatial relationships among objects in a coordinate system independent from the perceiver. Spatial relationships carry cues for attributing meaning to an object, so that their processing is actually part of semantic processing of visual information. These considerations lead to a re-evaluation of the role of the two classical pathways of the human visual system: the ventral and the dorsal cortical pathways. The parietal lobe, which has been identified with the dorsal pathway, cannot be considered as

  7. Timing-dependent LTP and LTD in mouse primary visual cortex following different visual deprivation models

    Science.gov (United States)

    Chen, Xia; Fu, Junhong; Cheng, Wenbo; Song, Desheng; Qu, Xiaolei; Yang, Zhuo; Zhao, Kanxing

    2017-01-01

    Visual deprivation during the critical period induces long-lasting changes in cortical circuitry by adaptively modifying neuro-transmission and synaptic connectivity at synapses. Spike timing-dependent plasticity (STDP) is considered a strong candidate for experience-dependent changes. However, the visual deprivation forms that affect timing-dependent long-term potentiation(LTP) and long-term depression(LTD) remain unclear. Here, we demonstrated the temporal window changes of tLTP and tLTD, elicited by coincidental pre- and post-synaptic firing, following different modes of 6-day visual deprivation. Markedly broader temporal windows were found in robust tLTP and tLTD in the V1M of the deprived visual cortex in mice after 6-day MD and DE. The underlying mechanism for the changes seen with visual deprivation in juvenile mice using 6 days of dark exposure or monocular lid suture involves an increased fraction of NR2b-containing NMDAR and the consequent prolongation of NMDAR-mediated response duration. Moreover, a decrease in NR2A protein expression at the synapse is attributable to the reduction of the NR2A/2B ratio in the deprived cortex. PMID:28520739

  8. A mouse model of visual perceptual learning reveals alterations in neuronal coding and dendritic spine density in the visual cortex

    Directory of Open Access Journals (Sweden)

    Yan eWang

    2016-03-01

    Full Text Available Visual perceptual learning (VPL can improve spatial vision in normally sighted and visually impaired individuals. Although previous studies of humans and large animals have explored the neural basis of VPL, elucidation of the underlying cellular and molecular mechanisms remains a challenge. Owing to the advantages of molecular genetic and optogenetic manipulations, the mouse is a promising model for providing a mechanistic understanding of VPL. Here, we thoroughly evaluated the effects and properties of VPL on spatial vision in C57BL/6J mice using a two-alternative, forced-choice visual water task. Briefly, the mice underwent prolonged training at near the individual threshold of contrast or spatial frequency (SF for pattern discrimination or visual detection for 35 consecutive days. Following training, the contrast-threshold trained mice showed an 87% improvement in contrast sensitivity (CS and a 55% gain in visual acuity (VA. Similarly, the SF-threshold trained mice exhibited comparable and long-lasting improvements in VA and significant gains in CS over a wide range of SFs. Furthermore, learning largely transferred across eyes and stimulus orientations. Interestingly, learning could transfer from a pattern discrimination task to a visual detection task, but not vice versa. We validated that this VPL fully restored VA in adult amblyopic mice and old mice. Taken together, these data indicate that mice, as a species, exhibit reliable VPL. Intrinsic signal optical imaging revealed that mice with perceptual training had higher cut-off SFs in primary visual cortex (V1 than those without perceptual training. Moreover, perceptual training induced an increase in the dendritic spine density in layer 2/3 pyramidal neurons of V1. These results indicated functional and structural alterations in V1 during VPL. Overall, our VPL mouse model will provide a platform for investigating the neurobiological basis of VPL.

  9. The development of hand-centred visual representations in the primate brain: a computer modelling study using natural visual scenes.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Galeazzi

    2015-12-01

    Full Text Available Neurons that respond to visual targets in a hand-centred frame of reference have been found within various areas of the primate brain. We investigate how hand-centred visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organisation. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localised receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localised receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centred receptive fields decreased their shape selectivity and started responding to a localised region of hand-centred space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localised, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  10. Verification of Compartmental Epidemiological Models using Metamorphic Testing, Model Checking and Visual Analytics

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, Arvind [ORNL; Steed, Chad A [ORNL; Pullum, Laura L [ORNL

    2012-01-01

    Compartmental models in epidemiology are widely used as a means to model disease spread mechanisms and understand how one can best control the disease in case an outbreak of a widespread epidemic occurs. However, a significant challenge within the community is in the development of approaches that can be used to rigorously verify and validate these models. In this paper, we present an approach to rigorously examine and verify the behavioral properties of compartmen- tal epidemiological models under several common modeling scenarios including birth/death rates and multi-host/pathogen species. Using metamorphic testing, a novel visualization tool and model checking, we build a workflow that provides insights into the functionality of compartmental epidemiological models. Our initial results indicate that metamorphic testing can be used to verify the implementation of these models and provide insights into special conditions where these mathematical models may fail. The visualization front-end allows the end-user to scan through a variety of parameters commonly used in these models to elucidate the conditions under which an epidemic can occur. Further, specifying these models using a process algebra allows one to automatically construct behavioral properties that can be rigorously verified using model checking. Taken together, our approach allows for detecting implementation errors as well as handling conditions under which compartmental epidemiological models may fail to provide insights into disease spread dynamics.

  11. Adapting models of visual aesthetics for personalized content creation

    DEFF Research Database (Denmark)

    Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    This paper introduces a search-based approach to personalized content generation with respect to visual aesthetics. The approach is based on a two-step adaptation procedure where (1) the evaluation function that characterizes the content is adjusted to match the visual aesthetics of users and (2......) the content itself is optimized based on the personalized evaluation function. To test the efficacy of the approach we design fitness functions based on universal properties of visual perception, inspired by psychological and neurobiological research. Using these visual properties we generate aesthetically...... pleasing 2D game spaceships via neuroevolutionary constrained optimization and evaluate the impact of the designed visual properties on the generated spaceships. The offline generated spaceships are used as the initial population of an interactive evolution experiment in which players are asked to choose...

  12. Modeling and visualizing uncertainty in digital thematic maps

    Science.gov (United States)

    Prasad, M. S. Ganesh; Arora, M. K.; Sajith, V. K.

    2006-12-01

    Spatial data in the form of thematic maps produced from remote sensing images are widely used in many application areas such as hydrology, geology, disaster management, forestry etc. These maps inherently contain uncertainties due to various reasons. The presence of uncertainty in thematic maps degrades the quality of maps and subsequently affects the decisions based on these data. Traditional way of quantifying quality is to compute the overall accuracy of the map, which however does not depict the spatial distribution of quality of whole map. It would be more expedient to use pixel-wise uncertainty as a means of quality indicator of a thematic map. This can be achieved through a number of mathematical tools based on well known theories of probability, geo-statistics, fuzzy sets and rough sets. Information theory and theory of evidence may also be adopted in this context. Nevertheless, there are several challenges involved in characterizing and providing uncertainty information to the users through these theories. The aim of this paper is to apprise the users of remote sensing about the uncertainties present in the thematic maps and to suggest ways to adequately deal with these uncertainties through proper modeling and visualization. Quantification and proper representation of uncertainty to the users may lead to increase in their confidence in using remote sensing derived products.

  13. A Neural Network Model of the Visual Short-Term Memory

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Hansen, Lars Kai

    2009-01-01

    In this paper a neural network model of Visual Short-Term Memory (VSTM) is presented. The model links closely with Bundesen’s (1990) well-established mathematical theory of visual attention. We evaluate the model’s ability to fit experimental data from a classical whole and partial report study...

  14. Spherical model provides visual aid for cubic crystal study

    Science.gov (United States)

    Bacigalupi, R. J.; Spakowski, A. E.

    1965-01-01

    Transparent sphere of polymethylmethacrylate with major zones and poles of cubic crystals is used to make crystallographic visualizations and to interpret Laue X ray diffraction of single cubic crystals.

  15. Task-Difficulty Homeostasis in Car Following Models: Experimental Validation Using Self-Paced Visual Occlusion

    National Research Council Canada - National Science Library

    Pekkanen, Jami; Lappi, Otto; Itkonen, Teemu H; Summala, Heikki

    2017-01-01

    ...) model, by dynamically changing driving parameters as function of driver capability. We examined assumptions of these models experimentally using a self-paced visual occlusion paradigm in a simulated car following task...

  16. Visinets: a web-based pathway modeling and dynamic visualization tool

    National Research Council Canada - National Science Library

    Spychala, Jozef; Spychala, Pawel; Gomez, Shawn; Weinreb, Gabriel E

    2015-01-01

    In this report we describe a novel graphically oriented method for pathway modeling and a software package that allows for both modeling and visualization of biological networks in a user-friendly format...

  17. Visinets: A Web-Based Pathway Modeling and Dynamic Visualization Tool: e0123773

    National Research Council Canada - National Science Library

    Jozef Spychala; Pawel Spychala; Shawn Gomez; Gabriel E Weinreb

    2015-01-01

      In this report we describe a novel graphically oriented method for pathway modeling and a software package that allows for both modeling and visualization of biological networks in a user-friendly format...

  18. Digital representations of the real world how to capture, model, and render visual reality

    CERN Document Server

    Magnor, Marcus A; Sorkine-Hornung, Olga; Theobalt, Christian

    2015-01-01

    Create Genuine Visual Realism in Computer Graphics Digital Representations of the Real World: How to Capture, Model, and Render Visual Reality explains how to portray visual worlds with a high degree of realism using the latest video acquisition technology, computer graphics methods, and computer vision algorithms. It explores the integration of new capture modalities, reconstruction approaches, and visual perception into the computer graphics pipeline.Understand the Entire Pipeline from Acquisition, Reconstruction, and Modeling to Realistic Rendering and ApplicationsThe book covers sensors fo

  19. Modelling auditory attention: Insights from the Theory of Visual Attention (TVA)

    DEFF Research Database (Denmark)

    Roberts, K. L.; Andersen, Tobias; Kyllingsbæk, Søren

    We report initial progress towards creating an auditory analogue of a mathematical model of visual attention: the ‘Theory of Visual Attention’ (TVA; Bundesen, 1990). TVA is one of the best established models of visual attention. It assumes that visual stimuli are initially processed in parallel...... to the data produces the following parameters: the minimum amount of information required for target identification (t0); the rate at which information is encoded, assuming an exponential function (v); the relative attentional weight to targets versus distractors (α); and the capacity of VSTM (K). TVA has...

  20. DBSolve Optimum: a software package for kinetic modeling which allows dynamic visualization of simulation results

    Directory of Open Access Journals (Sweden)

    Gizzatkulov Nail M

    2010-08-01

    Full Text Available Abstract Background Systems biology research and applications require creation, validation, extensive usage of mathematical models and visualization of simulation results by end-users. Our goal is to develop novel method for visualization of simulation results and implement it in simulation software package equipped with the sophisticated mathematical and computational techniques for model development, verification and parameter fitting. Results We present mathematical simulation workbench DBSolve Optimum which is significantly improved and extended successor of well known simulation software DBSolve5. Concept of "dynamic visualization" of simulation results has been developed and implemented in DBSolve Optimum. In framework of the concept graphical objects representing metabolite concentrations and reactions change their volume and shape in accordance to simulation results. This technique is applied to visualize both kinetic response of the model and dependence of its steady state on parameter. The use of the dynamic visualization is illustrated with kinetic model of the Krebs cycle. Conclusion DBSolve Optimum is a user friendly simulation software package that enables to simplify the construction, verification, analysis and visualization of kinetic models. Dynamic visualization tool implemented in the software allows user to animate simulation results and, thereby, present them in more comprehensible mode. DBSolve Optimum and built-in dynamic visualization module is free for both academic and commercial use. It can be downloaded directly from http://www.insysbio.ru.

  1. A New Conceptual Model for Business Ecosystem Visualization and Analysis

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Hupsel Vaz

    2013-01-01

    Full Text Available This study has the objective of plotting the effects of network externalities and superstar software for the visualization and analysis of industry ecosystems. The output is made possible by gathering sales from a tracking website, associating each sale to a single consumer and by using a network visualization software. The result is a graph that shows strategic positioning of publishers and platforms, serving as a strategic tool for both academics and professionals. The approach is scalable to other industries and can be used to support analysis on mergers, acquisitions and alliances.

  2. Modelling fast forms of visual neural plasticity using a modified second-order motion energy model.

    Science.gov (United States)

    Pavan, Andrea; Contillo, Adriano; Mather, George

    2014-12-01

    The Adelson-Bergen motion energy sensor is well established as the leading model of low-level visual motion sensing in human vision. However, the standard model cannot predict adaptation effects in motion perception. A previous paper Pavan et al.(Journal of Vision 10:1-17, 2013) presented an extension to the model which uses a first-order RC gain-control circuit (leaky integrator) to implement adaptation effects which can span many seconds, and showed that the extended model's output is consistent with psychophysical data on the classic motion after-effect. Recent psychophysical research has reported adaptation over much shorter time periods, spanning just a few hundred milliseconds. The present paper further extends the sensor model to implement rapid adaptation, by adding a second-order RC circuit which causes the sensor to require a finite amount of time to react to a sudden change in stimulation. The output of the new sensor accounts accurately for psychophysical data on rapid forms of facilitation (rapid visual motion priming, rVMP) and suppression (rapid motion after-effect, rMAE). Changes in natural scene content occur over multiple time scales, and multi-stage leaky integrators of the kind proposed here offer a computational scheme for modelling adaptation over multiple time scales.

  3. Visual reconciliation of alternative similarity spaces in climate modeling

    Science.gov (United States)

    J Poco; A Dasgupta; Y Wei; William Hargrove; C.R. Schwalm; D.N. Huntzinger; R Cook; E Bertini; C.T. Silva

    2015-01-01

    Visual data analysis often requires grouping of data objects based on their similarity. In many application domains researchers use algorithms and techniques like clustering and multidimensional scaling to extract groupings from data. While extracting these groups using a single similarity criteria is relatively straightforward, comparing alternative criteria poses...

  4. Testing a Conceptual Change Model Framework for Visual Data

    Science.gov (United States)

    Finson, Kevin D.; Pedersen, Jon E.

    2015-01-01

    An emergent data analysis technique was employed to test the veracity of a conceptual framework constructed around visual data use and instruction in science classrooms. The framework incorporated all five key components Vosniadou (2007a, 2007b) described as existing in a learner's schema: framework theory, presuppositions, conceptual domains,…

  5. Relevance Theory as model for analysing visual and multimodal communication

    NARCIS (Netherlands)

    Forceville, C.; Machin, D.

    2014-01-01

    Elaborating on my earlier work (Forceville 1996: chapter 5, 2005, 2009; see also Yus 2008), I will here sketch how discussions of visual and multimodal discourse can be embedded in a more general theory of communication and cognition: Sperber and Wilson’s Relevance Theory/RT (Sperber and Wilson

  6. Spatial Visualization Ability and Impact of Drafting Models: A Quasi Experimental Study

    Science.gov (United States)

    Katsioloudis, Petros J.; Jovanovic, Vukica

    2014-01-01

    A quasi experimental study was done to determine significant positive effects among three different types of visual models and to identify whether any individual type or combination contributed towards a positive increase of spatial visualization ability for students in engineering technology courses. In particular, the study compared the use of…

  7. How Spatial Abilities and Dynamic Visualizations Interplay When Learning Functional Anatomy with 3D Anatomical Models

    Science.gov (United States)

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material…

  8. [Analytical model of readaptation of the human visual system after light exposure].

    Science.gov (United States)

    Naumov, N D

    2003-01-01

    The process of readaptation of the human visual system is considered as the behavior of a follow-up system, with the brightness of the background being the control signal. The times of recovery of visual acuity calculated by the model are compared with the experimental data.

  9. The Effects of Solid Modeling and Visualization on Technical Problem Solving

    Science.gov (United States)

    Koch, Douglas

    2011-01-01

    The purpose of this study was to determine whether or not the use of solid modeling software increases participants' success in solving a specified technical problem and how visualization affects their ability to solve a technical problem. Specifically, the study sought to determine if (a) students' visualization skills affect their problem…

  10. Adapting the Theory of Visual Attention (TVA) to model auditory attention

    DEFF Research Database (Denmark)

    Roberts, Katherine L.; Andersen, Tobias; Kyllingsbæk, Søren

    Mathematical and computational models have provided useful insights into normal and impaired visual attention, but less progress has been made in modelling auditory attention. We are developing a Theory of Auditory Attention (TAA), based on an influential visual model, the Theory of Visual...... the auditory data, producing good estimates of the rate at which information is encoded (C), the minimum exposure duration required for processing to begin (t0), and the relative attentional weight to targets versus distractors (α). Future work will address the issue of target-distractor confusion, and extend...

  11. Visual field differences in visual word recognition can emerge purely from perceptual learning: evidence from modeling Chinese character pronunciation.

    Science.gov (United States)

    Hsiao, Janet Hui-Wen

    2011-11-01

    In Chinese orthography, a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters); a minority opposite arrangement also exists (PS characters). As the number of phonetic radical types is much greater than semantic radical types, in SP characters the information is skewed to the right, whereas in PS characters it is skewed to the left. Through training a computational model for SP and PS character recognition that takes into account of the locations in which the characters appear in the visual field during learning, but does not assume any fundamental hemispheric processing difference, we show that visual field differences can emerge as a consequence of the fundamental structural differences in information between SP and PS characters, as opposed to the fundamental processing differences between the two hemispheres. This modeling result is also consistent with behavioral naming performance. This work provides strong evidence that perceptual learning, i.e., the information structure of word stimuli to which the readers have long been exposed, is one of the factors that accounts for hemispheric asymmetry effects in visual word recognition. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Next Generation, 4-D Distributed Modeling and Visualization of Battlefield

    Science.gov (United States)

    2006-07-14

    is to acquire both 3D geometry and visual appearance of a scene over time, and thus essentially record a 4D movie which could be viewed afterwards...Panoramic Photogrammetry Workshop, Berlin, Germany, 2005. 82. Srikumar Ramalingam, Peter Sturm, and Suresh K. Lodha, "Towards Complete Generic Camera...ASPRS (American Society for Photogrammetry and Remote Sensing) Conference, Baltimore, Maryland, March 2005. 84. Suresh K. Lodha, Andrew Ames, Adam

  13. Realistic Avatar Eye and Head Animation Using a Neurobiological Model of Visual Attention

    National Research Council Canada - National Science Library

    Itti, L; Dhavale, N; Pighin, F

    2003-01-01

    We describe a neurobiological model of visual attention and eye/head movements in primates, and its application to the automatic animation of a realistic virtual human head watching an unconstrained...

  14. Introduction to Information Visualization (InfoVis) Techniques for Model-Based Systems Engineering

    Science.gov (United States)

    Sindiy, Oleg; Litomisky, Krystof; Davidoff, Scott; Dekens, Frank

    2013-01-01

    This paper presents insights that conform to numerous system modeling languages/representation standards. The insights are drawn from best practices of Information Visualization as applied to aerospace-based applications.

  15. Optical information for car following: the driving by visual angle (DVA) model.

    Science.gov (United States)

    Andersen, George J; Sauer, Craig W

    2007-10-01

    The present study developed and tested a model of car following by human drivers. Previous models of car following are based on 3-D parameters such as lead vehicle speed and distance information, which are not directly available to a driver. In the present paper we present the driving by visual angle (DVA) model, which is based on the visual information (visual angle and rate of change of visual angle) available to the driver. Two experiments in a driving simulator examined car-following performance in response to speed variations of a lead vehicle defined by a sum of sine wave oscillations and ramp acceleration functions. In addition, the model was applied to six driving events using real world-driving data. The model provided a good fit to car-following performance in the driving simulation studies as well as in real-world driving performance. A comparison with the advanced interactive microscopic simulator for urban and nonurban networks (AIMSUN) model, which is based on 3-D parameters, suggests that the DVA was more predictive of driver behavior in matching lead vehicle speed and distance headway. Car-following behavior can be modeled using only visual information to the driver and can produce performance more predictive of driver performance than models based on 3-D (speed or distance) information. The DVA model has applications to several traffic safety issues, including automated driving systems and traffic flow models.

  16. Sparse representation, modeling and learning in visual recognition theory, algorithms and applications

    CERN Document Server

    Cheng, Hong

    2015-01-01

    This unique text/reference presents a comprehensive review of the state of the art in sparse representations, modeling and learning. The book examines both the theoretical foundations and details of algorithm implementation, highlighting the practical application of compressed sensing research in visual recognition and computer vision. Topics and features: provides a thorough introduction to the fundamentals of sparse representation, modeling and learning, and the application of these techniques in visual recognition; describes sparse recovery approaches, robust and efficient sparse represen

  17. Visual fatigue modeling for stereoscopic video shot based on camera motion

    Science.gov (United States)

    Shi, Guozhong; Sang, Xinzhu; Yu, Xunbo; Liu, Yangdong; Liu, Jing

    2014-11-01

    As three-dimensional television (3-DTV) and 3-D movie become popular, the discomfort of visual feeling limits further applications of 3D display technology. The cause of visual discomfort from stereoscopic video conflicts between accommodation and convergence, excessive binocular parallax, fast motion of objects and so on. Here, a novel method for evaluating visual fatigue is demonstrated. Influence factors including spatial structure, motion scale and comfortable zone are analyzed. According to the human visual system (HVS), people only need to converge their eyes to the specific objects for static cameras and background. Relative motion should be considered for different camera conditions determining different factor coefficients and weights. Compared with the traditional visual fatigue prediction model, a novel visual fatigue predicting model is presented. Visual fatigue degree is predicted using multiple linear regression method combining with the subjective evaluation. Consequently, each factor can reflect the characteristics of the scene, and the total visual fatigue score can be indicated according to the proposed algorithm. Compared with conventional algorithms which ignored the status of the camera, our approach exhibits reliable performance in terms of correlation with subjective test results.

  18. A biologically inspired neural model for visual and proprioceptive integration including sensory training.

    Science.gov (United States)

    Saidi, Maryam; Towhidkhah, Farzad; Gharibzadeh, Shahriar; Lari, Abdolaziz Azizi

    2013-12-01

    Humans perceive the surrounding world by integration of information through different sensory modalities. Earlier models of multisensory integration rely mainly on traditional Bayesian and causal Bayesian inferences for single causal (source) and two causal (for two senses such as visual and auditory systems), respectively. In this paper a new recurrent neural model is presented for integration of visual and proprioceptive information. This model is based on population coding which is able to mimic multisensory integration of neural centers in the human brain. The simulation results agree with those achieved by casual Bayesian inference. The model can also simulate the sensory training process of visual and proprioceptive information in human. Training process in multisensory integration is a point with less attention in the literature before. The effect of proprioceptive training on multisensory perception was investigated through a set of experiments in our previous study. The current study, evaluates the effect of both modalities, i.e., visual and proprioceptive training and compares them with each other through a set of new experiments. In these experiments, the subject was asked to move his/her hand in a circle and estimate its position. The experiments were performed on eight subjects with proprioception training and eight subjects with visual training. Results of the experiments show three important points: (1) visual learning rate is significantly more than that of proprioception; (2) means of visual and proprioceptive errors are decreased by training but statistical analysis shows that this decrement is significant for proprioceptive error and non-significant for visual error, and (3) visual errors in training phase even in the beginning of it, is much less than errors of the main test stage because in the main test, the subject has to focus on two senses. The results of the experiments in this paper is in agreement with the results of the neural model

  19. Google SketchUp Workshop Modeling, Visualizing, and Illustrating

    CERN Document Server

    Brixius, Laurent

    2010-01-01

    Discover the secrets of the Google SketchUp with the 16 real-world professional-level projects including parks, structures, concept art, and illustration. Google SketchUp Workshop includes all the wide variety of projects that SketchUp can be used for-architectural visualization, landscape design, video game and film conception, and more. SketchUp masters in every field will get you up to speed in this agile and intuitive software and then show you the real uses with through projects in architecture, engineering, and design. * Packed with 16 real-world Go

  20. Visible light-based human visual system conceptual model

    OpenAIRE

    Prangnell, Lee

    2016-01-01

    There is a widely held belief in the digital image and video processing community, which is as follows: the Human Visual System (HVS) is more sensitive to luminance (often confused with brightness) than photon energies (often confused with chromaticity and chrominance). Passages similar to the following occur with high frequency in the peer reviewed literature and academic text books: “the HVS is much more sensitive to brightness than colour” or “the HVS is much more sensitive to luma than ch...

  1. The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes

    OpenAIRE

    Galeazzi, Juan M.; Navajas, Joaquin; Mender, Bedeho M. W.; Quian Quiroga, Rodrigo; Minini, Loredana; Stringer, Simon M.

    2016-01-01

    ABSTRACT Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw....

  2. Comprehensive Modeling and Visualization of Cardiac Anatomy and Physiology from CT Imaging and Computer Simulations.

    Science.gov (United States)

    Xiong, Guanglei; Sun, Peng; Zhou, Haoyin; Ha, Seongmin; Hartaigh, Briain O; Truong, Quynh A; Min, James K

    2017-02-01

    In clinical cardiology, both anatomy and physiology are needed to diagnose cardiac pathologies. CT imaging and computer simulations provide valuable and complementary data for this purpose. However, it remains challenging to gain useful information from the large amount of high-dimensional diverse data. The current tools are not adequately integrated to visualize anatomic and physiologic data from a complete yet focused perspective. We introduce a new computer-aided diagnosis framework, which allows for comprehensive modeling and visualization of cardiac anatomy and physiology from CT imaging data and computer simulations, with a primary focus on ischemic heart disease. The following visual information is presented: (1) Anatomy from CT imaging: geometric modeling and visualization of cardiac anatomy, including four heart chambers, left and right ventricular outflow tracts, and coronary arteries; (2) Function from CT imaging: motion modeling, strain calculation, and visualization of four heart chambers; (3) Physiology from CT imaging: quantification and visualization of myocardial perfusion and contextual integration with coronary artery anatomy; (4) Physiology from computer simulation: computation and visualization of hemodynamics (e.g., coronary blood velocity, pressure, shear stress, and fluid forces on the vessel wall). Substantially, feedback from cardiologists have confirmed the practical utility of integrating these features for the purpose of computer-aided diagnosis of ischemic heart disease.

  3. Interactive Scientific Visualization in 3D Virtual Reality Model

    Directory of Open Access Journals (Sweden)

    Filip Popovski

    2016-11-01

    Full Text Available Scientific visualization in technology of virtual reality is a graphical representation of virtual environment in the form of images or animation that can be displayed with various devices such as Head Mounted Display (HMD or monitors that can view threedimensional world. Research in real time is a desirable capability for scientific visualization and virtual reality in which we are immersed and make the research process easier. In this scientific paper the interaction between the user and objects in the virtual environment аrе in real time which gives a sense of reality to the user. Also, Quest3D VR software package is used and the movement of the user through the virtual environment, the impossibility to walk through solid objects, methods for grabbing objects and their displacement are programmed and all interactions between them will be possible. At the end some critical analysis were made on all of these techniques on various computer systems and excellent results were obtained.

  4. Visualizing and modelling complex rockfall slopes using game-engine hosted models

    Science.gov (United States)

    Ondercin, Matthew; Hutchinson, D. Jean; Harrap, Rob

    2015-04-01

    Innovations in computing in the past few decades have resulted in entirely new ways to collect 3d geological data and visualize it. For example, new tools and techniques relying on high performance computing capabilities have become widely available, allowing us to model rockfalls with more attention to complexity of the rock slope geometry and rockfall path, with significantly higher quality base data, and with more analytical options. Model results are used to design mitigation solutions, considering the potential paths of the rockfall events and the energy they impart on impacted structures. Such models are currently implemented as general-purpose GIS tools and in specialized programs. These tools are used to inspect geometrical and geomechanical data, model rockfalls, and communicate results to researchers and the larger community. The research reported here explores the notion that 3D game engines provide a high speed, widely accessible platform on which to build rockfall modelling workflows and to provide a new and accessible outreach method. Taking advantage of the in-built physics capability of the 3D game codes, and ability to handle large terrains, these models are rapidly deployed and generate realistic visualizations of rockfall trajectories. Their utility in this area is as yet unproven, but preliminary research shows that they are capable of producing results that are comparable to existing approaches. Furthermore, modelling of case histories shows that the output matches the behaviour that is observed in the field. The key advantage of game-engine hosted models is their accessibility to the general public and to people with little to no knowledge of rockfall hazards. With much of the younger generation being very familiar with 3D environments such as Minecraft, the idea of a game-like simulation is intuitive and thus offers new ways to communicate to the general public. We present results from using the Unity game engine to develop 3D voxel worlds

  5. Physically-based in silico light sheet microscopy for visualizing fluorescent brain models.

    Science.gov (United States)

    Abdellah, Marwan; Bilgili, Ahmet; Eilemann, Stefan; Markram, Henry; Schürmann, Felix

    2015-01-01

    We present a physically-based computational model of the light sheet fluorescence microscope (LSFM). Based on Monte Carlo ray tracing and geometric optics, our method simulates the operational aspects and image formation process of the LSFM. This simulated, in silico LSFM creates synthetic images of digital fluorescent specimens that can resemble those generated by a real LSFM, as opposed to established visualization methods producing visually-plausible images. We also propose an accurate fluorescence rendering model which takes into account the intrinsic characteristics of fluorescent dyes to simulate the light interaction with fluorescent biological specimen. We demonstrate first results of our visualization pipeline to a simplified brain tissue model reconstructed from the somatosensory cortex of a young rat. The modeling aspects of the LSFM units are qualitatively analysed, and the results of the fluorescence model were quantitatively validated against the fluorescence brightness equation and characteristic emission spectra of different fluorescent dyes. Modelling and simulation.

  6. Visually-salient contour detection using a V1 neural model with horizontal connections

    CERN Document Server

    Loxley, P N

    2011-01-01

    A convolution model which accounts for neural activity dynamics in the primary visual cortex is derived and used to detect visually salient contours in images. Image inputs to the model are modulated by long-range horizontal connections, allowing contextual effects in the image to determine visual saliency, i.e. line segments arranged in a closed contour elicit a larger neural response than line segments forming background clutter. The model is tested on 3 types of contour, including a line, a circular closed contour, and a non-circular closed contour. Using a modified association field to describe horizontal connections the model is found to perform well for different parameter values. For each type of contour a different facilitation mechanism is found. Operating as a feed-forward network, the model assigns saliency by increasing the neural activity of line segments facilitated by the horizontal connections. Alternatively, operating as a feedback network, the model can achieve further improvement over sever...

  7. Forest inventory and management-based visual preference models of southern pine stands

    Science.gov (United States)

    Victor A. Rudis; James H. Gramann; Edward J. Ruddell; Joanne M. Westphal

    1988-01-01

    Statistical models explaining students' ratings of photographs of within stand forest scenes were constructed for 99 forest inventory plots in east Texas pine and oak-pine forest types. Models with parameters that are sensitive to visual preference yet compatible with forest management and timber inventories are presented. The models suggest that the density of...

  8. Towards better analysis of machine learning models: A visual analytics perspective

    Directory of Open Access Journals (Sweden)

    Shixia Liu

    2017-03-01

    Full Text Available Interactive model analysis, the process of understanding, diagnosing, and refining a machine learning model with the help of interactive visualization, is very important for users to efficiently solve real-world artificial intelligence and data mining problems. Dramatic advances in big data analytics have led to a wide variety of interactive model analysis tasks. In this paper, we present a comprehensive analysis and interpretation of this rapidly developing area. Specifically, we classify the relevant work into three categories: understanding, diagnosis, and refinement. Each category is exemplified by recent influential work. Possible future research opportunities are also explored and discussed. Keywords: Interactive model analysis, Interactive visualization, Machine learning, Understanding, Diagnosis, Refinement

  9. Towards utilizing GPUs in information visualization: a model and implementation of image-space operations.

    Science.gov (United States)

    McDonnel, Bryan; Elmqvist, Niklas

    2009-01-01

    Modern programmable GPUs represent a vast potential in terms of performance and visual flexibility for information visualization research, but surprisingly few applications even begin to utilize this potential. In this paper, we conjecture that this may be due to the mismatch between the high-level abstract data types commonly visualized in our field, and the low-level floating-point model supported by current GPU shader languages. To help remedy this situation, we present a refinement of the traditional information visualization pipeline that is amenable to implementation using GPU shaders. The refinement consists of a final image-space step in the pipeline where the multivariate data of the visualization is sampled in the resolution of the current view. To concretize the theoretical aspects of this work, we also present a visual programming environment for constructing visualization shaders using a simple drag-and-drop interface. Finally, we give some examples of the use of shaders for well-known visualization techniques.

  10. Ocean Modeling and Visualization on Massively Parallel Computer

    Science.gov (United States)

    Chao, Yi; Li, P. Peggy; Wang, Ping; Katz, Daniel S.; Cheng, Benny N.

    1997-01-01

    Climate modeling is one of the grand challenges of computational science, and ocean modeling plays an important role in both understanding the current climatic conditions and predicting future climate change.

  11. VMQL: A Visual Language for Ad-Hoc Model Querying

    DEFF Research Database (Denmark)

    Störrle, Harald

    2011-01-01

    In large scale model based development, analysis level models are more like knowledge bases than engineering artifacts. Their effectiveness depends, to a large degree, on the ability of domain experts to retrieve information from them ad hoc. For large scale models, however, existing query facili...

  12. Visualization and modeling of smoke transport over landscape scales

    Science.gov (United States)

    Glenn P. Forney; William Mell

    2007-01-01

    Computational tools have been developed at the National Institute of Standards and Technology (NIST) for modeling fire spread and smoke transport. These tools have been adapted to address fire scenarios that occur in the wildland urban interface (WUI) over kilometer-scale distances. These models include the smoke plume transport model ALOFT (A Large Open Fire plume...

  13. Treatment of amblyopia in the adult: insights from a new rodent model of visual perceptual learning.

    Science.gov (United States)

    Bonaccorsi, Joyce; Berardi, Nicoletta; Sale, Alessandro

    2014-01-01

    Amblyopia is the most common form of impairment of visual function affecting one eye, with a prevalence of about 1-5% of the total world population. Amblyopia usually derives from conditions of early functional imbalance between the two eyes, owing to anisometropia, strabismus, or congenital cataract, and results in a pronounced reduction of visual acuity and severe deficits in contrast sensitivity and stereopsis. It is widely accepted that, due to a lack of sufficient plasticity in the adult brain, amblyopia becomes untreatable after the closure of the critical period in the primary visual cortex. However, recent results obtained both in animal models and in clinical trials have challenged this view, unmasking a previously unsuspected potential for promoting recovery even in adulthood. In this context, non invasive procedures based on visual perceptual learning, i.e., the improvement in visual performance on a variety of simple visual tasks following practice, emerge as particularly promising to rescue discrimination abilities in adult amblyopic subjects. This review will survey recent work regarding the impact of visual perceptual learning on amblyopia, with a special focus on a new experimental model of perceptual learning in the amblyopic rat.

  14. Treatment of amblyopia in the adult: insights from a new rodent model of visual perceptual learning

    Directory of Open Access Journals (Sweden)

    Joyce eBonaccorsi

    2014-07-01

    Full Text Available Amblyopia is the most common form of impairment of visual function affecting one eye, with a prevalence of about 1-5% of the total world population. Amblyopia usually derives from conditions of early functional imbalance between the two eyes, owing to anisometropia, strabismus, or congenital cataract, and results in a pronounced reduction of visual acuity and severe deficits in contrast sensitivity and stereopsis. It is widely accepted that, due to a lack of sufficient plasticity in the adult brain, amblyopia becomes untreatable after the closure of the critical period in the primary visual cortex. However, recent results obtained both in animal models and in clinical trials have challenged this view, unmasking a previously unsuspected potential for promoting recovery even in adulthood. In this context, non invasive procedures based on visual perceptual learning, i.e. the improvement in visual performance on a variety of simple visual tasks following practice, emerge as particularly promising to rescue discrimination abilities in adult amblyopic subjects. This review will survey recent work regarding the impact of visual perceptual learning on amblyopia, with a special focus on a new experimental model of perceptual learning in the amblyopic rat.

  15. Visualizing Dataflow Graphs of Deep Learning Models in TensorFlow.

    Science.gov (United States)

    Wongsuphasawat, Kanit; Smilkov, Daniel; Wexler, James; Wilson, Jimbo; Mane, Dandelion; Fritz, Doug; Krishnan, Dilip; Viegas, Fernanda B; Wattenberg, Martin

    2018-01-01

    We present a design study of the TensorFlow Graph Visualizer, part of the TensorFlow machine intelligence platform. This tool helps users understand complex machine learning architectures by visualizing their underlying dataflow graphs. The tool works by applying a series of graph transformations that enable standard layout techniques to produce a legible interactive diagram. To declutter the graph, we decouple non-critical nodes from the layout. To provide an overview, we build a clustered graph using the hierarchical structure annotated in the source code. To support exploration of nested structure on demand, we perform edge bundling to enable stable and responsive cluster expansion. Finally, we detect and highlight repeated structures to emphasize a model's modular composition. To demonstrate the utility of the visualizer, we describe example usage scenarios and report user feedback. Overall, users find the visualizer useful for understanding, debugging, and sharing the structures of their models.

  16. Expert-Guided Generative Topographical Modeling with Visual to Parametric Interaction.

    Directory of Open Access Journals (Sweden)

    Chao Han

    Full Text Available Introduced by Bishop et al. in 1996, Generative Topographic Mapping (GTM is a powerful nonlinear latent variable modeling approach for visualizing high-dimensional data. It has shown useful when typical linear methods fail. However, GTM still suffers from drawbacks. Its complex parameterization of data make GTM hard to fit and sensitive to slight changes in the model. For this reason, we extend GTM to a visual analytics framework so that users may guide the parameterization and assess the data from multiple GTM perspectives. Specifically, we develop the theory and methods for Visual to Parametric Interaction (V2PI with data using GTM visualizations. The result is a dynamic version of GTM that fosters data exploration. We refer to the new version as V2PI-GTM. In this paper, we develop V2PI-GTM in stages and demonstrate its benefits within the context of a text mining case study.

  17. A Transgenic Model for Learning Defects: Role of NF1 in Drosophila Visual-Spatial Learning

    Science.gov (United States)

    2008-12-01

    segments of different orientations and elevations, prior to assaying NF1 mutants. We will begin to prepare a manuscript for publication that describes...Role of NF1 in Drosophila Visual- Spatial Learning PRINCIPAL INVESTIGATOR: Frances Hannan, Ph.D. CONTRACTING...Model for Learning Defects: Role of NF1 in Drosophila Visual-Spatial Learnings 5b. GRANT NUMBER W81XWH-07-1-0436 5c. PROGRAM ELEMENT NUMBER 6

  18. Physically-based in silico light sheet microscopy for visualizing fluorescent brain models

    OpenAIRE

    Abdellah, Marwan; Bilgili, Ahmet; Eilemann, Stefan; Markram, Henry; Schürmann, Felix

    2015-01-01

    Background We present a physically-based computational model of the light sheet fluorescence microscope (LSFM). Based on Monte Carlo ray tracing and geometric optics, our method simulates the operational aspects and image formation process of the LSFM. This simulated, in silico LSFM creates synthetic images of digital fluorescent specimens that can resemble those generated by a real LSFM, as opposed to established visualization methods producing visually-plausible images. We also propose an a...

  19. Simulation and visualization of coupled hydrodynamical, chemical and biological models

    Directory of Open Access Journals (Sweden)

    Dag Slagstad

    1997-04-01

    Full Text Available This paper briefly describes the principles of hydrodynamical and ecological modelling of marine systems and how model results are presented by use of MATLAB. Two application examples are shown. One refers to modelling and simulation of the carbon vertical transport in the Greenland Sea and the other is a study on the effect of wind pattern for the invasion success of zooplankton from the Norwegian Sea into the North Sea by use of particle tracking.

  20. VisFlow - Web-based Visualization Framework for Tabular Data with a Subset Flow Model.

    Science.gov (United States)

    Yu, Bowen; Silva, Claudio T

    2017-01-01

    Data flow systems allow the user to design a flow diagram that specifies the relations between system components which process, filter or visually present the data. Visualization systems may benefit from user-defined data flows as an analysis typically consists of rendering multiple plots on demand and performing different types of interactive queries across coordinated views. In this paper, we propose VisFlow, a web-based visualization framework for tabular data that employs a specific type of data flow model called the subset flow model. VisFlow focuses on interactive queries within the data flow, overcoming the limitation of interactivity from past computational data flow systems. In particular, VisFlow applies embedded visualizations and supports interactive selections, brushing and linking within a visualization-oriented data flow. The model requires all data transmitted by the flow to be a data item subset (i.e. groups of table rows) of some original input table, so that rendering properties can be assigned to the subset unambiguously for tracking and comparison. VisFlow features the analysis flexibility of a flow diagram, and at the same time reduces the diagram complexity and improves usability. We demonstrate the capability of VisFlow on two case studies with domain experts on real-world datasets showing that VisFlow is capable of accomplishing a considerable set of visualization and analysis tasks. The VisFlow system is available as open source on GitHub.

  1. Visual plumes coastal dispersion modeling in southwest Sabah ...

    African Journals Online (AJOL)

    The travel distance (lt) is a main function of ambient current velocity (m/s) and direction. Prior to the modeling exercise, field data pertaining to ambient water quality, hydraulic characteristics and tide patterns were collected. The modeling results indicated that there was no significant change in ambient concentration for all ...

  2. The modelling of avian visual perception predicts behavioural rejection responses to foreign egg colours.

    Science.gov (United States)

    Cassey, Phillip; Honza, Marcel; Grim, Tomas; Hauber, Mark E

    2008-10-23

    How do birds tell the colours of their own and foreign eggs apart? We demonstrate that perceptual modelling of avian visual discrimination can predict behavioural rejection responses to foreign eggs in the nest of wild birds. We use a photoreceptor noise-limited colour opponent model of visual perception to evaluate its accuracy as a predictor of behavioural rates of experimental egg discrimination in the song thrush Turdus philomelos. The visual modelling of experimental and natural eggshell colours suggests that photon capture from the ultraviolet and short wavelength-sensitive cones elicits egg rejection decisions in song thrushes, while inter-clutch variation of egg coloration provides sufficient contrasts for detecting conspecific parasitism in this species. Biologically realistic sensory models provide an important tool for relating variability of behavioural responses to perceived phenotypic variation.

  3. Simple control-theoretic models of human steering activity in visually guided vehicle control

    Science.gov (United States)

    Hess, Ronald A.

    1991-01-01

    A simple control theoretic model of human steering or control activity in the lateral-directional control of vehicles such as automobiles and rotorcraft is discussed. The term 'control theoretic' is used to emphasize the fact that the model is derived from a consideration of well-known control system design principles as opposed to psychological theories regarding egomotion, etc. The model is employed to emphasize the 'closed-loop' nature of tasks involving the visually guided control of vehicles upon, or in close proximity to, the earth and to hypothesize how changes in vehicle dynamics can significantly alter the nature of the visual cues which a human might use in such tasks.

  4. Visualizing projected Climate Changes - the CMIP5 Multi-Model Ensemble

    Science.gov (United States)

    Böttinger, Michael; Eyring, Veronika; Lauer, Axel; Meier-Fleischer, Karin

    2017-04-01

    Large ensembles add an additional dimension to climate model simulations. Internal variability of the climate system can be assessed for example by multiple climate model simulations with small variations in the initial conditions or by analyzing the spread in large ensembles made by multiple climate models under common protocols. This spread is often used as a measure of uncertainty in climate projections. In the context of the fifth phase of the WCRP's Coupled Model Intercomparison Project (CMIP5), more than 40 different coupled climate models were employed to carry out a coordinated set of experiments. Time series of the development of integral quantities such as the global mean temperature change for all models visualize the spread in the multi-model ensemble. A similar approach can be applied to 2D-visualizations of projected climate changes such as latitude-longitude maps showing the multi-model mean of the ensemble by adding a graphical representation of the uncertainty information. This has been demonstrated for example with static figures in chapter 12 of the last IPCC report (AR5) using different so-called stippling and hatching techniques. In this work, we focus on animated visualizations of multi-model ensemble climate projections carried out within CMIP5 as a way of communicating climate change results to the scientific community as well as to the public. We take a closer look at measures of robustness or uncertainty used in recent publications suitable for animated visualizations. Specifically, we use the ESMValTool [1] to process and prepare the CMIP5 multi-model data in combination with standard visualization tools such as NCL and the commercial 3D visualization software Avizo to create the animations. We compare different visualization techniques such as height fields or shading with transparency for creating animated visualization of ensemble mean changes in temperature and precipitation including corresponding robustness measures. [1] Eyring, V

  5. On the Efficiency of Image Metrics for Evaluating the Visual Quality of 3D Models.

    Science.gov (United States)

    Lavoue, Guillaume; Larabi, Mohamed Chaker; Vasa, Libor

    2016-08-01

    3D meshes are deployed in a wide range of application processes (e.g., transmission, compression, simplification, watermarking and so on) which inevitably introduce geometric distortions that may alter the visual quality of the rendered data. Hence, efficient model-based perceptual metrics, operating on the geometry of the meshes being compared, have been recently introduced to control and predict these visual artifacts. However, since the 3D models are ultimately visualized on 2D screens, it seems legitimate to use images of the models (i.e., snapshots from different viewpoints) to evaluate their visual fidelity. In this work we investigate the use of image metrics to assess the visual quality of 3D models. For this goal, we conduct a wide-ranging study involving several 2D metrics, rendering algorithms, lighting conditions and pooling algorithms, as well as several mean opinion score databases. The collected data allow (1) to determine the best set of parameters to use for this image-based quality assessment approach and (2) to compare this approach to the best performing model-based metrics and determine for which use-case they are respectively adapted. We conclude by exploring several applications that illustrate the benefits of image-based quality assessment.

  6. MENCARI MODEL EVALUASI DENGAN PENDEKATAN YANG SESUAI UNTUK PENDIDIKAN DESAIN KOMUNIKASI VISUAL

    Directory of Open Access Journals (Sweden)

    Maria N D K Indrayana

    2002-01-01

    Full Text Available Visual communication design in coming years seem getting better. It can be seen by the growth of commercial advertisment in the last three years and the pers freedom make the printing media and new electronic media exist. It would make the Visual communication design proffesion is became important. In the other side%2C there is a fact that many of advertisement have been canceled because of many public critical. Because of this%2C the designer as a creatif person has to be responsible. Because of this fenomena%2C education of visual communication design in Indonesia as an institution has to make the best quality designer. The process of study is become very important. Because of that reason%2C the evaluation model with suitable approach is needed for education of visual communication design. Abstract in Bahasa Indonesia : Prospek desain komunikasi visual pada tahun-tahun mendatang tampak lebih cerah dengan fenomena kenaikan belanja iklan tiga tahun terakhir dan kebebasan pers yang memicu kelahiran banyak media cetak dan media elektronik baru. Sehingga profesi ini akan semakin berperan penting. Di pihak lain ada kenyataan ditariknya sejumlah iklan yang tengah ditayangkan karena kritik yang diterimanya%2C sehingga desainer sebagai pengolah kreatif dianggap turut bertanggung jawab . Dengan berbagai latar belakang itulah institusi pendidikan Desain Komunikasi Visual di Indonesia sebagai wadah penggodokan calon desainer dituntut untuk melahirkan desainer dengan kualitas terbaik. Maka proses studi menjadi penting. Untuk itu diperlukan model evaluasi dengan pendekatan yang sekiranya sesuai untuk pendidikan desain komunikasi visual%2C dewasa ini. evaluation model%2C education of visual communication design.

  7. An Integrated Visualization and Basic Molecular Modeling Laboratory for First-Year Undergraduate Medicinal Chemistry

    Science.gov (United States)

    Hayes, Joseph M.

    2014-01-01

    A 3D model visualization and basic molecular modeling laboratory suitable for first-year undergraduates studying introductory medicinal chemistry is presented. The 2 h practical is embedded within a series of lectures on drug design, target-drug interactions, enzymes, receptors, nucleic acids, and basic pharmacokinetics. Serving as a teaching aid…

  8. Using a human cognition model in the creation of collaborative knowledge visualizations

    Science.gov (United States)

    Green, Tera Marie; Ribarsky, William

    2008-04-01

    This paper explores the basis and usefulness of a predictive model for the architecture of data and knowledge visualizations based on human higher-cognition, including human tendencies in reasoning heuristics and cognitive biases. The strengths and weakness of would-be human and computer collaborators are explored, and a model framework is outlined and discussed.

  9. Using a Three-Dimensional Interactive Model To Teach Environmental Concepts to Visually Impaired Children.

    Science.gov (United States)

    Budd, Julia M.; LaGrow, Steven J.

    2000-01-01

    A study investigated the efficacy of using the Buddy Road Kit, an interactive, wooden model, to teach environmental concepts to 4 children with visual impairments ages 7 to 11 years old. Results indicate the model was effective in teaching environmental concepts and traffic safety to the children involved. (Contains references.) (CR)

  10. Extracting conceptual models from user stories with Visual Narrator

    NARCIS (Netherlands)

    Lucassen, Garm|info:eu-repo/dai/nl/412351366; Robeer, Marcel; Dalpiaz, Fabiano|info:eu-repo/dai/nl/369508394; van der Werf, Jan Martijn E. M.|info:eu-repo/dai/nl/36950674X; Brinkkemper, Sjaak|info:eu-repo/dai/nl/07500707X

    2017-01-01

    Extracting conceptual models from natural language requirements can help identify dependencies, redundancies, and conflicts between requirements via a holistic and easy-to-understand view that is generated from lengthy textual specifications. Unfortunately, existing approaches never gained traction

  11. Force-directed visualization for conceptual data models

    Science.gov (United States)

    Battigaglia, Andrew; Sutter, Noah

    2017-03-01

    Conceptual data models are increasingly stored in an eXtensible Markup Language (XML) format because of its portability between different systems and the ability of databases to use this format for storing data. However, when attempting to capture business or design needs, an organized graphical format is preferred in order to facilitate communication to receive as much input as possible from users and subject-matter experts. Existing methods of achieving this conversion suffer from problems of not being specific enough to capture all of the needs of conceptual data modeling and not being able to handle a large number of relationships between entities. This paper describes an implementation for a modeling solution to clearly illustrate conceptual data models stored in XML formats in well organized and structured diagrams. A force layout with several different parameters is applied to the diagram to create both compact and easily traversable relationships between entities.

  12. Integrated Visualization Environment for Science Mission Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is emphasizing the use of larger, more integrated models in conjunction with systems engineering tools and decision support systems. These tools place a...

  13. Biologically Inspired Visual Model With Preliminary Cognition and Active Attention Adjustment.

    Science.gov (United States)

    Qiao, Hong; Xi, Xuanyang; Li, Yinlin; Wu, Wei; Li, Fengfu

    2015-11-01

    Recently, many computational models have been proposed to simulate visual cognition process. For example, the hierarchical Max-Pooling (HMAX) model was proposed according to the hierarchical and bottom-up structure of V1 to V4 in the ventral pathway of primate visual cortex, which could achieve position- and scale-tolerant recognition. In our previous work, we have introduced memory and association into the HMAX model to simulate visual cognition process. In this paper, we improve our theoretical framework by mimicking a more elaborate structure and function of the primate visual cortex. We will mainly focus on the new formation of memory and association in visual processing under different circumstances as well as preliminary cognition and active adjustment in the inferior temporal cortex, which are absent in the HMAX model. The main contributions of this paper are: 1) in the memory and association part, we apply deep convolutional neural networks to extract various episodic features of the objects since people use different features for object recognition. Moreover, to achieve a fast and robust recognition in the retrieval and association process, different types of features are stored in separated clusters and the feature binding of the same object is stimulated in a loop discharge manner and 2) in the preliminary cognition and active adjustment part, we introduce preliminary cognition to classify different types of objects since distinct neural circuits in a human brain are used for identification of various types of objects. Furthermore, active cognition adjustment of occlusion and orientation is implemented to the model to mimic the top-down effect in human cognition process. Finally, our model is evaluated on two face databases CAS-PEAL-R1 and AR. The results demonstrate that our model exhibits its efficiency on visual recognition process with much lower memory storage requirement and a better performance compared with the traditional purely computational

  14. Computational Modelling of the Neural Representation of Object Shape in the Primate Ventral Visual System

    Directory of Open Access Journals (Sweden)

    Akihiro eEguchi

    2015-08-01

    Full Text Available Neurons in successive stages of the primate ventral visual pathway encode the spatial structure of visual objects. In this paper, we investigate through computer simulation how these cell firing properties may develop through unsupervised visually-guided learning. Individual neurons in the model are shown to exploit statistical regularity and temporal continuity of the visual inputs during training to learn firing properties that are similar to neurons in V4 and TEO. Neurons in V4 encode the conformation of boundary contour elements at a particular position within an object regardless of the location of the object on the retina, while neurons in TEO integrate information from multiple boundary contour elements. This representation goes beyond mere object recognition, in which neurons simply respond to the presence of a whole object, but provides an essential foundation from which the brain is subsequently able to recognise the whole object.

  15. A dual visual-local feedback model of the vergence eye movement system.

    Science.gov (United States)

    Erkelens, Casper J

    2011-09-27

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets differing in direction. Saccades are extremely fast and controlled by a local, non-visual feedback loop. Usually, we change our fixation between targets that differ in both distance and direction. Then, vergence eye movements are combined with saccades. A number of models have been proposed to explain the dynamics of saccade-related vergence movements. The models have in common that visual input is ignored for the duration of the responses. This type of control is realistic for saccades but not for vergence. Here, I present computations performed to investigate if a model using dual visual and local feedback can replace the current models. Simulations and stability analysis lead to a model that computes an estimate of target vergence instead of retinal disparity and uses this signal as the main drive. Further analysis shows that the model describes the dynamics of pure vergence responses over the full physiological range, saccade-related vergence movements, and vergence adaptation. The structure of the model leads to new hypotheses about the control of vergence.

  16. 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...

  17. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    Directory of Open Access Journals (Sweden)

    Na Wei

    2013-01-01

    Full Text Available Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport mathematical model according to gas-liquid-solid flow mechanism and large plane dunes particle transport theory.

  18. Modeling, simulation and visual analysis of crowds a multidisciplinary perspective

    CERN Document Server

    Ali, Saad; Manocha, Dinesh; Shah, Mubarak

    2013-01-01

    Over the last several years there has been a growing interest in developing computational methodologies for modeling and analyzing movements and behaviors of 'crowds' of people. This interest spans several scientific areas that includes Computer Vision, Computer Graphics, and Pedestrian Evacuation Dynamics. Despite the fact that these different scientific fields are trying to model the same physical entity (i.e. a crowd of people), research ideas have evolved independently. As a result each discipline has developed techniques and perspectives that are characteristically their own.

  19. Creating shared mental models: The support of visual language

    NARCIS (Netherlands)

    Landman, Renske B.; van den Broek, Egon; Gieskes, J.F.B.; Luo, Yuhua

    Cooperative design involves multiple stakeholders that often hold different ideas of the problem, the ways to solve it, and to its solutions (i.e., mental models; MM). These differences can result in miscommunication, misunderstanding, slower decision making processes, and less chance on cooperative

  20. Theme section: Multi-dimensional modelling, analysis and visualization

    DEFF Research Database (Denmark)

    Guilbert, Éric; Coltekin, Arzu; Antón Castro, Francesc/François

    2016-01-01

    in order to provide a meaningful representation and assist in data visualisation and mining, modelling and analysis; such as data structures allowing representation at different scalesor in different contexts of thematic information. Such issues are of importance with regard to the mission of theI SPRS...

  1. Biliary System Architecture: Experimental Models and Visualization Techniques

    Czech Academy of Sciences Publication Activity Database

    Sarnová, Lenka; Gregor, Martin

    2017-01-01

    Roč. 66, č. 3 (2017), s. 383-390 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LQ1604; GA ČR GA15-23858S Institutional support: RVO:68378050 Keywords : Biliary system * Mouse model * Cholestasis * Visualisation * Morphology Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016

  2. On Parsing Visual Sequences with the Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Harte Naomi

    2009-01-01

    Full Text Available Hidden Markov Models have been employed in many vision applications to model and identify events of interest. Their use is common in applications where HMMs are used to classify previously divided segments of video as one of a set of events being modelled. HMMs can also simultaneously segment and classify events within a continuous video, without the need for a separate first step to identify the start and end of the events. This is significantly less common. This paper is an exploration of the development of HMM frameworks for such complete event recognition. A review of how HMMs have been applied to both event classification and recognition is presented. The discussion evolves in parallel with an example of a real application in psychology for illustration. The complete videos depict sessions where candidates perform a number of different exercises under the instruction of a psychologist. The goal is to isolate portions of video containing just one of these exercises. The exercise involves rotating the head of a kneeling subject to the left, back to centre, to the right, to the centre, and repeating a number of times. By designing a HMM system to automatically isolate portions of video containing this exercise, issues such as the strategy of choice of event to be modelled, feature design and selection, as well as training and testing are reviewed. Thus this paper shows how HMMs can be more extensively applied in the domain of event recognition in video.

  3. Visualizing Decimal Multiplication with Area Models: Opportunities and Challenges

    Science.gov (United States)

    Rathouz, Margaret

    2011-01-01

    This article describes a pilot study in which pre-service elementary teachers (PSTs) used rectangular area models on base-10 grid paper to begin making sense of multiplication of decimal fractions. Although connections were made to multi-digit whole number multiplication and to the distributive property, the PSTs were challenged by interpreting…

  4. JVIEW Visualization for Virtual Airspace Modeling and Simulation

    Science.gov (United States)

    2009-04-01

    JView users. An example of a model that was developed is the RASCAL 110 aircraft used in the Characterization of the UAV Network Environment (CUNE...115 Table 5 - Aircraft / Unmanned Aerial Vehicle (UAV) Global Hawk Predator Rascal 116 Table 6 - Computer Hardware / IO

  5. A neural model of retrospective attention in visual working memory.

    Science.gov (United States)

    Bays, Paul M; Taylor, Robert

    2018-02-01

    An informative cue that directs attention to one of several items in working memory improves subsequent recall of that item. Here we examine the mechanism of this retro-cue effect using a model of short-term memory based on neural population coding. Our model describes recalled feature values as the output of an optimal decoding of spikes generated by a tuned population of neurons. This neural model provides a better account of human recall data than an influential model that assumes errors can be described as a mixture of normally distributed noise and random guesses. The retro-cue benefit is revealed to be consistent with a higher firing rate of the population encoding the cued versus uncued items, with no difference in tuning specificity. Additionally, a retro-cued item is less likely to be swapped with another item in memory, an effect that can also be explained by greater activity of the underlying population. These results provide a parsimonious account of the effects of retrospective attention on recall and demonstrate a principled method for investigating neural representations with behavioral tasks. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. A Proto-Object-Based Computational Model for Visual Saliency

    NARCIS (Netherlands)

    Yanulevskaya, V.; Uijlings, J.; Geusebroek, J.-M.; Sebe, N.; Smeulders, A.

    2013-01-01

    State-of-the-art bottom-up saliency models often assign high saliency values at or near high-contrast edges, whereas people tend to look within the regions delineated by those edges, namely the objects. To resolve this inconsistency, in this work we estimate saliency at the level of coherent image

  7. D Model Visualization Enhancements in Real-Time Game Engines

    Science.gov (United States)

    Merlo, A.; Sánchez Belenguer, C.; Vendrell Vidal, E.; Fantini, F.; Aliperta, A.

    2013-02-01

    This paper describes two procedures used to disseminate tangible cultural heritage through real-time 3D simulations providing accurate-scientific representations. The main idea is to create simple geometries (with low-poly count) and apply two different texture maps to them: a normal map and a displacement map. There are two ways to achieve models that fit with normal or displacement maps: with the former (normal maps), the number of polygons in the reality-based model may be dramatically reduced by decimation algorithms and then normals may be calculated by rendering them to texture solutions (baking). With the latter, a LOD model is needed; its topology has to be quad-dominant for it to be converted to a good quality subdivision surface (with consistent tangency and curvature all over). The subdivision surface is constructed using methodologies for the construction of assets borrowed from character animation: these techniques have been recently implemented in many entertainment applications known as "retopology". The normal map is used as usual, in order to shade the surface of the model in a realistic way. The displacement map is used to finish, in real-time, the flat faces of the object, by adding the geometric detail missing in the low-poly models. The accuracy of the resulting geometry is progressively refined based on the distance from the viewing point, so the result is like a continuous level of detail, the only difference being that there is no need to create different 3D models for one and the same object. All geometric detail is calculated in real-time according to the displacement map. This approach can be used in Unity, a real-time 3D engine originally designed for developing computer games. It provides a powerful rendering engine, fully integrated with a complete set of intuitive tools and rapid workflows that allow users to easily create interactive 3D contents. With the release of Unity 4.0, new rendering features have been added, including Direct

  8. Memikirkan Ulang Bisnis Model Berbasis Desain Komunikasi Visual

    Directory of Open Access Journals (Sweden)

    Mendiola B. Wiryawan

    2011-04-01

    Full Text Available Graphic design as an applied art started to grow side by side with the growth of many businesses that needed promotion and advertising. Although graphic design can be categorized as a service company, it cannot be directly handled the same as any other service companies. Design companies always involve two opposite poles: aesthetic vs. logic, individual vs. mass, idealism versus reality. The best way viewing a graphic design as a business entity is seeing through its business model’s side. A business model is a simple representation of the complex reality of a business. The primary purpose of a business model is to communicate business mechanism among stakeholders. The article gives insight to see components of graphic design business and their future challenge. In the future, it is expected there are more discussions about this topics so that Indonesian graphic design industry will grow in the future. 

  9. Modeling and Simulation of the Visual Effects of Colored Filters

    Science.gov (United States)

    2015-02-01

    distribution unlimited. PA Case No: TSRL-PA-2015-0065 13. SUPPLEMENTARY NOTES 14. ABSTRACT OptisWorks® commercial software add-on for SolidWorks ® was used to...component (fuel gauge) that was modeled in SolidWorks . On the left is the original bitmap image (photograph) of the gauge and on the right is a closeup...example of the SolidWorks geometry built on top of the bitmap

  10. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    OpenAIRE

    Na Wei; YingFeng Meng; Gao Li; LiPing Wan; ZhaoYang Xu; XiaoFeng Xu; YuRui Zhang

    2013-01-01

    Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport ma...

  11. Visual Analysis of Swarm and Geomagnetic Model Data

    Science.gov (United States)

    Santillan Pedrosa, Daniel; Triebnig, Gerhard

    2016-08-01

    ESA Swarm data is available for anyone to use via the virtual research platform "VirES for Swarm" (http://vires.services). A highly interactive data manipulation and retrieval interface is provided for the magnetic products of the European Space Agency (ESA) Swarm constellation mission. It includes tools for studying various Earth magnetic models and for comparing them to the Swarm satellite measurements and given solar activity levels.

  12. A Probabilistic Palimpsest Model of Visual Short-term Memory

    Science.gov (United States)

    Matthey, Loic; Bays, Paul M.; Dayan, Peter

    2015-01-01

    Working memory plays a key role in cognition, and yet its mechanisms remain much debated. Human performance on memory tasks is severely limited; however, the two major classes of theory explaining the limits leave open questions about key issues such as how multiple simultaneously-represented items can be distinguished. We propose a palimpsest model, with the occurrent activity of a single population of neurons coding for several multi-featured items. Using a probabilistic approach to storage and recall, we show how this model can account for many qualitative aspects of existing experimental data. In our account, the underlying nature of a memory item depends entirely on the characteristics of the population representation, and we provide analytical and numerical insights into critical issues such as multiplicity and binding. We consider representations in which information about individual feature values is partially separate from the information about binding that creates single items out of multiple features. An appropriate balance between these two types of information is required to capture fully the different types of error seen in human experimental data. Our model provides the first principled account of misbinding errors. We also suggest a specific set of stimuli designed to elucidate the representations that subjects actually employ. PMID:25611204

  13. Director field model of the primary visual cortex for contour detection.

    Directory of Open Access Journals (Sweden)

    Vijay Singh

    Full Text Available We aim to build the simplest possible model capable of detecting long, noisy contours in a cluttered visual scene. For this, we model the neural dynamics in the primate primary visual cortex in terms of a continuous director field that describes the average rate and the average orientational preference of active neurons at a particular point in the cortex. We then use a linear-nonlinear dynamical model with long range connectivity patterns to enforce long-range statistical context present in the analyzed images. The resulting model has substantially fewer degrees of freedom than traditional models, and yet it can distinguish large contiguous objects from the background clutter by suppressing the clutter and by filling-in occluded elements of object contours. This results in high-precision, high-recall detection of large objects in cluttered scenes. Parenthetically, our model has a direct correspondence with the Landau-de Gennes theory of nematic liquid crystal in two dimensions.

  14. Kameleon-live: An analysis and visualization platform for CCMC-hosted models

    Science.gov (United States)

    Pembroke, A. D.; Colbert, J.; De Zeeuw, D.; Wiegand, C.; Boblitt, J. M.; Mullinix, R.

    2016-12-01

    The Community Coordinated Modeling Center is host to a variety of space-weather models, providing low-level access to model output via the Kameleon software suite. We introduce Kameleon-live, a cloud service that provides exploratory tools for CCMC-hosted models, including spatio-temporal interpolation, analysis, and 3D visualization. By lowering the barrier to entry, we hope to enable rapid exploration of space weather model results without needing to download and convert model output, install required packages, or write code. As a collaborative tool, Kameleon-live provides a means for users to privately share their visualizations, as well as document and build a story around their findings. Kameleon-live is also designed to be SPASE-compliant from the ground-up, enabling interoperability and search capability for other space weather data providers.

  15. Task-Difficulty Homeostasis in Car Following Models: Experimental Validation Using Self-Paced Visual Occlusion.

    Science.gov (United States)

    Pekkanen, Jami; Lappi, Otto; Itkonen, Teemu H; Summala, Heikki

    2017-01-01

    Car following (CF) models used in traffic engineering are often criticized for not incorporating "human factors" well known to affect driving. Some recent work has addressed this by augmenting the CF models with the Task-Capability Interface (TCI) model, by dynamically changing driving parameters as function of driver capability. We examined assumptions of these models experimentally using a self-paced visual occlusion paradigm in a simulated car following task. The results show strong, approximately one-to-one, correspondence between occlusion duration and increase in time headway. The correspondence was found between subjects and within subjects, on aggregate and individual sample level. The long time scale aggregate results support TCI-CF models that assume a linear increase in time headway in response to increased distraction. The short time scale individual sample level results suggest that drivers also adapt their visual sampling in response to transient changes in time headway, a mechanism which isn't incorporated in the current models.

  16. Model Pembelajaran VAK (Visualization, Auditory, Kinestethic) untuk Meningkatkan Prestasi Belajar Mata Kuliah Telaah Kurikulum Mahasiswa Pendidikan Biologi 2012

    OpenAIRE

    Mawartiningsih, Lilik

    2016-01-01

    Do research on learning model VAK (Visualization, Auditory, Kinestethic) on Assessing curriculum subjects. This study aims to 1). To determine students' achievement in the subject class of 2012 Assessing curriculum as applied learning model VAK (Visualization , Auditory , Kinestethic), 2). To determine the response or responses of students to study with the model VAK (Visualization, Auditory, Kinestethic). This research was conducted at the University of PGRI Ronggolawe (UNIROW) Tuban on the ...

  17. Conditional Visualization for Statistical Models: An Introduction to the condvis Package in R

    OpenAIRE

    O'Connell, Mark; Hurley, Catherine B.; Domijan, Katarina

    2017-01-01

    The condvis package is for interactive visualization of sections in data space, showing fitted models on the section, and observed data near the section. The primary goal is the interpretation of complex models, and showing how the observed data support the fitted model. There is a video accompaniment to this paper available at https: //www.youtube.com/watch?v=rKFq7xwgdX0.

  18. Constructing and Visualizing Chemical Reaction Networks from Pi-Calculus Models

    OpenAIRE

    John, Mathias; Schulz, Hans-Jörg; Schumann, Heidrun; Uhrmacher, Adelinde; Unger, Andrea

    2012-01-01

    International audience; The pi-calculus, in particular its stochastic version the stochastic pi-calculus, is a common modeling formalism to concisely describe the chemical reactions occurring in biochemical systems. However, it remains largely unexplored how to transform a biochemical model expressed in the stochastic pi-calculus back into a set of meaningful reactions. To this end, we present a two step approach of first translating model states to reaction sets and then visualizing sequence...

  19. A Visual Analysis Concept for the Validation of Geoscientific Simulation Models.

    Science.gov (United States)

    Unger, A; Schulte, S; Klemann, V; Dransch, D

    2012-12-01

    Geoscientific modeling and simulation helps to improve our understanding of the complex Earth system. During the modeling process, validation of the geoscientific model is an essential step. In validation, it is determined whether the model output shows sufficient agreement with observation data. Measures for this agreement are called goodness of fit. In the geosciences, analyzing the goodness of fit is challenging due to its manifold dependencies: 1) The goodness of fit depends on the model parameterization, whose precise values are not known. 2) The goodness of fit varies in space and time due to the spatio-temporal dimension of geoscientific models. 3) The significance of the goodness of fit is affected by resolution and preciseness of available observational data. 4) The correlation between goodness of fit and underlying modeled and observed values is ambiguous. In this paper, we introduce a visual analysis concept that targets these challenges in the validation of geoscientific models - specifically focusing on applications where observation data is sparse, unevenly distributed in space and time, and imprecise, which hinders a rigorous analytical approach. Our concept, developed in close cooperation with Earth system modelers, addresses the four challenges by four tailored visualization components. The tight linking of these components supports a twofold interactive drill-down in model parameter space and in the set of data samples, which facilitates the exploration of the numerous dependencies of the goodness of fit. We exemplify our visualization concept for geoscientific modeling of glacial isostatic adjustments in the last 100,000 years, validated against sea levels indicators - a prominent example for sparse and imprecise observation data. An initial use case and feedback from Earth system modelers indicate that our visualization concept is a valuable complement to the range of validation methods.

  20. Hidden Markov Model Based Visual Perception Filtering in Robotic Soccer

    Directory of Open Access Journals (Sweden)

    Can Kavaklioglu

    2009-02-01

    Full Text Available Autonomous robots can initiate their mission plans only after gathering sufficient information about the environment. Therefore reliable perception information plays a major role in the overall success of an autonomous robot. The Hidden Markov Model based post-perception filtering module proposed in this paper aims to identify and remove spurious perception information in a given perception sequence using the generic metapose definition. This method allows representing uncertainty in more abstract terms compared to the common physical representations. Our experiments with the four legged AIBO robot indicated that the proposed module improved perception and localization performance significantly.

  1. Hidden Markov Model Based Visual Perception Filtering in Robotic Soccer

    Directory of Open Access Journals (Sweden)

    Can Kavaklioglu

    2009-12-01

    Full Text Available Autonomous robots can initiate their mission plans only after gathering sufficient information about the environment. Therefore reliable perception information plays a major role in the overall success of an autonomous robot. The Hidden Markov Model based post-perception filtering module proposed in this paper aims to identify and remove spurious perception information in a given perception sequence using the generic meta-pose definition. This method allows representing uncertainty in more abstract terms compared to the common physical representations. Our experiments with the four legged AIBO robot indicated that the proposed module improved perception and localization performance significantly.

  2. Using a visual discrimination model for the detection of compression artifacts in virtual pathology images.

    Science.gov (United States)

    Johnson, Jeffrey P; Krupinski, Elizabeth A; Yan, Michelle; Roehrig, Hans; Graham, Anna R; Weinstein, Ronald S

    2011-02-01

    A major issue in telepathology is the extremely large and growing size of digitized "virtual" slides, which can require several gigabytes of storage and cause significant delays in data transmission for remote image interpretation and interactive visualization by pathologists. Compression can reduce this massive amount of virtual slide data, but reversible (lossless) methods limit data reduction to less than 50%, while lossy compression can degrade image quality and diagnostic accuracy. "Visually lossless" compression offers the potential for using higher compression levels without noticeable artifacts, but requires a rate-control strategy that adapts to image content and loss visibility. We investigated the utility of a visual discrimination model (VDM) and other distortion metrics for predicting JPEG 2000 bit rates corresponding to visually lossless compression of virtual slides for breast biopsy specimens. Threshold bit rates were determined experimentally with human observers for a variety of tissue regions cropped from virtual slides. For test images compressed to their visually lossless thresholds, just-noticeable difference (JND) metrics computed by the VDM were nearly constant at the 95th percentile level or higher, and were significantly less variable than peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) metrics. Our results suggest that VDM metrics could be used to guide the compression of virtual slides to achieve visually lossless compression while providing 5-12 times the data reduction of reversible methods.

  3. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience

    Science.gov (United States)

    Pelowski, Matthew; Markey, Patrick S.; Lauring, Jon O.; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art. PMID:27199697

  4. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience.

    Science.gov (United States)

    Pelowski, Matthew; Markey, Patrick S; Lauring, Jon O; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art.

  5. Area summation in human visual system: psychophysics, fMRI, and modeling.

    Science.gov (United States)

    Nurminen, Lauri; Kilpeläinen, Markku; Laurinen, Pentti; Vanni, Simo

    2009-11-01

    Contextual modulation is a fundamental feature of sensory processing, both on perceptual and on single-neuron level. When the diameter of a visual stimulus is increased, the firing rate of a cell typically first increases (summation field) and then decreases (surround field). Such an area summation function draws a comprehensive profile of the receptive field structure of a neuron, including areas outside the classical receptive field. We investigated area summation in human vision with psychophysics and functional magnetic resonance imaging (fMRI). The stimuli were drifting sine wave gratings similar to those used in previous macaque single-cell area summation studies [corrected]. A model was developed to facilitate comparison of area summation in fMRI to area summation in psychophysics and single cells. The model consisted of units with an antagonistic receptive field structure found in single cells in the primary visual cortex. The receptive field centers of the model neurons were distributed in the region of the visual field covered by a single voxel. The measured area summation functions were qualitatively similar to earlier single-cell data. The model with parameters derived from psychophysics captured the spatial structure of the summation field in the primary visual cortex as measured with fMRI. The model also generalized to a novel situation in which the neural population was displaced from the stimulus center. The current study shows that contextual modulation arises from similar spatially antagonistic and overlapping excitatory and inhibitory mechanisms, both in single cells and in human vision.

  6. An amodal shared resource model of language-mediated visual attention

    Directory of Open Access Journals (Sweden)

    Alastair Charles Smith

    2013-08-01

    Full Text Available Language-mediated visual attention describes the interaction of two fundamental components of the human cognitive system, language and vision. Within this paper we present an amodal shared resource model of language-mediated visual attention that offers a description of the information and processes involved in this complex multimodal behaviour and a potential explanation for how this ability is acquired. We demonstrate that the model is not only sufficient to account for the experimental effects of Visual World Paradigm studies but also that these effects are emergent properties of the architecture of the model itself, rather than requiring separate information processing channels or modular processing systems. The model provides an explicit description of the connection between the modality-specific input from language and vision and the distribution of eye gaze in language mediated visual attention. The paper concludes by discussing future applications for the model, specifically its potential for investigating the factors driving observed individual differences in language mediated eye gaze.

  7. A New Repeating Color Watermarking Scheme Based on Human Visual Model

    Directory of Open Access Journals (Sweden)

    Chang Chin-Chen

    2004-01-01

    Full Text Available This paper proposes a human-visual-model-based scheme that effectively protects the intellectual copyright of digital images. In the proposed method, the theory of the visual secret sharing scheme is used to create a master watermark share and a secret watermark share. The watermark share is kept secret by the owner. The master watermark share is embedded into the host image to generate a watermarked image based on the human visual model. The proposed method conforms to all necessary conditions of an image watermarking technique. After the watermarked image is put under various attacks such as lossy compression, rotating, sharpening, blurring, and cropping, the experimental results show that the extracted digital watermark from the attacked watermarked images can still be robustly detected using the proposed method.

  8. Bio-physically plausible visualization of highly scattering fluorescent neocortical models for in silico experimentation

    KAUST Repository

    Abdellah, Marwan

    2017-02-15

    Background We present a visualization pipeline capable of accurate rendering of highly scattering fluorescent neocortical neuronal models. The pipeline is mainly developed to serve the computational neurobiology community. It allows the scientists to visualize the results of their virtual experiments that are performed in computer simulations, or in silico. The impact of the presented pipeline opens novel avenues for assisting the neuroscientists to build biologically accurate models of the brain. These models result from computer simulations of physical experiments that use fluorescence imaging to understand the structural and functional aspects of the brain. Due to the limited capabilities of the current visualization workflows to handle fluorescent volumetric datasets, we propose a physically-based optical model that can accurately simulate light interaction with fluorescent-tagged scattering media based on the basic principles of geometric optics and Monte Carlo path tracing. We also develop an automated and efficient framework for generating dense fluorescent tissue blocks from a neocortical column model that is composed of approximately 31000 neurons. Results Our pipeline is used to visualize a virtual fluorescent tissue block of 50 μm3 that is reconstructed from the somatosensory cortex of juvenile rat. The fluorescence optical model is qualitatively analyzed and validated against experimental emission spectra of different fluorescent dyes from the Alexa Fluor family. Conclusion We discussed a scientific visualization pipeline for creating images of synthetic neocortical neuronal models that are tagged virtually with fluorescent labels on a physically-plausible basis. The pipeline is applied to analyze and validate simulation data generated from neuroscientific in silico experiments.

  9. NCWin — A Component Object Model (COM) for processing and visualizing NetCDF data

    Science.gov (United States)

    Liu, Jinxun; Chen, J.M.; Price, D.T.; Liu, S.

    2005-01-01

    NetCDF (Network Common Data Form) is a data sharing protocol and library that is commonly used in large-scale atmospheric and environmental data archiving and modeling. The NetCDF tool described here, named NCWin and coded with Borland C + + Builder, was built as a standard executable as well as a COM (component object model) for the Microsoft Windows environment. COM is a powerful technology that enhances the reuse of applications (as components). Environmental model developers from different modeling environments, such as Python, JAVA, VISUAL FORTRAN, VISUAL BASIC, VISUAL C + +, and DELPHI, can reuse NCWin in their models to read, write and visualize NetCDF data. Some Windows applications, such as ArcGIS and Microsoft PowerPoint, can also call NCWin within the application. NCWin has three major components: 1) The data conversion part is designed to convert binary raw data to and from NetCDF data. It can process six data types (unsigned char, signed char, short, int, float, double) and three spatial data formats (BIP, BIL, BSQ); 2) The visualization part is designed for displaying grid map series (playing forward or backward) with simple map legend, and displaying temporal trend curves for data on individual map pixels; and 3) The modeling interface is designed for environmental model development by which a set of integrated NetCDF functions is provided for processing NetCDF data. To demonstrate that the NCWin can easily extend the functions of some current GIS software and the Office applications, examples of calling NCWin within ArcGIS and MS PowerPoint for showing NetCDF map animations are given.

  10. Bio-physically plausible visualization of highly scattering fluorescent neocortical models for in silico experimentation.

    Science.gov (United States)

    Abdellah, Marwan; Bilgili, Ahmet; Eilemann, Stefan; Shillcock, Julian; Markram, Henry; Schürmann, Felix

    2017-02-15

    We present a visualization pipeline capable of accurate rendering of highly scattering fluorescent neocortical neuronal models. The pipeline is mainly developed to serve the computational neurobiology community. It allows the scientists to visualize the results of their virtual experiments that are performed in computer simulations, or in silico. The impact of the presented pipeline opens novel avenues for assisting the neuroscientists to build biologically accurate models of the brain. These models result from computer simulations of physical experiments that use fluorescence imaging to understand the structural and functional aspects of the brain. Due to the limited capabilities of the current visualization workflows to handle fluorescent volumetric datasets, we propose a physically-based optical model that can accurately simulate light interaction with fluorescent-tagged scattering media based on the basic principles of geometric optics and Monte Carlo path tracing. We also develop an automated and efficient framework for generating dense fluorescent tissue blocks from a neocortical column model that is composed of approximately 31000 neurons. Our pipeline is used to visualize a virtual fluorescent tissue block of 50 μm3 that is reconstructed from the somatosensory cortex of juvenile rat. The fluorescence optical model is qualitatively analyzed and validated against experimental emission spectra of different fluorescent dyes from the Alexa Fluor family. We discussed a scientific visualization pipeline for creating images of synthetic neocortical neuronal models that are tagged virtually with fluorescent labels on a physically-plausible basis. The pipeline is applied to analyze and validate simulation data generated from neuroscientific in silico experiments.

  11. Layer-dependent attentional processing by top-down signals in a visual cortical microcircuit model

    Directory of Open Access Journals (Sweden)

    Nobuhiko eWagatsuma

    2011-07-01

    Full Text Available A vast amount of information about the external world continuously flows into the brain, whereas its capacity to process such information is limited. Attention enables the brain to allocate its resources of information processing to selected sensory inputs for reducing its computational load, and effects of attention have been extensively studied in visual information processing. However, how the microcircuit of the visual cortex processes attentional information from higher areas remains largely unknown. Here, we explore the complex interactions between visual inputs and an attentional signal in a computational model of the visual cortical microcircuit. Our model not only successfully accounts for previous experimental observations of attentional effects on visual neuronal responses, but also predicts contrasting differences in the attentional effects of top-down signals between cortical layers: attention to a preferred stimulus of a column enhances neuronal responses of layers 2/3 and 5, the output stations of cortical microcircuits, whereas attention suppresses neuronal responses of layer 4, the input station of cortical microcircuits. We demonstrate that the specific modulation pattern of layer-4 activity, which emerges from inter-laminar synaptic connections, is crucial for a rapid shift of attention to a currently unattended stimulus. Our results suggest that top-down signals act differently on different layers of the cortical microcircuit.

  12. The effect of non-linear human visual system components on linear model observers

    Science.gov (United States)

    Zhang, Yani; Pham, Binh T.; Eckstein, Miguel P.

    2004-05-01

    Linear model observers have been used successfully to predict human performance in clinically relevant visual tasks for a variety of backgrounds. On the other hand, there has been another family of models used to predict human visual detection of signals superimposed on one of two identical backgrounds (masks). These masking models usually include a number of non-linear components in the channels that reflect properties of the firing of cells in the primary visual cortex (V1). The relationship between these two traditions of models has not been extensively investigated in the context of detection in noise. In this paper, we evaluated the effect of including some of these non-linear components into a linear channelized Hotelling observer (CHO), and the associated practical implications for medical image quality evaluation. In particular, we evaluate whether the rank order evaluation of two compression algorithms (JPEG vs. JPEG 2000) is changed by inclusion of the non-linear components. The results show: a) First that the simpler linear CHO model observer outperforms CHO model with the nonlinear components investigated. b) The rank order of model observer performance for the compression algorithms did not vary when the non-linear components were included. For the present task, the results suggest that the addition of the physiologically based channel non-linearities to a channelized Hotelling might add complexity to the model observers without great impact on medical image quality evaluation.

  13. Visual Prompts or Volunteer Models: An Experiment in Recycling

    Directory of Open Access Journals (Sweden)

    Zi Yin Lin

    2016-05-01

    Full Text Available Successful long-term programs for urban residential food waste sorting are very rare, despite the established urgent need for them in cities for waste reduction, pollution reduction and circular resource economy reasons. This study meets recent calls to bridge policy makers and academics, and calls for more thorough analysis of operational work in terms of behavioral determinants, to move the fields on. It takes a key operational element of a recently reported successful food waste sorting program—manning of the new bins by volunteers—and considers the behavioral determinants involved in order to design a more scalable and cheaper alternative—the use of brightly colored covers with flower designs on three sides of the bin. The two interventions were tested in a medium-scale, real-life experimental set-up that showed that they had statistically similar results: high effective capture rates of 32%–34%, with low contamination rates. The success, low cost and simple implementation of the latter suggests it should be considered for large-scale use. Candidate behavioral determinants are prompts, emotion and knowledge for the yellow bin intervention, and for the volunteer intervention they are additionally social influence, modeling, role clarification, and moderators of messenger type and interpersonal or tailored messaging.

  14. An Integrated Web-Based 3d Modeling and Visualization Platform to Support Sustainable Cities

    Science.gov (United States)

    Amirebrahimi, S.; Rajabifard, A.

    2012-07-01

    Sustainable Development is found as the key solution to preserve the sustainability of cities in oppose to ongoing population growth and its negative impacts. This is complex and requires a holistic and multidisciplinary decision making. Variety of stakeholders with different backgrounds also needs to be considered and involved. Numerous web-based modeling and visualization tools have been designed and developed to support this process. There have been some success stories; however, majority failed to bring a comprehensive platform to support different aspects of sustainable development. In this work, in the context of SDI and Land Administration, CSDILA Platform - a 3D visualization and modeling platform -was proposed which can be used to model and visualize different dimensions to facilitate the achievement of sustainability, in particular, in urban context. The methodology involved the design of a generic framework for development of an analytical and visualization tool over the web. CSDILA Platform was then implemented via number of technologies based on the guidelines provided by the framework. The platform has a modular structure and uses Service-Oriented Architecture (SOA). It is capable of managing spatial objects in a 4D data store and can flexibly incorporate a variety of developed models using the platform's API. Development scenarios can be modeled and tested using the analysis and modeling component in the platform and the results are visualized in seamless 3D environment. The platform was further tested using number of scenarios and showed promising results and potentials to serve a wider need. In this paper, the design process of the generic framework, the implementation of CSDILA Platform and technologies used, and also findings and future research directions will be presented and discussed.

  15. Model-based analysis of patterned motion processing in mouse primary visual cortex

    Directory of Open Access Journals (Sweden)

    Dylan Richard Muir

    2015-08-01

    Full Text Available Neurons in sensory areas of neocortex show responses tuned to specific features of the environment. In visual cortex, information about features such as edges or textures with particular orientations must be integrated to recognize a visual scene or object. Connectivity studies in rodent cortex have revealed that neurons make specific connections within sub-networks sharing common input tuning. In principle, this sub-network architecture enables local cortical circuits to integrate sensory information. However, whether feature integration indeed occurs locally in rodent primary sensory areas has not been examined directly. We studied local integration of sensory features in primary visual cortex (V1 of the mouse by presenting drifting grating and plaid stimuli, while recording the activity of neuronal populations with two-photon calcium imaging. Using a Bayesian model-based analysis framework, we classified single-cell responses as being selective for either individual grating components or for moving plaid patterns. Rather than relying on trial-averaged responses, our model-based framework takes into account single-trial responses and can easily be extended to consider any number of arbitrary predictive models. Our analysis method was able to successfully classify significantly more responses than traditional partial correlation analysis, and provides a rigorous statistical framework to rank any number of models and reject poorly performing models. We also found large a proportion of cells that respond strongly to only one stimulus class. In addition, a quarter of selectively responding neurons had more complex responses that could not be explained by any simple integration model. Our results show that a broad range of pattern integration processes takes place already at the level of primary visual cortex. This diversity of integration is consistent with processing of visual inputs by local sub-networks within V1 that are tuned to combinations

  16. Video Modeling: A Visually Based Intervention for Children with Autism Spectrum Disorder

    Science.gov (United States)

    Ganz, Jennifer B.; Earles-Vollrath, Theresa L.; Cook, Katherine E.

    2011-01-01

    Visually based interventions such as video modeling have been demonstrated to be effective with students with autism spectrum disorder (ASD). This approach has wide utility, is appropriate for use with students of a range of ages and abilities, promotes independent functioning, and can be used to address numerous learner objectives, including…

  17. Helping Students Revise Disruptive Experientially Supported Ideas about Thermodynamics: Computer Visualizations and Tactile Models

    Science.gov (United States)

    Clark, Douglas; Jorde, Doris

    2004-01-01

    This study analyzes the impact of an integrated sensory model within a thermal equilibrium visualization. We hypothesized that this intervention would not only help students revise their disruptive experientially supported ideas about why objects feel hot or cold, but also increase their understanding of thermal equilibrium. The analysis…

  18. Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics

    NARCIS (Netherlands)

    Boulet, J.; Balasubramaniam, R.; Daffertshofer, A.; Longtin, A.

    2010-01-01

    We report on experiments and modelling involving the 'visuo-postural control loop' in the upright stance. We experimentally manipulated an artificial delay to the visual feedback during standing, presented at delays ranging from 0 to 1 s in increments of 250 ms. Using stochastic delay differential

  19. The Effect of Modeling and Visualization Resources on Student Understanding of Physical Hydrology

    Science.gov (United States)

    Marshall, Jilll A.; Castillo, Adam J.; Cardenas, M. Bayani

    2015-01-01

    We investigated the effect of modeling and visualization resources on upper-division, undergraduate and graduate students' performance on an open-ended assessment of their understanding of physical hydrology. The students were enrolled in one of five sections of a physical hydrology course. In two of the sections, students completed homework…

  20. Visualization of simulated small vessels on computed tomography using a model-based iterative reconstruction technique.

    Science.gov (United States)

    Higaki, Toru; Tatsugami, Fuminari; Fujioka, Chikako; Sakane, Hiroaki; Nakamura, Yuko; Baba, Yasutaka; Iida, Makoto; Awai, Kazuo

    2017-08-01

    This article describes a quantitative evaluation of visualizing small vessels using several image reconstruction methods in computed tomography. Simulated vessels with diameters of 1-6 mm made by 3D printer was scanned using 320-row detector computed tomography (CT). Hybrid iterative reconstruction (hybrid IR) and model-based iterative reconstruction (MBIR) were performed for the image reconstruction.

  1. Visualization of simulated small vessels on computed tomography using a model-based iterative reconstruction technique

    OpenAIRE

    Toru Higaki; Fuminari Tatsugami; Chikako Fujioka; Hiroaki Sakane; Yuko Nakamura; Yasutaka Baba; Makoto Iida; Kazuo Awai

    2017-01-01

    This article describes a quantitative evaluation of visualizing small vessels using several image reconstruction methods in computed tomography. Simulated vessels with diameters of 1?6?mm made by 3D printer was scanned using 320-row detector computed tomography (CT). Hybrid iterative reconstruction (hybrid IR) and model-based iterative reconstruction (MBIR) were performed for the image reconstruction.

  2. Making Digital Elevation ModelsAccessible, Comprehensible, and Engaging through Real-Time Visualization

    DEFF Research Database (Denmark)

    Kjeldsen, Thomas Kim; Mikkelsen, Peter Trier; Mosegaard, Jesper

    2015-01-01

    In this paper we present our initial experiments with the new high quality digital elevation model, “Danmarks Højdemodel-2015” (DHM) exposed as an interactive 3D visualization on web and in virtual reality. We argue that such data has great opportunities to spawn new business and new insight...

  3. Selecting the optimal healthcare centers with a modified P-median model: a visual analytic perspective.

    Science.gov (United States)

    Jia, Tao; Tao, Hongbing; Qin, Kun; Wang, Yulong; Liu, Chengkun; Gao, Qili

    2014-10-22

    In a conventional P-median model, demanding points are likely assigned to the closest supplying facilities, but this method exhibits evident limitations in real cases. This paper proposed a modified P-median model in which exact and approximate strategies are used. The first strategy aims to enumerate all of the possible combinations of P facilities, and the second strategy adopts simulated annealing to allocate resources considering capacity constraint and spatial compactness constraint. These strategies allow us to choose optimal locations by applying visual analytics, which is rarely employed in location allocation planning. This model is applied to a case study in Henan Province, China, where three optimal healthcare centers are selected from candidate cities. First, the weighting factor in spatial compactness constraint is visually evaluated to obtain a plausible spatial pattern. Second, three optimal healthcare centers, namely, Zhengzhou, Xinxiang, and Nanyang, are identified in a hybrid transportation network by performing visual analytics. Third, alternative healthcare centers are obtained in a road network and compared with the above solution to understand the impacts of transportation network types. The optimal healthcare centers are visually detected by employing an improved P-median model, which considers both geographic accessibility and service quality. The optimal solutions are obtained in two transportation networks, which suggest high-speed railways and highways play a significant role respectively.

  4. A Comparative Analysis of Spatial Visualization Ability and Drafting Models for Industrial and Technology Education Students

    Science.gov (United States)

    Katsioloudis, Petros; Jovanovic, Vukica; Jones, Mildred

    2014-01-01

    The main purpose of this study was to determine significant positive effects among the use of three different types of drafting models, and to identify whether any differences exist towards promotion of spatial visualization ability for students in Industrial Technology and Technology Education courses. In particular, the study compared the use of…

  5. Visualization of simulated small vessels on computed tomography using a model-based iterative reconstruction technique

    Directory of Open Access Journals (Sweden)

    Toru Higaki

    2017-08-01

    Full Text Available This article describes a quantitative evaluation of visualizing small vessels using several image reconstruction methods in computed tomography. Simulated vessels with diameters of 1–6 mm made by 3D printer was scanned using 320-row detector computed tomography (CT. Hybrid iterative reconstruction (hybrid IR and model-based iterative reconstruction (MBIR were performed for the image reconstruction.

  6. Development of an Estimation Model for Instantaneous Presence in Audio-Visual Content

    National Research Council Canada - National Science Library

    OZAWA, Kenji; TSUKAHARA, Shota; KINOSHITA, Yuichiro; MORISE, Masanori

    2016-01-01

    ...: system presence and content presence. In this study we focused on content presence. To estimate the overall presence of a content item, we have developed estimation models for the sense of presence in audio-only and audio-visual content...

  7. A Probabilistic Model of Visual Working Memory: Incorporating Higher Order Regularities into Working Memory Capacity Estimates

    Science.gov (United States)

    Brady, Timothy F.; Tenenbaum, Joshua B.

    2013-01-01

    When remembering a real-world scene, people encode both detailed information about specific objects and higher order information like the overall gist of the scene. However, formal models of change detection, like those used to estimate visual working memory capacity, assume observers encode only a simple memory representation that includes no…

  8. Models Provide Specificity: Testing a Proposed Mechanism of Visual Working Memory Capacity Development

    Science.gov (United States)

    Simmering, Vanessa R.; Patterson, Rebecca

    2012-01-01

    Numerous studies have established that visual working memory has a limited capacity that increases during childhood. However, debate continues over the source of capacity limits and its developmental increase. Simmering (2008) adapted a computational model of spatial cognitive development, the Dynamic Field Theory, to explain not only the source…

  9. Artist-Teachers' In-Action Mental Models While Teaching Visual Arts

    Science.gov (United States)

    Russo-Zimet, Gila

    2017-01-01

    Studies have examined the assumption that teachers have previous perceptions, beliefs and knowledge about learning (Cochran-Smith & Villegas, 2015). This study presented the In-Action Mental Model of twenty leading artist-teachers while teaching Visual Arts in three Israeli art institutions of higher Education. Data was collected in two…

  10. VisTrails SAHM: visualization and workflow management for species habitat modeling

    Science.gov (United States)

    Morisette, Jeffrey T.; Jarnevich, Catherine S.; Holcombe, Tracy R.; Talbert, Colin B.; Ignizio, Drew; Talbert, Marian; Silva, Claudio; Koop, David; Swanson, Alan; Young, Nicholas E.

    2013-01-01

    The Software for Assisted Habitat Modeling (SAHM) has been created to both expedite habitat modeling and help maintain a record of the various input data, pre- and post-processing steps and modeling options incorporated in the construction of a species distribution model through the established workflow management and visualization VisTrails software. This paper provides an overview of the VisTrails:SAHM software including a link to the open source code, a table detailing the current SAHM modules, and a simple example modeling an invasive weed species in Rocky Mountain National Park, USA.

  11. Cell words: modelling the visual appearance of cells in histopathology images.

    Science.gov (United States)

    Sirinukunwattana, Korsuk; Khan, Adnan M; Rajpoot, Nasir M

    2015-06-01

    Detection and classification of cells in histological images is a challenging task because of the large intra-class variation in the visual appearance of various types of biological cells. In this paper, we propose a discriminative dictionary learning paradigm, termed as Cell Words, for modelling the visual appearance of cells which includes colour, shape, texture and context in a unified manner. The proposed framework is capable of distinguishing mitotic cells from non-mitotic cells (apoptotic, necrotic, epithelial) in breast histology images with high accuracy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. A two-stage neural spiking model of visual contrast detection in perimetry

    Science.gov (United States)

    SK, Gardiner; WH, Swanson; S, Demirel; AM, McKendrick; A, Turpin; CA, Johnson

    2008-01-01

    Perimetry is a commonly used clinical test for visual function, limited by high variability. The sources of this variability need to be better understood. In this paper, we investigate whether noise intrinsic to neural firing could explain the variability in normal subjects. We present the most physiologically accurate model to date for stimulus detection in perimetry combining knowledge of the physiology of components of the visual system with signal detection theory, and show that it requires that detection be mediated by multiple cortical cells in order to give predictions consistent with psychometric functions measured in human observers. PMID:18602414

  13. Self-Organizing Hidden Markov Model Map (SOHMMM): Biological Sequence Clustering and Cluster Visualization.

    Science.gov (United States)

    Ferles, Christos; Beaufort, William-Scott; Ferle, Vanessa

    2017-01-01

    The present study devises mapping methodologies and projection techniques that visualize and demonstrate biological sequence data clustering results. The Sequence Data Density Display (SDDD) and Sequence Likelihood Projection (SLP) visualizations represent the input symbolical sequences in a lower-dimensional space in such a way that the clusters and relations of data elements are depicted graphically. Both operate in combination/synergy with the Self-Organizing Hidden Markov Model Map (SOHMMM). The resulting unified framework is in position to analyze automatically and directly raw sequence data. This analysis is carried out with little, or even complete absence of, prior information/domain knowledge.

  14. Collaborative Visualization for Large-Scale Accelerator Electromagnetic Modeling (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    William J. Schroeder

    2011-11-13

    This report contains the comprehensive summary of the work performed on the SBIR Phase II, Collaborative Visualization for Large-Scale Accelerator Electromagnetic Modeling at Kitware Inc. in collaboration with Stanford Linear Accelerator Center (SLAC). The goal of the work was to develop collaborative visualization tools for large-scale data as illustrated in the figure below. The solutions we proposed address the typical problems faced by geographicallyand organizationally-separated research and engineering teams, who produce large data (either through simulation or experimental measurement) and wish to work together to analyze and understand their data. Because the data is large, we expect that it cannot be easily transported to each team member's work site, and that the visualization server must reside near the data. Further, we also expect that each work site has heterogeneous resources: some with large computing clients, tiled (or large) displays and high bandwidth; others sites as simple as a team member on a laptop computer. Our solution is based on the open-source, widely used ParaView large-data visualization application. We extended this tool to support multiple collaborative clients who may locally visualize data, and then periodically rejoin and synchronize with the group to discuss their findings. Options for managing session control, adding annotation, and defining the visualization pipeline, among others, were incorporated. We also developed and deployed a Web visualization framework based on ParaView that enables the Web browser to act as a participating client in a collaborative session. The ParaView Web Visualization framework leverages various Web technologies including WebGL, JavaScript, Java and Flash to enable interactive 3D visualization over the web using ParaView as the visualization server. We steered the development of this technology by teaming with the SLAC National Accelerator Laboratory. SLAC has a computationally

  15. How patients experience progressive loss of visual function: a model of adjustment using qualitative methods.

    Science.gov (United States)

    Hayeems, R Z; Geller, G; Finkelstein, D; Faden, R R

    2005-05-01

    People with retinitis pigmentosa (RP) experience functional and psychological challenges as they adjust to progressive loss of visual function. The authors aimed to understand better the process of adjusting to RP in light of the emotional suffering associated with this process. Adults with RP were recruited from the Foundation Fighting Blindness and the Wilmer Eye Institute in Baltimore. Focus groups and semistructured interviews addressed the process of adjusting to RP and were audiotaped and transcribed. The transcripts were analysed qualitatively in order to generate a model of adjustment. A total of 43 individuals participated. It was found that, on diagnosis, people with RP seek to understand its meaning in their lives. Mastering the progressive functional implications associated with RP is contingent upon shifting personal identity from a sighted to a visually impaired person. In this sample, six participants self identified as sighted, 10 self identified as in transition, and 27 self identified as visually impaired. This adjustment process can be understood in terms of a five stage model of behaviour change. The proposed model presents one way to understand the process of adjusting to RP and could assist ophthalmologists in meeting their moral obligation to lessen patients' suffering, which arises in the course of their adjustment to progressive loss of visual function.

  16. Aesthetic Perception of Visual Textures: A Holistic Exploration using Texture Analysis, Psychological Experiment and Perception Modeling

    Directory of Open Access Journals (Sweden)

    Jianli eLiu

    2015-11-01

    Full Text Available Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and nonlinear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  17. Aesthetic perception of visual textures: a holistic exploration using texture analysis, psychological experiment, and perception modeling.

    Science.gov (United States)

    Liu, Jianli; Lughofer, Edwin; Zeng, Xianyi

    2015-01-01

    Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design, and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective, and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and non-linear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  18. How spatial abilities and dynamic visualizations interplay when learning functional anatomy with 3D anatomical models.

    Science.gov (United States)

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material presentation formats, spatial abilities, and anatomical tasks. First, to understand the cognitive challenges a novice learner would be faced with when first exposed to 3D anatomical content, a six-step cognitive task analysis was developed. Following this, an experimental study was conducted to explore how presentation formats (dynamic vs. static visualizations) support learning of functional anatomy, and affect subsequent anatomical tasks derived from the cognitive task analysis. A second aim was to investigate the interplay between spatial abilities (spatial visualization and spatial relation) and presentation formats when the functional anatomy of a 3D scapula and the associated shoulder flexion movement are learned. Findings showed no main effect of the presentation formats on performances, but revealed the predictive influence of spatial visualization and spatial relation abilities on performance. However, an interesting interaction between presentation formats and spatial relation ability for a specific anatomical task was found. This result highlighted the influence of presentation formats when spatial abilities are involved as well as the differentiated influence of spatial abilities on anatomical tasks. © 2015 American Association of Anatomists.

  19. A GIS-Enabled, Michigan-Specific, Hierarchical Groundwater Modeling and Visualization System

    Science.gov (United States)

    Liu, Q.; Li, S.; Mandle, R.; Simard, A.; Fisher, B.; Brown, E.; Ross, S.

    2005-12-01

    Efficient management of groundwater resources relies on a comprehensive database that represents the characteristics of the natural groundwater system as well as analysis and modeling tools to describe the impacts of decision alternatives. Many agencies in Michigan have spent several years compiling expensive and comprehensive surface water and groundwater inventories and other related spatial data that describe their respective areas of responsibility. However, most often this wealth of descriptive data has only been utilized for basic mapping purposes. The benefits from analyzing these data, using GIS analysis functions or externally developed analysis models or programs, has yet to be systematically realized. In this talk, we present a comprehensive software environment that allows Michigan groundwater resources managers and frontline professionals to make more effective use of the available data and improve their ability to manage and protect groundwater resources, address potential conflicts, design cleanup schemes, and prioritize investigation activities. In particular, we take advantage of the Interactive Ground Water (IGW) modeling system and convert it to a customized software environment specifically for analyzing, modeling, and visualizing the Michigan statewide groundwater database. The resulting Michigan IGW modeling system (IGW-M) is completely window-based, fully interactive, and seamlessly integrated with a GIS mapping engine. The system operates in real-time (on the fly) providing dynamic, hierarchical mapping, modeling, spatial analysis, and visualization. Specifically, IGW-M allows water resources and environmental professionals in Michigan to: * Access and utilize the extensive data from the statewide groundwater database, interactively manipulate GIS objects, and display and query the associated data and attributes; * Analyze and model the statewide groundwater database, interactively convert GIS objects into numerical model features

  20. Model-Based Synthesis of Visual Speech Movements from 3D Video

    Directory of Open Access Journals (Sweden)

    Edge JamesD

    2009-01-01

    Full Text Available We describe a method for the synthesis of visual speech movements using a hybrid unit selection/model-based approach. Speech lip movements are captured using a 3D stereo face capture system and split up into phonetic units. A dynamic parameterisation of this data is constructed which maintains the relationship between lip shapes and velocities; within this parameterisation a model of how lips move is built and is used in the animation of visual speech movements from speech audio input. The mapping from audio parameters to lip movements is disambiguated by selecting only the most similar stored phonetic units to the target utterance during synthesis. By combining properties of model-based synthesis (e.g., HMMs, neural nets with unit selection we improve the quality of our speech synthesis.

  1. A Hyperbolic Ontology Visualization Tool for Model Application Programming Interface Documentation

    Science.gov (United States)

    Hyman, Cody

    2011-01-01

    Spacecraft modeling, a critically important portion in validating planned spacecraft activities, is currently carried out using a time consuming method of mission to mission model implementations and integration. A current project in early development, Integrated Spacecraft Analysis (ISCA), aims to remedy this hindrance by providing reusable architectures and reducing time spent integrating models with planning and sequencing tools. The principle objective of this internship was to develop a user interface for an experimental ontology-based structure visualization of navigation and attitude control system modeling software. To satisfy this, a number of tree and graph visualization tools were researched and a Java based hyperbolic graph viewer was selected for experimental adaptation. Early results show promise in the ability to organize and display large amounts of spacecraft model documentation efficiently and effectively through a web browser. This viewer serves as a conceptual implementation for future development but trials with both ISCA developers and end users should be performed to truly evaluate the effectiveness of continued development of such visualizations.

  2. Development of internal models and predictive abilities for visual tracking during childhood.

    Science.gov (United States)

    Ego, Caroline; Yüksel, Demet; Orban de Xivry, Jean-Jacques; Lefèvre, Philippe

    2016-01-01

    The prediction of the consequences of our own actions through internal models is an essential component of motor control. Previous studies showed improvement of anticipatory behaviors with age for grasping, drawing, and postural control. Since these actions require visual and proprioceptive feedback, these improvements might reflect both the development of internal models and the feedback control. In contrast, visual tracking of a temporarily invisible target gives specific markers of prediction and internal models for eye movements. Therefore, we recorded eye movements in 50 children (aged 5-19 yr) and in 10 adults, who were asked to pursue a visual target that is temporarily blanked. Results show that the youngest children (5-7 yr) have a general oculomotor behavior in this task, qualitatively similar to the one observed in adults. However, the overall performance of older subjects in terms of accuracy at target reappearance and variability in their behavior was much better than the youngest children. This late maturation of predictive mechanisms with age was reflected into the development of the accuracy of the internal models governing the synergy between the saccadic and pursuit systems with age. Altogether, we hypothesize that the maturation of the interaction between smooth pursuit and saccades that relies on internal models of the eye and target displacement is related to the continuous maturation of the cerebellum. Copyright © 2016 the American Physiological Society.

  3. Implementation of ICARE learning model using visualization animation on biotechnology course

    Science.gov (United States)

    Hidayat, Habibi

    2017-12-01

    ICARE is a learning model that directly ensure the students to actively participate in the learning process using animation media visualization. ICARE have five key elements of learning experience from children and adult that is introduction, connection, application, reflection and extension. The use of Icare system to ensure that participants have opportunity to apply what have been they learned. So that, the message delivered by lecture to students can be understood and recorded by students in a long time. Learning model that was deemed capable of improving learning outcomes and interest to learn in following learning process Biotechnology with applying the ICARE learning model using visualization animation. This learning model have been giving motivation to participate in the learning process and learning outcomes obtained becomes more increased than before. From the results of student learning in subjects Biotechnology by applying the ICARE learning model using Visualization Animation can improving study results of student from the average value of middle test amounted to 70.98 with the percentage of 75% increased value of final test to be 71.57 with the percentage of 68.63%. The interest to learn from students more increasing visits of student activities at each cycle, namely the first cycle obtained average value by 33.5 with enough category. The second cycle is obtained an average value of 36.5 to good category and third cycle the average value of 36.5 with a student activity to good category.

  4. 3-dimensional orthodontics visualization system with dental study models and orthopantomograms

    Science.gov (United States)

    Zhang, Hua; Ong, S. H.; Foong, K. W. C.; Dhar, T.

    2005-04-01

    The aim of this study is to develop a system that provides 3-dimensional visualization of orthodontic treatments. Dental plaster models and corresponding orthopantomogram (dental panoramic tomogram) are first digitized and fed into the system. A semi-auto segmentation technique is applied to the plaster models to detect the dental arches, tooth interstices and gum margins, which are used to extract individual crown models. 3-dimensional representation of roots, generated by deforming generic tooth models with orthopantomogram using radial basis functions, is attached to corresponding crowns to enable visualization of complete teeth. An optional algorithm to close the gaps between deformed roots and actual crowns by using multi-quadratic radial basis functions is also presented, which is capable of generating smooth mesh representation of complete 3-dimensional teeth. User interface is carefully designed to achieve a flexible system with as much user friendliness as possible. Manual calibration and correction is possible throughout the data processing steps to compensate occasional misbehaviors of automatic procedures. By allowing the users to move and re-arrange individual teeth (with their roots) on a full dentition, this orthodontic visualization system provides an easy and accurate way of simulation and planning of orthodontic treatment. Its capability of presenting 3-dimensional root information with only study models and orthopantomogram is especially useful for patients who do not undergo CT scanning, which is not a routine procedure in most orthodontic cases.

  5. Development of the Object-Oriented Dynamic Simulation Models Using Visual C++ Freeware

    Directory of Open Access Journals (Sweden)

    Alexander I. Kozynchenko

    2016-01-01

    Full Text Available The paper mostly focuses on the methodological and programming aspects of developing a versatile desktop framework to provide the available basis for the high-performance simulation of dynamical models of different kinds and for diverse applications. So the paper gives some basic structure for creating a dynamical simulation model in C++ which is built on the Win32 platform with an interactive multiwindow interface and uses the lightweight Visual C++ Express as a free integrated development environment. The resultant simulation framework could be a more acceptable alternative to other solutions developed on the basis of commercial tools like Borland C++ or Visual C++ Professional, not to mention the domain specific languages and more specialized ready-made software such as Matlab, Simulink, and Modelica. This approach seems to be justified in the case of complex research object-oriented dynamical models having nonstandard structure, relationships, algorithms, and solvers, as it allows developing solutions of high flexibility. The essence of the model framework is shown using a case study of simulation of moving charged particles in the electrostatic field. The simulation model possesses the necessary visualization and control features such as an interactive input, real time graphical and text output, start, stop, and rate control.

  6. The performance & flow visualization studies of three-dimensional (3-D) wind turbine blade models

    Science.gov (United States)

    Sutrisno, Prajitno, Purnomo, W., Setyawan B.

    2016-06-01

    Recently, studies on the design of 3-D wind turbine blades have a less attention even though 3-D blade products are widely sold. In contrary, advanced studies in 3-D helicopter blade tip have been studied rigorously. Studies in wind turbine blade modeling are mostly assumed that blade spanwise sections behave as independent two-dimensional airfoils, implying that there is no exchange of momentum in the spanwise direction. Moreover, flow visualization experiments are infrequently conducted. Therefore, a modeling study of wind turbine blade with visualization experiment is needed to be improved to obtain a better understanding. The purpose of this study is to investigate the performance of 3-D wind turbine blade models with backward-forward swept and verify the flow patterns using flow visualization. In this research, the blade models are constructed based on the twist and chord distributions following Schmitz's formula. Forward and backward swept are added to the rotating blades. Based on this, the additional swept would enhance or diminish outward flow disturbance or stall development propagation on the spanwise blade surfaces to give better blade design. Some combinations, i. e., b lades with backward swept, provide a better 3-D favorable rotational force of the rotor system. The performance of the 3-D wind turbine system model is measured by a torque meter, employing Prony's braking system. Furthermore, the 3-D flow patterns around the rotating blade models are investigated by applying "tuft-visualization technique", to study the appearance of laminar, separated, and boundary layer flow patterns surrounding the 3-dimentional blade system.

  7. Visually guided tube thoracostomy insertion comparison to standard of care in a large animal model.

    Science.gov (United States)

    Hernandez, Matthew C; Vogelsang, David; Anderson, Jeff R; Thiels, Cornelius A; Beilman, Gregory; Zielinski, Martin D; Aho, Johnathon M

    2017-04-01

    Tube thoracostomy (TT) is a lifesaving procedure for a variety of thoracic pathologies. The most commonly utilized method for placement involves open dissection and blind insertion. Image guided placement is commonly utilized but is limited by an inability to see distal placement location. Unfortunately, TT is not without complications. We aim to demonstrate the feasibility of a disposable device to allow for visually directed TT placement compared to the standard of care in a large animal model. Three swine were sequentially orotracheally intubated and anesthetized. TT was conducted utilizing a novel visualization device, tube thoracostomy visual trocar (TTVT) and standard of care (open technique). Position of the TT in the chest cavity were recorded using direct thoracoscopic inspection and radiographic imaging with the operator blinded to results. Complications were evaluated using a validated complication grading system. Standard descriptive statistical analyses were performed. Thirty TT were placed, 15 using TTVT technique, 15 using standard of care open technique. All of the TT placed using TTVT were without complication and in optimal position. Conversely, 27% of TT placed using standard of care open technique resulted in complications. Necropsy revealed no injury to intrathoracic organs. Visual directed TT placement using TTVT is feasible and non-inferior to the standard of care in a large animal model. This improvement in instrumentation has the potential to greatly improve the safety of TT. Further study in humans is required. Therapeutic Level II. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Objects Classification by Learning-Based Visual Saliency Model and Convolutional Neural Network

    Directory of Open Access Journals (Sweden)

    Na Li

    2016-01-01

    Full Text Available Humans can easily classify different kinds of objects whereas it is quite difficult for computers. As a hot and difficult problem, objects classification has been receiving extensive interests with broad prospects. Inspired by neuroscience, deep learning concept is proposed. Convolutional neural network (CNN as one of the methods of deep learning can be used to solve classification problem. But most of deep learning methods, including CNN, all ignore the human visual information processing mechanism when a person is classifying objects. Therefore, in this paper, inspiring the completed processing that humans classify different kinds of objects, we bring forth a new classification method which combines visual attention model and CNN. Firstly, we use the visual attention model to simulate the processing of human visual selection mechanism. Secondly, we use CNN to simulate the processing of how humans select features and extract the local features of those selected areas. Finally, not only does our classification method depend on those local features, but also it adds the human semantic features to classify objects. Our classification method has apparently advantages in biology. Experimental results demonstrated that our method made the efficiency of classification improve significantly.

  9. A web-application for visualizing uncertainty in numerical ensemble models

    Science.gov (United States)

    Alberti, Koko; Hiemstra, Paul; de Jong, Kor; Karssenberg, Derek

    2013-04-01

    Numerical ensemble models are used in the analysis and forecasting of a wide range of environmental processes. Common use cases include assessing the consequences of nuclear accidents, pollution releases into the ocean or atmosphere, forest fires, volcanic eruptions, or identifying areas at risk from such hazards. In addition to the increased use of scenario analyses and model forecasts, the availability of supplementary data describing errors and model uncertainties is increasingly commonplace. Unfortunately most current visualization routines are not capable of properly representing uncertain information. As a result, uncertainty information is not provided at all, not readily accessible, or it is not communicated effectively to model users such as domain experts, decision makers, policy makers, or even novice users. In an attempt to address these issues a lightweight and interactive web-application has been developed. It makes clear and concise uncertainty visualizations available in a web-based mapping and visualization environment, incorporating aggregation (upscaling) techniques to adjust uncertainty information to the zooming level. The application has been built on a web mapping stack of open source software, and can quantify and visualize uncertainties in numerical ensemble models in such a way that both expert and novice users can investigate uncertainties present in a simple ensemble dataset. As a test case, a dataset was used which forecasts the spread of an airborne tracer across Western Europe. Extrinsic uncertainty representations are used in which dynamic circular glyphs are overlaid on model attribute maps to convey various uncertainty concepts. It supports both basic uncertainty metrics such as standard deviation, standard error, width of the 95% confidence interval and interquartile range, as well as more experimental ones aimed at novice users. Ranges of attribute values can be specified, and the circular glyphs dynamically change size to

  10. Flow visualization and modeling for education and outreach in low-income countries

    Science.gov (United States)

    Motanated, K.

    2016-12-01

    Being able to visualize the dynamic interaction between the movement of water and sediment flux is undeniably a profound tool for students and novices to understand complicated earth surface processes. In a laser-sheet flow visualization technique, a light source that is thin and monochromatic is required to illuminate sediments or tracers in the flow. However, an ideal laser sheet generator is rather expensive, especially for schools and universities residing in low-income countries. This project is proposing less-expensive options for a laser-sheet source and flow visualization experiment configuration for qualitative observation and quantitative analysis of the interaction between fluid media and sediments. Here, Fresnel lens is used to convert from point laser into sheet laser. Multiple combinations of laser diodes of various wavelength (nanometer) and power (milliwatt) and Fresnel lenses of various dimensions are analyzed. The pair that is able to produce the thinnest and brightest light sheet is not only effective but also affordable. The motion of sediments in a flow can be observed by illuminating the laser-sheet in an interested flow region. The particle motion is recorded by a video camera that is capable of taking multiple frames per second and having a narrow depth of view. The recorded video file can be played in a slow-motion mode so students can visually observe and qualitatively analyze the particle motion. An open source software package for Particle Imaging Velocimetry (PIV) can calculate the local velocity of particles from still images extracted from the video and create a vector map depicting particle motion. This flow visualization experiment is inexpensive and the configuration is simple to setup. Most importantly, this flow visualization technique serves as a fundamental tool for earth surface process education and can further be applied to sedimentary process modeling.

  11. Visual deficits in a mouse model of Fetal alcohol spectrum disorders

    Directory of Open Access Journals (Sweden)

    Crystal L Lantz

    2014-10-01

    Full Text Available Alcohol consumption during pregnancy can lead to a multitude of neurological problems in offspring, varying from subtle behavioral changes to severe mental retardation. These alterations are collectively referred to as Fetal Alcohol Spectrum Disorders (FASD. Early alcohol exposure can strongly affect the visual system and children with FASD can exhibit an amblyopia-like pattern of visual acuity deficits even in the absence of optical and oculormotor disruption.Here we test whether early alcohol exposure can lead to a disruption in visual acuity, using a model of FASD to mimic alcohol consumption in the last months of human gestation. To accomplish this, mice were exposed to ethanol (5g/kg i.p or saline on postnatal days (P 5, 7 and 9. Two to three weeks later we recorded visually evoked potentials (VEPs to assess spatial frequency detection and contrast sensitivity, conducted electroretinography (ERGs to further assess visual function and imaged retinotopy using optical imaging of intrinsic signals. We observed that animals exposed to ethanol displayed spatial frequency acuity curves similar to controls. However, ethanol-treated animals showed a significant deficit in contrast sensitivity. Moreover, ERGs revealed a market decrease in both a- and b- waves amplitudes, and optical imaging suggest that both elevation and azimuth maps in ethanol-treated animals have a 10-20o greater map tilt compared to saline-treated controls. Overall, our findings suggest that binge alcohol drinking restricted to the last months of gestation in humans can lead to marked deficits in visual function.

  12. 3D MODELLING AND VISUALIZATION BASED ON THE UNITY GAME ENGINE – ADVANTAGES AND CHALLENGES

    Directory of Open Access Journals (Sweden)

    I. Buyuksalih

    2017-11-01

    Full Text Available 3D City modelling is increasingly popular and becoming valuable tools in managing big cities. Urban and energy planning, landscape, noise-sewage modelling, underground mapping and navigation are among the applications/fields which really depend on 3D modelling for their effectiveness operations. Several research areas and implementation projects had been carried out to provide the most reliable 3D data format for sharing and functionalities as well as visualization platform and analysis. For instance, BIMTAS company has recently completed a project to estimate potential solar energy on 3D buildings for the whole Istanbul and now focussing on 3D utility underground mapping for a pilot case study. The research and implementation standard on 3D City Model domain (3D data sharing and visualization schema is based on CityGML schema version 2.0. However, there are some limitations and issues in implementation phase for large dataset. Most of the limitations were due to the visualization, database integration and analysis platform (Unity3D game engine as highlighted in this paper.

  13. D Modelling and Visualization Based on the Unity Game Engine - Advantages and Challenges

    Science.gov (United States)

    Buyuksalih, I.; Bayburt, S.; Buyuksalih, G.; Baskaraca, A. P.; Karim, H.; Rahman, A. A.

    2017-11-01

    3D City modelling is increasingly popular and becoming valuable tools in managing big cities. Urban and energy planning, landscape, noise-sewage modelling, underground mapping and navigation are among the applications/fields which really depend on 3D modelling for their effectiveness operations. Several research areas and implementation projects had been carried out to provide the most reliable 3D data format for sharing and functionalities as well as visualization platform and analysis. For instance, BIMTAS company has recently completed a project to estimate potential solar energy on 3D buildings for the whole Istanbul and now focussing on 3D utility underground mapping for a pilot case study. The research and implementation standard on 3D City Model domain (3D data sharing and visualization schema) is based on CityGML schema version 2.0. However, there are some limitations and issues in implementation phase for large dataset. Most of the limitations were due to the visualization, database integration and analysis platform (Unity3D game engine) as highlighted in this paper.

  14. Visual imagery and the user model applied to fuel handling at EBR-II

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A.

    1995-06-01

    The material presented in this paper is based on two studies involving visual display designs and the user`s perspective model of a system. The studies involved a methodology known as Neuro-Linguistic Programming (NLP), and its use in expanding design choices which included the ``comfort parameters`` and ``perspective reality`` of the user`s model of the world. In developing visual displays for the EBR-II fuel handling system, the focus would be to incorporate the comfort parameters that overlap from each of the representation systems: visual, auditory and kinesthetic then incorporate the comfort parameters of the most prominent group of the population, and last, blend in the other two representational system comfort parameters. The focus of this informal study was to use the techniques of meta-modeling and synesthesia to develop a virtual environment that closely resembled the operator`s perspective of the fuel handling system of Argonne`s Experimental Breeder Reactor - II. An informal study was conducted using NLP as the behavioral model in a v reality (VR) setting.

  15. D Modelling and Interactive Web-Based Visualization of Cultural Heritage Objects

    Science.gov (United States)

    Koeva, M. N.

    2016-06-01

    Nowadays, there are rapid developments in the fields of photogrammetry, laser scanning, computer vision and robotics, together aiming to provide highly accurate 3D data that is useful for various applications. In recent years, various LiDAR and image-based techniques have been investigated for 3D modelling because of their opportunities for fast and accurate model generation. For cultural heritage preservation and the representation of objects that are important for tourism and their interactive visualization, 3D models are highly effective and intuitive for present-day users who have stringent requirements and high expectations. Depending on the complexity of the objects for the specific case, various technological methods can be applied. The selected objects in this particular research are located in Bulgaria - a country with thousands of years of history and cultural heritage dating back to ancient civilizations. This motivates the preservation, visualisation and recreation of undoubtedly valuable historical and architectural objects and places, which has always been a serious challenge for specialists in the field of cultural heritage. In the present research, comparative analyses regarding principles and technological processes needed for 3D modelling and visualization are presented. The recent problems, efforts and developments in interactive representation of precious objects and places in Bulgaria are presented. Three technologies based on real projects are described: (1) image-based modelling using a non-metric hand-held camera; (2) 3D visualization based on spherical panoramic images; (3) and 3D geometric and photorealistic modelling based on architectural CAD drawings. Their suitability for web-based visualization are demonstrated and compared. Moreover the possibilities for integration with additional information such as interactive maps, satellite imagery, sound, video and specific information for the objects are described. This comparative study

  16. 3D MODELLING AND INTERACTIVE WEB-BASED VISUALIZATION OF CULTURAL HERITAGE OBJECTS

    Directory of Open Access Journals (Sweden)

    M. N. Koeva

    2016-06-01

    Full Text Available Nowadays, there are rapid developments in the fields of photogrammetry, laser scanning, computer vision and robotics, together aiming to provide highly accurate 3D data that is useful for various applications. In recent years, various LiDAR and image-based techniques have been investigated for 3D modelling because of their opportunities for fast and accurate model generation. For cultural heritage preservation and the representation of objects that are important for tourism and their interactive visualization, 3D models are highly effective and intuitive for present-day users who have stringent requirements and high expectations. Depending on the complexity of the objects for the specific case, various technological methods can be applied. The selected objects in this particular research are located in Bulgaria – a country with thousands of years of history and cultural heritage dating back to ancient civilizations. \\this motivates the preservation, visualisation and recreation of undoubtedly valuable historical and architectural objects and places, which has always been a serious challenge for specialists in the field of cultural heritage. In the present research, comparative analyses regarding principles and technological processes needed for 3D modelling and visualization are presented. The recent problems, efforts and developments in interactive representation of precious objects and places in Bulgaria are presented. Three technologies based on real projects are described: (1 image-based modelling using a non-metric hand-held camera; (2 3D visualization based on spherical panoramic images; (3 and 3D geometric and photorealistic modelling based on architectural CAD drawings. Their suitability for web-based visualization are demonstrated and compared. Moreover the possibilities for integration with additional information such as interactive maps, satellite imagery, sound, video and specific information for the objects are described. This

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

    DEFF Research Database (Denmark)

    Bruun, Hans Peter Lomholt; Mortensen, Niels Henrik

    2012-01-01

    The goal of this paper is to determine the role of a product architecture model to support communication and to form the basis for developing and maintaining information of product structures in a PLM system. This paper contains descriptions of a modelling tool to represent a product architecture...... in a company to support the development of a family of products, as well as the reasons leading to the use of the specific model and its terminology. The fundamental idea for using the architecture model is that an improved understanding of the whole product system, will lead to better decision making....... Moreover, it is discussed how the sometimes intangible elements and phenomena within an architecture model can be visually modeled in order to form the basis for a data model in a PLM system. © 2012 International Federation for Information Processing....

  18. Visualization and modeling of impurity atom migration for superdiffusion in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Wada, T. [Nagoya Sangyo University, Aichi (Japan); Kojiguchi, K. [Nagoya Sangyo University, Aichi (Japan); Nagao, H. [Graduate School of information Science, Nagoya University (Japan); Fujimoto, H. [Daido institute of Technology, Nagoya (Japan)]. E-mail: fujimoto@daido-it.ac.jp

    2006-04-01

    Radiation-enhanced superdiffusion in two-layered structures, comprised of an impurity overlayer and a semiconductor substrate, subjected to electron beam irradiation is modeled and visualized using computer graphics animation. The important and experimentally observed large sticking probabilities of impurities at the wafer surface were modeled in the algorithm, and the animation was found to behave as expected under irradiation. Programming of the animation algorithm was performed using an object modeling technique. The animation generated a continuous display of radiation-enhanced superdiffusion that was qualitatively consistent with experimental observations, thereby facilitating understanding of the superdiffusion process.

  19. ACTIVIS: Visual Exploration of Industry-Scale Deep Neural Network Models.

    Science.gov (United States)

    Kahng, Minsuk; Andrews, Pierre Y; Kalro, Aditya; Polo Chau, Duen Horng

    2017-08-30

    While deep learning models have achieved state-of-the-art accuracies for many prediction tasks, understanding these models remains a challenge. Despite the recent interest in developing visual tools to help users interpret deep learning models, the complexity and wide variety of models deployed in industry, and the large-scale datasets that they used, pose unique design challenges that are inadequately addressed by existing work. Through participatory design sessions with over 15 researchers and engineers at Facebook, we have developed, deployed, and iteratively improved ACTIVIS, an interactive visualization system for interpreting large-scale deep learning models and results. By tightly integrating multiple coordinated views, such as a computation graph overview of the model architecture, and a neuron activation view for pattern discovery and comparison, users can explore complex deep neural network models at both the instance- and subset-level. ACTIVIS has been deployed on Facebook's machine learning platform. We present case studies with Facebook researchers and engineers, and usage scenarios of how ACTIVIS may work with different models.

  20. From Agents to Continuous Change via Aesthetics: Learning Mechanics with Visual Agentbased Computational Modeling

    CERN Document Server

    Sengupta, Pratim; Wright, Mason

    2013-01-01

    Novice learners find motion as a continuous process of change challenging to understand. In this paper, we present a pedagogical approach based on agent-based, visual programming to address this issue. Integrating Logo programming with curricular science has been shown to be challenging in previous research on educational computing. We present a new Logo-based visual programming language - ViMAP - and, a sequence of learning activities involving programming and modeling, designed specifically to support seamless integration between programming and learning kinematics. We describe relevant affordances of the ViMAP environment that supports such seamless integration. We then present ViMAP-MoMo, a curricular unit designed in ViMAP for modeling kinematics, for a wide range of students (elementary - high school). The main contribution of this paper is that we describe in detail a sequence of learning activities in three phases, discuss the underlying rationale for each phase, and where relevant, report results in ...

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

    Science.gov (United States)

    Matuzevicius, Dalius; Vaitkevicius, Henrikas

    2014-03-01

    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.

  2. Phonological and visual distinctiveness effects in syllogistic reasoning: implications for mental models theory.

    Science.gov (United States)

    Ball, Linden J; Quayle, Jeremy D

    2009-09-01

    Two experiments are reported in which the representational distinctiveness of terms within categorical syllogisms was manipulated in order to examine the assumption of mental models theory that abstract, spatially based representations underpin deduction. In Experiment 1, participants evaluated conclusion validity for syllogisms containing either phonologically distinctive terms (e.g., harks, paps, and fids) or phonologically nondistinctive terms (e.g., fuds, fods, and feds). Logical performance was enhanced with the distinctive contents, suggesting that the phonological properties of syllogism terms can play an important role in deduction. In Experiment 2, participants received either the phonological materials from Experiment 1 or syllogisms involving distinctive or nondistinctive visual contents. Logical inference was again enhanced for the distinctive contents, whether phonological or visual in nature. Our findings suggest a broad involvement of multimodal information in syllogistic reasoning and question the assumed primacy of abstract, spatially organized representations in deduction, as is claimed by mental models theorists.

  3. Stereoscopic 3D Visual Discomfort Prediction: A Dynamic Accommodation and Vergence Interaction Model.

    Science.gov (United States)

    Oh, Heeseok; Lee, Sanghoon; Bovik, Alan Conrad

    2016-02-01

    The human visual system perceives 3D depth following sensing via its binocular optical system, a series of massively parallel processing units, and a feedback system that controls the mechanical dynamics of eye movements and the crystalline lens. The process of accommodation (focusing of the crystalline lens) and binocular vergence is controlled simultaneously and symbiotically via cross-coupled communication between the two critical depth computation modalities. The output responses of these two subsystems, which are induced by oculomotor control, are used in the computation of a clear and stable cyclopean 3D image from the input stimuli. These subsystems operate in smooth synchronicity when one is viewing the natural world; however, conflicting responses can occur when viewing stereoscopic 3D (S3D) content on fixed displays, causing physiological discomfort. If such occurrences could be predicted, then they might also be avoided (by modifying the acquisition process) or ameliorated (by changing the relative scene depth). Toward this end, we have developed a dynamic accommodation and vergence interaction (DAVI) model that successfully predicts visual discomfort on S3D images. The DAVI model is based on the phasic and reflex responses of the fast fusional vergence mechanism. Quantitative models of accommodation and vergence mismatches are used to conduct visual discomfort prediction. Other 3D perceptual elements are included in the proposed method, including sharpness limits imposed by the depth of focus and fusion limits implied by Panum's fusional area. The DAVI predictor is created by training a support vector machine on features derived from the proposed model and on recorded subjective assessment results. The experimental results are shown to produce accurate predictions of experienced visual discomfort.

  4. A Simple Model-Based Approach to Inferring and Visualizing Cancer Mutation Signatures.

    Directory of Open Access Journals (Sweden)

    Yuichi Shiraishi

    2015-12-01

    Full Text Available Recent advances in sequencing technologies have enabled the production of massive amounts of data on somatic mutations from cancer genomes. These data have led to the detection of characteristic patterns of somatic mutations or "mutation signatures" at an unprecedented resolution, with the potential for new insights into the causes and mechanisms of tumorigenesis. Here we present new methods for modelling, identifying and visualizing such mutation signatures. Our methods greatly simplify mutation signature models compared with existing approaches, reducing the number of parameters by orders of magnitude even while increasing the contextual factors (e.g. the number of flanking bases that are accounted for. This improves both sensitivity and robustness of inferred signatures. We also provide a new intuitive way to visualize the signatures, analogous to the use of sequence logos to visualize transcription factor binding sites. We illustrate our new method on somatic mutation data from urothelial carcinoma of the upper urinary tract, and a larger dataset from 30 diverse cancer types. The results illustrate several important features of our methods, including the ability of our new visualization tool to clearly highlight the key features of each signature, the improved robustness of signature inferences from small sample sizes, and more detailed inference of signature characteristics such as strand biases and sequence context effects at the base two positions 5' to the mutated site. The overall framework of our work is based on probabilistic models that are closely connected with "mixed-membership models" which are widely used in population genetic admixture analysis, and in machine learning for document clustering. We argue that recognizing these relationships should help improve understanding of mutation signature extraction problems, and suggests ways to further improve the statistical methods. Our methods are implemented in an R package

  5. Visual recognition system of cherry picking robot based on Lab color model

    Science.gov (United States)

    Zhang, Qirong; Zuo, Jianjun; Yu, Tingzhong; Wang, Yan

    2017-12-01

    This paper designs a visual recognition system suitable for cherry picking. First, the system deals with the image using the vector median filter. And then it extracts a channel of Lab color model to divide the cherries and the background. The cherry contour was successfully fitted by the least square method, and the centroid and radius of the cherry were extracted. Finally, the cherry was successfully extracted.

  6. Large-scale functional models of visual cortex for remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Brumby, Steven P [Los Alamos National Laboratory; Kenyon, Garrett [Los Alamos National Laboratory; Rasmussen, Craig E [Los Alamos National Laboratory; Swaminarayan, Sriram [Los Alamos National Laboratory; Bettencourt, Luis [Los Alamos National Laboratory; Landecker, Will [PORTLAND STATE UNIV.

    2009-01-01

    Neuroscience has revealed many properties of neurons and of the functional organization of visual cortex that are believed to be essential to human vision, but are missing in standard artificial neural networks. Equally important may be the sheer scale of visual cortex requiring {approx}1 petaflop of computation. In a year, the retina delivers {approx}1 petapixel to the brain, leading to massively large opportunities for learning at many levels of the cortical system. We describe work at Los Alamos National Laboratory (LANL) to develop large-scale functional models of visual cortex on LANL's Roadrunner petaflop supercomputer. An initial run of a simple region VI code achieved 1.144 petaflops during trials at the IBM facility in Poughkeepsie, NY (June 2008). Here, we present criteria for assessing when a set of learned local representations is 'complete' along with general criteria for assessing computer vision models based on their projected scaling behavior. Finally, we extend one class of biologically-inspired learning models to problems of remote sensing imagery.

  7. Visualization of laser tattoo removal treatment effects in a mouse model by two-photon microscopy

    Science.gov (United States)

    Jang, Won Hyuk; Yoon, Yeoreum; Kim, Wonjoong; Kwon, Soonjae; Lee, Seunghun; Song, Duke; Choi, Jong Woon; Kim, Ki Hean

    2017-01-01

    Laser tattoo removal is an effective method of eliminating tattoo particles in the skin. However, laser treatment cannot always remove the unwanted tattoo completely, and there are risks of either temporary or permanent side effects. Studies using preclinical animal models could provide detailed information on the effects of laser treatment in the skin, and might help to minimize side effects in clinical practices. In this study, two-photon microscopy (TPM) was used to visualize the laser treatment effects on tattoo particles in both phantom specimens and in vivo mouse models. Fluorescent tattoo ink was used for particle visualization by TPM, and nanosecond (ns) and picosecond (ps) lasers at 532 nm were used for treatment. In phantom specimens, TPM characterized the fragmentation of individual tattoo particles by tracking them before and after the laser treatment. These changes were confirmed by field emission scanning electron microscopy (FE-SEM). TPM was used to measure the treatment efficiency of the two lasers at different laser fluences. In the mouse model, TPM visualized clusters of tattoo particles in the skin and detected their fragmentation after the laser treatment. Longitudinal TPM imaging observed the migration of cells containing tattoo particles after the laser treatment. These results show that TPM may be useful for the assessment of laser tattoo removal treatment in preclinical studies. PMID:28856046

  8. Visualization of laser tattoo removal treatment effects in a mouse model by two-photon microscopy.

    Science.gov (United States)

    Jang, Won Hyuk; Yoon, Yeoreum; Kim, Wonjoong; Kwon, Soonjae; Lee, Seunghun; Song, Duke; Choi, Jong Woon; Kim, Ki Hean

    2017-08-01

    Laser tattoo removal is an effective method of eliminating tattoo particles in the skin. However, laser treatment cannot always remove the unwanted tattoo completely, and there are risks of either temporary or permanent side effects. Studies using preclinical animal models could provide detailed information on the effects of laser treatment in the skin, and might help to minimize side effects in clinical practices. In this study, two-photon microscopy (TPM) was used to visualize the laser treatment effects on tattoo particles in both phantom specimens and in vivo mouse models. Fluorescent tattoo ink was used for particle visualization by TPM, and nanosecond (ns) and picosecond (ps) lasers at 532 nm were used for treatment. In phantom specimens, TPM characterized the fragmentation of individual tattoo particles by tracking them before and after the laser treatment. These changes were confirmed by field emission scanning electron microscopy (FE-SEM). TPM was used to measure the treatment efficiency of the two lasers at different laser fluences. In the mouse model, TPM visualized clusters of tattoo particles in the skin and detected their fragmentation after the laser treatment. Longitudinal TPM imaging observed the migration of cells containing tattoo particles after the laser treatment. These results show that TPM may be useful for the assessment of laser tattoo removal treatment in preclinical studies.

  9. Intraocular Telescopic System Design: Optical and Visual Simulation in a Human Eye Model.

    Science.gov (United States)

    Zoulinakis, Georgios; Ferrer-Blasco, Teresa

    2017-01-01

    Purpose. To design an intraocular telescopic system (ITS) for magnifying retinal image and to simulate its optical and visual performance after implantation in a human eye model. Methods. Design and simulation were carried out with a ray-tracing and optical design software. Two different ITS were designed, and their visual performance was simulated using the Liou-Brennan eye model. The difference between the ITS was their lenses' placement in the eye model and their powers. Ray tracing in both centered and decentered situations was carried out for both ITS while visual Strehl ratio (VSOTF) was computed using custom-made MATLAB code. Results. The results show that between 0.4 and 0.8 mm of decentration, the VSOTF does not change much either for far or near target distances. The image projection for these decentrations is in the parafoveal zone, and the quality of the image projected is quite similar. Conclusion. Both systems display similar quality while they differ in size; therefore, the choice between them would need to take into account specific parameters from the patient's eye. Quality does not change too much between 0.4 and 0.8 mm of decentration for either system which gives flexibility to the clinician to adjust decentration to avoid areas of retinal damage.

  10. Intraocular Telescopic System Design: Optical and Visual Simulation in a Human Eye Model

    Directory of Open Access Journals (Sweden)

    Georgios Zoulinakis

    2017-01-01

    Full Text Available Purpose. To design an intraocular telescopic system (ITS for magnifying retinal image and to simulate its optical and visual performance after implantation in a human eye model. Methods. Design and simulation were carried out with a ray-tracing and optical design software. Two different ITS were designed, and their visual performance was simulated using the Liou-Brennan eye model. The difference between the ITS was their lenses’ placement in the eye model and their powers. Ray tracing in both centered and decentered situations was carried out for both ITS while visual Strehl ratio (VSOTF was computed using custom-made MATLAB code. Results. The results show that between 0.4 and 0.8 mm of decentration, the VSOTF does not change much either for far or near target distances. The image projection for these decentrations is in the parafoveal zone, and the quality of the image projected is quite similar. Conclusion. Both systems display similar quality while they differ in size; therefore, the choice between them would need to take into account specific parameters from the patient’s eye. Quality does not change too much between 0.4 and 0.8 mm of decentration for either system which gives flexibility to the clinician to adjust decentration to avoid areas of retinal damage.

  11. Different developmental trajectories across feature types support a dynamic field model of visual working memory development.

    Science.gov (United States)

    Simmering, Vanessa R; Miller, Hilary E; Bohache, Kevin

    2015-05-01

    Research on visual working memory has focused on characterizing the nature of capacity limits as "slots" or "resources" based almost exclusively on adults' performance with little consideration for developmental change. Here we argue that understanding how visual working memory develops can shed new light onto the nature of representations. We present an alternative model, the Dynamic Field Theory (DFT), which can capture effects that have been previously attributed either to "slot" or "resource" explanations. The DFT includes a specific developmental mechanism to account for improvements in both resolution and capacity of visual working memory throughout childhood. Here we show how development in the DFT can account for different capacity estimates across feature types (i.e., color and shape). The current paper tests this account by comparing children's (3, 5, and 7 years of age) performance across different feature types. Results showed that capacity for colors increased faster over development than capacity for shapes. A second experiment confirmed this difference across feature types within subjects, but also showed that the difference can be attenuated by testing memory for less familiar colors. Model simulations demonstrate how developmental changes in connectivity within the model-purportedly arising through experience-can capture differences across feature types.

  12. cellPACK: a virtual mesoscope to model and visualize structural systems biology.

    Science.gov (United States)

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

    2015-01-01

    cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10-100 nm) between molecular and cellular biology scales. cellPACK's modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive three-dimensional models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is available as open-source code, with tools for validation of models and with 'recipes' and models for five biological systems: blood plasma, cytoplasm, synaptic vesicles, HIV and a mycoplasma cell. We have applied cellPACK to model distributions of HIV envelope protein to test several hypotheses for consistency with experimental observations. Biologists, educators and outreach specialists can interact with cellPACK models, develop new recipes and perform packing experiments through scripting and graphical user interfaces at http://cellPACK.org/.

  13. Development, implementation and evaluation of an information model for archetype based user responsive medical data visualization.

    Science.gov (United States)

    Kopanitsa, Georgy; Veseli, Hasan; Yampolsky, Vladimir

    2015-06-01

    When medical data have been successfully recorded or exchanged between systems there appear a need to present the data consistently to ensure that it is clearly understood and interpreted. A standard based user interface can provide interoperability on the visual level. The goal of this research was to develop, implement and evaluate an information model for building user interfaces for archetype based medical data. The following types of knowledge were identified as important elements and were included in the information model: medical content related attributes, data type related attributes, user-related attributes, device-related attributes. In order to support flexible and efficient user interfaces an approach that represents different types of knowledge with different models separating the medical concept from a visual concept and interface realization was chosen. We evaluated the developed approach using Guideline for Good Evaluation Practice in Health Informatics (GEP-HI). We developed a higher level information model to complement the ISO 13606 archetype model. This enabled the specification of the presentation properties at the moment of the archetypes' definition. The model allows realizing different users' perspectives on the data. The approach was implemented and evaluated within a functioning EHR system. The evaluation involved 30 patients of different age and IT experience and 5 doctors. One month of testing showed that the time required reading electronic health records decreased for both doctors (from average 310 to 220s) and patients (from average 95 to 39s). Users reported a high level of satisfaction and motivation to use the presented data visualization approach especially in comparison with their previous experience. The introduced information model allows separating medical knowledge and presentation knowledge. The additional presentation layer will enrich the graphical user interface's flexibility and will allow an optimal presentation of

  14. Visual setup of logical models of signaling and regulatory networks with ProMoT

    Directory of Open Access Journals (Sweden)

    Gilles Ernst

    2006-11-01

    Full Text Available Abstract Background The analysis of biochemical networks using a logical (Boolean description is an important approach in Systems Biology. Recently, new methods have been proposed to analyze large signaling and regulatory networks using this formalism. Even though there is a large number of tools to set up models describing biological networks using a biochemical (kinetic formalism, however, they do not support logical models. Results Herein we present a flexible framework for setting up large logical models in a visual manner with the software tool ProMoT. An easily extendible library, ProMoT's inherent modularity and object-oriented concept as well as adaptive visualization techniques provide a versatile environment. Both the graphical and the textual description of the logical model can be exported to different formats. Conclusion New features of ProMoT facilitate an efficient set-up of large Boolean models of biochemical interaction networks. The modeling environment is flexible; it can easily be adapted to specific requirements, and new extensions can be introduced. ProMoT is freely available from http://www.mpi-magdeburg.mpg.de/projects/promot/.

  15. Visual setup of logical models of signaling and regulatory networks with ProMoT.

    Science.gov (United States)

    Saez-Rodriguez, Julio; Mirschel, Sebastian; Hemenway, Rebecca; Klamt, Steffen; Gilles, Ernst Dieter; Ginkel, Martin

    2006-11-17

    The analysis of biochemical networks using a logical (Boolean) description is an important approach in Systems Biology. Recently, new methods have been proposed to analyze large signaling and regulatory networks using this formalism. Even though there is a large number of tools to set up models describing biological networks using a biochemical (kinetic) formalism, however, they do not support logical models. Herein we present a flexible framework for setting up large logical models in a visual manner with the software tool ProMoT. An easily extendible library, ProMoT's inherent modularity and object-oriented concept as well as adaptive visualization techniques provide a versatile environment. Both the graphical and the textual description of the logical model can be exported to different formats. New features of ProMoT facilitate an efficient set-up of large Boolean models of biochemical interaction networks. The modeling environment is flexible; it can easily be adapted to specific requirements, and new extensions can be introduced. ProMoT is freely available from http://www.mpi-magdeburg.mpg.de/projects/promot/.

  16. Biologically Inspired Model for Visual Cognition Achieving Unsupervised Episodic and Semantic Feature Learning.

    Science.gov (United States)

    Qiao, Hong; Li, Yinlin; Li, Fengfu; Xi, Xuanyang; Wu, Wei

    2016-10-01

    Recently, many biologically inspired visual computational models have been proposed. The design of these models follows the related biological mechanisms and structures, and these models provide new solutions for visual recognition tasks. In this paper, based on the recent biological evidence, we propose a framework to mimic the active and dynamic learning and recognition process of the primate visual cortex. From principle point of view, the main contributions are that the framework can achieve unsupervised learning of episodic features (including key components and their spatial relations) and semantic features (semantic descriptions of the key components), which support higher level cognition of an object. From performance point of view, the advantages of the framework are as follows: 1) learning episodic features without supervision-for a class of objects without a prior knowledge, the key components, their spatial relations and cover regions can be learned automatically through a deep neural network (DNN); 2) learning semantic features based on episodic features-within the cover regions of the key components, the semantic geometrical values of these components can be computed based on contour detection; 3) forming the general knowledge of a class of objects-the general knowledge of a class of objects can be formed, mainly including the key components, their spatial relations and average semantic values, which is a concise description of the class; and 4) achieving higher level cognition and dynamic updating-for a test image, the model can achieve classification and subclass semantic descriptions. And the test samples with high confidence are selected to dynamically update the whole model. Experiments are conducted on face images, and a good performance is achieved in each layer of the DNN and the semantic description learning process. Furthermore, the model can be generalized to recognition tasks of other objects with learning ability.

  17. The visualization of DHSI based on the relationship model of CL and SA

    Science.gov (United States)

    Wang, Haibo; Guo, Huijuan; Xue, Chengqi

    2013-03-01

    The source and cause of cognitive load (CL) and situation awareness (SA) in digital human-system interface (DHSI) is explained. Based on the analysis of cognitive procedure and the relation of CL and SA, The relationship model of CL and SA in DHSI is put forward. Using the association target and the relationship model of CL and SA, the method and strategy of information visualization of DHSI is presented which is based on the cognitive psychology. Selecting the Boeing 757 autopilot as the case, the comparison of design is shown.

  18. An experimental model of urethral stricture in rabbits using holmium laser under urethroscopic direct visualization.

    Science.gov (United States)

    Hu, Wei-Feng; Li, Cui-Ling; Zhang, Hui-Ping; Li, Ting-Ting; Zeng, Xiao-Yong

    2014-01-01

    To establish an experimental rabbit model of urethral stricture using holmium laser under direct urethroscopic visualization. Sixteen adult male New Zealand rabbits were divided into equally-sized control and experimental groups. All rabbits underwent retrograde urethrography and transurethral endoscopy with a 7.5 F urethroscope after intramuscular anesthetic injection. We used a holmium:YAG laser to injure the distal urethra in all rabbits in the experimental group under direct visualization. Thirty days after surgery, all animals were evaluated with retrograde urethrography and urethroscopy. The flow rate of the isolated urethras was measured to evaluate urethral stricture formation. One rabbit in the experimental group (12.5%) died of infection 4 days after surgery. Thirty days after surgery, retrograde urethrography and urethroscopy revealed strictures in all seven surviving rabbits (87.5%) in the experimental group. The mean flow rate of the isolated urethras was significantly lower in the experimental group than in the control group. A rabbit model of urethral stricture can be successfully established using holmium laser under direct urethroscopic visualization, providing an ideal object for research concerning the pathogenesis and molecular biology of urethral strictures. © 2014 S. Karger AG, Basel.

  19. Incorporating a Wheeled Vehicle Model in a New Monocular Visual Odometry Algorithm for Dynamic Outdoor Environments

    Science.gov (United States)

    Jiang, Yanhua; Xiong, Guangming; Chen, Huiyan; Lee, Dah-Jye

    2014-01-01

    This paper presents a monocular visual odometry algorithm that incorporates a wheeled vehicle model for ground vehicles. The main innovation of this algorithm is to use the single-track bicycle model to interpret the relationship between the yaw rate and side slip angle, which are the two most important parameters that describe the motion of a wheeled vehicle. Additionally, the pitch angle is also considered since the planar-motion hypothesis often fails due to the dynamic characteristics of wheel suspensions and tires in real-world environments. Linearization is used to calculate a closed-form solution of the motion parameters that works as a hypothesis generator in a RAndom SAmple Consensus (RANSAC) scheme to reduce the complexity in solving equations involving trigonometric. All inliers found are used to refine the winner solution through minimizing the reprojection error. Finally, the algorithm is applied to real-time on-board visual localization applications. Its performance is evaluated by comparing against the state-of-the-art monocular visual odometry methods using both synthetic data and publicly available datasets over several kilometers in dynamic outdoor environments. PMID:25256109

  20. SonifEye: Sonification of Visual Information Using Physical Modeling Sound Synthesis.

    Science.gov (United States)

    Roodaki, Hessam; Navab, Navid; Eslami, Abouzar; Stapleton, Christopher; Navab, Nassir

    2017-11-01

    Sonic interaction as a technique for conveying information has advantages over conventional visual augmented reality methods specially when augmenting the visual field with extra information brings distraction. Sonification of knowledge extracted by applying computational methods to sensory data is a well-established concept. However, some aspects of sonic interaction design such as aesthetics, the cognitive effort required for perceiving information, and avoiding alarm fatigue are not well studied in literature. In this work, we present a sonification scheme based on employment of physical modeling sound synthesis which targets focus demanding tasks requiring extreme precision. Proposed mapping techniques are designed to require minimum training for users to adapt to and minimum mental effort to interpret the conveyed information. Two experiments are conducted to assess the feasibility of the proposed method and compare it against visual augmented reality in high precision tasks. The observed quantitative results suggest that utilizing sound patches generated by physical modeling achieve the desired goal of improving the user experience and general task performance with minimal training.

  1. Integrating a geographic information system, a scientific visualization system, and a precipitation model

    Science.gov (United States)

    Hay, L.E.; Knapp, L.K.

    1996-01-01

    Investigating natural, potential, and human-induced impacts on hydrologic systems commonly requires complex modeling with overlapping data requirements, plus massive amounts of one- to four-dimensional data at multiple scales and formats. Given the complexity of most hydrologic studies, the requisite software infrastructure must incorporate many components including simulation modeling and spatial analysis with a flexible, intuitive display. Integrating geographic information systems (GIS) and scientific visualization systems (SVS) provides such an infrastructure. This paper describes an integrated system consisting of an orographic precipitation model, a GIS, and an SVS. The results of this study provide a basis for improving the understanding of hydro-climatic processes in mountainous regions. An additional benefit of the integrated system, the value of which is often underestimated, is the improved ability to communicate model results, leading to a broader understanding of the model assumptions, sensitivities, and conclusions at a management level.Investigating natural, potential, and human-induced impacts on hydrologic systems commonly requires complex modeling with overlapping data requirements, plus massive amounts of one- to four-dimensional data at multiple scales and formats. Given the complexity of most hydrologic studies, the requisite software infrastructure must incorporate many components including simulation modeling and spatial analysis with a flexible, intuitive display. Integrating geographic information systems (GIS) and scientific visualization systems (SVS) provides such an infrastructure. This paper describes an integrated system consisting of an orographic precipitation model, a GIS, and an SVS. The results of this study provide a basis for improving the understanding of hydro-climatic processes in mountainous regions. An additional benefit of the integrated system, the value of which is often underestimated, is the improved ability to

  2. detecting multiple sclerosis lesions with a fully bioinspired visual attention model

    Science.gov (United States)

    Villalon-Reina, Julio; Gutierrez-Carvajal, Ricardo; Thompson, Paul M.; Romero-Castro, Eduardo

    2013-11-01

    The detection, segmentation and quantification of multiple sclerosis (MS) lesions on magnetic resonance images (MRI) has been a very active field for the last two decades because of the urge to correlate these measures with the effectiveness of pharmacological treatment. A myriad of methods has been developed and most of these are non specific for the type of lesions and segment the lesions in their acute and chronic phases together. On the other hand, radiologists are able to distinguish between several stages of the disease on different types of MRI images. The main motivation of the work presented here is to computationally emulate the visual perception of the radiologist by using modeling principles of the neuronal centers along the visual system. By using this approach we are able to detect the lesions in the majority of the images in our population sample. This type of approach also allows us to study and improve the analysis of brain networks by introducing a priori information.

  3. Encoder: a connectionist model of how learning to visually encode fixated text images improves reading fluency.

    Science.gov (United States)

    Martin, Gale L

    2004-07-01

    This article proposes that visual encoding learning improves reading fluency by widening the span over which letters are recognized from a fixated text image so that fewer fixations are needed to cover a text line. Encoder is a connectionist model that learns to convert images like the fixated text images human readers encode into the corresponding letter sequences. The computational theory of classification learning predicts that fixated text-image size makes this learning difficult but that reducing image variability and biasing learning should help. Encoder confirms these predictions. It fails to learn as image size increases but achieves humanlike visual encoding accuracy when image variability is reduced by regularities in fixation positions and letter sequences and when learning is biased to discover mapping functions based on the sequential, componential structure of text. After training, Encoder exhibits many humanlike text familiarity effects. ((c) 2004 APA, all rights reserved)

  4. Combining universal beauty and cultural context in a unifying model of visual aesthetic experience.

    Science.gov (United States)

    Redies, Christoph

    2015-01-01

    In this work, I propose a model of visual aesthetic experience that combines formalist and contextual aspects of aesthetics. The model distinguishes between two modes of processing. First, perceptual processing is based on the intrinsic form of an artwork, which may or may not be beautiful. If it is beautiful, a beauty-responsive mechanism is activated in the brain. This bottom-up mechanism is universal amongst humans; it is widespread in the visual brain and responsive across visual modalities. Second, cognitive processing is based on contextual information, such as the depicted content, the intentions of the artist or the circumstances of the presentation of the artwork. Cognitive processing is partially top-down and varies between individuals according to their cultural experience. Processing in the two channels is parallel and largely independent. In the general case, an aesthetic experience is induced if processing in both channels is favorable, i.e., if there is resonance in the perceptual processing channel ("aesthetics of perception"), and successful mastering in the cognitive processing channel ("aesthetics of cognition"). I speculate that this combinatorial mechanism has evolved to mediate social bonding between members of a (cultural) group of people. Primary emotions can be elicited via both channels and modulate the degree of the aesthetic experience. Two special cases are discussed. First, in a subset of (post-)modern art, beauty no longer plays a prominent role. Second, in some forms of abstract art, beautiful form can be enjoyed with minimal cognitive processing. The model is applied to examples of Western art. Finally, implications of the model are discussed. In summary, the proposed model resolves the seeming contradiction between formalist perceptual approaches to aesthetic experience, which are based on the intrinsic beauty of artworks, and contextual approaches, which account for highly individual and culturally dependent aspects of aesthetics.

  5. Web Based Interactive Anaglyph Stereo Visualization of 3D Model of Geoscience Data

    Science.gov (United States)

    Han, J.

    2014-12-01

    The objectives of this study were to create interactive online tool for generating and viewing the anaglyph 3D stereo image on a Web browser via Internet. To achieve this, we designed and developed the prototype system. Three-dimensional visualization is well known and becoming popular in recent years to understand the target object and the related physical phenomena. Geoscience data have the complex data model, which combines large extents with rich small scale visual details. So, the real-time visualization of 3D geoscience data model on the Internet is a challenging work. In this paper, we show the result of creating which can be viewed in 3D anaglyph of geoscience data in any web browser which supports WebGL. We developed an anaglyph image viewing prototype system, and some representative results are displayed by anaglyph 3D stereo image generated in red-cyan colour from pairs of air-photo/digital elevation model and geological map/digital elevation model respectively. The best viewing is achieved by using suitable 3D red-cyan glasses, although alternatively red-blue or red-green spectacles can be also used. The middle mouse wheel can be used to zoom in/out the anaglyph image on a Web browser. Application of anaglyph 3D stereo image is a very important and easy way to understand the underground geologic system and active tectonic geomorphology. The integrated strata with fine three-dimensional topography and geologic map data can help to characterise the mineral potential area and the active tectonic abnormal characteristics. To conclude, it can be stated that anaglyph 3D stereo image provides a simple and feasible method to improve the relief effect of geoscience data such as geomorphology and geology. We believe that with further development, the anaglyph 3D stereo imaging system could as a complement to 3D geologic modeling, constitute a useful tool for better understanding of the underground geology and the active tectonic

  6. Combining universal beauty and cultural context in a unifying model of visual aesthetic experience

    Directory of Open Access Journals (Sweden)

    Christoph eRedies

    2015-04-01

    Full Text Available In this work, I propose a model of visual aesthetic experience that combines formalist and contextual aspects of aesthetics. The model distinguishes between two modes of processing. First, perceptual processing is based on the intrinsic form of an artwork, which may or may not be beautiful. If it is beautiful, a beauty-responsive mechanism is activated in the brain. This bottom-up mechanism is universal amongst humans; it is widespread in the visual brain and responsive across visual modalities. Second, cognitive processing is based on contextual information, such as the depicted content, the intentions of the artist or the circumstances of the presentation of the artwork. Cognitive processing is partially top-down and varies between individuals according to their cultural experience. Processing in the two channels is parallel and largely independent. In the general case, an aesthetic experience is induced if processing in both channels is favorable, i.e., if there is resonance in the perceptual processing channel (aesthetics of perception, and successful mastering in the cognitive processing channel (aesthetics of cognition. I speculate that this combinatorial mechanism has evolved to mediate social bonding between members of a (cultural group of people. Primary emotions can be elicited via both channels and modulate the degree of the aesthetic experience. Two special cases are discussed. First, in a subset of (post-modern art, beauty no longer plays a prominent role. Second, in some forms of abstract art, beautiful form can be enjoyed with minimal cognitive processing. The model is applied to examples of Western art. Finally, implications of the model are discussed.In summary, the proposed model resolves the seeming contradiction between formalist perceptual approaches to aesthetic experience, which are based on the intrinsic beauty of artworks, and contextual approaches, which account for highly individual and culturally dependent aspects of

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

    Directory of Open Access Journals (Sweden)

    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

  8. EFEK PENGGUNAAN MODEL PEMBELAJARAN INQUIRY TRAINING BERBANTUAN MEDIA VISUAL DAN KREATIVITAS TERHADAP KETERAMPILAN PROSES SAINS SISWA

    Directory of Open Access Journals (Sweden)

    Derlina Derlina

    2016-06-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui efek penggunaan model pembelajaran inquiry training berbantuan media visual dan kreativitas terhadap keterampilan proses sains siswa SMP. Penelitian dilaksanakan di SMP Amir Hamzah Medan Tahun Pelajaran 2014/2015. Sampel penelitian ditentukan secara cluster sampling, satu kelas sebagai kelas eksperimen dibelajarkan dengan model pembelajaran inquiry training dan satu kelas kontrol dibelajarkan secara konvensional. Uji hipotesis menggunakan ANAVA dua jalur. Instrumen penelitian terdiri dari tes keterampilan proses sains dan tes kreativitas. Hasil penelitian diperoleh bahwa (1 Keterampilan proses sains  siswa yang dibelajarkan dengan model pembelajaran inquiry training menggunakan media visual lebih baik dari yang dibelajarkan secara konvensional. (2 Keterampilan proses sains  siswa yang memiliki  kreativitas tinggi lebih baik dari siswa dengan  kreativitas rendah. (3 Terdapat interaksi antara model pembelajaran inquiry training dan pembelajaran konvensional dengan kreativitas siswa dalam meningkatkan keterampilan proses sains siswa.   Kata kunci : Model pembelajaran inquiry training, kreativitas, keterampilan                       proses sains

  9. 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

  10. Integrating a geographic information system, a scientific visualization system and an orographic precipitation model

    Science.gov (United States)

    Hay, L.; Knapp, L.

    1996-01-01

    Investigating natural, potential, and man-induced impacts on hydrological systems commonly requires complex modelling with overlapping data requirements, and massive amounts of one- to four-dimensional data at multiple scales and formats. Given the complexity of most hydrological studies, the requisite software infrastructure must incorporate many components including simulation modelling, spatial analysis and flexible, intuitive displays. There is a general requirement for a set of capabilities to support scientific analysis which, at this time, can only come from an integration of several software components. Integration of geographic information systems (GISs) and scientific visualization systems (SVSs) is a powerful technique for developing and analysing complex models. This paper describes the integration of an orographic precipitation model, a GIS and a SVS. The combination of these individual components provides a robust infrastructure which allows the scientist to work with the full dimensionality of the data and to examine the data in a more intuitive manner.

  11. 'It's the sight not the bite': a model and reinterpretation of visually-based developmental fears.

    Science.gov (United States)

    Berger, Michael

    2010-08-01

    Early childhood fears are common and transient. Some may give rise to specific phobias persisting into adulthood. The origins and nature of early fears and phobias and their relationship with later phobias remain contentious. This paper examines and aims to resolve some of the associated theoretical and clinical issues using a reinterpretation derived from the neural model introduced here. The foundation of the model is evidence that neonates and infants react to the hedonic (pleasant/unpleasant) properties of visual stimuli, suggesting that such reactivity is inherent in visual systems. A model of the reactivity and the associated learning, based on the work of LeDoux (2000) and others, is used to argue that certain stimuli, such as the sight of snakes, produce intrinsic aversive effects. These become associated with stimulus identity (a snake). External consequences (a bite) are not required for the learning. Such associations can form the basis of developmental and some later fears and phobias. The contributions of the model and its limitations are discussed. It is then applied to reinterpreting 'developmental fears' and specific phobias, proposing that reactivity to certain stimulus properties begins early and remains over the life-span, leading to the potential for phobias to arise at any time, even without earlier precursors, and for treated phobias to re-emerge. Some of the research and clinical and implications of this reinterpretation are highlighted. Copyright 2010 Elsevier B.V. All rights reserved.

  12. A robotics-based approach to modeling of choice reaching experiments on visual attention

    Directory of Open Access Journals (Sweden)

    Soeren eStrauss

    2012-04-01

    Full Text Available The paper presents a robotics-based model for choice reaching experiments on visual attention. In these experiments participants were asked to make rapid reach movements towards a target in an odd-colour search task, i.e. reaching for a green square among red squares and vice versa (e.g. Song & Nakayama, 2008. Interestingly these studies found that in a high number of trials movements were initially directed towards a distractor and only later were adjusted towards the target. These curved trajectories occurred particularly frequently when the target in the directly preceding trial had a different colour (priming effect. Our model is embedded in a closed-loop control of a LEGO robot arm aiming to mimic these reach movements. The model is based on our earlier work which suggests that target selection in visual search is implemented through parallel interactions between competitive and cooperative processes in the brain (Heinke & Backhaus, 2011; Heinke & Humphreys, 2003. To link this model with the control of the robot arm we implemented a topological representation of movement parameters following the dynamic field theory (Erlhagen & Schoener, 2002. The robot arm is able to mimic the results of the odd-colour search task including the priming effect and also generates human-like trajectories with a bell-shaped velocity profile. Theoretical implications and predictions are discussed in the paper.

  13. STUDY ON MODELING AND VISUALIZING THE POSITIONAL UNCERTAINTY OF REMOTE SENSING IMAGE

    Directory of Open Access Journals (Sweden)

    W. Jiao

    2016-06-01

    Full Text Available It is inevitable to bring about uncertainty during the process of data acquisition. The traditional method to evaluate the geometric positioning accuracy is usually by the statistical method and represented by the root mean square errors (RMSEs of control points. It is individual and discontinuous, so it is difficult to describe the error spatial distribution. In this paper the error uncertainty of each control point is deduced, and the uncertainty spatial distribution model of each arbitrary point is established. The error model is proposed to evaluate the geometric accuracy of remote sensing image. Then several visualization methods are studied to represent the discrete and continuous data of geometric uncertainties. The experiments show that the proposed evaluation method of error distribution model compared with the traditional method of RMSEs can get the similar results but without requiring the user to collect control points as checkpoints, and error distribution information calculated by the model can be provided to users along with the geometric image data. Additionally, the visualization methods described in this paper can effectively and objectively represents the image geometric quality, and also can help users probe the reasons of bringing the image uncertainties in some extent.

  14. A Robotics-Based Approach to Modeling of Choice Reaching Experiments on Visual Attention

    Science.gov (United States)

    Strauss, Soeren; Heinke, Dietmar

    2012-01-01

    The paper presents a robotics-based model for choice reaching experiments on visual attention. In these experiments participants were asked to make rapid reach movements toward a target in an odd-color search task, i.e., reaching for a green square among red squares and vice versa (e.g., Song and Nakayama, 2008). Interestingly these studies found that in a high number of trials movements were initially directed toward a distractor and only later were adjusted toward the target. These “curved” trajectories occurred particularly frequently when the target in the directly preceding trial had a different color (priming effect). Our model is embedded in a closed-loop control of a LEGO robot arm aiming to mimic these reach movements. The model is based on our earlier work which suggests that target selection in visual search is implemented through parallel interactions between competitive and cooperative processes in the brain (Heinke and Humphreys, 2003; Heinke and Backhaus, 2011). To link this model with the control of the robot arm we implemented a topological representation of movement parameters following the dynamic field theory (Erlhagen and Schoener, 2002). The robot arm is able to mimic the results of the odd-color search task including the priming effect and also generates human-like trajectories with a bell-shaped velocity profile. Theoretical implications and predictions are discussed in the paper. PMID:22529827

  15. Serial recall of colors: Two models of memory for serial order applied to continuous visual stimuli.

    Science.gov (United States)

    Peteranderl, Sonja; Oberauer, Klaus

    2018-01-01

    This study investigated the effects of serial position and temporal distinctiveness on serial recall of simple visual stimuli. Participants observed lists of five colors presented at varying, unpredictably ordered interitem intervals, and their task was to reproduce the colors in their order of presentation by selecting colors on a continuous-response scale. To control for the possibility of verbal labeling, articulatory suppression was required in one of two experimental sessions. The predictions were derived through simulation from two computational models of serial recall: SIMPLE represents the class of temporal-distinctiveness models, whereas SOB-CS represents event-based models. According to temporal-distinctiveness models, items that are temporally isolated within a list are recalled more accurately than items that are temporally crowded. In contrast, event-based models assume that the time intervals between items do not affect recall performance per se, although free time following an item can improve memory for that item because of extended time for the encoding. The experimental and the simulated data were fit to an interference measurement model to measure the tendency to confuse items with other items nearby on the list-the locality constraint-in people as well as in the models. The continuous-reproduction performance showed a pronounced primacy effect with no recency, as well as some evidence for transpositions obeying the locality constraint. Though not entirely conclusive, this evidence favors event-based models over a role for temporal distinctiveness. There was also a strong detrimental effect of articulatory suppression, suggesting that verbal codes can be used to support serial-order memory of simple visual stimuli.

  16. An amalgamation of 3D city models in urban air quality modelling for improving visual impact analysis

    DEFF Research Database (Denmark)

    Ujang, U.; Anton, F.; Ariffin, A.

    2015-01-01

    Geographical Information Systems (GISs) can be seen as a common tool to map and visualize the air quality index based on geographical locations. However, in urban areas, the area resolution for air quality models is less than 2 kilometres.Since the main emissions agent in urban areas...... as physical data input. The Level of Details (LoD) in 3D city models (i.e. LoD1 and LoD2) ascertains the potentials of implementing air quality modelling for urban areas. Therefore, this research is focused towards investigating the integration of 3D city models in air quality modelling for urban areas......,engineers and policy makers to design the street geometry (building height and width, green areas, pedestrian walks, roads width, etc.)....

  17. Development of a Quick Look Pandemic Influenza Modeling and Visualization Tool

    Energy Technology Data Exchange (ETDEWEB)

    Brigantic, Robert T.; Ebert, David S.; Corley, Courtney D.; Maciejewski, Ross; Muller, George; Taylor, Aimee E.

    2010-05-30

    Federal, State, and local decision makers and public health officials must prepare and exercise complex plans to contend with a variety of possible mass casualty events, such as pandemic influenza. Through the provision of quick look tools (QLTs) focused on mass casualty events, such planning can be done with higher accuracy and more realism through the combination of interactive simulation and visualization in these tools. If an event happens, the QLTs can then be employed to rapidly assess and execute alternative mitigation strategies, and thereby minimize casualties. This can be achieved by conducting numerous 'what-if' assessments prior to any event in order to assess potential health impacts (e.g., number of sick individuals), required community resources (e.g., vaccinations and hospital beds), and optimal mitigative decision strategies (e.g., school closures) during the course of a pandemic. In this presentation, we overview and demonstrate a pandemic influenza QLT, discuss some of the modeling methods and construct and visual analytic components and interface, and outline additional development concepts. These include the incorporation of a user selectable infectious disease palette, simultaneous visualization of decision alternatives, additional resource elements associated with emergency response (e.g., first responders and medical professionals), and provisions for other potential disaster events.

  18. A Neuro-Oncology Workstation for Structuring, Modeling, and Visualizing Patient Records.

    Science.gov (United States)

    Hsu, William; Arnold, Corey W; Taira, Ricky K

    2010-11-01

    The patient medical record contains a wealth of information consisting of prior observations, interpretations, and interventions that need to be interpreted and applied towards decisions regarding current patient care. Given the time constraints and the large-often extraneous-amount of data available, clinicians are tasked with the challenge of performing a comprehensive review of how a disease progresses in individual patients. To facilitate this process, we demonstrate a neuro-oncology workstation that assists in structuring and visualizing medical data to promote an evidence-based approach for understanding a patient's record. The workstation consists of three components: 1) a structuring tool that incorporates natural language processing to assist with the extraction of problems, findings, and attributes for structuring observations, events, and inferences stated within medical reports; 2) a data modeling tool that provides a comprehensive and consistent representation of concepts for the disease-specific domain; and 3) a visual workbench for visualizing, navigating, and querying the structured data to enable retrieval of relevant portions of the patient record. We discuss this workstation in the context of reviewing cases of glioblastoma multiforme patients.

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

    Science.gov (United States)

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

    2017-05-01

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

  20. A Joint Gaussian Process Model for Active Visual Recognition with Expertise Estimation in Crowdsourcing.

    Science.gov (United States)

    Long, Chengjiang; Hua, Gang; Kapoor, Ashish

    2016-01-01

    We present a noise resilient probabilistic model for active learning of a Gaussian process classifier from crowds, i.e., a set of noisy labelers. It explicitly models both the overall label noise and the expertise level of each individual labeler with two levels of flip models. Expectation propagation is adopted for efficient approximate Bayesian inference of our probabilistic model for classification, based on which, a generalized EM algorithm is derived to estimate both the global label noise and the expertise of each individual labeler. The probabilistic nature of our model immediately allows the adoption of the prediction entropy for active selection of data samples to be labeled, and active selection of high quality labelers based on their estimated expertise to label the data. We apply the proposed model for four visual recognition tasks, i.e., object category recognition, multi-modal activity recognition, gender recognition, and fine-grained classification, on four datasets with real crowd-sourced labels from the Amazon Mechanical Turk. The experiments clearly demonstrate the efficacy of the proposed model. In addition, we extend the proposed model with the Predictive Active Set Selection Method to speed up the active learning system, whose efficacy is verified by conducting experiments on the first three datasets. The results show our extended model can not only preserve a higher accuracy, but also achieve a higher efficiency.

  1. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity.

    Science.gov (United States)

    Ritchey, Eric R; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A; Petersen-Jones, Simon; Fischer, Andy J

    2012-09-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells (Ritchey et al., 2010). FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Matching-index-of-refraction of transparent 3D printing models for flow visualization

    Energy Technology Data Exchange (ETDEWEB)

    Song, Min Seop; Choi, Hae Yoon; Seong, Jee Hyun; Kim, Eung Soo, E-mail: kes7741@snu.ac.kr

    2015-04-01

    Matching-index-of-refraction (MIR) has been used for obtaining high-quality flow visualization data for the fundamental nuclear thermal-hydraulic researches. By this method, distortions of the optical measurements such as PIV and LDV have been successfully minimized using various combinations of the model materials and the working fluids. This study investigated a novel 3D printing technology for manufacturing models and an oil-based working fluid for matching the refractive indices. Transparent test samples were fabricated by various rapid prototyping methods including selective layer sintering (SLS), stereolithography (SLA), and vacuum casting. As a result, the SLA direct 3D printing was evaluated to be the most suitable for flow visualization considering manufacturability, transparency, and refractive index. In order to match the refractive indices of the 3D printing models, a working fluid was developed based on the mixture of herb essential oils, which exhibit high refractive index, high transparency, high density, low viscosity, low toxicity, and low price. The refractive index and viscosity of the working fluid range 1.453–1.555 and 2.37–6.94 cP, respectively. In order to validate the MIR method, a simple test using a twisted prism made by the SLA technique and the oil mixture (anise and light mineral oil) was conducted. The experimental results show that the MIR can be successfully achieved at the refractive index of 1.51, and the proposed MIR method is expected to be widely used for flow visualization studies and CFD validation for the nuclear thermal-hydraulic researches.

  3. Modeling and Visualizing the Particle Beam in the Rare Isotope Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Christopher [Argonne National Lab., IL (United States); Erdelyi, Bela [Argonne National Lab., IL (United States); Northern Illinois Univ. (United States)

    2006-01-01

    Argonne National Laboratory is actively pursuing research and design for a Rare Isotope Accelerator (RIA) facility that will aid basic research in nuclear physics by creating beams of unstable isotopes. Such a facility has been labeled as a high priority by the joint Department of Energy and National Science Foundation Nuclear Science Advisory Committee because it will allow more study on the nature of nucleonic matter, the origin of the elements, the Standard Model, and nuclear medicine. An important part of this research is computer simulations that model the behavior of the particle beam, specifically in the Fragment Separator. The Fragment Separator selects isotopes based on their trajectory in electromagnetic fields and then uses absorbers to separate particles with a certain mass and charge from the rest of the beam. This project focused on the development of a multivariate, correlated Gaussian distribution to model the distribution of particles in the beam as well as visualizations and analysis to view how this distribution changed when passing through an absorber. The distribution was developed in the COSY INFINITY programming language. The user inputs a covariance matrix and a vector of means for the six phase space variables, and the program outputs a vector of correlated, Gaussian random variables. A variety of random test cases were conducted in two, three and six variables. In each case, the expectation values, variances and covariances were calculated and they converged to the input values. The output of the absorber code is a large data set that stores all of the variables for each particle in the distribution. It is impossible to analyze such a large data set by hand, so visualizations and summary statistics had to be developed. The first visualization is a three-dimensional graph that shows the number of each isotope present after each slice of the absorber. A second graph plots any of the six phase space variables against any of the others to see

  4. Learning what to look in chest X-rays with a recurrent visual attention model

    OpenAIRE

    Ypsilantis, Petros-Pavlos; Montana, Giovanni

    2017-01-01

    X-rays are commonly performed imaging tests that use small amounts of radiation to produce pictures of the organs, tissues, and bones of the body. X-rays of the chest are used to detect abnormalities or diseases of the airways, blood vessels, bones, heart, and lungs. In this work we present a stochastic attention-based model that is capable of learning what regions within a chest X-ray scan should be visually explored in order to conclude that the scan contains a specific radiological abnorma...

  5. Application and study of 3D visualization model on nuclear power plant construction

    Science.gov (United States)

    Guo, Depeng; Pu, Chenghao; Li, Maolin; Zhang, Wenguang; Zhao, Jing; Arlia, Laura Alejandra

    2017-04-01

    3-D visualization model is an advanced tool which addresses a digital expression to the project entity and functional characteristics by integrating the relative engineering data. Construction units lead this technique in the equipment installation activities of the first unit of AP1000 Nuclear Power Plant Project in the world. 3-D technique proved its advantages in construction scheme preparation, second design, collision simulation, construction logic, etc. Through the introduction of the main characteristics and superiority of this technique, the solution and suggestions for some project insufficiencies have been proposed. This will represent a benefit for its application in the future.

  6. Visualizing Experimental Designs for Balanced ANOVA Models using Lisp-Stat

    Directory of Open Access Journals (Sweden)

    Philip W. Iversen

    2004-12-01

    Full Text Available The structure, or Hasse, diagram described by Taylor and Hilton (1981, American Statistician provides a visual display of the relationships between factors for balanced complete experimental designs. Using the Hasse diagram, rules exist for determining the appropriate linear model, ANOVA table, expected means squares, and F-tests in the case of balanced designs. This procedure has been implemented in Lisp-Stat using a software representation of the experimental design. The user can interact with the Hasse diagram to add, change, or delete factors and see the effect on the proposed analysis. The system has potential uses in teaching and consulting.

  7. Coupling Visualization, Simulation, and Deep Learning for Ensemble Steering of Complex Energy Models: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Kristin C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bugbee, Bruce [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnan, Venkat K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-09

    We have developed a framework for the exploration, design, and planning of energy systems that combines interactive visualization with machine-learning based approximations of simulations through a general purpose dataflow API. Our system provides a visual inter- face allowing users to explore an ensemble of energy simulations representing a subset of the complex input parameter space, and spawn new simulations to 'fill in' input regions corresponding to new enegery system scenarios. Unfortunately, many energy simula- tions are far too slow to provide interactive responses. To support interactive feedback, we are developing reduced-form models via machine learning techniques, which provide statistically sound esti- mates of the full simulations at a fraction of the computational cost and which are used as proxies for the full-form models. Fast com- putation and an agile dataflow enhance the engagement with energy simulations, and allow researchers to better allocate computational resources to capture informative relationships within the system and provide a low-cost method for validating and quality-checking large-scale modeling efforts.

  8. Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments.

    Science.gov (United States)

    Tünnermann, Jan; Krüger, Alexander; Scharlau, Ingrid

    2017-01-23

    This protocol describes how to conduct temporal-order experiments to measure visual processing speed and the attentional resource distribution. The proposed method is based on a new and synergistic combination of three components: the temporal-order judgments (TOJ) paradigm, Bundesen's Theory of Visual Attention (TVA), and a hierarchical Bayesian estimation framework. The method provides readily interpretable parameters, which are supported by the theoretical and neurophysiological underpinnings of TVA. Using TOJs, TVA-based estimates can be obtained for a broad range of stimuli, whereas traditional paradigms used with TVA are mainly limited to letters and digits. Finally, the meaningful parameters of the proposed model allow for the establishment of a hierarchical Bayesian model. Such a statistical model allows assessing results in one coherent analysis both on the subject and the group level. To demonstrate the feasibility and versatility of this new approach, three experiments are reported with attention manipulations in synthetic pop-out displays, natural images, and a cued letter-report paradigm.

  9. East China Sea Storm Surge Modeling and Visualization System: The Typhoon Soulik Case

    Directory of Open Access Journals (Sweden)

    Zengan Deng

    2014-01-01

    Full Text Available East China Sea (ECS Storm Surge Modeling System (ESSMS is developed based on Regional Ocean Modeling System (ROMS. Case simulation is performed on the Typhoon Soulik, which landed on the coastal region of Fujian Province, China, at 6 pm of July 13, 2013. Modeling results show that the maximum tide level happened at 6 pm, which was also the landing time of Soulik. This accordance may lead to significant storm surge and water level rise in the coastal region. The water level variation induced by high winds of Soulik ranges from −0.1 to 0.15 m. Water level generally increases near the landing place, in particular on the left hand side of the typhoon track. It is calculated that 0.15 m water level rise in this region can cause a submerge increase of ~0.2 km2, which could be catastrophic to the coastal environment and the living. Additionally, a Globe Visualization System (GVS is realized on the basis of World Wind to better provide users with the typhoon/storm surge information. The main functions of GVS include data indexing, browsing, analyzing, and visualization. GVS is capable of facilitating the precaution and mitigation of typhoon/storm surge in ESC in combination with ESSMS.

  10. NetLand: quantitative modeling and visualization of Waddington's epigenetic landscape using probabilistic potential.

    Science.gov (United States)

    Guo, Jing; Lin, Feng; Zhang, Xiaomeng; Tanavde, Vivek; Zheng, Jie

    2017-05-15

    Waddington's epigenetic landscape is a powerful metaphor for cellular dynamics driven by gene regulatory networks (GRNs). Its quantitative modeling and visualization, however, remains a challenge, especially when there are more than two genes in the network. A software tool for Waddington's landscape has not been available in the literature. We present NetLand, an open-source software tool for modeling and simulating the kinetic dynamics of GRNs, and visualizing the corresponding Waddington's epigenetic landscape in three dimensions without restriction on the number of genes in a GRN. With an interactive and graphical user interface, NetLand can facilitate the knowledge discovery and experimental design in the study of cell fate regulation (e.g. stem cell differentiation and reprogramming). NetLand can run under operating systems including Windows, Linux and OS X. The executive files and source code of NetLand as well as a user manual, example models etc. can be downloaded from http://netland-ntu.github.io/NetLand/ . zhengjie@ntu.edu.sg. Supplementary data are available at Bioinformatics online.

  11. Visual Basic, Excel-based fish population modeling tool - The pallid sturgeon example

    Science.gov (United States)

    Moran, Edward H.; Wildhaber, Mark L.; Green, Nicholas S.; Albers, Janice L.

    2016-02-10

    The model presented in this report is a spreadsheet-based model using Visual Basic for Applications within Microsoft Excel (http://dx.doi.org/10.5066/F7057D0Z) prepared in cooperation with the U.S. Army Corps of Engineers and U.S. Fish and Wildlife Service. It uses the same model structure and, initially, parameters as used by Wildhaber and others (2015) for pallid sturgeon. The difference between the model structure used for this report and that used by Wildhaber and others (2015) is that variance is not partitioned. For the model of this report, all variance is applied at the iteration and time-step levels of the model. Wildhaber and others (2015) partition variance into parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level and temporal variance (uncertainty caused by random environmental fluctuations with time) applied at the time-step level. They included implicit individual variance (uncertainty caused by differences between individuals) within the time-step level.The interface developed for the model of this report is designed to allow the user the flexibility to change population model structure and parameter values and uncertainty separately for every component of the model. This flexibility makes the modeling tool potentially applicable to any fish species; however, the flexibility inherent in this modeling tool makes it possible for the user to obtain spurious outputs. The value and reliability of the model outputs are only as good as the model inputs. Using this modeling tool with improper or inaccurate parameter values, or for species for which the structure of the model is inappropriate, could lead to untenable management decisions. By facilitating fish population modeling, this modeling tool allows the user to evaluate a range of management options and implications. The goal of this modeling tool is to be a user-friendly modeling tool for developing fish population models useful to natural resource

  12. Unsupervised knowledge structuring Application of Infinite Relational Models to the FCA visualization

    DEFF Research Database (Denmark)

    Glückstad, Fumiko Kano; Herlau, Tue; Schmidt, Mikkel Nørgaard

    2013-01-01

    This work presents a conceptual framework for learning an ontological structure of domain knowledge, which combines Jaccard similarity coefficient with the Infinite Relational Model (IRM) by (Kemp et al. 2006) and its extended model, i.e. the normal-Infinite Relational Model (n-IRM) by (Herlau et...... al. 2012). The proposed approach is applied to a dataset where legal concepts related to the Japanese educational system are defined by the Japanese authorities according to the International Standard Classification of Education (ISCED). Results indicate that the proposed approach effectively...... structures features for defining groups of concepts in several levels (i.e., concept, category, abstract category levels) from which an ontological structure is systematically visualized as a lattice graph based on the Formal Concept Analysis (FCA) by (Ganter and Wille 1997)....

  13. The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes.

    Science.gov (United States)

    Galeazzi, Juan M; Navajas, Joaquín; Mender, Bedeho M W; Quian Quiroga, Rodrigo; Minini, Loredana; Stringer, Simon M

    2016-01-01

    Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw. A camera mounted on the head captured images of the hand and jigsaw, while eye movements were recorded using an eye-tracking device. This combination of data allowed us to reconstruct the retinal images seen as humans undertook the jigsaw task. These retinal images were then fed into the neural network model during self-organization of its synaptic connectivity using a biologically plausible trace learning rule. A trace learning mechanism encourages neurons in the model to learn to respond to input images that tend to occur in close temporal proximity. In the data recorded from human subjects, we found that the participant's gaze often shifted through a sequence of locations around a fixed spatial configuration of the hand and one of the jigsaw pieces. In this case, trace learning should bind these retinal images together onto the same subset of output neurons. The simulation results consequently confirmed that some cells learned to respond selectively to the hand and a jigsaw piece in a fixed spatial configuration across different retinal views.

  14. Computational Modeling of Cephalad Fluid Shift for Application to Microgravity-Induced Visual Impairment

    Science.gov (United States)

    Nelson, Emily S.; Best, Lauren M.; Myers, Jerry G.; Mulugeta, Lealem

    2013-01-01

    An improved understanding of spaceflight-induced ocular pathology, including the loss of visual acuity, globe flattening, optic disk edema and distension of the optic nerve and optic nerve sheath, is of keen interest to space medicine. Cephalad fluid shift causes a profoundly altered distribution of fluid within the compartments of the head and body, and may indirectly generate phenomena that are biomechanically relevant to visual function, such as choroidal engorgement, compromised drainage of blood and cerebrospinal fluid (CSF), and altered translaminar pressure gradient posterior to the eye. The experimental body of evidence with respect to the consequences of fluid shift has not yet been able to provide a definitive picture of the sequence of events. On earth, elevated intracranial pressure (ICP) is associated with idiopathic intracranial hypertension (IIH), which can produce ocular pathologies that look similar to those seen in some astronauts returning from long-duration flight. However, the clinically observable features of the Visual Impairment and Intracranial Pressure (VIIP) syndrome in space and IIH on earth are not entirely consistent. Moreover, there are at present no experimental measurements of ICP in microgravity. By its very nature, physiological measurements in spaceflight are sparse, and the space environment does not lend itself to well-controlled experiments. In the absence of such data, numerical modeling can play a role in the investigation of biomechanical causal pathways that are suspected of involvement in VIIP. In this work, we describe the conceptual framework for modeling the altered compartmental fluid distribution that represents an equilibrium fluid distribution resulting from the loss of hydrostatic pressure gradient.

  15. Subtle alterations in memory systems and normal visual attention in the GAERS model of absence epilepsy.

    Science.gov (United States)

    Marques-Carneiro, J E; Faure, J-B; Barbelivien, A; Nehlig, A; Cassel, J-C

    2016-03-01

    Even if considered benign, absence epilepsy may alter memory and attention, sometimes subtly. Very little is known on behavior and cognitive functions in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model of absence epilepsy. We focused on different memory systems and sustained visual attention, using Non Epileptic Controls (NECs) and Wistars as controls. A battery of cognitive/behavioral tests was used. The functionality of reference, working, and procedural memory was assessed in the Morris water maze (MWM), 8-arm radial maze, T-maze and/or double-H maze. Sustained visual attention was evaluated in the 5-choice serial reaction time task. In the MWM, GAERS showed delayed learning and less efficient working memory. In the 8-arm radial maze and T-maze tests, working memory performance was normal in GAERS, although most GAERS preferred an egocentric strategy (based on proprioceptive/kinesthetic information) to solve the task, but could efficiently shift to an allocentric strategy (based on spatial cues) after protocol alteration. Procedural memory and visual attention were mostly unimpaired. Absence epilepsy has been associated with some learning problems in children. In GAERS, the differences in water maze performance (slower learning of the reference memory task and weak impairment of working memory) and in radial arm maze strategies suggest that cognitive alterations may be subtle, task-specific, and that normal performance can be a matter of strategy adaptation. Altogether, these results strengthen the "face validity" of the GAERS model: in humans with absence epilepsy, cognitive alterations are not easily detectable, which is compatible with subtle deficits. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Visualization of Stereoscopic Anatomic Models of the Paranasal Sinuses and Cervical Vertebrae from the Surgical and Procedural Perspective

    Science.gov (United States)

    Chen, Jian; Smith, Andrew D.; Khan, Majid A.; Sinning, Allan R.; Conway, Marianne L.; Cui, Dongmei

    Recent improvements in three-dimensional (3D) virtual modeling software allows anatomists to generate high-resolution, visually appealing, colored, anatomical 3D models from computed tomography (CT) images. In this study, high-resolution CT images of a cadaver were used to develop clinically relevant anatomic models including facial skull, nasal…

  17. Open source 3D visualization and interaction dedicated to hydrological models

    Science.gov (United States)

    Richard, Julien; Giangola-Murzyn, Agathe; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2014-05-01

    Climate change and surface urbanization strongly modify the hydrological cycle in urban areas, increasing the consequences of extreme events such as floods or draughts. These issues lead to the development of the Multi-Hydro model at the Ecole des Ponts ParisTech (A. Giangola-Murzyn et al., 2012). This fully distributed model allows to compute the hydrological response of urban and peri-urban areas. Unfortunately such models are seldom user friendly. Indeed generating the inputs before launching a new simulation is usually a tricky tasks, and understanding and interpreting the outputs remains specialist tasks not accessible to the wider public. The MH-AssimTool was developed to overcome these issues. To enable an easier and improved understanding of the model outputs, we decided to convert the raw output data (grids file in ascii format) to a 3D display. Some commercial paying models provide a 3D visualization. Because of the cost of their licenses, this kind of tools may not be accessible to the most concerned stakeholders. So, we are developing a new tool based on C++ for the computation, Qt for the graphic user interface, QGIS for the geographical side and OpenGL for the 3D display. All these languages and libraries are open source and multi-platform. We will discuss some preprocessing issues for the data conversion from 2.5D to 3D. Indeed, the GIS data, is considered as a 2.5D (e.i. 2D polygon + one height) and the its transform to 3D display implies a lot of algorithms. For example,to visualize in 3D one building, it is needed to have for each point the coordinates and the elevation according to the topography. Furthermore one have to create new points to represent the walls. Finally the interactions between the model and stakeholders through this new interface and how this helps converting a research tool into a an efficient operational decision tool will be discussed. This ongoing research on the improvement of the visualization methods is supported by the

  18. A Scalable Cloud Library Empowering Big Data Management, Diagnosis, and Visualization of Cloud-Resolving Models

    Science.gov (United States)

    Zhou, S.; Tao, W. K.; Li, X.; Matsui, T.; Sun, X. H.; Yang, X.

    2015-12-01

    A cloud-resolving model (CRM) is an atmospheric numerical model that can numerically resolve clouds and cloud systems at 0.25~5km horizontal grid spacings. The main advantage of the CRM is that it can allow explicit interactive processes between microphysics, radiation, turbulence, surface, and aerosols without subgrid cloud fraction, overlapping and convective parameterization. Because of their fine resolution and complex physical processes, it is challenging for the CRM community to i) visualize/inter-compare CRM simulations, ii) diagnose key processes for cloud-precipitation formation and intensity, and iii) evaluate against NASA's field campaign data and L1/L2 satellite data products due to large data volume (~10TB) and complexity of CRM's physical processes. We have been building the Super Cloud Library (SCL) upon a Hadoop framework, capable of CRM database management, distribution, visualization, subsetting, and evaluation in a scalable way. The current SCL capability includes (1) A SCL data model enables various CRM simulation outputs in NetCDF, including the NASA-Unified Weather Research and Forecasting (NU-WRF) and Goddard Cumulus Ensemble (GCE) model, to be accessed and processed by Hadoop, (2) A parallel NetCDF-to-CSV converter supports NU-WRF and GCE model outputs, (3) A technique visualizes Hadoop-resident data with IDL, (4) A technique subsets Hadoop-resident data, compliant to the SCL data model, with HIVE or Impala via HUE's Web interface, (5) A prototype enables a Hadoop MapReduce application to dynamically access and process data residing in a parallel file system, PVFS2 or CephFS, where high performance computing (HPC) simulation outputs such as NU-WRF's and GCE's are located. We are testing Apache Spark to speed up SCL data processing and analysis.With the SCL capabilities, SCL users can conduct large-domain on-demand tasks without downloading voluminous CRM datasets and various observations from NASA Field Campaigns and Satellite data to a

  19. EVALUATING A SEGMENTATION-RESISTANT CAPTCHA INSPIRED BY THE HUMAN VISUAL SYSTEM MODEL

    Directory of Open Access Journals (Sweden)

    Imran Moez Khan

    2011-10-01

    Full Text Available Visual CAPTCHAs are widely used these days on the Internet as a means of distinguishing between humans and computers. They help protect servers from being flooded by requests from malicious scripts. However, they are not very secure. Numerous image processing algorithms are able to discern the characters used in the CAPTCHAs. It has been suggested that CAPTCHAs can be made more secure if they are distorted in ways that makes segmentation difficult. However, out of all the reviewed distortions present in current CAPTCHAs there are none that allow for a high level of segmentation difficulty. Furthermore, CAPTCHAs also need to be used by humans who may not find certain distortions tolerable. Thus, the problem of selecting a good distortion becomes a tradeoff between user acceptability and computer solvability. It is hypothesized in this paper that rather than use low-level image distortions, optical distortions based on the Gestalt laws of perception that govern human visual system models should be applied. These distortions would ensure widespread user acceptability (as they are based on the internal workings of the HVS, and be very difficult for computers to solve (as HVS perception models have been difficult to implement in computers. This paper aims to explore the feasibility of employing Gestalt-inspired distortion in CAPTCHAs by first implementing a CAPTCHA cracker and then evaluating the performance of some manually generated Gestalt CAPTCHA’s against some existing CAPTCHAs.

  20. Environmental enrichment extends photoreceptor survival and visual function in a mouse model of retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Ilaria Barone

    Full Text Available Slow, progressive rod degeneration followed by cone death leading to blindness is the pathological signature of all forms of human retinitis pigmentosa (RP. Therapeutic schemes based on intraocular delivery of neuroprotective agents prolong the lifetime of photoreceptors and have reached the stage of clinical trial. The success of these approaches depends upon optimization of chronic supply and appropriate combination of factors. Environmental enrichment (EE, a novel neuroprotective strategy based on enhanced motor, sensory and social stimulation, has already been shown to exert beneficial effects in animal models of various disorders of the CNS, including Alzheimer and Huntington disease. Here we report the results of prolonged exposure of rd10 mice, a mutant strain undergoing progressive photoreceptor degeneration mimicking human RP, to such an enriched environment from birth. By means of microscopy of retinal tissue, electrophysiological recordings, visual behaviour assessment and molecular analysis, we show that EE considerably preserves retinal morphology and physiology as well as visual perception over time in rd10 mutant mice. We find that protective effects of EE are accompanied by increased expression of retinal mRNAs for CNTF and mTOR, both factors known as instrumental to photoreceptor survival. Compared to other rescue approaches used in similar animal models, EE is highly effective, minimally invasive and results into a long-lasting retinal protection. These results open novel perspectives of research pointing to environmental strategies as useful tools to extend photoreceptor survival.

  1. VISIBIOweb: visualization and layout services for BioPAX pathway models

    Science.gov (United States)

    Dilek, Alptug; Belviranli, Mehmet E.; Dogrusoz, Ugur

    2010-01-01

    With recent advancements in techniques for cellular data acquisition, information on cellular processes has been increasing at a dramatic rate. Visualization is critical to analyzing and interpreting complex information; representing cellular processes or pathways is no exception. VISIBIOweb is a free, open-source, web-based pathway visualization and layout service for pathway models in BioPAX format. With VISIBIOweb, one can obtain well-laid-out views of pathway models using the standard notation of the Systems Biology Graphical Notation (SBGN), and can embed such views within one's web pages as desired. Pathway views may be navigated using zoom and scroll tools; pathway object properties, including any external database references available in the data, may be inspected interactively. The automatic layout component of VISIBIOweb may also be accessed programmatically from other tools using Hypertext Transfer Protocol (HTTP). The web site is free and open to all users and there is no login requirement. It is available at: http://visibioweb.patika.org. PMID:20460470

  2. Hierarchical neural network model of the visual system determining figure/ground relation

    Science.gov (United States)

    Kikuchi, Masayuki

    2017-07-01

    One of the most important functions of the visual perception in the brain is figure/ground interpretation from input images. Figural region in 2D image corresponding to object in 3D space are distinguished from background region extended behind the object. Previously the author proposed a neural network model of figure/ground separation constructed on the standpoint that local geometric features such as curvatures and outer angles at corners are extracted and propagated along input contour in a single layer network (Kikuchi & Akashi, 2001). However, such a processing principle has the defect that signal propagation requires manyiterations despite the fact that actual visual system determines figure/ground relation within the short period (Zhou et al., 2000). In order to attain speed-up for determining figure/ground, this study incorporates hierarchical architecture into the previous model. This study confirmed the effect of the hierarchization as for the computation time by simulation. As the number of layers increased, the required computation time reduced. However, such speed-up effect was saturatedas the layers increased to some extent. This study attempted to explain this saturation effect by the notion of average distance between vertices in the area of complex network, and succeeded to mimic the saturation effect by computer simulation.

  3. Searching for targets in visual working memory: investigating a dimensional feature bundle (DFB) model.

    Science.gov (United States)

    Töllner, Thomas; Mink, Maurice; Müller, Hermann J

    2015-03-01

    The human visual working memory (WM) system enables us to store a limited amount of task-relevant visual information temporally in mind. One actively debated issue in cognitive neuroscience centers around the question of how this WM information is maintained. The currently dominant views advocated by prominent WM models hold that the units of memory are configured either as independent feature representations, integrated bound objects, or a combination of both. Here, we approached this issue by measuring lateralized brain electrical activity during a retro-cue paradigm, in order to track people's ability to access WM representations as a function of the dimensional relation between WM items and task settings. Both factors were revealed to selectively influence WM access: whereas cross relative to intradimensional WM targets gave rise to enhanced contralateral delay activity (CDA) amplitudes, localization relative to identification task demands yielded speeded CDA and manual response times. As these dimension-based findings are not reconcilable with contemporary feature- and/or object-based accounts, an alternative view that is based on the hierarchical feature-bundle model is proposed. We argue that WM units may consist of three hierarchically structured levels of representations, with an intermediate dimensionally organized level that mediates between top-level object and lower-level feature representations. © 2015 New York Academy of Sciences.

  4. Obtaining and Visualization of the Topological Functioning Model from the UML Model

    Directory of Open Access Journals (Sweden)

    Ovchinnikova Viktoria

    2015-12-01

    Full Text Available A domain model can provide compact information about its corresponding software system for business people. If the software system exists without its domain model and documentation it is time-consuming to understand its behavior and structure only from the code. Reverse Engineering (RE tools can be used for obtaining behavior and structure of the software system from source code. After that the domain model can be created. A short overview and an example of obtaining the domain model, Topological Functioning Model (TFM, from source code are provided in the paper. Positive and negative effects of the process of TFM backward derivation are also discussed.

  5. epidemix-An interactive multi-model application for teaching and visualizing infectious disease transmission.

    Science.gov (United States)

    Muellner, Ulrich; Fournié, Guillaume; Muellner, Petra; Ahlstrom, Christina; Pfeiffer, Dirk U

    2017-12-11

    Mathematical models of disease transmission are used to improve our understanding of patterns of infection and to identify factors influencing them. During recent public and animal health crises, such as pandemic influenza, Ebola, Zika, foot-and-mouth disease, models have made important contributions in addressing policy questions, especially through the assessment of the trajectory and scale of outbreaks, and the evaluation of control interventions. However, their mathematical formulation means that they may appear as a "black box" to those without the appropriate mathematical background. This may lead to a negative perception of their utility for guiding policy, and generate expectations, which are not in line with what these models can deliver. It is therefore important for policymakers, as well as public health and animal health professionals and researchers who collaborate with modelers and use results generated by these models for policy development or research purpose, to understand the key concepts and assumptions underlying these models. The software application epidemix (http://shinyapps.rvc.ac.uk) presented here aims to make mathematical models of disease transmission accessible to a wider audience of users. By developing a visual interface for a suite of eight models, users can develop an understanding of the impact of various modelling assumptions - especially mixing patterns - on the trajectory of an epidemic and the impact of control interventions, without having to directly deal with the complexity of mathematical equations and programming languages. Models are compartmental or individual-based, deterministic or stochastic, and assume homogeneous or heterogeneous-mixing patterns (with the probability of transmission depending on the underlying structure of contact networks, or the spatial distribution of hosts). This application is intended to be used by scientists teaching mathematical modelling short courses to non-specialists - including policy

  6. Modeling and analysis of visual digital impact model for a Chinese human thorax.

    Science.gov (United States)

    Zhu, Jin; Wang, Kai-Ming; Li, Shu; Liu, Hai-Yan; Jing, Xiao; Li, Xiao-Fang; Liu, Yi-He

    2017-01-01

    To establish a three-dimensional finite element model of the human chest for engineering research on individual protection. Computed tomography (CT) scanning data were used for three-dimensional reconstruction with the medical image reconstruction software Mimics. The finite element method (FEM) preprocessing software ANSYS ICEM CFD was used for cell mesh generation, and the relevant material behavior parameters of all of the model's parts were specified. The finite element model was constructed with the FEM software, and the model availability was verified based on previous cadaver experimental data. A finite element model approximating the anatomical structure of the human chest was established, and the model's simulation results conformed to the results of the cadaver experiment overall. Segment data of the human body and specialized software can be utilized for FEM model reconstruction to satisfy the need for numerical analysis of shocks to the human chest in engineering research on body mechanics.

  7. Adaptive hybrid likelihood model for visual tracking based on Gaussian particle filter

    Science.gov (United States)

    Wang, Yong; Tan, Yihua; Tian, Jinwen

    2010-07-01

    We present a new scheme based on multiple-cue integration for visual tracking within a Gaussian particle filter framework. The proposed method integrates the color, shape, and texture cues of an object to construct a hybrid likelihood model. During the measurement step, the likelihood model can be switched adaptively according to environmental changes, which improves the object representation to deal with the complex disturbances, such as appearance changes, partial occlusions, and significant clutter. Moreover, the confidence weights of the cues are adjusted online through the estimation using a particle filter, which ensures the tracking accuracy and reliability. Experiments are conducted on several real video sequences, and the results demonstrate that the proposed method can effectively track objects in complex scenarios. Compared with previous similar approaches through some quantitative and qualitative evaluations, the proposed method performs better in terms of tracking robustness and precision.

  8. Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

    Science.gov (United States)

    Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

    2015-01-01

    Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

  9. Why does a ball fall?: A new visualization for Einstein's model of gravity

    Science.gov (United States)

    Gould, Roy R.

    2016-05-01

    Many physics teachers seek a simple illustration of Einstein's model of gravity, suitable for the introductory physics classroom. In this article, we show that an ordinary wall map of the world can be used to contrast Newton's and Einstein's explanations for why a ball falls when released. Trajectories on the map are analogous to the trajectories of the ball through spacetime, because the geometry of the map is remarkably similar to the geometry of spacetime near Earth's surface. To aid in the pedagogy, we focus on the concept of scale rather than curvature. We show that, contrary to popular visualizations of Einstein's model, it is primarily the warping of time, not space, that causes a ball to fall, and we address the question of why we do not see the distortion of spacetime around us. Finally, we recover Newton's results for the falling ball from our geometrical treatment.

  10. Pengembangan Perangkat Pembelajaran mengacu Model Creative Problem Solving berbasis Somatic, Auditory, Visualization, Intellectually

    Directory of Open Access Journals (Sweden)

    Septiana Wijayanti

    2017-12-01

    Full Text Available This study aims to develop the valid, practical, and effective teaching instruments by using Creative Problem Solving (CPS learning model with Somatic, Auditory, Visualization, and Intellectually (SAVI based. This method of this study is R&D (Research and Development which uses 4 D (Define, Design, Develop, and Development learning model from Thiagarajan. But, this phase of the study is not spreading the developing result of the teaching instrument yet. The data collection techniques are teacher and students’ need questionnaire, observation sheet, interview, validation sheet, teacher and students’ response questionnaire, and the result test. This study produces learning instruments such as lesson plan (RPP, learning module, and students’ worksheet (LKS. The result of this study shows that 1 learning instruments by using CPS learning model with SAVI based such as lesson plan, learning module, and student’s worksheet includes in good category based on the expert judgement generally, 2 students and teacher’s response toward the learning by using CPS learning model with SAVI based show that they are interested in learning process, new learning model which is not used before, and they are also interested in the student’s worksheet and learning module, and 3 CPS learning model with SAVI based is effective to use in learning distance in space. From this result of the study, it can be concluded that the developed learning instrument is valid, practical, and effective.

  11. Meta-modelling, visualization and emulation of multi-dimensional data for virtual production intelligence

    Science.gov (United States)

    Schulz, Wolfgang; Hermanns, Torsten; Al Khawli, Toufik

    2017-07-01

    Decision making for competitive production in high-wage countries is a daily challenge where rational and irrational methods are used. The design of decision making processes is an intriguing, discipline spanning science. However, there are gaps in understanding the impact of the known mathematical and procedural methods on the usage of rational choice theory. Following Benjamin Franklin's rule for decision making formulated in London 1772, he called "Prudential Algebra" with the meaning of prudential reasons, one of the major ingredients of Meta-Modelling can be identified finally leading to one algebraic value labelling the results (criteria settings) of alternative decisions (parameter settings). This work describes the advances in Meta-Modelling techniques applied to multi-dimensional and multi-criterial optimization by identifying the persistence level of the corresponding Morse-Smale Complex. Implementations for laser cutting and laser drilling are presented, including the generation of fast and frugal Meta-Models with controlled error based on mathematical model reduction Reduced Models are derived to avoid any unnecessary complexity. Both, model reduction and analysis of multi-dimensional parameter space are used to enable interactive communication between Discovery Finders and Invention Makers. Emulators and visualizations of a metamodel are introduced as components of Virtual Production Intelligence making applicable the methods of Scientific Design Thinking and getting the developer as well as the operator more skilled.

  12. A reaction-diffusion model to capture disparity selectivity in primary visual cortex.

    Directory of Open Access Journals (Sweden)

    Mohammed Sultan Mohiuddin Siddiqui

    Full Text Available Decades of experimental studies are available on disparity selective cells in visual cortex of macaque and cat. Recently, local disparity map for iso-orientation sites for near-vertical edge preference is reported in area 18 of cat visual cortex. No experiment is yet reported on complete disparity map in V1. Disparity map for layer IV in V1 can provide insight into how disparity selective complex cell receptive field is organized from simple cell subunits. Though substantial amounts of experimental data on disparity selective cells is available, no model on receptive field development of such cells or disparity map development exists in literature. We model disparity selectivity in layer IV of cat V1 using a reaction-diffusion two-eye paradigm. In this model, the wiring between LGN and cortical layer IV is determined by resource an LGN cell has for supporting connections to cortical cells and competition for target space in layer IV. While competing for target space, the same type of LGN cells, irrespective of whether it belongs to left-eye-specific or right-eye-specific LGN layer, cooperate with each other while trying to push off the other type. Our model captures realistic 2D disparity selective simple cell receptive fields, their response properties and disparity map along with orientation and ocular dominance maps. There is lack of correlation between ocular dominance and disparity selectivity at the cell population level. At the map level, disparity selectivity topography is not random but weakly clustered for similar preferred disparities. This is similar to the experimental result reported for macaque. The details of weakly clustered disparity selectivity map in V1 indicate two types of complex cell receptive field organization.

  13. A hierarchical model of goal directed navigation selects trajectories in a visual environment.

    Science.gov (United States)

    Erdem, Uğur M; Milford, Michael J; Hasselmo, Michael E

    2015-01-01

    We have developed a Hierarchical Look-Ahead Trajectory Model (HiLAM) that incorporates the firing pattern of medial entorhinal grid cells in a planning circuit that includes interactions with hippocampus and prefrontal cortex. We show the model's flexibility in representing large real world environments using odometry information obtained from challenging video sequences. We acquire the visual data from a camera mounted on a small tele-operated vehicle. The camera has a panoramic field of view with its focal point approximately 5 cm above the ground level, similar to what would be expected from a rat's point of view. Using established algorithms for calculating perceptual speed from the apparent rate of visual change over time, we generate raw dead reckoning information which loses spatial fidelity over time due to error accumulation. We rectify the loss of fidelity by exploiting the loop-closure detection ability of a biologically inspired, robot navigation model termed RatSLAM. The rectified motion information serves as a velocity input to the HiLAM to encode the environment in the form of grid cell and place cell maps. Finally, we show goal directed path planning results of HiLAM in two different environments, an indoor square maze used in rodent experiments and an outdoor arena more than two orders of magnitude larger than the indoor maze. Together these results bridge for the first time the gap between higher fidelity bio-inspired navigation models (HiLAM) and more abstracted but highly functional bio-inspired robotic mapping systems (RatSLAM), and move from simulated environments into real-world studies in rodent-sized arenas and beyond. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. A Hybrid LDA+gCCA Model for fMRI Data Classification and Visualization.

    Science.gov (United States)

    Afshin-Pour, Babak; Shams, Seyed-Mohammad; Strother, Stephen

    2015-05-01

    Linear predictive models are applied to functional MRI (fMRI) data to estimate boundaries that predict experimental task states for scans. These boundaries are visualized as statistical parametric maps (SPMs) and range from low to high spatial reproducibility across subjects (e.g., Strother , 2004; LaConte , 2003). Such inter-subject pattern reproducibility is an essential characteristic of interpretable SPMs that generalize across subjects. Therefore, we introduce a flexible hybrid model that optimizes reproducibility by simultaneously enhancing the prediction power and reproducibility. This hybrid model is formed by a weighted summation of the optimization functions of a linear discriminate analysis (LDA) model and a generalized canonical correlation (gCCA) model (Afshin-Pour , 2012). LDA preserves the model's ability to discriminate the fMRI scans of multiple brain states while gCCA finds a linear combination for each subject's scans such that the estimated boundary map is reproducible. The hybrid model is implemented in a split-half resampling framework (Strother , 2010) which provides reproducibility (r) and prediction (p) quality metrics. Then the model was compared with LDA, and Gaussian Naive Bayes (GNB). For simulated fMRI data, the hybrid model outperforms the other two techniques in terms of receiver operating characteristic (ROC) curves, particularly for detecting less predictable but spatially reproducible networks. These techniques were applied to real fMRI data to estimate the maps for two task contrasts. Our results indicate that compared to LDA and GNB, the hybrid model can provide maps with large increases in reproducibility for small reductions in prediction, which are jointly closer to the ideal performance point of (p=1, r=1).

  15. Onboard Robust Visual Tracking for UAVs Using a Reliable Global-Local Object Model

    Directory of Open Access Journals (Sweden)

    Changhong Fu

    2016-08-01

    Full Text Available In this paper, we present a novel onboard robust visual algorithm for long-term arbitrary 2D and 3D object tracking using a reliable global-local object model for unmanned aerial vehicle (UAV applications, e.g., autonomous tracking and chasing a moving target. The first main approach in this novel algorithm is the use of a global matching and local tracking approach. In other words, the algorithm initially finds feature correspondences in a way that an improved binary descriptor is developed for global feature matching and an iterative Lucas–Kanade optical flow algorithm is employed for local feature tracking. The second main module is the use of an efficient local geometric filter (LGF, which handles outlier feature correspondences based on a new forward-backward pairwise dissimilarity measure, thereby maintaining pairwise geometric consistency. In the proposed LGF module, a hierarchical agglomerative clustering, i.e., bottom-up aggregation, is applied using an effective single-link method. The third proposed module is a heuristic local outlier factor (to the best of our knowledge, it is utilized for the first time to deal with outlier features in a visual tracking application, which further maximizes the representation of the target object in which we formulate outlier feature detection as a binary classification problem with the output features of the LGF module. Extensive UAV flight experiments show that the proposed visual tracker achieves real-time frame rates of more than thirty-five frames per second on an i7 processor with 640 × 512 image resolution and outperforms the most popular state-of-the-art trackers favorably in terms of robustness, efficiency and accuracy.

  16. Image Processing Strategies Based on a Visual Saliency Model for Object Recognition Under Simulated Prosthetic Vision.

    Science.gov (United States)

    Wang, Jing; Li, Heng; Fu, Weizhen; Chen, Yao; Li, Liming; Lyu, Qing; Han, Tingting; Chai, Xinyu

    2016-01-01

    Retinal prostheses have the potential to restore partial vision. Object recognition in scenes of daily life is one of the essential tasks for implant wearers. Still limited by the low-resolution visual percepts provided by retinal prostheses, it is important to investigate and apply image processing methods to convey more useful visual information to the wearers. We proposed two image processing strategies based on Itti's visual saliency map, region of interest (ROI) extraction, and image segmentation. Itti's saliency model generated a saliency map from the original image, in which salient regions were grouped into ROI by the fuzzy c-means clustering. Then Grabcut generated a proto-object from the ROI labeled image which was recombined with background and enhanced in two ways--8-4 separated pixelization (8-4 SP) and background edge extraction (BEE). Results showed that both 8-4 SP and BEE had significantly higher recognition accuracy in comparison with direct pixelization (DP). Each saliency-based image processing strategy was subject to the performance of image segmentation. Under good and perfect segmentation conditions, BEE and 8-4 SP obtained noticeably higher recognition accuracy than DP, and under bad segmentation condition, only BEE boosted the performance. The application of saliency-based image processing strategies was verified to be beneficial to object recognition in daily scenes under simulated prosthetic vision. They are hoped to help the development of the image processing module for future retinal prostheses, and thus provide more benefit for the patients. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. Can two established information models explain the information behaviour of visually impaired people seeking health and social care information?

    OpenAIRE

    Beverley, C.A.; Bath, P.A.; Barber, R.

    2007-01-01

    Purpose – The purpose of this study is to determine the extent to which two existing models of information behaviour could explain the information behaviour of visually impaired people seeking health and social care information.\\ud \\ud Design/methodology/approach – The research was conducted within a constructivist paradigm. A total of 28 semi-structured interviews (face-to-face or telephone) with 31 visually impaired people were conducted. Framework analysis was used to analyse the results.\\...

  18. PhenoLines: Phenotype Comparison Visualizations for Disease Subtyping via Topic Models.

    Science.gov (United States)

    Glueck, Michael; Naeini, Mahdi Pakdaman; Doshi-Velez, Finale; Chevalier, Fanny; Khan, Azam; Wigdor, Daniel; Brudno, Michael

    2018-01-01

    PhenoLines is a visual analysis tool for the interpretation of disease subtypes, derived from the application of topic models to clinical data. Topic models enable one to mine cross-sectional patient comorbidity data (e.g., electronic health records) and construct disease subtypes-each with its own temporally evolving prevalence and co-occurrence of phenotypes-without requiring aligned longitudinal phenotype data for all patients. However, the dimensionality of topic models makes interpretation challenging, and de facto analyses provide little intuition regarding phenotype relevance or phenotype interrelationships. PhenoLines enables one to compare phenotype prevalence within and across disease subtype topics, thus supporting subtype characterization, a task that involves identifying a proposed subtype's dominant phenotypes, ages of effect, and clinical validity. We contribute a data transformation workflow that employs the Human Phenotype Ontology to hierarchically organize phenotypes and aggregate the evolving probabilities produced by topic models. We introduce a novel measure of phenotype relevance that can be used to simplify the resulting topology. The design of PhenoLines was motivated by formative interviews with machine learning and clinical experts. We describe the collaborative design process, distill high-level tasks, and report on initial evaluations with machine learning experts and a medical domain expert. These results suggest that PhenoLines demonstrates promising approaches to support the characterization and optimization of topic models.

  19. Semi-parametric regression model for survival data: graphical visualization with R.

    Science.gov (United States)

    Zhang, Zhongheng

    2016-12-01

    Cox proportional hazards model is a semi-parametric model that leaves its baseline hazard function unspecified. The rationale to use Cox proportional hazards model is that (I) the underlying form of hazard function is stringent and unrealistic, and (II) researchers are only interested in estimation of how the hazard changes with covariate (relative hazard). Cox regression model can be easily fit with coxph() function in survival package. Stratified Cox model may be used for covariate that violates the proportional hazards assumption. The relative importance of covariates in population can be examined with the rankhazard package in R. Hazard ratio curves for continuous covariates can be visualized using smoothHR package. This curve helps to better understand the effects that each continuous covariate has on the outcome. Population attributable fraction is a classic quantity in epidemiology to evaluate the impact of risk factor on the occurrence of event in the population. In survival analysis, the adjusted/unadjusted attributable fraction can be plotted against survival time to obtain attributable fraction function.

  20. Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization.

    Science.gov (United States)

    Cui, Dongmei; Lynch, James C; Smith, Andrew D; Wilson, Timothy D; Lehman, Michael N

    2016-01-01

    Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin. © 2015 American Association of Anatomists.

  1. Vector Flow Visualization of Urinary Flow Dynamics in a Bladder Outlet Obstruction Model.

    Science.gov (United States)

    Ishii, Takuro; Yiu, Billy Y S; Yu, Alfred C H

    2017-11-01

    Voiding dysfunction that results from bladder outlet (BO) obstruction is known to alter significantly the dynamics of urine passage through the urinary tract. To non-invasively image this phenomenon on a time-resolved basis, we pursued the first application of a recently developed flow visualization technique called vector projectile imaging (VPI) that can track the spatiotemporal dynamics of flow vector fields at a frame rate of 10,000 fps (based on plane wave excitation and least-squares Doppler vector estimation principles). For this investigation, we designed a new anthropomorphic urethral tract phantom to reconstruct urinary flow dynamics under controlled conditions (300 mm H2O inlet pressure and atmospheric outlet pressure). Both a normal model and a diseased model with BO obstruction were developed for experimentation. VPI cine loops were derived from these urinary flow phantoms. Results show that VPI is capable of depicting differences in the flow dynamics of normal and diseased urinary tracts. In the case with BO obstruction, VPI depicted the presence of BO flow jet and vortices in the prostatic urethra. The corresponding spatial-maximum flow velocity magnitude was estimated to be 2.43 m/s, and it is significantly faster than that for the normal model (1.52 m/s) and is in line with values derived from computational fluid dynamics simulations. Overall, this investigation demonstrates the feasibility of using vector flow visualization techniques to non-invasively examine internal flow characteristics related to voiding dysfunction in the urethral tract. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Ultrasound-based Relative Elastic Modulus Imaging for Visualizing Thermal Ablation Zones in a Porcine Model

    Science.gov (United States)

    Jiang, Jingfeng; Brace, Chris; Andreano, Anita; DeWall, Ryan J.; Rubert, Nick; Fisher, Ted G.; Varghese, Tomy; Lee, Fred; Hall, Timothy J.

    2010-01-01

    The feasibility of using ultrasound-based elastic modulus imaging to visualize thermal ablation zones in an in vivo porcine model is reported in this article. Elastic modulus images of soft tissues are estimated as an inverse optimization problem. Ultrasonically-measured displacement data are utilized as inputs to determine an elastic modulus distribution that provides the best match to this displacement field. A total of 14 in vivo thermal ablation zones were investigated in this study. To determine the accuracy of delineation of each thermal ablation zone using elastic modulus imaging, the dimensions (lengths of long and short axes) and the are of each thermal ablation zone obtained from an elastic modulus image was compared to the corresponding gross pathology photograph of the same ablation zone. Comparison of elastic modulus imaging measurements and gross pathology measurements showed high correlation with respect to the area of thermal ablation zones (Pearson coefficient = 0.950 and pelastic modulus imaging can more accurately depict thermal ablation zones, when compared to strain imaging (14.7% versus 22.3% absolute percent error in area measurements, respectively). Furthermore, elastic modulus imaging also provide higher (more than a factor of two) contrast-to-noise ratios for evaluating these thermal ablation zones than those on corresponding strain images, thereby reducing inter-observer variability. Our preliminary results suggest that elastic modulus imaging might potentially enhance the ability to visualize thermal ablation zones, thereby improving assessment of ablative therapies. PMID:20354279

  3. Visual deficits in amblyopia constrain normal models of second-order motion processing.

    Science.gov (United States)

    Simmers, A J; Ledgeway, T; Hutchinson, C V; Knox, P J

    2011-09-15

    It is well established that amblyopes exhibit deficits in processing first-order (luminance-defined) patterns. This is readily manifest by measuring spatiotemporal sensitivity (i.e. the "window of visibility") to moving luminance gratings. However the window of visibility to moving second-order (texture-defined) patterns has not been systematically studied in amblyopia. To address this issue monocular modulation sensitivity (1/threshold) to first-order motion and four different varieties of second-order motion (modulations of either the contrast, flicker, size or orientation of visual noise) was measured over a five-octave range of spatial and temporal frequencies. Compared to normals amblyopes are not only impaired in the processing of first-order motion, but overall they exhibit both higher thresholds and a much narrower window of visibility to second-order images. However amblyopia can differentially impair the perception of some types of second-order motion much more than others and crucially the precise pattern of deficits varies markedly between individuals (even for those with the same conventional visual acuity measures). For the most severely impaired amblyopes certain second-order (texture) cues to movement in the environment are effectively invisible. These results place important constraints on the possible architecture of models of second-order motion perception in human vision. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Direct Visualization of Spatial and Temporal Patterns of Antimicrobial Action within Model Oral Biofilms▿

    Science.gov (United States)

    Takenaka, Shoji; Trivedi, Harsh M.; Corbin, Audrey; Pitts, Betsey; Stewart, Philip S.

    2008-01-01

    A microscopic method for noninvasively visualizing the action of an antimicrobial agent inside a biofilm was developed and applied to describe spatial and temporal patterns of mouthrinse activity on model oral biofilms. Three species biofilms of Streptococcus oralis, Streptococcus gordonii, and Actinomyces naeslundii were grown in glass capillary flow cells. Bacterial cells were stained with the fluorogenic esterase substrate Calcien AM (CAM). Loss of green fluorescence upon exposure to an antimicrobial formulation was subsequently imaged by time-lapse confocal laser scanning microscopy. When an antimicrobial mouthrinse containing chlorhexidine digluconate was administered, a gradual loss of green fluorescence was observed that began at the periphery of cell clusters where they adjoined the flowing bulk fluid and progressed inward over a time period of several minutes. Image analysis was performed to quantify a penetration velocity of 4 μm/min. An enzyme-based antimicrobial formulation led to a gradual, continually slowing loss of fluorescence in a pattern that was qualitatively different from the behavior observed with chlorhexidine. Ethanol at 11.6% had little effect on the biofilm. None of these treatments resulted in the removal of biomass from the biofilm. Most methods to measure or visualize antimicrobial action in biofilms are destructive. Spatial information is important because biofilms are known for their structural and physiological heterogeneity. The CAM staining technique has the potential to provide information about the rate of antimicrobial penetration, the presence of tolerant subpopulations, and the extent of biomass removal effected by a treatment. PMID:18223108

  5. Griffiths phase and long-range correlations in a biologically motivated visual cortex model

    Science.gov (United States)

    Girardi-Schappo, M.; Bortolotto, G. S.; Gonsalves, J. J.; Pinto, L. T.; Tragtenberg, M. H. R.

    2016-07-01

    Activity in the brain propagates as waves of firing neurons, namely avalanches. These waves’ size and duration distributions have been experimentally shown to display a stable power-law profile, long-range correlations and 1/f b power spectrum in vivo and in vitro. We study an avalanching biologically motivated model of mammals visual cortex and find an extended critical-like region - a Griffiths phase - characterized by divergent susceptibility and zero order parameter. This phase lies close to the expected experimental value of the excitatory postsynaptic potential in the cortex suggesting that critical be-havior may be found in the visual system. Avalanches are not perfectly power-law distributed, but it is possible to collapse the distributions and define a cutoff avalanche size that diverges as the network size is increased inside the critical region. The avalanches present long-range correlations and 1/f b power spectrum, matching experiments. The phase transition is analytically determined by a mean-field approximation.

  6. Model-driven design for the visual analysis of heterogeneous data.

    Science.gov (United States)

    Streit, Marc; Schulz, Hans-Jörg; Lex, Alexander; Schmalstieg, Dieter; Schumann, Heidrun

    2012-06-01

    As heterogeneous data from different sources are being increasingly linked, it becomes difficult for users to understand how the data are connected, to identify what means are suitable to analyze a given data set, or to find out how to proceed for a given analysis task. We target this challenge with a new model-driven design process that effectively codesigns aspects of data, view, analytics, and tasks. We achieve this by using the workflow of the analysis task as a trajectory through data, interactive views, and analytical processes. The benefits for the analysis session go well beyond the pure selection of appropriate data sets and range from providing orientation or even guidance along a preferred analysis path to a potential overall speedup, allowing data to be fetched ahead of time. We illustrate the design process for a biomedical use case that aims at determining a treatment plan for cancer patients from the visual analysis of a large, heterogeneous clinical data pool. As an example for how to apply the comprehensive design approach, we present Stack'n'flip, a sample implementation which tightly integrates visualizations of the actual data with a map of available data sets, views, and tasks, thus capturing and communicating the analytical workflow through the required data sets.

  7. Practical Stabilization of Uncertain Nonholonomic Mobile Robots Based on Visual Servoing Model with Uncalibrated Camera Parameters

    Directory of Open Access Journals (Sweden)

    Hua Chen

    2013-01-01

    Full Text Available The practical stabilization problem is addressed for a class of uncertain nonholonomic mobile robots with uncalibrated visual parameters. Based on the visual servoing kinematic model, a new switching controller is presented in the presence of parametric uncertainties associated with the camera system. In comparison with existing methods, the new design method is directly used to control the original system without any state or input transformation, which is effective to avoid singularity. Under the proposed control law, it is rigorously proved that all the states of closed-loop system can be stabilized to a prescribed arbitrarily small neighborhood of the zero equilibrium point. Furthermore, this switching control technique can be applied to solve the practical stabilization problem of a kind of mobile robots with uncertain parameters (and angle measurement disturbance which appeared in some literatures such as Morin et al. (1998, Hespanha et al. (1999, Jiang (2000, and Hong et al. (2005. Finally, the simulation results show the effectiveness of the proposed controller design approach.

  8. Activity-Dependent Dysfunction in Visual and Olfactory Sensory Systems in Mouse Models of Down Syndrome.

    Science.gov (United States)

    William, Christopher M; Saqran, Lubna; Stern, Matthew A; Chiang, Charles L; Herrick, Scott P; Rangwala, Aziz; Albers, Mark W; Frosch, Matthew P; Hyman, Bradley T

    2017-10-11

    Activity-dependent synaptic plasticity plays a critical role in the refinement of circuitry during postnatal development and may be disrupted in conditions that cause intellectual disability, such as Down syndrome (DS). To test this hypothesis, visual cortical plasticity was assessed in Ts65Dn mice that harbor a chromosomal duplication syntenic to human chromosome 21q. We find that Ts65Dn mice demonstrate a defect in ocular dominance plasticity (ODP) following monocular deprivation. This phenotype is similar to that of transgenic mice that express amyloid precursor protein (APP), which is duplicated in DS and in Ts65DN mice; however, normalizing APP gene copy number in Ts65Dn mice fails to rescue plasticity. Ts1Rhr mice harbor a duplication of the telomeric third of the Ts65Dn-duplicated sequence and demonstrate the same ODP defect, suggesting a gene or genes sufficient to drive the phenotype are located in that smaller duplication. In addition, we find that Ts65Dn mice demonstrate an abnormality in olfactory system connectivity, a defect in the refinement of connections to second-order neurons in the olfactory bulb. Ts1Rhr mice do not demonstrate a defect in glomerular refinement, suggesting that distinct genes or sets of genes underlie visual and olfactory system phenotypes. Importantly, these data suggest that developmental plasticity and connectivity are impaired in sensory systems in DS model mice, that such defects may contribute to functional impairment in DS, and that these phenotypes, present in male and female mice, provide novel means for examining the genetic and molecular bases for neurodevelopmental impairment in model mice in vivoSIGNIFICANCE STATEMENT Our understanding of the basis for intellectual impairment in Down syndrome is hindered by the large number of genes duplicated in Trisomy 21 and a lack of understanding of the effect of disease pathology on the function of neural circuits in vivo This work describes early postnatal developmental

  9. Visual cognition.

    Science.gov (United States)

    Cavanagh, Patrick

    2011-07-01

    Visual cognition, high-level vision, mid-level vision and top-down processing all refer to decision-based scene analyses that combine prior knowledge with retinal input to generate representations. The label "visual cognition" is little used at present, but research and experiments on mid- and high-level, inference-based vision have flourished, becoming in the 21st century a significant, if often understated part, of current vision research. How does visual cognition work? What are its moving parts? This paper reviews the origins and architecture of visual cognition and briefly describes some work in the areas of routines, attention, surfaces, objects, and events (motion, causality, and agency). Most vision scientists avoid being too explicit when presenting concepts about visual cognition, having learned that explicit models invite easy criticism. What we see in the literature is ample evidence for visual cognition, but few or only cautious attempts to detail how it might work. This is the great unfinished business of vision research: at some point we will be done with characterizing how the visual system measures the world and we will have to return to the question of how vision constructs models of objects, surfaces, scenes, and events. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. A Comparison between Elementary School Students' Mental Models and Visualizations in Textbooks for the Concept of Atom

    Science.gov (United States)

    Polat-Yaseen, Zeynep

    2012-01-01

    This study was designed for two major goals, which are to describe students' mental models about atom concept from 6th to 8th grade and to compare students' mental models with visual representations of atom in textbooks. Qualitative and quantitative data were collected with 4 open-ended questions including drawings which were quantified using the…

  11. Zebrafish (Danio rerio) as a model to visualize infection dynamics of Vibrio anguillarum following intraperitoneal injection and bath exposure

    DEFF Research Database (Denmark)

    Schmidt, Jacob Günther; Korbut, Rozalia; Ohtani, Maki

    2017-01-01

    , for which the vaccines are targeted. The zebrafish is by now a well established practical vertebrate model species due in part to its size and ease of maintenance and genetic manipulation. Here we use zebrafish as a model to visualize and compare the development of infection of Vibrio anguillarum...

  12. Visual Confidence.

    Science.gov (United States)

    Mamassian, Pascal

    2016-10-14

    Visual confidence refers to an observer's ability to judge the accuracy of her perceptual decisions. Even though confidence judgments have been recorded since the early days of psychophysics, only recently have they been recognized as essential for a deeper understanding of visual perception. The reluctance to study visual confidence may have come in part from obtaining convincing experimental evidence in favor of metacognitive abilities rather than just perceptual sensitivity. Some effort has thus been dedicated to offer different experimental paradigms to study visual confidence in humans and nonhuman animals. To understand the origins of confidence judgments, investigators have developed two competing frameworks. The approach based on signal decision theory is popular but fails to account for response times. In contrast, the approach based on accumulation of evidence models naturally includes the dynamics of perceptual decisions. These models can explain a range of results, including the apparently paradoxical dissociation between performance and confidence that is sometimes observed.

  13. Flow visualization of the wake of a transport aircraft model with lateral-control oscillations

    Science.gov (United States)

    Jordan, F. L., Jr.

    1983-01-01

    An exploratory flow visualization study conducted in the Langley Vortex Research Facility to investigate the effectiveness of lateral control surface oscillations as a potential method for wake vortex attenuation on a 0.03 scale model of a wide body jet transport aircraft is described. Effects of both asymmetric surface oscillation (control surfaces move as with normal lateral control inputs) and symmetric surface oscillation (control surfaces move in phase) are presented. The asymmetric case simulated a flight maneuver which was previously investigated on the transport aircraft during NASA/FAA flight tests and which resulted in substantial wake vortex attenuation. Effects on the model wake vortex systems were observed by propelling the model through a two dimensional smoke screen perpendicular to the model flight path. Results are presented as photographic time histories of the wake characteristics recorded with high speed still cameras. Effects of oscillation on the wake roll up are described in some detail, and the amount of vortex attenuation observed is discussed in comparative terms. Findings were consistent with flight test results in that only a small amount of rotation was observed in the wake for the asymmetric case. A possible aerodynamic mechanism contributing to this attenuation is suggested.

  14. Object Tracking Using Adaptive Covariance Descriptor and Clustering-Based Model Updating for Visual Surveillance

    Directory of Open Access Journals (Sweden)

    Lei Qin

    2014-05-01

    Full Text Available We propose a novel approach for tracking an arbitrary object in video sequences for visual surveillance. The first contribution of this work is an automatic feature extraction method that is able to extract compact discriminative features from a feature pool before computing the region covariance descriptor. As the feature extraction method is adaptive to a specific object of interest, we refer to the region covariance descriptor computed using the extracted features as the adaptive covariance descriptor. The second contribution is to propose a weakly supervised method for updating the object appearance model during tracking. The method performs a mean-shift clustering procedure among the tracking result samples accumulated during a period of time and selects a group of reliable samples for updating the object appearance model. As such, the object appearance model is kept up-to-date and is prevented from contamination even in case of tracking mistakes. We conducted comparing experiments on real-world video sequences, which confirmed the effectiveness of the proposed approaches. The tracking system that integrates the adaptive covariance descriptor and the clustering-based model updating method accomplished stable object tracking on challenging video sequences.

  15. Deep Learning Guided Partitioned Shape Model for Anterior Visual Pathway Segmentation.

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J; Idrees, Rabia; Biggs, Elijah; Alsharid, Mohammad A; Avery, Robert A; Linguraru, Marius George

    2016-08-01

    Analysis of cranial nerve systems, such as the anterior visual pathway (AVP), from MRI sequences is challenging due to their thin long architecture, structural variations along the path, and low contrast with adjacent anatomic structures. Segmentation of a pathologic AVP (e.g., with low-grade gliomas) poses additional challenges. In this work, we propose a fully automated partitioned shape model segmentation mechanism for AVP steered by multiple MRI sequences and deep learning features. Employing deep learning feature representation, this framework presents a joint partitioned statistical shape model able to deal with healthy and pathological AVP. The deep learning assistance is particularly useful in the poor contrast regions, such as optic tracts and pathological areas. Our main contributions are: 1) a fast and robust shape localization method using conditional space deep learning, 2) a volumetric multiscale curvelet transform-based intensity normalization method for robust statistical model, and 3) optimally partitioned statistical shape and appearance models based on regional shape variations for greater local flexibility. Our method was evaluated on MRI sequences obtained from 165 pediatric subjects. A mean Dice similarity coefficient of 0.779 was obtained for the segmentation of the entire AVP (optic nerve only =0.791 ) using the leave-one-out validation. Results demonstrated that the proposed localized shape and sparse appearance-based learning approach significantly outperforms current state-of-the-art segmentation approaches and is as robust as the manual segmentation.

  16. Fusing visual and behavioral cues for modeling user experience in games.

    Science.gov (United States)

    Shaker, Noor; Asteriadis, Stylianos; Yannakakis, Georgios N; Karpouzis, Kostas

    2013-12-01

    Estimating affective and cognitive states in conditions of rich human-computer interaction, such as in games, is a field of growing academic and commercial interest. Entertainment and serious games can benefit from recent advances in the field as, having access to predictors of the current state of the player (or learner) can provide useful information for feeding adaptation mechanisms that aim to maximize engagement or learning effects. In this paper, we introduce a large data corpus derived from 58 participants that play the popular Super Mario Bros platform game and attempt to create accurate models of player experience for this game genre. Within the view of the current research, features extracted both from player gameplay behavior and game levels, and player visual characteristics have been used as potential indicators of reported affect expressed as pairwise preferences between different game sessions. Using neuroevolutionary preference learning and automatic feature selection, highly accurate models of reported engagement, frustration, and challenge are constructed (model accuracies reach 91%, 92%, and 88% for engagement, frustration, and challenge, respectively). As a step further, the derived player experience models can be used to personalize the game level to desired levels of engagement, frustration, and challenge as game content is mapped to player experience through the behavioral and expressivity patterns of each player.

  17. Dissociating models of visual working memory by reaction-time distribution analysis.

    Science.gov (United States)

    Park, Hyung-Bum; Zhang, Weiwei; Hyun, Joo-Seok

    2017-02-01

    There have been heated debates on whether visual working memory (VWM) represents information in discrete-slots or a reservoir of flexible-resources. However, one key aspect of the models has gone unnoticed, the speed of processing when stored information in memory is assessed for accuracy. The present study evaluated contrasting predictions from the two models regarding the change detection decision times spent on the assessment of stored information by estimating the ex-Gaussian parameters from change detection RT distributions across different set sizes (2, 4, 6, or 8). The estimation showed that the Gaussian components μ and σ became larger as the set size increased from 2 to 4, but stayed constant as it reached 6 and 8, with an exponential component τ increasing at above-capacity set sizes. Moreover, we found that an individual's capacity limit correlates with the memory set size where the Gaussian μ reaches a plateau. These results indicate that the decision time for assessing in-memory items is constant regardless of memory set sizes whereas the time for the remaining not-in-memory items increases as the set size exceeds VWM storage capacity. The findings suggest that the discrete-slot model explains the observed RT distributions better than the flexible-resource model. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Fechner's law in metacognition: A quantitative model of visual working memory confidence.

    Science.gov (United States)

    van den Berg, Ronald; Yoo, Aspen H; Ma, Wei Ji

    2017-03-01

    Although visual working memory (VWM) has been studied extensively, it is unknown how people form confidence judgments about their memories. Peirce (1878) speculated that Fechner's law-which states that sensation is proportional to the logarithm of stimulus intensity-might apply to confidence reports. Based on this idea, we hypothesize that humans map the precision of their VWM contents to a confidence rating through Fechner's law. We incorporate this hypothesis into the best available model of VWM encoding and fit it to data from a delayed-estimation experiment. The model provides an excellent account of human confidence rating distributions as well as the relation between performance and confidence. Moreover, the best-fitting mapping in a model with a highly flexible mapping closely resembles the logarithmic mapping, suggesting that no alternative mapping exists that accounts better for the data than Fechner's law. We propose a neural implementation of the model and find that this model also fits the behavioral data well. Furthermore, we find that jointly fitting memory errors and confidence ratings boosts the power to distinguish previously proposed VWM encoding models by a factor of 5.99 compared to fitting only memory errors. Finally, we show that Fechner's law also accounts for metacognitive judgments in a word recognition memory task, which is a first indication that it may be a general law in metacognition. Our work presents the first model to jointly account for errors and confidence ratings in VWM and could lay the groundwork for understanding the computational mechanisms of metacognition. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Final Report: Phase II Nevada Water Resources Data, Modeling, and Visualization (DMV) Center

    Energy Technology Data Exchange (ETDEWEB)

    Jackman, Thomas [Desert Research Institute; Minor, Timothy [Desert Research Institute; Pohll, Gregory [Desert Research Institute

    2013-07-22

    Water is unquestionably a critical resource throughout the United States. In the semi-arid west -- an area stressed by increase in human population and sprawl of the built environment -- water is the most important limiting resource. Crucially, science must understand factors that affect availability and distribution of water. To sustain growing consumptive demand, science needs to translate understanding into reliable and robust predictions of availability under weather conditions that could be average but might be extreme. These predictions are needed to support current and long-term planning. Similar to the role of weather forecast and climate prediction, water prediction over short and long temporal scales can contribute to resource strategy, governmental policy and municipal infrastructure decisions, which are arguably tied to the natural variability and unnatural change to climate. Change in seasonal and annual temperature, precipitation, snowmelt, and runoff affect the distribution of water over large temporal and spatial scales, which impact the risk of flooding and the groundwater recharge. Anthropogenic influences and impacts increase the complexity and urgency of the challenge. The goal of this project has been to develop a decision support framework of data acquisition, digital modeling, and 3D visualization. This integrated framework consists of tools for compiling, discovering and projecting our understanding of processes that control the availability and distribution of water. The framework is intended to support the analysis of the complex interactions between processes that affect water supply, from controlled availability to either scarcity or deluge. The developed framework enables DRI to promote excellence in water resource management, particularly within the Lake Tahoe basin. In principle, this framework could be replicated for other watersheds throughout the United States. Phase II of this project builds upon the research conducted during

  20. Modeling multiple visual words assignment for bag-of-features based medical image retrieval

    KAUST Repository

    Wang, Jim Jing-Yan

    2012-01-01

    In this paper, we investigate the bag-of-features based medical image retrieval methods, which represent an image as a collection of local features, such as image patch and key points with SIFT descriptor. To improve the bag-of-features method, we first model the assignment of local descriptor as contribution functions, and then propose a new multiple assignment strategy. By assuming the local feature can be reconstructed by its neighboring visual words in vocabulary, we solve the reconstruction weights as a QP problem and then use the solved weights as contribution functions, which results in a new assignment method called the QP assignment. We carry our experiments on ImageCLEFmed datasets. Experiments\\' results show that our proposed method exceeds the performances of traditional solutions and works well for the bag-of-features based medical image retrieval tasks.

  1. A tone mapping operator based on neural and psychophysical models of visual perception

    Science.gov (United States)

    Cyriac, Praveen; Bertalmio, Marcelo; Kane, David; Vazquez-Corral, Javier

    2015-03-01

    High dynamic range imaging techniques involve capturing and storing real world radiance values that span many orders of magnitude. However, common display devices can usually reproduce intensity ranges only up to two to three orders of magnitude. Therefore, in order to display a high dynamic range image on a low dynamic range screen, the dynamic range of the image needs to be compressed without losing details or introducing artefacts, and this process is called tone mapping. A good tone mapping operator must be able to produce a low dynamic range image that matches as much as possible the perception of the real world scene. We propose a two stage tone mapping approach, in which the first stage is a global method for range compression based on a gamma curve that equalizes the lightness histogram the best, and the second stage performs local contrast enhancement and color induction using neural activity models for the visual cortex.

  2. 3D model of the Bernese Part of the Swiss Molasse Basin: visualization of uncertainties in a 3D model

    Science.gov (United States)

    Mock, Samuel; Allenbach, Robin; Reynolds, Lance; Wehrens, Philip; Kurmann-Matzenauer, Eva; Kuhn, Pascal; Michael, Salomè; Di Tommaso, Gennaro; Herwegh, Marco

    2016-04-01

    The Swiss Molasse Basin comprises the western and central part of the North Alpine Foreland Basin. In recent years it has come under closer scrutiny due to its promising geopotentials such as geothermal energy and CO2 sequestration. In order to adress these topics good knowledge of the subsurface is a key prerequisite. For that matter, geological 3D models serve as valuable tools. In collaboration with the Swiss Geological Survey (swisstopo) and as part of the project GeoMol CH, a geological 3D model of the Swiss Molasse Basin in the Canton of Bern has been built. The model covers an area of 1810 km2and reaches depth of up to 6.7 km. It comprises 10 major Cenozoic and Mesozoic units and numerous faults. The 3D model is mainly based on 2D seismic data complemented by information from few deep wells. Additionally, data from geological maps and profiles were used for refinement at shallow depths. In total, 1163 km of reflection seismic data, along 77 seismic lines, have been interpreted by different authors with respect to stratigraphy and structures. Both, horizons and faults, have been interpreted in 2D and modelled in 3D using IHS's Kingdom Suite and Midland Valley's MOVE software packages, respectively. Given the variable degree of subsurface information available, each 3D model is subject of uncertainty. With the primary input data coming from interpretation of reflection seismic data, a variety of uncertainties comes into play. Some of them are difficult to address (e.g. author's style of interpretation) while others can be quantified (e.g. mis-tie correction, well-tie). An important source of uncertainties is the quality of seismic data; this affects the traceability and lateral continuation of seismic reflectors. By defining quality classes we can semi-quantify this source of uncertainty. In order to visualize the quality and density of the input data in a meaningful way, we introduce quality-weighted data density maps. In combination with the geological 3D

  3. Visible Earthquakes: a web-based tool for visualizing and modeling InSAR earthquake data

    Science.gov (United States)

    Funning, G. J.; Cockett, R.

    2012-12-01

    InSAR (Interferometric Synthetic Aperture Radar) is a technique for measuring the deformation of the ground using satellite radar data. One of the principal applications of this method is in the study of earthquakes; in the past 20 years over 70 earthquakes have been studied in this way, and forthcoming satellite missions promise to enable the routine and timely study of events in the future. Despite the utility of the technique and its widespread adoption by the research community, InSAR does not feature in the teaching curricula of most university geoscience departments. This is, we believe, due to a lack of accessibility to software and data. Existing tools for the visualization and modeling of interferograms are often research-oriented, command line-based and/or prohibitively expensive. Here we present a new web-based interactive tool for comparing real InSAR data with simple elastic models. The overall design of this tool was focused on ease of access and use. This tool should allow interested nonspecialists to gain a feel for the use of such data and greatly facilitate integration of InSAR into upper division geoscience courses, giving students practice in comparing actual data to modeled results. The tool, provisionally named 'Visible Earthquakes', uses web-based technologies to instantly render the displacement field that would be observable using InSAR for a given fault location, geometry, orientation, and slip. The user can adjust these 'source parameters' using a simple, clickable interface, and see how these affect the resulting model interferogram. By visually matching the model interferogram to a real earthquake interferogram (processed separately and included in the web tool) a user can produce their own estimates of the earthquake's source parameters. Once satisfied with the fit of their models, users can submit their results and see how they compare with the distribution of all other contributed earthquake models, as well as the mean and median

  4. 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.

  5. A rabbit model of atherosclerosis at carotid artery: MRI visualization and histopathological characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhan-Long; Teng, Gao-Jun; Chen, Jun; Zhang, Hong-Ying; Cao, Ai-Hong [Zhong-Da Hospital, Southeast University, Molecular Imaging Laboratory, Department of Radiology, Nanjing (China); Ni, Yicheng [University Hospitals, Catholic University of Leuven, Department of Radiology, Leuven (Belgium)

    2008-10-15

    To induce a rabbit model of atherosclerosis at carotid artery, to visualize the lesion evolution with magnetic resonance imaging (MRI), and to characterize the lesion types by histopathology. Atherosclerosis at the right common carotid artery (RCCA) was induced in 23 rabbits by high-lipid diet following balloon catheter injury to the endothelium. The rabbits were examined in vivo with a 1.5-T MRI and randomly divided into three groups of 6 weeks (n=6), 12 weeks (n=8) and 15 weeks (n=9) for postmortem histopathology. The lesions on both MRI and histology were categorized according to the American Heart Association (AHA) classifications of atherosclerosis. Type I and type II of atherosclerotic changes were detected at week 6, i.e., nearly normal signal intensity (SI) of the injured RCCA wall without stenosis on MRI, but with subendothelial inflammatory infiltration and proliferation of smooth muscle cells on histopathology. At week 12, 75.0% and 62.5% of type III changes were encountered on MRI and histopathology respectively with thicker injured RCCA wall of increased SI on T{sub 1}-weighted and proton density (PD)-weighted MRI and microscopically a higher degree of plaque formation. At week 15, carotid atherosclerosis became more advanced, i.e., type IV and type V in 55.6% and 22.2% of the lesions with MRI and 55.6% and 33.3% of the lesions with histopathology, respectively. Statistical analysis revealed a significant agreement (p<0.05) between the MRI and histological findings for lesion classification (r=0.96). A rabbit model of carotid artery atherosclerosis has been successfully induced and noninvasively visualized. The atherosclerotic plaque formation evolved from type I to type V with time, which could be monitored with 1.5-T MRI and confirmed with histomorphology. This experimental setting can be applied in preclinical research on atherosclerosis. (orig.)

  6. Forward Models Applied in Visual Servoing for a Reaching Task in the iCub Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Daniel Fernando Tello Gamarra

    2009-01-01

    Full Text Available This paper details the application of a forward model to improve a reaching task. The reaching task must be accomplished by a humanoid robot with 53 degrees of freedom (d.o.f. and a stereo-vision system. We have explored via simulations a new way of constructing and utilizing a forward model that encodes eye–hand relationships. We constructed a forward model using the data obtained from only a single reaching attempt. ANFIS neural networks are used to construct the forward model, but the forward model is updated online with new information that comes from each reaching attempt. Using the obtained forward model, an initial image Jacobian is estimated and is used with a visual servoing controller. Simulation results demonstrate that errors are lower when the initial image Jacobian is derived from the forward model. This paper is one of the few attempts at applying visual servoing in a complete humanoid robot.

  7. Investigations into the low temperature behavior of jet fuels: Visualization, modeling, and viscosity studies

    Science.gov (United States)

    Atkins, Daniel L.

    Aircraft operation in arctic regions or at high altitudes exposes jet fuel to temperatures below freeze point temperature specifications. Fuel constituents may solidify and remain within tanks or block fuel system components. Military and scientific requirements have been met with costly, low freeze point specialty jet fuels. Commercial airline interest in polar routes and the use of high altitude unmanned aerial vehicles (UAVs) has spurred interest in the effects of low temperatures and low-temperature additives on jet fuel. The solidification of jet fuel due to freezing is not well understood and limited visualization of fuel freezing existed prior to the research presented in this dissertation. Consequently, computational fluid dynamics (CFD) modeling that simulates jet fuel freezing and model validation were incomplete prior to the present work. The ability to simulate jet fuel freezing is a necessary tool for fuel system designers. An additional impediment to the understanding and simulation of jet fuel freezing has been the absence of published low-temperature thermo-physical properties, including viscosity, which the present work addresses. The dissertation is subdivided into three major segments covering visualization, modeling and validation, and viscosity studies. In the first segment samples of jet fuel, JPTS, kerosene, Jet A and Jet A containing additives, were cooled below their freeze point temperatures in a rectangular, optical cell. Images and temperature data recorded during the solidification process provided information on crystal habit, crystallization behavior, and the influence of the buoyancy-driven flow on freezing. N-alkane composition of the samples was determined. The Jet A sample contained the least n-alkane mass. The cooling of JPTS resulted in the least wax formation while the cooling of kerosene yielded the greatest wax formation. The JPTS and kerosene samples exhibited similar crystallization behavior and crystal habits during

  8. VESL: The Virtual Earth Sheet Laboratory for Ice Sheet Modeling and Visualization

    Science.gov (United States)

    Cheng, D. L. C.; Larour, E. Y.; Quinn, J. D.; Halkides, D. J.

    2016-12-01

    We introduce the Virtual Earth System Laboratory (VESL), a scientific modeling and visualization tool delivered through an integrated web portal for dissemination of data, simulation of physical processes, and promotion of climate literacy. The current prototype leverages NASA's Ice Sheet System Model (ISSM), a state-of-the-art polar ice sheet dynamics model developed at the Jet Propulsion Lab and UC Irvine. We utilize the Emscripten source-to-source compiler to convert the C/C++ ISSM engine core to JavaScript, and bundled pre/post-processing JS scripts to be compatible with the existing ISSM Python/Matlab API. Researchers using VESL will be able to effectively present their work for public dissemination with little-to-no additional post-processing. This will allow for faster publication in peer-reviewed journals and adaption of results for educational applications. Through future application of this concept to multiple aspects of the Earth System, VESL has the potential to broaden data applications in the geosciences and beyond. At this stage, we seek feedback from the greater scientific and public outreach communities regarding the ease of use and feature set of VESL, as we plan its expansion, and aim to achieve more rapid communication and presentation of scientific results.

  9. ChromaStarPy: A Stellar Atmosphere and Spectrum Modeling and Visualization Lab in Python

    Science.gov (United States)

    Short, C. Ian; Bayer, Jason H. T.; Burns, Lindsey M.

    2018-02-01

    We announce ChromaStarPy, an integrated general stellar atmospheric modeling and spectrum synthesis code written entirely in python V. 3. ChromaStarPy is a direct port of the ChromaStarServer (CSServ) Java modeling code described in earlier papers in this series, and many of the associated JavaScript (JS) post-processing procedures have been ported and incorporated into CSPy so that students have access to ready-made data products. A python integrated development environment (IDE) allows a student in a more advanced course to experiment with the code and to graphically visualize intermediate and final results, ad hoc, as they are running it. CSPy allows students and researchers to compare modeled to observed spectra in the same IDE in which they are processing observational data, while having complete control over the stellar parameters affecting the synthetic spectra. We also take the opportunity to describe improvements that have been made to the related codes, ChromaStar (CS), CSServ, and ChromaStarDB (CSDB), that, where relevant, have also been incorporated into CSPy. The application may be found at the home page of the OpenStars project: http://www.ap.smu.ca/OpenStars/.

  10. TRACX2: a connectionist autoencoder using graded chunks to model infant visual statistical learning.

    Science.gov (United States)

    Mareschal, Denis; French, Robert M

    2017-01-05

    Even newborn infants are able to extract structure from a stream of sensory inputs; yet how this is achieved remains largely a mystery. We present a connectionist autoencoder model, TRACX2, that learns to extract sequence structure by gradually constructing chunks, storing these chunks in a distributed manner across its synaptic weights and recognizing these chunks when they re-occur in the input stream. Chunks are graded rather than all-or-nothing in nature. As chunks are learnt their component parts become more and more tightly bound together. TRACX2 successfully models the data from five experiments from the infant visual statistical learning literature, including tasks involving forward and backward transitional probabilities, low-salience embedded chunk items, part-sequences and illusory items. The model also captures performance differences across ages through the tuning of a single-learning rate parameter. These results suggest that infant statistical learning is underpinned by the same domain-general learning mechanism that operates in auditory statistical learning and, potentially, in adult artificial grammar learning.This article is part of the themed issue 'New frontiers for statistical learning in the cognitive sciences'. © 2016 The Author(s).

  11. How information visualization novices construct visualizations.

    Science.gov (United States)

    Grammel, Lars; Tory, Melanie; Storey, Margaret-Anne

    2010-01-01

    It remains challenging for information visualization novices to rapidly construct visualizations during exploratory data analysis. We conducted an exploratory laboratory study in which information visualization novices explored fictitious sales data by communicating visualization specifications to a human mediator, who rapidly constructed the visualizations using commercial visualization software. We found that three activities were central to the iterative visualization construction process: data attribute selection, visual template selection, and visual mapping specification. The major barriers faced by the participants were translating questions into data attributes, designing visual mappings, and interpreting the visualizations. Partial specification was common, and the participants used simple heuristics and preferred visualizations they were already familiar with, such as bar, line and pie charts. We derived abstract models from our observations that describe barriers in the data exploration process and uncovered how information visualization novices think about visualization specifications. Our findings support the need for tools that suggest potential visualizations and support iterative refinement, that provide explanations and help with learning, and that are tightly integrated into tool support for the overall visual analytics process.

  12. Tests of a linear model of visual-vestibular interaction using the technique of parameter estimation.

    Science.gov (United States)

    Das, V E; DiScenna, A O; Feltz, A; Yaniglos, S; Leigh, R J

    1998-03-01

    The goal of this study was to test whether a superposition model of smooth-pursuit and vestibuloocular reflex (VOR) eye movements could account for the stability of gaze that subjects show as they view a stationary target, during head rotations at frequencies that correspond to natural movements. Horizontal smooth-pursuit and the VOR were tested using sinusoidal stimuli with frequencies in the range 1.0-3.5 Hz. During head rotation, subjects viewed a stationary target either directly or through an optical device that required eye movements to be approximately twice the amplitude of head movements in order to maintain foveal vision of the target. The gain of compensatory eye movements during viewing through the optical device was generally greater than during direct viewing or during attempted fixation of the remembered target location in darkness. This suggests that visual factors influence the response, even at high frequencies of head rotation. During viewing through the optical device, the gain of compensatory eye movements declined as a function of the frequency of head rotation (P 0.23), peak head acceleration (P > 0.22) or retinal slip speed (P > 0.22). The optimal values of parameters of smooth-pursuit and VOR components of a simple superposition model were estimated in the frequency domain, using the measured responses during head rotation, as each subject viewed the stationary target through the optical device. We then compared the model's prediction of smooth-pursuit gain and phase, at each frequency, with values obtained experimentally. Each subject's pursuit showed lower gain and greater phase lag than the model predicted. Smooth-pursuit performance did not improve significantly if the moving target was a 10 deg x 10 deg Amsler grid, or if sinusoidal oscillation of the target was superimposed on ramp motion. Further, subjects were still able to modulate the gain of compensatory eye movements during pseudo-random head perturbations, making improved

  13. Flow Visualization of a Scramjet Inlet - Isolator Model in Supersonic Flow

    Science.gov (United States)

    Seckin, S.; Yuceil, K. B.

    2013-04-01

    Understanding the physical mechanisms and having insight to the complex flowfield involving unstart phenomena in supersonic inlets has gained considerable attention especially in the area of scramjet inlet/isolator aerothermodynamics. In this study, Schlieren visualization and computational analysis of shock wave structures in ramjet/scramjet inlet/isolator models in supersonic flow have been performed. Experiments were performed in the supersonic wind tunnel at the Trisonic Research Laboratory in Istanbul Technical University. The test section floor and the existing mechanism underneath have been modified to be able to mount the designed inlet/isolator model on the floor of the test section. The inlet/isolator model with a 12- degree compression ramp is investigated at Mach 2 both computationally and experimentally. Computations were performed using Star-CCM+ software to investigate shock wave structures in and around the three dimensional inlet/isolator model as mounted on the test section floor as a guide for designing the experimental model. In the results, the effects of shock wave - boundary layer interactions with flow separations with were observed. Ensemble average of the density distributions on a series of planes from one side wall to the other from the CFD results agreed well with the Schlieren images obtained experimentally. The structure of the shock waves and angles obtained from the Schlieren images agree quite well with those obtained from the CFD results. The effects of lambda-shock formations which indicate possible boundary layer separations, reflections of shock waves, and shock wave - boundary layer interactions on inlet unstart phenomena have been discussed. In order to investigate inlet unstart mechanism further, different experimental setups have been suggested for future work.

  14. Flow Visualization of a Scramjet Inlet – Isolator Model in Supersonic Flow

    Directory of Open Access Journals (Sweden)

    Yuceil K.B.

    2013-04-01

    Full Text Available Understanding the physical mechanisms and having insight to the complex flowfield involving unstart phenomena in supersonic inlets has gained considerable attention especially in the area of scramjet inlet/isolator aerothermodynamics. In this study, Schlieren visualization and computational analysis of shock wave structures in ramjet/scramjet inlet/isolator models in supersonic flow have been performed. Experiments were performed in the supersonic wind tunnel at the Trisonic Research Laboratory in Istanbul Technical University. The test section floor and the existing mechanism underneath have been modified to be able to mount the designed inlet/isolator model on the floor of the test section. The inlet/isolator model with a 12- degree compression ramp is investigated at Mach 2 both computationally and experimentally. Computations were performed using Star-CCM+ software to investigate shock wave structures in and around the three dimensional inlet/isolator model as mounted on the test section floor as a guide for designing the experimental model. In the results, the effects of shock wave – boundary layer interactions with flow separations with were observed. Ensemble average of the density distributions on a series of planes from one side wall to the other from the CFD results agreed well with the Schlieren images obtained experimentally. The structure of the shock waves and angles obtained from the Schlieren images agree quite well with those obtained from the CFD results. The effects of lambda-shock formations which indicate possible boundary layer separations, reflections of shock waves, and shock wave – boundary layer interactions on inlet unstart phenomena have been discussed. In order to investigate inlet unstart mechanism further, different experimental setups have been suggested for future work.

  15. A Closed-Loop Model of Operator Visual Attention, Situation Awareness, and Performance Across Automation Mode Transitions.

    Science.gov (United States)

    Johnson, Aaron W; Duda, Kevin R; Sheridan, Thomas B; Oman, Charles M

    2017-03-01

    This article describes a closed-loop, integrated human-vehicle model designed to help understand the underlying cognitive processes that influenced changes in subject visual attention, mental workload, and situation awareness across control mode transitions in a simulated human-in-the-loop lunar landing experiment. Control mode transitions from autopilot to manual flight may cause total attentional demands to exceed operator capacity. Attentional resources must be reallocated and reprioritized, which can increase the average uncertainty in the operator's estimates of low-priority system states. We define this increase in uncertainty as a reduction in situation awareness. We present a model built upon the optimal control model for state estimation, the crossover model for manual control, and the SEEV (salience, effort, expectancy, value) model for visual attention. We modify the SEEV attention executive to direct visual attention based, in part, on the uncertainty in the operator's estimates of system states. The model was validated using the simulated lunar landing experimental data, demonstrating an average difference in the percentage of attention ≤3.6% for all simulator instruments. The model's predictions of mental workload and situation awareness, measured by task performance and system state uncertainty, also mimicked the experimental data. Our model supports the hypothesis that visual attention is influenced by the uncertainty in system state estimates. Conceptualizing situation awareness around the metric of system state uncertainty is a valuable way for system designers to understand and predict how reallocations in the operator's visual attention during control mode transitions can produce reallocations in situation awareness of certain states.

  16. Experience-driven formation of parts-based representations in a model of layered visual memory

    Directory of Open Access Journals (Sweden)

    Jenia Jitsev

    2009-09-01

    Full Text Available Growing neuropsychological and neurophysiological evidence suggests that the visual cortex uses parts-based representations to encode, store and retrieve relevant objects. In such a scheme, objects are represented as a set of spatially distributed local features, or parts, arranged in stereotypical fashion. To encode the local appearance and to represent the relations between the constituent parts, there has to be an appropriate memory structure formed by previous experience with visual objects. Here, we propose a model how a hierarchical memory structure supporting efficient storage and rapid recall of parts-based representations can be established by an experience-driven process of self-organization. The process is based on the collaboration of slow bidirectional synaptic plasticity and homeostatic unit activity regulation, both running at the top of fast activity dynamics with winner-take-all character modulated by an oscillatory rhythm. These neural mechanisms lay down the basis for cooperation and competition between the distributed units and their synaptic connections. Choosing human face recognition as a test task, we show that, under the condition of open-ended, unsupervised incremental learning, the system is able to form memory traces for individual faces in a parts-based fashion. On a lower memory layer the synaptic structure is developed to represent local facial features and their interrelations, while the identities of different persons are captured explicitly on a higher layer. An additional property of the resulting representations is the sparseness of both the activity during the recall and the synaptic patterns comprising the memory traces.

  17. Deep learning-based fine-grained car make/model classification for visual surveillance

    Science.gov (United States)

    Gundogdu, Erhan; Parıldı, Enes Sinan; Solmaz, Berkan; Yücesoy, Veysel; Koç, Aykut

    2017-10-01

    Fine-grained object recognition is a potential computer vision problem that has been recently addressed by utilizing deep Convolutional Neural Networks (CNNs). Nevertheless, the main disadvantage of classification methods relying on deep CNN models is the need for considerably large amount of data. In addition, there exists relatively less amount of annotated data for a real world application, such as the recognition of car models in a traffic surveillance system. To this end, we mainly concentrate on the classification of fine-grained car make and/or models for visual scenarios by the help of two different domains. First, a large-scale dataset including approximately 900K images is constructed from a website which includes fine-grained car models. According to their labels, a state-of-the-art CNN model is trained on the constructed dataset. The second domain that is dealt with is the set of images collected from a camera integrated to a traffic surveillance system. These images, which are over 260K, are gathered by a special license plate detection method on top of a motion detection algorithm. An appropriately selected size of the image is cropped from the region of interest provided by the detected license plate location. These sets of images and their provided labels for more than 30 classes are employed to fine-tune the CNN model which is already trained on the large scale dataset described above. To fine-tune the network, the last two fully-connected layers are randomly initialized and the remaining layers are fine-tuned in the second dataset. In this work, the transfer of a learned model on a large dataset to a smaller one has been successfully performed by utilizing both the limited annotated data of the traffic field and a large scale dataset with available annotations. Our experimental results both in the validation dataset and the real field show that the proposed methodology performs favorably against the training of the CNN model from scratch.

  18. Comparison of L-system applications towards plant modelling, music rendering and score generation using visual language programming

    Science.gov (United States)

    Lim, Chen Kim; Tan, Kian Lam; Yusran, Hazwanni; Suppramaniam, Vicknesh

    2017-10-01

    Visual language or visual representation has been used in the past few years in order to express the knowledge in graphic. One of the important graphical elements is fractal and L-Systems is a mathematic-based grammatical model for modelling cell development and plant topology. From the plant model, L-Systems can be interpreted as music sound and score. In this paper, LSound which is a Visual Language Programming (VLP) framework has been developed to model plant to music sound and generate music score and vice versa. The objectives of this research has three folds: (i) To expand the grammar dictionary of L-Systems music based on visual programming, (ii) To design and produce a user-friendly and icon based visual language framework typically for L-Systems musical score generation which helps the basic learners in musical field and (iii) To generate music score from plant models and vice versa using L-Systems method. This research undergoes a four phases methodology where the plant is first modelled, then the music is interpreted, followed by the output of music sound through MIDI and finally score is generated. LSound is technically compared to other existing applications in the aspects of the capability of modelling the plant, rendering the music and generating the sound. It has been found that LSound is a flexible framework in which the plant can be easily altered through arrow-based programming and the music score can be altered through the music symbols and notes. This work encourages non-experts to understand L-Systems and music hand-in-hand.

  19. Towards a unified model of face and object recognition in the human visual system

    Directory of Open Access Journals (Sweden)

    Guy eWallis

    2013-08-01

    Full Text Available Our understanding of the mechanisms and neural substrates underlying visual recognition in humans has made considerable progress over the past thirty years. During this period a divide has developed between the fields of object and face recognition. In the psychological literature, in particular, there has been a palpable disconnect between the two fields. This paper follows a trend in part of the face-recognition literature to try to reconcile what we know about these two forms of recognition by considering the effects of learning. Taking a widely accepted, self-organizing model of object recognition, this paper explains how such a system is affected by repeated exposure to specific stimulus classes. In so doing, it explains how many aspects of recognition generally regarded as unusual to faces (holistic processing, configural processing, sensitivity to inversion, the other race effect, the prototype effect, etc. are emergent properties of category-specific learning within such a system. Overall, the paper describes how a single model of recognition learning can and does produce the two, apparently very different types of stimulus representation associated with faces and objects.

  20. Animal models of retinal detachment and reattachment: identifying cellular events that may affect visual recovery.

    Science.gov (United States)

    Lewis, G P; Charteris, D G; Sethi, C S; Fisher, S K

    2002-07-01

    Retinal detachment continues to be a significant cause of visual impairment, either through the direct effects of macular detachment or through secondary complications such as subretinal fibrosis or proliferative vitreoretinopathy. Animal models can provide us with an understanding of the cellular mechanisms at work that account for the retinopathy induced by detachment and for the generation of secondary effects. As we understand the mechanisms involved, animal models can also provide us with opportunities to test therapeutic agents that may reduce the damaging effects of detachment or improve the outcome of reattachment surgery. They may also reveal information of use to understanding other causes of blindness rooted in retinal defects or injuries. Understanding the effects of detachment (and reattachment) are likely to become even more important as surgeons gain skills in subretinal surgical techniques and macular translocation, both of which will generate short-lived detachments. Here we discuss the fundamental events that occur after detachment, present changes associated with reattachment, and discuss retinal changes that may affect the return of vision.

  1. Synaptic augmentation in a cortical circuit model reproduces serial dependence in visual working memory.

    Science.gov (United States)

    Bliss, Daniel P; D'Esposito, Mark

    2017-01-01

    Recent work has established that visual working memory is subject to serial dependence: current information in memory blends with that from the recent past as a function of their similarity. This tuned temporal smoothing likely promotes the stability of memory in the face of noise and occlusion. Serial dependence accumulates over several seconds in memory and deteriorates with increased separation between trials. While this phenomenon has been extensively characterized in behavior, its neural mechanism is unknown. In the present study, we investigate the circuit-level origins of serial dependence in a biophysical model of cortex. We explore two distinct kinds of mechanisms: stable persistent activity during the memory delay period and dynamic "activity-silent" synaptic plasticity. We find that networks endowed with both strong reverberation to support persistent activity and dynamic synapses can closely reproduce behavioral serial dependence. Specifically, elevated activity drives synaptic augmentation, which biases activity on the subsequent trial, giving rise to a spatiotemporally tuned shift in the population response. Our hybrid neural model is a theoretical advance beyond abstract mathematical characterizations, offers testable hypotheses for physiological research, and demonstrates the power of biological insights to provide a quantitative explanation of human behavior.

  2. Electromagnetic Computation and Visualization of Transmission Particle Model and Its Simulation Based on GPU

    Directory of Open Access Journals (Sweden)

    Yingnian Wu

    2014-01-01

    Full Text Available Electromagnetic calculation plays an important role in both military and civic fields. Some methods and models proposed for calculation of electromagnetic wave propagation in a large range bring heavy burden in CPU computation and also require huge amount of memory. Using the GPU to accelerate computation and visualization can reduce the computational burden on the CPU. Based on forward ray-tracing method, a transmission particle model (TPM for calculating electromagnetic field is presented to combine the particle method. The movement of a particle obeys the principle of the propagation of electromagnetic wave, and then the particle distribution density in space reflects the electromagnetic distribution status. The algorithm with particle transmission, movement, reflection, and diffraction is described in detail. Since the particles in TPM are completely independent, it is very suitable for the parallel computing based on GPU. Deduction verification of TPM with the electric dipole antenna as the transmission source is conducted to prove that the particle movement itself represents the variation of electromagnetic field intensity caused by diffusion. Finally, the simulation comparisons are made against the forward and backward ray-tracing methods. The simulation results verified the effectiveness of the proposed method.

  3. Observed trends in aerosol optical properties, visualization and comparison to models

    Science.gov (United States)

    Schulz, Michael; Mortier, Augustin; Andrews, Betsy; Myhre, Cathrine Lund; Collaud-Coen, Martine; Griesfeller, Jan

    2017-04-01

    Several long term data sets are developed and documented recently in ACTRIS, cci-aerosol, GAW and AeroCom, which can serve to update our knowledge on trends in optical aerosol parameters. Regional trends in aerosol optical parameters, which signal significant changes in emissions, are most relevant to understand aerosol radiative forcing. Here we aim to explore measurements of in-situ scattering and absorption (ACTRIS/GAW) together with aerosol optical thickness from satellites (cci-Aerosol) and sun photometer networks (Aeronet). Modelled trends are available from the AeroCom model data comparison initiative. Multi-annual data of all these data sources are visualized via the trend web interface, developed at MetNo. Trends and their significance level are computed and shown for all seasons and yearly averages. We present preliminary findings and discuss how the results can be transformed into products of use to the scientific user community. We acknowledge most valuable cooperation within ACTRIS, Aeronet, GAW and AeroCom.

  4. Models of deletion for visualizing bacterial variation: an application to tuberculosis spoligotypes

    Directory of Open Access Journals (Sweden)

    Francis Andrew R

    2008-11-01

    Full Text Available Abstract Background Molecular typing methods are commonly used to study genetic relationships among bacterial isolates. Many of these methods have become standardized and produce portable data. A popular approach for analyzing such data is to construct graphs, including phylogenies. Inferences from graph representations of data assist in understanding the patterns of transmission of bacterial pathogens, and basing these graph constructs on biological models of evolution of the molecular marker helps make these inferences. Spoligotyping is a widely used method for genotyping isolates of Mycobacterium tuberculosis that exploits polymorphism in the direct repeat region. Our goal was to examine a range of models describing the evolution of spoligotypes in order to develop a visualization method to represent likely relationships among M. tuberculosis isolates. Results We found that inferred mutations of spoligotypes frequently involve the loss of a single or very few adjacent spacers. Using a second-order variant of Akaike's Information Criterion, we selected the Zipf model as the basis for resolving ambiguities in the ancestry of spoligotypes. We developed a method to construct graphs of spoligotypes (which we call spoligoforests. To demonstrate this method, we applied it to a tuberculosis data set from Cuba and compared the method to some existing methods. Conclusion We propose a new approach in analyzing relationships of M. tuberculosis isolates using spoligotypes. The spoligoforest recovers a plausible history of transmission and mutation events based on the selected deletion model. The method may be suitable to study markers based on loci of similar structure from other bacteria. The groupings and relationships in the spoligoforest can be analyzed along with the clinical features of strains to provide an understanding of the evolution of spoligotypes.

  5. The role of visual and spatial working memory in forming mental models derived from survey and route descriptions.

    Science.gov (United States)

    Meneghetti, Chiara; Labate, Enia; Pazzaglia, Francesca; Hamilton, Colin; Gyselinck, Valérie

    2017-05-01

    This study examines the involvement of spatial and visual working memory (WM) in the construction of flexible spatial models derived from survey and route descriptions. Sixty young adults listened to environment descriptions, 30 from a survey perspective and the other 30 from a route perspective, while they performed spatial (spatial tapping [ST]) and visual (dynamic visual noise [DVN]) secondary tasks - believed to overload the spatial and visual working memory (WM) components, respectively - or no secondary task (control, C). Their mental representations of the environment were tested by free recall and a verification test with both route and survey statements. Results showed that, for both recall tasks, accuracy was worse in the ST than in the C or DVN conditions. In the verification test, the effect of both ST and DVN was a decreasing accuracy for sentences testing spatial relations from the opposite perspective to the one learnt than if the perspective was the same; only ST had a stronger interference effect than the C condition for sentences from the opposite perspective from the one learnt. Overall, these findings indicate that both visual and spatial WM, and especially the latter, are involved in the construction of perspective-flexible spatial models. © 2016 The British Psychological Society.

  6. Automatic Tuning of a Retina Model for a Cortical Visual Neuroprosthesis Using a Multi-Objective Optimization Genetic Algorithm.

    Science.gov (United States)

    Martínez-Álvarez, Antonio; Crespo-Cano, Rubén; Díaz-Tahoces, Ariadna; Cuenca-Asensi, Sergio; Ferrández Vicente, José Manuel; Fernández, Eduardo

    2016-11-01

    The retina is a very complex neural structure, which contains many different types of neurons interconnected with great precision, enabling sophisticated conditioning and coding of the visual information before it is passed via the optic nerve to higher visual centers. The encoding of visual information is one of the basic questions in visual and computational neuroscience and is also of seminal importance in the field of visual prostheses. In this framework, it is essential to have artificial retina systems to be able to function in a way as similar as possible to the biological retinas. This paper proposes an automatic evolutionary multi-objective strategy based on the NSGA-II algorithm for tuning retina models. Four metrics were adopted for guiding the algorithm in the search of those parameters that best approximate a synthetic retinal model output with real electrophysiological recordings. Results show that this procedure exhibits a high flexibility when different trade-offs has to be considered during the design of customized neuro prostheses.

  7. Visualizing water

    Science.gov (United States)

    Baart, F.; van Gils, A.; Hagenaars, G.; Donchyts, G.; Eisemann, E.; van Velzen, J. W.

    2016-12-01

    A compelling visualization is captivating, beautiful and narrative. Here we show how melding the skills of computer graphics, art, statistics, and environmental modeling can be used to generate innovative, attractive and very informative visualizations. We focus on the topic of visualizing forecasts and measurements of water (water level, waves, currents, density, and salinity). For the field of computer graphics and arts, water is an important topic because it occurs in many natural scenes. For environmental modeling and statistics, water is an important topic because the water is essential for transport, a healthy environment, fruitful agriculture, and a safe environment.The different disciplines take different approaches to visualizing water. In computer graphics, one focusses on creating water as realistic looking as possible. The focus on realistic perception (versus the focus on the physical balance pursued by environmental scientists) resulted in fascinating renderings, as seen in recent games and movies. Visualization techniques for statistical results have benefited from the advancement in design and journalism, resulting in enthralling infographics. The field of environmental modeling has absorbed advances in contemporary cartography as seen in the latest interactive data-driven maps. We systematically review the design emerging types of water visualizations. The examples that we analyze range from dynamically animated forecasts, interactive paintings, infographics, modern cartography to web-based photorealistic rendering. By characterizing the intended audience, the design choices, the scales (e.g. time, space), and the explorability we provide a set of guidelines and genres. The unique contributions of the different fields show how the innovations in the current state of the art of water visualization have benefited from inter-disciplinary collaborations.

  8. The influence of visual experience on the ability to form spatial mental models based on route and survey descriptions

    NARCIS (Netherlands)

    Noordzij, Matthijs Leendert; Zuidhoek, Sander; Postma, Albert

    2006-01-01

    The purpose of the present study is twofold: the first objective is to evaluate the importance of visual experience for the ability to form a spatial representation (spatial mental model) of fairly elaborate spatial descriptions. Secondly, we examine whether blind people exhibit the same preferences

  9. Qualitative Contrast between Knowledge-Limited Mixed-State and Variable-Resources Models of Visual Change Detection

    Science.gov (United States)

    Nosofsky, Robert M.; Donkin, Chris

    2016-01-01

    We report an experiment designed to provide a qualitative contrast between knowledge-limited versions of mixed-state and variable-resources (VR) models of visual change detection. The key data pattern is that observers often respond "same" on big-change trials, while simultaneously being able to discriminate between same and small-change…

  10. Visualizing multifactorial and multi-attribute effect sizes in linear mixed models with a view towards sensometrics

    DEFF Research Database (Denmark)

    In Brockhoff et al (2016), the close link between Cohen's d, the effect size in an ANOVA framework, and the so-called Thurstonian (Signal detection) d-prime was used to suggest better visualizations and interpretations of standard sensory and consumer data mixed model ANOVA results. The basic...... mechanisms inherently challenging effect size measure estimates in ANOVA settings....

  11. Modeling the approximate number system to quantify the contribution of visual stimulus features.

    Science.gov (United States)

    DeWind, Nicholas K; Adams, Geoffrey K; Platt, Michael L; Brannon, Elizabeth M

    2015-09-01

    The approximate number system (ANS) subserves estimation of the number of items in a set. Typically, ANS function is assessed by requiring participants to compare the number of dots in two arrays. Accuracy is determined by the numerical ratio of the sets being compared, and each participant's Weber fraction (w) provides a quantitative index of ANS acuity. When making numerical comparisons, however, performance is also influenced by non-numerical features of the stimuli, such as the size and spacing of dots. Current models of numerosity comparison do not account for these effects and consequently lead to different estimates of w depending on the methods used to control for non-numerical features. Here we proffer a new model that teases apart the effects of ANS acuity from the effects of non-numerical stimulus features. The result is an estimate of w that is a more theoretically valid representation of numerical acuity and novel terms that denote the degree to which a participant's perception of number is affected by non-numerical features. We tested this model in a sample of 20 adults and found that, by correctly attributing errors due to non-numerical stimulus features, the w obtained was more reliable across different stimulus conditions. We found that although non-numerical features biased numerosity discriminations in all participants, number was the primary feature driving discriminations in most of them. Our findings support the idea that, while numerosity is a distinct visual quantity, the internal representation of number is tightly bound to the representation of other magnitudes. This tool for identifying the different effects of the numerical and non-numerical features of a stimulus has important implications not only for the behavioral investigation of the ANS, but also for the collection and analyses of neural data sets associated with ANS function. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Geospatial Data Processing for 3d City Model Generation, Management and Visualization

    Science.gov (United States)

    Toschi, I.; Nocerino, E.; Remondino, F.; Revolti, A.; Soria, G.; Piffer, S.

    2017-05-01

    Recent developments of 3D technologies and tools have increased availability and relevance of 3D data (from 3D points to complete city models) in the geospatial and geo-information domains. Nevertheless, the potential of 3D data is still underexploited and mainly confined to visualization purposes. Therefore, the major challenge today is to create automatic procedures that make best use of available technologies and data for the benefits and needs of public administrations (PA) and national mapping agencies (NMA) involved in "smart city" applications. The paper aims to demonstrate a step forward in this process by presenting the results of the SENECA project (Smart and SustaiNablE City from Above - http://seneca.fbk.eu). State-of-the-art processing solutions are investigated in order to (i) efficiently exploit the photogrammetric workflow (aerial triangulation and dense image matching), (ii) derive topologically and geometrically accurate 3D geo-objects (i.e. building models) at various levels of detail and (iii) link geometries with non-spatial information within a 3D geo-database management system accessible via web-based client. The developed methodology is tested on two case studies, i.e. the cities of Trento (Italy) and Graz (Austria). Both spatial (i.e. nadir and oblique imagery) and non-spatial (i.e. cadastral information and building energy consumptions) data are collected and used as input for the project workflow, starting from 3D geometry capture and modelling in urban scenarios to geometry enrichment and management within a dedicated webGIS platform.

  13. Identification, control and visually-guided behavior for a model helicopter

    Science.gov (United States)

    Saripalli, Srikanth

    Research on unmanned aerial vehicles is motivated by applications where human intervention is impossible, risky or expensive e.g. hazardous material recovery, traffic monitoring, disaster relief support, military operations etc. Due to its vertical take-off, landing and hover capabilities, a helicopter is an attractive platform for such applications. There are significant challenges to building an autonomous robotic helicopter - these span the areas of system identification, low-level control, state estimation, and planning. Towards the goal of fully-autonomous helicopters this thesis makes the following contributions. A continuous-discrete extended Kalman filter has been developed that combines inertial data with GPS and compass data to provide estimates of the 6DOF state of the helicopter. Using this filter a model for the helicopter has been identified based on frequency response techniques. The model has been validated in flight tests on a small helicopter testbed (1.6 m rotor diameter) at speeds upto 5 m/s. Based on evidence from this model a decoupled low-level controller has been developed which is embedded in a control architecture suitable for visually-guided navigation. As a novel application, we show how such a controller can be used to perform trajectory following on the helicopter where the desired trajectories are typical spacecraft landing trajectories, and the only controls available are thrusters. This in effect, produces a low-cost testbed for testing spacecraft landing and hazard avoidance on a planetary surface. Finally, we develop and extensively experimentally characterize algorithms for vision-based autonomous landing, object tracking, and sensor deployment.

  14. GEOSPATIAL DATA PROCESSING FOR 3D CITY MODEL GENERATION, MANAGEMENT AND VISUALIZATION

    Directory of Open Access Journals (Sweden)

    I. Toschi

    2017-05-01

    Full Text Available Recent developments of 3D technologies and tools have increased availability and relevance of 3D data (from 3D points to complete city models in the geospatial and geo-information domains. Nevertheless, the potential of 3D data is still underexploited and mainly confined to visualization purposes. Therefore, the major challenge today is to create automatic procedures that make best use of available technologies and data for the benefits and needs of public administrations (PA and national mapping agencies (NMA involved in “smart city” applications. The paper aims to demonstrate a step forward in this process by presenting the results of the SENECA project (Smart and SustaiNablE City from Above – http://seneca.fbk.eu. State-of-the-art processing solutions are investigated in order to (i efficiently exploit the photogrammetric workflow (aerial triangulation and dense image matching, (ii derive topologically and geometrically accurate 3D geo-objects (i.e. building models at various levels of detail and (iii link geometries with non-spatial information within a 3D geo-database management system accessible via web-based client. The developed methodology is tested on two case studies, i.e. the cities of Trento (Italy and Graz (Austria. Both spatial (i.e. nadir and oblique imagery and non-spatial (i.e. cadastral information and building energy consumptions data are collected and used as input for the project workflow, starting from 3D geometry capture and modelling in urban scenarios to geometry enrichment and management within a dedicated webGIS platform.

  15. Visual Trajectory-Tracking Model-Based Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    Andrej Zdešar

    2013-09-01

    Full Text Available In this paper we present a visual-control algorithm for driving a mobile robot along the reference trajectory. The configuration of the system consists of a two-wheeled differentially driven mobile robot that is observed by an overhead camera, which can be placed at arbitrary, but reasonable, inclination with respect to the ground plane. The controller must be capable of generating appropriate tangential and angular control velocities for the trajectory-tracking problem, based on the information received about the robot position obtained in the image. To be able to track the position of the robot through a sequence of images in real-time, the robot is marked with an artificial marker that can be distinguishably recognized by the image recognition subsystem. Using the property of differential flatness, a dynamic feedback compensator can be designed for the system, thereby extending the system into a linear form. The presented control algorithm for reference tracking combines a feedforward and a feedback loop, the structure also known as a two DOF control scheme. The feedforward part should drive the system to the vicinity of the reference trajectory and the feedback part should eliminate any errors that occur due to noise and other disturbances etc. The feedforward control can never achieve accurate reference following, but this deficiency can be eliminated with the introduction of the feedback loop. The design of the model predictive control is based on the linear error model. The model predictive control is given in analytical form, so the computational burden is kept at a reasonable level for real-time implementation. The control algorithm requires that a reference trajectory is at least twice differentiable function. A suitable approach to design such a trajectory is by exploiting some useful properties of the Bernstein-Bézier parametric curves. The simulation experiments as well as real system experiments on a robot normally used in the

  16. Disruption of visual circuit formation and refinement in a mouse model of autism.

    Science.gov (United States)

    Cheng, Ning; Khanbabaei, Maryam; Murari, Kartikeya; Rho, Jong M

    2017-02-01

    Aberrant connectivity is believed to contribute to the pathophysiology of autism spectrum disorder (ASD). Recent neuroimaging studies have increasingly identified such impairments in patients with ASD, including alterations in sensory systems. However, the cellular substrates and molecular underpinnings of disrupted connectivity remain poorly understood. Utilizing eye-specific segregation in the dorsal lateral geniculate nucleus (dLGN) as a model system, we investigated the formation and refinement of precise patterning of synaptic connections in the BTBR T + tf/J (BTBR) mouse model of ASD. We found that at the neonatal stage, the shape of the dLGN occupied by retinal afferents was altered in the BTBR group compared to C57BL/6J (B6) animals. Notably, the degree of overlap between the ipsi- and contralateral afferents was significantly greater in the BTBR mice. Moreover, these abnormalities continued into mature stage in the BTBR animals, suggesting persistent deficits rather than delayed maturation of axonal refinement. Together, these results indicate disrupted connectivity at the synaptic patterning level in the BTBR mice, suggesting that in general, altered neural circuitry may contribute to autistic behaviours seen in this animal model. In addition, these data are consistent with the notion that lower-level, primary processing mechanisms contribute to altered visual perception in ASD. Autism Res 2017, 10: 212-223. © 2016 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research. © 2016 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research.

  17. Visual Complexity in Orthographic Learning: Modeling Learning across Writing System Variations

    Science.gov (United States)

    Chang, Li-Yun; Plaut, David C.; Perfetti, Charles A.

    2016-01-01

    The visual complexity of orthographies varies across writing systems. Prior research has shown that complexity strongly influences the initial stage of reading development: the perceptual learning of grapheme forms. This study presents a computational simulation that examines the degree to which visual complexity leads to grapheme learning…

  18. Individuals with Visual Impairments Teaching in Nepal's Mainstream Schools: A Model for Inclusion

    Science.gov (United States)

    Lamichhane, Kamal

    2016-01-01

    This paper explores the challenges and strengths of teachers with a visual impairments teaching in Nepal's mainstream schools, using qualitative interviews of teachers and principals, as well as a student survey data set. Results showed that teachers with visual impairments tend not to teach subjects such as science and mathematics that require…

  19. Assessing public concern for landscape quality: a potential model to identify visual thresholds

    Science.gov (United States)

    Arthur W. Magill

    1990-01-01

    Considerable public criticism and sometimes legal obstructions have been directed toward landscape management in relation to the extraction of natural resources. Many managers do not understand public concerns for visually attractive resources. Managers need to know when landscape alterations, like clearcuts, attract public attention and become visually objectionable....

  20. Evolution of a visual impact model to evaluate nuclear plant siting and design option

    Science.gov (United States)

    Brian A. Gray; John Ady; Grant R. Jones

    1979-01-01

    The development of a visual impact method- elegy is reviewed from first concepts (1973) to application.3/ The method can be used to train evaluators to use explicit criteria (vividness, intactness and unity) to assess change in a setting's visual quality as the result of construction of a nuclear facility, or any other visible alteration. Slides of "before...

  1. Can theory be embedded in visual interventions to promote self-management? A proposed model and worked example.

    Science.gov (United States)

    Williams, B; Anderson, A S; Barton, K; McGhee, J

    2012-12-01

    Nurses are increasingly involved in a range of strategies to encourage patient behaviours that improve self-management. If nurses are to be involved in, or indeed lead, the development of such interventions then processes that enhance the likelihood that they will lead to evidence that is both robust and usable in practice are required. Although behavioural interventions have been predominantly based on written text or the spoken word increasing numbers are now drawing on visual media to communicate their message, despite only a growing evidence base to support it. The use of such media in health interventions is likely to increase due to technological advances enabling easier and cheaper production, and an increasing social preference for visual forms of communication. However, the development of such media is often highly pragmatic and developed intuitively rather than with theory and evidence informing their content and form. Such a process may be at best inefficient and at worst potentially harmful. This paper performs two functions. Firstly, it discusses and argues why visual based interventions may be a powerful media for behaviour change; and secondly, it proposes a model, developed from the MRC Framework for the Development and Evaluation of Complex Interventions, to guide the creation of theory informed visual interventions. It employs a case study of the development of an intervention to motivate involvement in a lifestyle intervention among people with increased cardiovascular risk. In doing this we argue for a step-wise model which includes: (1) the identification of a theoretical basis and associated concepts; (2) the development of visual narrative to establish structure; (3) the visual rendering of narrative and concepts; and (4) the assessment of interpretation and impact among the intended patient group. We go on to discuss the theoretical and methodological limitations of the model. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. 3D Visualization of Hydrological Model Outputs For a Better Understanding of Multi-Scale Phenomena

    Science.gov (United States)

    Richard, J.; Schertzer, D. J. M.; Tchiguirinskaia, I.

    2014-12-01

    During the last decades, many hydrological models has been created to simulate extreme events or scenarios on catchments. The classical outputs of these models are 2D maps, time series or graphs, which are easily understood by scientists, but not so much by many stakeholders, e.g. mayors or local authorities, and the general public. One goal of the Blue Green Dream project is to create outputs that are adequate for them. To reach this goal, we decided to convert most of the model outputs into a unique 3D visualization interface that combines all of them. This conversion has to be performed with an hydrological thinking to keep the information consistent with the context and the raw outputs.We focus our work on the conversion of the outputs of the Multi-Hydro (MH) model, which is physically based, fully distributed and with a GIS data interface. MH splits the urban water cycle into 4 components: the rainfall, the surface runoff, the infiltration and the drainage. To each of them, corresponds a modeling module with specific inputs and outputs. The superimposition of all this information will highlight the model outputs and help to verify the quality of the raw input data. For example, the spatial and the time variability of the rain generated by the rainfall module will be directly visible in 4D (3D + time) before running a full simulation. It is the same with the runoff module: because the result quality depends of the resolution of the rasterized land use, it will confirm or not the choice of the cell size.As most of the inputs and outputs are GIS files, two main conversions will be applied to display the results into 3D. First, a conversion from vector files to 3D objects. For example, buildings are defined in 2D inside a GIS vector file. Each polygon can be extruded with an height to create volumes. The principle is the same for the roads but an intrusion, instead of an extrusion, is done inside the topography file. The second main conversion is the raster

  3. Visualization of finite element model solutions for defibrillation voltage and current distributions

    Science.gov (United States)

    Jantz, Steven J.

    1994-12-01

    The objective of this project was to begin filling the need for visualization. A set of tools has been developed to aid in analyzing the results of our FEM computations. Tools facilitating the display of both scalar and vector quantities were included. The toolset was developed utilizing the graphics routines and features available in a commercial scientific visualization package - the Application Visualization System (AVS) . The attempt was made to give the user as much control over the visualization environment as possible with a minimum amount of knowledge of the underlying software. The project was begun on an IBM RS6OOO computer. During the toolset development, the work was ported to a SUN SPARCstation 20 and it was completed there. This thesis describes the development of these visualization tools for use in the AVS environment.

  4. PhasePlot: A Software Program for Visualizing Phase Relations Computed Using Thermochemical Models and Databases

    Science.gov (United States)

    Ghiorso, M. S.

    2011-12-01

    A new software program has been developed for Macintosh computers that permits the visualization of phase relations calculated from thermodynamic data-model collections. The data-model collections of MELTS (Ghiorso and Sack, 1995, CMP 119, 197-212), pMELTS (Ghiorso et al., 2002, G-cubed 3, 10.1029/2001GC000217) and the deep mantle database of Stixrude and Lithgow-Bertelloni (2011, GJI 184, 1180-1213) are currently implemented. The software allows users to enter a system bulk composition and a range of reference conditions and then calculate a grid of phase relations. These relations may be visualized in a variety of ways including phase diagrams, phase proportion plots, and contour diagrams of phase compositions and abundances. Results may be exported into Excel or similar spreadsheet applications. Flexibility in stipulating reference conditions permit the construction of temperature-pressure, temperature-volume, entropy-pressure, or entropy-volume display grids. Calculations on the grid are performed for fixed bulk composition or in open systems governed by user specified constraints on component chemical potentials (e.g., specified oxygen fugacity buffers). The calculation engine for the software is optimized for multi-core compute architectures and is very fast, allowing a typical grid of 64 points to be calculated in under 10 seconds on a dual-core laptop/iMac. The underlying computational thermodynamic algorithms have been optimized for speed and robust behavior. Taken together, both of these advances facilitate in classroom demonstrations and permit novice users to work with the program effectively, focusing on problem specification and interpretation of results rather than on manipulation and mechanics of computation - a key feature of an effective instructional tool. The emphasis in this software package is graphical visualization, which aids in better comprehension of complex phase relations in multicomponent systems. Anecdotal experience in using Phase

  5. Nonlinear dynamic model for visual object tracking on Grassmann manifolds with partial occlusion handling.

    Science.gov (United States)

    Khan, Zulfiqar Hasan; Gu, Irene Yu-Hua

    2013-12-01

    This paper proposes a novel Bayesian online learning and tracking scheme for video objects on Grassmann manifolds. Although manifold visual object tracking is promising, large and fast nonplanar (or out-of-plane) pose changes and long-term partial occlusions of deformable objects in video remain a challenge that limits the tracking performance. The proposed method tackles these problems with the main novelties on: 1) online estimation of object appearances on Grassmann manifolds; 2) optimal criterion-based occlusion handling for online updating of object appearances; 3) a nonlinear dynamic model for both the appearance basis matrix and its velocity; and 4) Bayesian formulations, separately for the tracking process and the online learning process, that are realized by employing two particle filters: one is on the manifold for generating appearance particles and another on the linear space for generating affine box particles. Tracking and online updating are performed in an alternating fashion to mitigate the tracking drift. Experiments using the proposed tracker on videos captured by a single dynamic/static camera have shown robust tracking performance, particularly for scenarios when target objects contain significant nonplanar pose changes and long-term partial occlusions. Comparisons with eight existing state-of-the-art/most relevant manifold/nonmanifold trackers with evaluations have provided further support to the proposed scheme.

  6. Impaired Limbic Cortico-Striatal Structure and Sustained Visual Attention in a Rodent Model of Schizophrenia

    Science.gov (United States)

    Barnes, Samuel A.; Sawiak, Stephen J.; Caprioli, Daniele; Jupp, Bianca; Buonincontri, Guido; Mar, Adam C.; Harte, Michael K.; Fletcher, Paul C.; Robbins, Trevor W.; Neill, Jo C.

    2015-01-01

    Background: N-methyl-d-aspartate receptor (NMDAR) dysfunction is thought to contribute to the pathophysiology of schizophrenia. Accordingly, NMDAR antagonists such as phencyclidine (PCP) are used widely in experimental animals to model cognitive impairment associated with this disorder. However, it is unclear whether PCP disrupts the structural integrity of brain areas relevant to the profile of cognitive impairment in schizophrenia. Methods: Here we used high-resolution magnetic resonance imaging and voxel-based morphometry to investigate structural alterations associated with sub-chronic PCP treatment in rats. Results: Sub-chronic exposure of rats to PCP (5mg/kg twice daily for 7 days) impaired sustained visual attention on a 5-choice serial reaction time task, notably when the attentional load was increased. In contrast, sub-chronic PCP had no significant effect on the attentional filtering of a pre-pulse auditory stimulus in an acoustic startle paradigm. Voxel-based morphometry revealed significantly reduced grey matter density bilaterally in the hippocampus, anterior cingulate cortex, ventral striatum, and amygdala. PCP-treated rats also exhibited reduced cortical thickness in the insular cortex. Conclusions: These findings demonstrate that sub-chronic NMDA receptor antagonism is sufficient to produce highly-localized morphological abnormalities in brain areas implicated in the pathogenesis of schizophrenia. Furthermore, PCP exposure resulted in dissociable impairments in attentional function. PMID:25552430

  7. Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

    Science.gov (United States)

    Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

    2016-03-01

    Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

  8. Quantitative Visualization of Leukocyte Infiltrate in a Murine Model of Fulminant Myocarditis by Light Sheet Microscopy.

    Science.gov (United States)

    Männ, Linda; Klingberg, Anika; Gunzer, Matthias; Hasenberg, Mike

    2017-05-31

    Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently labelled structures in large biological specimens, and is down to cellular resolution. Meanwhile, the constant refinement of underlying protocols and the enhanced availability of specialized commercial systems enable us to investigate the microstructure of whole mouse organs and even allow for the characterization of cellular behavior in various live-cell imaging approaches. Here, we describe a protocol for the spatial whole-mount visualization and quantification of the CD45+ leukocyte population in inflamed mouse hearts. The method employs a transgenic mouse strain (CD11c.DTR)that has recently been shown to serve as a robust, inducible model for the study of the development of fulminant fatal myocarditis, characterized by lethal cardiac arrhythmias. This protocol includes myocarditis induction, intravital antibody-mediated cell staining, organ preparation, and LSFM with subsequent computer-assisted image post-processing. Although presented as a highly-adapted method for our particular scientific question, the protocol represents the blueprint of an easily adjustable system that can also target completely different fluorescent structures in other organs and even in other species.

  9. 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.

  10. Misleading population estimates: biases and consistency of visual surveys and matrix modelling in the endangered bearded vulture.

    Directory of Open Access Journals (Sweden)

    Antoni Margalida

    Full Text Available Conservation strategies for long-lived vertebrates require accurate estimates of parameters relative to the populations' size, numbers of non-breeding individuals (the "cryptic" fraction of the population and the age structure. Frequently, visual survey techniques are used to make these estimates but the accuracy of these approaches is questionable, mainly because of the existence of numerous potential biases. Here we compare data on population trends and age structure in a bearded vulture (Gypaetus barbatus population from visual surveys performed at supplementary feeding stations with data derived from population matrix-modelling approximations. Our results suggest that visual surveys overestimate the number of immature (6 y.o. were underestimated in comparison with the predictions of a population model using a stable-age distribution. In addition, we found that visual surveys did not provide conclusive information on true variations in the size of the focal population. Our results suggest that although long-term studies (i.e. population matrix modelling based on capture-recapture procedures are a more time-consuming method, they provide more reliable and robust estimates of population parameters needed in designing and applying conservation strategies. The findings shown here are likely transferable to the management and conservation of other long-lived vertebrate populations that share similar life-history traits and ecological requirements.

  11. Brain circuits underlying visual stability across eye movements - converging evidence for a neuro-computational model of area LIP

    Directory of Open Access Journals (Sweden)

    Arnold eZiesche

    2014-03-01

    Full Text Available The understanding of the subjective experience of a visually stable world despite the occurrence of an observer's eye movements has been the focus of extensive research for over 20 years. These studies have revealed fundamental mechanisms such as anticipatory receptive field shifts and the saccadic suppression of stimulus displacements, yet there currently exists no single explanatory framework for these observations. We show that a previously presented neuro-computational model of peri-saccadic mislocalization accounts for the phenomenon of predictive remapping and for the observation of saccadic suppression of displacement (SSD. This converging evidence allows us to identify the potential ingredients of perceptual stability that generalize beyond different data sets in a formal physiology-based model. In particular we propose that predictive remapping stabilizes the visual world across saccades by introducing a feedback loop and, as an emergent result, small displacements of stimuli are not noticed by the visual system. The model provides a link from neural dynamics, to neural mechanism and finally to behavior, and thus offers a testable comprehensive framework of visual stability.

  12. The effect of synaptic plasticity on orientation selectivity in a balanced model of primary visual cortex

    Science.gov (United States)

    Gonzalo Cogno, Soledad; Mato, Germán

    2015-01-01

    Orientation selectivity is ubiquitous in the primary visual cortex (V1) of mammals. In cats and monkeys, V1 displays spatially ordered maps of orientation preference. Instead, in mice, squirrels, and rats, orientation selective neurons in V1 are not spatially organized, giving rise to a seemingly random pattern usually referred to as a salt-and-pepper layout. The fact that such different organizations can sharpen orientation tuning leads to question the structural role of the intracortical connections; specifically the influence of plasticity and the generation of functional connectivity. In this work, we analyze the effect of plasticity processes on orientation selectivity for both scenarios. We study a computational model of layer 2/3 and a reduced one-dimensional model of orientation selective neurons, both in the balanced state. We analyze two plasticity mechanisms. The first one involves spike-timing dependent plasticity (STDP), while the second one considers the reconnection of the interactions according to the preferred orientations of the neurons. We find that under certain conditions STDP can indeed improve selectivity but it works in a somehow unexpected way, that is, effectively decreasing the modulated part of the intracortical connectivity as compared to the non-modulated part of it. For the reconnection mechanism we find that increasing functional connectivity leads, in fact, to a decrease in orientation selectivity if the network is in a stable balanced state. Both counterintuitive results are a consequence of the dynamics of the balanced state. We also find that selectivity can increase due to a reconnection process if the resulting connections give rise to an unstable balanced state. We compare these findings with recent experimental results. PMID:26347615

  13. A morphologically preserved multi-resolution TIN surface modeling and visualization method for virtual globes

    Science.gov (United States)

    Zheng, Xianwei; Xiong, Hanjiang; Gong, Jianya; Yue, Linwei

    2017-07-01

    Virtual globes play an important role in representing three-dimensional models of the Earth. To extend the functioning of a virtual globe beyond that of a ;geobrowser;, the accuracy of the geospatial data in the processing and representation should be of special concern for the scientific analysis and evaluation. In this study, we propose a method for the processing of large-scale terrain data for virtual globe visualization and analysis. The proposed method aims to construct a morphologically preserved multi-resolution triangulated irregular network (TIN) pyramid for virtual globes to accurately represent the landscape surface and simultaneously satisfy the demands of applications at different scales. By introducing cartographic principles, the TIN model in each layer is controlled with a data quality standard to formulize its level of detail generation. A point-additive algorithm is used to iteratively construct the multi-resolution TIN pyramid. The extracted landscape features are also incorporated to constrain the TIN structure, thus preserving the basic morphological shapes of the terrain surface at different levels. During the iterative construction process, the TIN in each layer is seamlessly partitioned based on a virtual node structure, and tiled with a global quadtree structure. Finally, an adaptive tessellation approach is adopted to eliminate terrain cracks in the real-time out-of-core spherical terrain rendering. The experiments undertaken in this study confirmed that the proposed method performs well in multi-resolution terrain representation, and produces high-quality underlying data that satisfy the demands of scientific analysis and evaluation.

  14. Visual comparison for information visualization

    KAUST Repository

    Gleicher, M.

    2011-09-07

    Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

  15. Developmental changes in reading do not alter the development of visual processing skills: An application of explanatory item response models in grades K-2

    Directory of Open Access Journals (Sweden)

    Kristi L Santi

    2015-02-01

    Full Text Available Visual processing has been widely studied in regard to its impact on a students’ ability to read. A less researched area is the role of reading in the development of visual processing skills. A cohort-sequential, accelerated-longitudinal design was utilized with 932 kindergarten, first, and second grade students to examine the impact of reading acquisition on the processing of various types of visual discrimination and visual motor test items. Students were assessed four times per year on a variety of reading measures and reading precursors and two popular measures of visual processing over a three-year period. Explanatory item response models were used to examine the roles of person and item characteristics on changes in visual processing abilities and changes in item difficulties over time. Results showed different developmental patterns for five types of visual processing test items, but most importantly failed to show consistent effects of learning to read on changes in item difficulty. Thus, the present study failed to find support for the hypothesis that learning to read alters performance on measures of visual processing. Rather, visual processing and reading ability improved together over time with no evidence to suggest cross-domain influences from reading to visual processing. Results are discussed in the context of developmental theories of visual processing and brain-based research on the role of visual skills in learning to read.

  16. Toward a Visualization-Supported Workflow for Cyber Alert Management using Threat Models and Human-Centered Design

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, Lyndsey; Pirrung, Megan A.; Blaha, Leslie M.; Dowling, Michelle V.; Feng, Mi

    2017-10-09

    Cyber network analysts follow complex processes in their investigations of potential threats to their network. Much research is dedicated to providing automated tool support in the effort to make their tasks more efficient, accurate, and timely. This tool support comes in a variety of implementations from machine learning algorithms that monitor streams of data to visual analytic environments for exploring rich and noisy data sets. Cyber analysts, however, often speak of a need for tools which help them merge the data they already have and help them establish appropriate baselines against which to compare potential anomalies. Furthermore, existing threat models that cyber analysts regularly use to structure their investigation are not often leveraged in support tools. We report on our work with cyber analysts to understand they analytic process and how one such model, the MITRE ATT&CK Matrix [32], is used to structure their analytic thinking. We present our efforts to map specific data needed by analysts into the threat model to inform our eventual visualization designs. We examine data mapping for gaps where the threat model is under-supported by either data or tools. We discuss these gaps as potential design spaces for future research efforts. We also discuss the design of a prototype tool that combines machine-learning and visualization components to support cyber analysts working with this threat model.

  17. Creative user-centered visualization design for energy analysts and modelers.

    Science.gov (United States)

    Goodwin, Sarah; Dykes, Jason; Jones, Sara; Dillingham, Iain; Dove, Graham; Duffy, Alison; Kachkaev, Alexander; Slingsby, Aidan; Wood, Jo

    2013-12-01

    We enhance a user-centered design process with techniques that deliberately promote creativity to identify opportunities for the visualization of data generated by a major energy supplier. Visualization prototypes developed in this way prove effective in a situation whereby data sets are largely unknown and requirements open - enabling successful exploration of possibilities for visualization in Smart Home data analysis. The process gives rise to novel designs and design metaphors including data sculpting. It suggests: that the deliberate use of creativity techniques with data stakeholders is likely to contribute to successful, novel and effective solutions; that being explicit about creativity may contribute to designers developing creative solutions; that using creativity techniques early in the design process may result in a creative approach persisting throughout the process. The work constitutes the first systematic visualization design for a data rich source that will be increasingly important to energy suppliers and consumers as Smart Meter technology is widely deployed. It is novel in explicitly employing creativity techniques at the requirements stage of visualization design and development, paving the way for further use and study of creativity methods in visualization design.

  18. Reading The Sun: A Three Dimensional Visual Model of The Solar Environment During Solar Cycle 24

    Science.gov (United States)

    Carranza-fulmer, T. L.; Moldwin, M.

    2014-12-01

    The sun is a powerful force that has proven to our society that it has a large impact on our lives. Unfortunately, there is still a lack of awareness on how the sun is capable of affecting Earth. The over all idea of "Reading The Sun" installation is to help demonstrate how the sun impacts the Earth, by compiling various data sources from satellites (SOHO, SDO, and STERO) with solar and solar wind models (MAS and ENLIL) to create a comprehensive three dimensional display of the solar environment. It focuses on the current solar maximum of solar cycle 24 and a CME that impacted Earth's magnetic field on February 27, 2014, which triggered geomagnetic storms around the Earth's poles. The CME was an after-effect of a class X4.9 solar flare, which was released from the sun on February 25, 2014. "Reading The Sun" is a 48" x 48" x 48" hanging model of the sun with color coded open opposing magnetic field lines along with various layers of the solar atmosphere, the heliospheric current sheet, and the inner planets. At the center of the xyz axis is the sun with the open magnetic field lines and the heliospheric current sheet permeating inner planetary space. The xyz axes are color coded to represent various types of information with corresponding visual images for the viewer to be able to read the model. Along the z-axis are three colors (yellow, orange, and green) that represent the different layers of the solar atmosphere (photosphere, chromosphere, and corona) that correspond to three satellite images in various spectrums related to a CME and Solar Flare and the xy-plane shows where the inner planets are in relation to the sun. The exhibit in which "Reading The Sun "is being displayed is called, The Rotation of Language at the Wheather Again Gallery in Rockaway, New York. The intent of the exhibit is to both celebrate as well as present a cautionary tale on the ability of human language to spark and ignite the individual and collective imagination towards an experience

  19. Fourier power, subjective distance and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Directory of Open Access Journals (Sweden)

    Mark Daniel Lescroart

    2015-11-01

    Full Text Available Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA, Retrosplenial Complex (RSC, and the Occipital Place Area (OPA. It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1 2D features related to Fourier power; (2 3D spatial features such as the distance to objects in a scene; or (3 abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM to BOLD fMRI responses elicited by a set of 1,386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue.

  20. Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Science.gov (United States)

    Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

    2015-01-01

    Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

  1. Genomics Analogy Model for Educators (GAME): Fuzzy DNA Model to Enable the Learning of Gene Sequencing by Visually-Impaired and Blind Students

    Science.gov (United States)

    Butler, Charles; Bello, Julia; York, Alan; Orvis, Kathryn; Pittendrigh, Barry R.

    2008-01-01

    Much of the general population is aware of terms such as biotechnology, genetic engineering, and genomics. However, there is a lack of understanding concerning these fields among many secondary school students. Few teaching models exist to explain concepts behind genomics and even less are available for teaching the visually impaired and blind.…

  2. Cariogram Model in Assessment of Dental Caries among Mentally Challenged and Visually Impaired Individuals of Udaipur, India.

    Science.gov (United States)

    Daryani, Hemasha; Nagarajappa, Ramesh; Sharda, Archana J; Asawa, Kailash; Tak, Mridula; Sanadhya, Sudhanshu; Batra, Mehak

    2014-01-01

    To assess the caries risk and contribution of diet, bacteria, circumstances and susceptibility sectors among special groups in comparison to the normal group of Udaipur using the Cariogram model. A Cariogram model was used to identify risk factors among 160 subjects (40 mentally challenged, 60 visually impaired and 60 normal healthy individuals) aged 7-36 years. Statistical analysis was done using Chi-square/ Fischer's Exact followed by Marascuilo procedure and Stepwise multiple linear regression. Compared to the normal group (74%), mentally challenged (33%) and visually impaired (41%) groups showed less chances of avoiding future caries. Group (R= 0.660) was found to be strongest predictor for caries risk. Susceptibility sector contributed 61% for caries risk in all the groups. The caries risk was high among special groups compared to normal group. Susceptibility sector illustrated the highest contribution for caries risk in all groups.

  3. Cariogram Model in Assessment of Dental Caries among Mentally Challenged and Visually Impaired Individuals of Udaipur, India

    Science.gov (United States)

    Daryani, Hemasha; Nagarajappa, Ramesh; Sharda, Archana J; Asawa, Kailash; Tak, Mridula; Sanadhya, Sudhanshu; Batra, Mehak

    2014-01-01

    Objectives: To assess the caries risk and contribution of diet, bacteria, circumstances and susceptibility sectors among special groups in comparison to the normal group of Udaipur using the Cariogram model. Materials and Methods: A Cariogram model was used to identify risk factors among 160 subjects (40 mentally challenged, 60 visually impaired and 60 normal healthy individuals) aged 7-36 years. Statistical analysis was done using Chi-square/ Fischer’s Exact followed by Marascuilo procedure and Stepwise multiple linear regression. Results: Compared to the normal group (74%), mentally challenged (33%) and visually impaired (41%) groups showed less chances of avoiding future caries. Group (R= 0.660) was found to be strongest predictor for caries risk. Susceptibility sector contributed 61% for caries risk in all the groups. Conclusion: The caries risk was high among special groups compared to normal group. Susceptibility sector illustrated the highest contribution for caries risk in all groups. PMID:24596776

  4. NewsPaperBox - Online News Space: a visual model for representing the social space of a website

    Directory of Open Access Journals (Sweden)

    Selçuk Artut

    2010-02-01

    Full Text Available NewsPaperBox * propounds an alternative visual model utilizing the treemap algorithm to represent the collective use of a website that evolves in response to user interaction. While the technology currently exists to track various user behaviors such as number of clicks, duration of stay on a given web site, these statistics are not yet employed to influence the visual representation of that site's design in real time. In that sense, this project propounds an alternative modeling of a representational outlook of a website that is developed by collaborations and competitions of its global users. This paper proposes the experience of cyberspace as a generative process driven by its effective user participation.

  5. CAChe Molecular Modeling: A Visualization Tool Early in the Undergraduate Chemistry Curriculum

    Science.gov (United States)

    Crouch, R. David; Holden, Michael S.; Samet, Cindy

    1996-10-01

    In Dickinson's chemistry curriculum, "Synthesis & Reactivity" replaces the traditional organic chemistry sequence and begins in the second semester of the freshman year. A key aspect of our sequence is the correlation of laboratory experiments with lecture topics and the extension of laboratory exercises beyond the usual 4-hour period. With this goal in mind, a number of "Synthesis & Reactivity" experiments have been developed that include an out-of-class computational chemistry exercise using CAChe (1), a versatile molecular modeling software package. Because the first semester of "Synthesis & Reactivity" has a large number of freshmen, emphasis is placed on developing an insight for where nucleophiles and electrophiles might attack a molecule. The Visualizer+ routine in CAChe generates striking graphical images of these sites and the reaction of NBS/H2O with 3-sulfolene (2) presents an excellent opportunity to introduce CAChe into an experiment. Before the laboratory, students are introduced to CAChe to determine how NBS might interact with a nucleophile such as an alkene. Students then return to the laboratory to perform the bromohydrin synthesis but are asked to consider what the regiochemistry would be were the alkene not symmetric. Specifically, students are instructed to visit the computer laboratory during the week and perform calculations on the bromonium ion formed from 2-methylpropene to determine where a nucleophilic H2O molecule might attack. The MOPAC routine in CAChe provides data that are converted to a graphical depiction of the frontier density of the intermediate, indicating potential reactive sites based on electron distribution of orbitals near the HOMO and LUMO. When these data are manipulated by Visualizer+, the obvious conclusion is that the nucleophilic water molecule should attack the more highly substituted carbon of the bromonium ion (Fig. 1) and generate one regioisomer. Figure 1. Relative nucleophilic susceptibilities ofr the

  6. Visual Impairment

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Visual Impairment KidsHealth / For Teens / Visual Impairment What's in ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual ...

  7. Visual field

    Science.gov (United States)

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam. This is a quick and basic check of the visual field. The health care provider ...

  8. Using a visual programming language to bridge the cognitive gap between a novice's mental model and program code

    Science.gov (United States)

    Smith, Bryan J.

    Current research suggests that many students do not know how to program very well at the conclusion of their introductory programming course. We believe that a reason novices have such difficulties learning programming is because engineering novices often learn through a lecture format where someone with programming knowledge lectures to novices, the novices attempt to absorb the content, and then reproduce it during exams. By primarily appealing to programming novices who prefer to understand visually, we research whether programming novices understand programming better if computer science concepts are presented using a visual programming language than if these programs are presented using a text-based programming language. This method builds upon previous research that suggests that most engineering students are visual learners, and we propose that using a flow-based visual programming language will address some of the most important and difficult topics to novices of programming. We use an existing flow-model tool, RAPTOR, to test this method, and share the program understanding results using this theory.

  9. Simultaneous visualization of transonic buffet on a rocket faring model using unsteady PSP measurement and Schlieren method

    Science.gov (United States)

    Nakakita, K.

    2017-02-01

    Simultaneous visualization technique of the combination of the unsteady Pressure-Sensitive Paint and the Schlieren measurement was introduced. It was applied to a wind tunnel test of a rocket faring model at the JAXA 2mx2m transonic wind tunnel. Quantitative unsteady pressure field was acquired by the unsteady PSP measurement, which consisted of a high-speed camera, high-power laser diode, and so on. Qualitative flow structure was acquired by the Schlieren measurement using a high-speed camera and Xenon lamp with a blue optical filter. Simultaneous visualization was achieved 1.6 kfps frame rate and it gave the detailed structure of unsteady flow fields caused by the unsteady shock wave oscillation due to shock-wave/boundary-layer interaction around the juncture between cone and cylinder on the model. Simultaneous measurement results were merged into a movie including surface pressure distribution on the rocket faring and spatial structure of shock wave system concerning to transonic buffet. Constructed movie gave a timeseries and global information of transonic buffet flow field on the rocket faring model visually.

  10. Standardization of seismic tomographic models and earthquake focal mechanisms data sets based on web technologies, visualization with keyhole markup language

    Science.gov (United States)

    Postpischl, Luca; Danecek, Peter; Morelli, Andrea; Pondrelli, Silvia

    2011-01-01

    We present two projects in seismology that have been ported to web technologies, which provide results in Keyhole Markup Language (KML) visualization layers. These use the Google Earth geo-browser as the flexible platform that can substitute specialized graphical tools to perform qualitative visual data analyses and comparisons. The Network of Research Infrastructures for European Seismology (NERIES) Tomographic Earth Model Repository contains data sets from over 20 models from the literature. A hierarchical structure of folders that represent the sets of depths for each model is implemented in KML, and this immediately results into an intuitive interface for users to navigate freely and to compare tomographic plots. The KML layer for the European-Mediterranean Regional Centroid-Moment Tensor Catalog displays the focal mechanism solutions or moderate-magnitude Earthquakes from 1997 to the present. Our aim in both projects was to also propose standard representations of scientific data sets. Here, the general semantic approach of an XML framework has an important impact that must be further explored, although we find the KML syntax to more emphasis on aspects of detailed visualization. We have thus used, and propose the use of, Javascript Object Notation (JSON), another semantic notation that stems from the web-development community that provides a compact, general-purpose, data-exchange format.

  11. Test technique development in interference free testing, flow visualization, and remote control model technology at Langley's Unitary Plan wind tunnel

    Science.gov (United States)

    Corlett, W. A.

    1979-01-01

    A metric half-span model is considered as a means of mechanical support for a wind-tunnel model which allows measurement of aerodynamic forces and moments without support interference or model distortion. This technique can be applied to interference-free propulsion models. The vapor screen method of flow visualization at supersonic Mach numbers is discussed. The use of smoke instead of water vapor as a medium to produce the screen is outlined. Vapor screen data are being used in the development of analytical vortex tracking programs. Test results for a remote control model system are evaluated. Detailed control effectiveness and cross-coupling data were obtained with a single run. For the afterbody tail configuration, tested control boundaries at several roll orientations were established utilizing the facility's on-line capability to 'fly' the model in the wind tunnel.

  12. Goat Model for Direct Visualizing the Effectiveness of Detaching Sinus Mucosa in Real Time During Crestal Maxillary Sinus Floor Elevation.

    Science.gov (United States)

    Fan, Jiadong; Hu, Pin; Li, Yanfeng; Wang, Fuli; Dong, Xinming; Liu, Bin; Liu, Le; Zhang, Yue; Gu, Xiangmin

    2017-08-01

    The procedure of crestal maxillary sinus floor elevation presents a great challenge to the field of implant dentistry. Due to the limited visualization in this procedure, the effectiveness of detaching sinus mucosa could not be assessed in real time. We recently developed an ex vivo goat sinus model by cutting the goat residual skulls along four lines determined from computerized tomography (CT) scans, extracting the maxillary premolar or molar teeth, and preparing implant socket in the maxilla. The generated ex vivo goat sinus models exposed the maxilla and the whole maxillary sinus mucosa, thus enabling real-time observation of detaching maxillary sinus mucosa via directly visualizing the working situation of sinus lift tool in the models and directly measuring the length of detached mucosa and space volume generated under the elevated sinus mucosa. One commercially available umbrella-shaped sinus lift curette was used to detach the maxillary sinus mucosa to evaluate the effectiveness of the ex vivo goat sinus models. The results showed that this curette could detach the sinus mucosa 3.75 mm in length in the mesiodistal direction and 2.81 mm in the buccal-palatal direction. Moreover, a space volume of 52.7 μl could be created under the elevated sinus mucosa in the goat ex vivo models. All the experimental results suggested that this ex vivo goat sinus model might be useful in the evaluation of improved or newly designed sinus lift tools for elevating the maxillary sinus mucosa via the crestal approach.

  13. Landscaping analyses of the ROC predictions of discrete-slots and signal-detection models of visual working memory.

    Science.gov (United States)

    Donkin, Chris; Tran, Sophia Chi; Nosofsky, Robert

    2014-10-01

    A fundamental issue concerning visual working memory is whether its capacity limits are better characterized in terms of a limited number of discrete slots (DSs) or a limited amount of a shared continuous resource. Rouder et al. (2008) found that a mixed-attention, fixed-capacity, DS model provided the best explanation of behavior in a change detection task, outperforming alternative continuous signal detection theory (SDT) models. Here, we extend their analysis in two ways: first, with experiments aimed at better distinguishing between the predictions of the DS and SDT models, and second, using a model-based analysis technique called landscaping, in which the functional-form complexity of the models is taken into account. We find that the balance of evidence supports a DS account of behavior in change detection tasks but that the SDT model is best when the visual displays always consist of the same number of items. In our General Discussion section, we outline, but ultimately reject, a number of potential explanations for the observed pattern of results. We finish by describing future research that is needed to pinpoint the basis for this observed pattern of results.

  14. PRISMA-MAR: An Architecture Model for Data Visualization in Augmented Reality Mobile Devices

    Science.gov (United States)

    Gomes Costa, Mauro Alexandre Folha; Serique Meiguins, Bianchi; Carneiro, Nikolas S.; Gonçalves Meiguins, Aruanda Simões

    2013-01-01

    This paper proposes an extension to mobile augmented reality (MAR) environments--the addition of data charts to the more usual text, image and video components. To this purpose, we have designed a client-server architecture including the main necessary modules and services to provide an Information Visualization MAR experience. The server side…

  15. How patients experience progressive loss of visual function: a model of adjustment using qualitative methods

    OpenAIRE

    Hayeems, R Z; Geller, G.; Finkelstein, D; Faden, R. R.

    2005-01-01

    Background: People with retinitis pigmentosa (RP) experience functional and psychological challenges as they adjust to progressive loss of visual function. The authors aimed to understand better the process of adjusting to RP in light of the emotional suffering associated with this process.

  16. Towards a comprehensive model for predicting the quality of individual visual experience

    NARCIS (Netherlands)

    Zhu, Y.; Heynderickx, I.E.J.R.; Hanjalic, A.; Redi, J.A.

    2015-01-01

    Recently, a lot of effort has been devoted to estimating the Quality of Visual Experience (QoVE) in order to optimize video delivery to the user. For many decades, existing objective metrics mainly focused on estimating the perceived quality of a video, i.e., the extent to which artifacts due to

  17. Pairwise-Distance-Analysis-Driven Dimensionality Reduction Model with Double Mappings for Hyperspectral Image Visualization

    Directory of Open Access Journals (Sweden)

    Yi Long

    2015-06-01

    Full Text Available This paper describes a novel strategy for the visualization of hyperspectral imagery based on the analysis of image pixel pairwise distances. The goal of this approach is to generate a final color image with excellent interpretability and high contrast at the cost of distorting a few pairwise distances. Specifically, the principle of equal variance is introduced to divide all hyperspectral bands into three subgroups and to ensure the energy is distributed uniformly between them, as in natural color images. Then, after detecting both normal and outlier pixels, these three subgroups are mapped into three color components of the output visualization using two different mapping (i.e., dimensionality reduction schemes for the two types of pixels. The widely-used multidimensional scaling (MDS is used for normal pixels and a new objective function, taking into account the weighting of pairwise distances, is presented for the outlier pixels. The pairwise distance weighting is designed such that small pairwise distances between the outliers and their respective neighbors are emphasized and large deviations are suppressed. This produces an image with high contrast and good interpretability while retaining the detailed information content. The proposed algorithm is compared with several state-of-the-art visualization techniques and evaluated on the well-known AVIRIS hyperspectral images. The effectiveness of the proposed strategy is substantiated both visually and quantitatively.

  18. A Two-Phase Model of Resource Allocation in Visual Working Memory

    Science.gov (United States)

    Ye, Chaoxiong; Hu, Zhonghua; Li, Hong; Ristaniemi, Tapani; Liu, Qiang; Liu, Taosheng

    2017-01-01

    Two broad theories of visual working memory (VWM) storage have emerged from current research, a discrete slot-based theory and a continuous resource theory. However, neither the discrete slot-based theory or continuous resource theory clearly stipulates how the mental commodity for VWM (discrete slot or continuous resource) is allocated.…

  19. The attention-weighted sample-size model of visual short-term memory

    DEFF Research Database (Denmark)

    Smith, Philip L.; Lilburn, Simon D.; Corbett, Elaine A.

    2016-01-01

    We investigated the capacity of visual short-term memory (VSTM) in a phase discrimination task that required judgments about the configural relations between pairs of black and white features. Sewell et al. (2014) previously showed that VSTM capacity in an orientation discrimination task was well...

  20. A dual visual-local feedback model of the vergence eye movement system

    NARCIS (Netherlands)

    Erkelens, C.J.|info:eu-repo/dai/nl/069562296

    2011-01-01

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets

  1. Usage of Data-Encoded Web Maps with Client Side Color Rendering for Combined Data Access, Visualization and Modeling Purposes

    Science.gov (United States)

    Pliutau, Denis; Prasad, Narashimha S.

    2013-01-01

    Current approaches to satellite observation data storage and distribution implement separate visualization and data access methodologies which often leads to the need in time consuming data ordering and coding for applications requiring both visual representation as well as data handling and modeling capabilities. We describe an approach we implemented for a data-encoded web map service based on storing numerical data within server map tiles and subsequent client side data manipulation and map color rendering. The approach relies on storing data using the lossless compression Portable Network Graphics (PNG) image data format which is natively supported by web-browsers allowing on-the-fly browser rendering and modification of the map tiles. The method is easy to implement using existing software libraries and has the advantage of easy client side map color modifications, as well as spatial subsetting with physical parameter range filtering. This method is demonstrated for the ASTER-GDEM elevation model and selected MODIS data products and represents an alternative to the currently used storage and data access methods. One additional benefit includes providing multiple levels of averaging due to the need in generating map tiles at varying resolutions for various map magnification levels. We suggest that such merged data and mapping approach may be a viable alternative to existing static storage and data access methods for a wide array of combined simulation, data access and visualization purposes.

  2. Influence of lateral discomfort on the stability of traffic flow based on visual angle car-following model

    Science.gov (United States)

    Zheng, Liang; Zhong, Shiquan; Jin, Peter J.; Ma, Shoufeng

    2012-12-01

    Due to the poor road markings and irregular driving behaviors, not every vehicle is positioned in the center of the lane. The deviation from the center can cause discomfort to drivers in the neighboring lane, which is referred to as lateral discomfort (or lateral friction). Such lateral discomfort can be incorporated into the driver stimulus-response framework by considering the visual angle and its changing rate from the psychological viewpoint. In this study, a two-lane visual angle based car-following model is proposed and its stability condition is obtained through linear stability theory. Further derivations indicate that the neutral stability line of the model is asymmetry and four factors including the vehicle width and length, the lateral separation and the sensitivity regarding the changing rate of visual angle have large impacts on the stability of traffic flow. Numerical simulations further verify these theoretical results, and demonstrate that the behaviors of diverging, merging and lane changing can break the original steady state and cause traffic fluctuations. However, these fluctuations may be alleviated to some extent by reducing the lateral discomfort.

  3. A Web Application For Visualizing Empirical Models of the Space-Atmosphere Interface Region: AtModWeb

    Science.gov (United States)

    Knipp, D.; Kilcommons, L. M.; Damas, M. C.

    2015-12-01

    We have created a simple and user-friendly web application to visualize output from empirical atmospheric models that describe the lower atmosphere and the Space-Atmosphere Interface Region (SAIR). The Atmospheric Model Web Explorer (AtModWeb) is a lightweight, multi-user, Python-driven application which uses standard web technology (jQuery, HTML5, CSS3) to give an in-browser interface that can produce plots of modeled quantities such as temperature and individual species and total densities of neutral and ionized upper-atmosphere. Output may be displayed as: 1) a contour plot over a map projection, 2) a pseudo-color plot (heatmap) which allows visualization of a variable as a function of two spatial coordinates, or 3) a simple line plot of one spatial coordinate versus any number of desired model output variables. The application is designed around an abstraction of an empirical atmospheric model, essentially treating the model code as a black box, which makes it simple to add additional models without modifying the main body of the application. Currently implemented are the Naval Research Laboratory NRLMSISE00 model for neutral atmosphere and the International Reference Ionosphere (IRI). These models are relevant to the Low Earth Orbit environment and the SAIR. The interface is simple and usable, allowing users (students and experts) to specify time and location, and choose between historical (i.e. the values for the given date) or manual specification of whichever solar or geomagnetic activity drivers are required by the model. We present a number of use-case examples from research and education: 1) How does atmospheric density between the surface and 1000 km vary with time of day, season and solar cycle?; 2) How do ionospheric layers change with the solar cycle?; 3 How does the composition of the SAIR vary between day and night at a fixed altitude?

  4. Bag of Visual Words Model with Deep Spatial Features for Geographical Scene Classification

    Directory of Open Access Journals (Sweden)

    Jiangfan Feng

    2017-01-01

    Full Text Available With the popular use of geotagging images, more and more research efforts have been placed on geographical scene classification. In geographical scene classification, valid spatial feature selection can significantly boost the final performance. Bag of visual words (BoVW can do well in selecting feature in geographical scene classification; nevertheless, it works effectively only if the provided feature extractor is well-matched. In this paper, we use convolutional neural networks (CNNs for optimizing proposed feature extractor, so that it can learn more suitable visual vocabularies from the geotagging images. Our approach achieves better performance than BoVW as a tool for geographical scene classification, respectively, in three datasets which contain a variety of scene categories.

  5. Bridging the gap between physiology and behavior: evidence from the sSoTS model of human visual attention.

    Science.gov (United States)

    Mavritsaki, Eirini; Heinke, Dietmar; Allen, Harriet; Deco, Gustavo; Humphreys, Glyn W

    2011-01-01

    We present the case for a role of biologically plausible neural network modeling in bridging the gap between physiology and behavior. We argue that spiking-level networks can allow "vertical" translation between physiological properties of neural systems and emergent "whole-system" performance-enabling psychological results to be simulated from implemented networks and also inferences to be made from simulations concerning processing at a neural level. These models also emphasize particular factors (e.g., the dynamics of performance in relation to real-time neuronal processing) that are not highlighted in other approaches and that can be tested empirically. We illustrate our argument from neural-level models that select stimuli by biased competition. We show that a model with biased competition dynamics can simulate data ranging from physiological studies of single-cell activity (Study 1) to whole-system behavior in human visual search (Study 2), while also capturing effects at an intermediate level, including performance breakdown after neural lesion (Study 3) and data from brain imaging (Study 4). We also show that, at each level of analysis, novel predictions can be derived from the biologically plausible parameters adopted, which we proceed to test (Study 5). We argue that, at least for studying the dynamics of visual attention, the approach productively links single-cell to psychological data.

  6. Object class recognition based on compressive sensing with sparse features inspired by hierarchical model in visual cortex

    Science.gov (United States)

    Lu, Pei; Xu, Zhiyong; Yu, Huapeng; Chang, Yongxin; Fu, Chengyu; Shao, Jianxin

    2012-11-01

    According to models of object recognition in cortex, the brain uses a hierarchical approach in which simple, low-level features having high position and scale specificity are pooled and combined into more complex, higher-level features having greater location invariance. At higher levels, spatial structure becomes implicitly encoded into the features themselves, which may overlap, while explicit spatial information is coded more coarsely. In this paper, the importance of sparsity and localized patch features in a hierarchical model inspired by visual cortex is investigated. As in the model of Serre, Wolf, and Poggio, we first apply Gabor filters at all positions and scales; feature complexity and position/scale invariance are then built up by alternating template matching and max pooling operations. In order to improve generalization performance, the sparsity is proposed and data dimension is reduced by means of compressive sensing theory and sparse representation algorithm. Similarly, within computational neuroscience, adding the sparsity on the number of feature inputs and feature selection is critical for learning biologically model from the statistics of natural images. Then, a redundancy dictionary of patch-based features that could distinguish object class from other categories is designed and then object recognition is implemented by the process of iterative optimization. The method is test on the UIUC car database. The success of this approach suggests a proof for the object class recognition in visual cortex.

  7. Declarative Visualization Queries

    Science.gov (United States)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    necessarily entirely exposed to scientists writing visualization queries, facilitates the automated construction of visualization pipelines. VisKo queries have been successfully used in support of visualization scenarios from Earth Science domains including: velocity model isosurfaces, gravity data raster, and contour map renderings. Our synergistic environment provided by our CYBER-ShARE initiative at the University of Texas at El Paso has allowed us to work closely with Earth Science experts that have both provided us our test data as well as validation as to whether the execution of VisKo queries are returning visualizations that can be used for data analysis. Additionally, we have employed VisKo queries to support visualization scenarios associated with Giovanni, an online platform for data analysis developed by NASA GES DISC. VisKo-enhanced visualizations included time series plotting of aerosol data as well as contour and raster map generation of gridded brightness-temperature data.

  8. Experimental setup for a high resolution visualization of two-phase flow in a micro-model

    Science.gov (United States)

    Karadimitriou, N. K.; Hassanizadeh, S. M.; Kleingeld, P. J.

    2009-12-01

    Flow in porous media is encountered in many industrial, biological and scientific applications. Examples of such applications are fuel cells, food production, in tissue drug delivery and micro-reactors. Despite many advantages, some major issues concerning multi-phase flow in a porous medium are not yet resolved. One characteristic example is the inadequacy of Darcy’s law. Another example is the hysteretic behavior of capillary pressure versus saturation which makes any predictive studies problematic. In the literature, theories have been developed, based on principles of mass, momentum and energy conservation and the second law of thermodynamics, which have resulted in extended Darcy’s equation and include specific interfacial area, as system variable, in addition to phase saturations and pressures. In order to investigate the significance of incorporating interfacial area as a separate variable in the governing equations of two-phase flow, an experimental setup to study and visualize two-phase flow in a micro-model under dynamic conditions was constructed. In this setup, a combination of lenses, three beam splitters and four cameras are being used to visualize flow in a two-dimensional micro-model. The micro-model will be produced using the optical lithography method and its dimensions will be 1 x 10 mm2. The shape of the pore bodies will be square. Three different realizations of the flow network will be used for mean dimension of the pore bodies equal to 6, 8.5, 14.5 μm. Through image analysis, both average saturation and average interfacial area can be determined. In our case, with the use of four cameras an area of 1 x 6.7 mm2 can be visualized, at a resolution of 0.7 μm per pixel, at any instant and the evolution of saturation and interfacial area in time and space will be determined.

  9. Bottlenecks of motion processing during a visual glance: the leaky flask model.

    Directory of Open Access Journals (Sweden)

    Haluk Öğmen

    Full Text Available Where do the bottlenecks for information and attention lie when our visual system processes incoming stimuli? The human visual system encodes the incoming stimulus and transfers its contents into three major memory systems with increasing time scales, viz., sensory (or iconic memory, visual short-term memory (VSTM, and long-term memory (LTM. It is commonly believed that the major bottleneck of information processing resides in VSTM. In contrast to this view, we show major bottlenecks for motion processing prior to VSTM. In the first experiment, we examined bottlenecks at the stimulus encoding stage through a partial-report technique by delivering the cue immediately at the end of the stimulus presentation. In the second experiment, we varied the cue delay to investigate sensory memory and VSTM. Performance decayed exponentially as a function of cue delay and we used the time-constant of the exponential-decay to demarcate sensory memory from VSTM. We then decomposed performance in terms of quality and quantity measures to analyze bottlenecks along these dimensions. In terms of the quality of information, two thirds to three quarters of the motion-processing bottleneck occurs in stimulus encoding rather than memory stages. In terms of the quantity of information, the motion-processing bottleneck is distributed, with the stimulus-encoding stage accounting for one third of the bottleneck. The bottleneck for the stimulus-encoding stage is dominated by the selection compared to the filtering function of attention. We also found that the filtering function of attention is operating mainly at the sensory memory stage in a specific manner, i.e., influencing only quantity and sparing quality. These results provide a novel and more complete understanding of information processing and storage bottlenecks for motion processing.

  10. Designing visual displays and system models for safe reactor operations based on the user`s perspective of the system

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A.

    1995-12-31

    Most designers are not schooled in the area of human-interaction psychology and therefore tend to rely on the traditional ergonomic aspects of human factors when designing complex human-interactive workstations related to reactor operations. They do not take into account the differences in user information processing behavior and how these behaviors may affect individual and team performance when accessing visual displays or utilizing system models in process and control room areas. Unfortunately, by ignoring the importance of the integration of the user interface at the information process level, the result can be sub-optimization and inherently error- and failure-prone systems. Therefore, to minimize or eliminate failures in human-interactive systems, it is essential that the designers understand how each user`s processing characteristics affects how the user gathers information, and how the user communicates the information to the designer and other users. A different type of approach in achieving this understanding is Neuro Linguistic Programming (NLP). The material presented in this paper is based on two studies involving the design of visual displays, NLP, and the user`s perspective model of a reactor system. The studies involve the methodology known as NLP, and its use in expanding design choices from the user`s ``model of the world,`` in the areas of virtual reality, workstation design, team structure, decision and learning style patterns, safety operations, pattern recognition, and much, much more.

  11. A case of impaired shape integration: Implications for models of visual object processing

    DEFF Research Database (Denmark)

    Gerlach, Christian; Marstrand, Lisbeth; Habekost, Thomas

    2005-01-01

    integration is not a prerequisite for normal object naming. However, on more demanding tests of visual object recognition, HE's performance deteriorated, with her performance being inversely related to the demand placed on integration of local elements into more elaborate shape descriptions. From this we...... conclude that shape integration is important for normal object recognition....... the notion that grouping may be divided into two general steps: (i) element clustering and (ii) shape configuration, with the latter operation being impaired in HE. As opposed to previous cases with shape integration deficits, HE was able to name objects accurately. Initially, this might suggest that shape...

  12. The role of visual similarity and memory in body model distortions.

    Science.gov (United States)

    Saulton, Aurelie; Longo, Matthew R; Wong, Hong Yu; Bülthoff, Heinrich H; de la Rosa, Stephan

    2016-02-01

    Several studies have shown that the perception of one's own hand size is distorted in proprioceptive localization tasks. It has been suggested that those distortions mirror somatosensory anisotropies. Recent research suggests that non-corporeal items also show some spatial distortions. In order to investigate the psychological processes underlying the localization task, we investigated the influences of visual similarity and memory on distortions observed on corporeal and non-corporeal items. In experiment 1, participants indicated the location of landmarks on: their own hand, a rubber hand (rated as most similar to the real hand), and a rake (rated as least similar to the real hand). Results show no significant differences between rake and rubber hand distortions but both items were significantly less distorted than the hand. Experiments 2 and 3 explored the role of memory in spatial distance judgments of the hand, the rake and the rubber hand. Spatial representations of items measured in experiments 2 and 3 were also distorted but showed the tendency to be smaller than in localization tasks. While memory and visual similarity seem to contribute to explain qualitative similarities in distortions between the hand and non-corporeal items, those factors cannot explain the larger magnitude observed in hand distortions. Copyright © 2015. Published by Elsevier B.V.

  13. Does Knowledge of Spatial Configuration in Adults with Visual Impairments Improve with Tactile Exposure to a Small-Scale Model of Their Urban Environment?

    Science.gov (United States)

    Picard, Delphine; Pry, Rene

    2009-01-01

    This study assessed the efficiency of a model of a familiar urban area for enhancing knowledge of the spatial environment by adults with visual impairments. It found a significant improvement in knowledge of spatial configuration after exposure to the model, suggesting that models are powerful means of developing cognitive mapping in people who…

  14. The Levels of Visual Framing

    Science.gov (United States)

    Rodriguez, Lulu; Dimitrova, Daniela V.

    2011-01-01

    While framing research has centered mostly on the evaluations of media texts, visual news discourse has remained relatively unexamined. This study surveys the visual framing techniques and methods employed in previous studies and proposes a four-tiered model of identifying and analyzing visual frames: (1) visuals as denotative systems, (2) visuals…

  15. Face it a visual reference for multi-ethnic facial modeling

    CERN Document Server

    Beckmann Wells, Patricia

    2013-01-01

    Face It  presents practical hands-on techniques, 3D modeling and sculpting tools with Maya and ZBrush production pipelines, uniquely focused on the facial modeling of 7 ethnicity models, featuring over 100 different models ranging in age from newborn to elderly characters. Face It is a resource for academic and professionals alike. Explore the modeling possibilities beyond the digital reference galleries online. No more having to adapt medical anatomy texts to your own models! Explore the finite details of facial anatomy with focus on skull development, muscle structure, e

  16. Methodology for the 3D modeling and visualization of concurrency networks

    Science.gov (United States)

    Dance, Linda K.; Fishwick, Paul A.

    2001-09-01

    One of the primary formalisms for modeling concurrency and resource contention in systems is Petri nets. The literature on Petri nets is rich with activity on applications as well as extensions. We use the basic Petri net formalism as well as several extensions to demonstrate how metaphor can be applied to yield 3D model worlds. A number of metaphors, including 3D-primitive and landscape are employed within the framework of VRML-enabled simulation. We designed a template for use in creating any Petri net model and then using the template, implemented an example model utilizing metaphors for both the structure and the behaviors of the model. We determined that the result is an effectively and efficiently communicated model with high memory retention. The modeling methodology that we employ was successfully implemented for Petri nets with the ability for model reuse and/or personalization with any aesthetics applied to the desired Petri net.

  17. Eye Tracking Meets the Process of Process Modeling: a Visual Analytic Approach

    DEFF Research Database (Denmark)

    Burattin, Andrea; Kaiser, M.; Neurauter, Manuel

    2017-01-01

    Research on the process of process modeling (PPM) studies how process models are created. It typically uses the logs of the interactions with the modeling tool to assess the modeler’s behavior. In this paper we suggest to introduce an additional stream of data (i.e., eye tracking) to improve the ...

  18. Expanding the Four Resources Model: Reading Visual and Multi-Modal Texts

    Science.gov (United States)

    Serafini, Frank

    2012-01-01

    Freebody and Luke proffered an expanded conceptualization of the resources readers utilize when reading and the roles readers adopt during the act of reading. The four resources model, and its associated four roles of the reader, expanded the definition of reading from a simple model of decoding printed texts to a model of constructing meaning and…

  19. Visualization of the Evolution of Layout Metrics for Business Process Models

    DEFF Research Database (Denmark)

    Haisjackl, Cornelia; Burattin, Andrea; Soffer, Pnina

    2017-01-01

    Considerable progress regarding impact factors of process model understandability has been achieved. For example, it has been shown that layout features of process models have an effect on model understandability. Even so, it appears that our knowledge about the modeler’s behavior regarding the l...

  20. Una implementación computacional de un modelo de atención visual Bottom-up aplicado a escenas naturales/A Computational Implementation of a Bottom-up Visual Attention Model Applied to Natural Scenes

    Directory of Open Access Journals (Sweden)

    Juan F. Ramírez Villegas

    2011-12-01

    Full Text Available El modelo de atención visual bottom-up propuesto por Itti et al., 2000 [1], ha sido un modelo popular en tanto exhibe cierta evidencia neurobiológica de la visión en primates. Este trabajo complementa el modelo computacional de este fenómeno desde la dinámica realista de una red neuronal. Asimismo, esta aproximación se basa en la existencia de mapas topográficos que representan la prominencia de los objetos del campo visual para la formación de una representación general (mapa de prominencia, esta representación es la entrada de una red neuronal dinámica con interacciones locales y globales de colaboración y competencia que convergen sobre las principales particularidades (objetos de la escena.The bottom-up visual attention model proposed by Itti et al. 2000 [1], has been a popular model since it exhibits certain neurobiological evidence of primates’ vision. This work complements the computational model of this phenomenon using a neural network with realistic dynamics. This approximation is based on several topographical maps representing the objects saliency that construct a general representation (saliency map, which is the input for a dynamic neural network, whose local and global collaborative and competitive interactions converge to the main particularities (objects presented by the visual scene as well.

  1. Visual Analysis of Tumor Control Models for Prediction of Radiotherapy Response

    DEFF Research Database (Denmark)

    Raidou, Renata G.; Casares Magaz, Oscar; Muren, Ludvig

    2016-01-01

    In radiotherapy, tumors are irradiated with a high dose, while surrounding healthy tissues are spared. To quantify the probability that a tumor is effectively treated with a given dose, statistical models were built and employed in clinical research. These are called tumor control probability (TCP......) models. Recently, TCP models started incor- porating additional information from imaging modalities. In this way, patient-specific properties of tumor tissues are included, improving the radiobiological accuracy of models. Yet, the employed imaging modalities are subject to uncertainties with significant...... on TCP modeling, to explore the information provided by their models, to discover new knowledge and to confirm or generate hypotheses within their data. Our approach incorporates the following four main components: (1) It supports the exploration of uncertainty and its effect on TCP models; (2...

  2. Visualization of irrigant flow and cavitation induced by Er:YAG laser within a root canal model.

    Science.gov (United States)

    Matsumoto, Himeka; Yoshimine, Yoshito; Akamine, Akifumi

    2011-06-01

    Laser-activated irrigation (LAI) has recently been introduced as an innovative method for root canal irrigation. However, there is limited information about the cleaning mechanism of an Er:YAG laser. In this study, we visualized the action of laser-induced bubbles and fluid flow in vitro to better understand the physical mechanisms underlying LAI. An Er:YAG laser was equipped with a novel cone-shaped tip with a lateral emission rate of approximately 80%. Laser light was emitted at a pulse energy of 30, 50, or 70 mJ (output energy: 11, 18, or 26 mJ) and a repetition rate of 1 or 20 pulses per second, without air or water spray. Fluid flow dynamics in a root canal model were observed by using glass-bead tracers under a high-speed camera. Moreover, laser-induced bubble patterns were visualized in both free water and the root canal model. Tracers revealed high-speed motion of the fluid. A full cycle of expansion and implosion of vapor and secondary cavitation bubbles were clearly observed. In free water, the vapor bubble expanded for 220 microseconds, and its shape resembled that of an apple. In the root canal model, the vapor bubble expanded in a vertical direction along the canal wall, and bubble expansion continued for ≥700 microseconds. Furthermore, cavitation bubbles were created much more frequently in the canal model than in free water. These results suggest that the cleaning mechanism of an Er:YAG laser within the root canal might depend on rapid fluid motion caused by expansion and implosion of laser-induced bubbles. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. GRNsight: a web application and service for visualizing models of small- to medium-scale gene regulatory networks

    Directory of Open Access Journals (Sweden)

    Kam D. Dahlquist

    2016-09-01

    Full Text Available GRNsight is a web application and service for visualizing models of gene regulatory networks (GRNs. A gene regulatory network (GRN consists of genes, transcription factors, and the regulatory connections between them which govern the level of expression of mRNA and protein from genes. The original motivation came from our efforts to perform parameter estimation and forward simulation of the dynamics of a differential equations model of a small GRN with 21 nodes and 31 edges. We wanted a quick and easy way to visualize the weight parameters from the model which represent the direction and magnitude of the influence of a transcription factor on its target gene, so we created GRNsight. GRNsight automatically lays out either an unweighted or weighted network graph based on an Excel spreadsheet containing an adjacency matrix where regulators are named in the columns and target genes in the rows, a Simple Interaction Format (SIF text file, or a GraphML XML file. When a user uploads an input file specifying an unweighted network, GRNsight automatically lays out the graph using black lines and pointed arrowheads. For a weighted network, GRNsight uses pointed and blunt arrowheads, and colors the edges and adjusts their thicknesses based on the sign (positive for activation or negative for repression and magnitude of the weight parameter. GRNsight is written in JavaScript, with diagrams facilitated by D3.js, a data visualization library. Node.js and the Express framework handle server-side functions. GRNsight’s diagrams are based on D3.js’s force graph layout algorithm, which was then extensively customized to support the specific needs of GRNs. Nodes are rectangular and support gene labels of up to 12 characters. The edges are arcs, which become straight lines when the nodes are close together. Self-regulatory edges are indicated by a loop. When a user mouses over an edge, the numerical value of the weight parameter is displayed. Visualizations can

  4. Influence of bushenhuoxue on primary visual cortex' BDNF damage in rat model of chronic elevated intraocular pressure

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2013-04-01

    Full Text Available AIM: To observe the effect of traditional Chinese medicine(TCMof bushenhuoxue on primary visual cortex(PVCbrain-derived neurotrophic factor(BDNFin rat model of chronic elevated intraocular pressure(EIOP, and explore the mechanism of it initially. METHODS: The rat model of chronic EIOP was established by unilaterally cauterizing 3 episcleral veins, then 30 rats were divided into 3 groups randomly: control group, model group, and treatment group. After given drugs or normal saline for 8 weeks, the rats were put to death. The effect of intraocular pressure(IOP, expression of BDNF and ultrastructure of neuron cell in the PVC was observed. RESULTS: Unilaterally cauterizing episcleral veins increased IOP of the rat model obviously, there was significant difference compared with pre-operation(P<0.01. Semi-quantitative pathological analysis on PVC showed that BDNF of total area in the model group was(82438±2597.39S/μm2,mean optical density was(1155.9±123.14, integrated optical density was(12915±673.28, compared with the control group {total area was(132370±7588.47S/μm2, mean optical density was(5365±379.65, integrated optical density was(35102±2648.5}, there were statistical differences(all P<0.05,there was statistical difference in BDNF of total area between model group and treatment group{(108980±9126.77S/μm2, P<0.05}, significant difference in mean optical density between the model group and treatment group(3220.4±413.67, P<0.05, statistical difference in integrated optical density between the model group and treatment group(23821±3431.68, P<0.05. CONCLUSION: TCM of bushenhuoxue can repair the PVC damage in the rat model of chronic EIOP by enhancing expression of BDNF, improving ultrastructure of neuron cell.

  5. Fine reservoir structure modeling based upon 3D visualized stratigraphic correlation between horizontal wells: methodology and its application

    Science.gov (United States)

    Chenghua, Ou; Chaochun, Li; Siyuan, Huang; Sheng, James J.; Yuan, Xu

    2017-12-01

    As the platform-based horizontal well production mode has been widely applied in petroleum industry, building a reliable fine reservoir structure model by using horizontal well stratigraphic correlation has become very important. Horizontal wells usually extend between the upper and bottom boundaries of the target formation, with limited penetration points. Using these limited penetration points to conduct well deviation correction means the formation depth information obtained is not accurate, which makes it hard to build a fine structure model. In order to solve this problem, a method of fine reservoir structure modeling, based on 3D visualized stratigraphic correlation among horizontal wells, is proposed. This method can increase the accuracy when estimating the depth of the penetration points, and can also effectively predict the top and bottom interfaces in the horizontal penetrating section. Moreover, this method will greatly increase not only the number of points of depth data available, but also the accuracy of these data, which achieves the goal of building a reliable fine reservoir structure model by using the stratigraphic correlation among horizontal wells. Using this method, four 3D fine structure layer models have been successfully built of a specimen shale gas field with platform-based horizontal well production mode. The shale gas field is located to the east of Sichuan Basin, China; the successful application of the method has proven its feasibility and reliability.

  6. Development of a computational model on the neural activity patterns of a visual working memory in a hierarchical feedforward Network

    Science.gov (United States)

    An, Soyoung; Choi, Woochul; Paik, Se-Bum

    2015-11-01

    Understanding the mechanism of information processing in the human brain remains a unique challenge because the nonlinear interactions between the neurons in the network are extremely complex and because controlling every relevant parameter during an experiment is difficult. Therefore, a simulation using simplified computational models may be an effective approach. In the present study, we developed a general model of neural networks that can simulate nonlinear activity patterns in the hierarchical structure of a neural network system. To test our model, we first examined whether our simulation could match the previously-observed nonlinear features of neural activity patterns. Next, we performed a psychophysics experiment for a simple visual working memory task to evaluate whether the model could predict the performance of human subjects. Our studies show that the model is capable of reproducing the relationship between memory load and performance and may contribute, in part, to our understanding of how the structure of neural circuits can determine the nonlinear neural activity patterns in the human brain.

  7. Development of Children's Creative Visual Imagination: A Theoretical Model and Enhancement Programmes

    Science.gov (United States)

    Dziedziewicz, Dorota; Karwowski, Maciej

    2015-01-01

    This paper presents a new theoretical model of creative imagination and its applications in early education. The model sees creative imagination as composed of three inter-related components: vividness of images, their originality, and the level of transformation of imageries. We explore the theoretical and practical consequences of this new…

  8. Stakeholder approach, Stakeholders mental model: A visualization test with cognitive mapping technique

    OpenAIRE

    Garoui Nassreddine; Jarboui Anis

    2012-01-01

    The idea of this paper is to determine the mental models of actors in the firm with respect to the stakeholder approach of corporate governance. The use of the cognitive map to view these diagrams to show the ways of thinking and conceptualization of the stakeholder approach. The paper takes a corporate governance perspective, discusses stakeholder model. It takes also a cognitive mapping technique.

  9. Visual representations of the idealized cognitive model of anger in the Asterix album 'La Zizanie'

    NARCIS (Netherlands)

    Forceville, C.

    2005-01-01

    The conceptual metaphor program launched by Lakoff and Johnson [Metaphors We Live By, Chicago, University of Chicago Press, 1980] attempts to chart and describe the Idealized Cognitive Models (ICMs) that govern human thinking. The manifestations of these models studied hitherto, however, are almost

  10. Can Centre Surround Model Explain the Enhancement of Visual Perception through Stochastic Resonance?

    CERN Document Server

    Kundu, Ajanta

    2010-01-01

    We demonstrate the ability of centre surround model for simulating the enhancement of contrast sensitivity through stochastic resonance observed in psychophysical experiments. We also show that this model could be used to simulate the contrast sensitivity function through stochastic resonance. The quality of the fit of measured contrast sensitivity function to the simulated data is very good.

  11. Visualizing the structure of RNA-seq expression data using grade of membership models.

    Directory of Open Access Journals (Sweden)

    Kushal K Dey

    2017-03-01

    Full Text Available Grade of membership models, also known as "admixture models", "topic models" or "Latent Dirichlet Allocation", are a generalization of cluster models that allow each sample to have membership in multiple clusters. These models are widely used in population genetics to model admixed individuals who have ancestry from multiple "populations", and in natural language processing to model documents having words from multiple "topics". Here we illustrate the potential for these models to cluster samples of RNA-seq gene expression data, measured on either bulk samples or single cells. We also provide methods to help interpret the clusters, by identifying genes that are distinctively expressed in each cluster. By applying these methods to several example RNA-seq applications we demonstrate their utility in identifying and summarizing structure and heterogeneity. Applied to data from the GTEx project on 53 human tissues, the approach highlights similarities among biologically-related tissues and identifies distinctively-expressed genes that recapitulate known biology. Applied to single-cell expression data from mouse preimplantation embryos, the approach highlights both discrete and continuous variation through early embryonic development stages, and highlights genes involved in a variety of relevant processes-from germ cell development, through compaction and morula formation, to the formation of inner cell mass and trophoblast at the blastocyst stage. The methods are implemented in the Bioconductor package CountClust.

  12. Modeling and Visualizing Uncertainty in Continuous Variables Predicted using Remotely Sensed Data

    Science.gov (United States)

    Dungan, Jennifer L.; Kao, David L.; Pang, Alex

    2003-01-01

    The use of remotely sensed images to map continuous biophysical variables, such as those related to terrestrial vegetation amount, sea surface temperature, and many other targets of NASA s Earth Observing System (EOS), includes variable, parametric, positional, spatial support and structural sources of uncertainty. A complete description of uncertainty will lead to a probability distribution at each location, allowing the exploration of the spatial dimension of uncertainty, that is, where the field is not well quantified. To achieve this purpose, convenient visualization tools are required. We have produced such a tool, called PDFVis, that facilitates the display of probability density functions (pdfs) on a per-grid-cell basis. The density estimate from Monte-Carlo generated realizations is interactively displayed as well as parametric and non-parametric summaries of the pdf field (such as mean, median, quartiles, standard deviation, number of modes, and locations of modes). Shaded surface renderings of pdfs along a transect can also be projected onto a plane. This tool will become more useful as richer descriptions of spatial uncertainty become available.

  13. Mantisbot is a robotic model of visually guided motion in the praying mantis.

    Science.gov (United States)

    Szczecinski, Nicholas S; Getsy, Andrew P; Martin, Joshua P; Ritzmann, Roy E; Quinn, Roger D

    2017-09-01

    Insects use highly distributed nervous systems to process exteroception from head sensors, compare that information with state-based goals, and direct posture or locomotion toward those goals. To study how descending commands from brain centers produce coordinated, goal-directed motion in distributed nervous systems, we have constructed a conductance-based neural system for our robot MantisBot, a 29 degree-of-freedom, 13.3:1 scale praying mantis robot. Using the literature on mantis prey tracking and insect locomotion, we designed a hierarchical, distributed neural controller that establishes the goal, coordinates different joints, and executes prey-tracking motion. In our controller, brain networks perceive the location of prey and predict its future location, store this location in memory, and formulate descending commands for ballistic saccades like those seen in the animal. The descending commands are simple, indicating only 1) whether the robot should walk or stand still, and 2) the intended direction of motion. Each joint's controller uses the descending commands differently to alter sensory-motor interactions, changing the sensory pathways that coordinate the joints' central pattern generators into one cohesive motion. Experiments with one leg of MantisBot show that visual input produces simple descending commands that alter walking kinematics, change the walking direction in a predictable manner, enact reflex reversals when necessary, and can control both static posture and locomotion with the same network. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Gas discharge visualization: an imaging and modeling tool for medical biometrics.

    Science.gov (United States)

    Kostyuk, Nataliya; Cole, Phyadragren; Meghanathan, Natarajan; Isokpehi, Raphael D; Cohly, Hari H P

    2011-01-01

    The need for automated identification of a disease makes the issue of medical biometrics very current in our society. Not all biometric tools available provide real-time feedback. We introduce gas discharge visualization (GDV) technique as one of the biometric tools that have the potential to identify deviations from the normal functional state at early stages and in real time. GDV is a nonintrusive technique to capture the physiological and psychoemotional status of a person and the functional status of different organs and organ systems through the electrophotonic emissions of fingertips placed on the surface of an impulse analyzer. This paper first introduces biometrics and its different types and then specifically focuses on medical biometrics and the potential applications of GDV in medical biometrics. We also present our previous experience with GDV in the research regarding autism and the potential use of GDV in combination with computer science for the potential development of biological pattern/biomarker for different kinds of health abnormalities including cancer and mental diseases.

  15. Gas Discharge Visualization: An Imaging and Modeling Tool for Medical Biometrics

    Directory of Open Access Journals (Sweden)

    Nataliya Kostyuk

    2011-01-01

    Full Text Available The need for automated identification of a disease makes the issue of medical biometrics very current in our society. Not all biometric tools available provide real-time feedback. We introduce gas discharge visualization (GDV technique as one of the biometric tools that have the potential to identify deviations from the normal functional state at early stages and in real time. GDV is a nonintrusive technique to capture the physiological and psychoemotional status of a person and the functional status of different organs and organ systems through the electrophotonic emissions of fingertips placed on the surface of an impulse analyzer. This paper first introduces biometrics and its different types and then specifically focuses on medical biometrics and the potential applications of GDV in medical biometrics. We also present our previous experience with GDV in the research regarding autism and the potential use of GDV in combination with computer science for the potential development of biological pattern/biomarker for different kinds of health abnormalities including cancer and mental diseases.

  16. Visualizing the Effects of Sputum on Biofilm Development Using a Chambered Coverglass Model.

    Science.gov (United States)

    Beaudoin, Trevor; Kennedy, Sarah; Yau, Yvonne; Waters, Valerie

    2016-12-14

    Biofilms consist of groups of bacteria encased in a self-secreted matrix. They play an important role in industrial contamination as well as in the development and persistence of many health related infections. One of the most well described and studied biofilms in human disease occurs in chronic pulmonary infection of cystic fibrosis patients. When studying biofilms in the context of the host, many factors can impact biofilm formation and development. In order to identify how host factors may affect biofilm formation and development, we used a static chambered coverglass method to grow biofilms in the presence of host-derived factors in the form of sputum supernatants. Bacteria are seeded into chambers and exposed to sputum filtrates. Following 48 hr of growth, biofilms are stained with a commercial biofilm viability kit prior to confocal microscopy and analysis. Following image acquisition, biofilm properties can be assessed using different software platforms. This method allows us to visualize key properties of biofilm growth in presence of different substances including antibiotics.

  17. Endolymph movement visualized with light sheet fluorescence microscopy in an acute hydrops model.

    Science.gov (United States)

    Brown, Daniel J; Pastras, Christopher J; Curthoys, Ian S; Southwell, Cassandra S; Van Roon, Lieke

    2016-09-01

    There are a variety of techniques available to investigate endolymph dynamics, primarily seeking to understand the cause of endolymphatic hydrops. Here we have taken the novel approach of injecting, via a glass micropipette, fluorescein isothiocyanate-dextran (FITC-dex) and artificial endolymph into scala media of anaesthetized guinea pigs, with subsequent imaging of the inner ear using Light Sheet Fluorescence Microscopy (LSFM) as a means to obtain highly resolved 3D visualization of fluid movements. Our results demonstrate endolymph movement into the utricle, semicircular canals and endolymphatic duct and sac when more than 2.5 μl of fluid had been injected into scala media, with no apparent movement of fluid into the perilymphatic compartments. There was no movement of endolymph into these compartments when less than 2.5 μl was injected. The remarkable uptake of the FITC-dex into the endolymphatic duct, including an absorption into the periductal channels surrounding the endolymphatic duct, highlights the functional role this structure plays in endolymph volume regulation. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  18. Unsupervised Gaussian Mixture-Model With Expectation Maximization for Detecting Glaucomatous Progression in Standard Automated Perimetry Visual Fields.

    Science.gov (United States)

    Yousefi, Siamak; Balasubramanian, Madhusudhanan; Goldbaum, Michael H; Medeiros, Felipe A; Zangwill, Linda M; Weinreb, Robert N; Liebmann, Jeffrey M; Girkin, Christopher A; Bowd, Christopher

    2016-05-01

    To validate Gaussian mixture-model with expectation maximization (GEM) and variational Bayesian independent component analysis mixture-models (VIM) for detecting glaucomatous progression along visual field (VF) defect patterns (GEM-progression of patterns (POP) and VIM-POP). To compare GEM-POP and VIM-POP with other methods. GEM and VIM models separated cross-sectional abnormal VFs from 859 eyes and normal VFs from 1117 eyes into abnormal and normal clusters. Clusters were decomposed into independent axes. The confidence limit (CL) of stability was established for each axis with a set of 84 stable eyes. Sensitivity for detecting progression was assessed in a sample of 83 eyes with known progressive glaucomatous optic neuropathy (PGON). Eyes were classified as progressed if any defect pattern progressed beyond the CL of stability. Performance of GEM-POP and VIM-POP was compared to point-wise linear regression (PLR), permutation analysis of PLR (PoPLR), and linear regression (LR) of mean deviation (MD), and visual field index (VFI). Sensitivity and specificity for detecting glaucomatous VFs were 89.9% and 93.8%, respectively, for GEM and 93.0% and 97.0%, respectively, for VIM. Receiver operating characteristic (ROC) curve areas for classifying progressed eyes were 0.82 for VIM-POP, 0.86 for GEM-POP, 0.81 for PoPLR, 0.69 for LR of MD, and 0.76 for LR of VFI. GEM-POP was significantly more sensitive to PGON than PoPLR and linear regression of MD and VFI in our sample, while providing localized progression information. Detection of glaucomatous progression can be improved by assessing longitudinal changes in localized patterns of glaucomatous defect identified by unsupervised machine learning.

  19. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  20. Musculoskeletal-see-through mirror: computational modeling and algorithm for whole-body muscle activity visualization in real time.

    Science.gov (United States)

    Murai, Akihiko; Kurosaki, Kosuke; Yamane, Katsu; Nakamura, Yoshihiko

    2010-12-01

    In this paper, we present a system that estimates and visualizes muscle tensions in real time using optical motion capture and electromyography (EMG). The system overlays rendered musculoskeletal human model on top of a live video image of the subject. The subject therefore has an impression that he/she sees the muscles with tension information through the cloth and skin. The main technical challenge lies in real-time estimation of muscle tension. Since existing algorithms using mathematical optimization to distribute joint torques to muscle tensions are too slow for our purpose, we develop a new algorithm that computes a reasonable approximation of muscle tensions based on the internal connections between muscles known as neuronal binding. The algorithm can estimate the tensions of 274 muscles in only 16 ms, and the whole visualization system runs at about 15 fps. The developed system is applied to assisting sport training, and the user case studies show its usefulness. Possible applications include interfaces for assisting rehabilitation. Copyright © 2010 Elsevier Ltd. All rights reserved.