Science.gov

Sample records for adaptive visual analytics

  1. Guided Text Analysis Using Adaptive Visual Analytics

    SciTech Connect

    Steed, Chad A; Symons, Christopher T; DeNap, Frank A; Potok, Thomas E; Potok, Thomas E

    2012-01-01

    This paper demonstrates the promise of augmenting interactive visualizations with semi-supervised machine learning techniques to improve the discovery of significant associations and insight in the search and analysis of textual information. More specifically, we have developed a system called Gryffin that hosts a unique collection of techniques that facilitate individualized investigative search pertaining to an ever-changing set of analytical questions over an indexed collection of open-source publications related to national infrastructure. The Gryffin client hosts dynamic displays of the search results via focus+context record listings, temporal timelines, term- frequency views, and multiple coordinated views. Furthermore, as the analyst interacts with the display, the interactions are recorded and used to label the search records. These labeled records are then used to drive semi-supervised machine learning algorithms that re-rank the unlabeled search records such that potentially relevant records are moved to the top of the record listing. Gryffin is described in the context of the daily tasks encountered at the Department of Homeland Securitys Fusion Centers, with whom we are collaborating in its development. The resulting system is capable of addressing the analysts information overload that can be directly attributed to the deluge of information that must be addressed in search and investigative analysis of textual information.

  2. Guided text analysis using adaptive visual analytics

    NASA Astrophysics Data System (ADS)

    Steed, Chad A.; Symons, Christopher T.; DeNap, Frank A.; Potok, Thomas E.

    2012-01-01

    This paper demonstrates the promise of augmenting interactive visualizations with semi-supervised machine learning techniques to improve the discovery of significant associations and insight in the search and analysis of textual information. More specifically, we have developed a system-called Gryffin-that hosts a unique collection of techniques that facilitate individualized investigative search pertaining to an ever-changing set of analytical questions over an indexed collection of open-source publications related to national infrastructure. The Gryffin client hosts dynamic displays of the search results via focus+context record listings, temporal timelines, term-frequency views, and multiple coordinated views. Furthermore, as the analyst interacts with the display, the interactions are recorded and used to label the search records. These labeled records are then used to drive semi-supervised machine learning algorithms that re-rank the unlabeled search records such that potentially relevant records are moved to the top of the record listing. Gryffin is described in the context of the daily tasks encountered at the Department of Homeland Security's Fusion Centers, with whom we are collaborating in its development. The resulting system is capable of addressing the analysts information overload that can be directly attributed to the deluge of information that must be addressed in search and investigative analysis of textual information.

  3. Guided Text Search Using Adaptive Visual Analytics

    SciTech Connect

    Steed, Chad A; Symons, Christopher T; Senter, James K; DeNap, Frank A

    2012-10-01

    This research demonstrates the promise of augmenting interactive visualizations with semi- supervised machine learning techniques to improve the discovery of significant associations and insights in the search and analysis of textual information. More specifically, we have developed a system called Gryffin that hosts a unique collection of techniques that facilitate individualized investigative search pertaining to an ever-changing set of analytical questions over an indexed collection of open-source documents related to critical national infrastructure. The Gryffin client hosts dynamic displays of the search results via focus+context record listings, temporal timelines, term-frequency views, and multiple coordinate views. Furthermore, as the analyst interacts with the display, the interactions are recorded and used to label the search records. These labeled records are then used to drive semi-supervised machine learning algorithms that re-rank the unlabeled search records such that potentially relevant records are moved to the top of the record listing. Gryffin is described in the context of the daily tasks encountered at the US Department of Homeland Security s Fusion Center, with whom we are collaborating in its development. The resulting system is capable of addressing the analysts information overload that can be directly attributed to the deluge of information that must be addressed in the search and investigative analysis of textual information.

  4. InfoStar : an adaptive visual analytics platform for mobile devices.

    SciTech Connect

    Gatchell, Doug; Borchers, Bob; Schrager, Matthew A.; Thornton, Susan; Collins, Sharon; Van Randwyk, Jamie A.; Danielson, Gary; Riensche, Rick; May, Richard; Baddeley, Bob; Sanfilippo, Antonio; Washington, Kenneth Edward

    2005-03-01

    We present the design and implementation of InfoStar, an adaptive Visual Analytics platform for mobile devices such a PDAs, laptops, Tablet PCs and mobile phones. InfoStar extends the reach of visual analytics technology beyond the traditional desktop paradigm to provide ubiquitous access to inter-active visualizations of information spaces. These visualizations are critical in addressing the knowledge needs of human agents operating in the field, in areas as diverse as business, homeland security, law enforcement, protective services, emergency medical services and scientific discovery. We describe an initial real world deployment of this technology, in which the InfoStar platform has been used to offer mobile access to scheduling and venue information to conference attendees at Supercomputing 2004.

  5. InfoStar: An Adaptive Visual Analytics Platform for Mobile Devices

    SciTech Connect

    Sanfilippo, Antonio P.; May, Richard A.; Danielson, Gary R.; Baddeley, Bob L.; Riensche, Roderick M.; Collins, Sharon; Thornton, Susan E.; Washington, Kenneth; Schrager, Matt; Van Randwyk, Jamie; Borchers, Bob; Gatchell, Doug

    2005-05-09

    We present the design and implementation of InfoStar, an adaptive Visual Analytics platform for mobile devices such a PDAs, laptops, Tablet PCs and mobile phones. InfoStar extends the reach of visual analytics technology beyond the traditional desktop paradigm to provide ubiquitous access to inter-active visualizations of information spaces. These visualizations are critical in addressing the knowledge needs of human agents operating in the field, in areas as diverse as business, homeland security, law enforcement, protective services, emergency medical services and scientific discovery. We describe an initial real world deployment of this technology, in which the InfoStar platform has been used to offer mobile access to scheduling and venue information to conference attendees at Supercomputing 2004.

  6. Visual Analytics Technology Transition Progress

    SciTech Connect

    Scholtz, Jean; Cook, Kristin A.; Whiting, Mark A.; Lemon, Douglas K.; Greenblatt, Howard

    2009-09-23

    The authors provide a description of the transition process for visual analytic tools and contrast this with the transition process for more traditional software tools. This paper takes this into account and describes a user-oriented approach to technology transition including a discussion of key factors that should be considered and adapted to each situation. The progress made in transitioning visual analytic tools in the past five years is described and the challenges that remain are enumerated.

  7. Extreme Scale Visual Analytics

    SciTech Connect

    Steed, Chad A; Potok, Thomas E; Pullum, Laura L; Ramanathan, Arvind; Shipman, Galen M; Thornton, Peter E; Potok, Thomas E

    2013-01-01

    Given the scale and complexity of today s data, visual analytics is rapidly becoming a necessity rather than an option for comprehensive exploratory analysis. In this paper, we provide an overview of three applications of visual analytics for addressing the challenges of analyzing climate, text streams, and biosurveilance data. These systems feature varying levels of interaction and high performance computing technology integration to permit exploratory analysis of large and complex data of global significance.

  8. Extreme Scale Visual Analytics

    SciTech Connect

    Wong, Pak C.; Shen, Han-Wei; Pascucci, Valerio

    2012-05-08

    Extreme-scale visual analytics (VA) is about applying VA to extreme-scale data. The articles in this special issue examine advances related to extreme-scale VA problems, their analytical and computational challenges, and their real-world applications.

  9. Challenges for Visual Analytics

    SciTech Connect

    Thomas, James J.; Kielman, Joseph

    2009-09-23

    Visual analytics has seen unprecedented growth in its first five years of mainstream existence. Great progress has been made in a short time, yet great challenges must be met in the next decade to provide new technologies that will be widely accepted by societies throughout the world. This paper sets the stage for some of those challenges in an effort to provide the stimulus for the research, both basic and applied, to address and exceed the envisioned potential for visual analytics technologies. We start with a brief summary of the initial challenges, followed by a discussion of the initial driving domains and applications, as well as additional applications and domains that have been a part of recent rapid expansion of visual analytics usage. We look at the common characteristics of several tools illustrating emerging visual analytics technologies, and conclude with the top ten challenges for the field of study. We encourage feedback and collaborative participation by members of the research community, the wide array of user communities, and private industry.

  10. Visual Analytics: How Much Visualization and How Much Analytics?

    SciTech Connect

    Keim, Daniel; Mansmann, Florian; Thomas, James J.

    2009-12-16

    The term Visual Analytics has been around for almost five years by now, but still there are on-going discussions about what it actually is and in particular what is new about it. The core of our view on Visual Analytics is the new enabling and accessible analytic reasoning interactions supported by the combination of automated and visual analytics. In this paper, we outline the scope of Visual Analytics using two problem and three methodological classes in order to work out the need for and purpose of Visual Analytics. Thereby, the respective methods are explained plus examples of analytic reasoning interaction leading to a glimpse into the future of how Visual Analytics methods will enable us to go beyond what is possible when separately using the two methods.

  11. Multimedia Analysis plus Visual Analytics = Multimedia Analytics

    SciTech Connect

    Chinchor, Nancy; Thomas, James J.; Wong, Pak C.; Christel, Michael; Ribarsky, Martin W.

    2010-10-01

    Multimedia analysis has focused on images, video, and to some extent audio and has made progress in single channels excluding text. Visual analytics has focused on the user interaction with data during the analytic process plus the fundamental mathematics and has continued to treat text as did its precursor, information visualization. The general problem we address in this tutorial is the combining of multimedia analysis and visual analytics to deal with multimedia information gathered from different sources, with different goals or objectives, and containing all media types and combinations in common usage.

  12. Adaptation and visual coding

    PubMed Central

    Webster, Michael A.

    2011-01-01

    Visual coding is a highly dynamic process and continuously adapting to the current viewing context. The perceptual changes that result from adaptation to recently viewed stimuli remain a powerful and popular tool for analyzing sensory mechanisms and plasticity. Over the last decade, the footprints of this adaptation have been tracked to both higher and lower levels of the visual pathway and over a wider range of timescales, revealing that visual processing is much more adaptable than previously thought. This work has also revealed that the pattern of aftereffects is similar across many stimulus dimensions, pointing to common coding principles in which adaptation plays a central role. However, why visual coding adapts has yet to be fully answered. PMID:21602298

  13. VA²: A Visual Analytics Approach for // Evaluating Visual Analytics Applications.

    PubMed

    Blascheck, Tanja; John, Markus; Kurzhals, Kuno; Koch, Steffen; Ertl, Thomas

    2016-01-01

    Evaluation has become a fundamental part of visualization research and researchers have employed many approaches from the field of human-computer interaction like measures of task performance, thinking aloud protocols, and analysis of interaction logs. Recently, eye tracking has also become popular to analyze visual strategies of users in this context. This has added another modality and more data, which requires special visualization techniques to analyze this data. However, only few approaches exist that aim at an integrated analysis of multiple concurrent evaluation procedures. The variety, complexity, and sheer amount of such coupled multi-source data streams require a visual analytics approach. Our approach provides a highly interactive visualization environment to display and analyze thinking aloud, interaction, and eye movement data in close relation. Automatic pattern finding algorithms allow an efficient exploratory search and support the reasoning process to derive common eye-interaction-thinking patterns between participants. In addition, our tool equips researchers with mechanisms for searching and verifying expected usage patterns. We apply our approach to a user study involving a visual analytics application and we discuss insights gained from this joint analysis. We anticipate our approach to be applicable to other combinations of evaluation techniques and a broad class of visualization applications.

  14. A Visual Analytics Agenda

    SciTech Connect

    Thomas, James J.; Cook, Kristin A.

    2006-01-01

    The September 11, 2001 attacks on the World Trade Center and the Pentagon were a wakeup call to the United States. The Hurricane Katrina disaster in August 2005 provided yet another reminder that unprecedented disasters can and do occur. And when they do, we must be able to analyze large amounts of disparate data in order to make sense of exceedingly complex situations and save lives. Responding to an Urgent Need This need to support penetrating analysis of massive data collections is not limited to security, though. From systems biology to human health, from evaluations of product effectiveness to strategizing for competitive positioning, to assessing the results of marketing campaigns, there is a critical need to analyze very large amounts of complex information. Simply put, our ability to collect data far outstrips our ability to analyze the data we have collected. Following the September 11 attacks, the government initiated efforts to evaluate the technologies that are available today or are on the near horizon. Two National Academy of Sciences reports identified serious gaps in the technologies. Making the Nation Safer [Alberts & Wulf, 2002] describes how science and technology can be advanced to protect the nation against terrorism. Information Technology for Counterterrorism [Hennessy et al., 2003] expands upon the work of Making the Nation Safer, focusing specifically on the opportunities for information technology to help counter and respond to terrorist attacks. Significant research progress has been made in disciplines such as scientific and information visualization, statistically-based exploratory and confirmatory analysis, data and knowledge representations, and perceptual and cognitive sciences, However, the research community has not adequately addressed the integration of these subspecialties to advance the ability for analysts to apply their expert human judgment to complex data in pressure-filled situations. Although some research is being done

  15. Visual analytics of brain networks.

    PubMed

    Li, Kaiming; Guo, Lei; Faraco, Carlos; Zhu, Dajiang; Chen, Hanbo; Yuan, Yixuan; Lv, Jinglei; Deng, Fan; Jiang, Xi; Zhang, Tuo; Hu, Xintao; Zhang, Degang; Miller, L Stephen; Liu, Tianming

    2012-05-15

    Identification of regions of interest (ROIs) is a fundamental issue in brain network construction and analysis. Recent studies demonstrate that multimodal neuroimaging approaches and joint analysis strategies are crucial for accurate, reliable and individualized identification of brain ROIs. In this paper, we present a novel approach of visual analytics and its open-source software for ROI definition and brain network construction. By combining neuroscience knowledge and computational intelligence capabilities, visual analytics can generate accurate, reliable and individualized ROIs for brain networks via joint modeling of multimodal neuroimaging data and an intuitive and real-time visual analytics interface. Furthermore, it can be used as a functional ROI optimization and prediction solution when fMRI data is unavailable or inadequate. We have applied this approach to an operation span working memory fMRI/DTI dataset, a schizophrenia DTI/resting state fMRI (R-fMRI) dataset, and a mild cognitive impairment DTI/R-fMRI dataset, in order to demonstrate the effectiveness of visual analytics. Our experimental results are encouraging.

  16. Visual Analytics of Brain Networks

    PubMed Central

    Li, Kaiming; Guo, Lei; Faraco, Carlos; Zhu, Dajiang; Chen, Hanbo; Yuan, Yixuan; Lv, Jinglei; Deng, Fan; Jiang, Xi; Zhang, Tuo; Hu, Xintao; Zhang, Degang; Miller, L Stephen; Liu, Tianming

    2014-01-01

    Identification of regions of interest (ROIs) is a fundamental issue in brain network construction and analysis. Recent studies demonstrate that multimodal neuroimaging approaches and joint analysis strategies are crucial for accurate, reliable and individualized identification of brain ROIs. In this paper, we present a novel approach of visual analytics and its open-source software for ROI definition and brain network construction. By combining neuroscience knowledge and computational intelligence capabilities, visual analytics can generate accurate, reliable and individualized ROIs for brain networks via joint modeling of multimodal neuroimaging data and an intuitive and real-time visual analytics interface. Furthermore, it can be used as a functional ROI optimization and prediction solution when fMRI data is unavailable or inadequate. We have applied this approach to an operation span working memory fMRI/DTI dataset, a schizophrenia DTI/resting state fMRI (R-fMRI) dataset, and a mild cognitive impairment DTI/R-fMRI dataset, in order to demonstrate the effectiveness of visual analytics. Our experimental results are encouraging. PMID:22414991

  17. Personal Visualization and Personal Visual Analytics.

    PubMed

    Huang, Dandan; Tory, Melanie; Aseniero, Bon Adriel; Bartram, Lyn; Bateman, Scott; Carpendale, Sheelagh; Tang, Anthony; Woodbury, Robert

    2015-03-01

    Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research directions required to take full advantage of Vis and VA in a personal context. We develop a taxonomy of design dimensions to provide a coherent vocabulary for discussing personal visualization and personal visual analytics. By identifying and exploring clusters in the design space, we discuss challenges and share perspectives on future research. This work brings together research that was previously scattered across disciplines. Our goal is to call research attention to this space and engage researchers to explore the enabling techniques and technology that will support people to better understand data relevant to their personal lives, interests, and needs.

  18. Personal Visualization and Personal Visual Analytics.

    PubMed

    Huang, Dandan; Tory, Melanie; Aseniero, Bon Adriel; Bartram, Lyn; Bateman, Scott; Carpendale, Sheelagh; Tang, Anthony; Woodbury, Robert

    2015-03-01

    Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research directions required to take full advantage of Vis and VA in a personal context. We develop a taxonomy of design dimensions to provide a coherent vocabulary for discussing personal visualization and personal visual analytics. By identifying and exploring clusters in the design space, we discuss challenges and share perspectives on future research. This work brings together research that was previously scattered across disciplines. Our goal is to call research attention to this space and engage researchers to explore the enabling techniques and technology that will support people to better understand data relevant to their personal lives, interests, and needs. PMID:26357073

  19. Visual Analytics for MOOC Data.

    PubMed

    Qu, Huamin; Chen, Qing

    2015-01-01

    With the rise of massive open online courses (MOOCs), tens of millions of learners can now enroll in more than 1,000 courses via MOOC platforms such as Coursera and edX. As a result, a huge amount of data has been collected. Compared with traditional education records, the data from MOOCs has much finer granularity and also contains new pieces of information. It is the first time in history that such comprehensive data related to learning behavior has become available for analysis. What roles can visual analytics play in this MOOC movement? The authors survey the current practice and argue that MOOCs provide an opportunity for visualization researchers and that visual analytics systems for MOOCs can benefit a range of end users such as course instructors, education researchers, students, university administrators, and MOOC providers. PMID:26594957

  20. Visual Analytics for MOOC Data.

    PubMed

    Qu, Huamin; Chen, Qing

    2015-01-01

    With the rise of massive open online courses (MOOCs), tens of millions of learners can now enroll in more than 1,000 courses via MOOC platforms such as Coursera and edX. As a result, a huge amount of data has been collected. Compared with traditional education records, the data from MOOCs has much finer granularity and also contains new pieces of information. It is the first time in history that such comprehensive data related to learning behavior has become available for analysis. What roles can visual analytics play in this MOOC movement? The authors survey the current practice and argue that MOOCs provide an opportunity for visualization researchers and that visual analytics systems for MOOCs can benefit a range of end users such as course instructors, education researchers, students, university administrators, and MOOC providers.

  1. Visual adaptation dominates bimodal visual-motor action adaptation

    PubMed Central

    de la Rosa, Stephan; Ferstl, Ylva; Bülthoff, Heinrich H.

    2016-01-01

    A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for understanding action recognition in social interactions, where humans often observe and execute actions at the same time. Here, we behaviourally examined the interaction of visual and motor action recognition processes when participants simultaneously observe and execute actions. We took advantage of behavioural action adaptation effects to investigate behavioural correlates of neural action recognition mechanisms. In line with previous results, we find that prolonged visual exposure (visual adaptation) and prolonged execution of the same action with closed eyes (non-visual motor adaptation) influence action recognition. However, when participants simultaneously adapted visually and motorically – akin to simultaneous execution and observation of actions in social interactions - adaptation effects were only modulated by visual but not motor adaptation. Action recognition, therefore, relies primarily on vision-based action recognition mechanisms in situations that require simultaneous action observation and execution, such as social interactions. The results suggest caution when associating social behaviour in social interactions with motor based information. PMID:27029781

  2. Graph signatures for visual analytics.

    PubMed

    Wong, Pak Chung; Foote, Harlan; Chin, George; Mackey, Patrick; Perrine, Ken

    2006-01-01

    We present a visual analytics technique to explore graphs using the concept of a data signature. A data signature, in our context, is a multidimensional vector that captures the local topology information surrounding each graph node. Signature vectors extracted from a graph are projected onto a low-dimensional scatterplot through the use of scaling. The resultant scatterplot, which reflects the similarities of the vectors, allows analysts to examine the graph structures and their corresponding real-life interpretations through repeated use of brushing and linking between the two visualizations. The interpretation of the graph structures is based on the outcomes of multiple participatory analysis sessions with intelligence analysts conducted by the authors at the Pacific Northwest National Laboratory. The paper first uses three public domain data sets with either well-known or obvious features to explain the rationale of our design and illustrate its results. More advanced examples are then used in a customized usability study to evaluate the effectiveness and efficiency of our approach. The study results reveal not only the limitations and weaknesses of the traditional approach based solely on graph visualization, but also the advantages and strengths of our signature-guided approach presented in the paper.

  3. Saccade Adaptation and Visual Uncertainty

    PubMed Central

    Souto, David; Gegenfurtner, Karl R.; Schütz, Alexander C.

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty. PMID:27252635

  4. Saccade Adaptation and Visual Uncertainty.

    PubMed

    Souto, David; Gegenfurtner, Karl R; Schütz, Alexander C

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty.

  5. Visualization of Scalar Adaptive Mesh Refinement Data

    SciTech Connect

    VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

    2007-12-06

    Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.

  6. Visualization Tools for Adaptive Mesh Refinement Data

    SciTech Connect

    Weber, Gunther H.; Beckner, Vincent E.; Childs, Hank; Ligocki,Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

    2007-05-09

    Adaptive Mesh Refinement (AMR) is a highly effective method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations that must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR visualization research and tools and describe how VisIt currently handles AMR data.

  7. The Evolving Leadership Path of Visual Analytics

    SciTech Connect

    Kluse, Michael; Peurrung, Anthony J.; Gracio, Deborah K.

    2012-01-02

    This is a requested book chapter for an internationally authored book on visual analytics and related fields, coordianted by a UK university and to be published by Springer in 2012. This chapter is an overview of the leadship strategies that PNNL's Jim Thomas and other stakeholders used to establish visual analytics as a field, and how those strategies may evolve in the future.

  8. Developing Guidelines for Assessing Visual Analytics Environments

    SciTech Connect

    Scholtz, Jean

    2011-07-01

    In this paper, we develop guidelines for evaluating visual analytic environments based on a synthesis of reviews for the entries to the 2009 Visual Analytics Science and Technology (VAST) Symposium Challenge and from a user study with professional intelligence analysts. By analyzing the 2009 VAST Challenge reviews we gained a better understanding of what is important to our reviewers, both visualization researchers and professional analysts. We also report on a small user study with professional analysts to determine the important factors that they use in evaluating visual analysis systems. We then looked at guidelines developed by researchers in various domains and synthesized these into an initial set for use by others in the community. In a second part of the user study, we looked at guidelines for a new aspect of visual analytic systems – the generation of reports. Future visual analytic systems have been challenged to help analysts generate their reports. In our study we worked with analysts to understand the criteria they used to evaluate the quality of analytic reports. We propose that this knowledge will be useful as researchers look at systems to automate some of the report generation.1 Based on these efforts, we produced some initial guidelines for evaluating visual analytic environment and for evaluation of analytic reports. It is important to understand that these guidelines are initial drafts and are limited in scope because of the type of tasks for which the visual analytic systems used in the studies in this paper were designed. More research and refinement is needed by the Visual Analytics Community to provide additional evaluation guidelines for different types of visual analytic environments.

  9. Visual Analytics for Roof Savings Calculator Ensembles

    SciTech Connect

    Jones, Chad; New, Joshua Ryan; Sanyal, Jibonananda; Ma, Kwan-Liu

    2012-01-01

    The Roof Savings Calculator (RSC) has been deployed for DOE as an industry-consensus, web-based tool for easily running complex building energy simulations. These simulations allow both homeowners and experts to determine building-specific cost and energy savings for modern roof and attic technologies. Using a database of over 3 million RSC simulations for different combinations of parameters, we have built a visual analytics tool to assist in the exploration and identification of features in the data. Since the database contains multiple variables, both categorical and continuous, we employ a coordinated multi-view approach that allows coordinated feature exploration through multiple visualizations at once. The main component of our system, a parallel coordinates view, has been adapted to handle large-scale, mixed data types as are found in RSC simulations. Other visualizations include map coordinated plots, high dynamic range (HDR) line plot rendering, and an intuitive user interface. We demonstrate these techniques with several use cases that have helped identify software and parametric simulation issues.

  10. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  11. Visual Text Analytics for Impromptu Analysts

    SciTech Connect

    Love, Oriana J.; Best, Daniel M.; Bruce, Joseph R.; Dowson, Scott T.; Larmey, Christopher S.

    2011-10-23

    The Scalable Reasoning System (SRS) is a lightweight visual analytics framework that makes analytical capabilities widely accessible to a class of users we have deemed “impromptu analysts.” By focusing on a deployment of SRS, the Lessons Learned Explorer (LLEx), we examine how to develop visualizations around analytical-oriented goals and data availability. We discuss how to help impromptu analysts to explore deeper patterns. Through designing consistent interactions, we arrive at an interdependent view capable of showcasing patterns. With the combination of SRS widget visualizations and interactions around the underlying textual data, we aim to transition the casual, infrequent user into a viable–albeit impromptu–analyst.

  12. The forensic validity of visual analytics

    NASA Astrophysics Data System (ADS)

    Erbacher, Robert F.

    2008-01-01

    The wider use of visualization and visual analytics in wide ranging fields has led to the need for visual analytics capabilities to be legally admissible, especially when applied to digital forensics. This brings the need to consider legal implications when performing visual analytics, an issue not traditionally examined in visualization and visual analytics techniques and research. While digital data is generally admissible under the Federal Rules of Evidence [10][21], a comprehensive validation of the digital evidence is considered prudent. A comprehensive validation requires validation of the digital data under rules for authentication, hearsay, best evidence rule, and privilege. Additional issues with digital data arise when exploring digital data related to admissibility and the validity of what information was examined, to what extent, and whether the analysis process was sufficiently covered by a search warrant. For instance, a search warrant generally covers very narrow requirements as to what law enforcement is allowed to examine and acquire during an investigation. When searching a hard drive for child pornography, how admissible is evidence of an unrelated crime, i.e. drug dealing. This is further complicated by the concept of "in plain view". When performing an analysis of a hard drive what would be considered "in plain view" when analyzing a hard drive. The purpose of this paper is to discuss the issues of digital forensics and the related issues as they apply to visual analytics and identify how visual analytics techniques fit into the digital forensics analysis process, how visual analytics techniques can improve the legal admissibility of digital data, and identify what research is needed to further improve this process. The goal of this paper is to open up consideration of legal ramifications among the visualization community; the author is not a lawyer and the discussions are not meant to be inclusive of all differences in laws between states and

  13. Expanding the Frontiers of Visual Analytics and Visualization

    SciTech Connect

    Dill, John; Earnshaw, Rae; Kasik, David; Vince, John; Wong, Pak C.

    2012-05-31

    Expanding the Frontiers of Visual Analytics and Visualization contains international contributions by leading researchers from within the field. Dedicated to the memory of Jim Thomas, the book begins with the dynamics of evolving a vision based on some of the principles that Jim and colleagues established and in which Jim’s leadership was evident. This is followed by chapters in the areas of visual analytics, visualization, interaction, modelling, architecture, and virtual reality, before concluding with the key area of technology transfer to industry.

  14. Building Adoption of Visual Analytics Software

    SciTech Connect

    Chinchor, Nancy; Cook, Kristin A.; Scholtz, Jean

    2012-01-05

    Adoption of technology is always difficult. Issues such as having the infrastructure necessary to support the technology, training for users, integrating the technology into current processes and tools, and having the time, managerial support, and necessary funds need to be addressed. In addition to these issues, the adoption of visual analytics tools presents specific challenges that need to be addressed. This paper discusses technology adoption challenges and approaches for visual analytics technologies.

  15. Visual adaptation and face perception

    PubMed Central

    Webster, Michael A.; MacLeod, Donald I. A.

    2011-01-01

    The appearance of faces can be strongly affected by the characteristics of faces viewed previously. These perceptual after-effects reflect processes of sensory adaptation that are found throughout the visual system, but which have been considered only relatively recently in the context of higher level perceptual judgements. In this review, we explore the consequences of adaptation for human face perception, and the implications of adaptation for understanding the neural-coding schemes underlying the visual representation of faces. The properties of face after-effects suggest that they, in part, reflect response changes at high and possibly face-specific levels of visual processing. Yet, the form of the after-effects and the norm-based codes that they point to show many parallels with the adaptations and functional organization that are thought to underlie the encoding of perceptual attributes like colour. The nature and basis for human colour vision have been studied extensively, and we draw on ideas and principles that have been developed to account for norms and normalization in colour vision to consider potential similarities and differences in the representation and adaptation of faces. PMID:21536555

  16. Visual Analytics and Storytelling through Video

    SciTech Connect

    Wong, Pak C.; Perrine, Kenneth A.; Mackey, Patrick S.; Foote, Harlan P.; Thomas, Jim

    2005-10-31

    This paper supplements a video clip submitted to the Video Track of IEEE Symposium on Information Visualization 2005. The original video submission applies a two-way storytelling approach to demonstrate the visual analytics capabilities of a new visualization technique. The paper presents our video production philosophy, describes the plot of the video, explains the rationale behind the plot, and finally, shares our production experiences with our readers.

  17. Visual Analytics for Law Enforcement: Deploying a Service-Oriented Analytic Framework for Web-based Visualization

    SciTech Connect

    Dowson, Scott T.; Bruce, Joseph R.; Best, Daniel M.; Riensche, Roderick M.; Franklin, Lyndsey; Pike, William A.

    2009-04-14

    This paper presents key components of the Law Enforcement Information Framework (LEIF) that provides communications, situational awareness, and visual analytics tools in a service-oriented architecture supporting web-based desktop and handheld device users. LEIF simplifies interfaces and visualizations of well-established visual analytical techniques to improve usability. Advanced analytics capability is maintained by enhancing the underlying processing to support the new interface. LEIF development is driven by real-world user feedback gathered through deployments at three operational law enforcement organizations in the US. LEIF incorporates a robust information ingest pipeline supporting a wide variety of information formats. LEIF also insulates interface and analytical components from information sources making it easier to adapt the framework for many different data repositories.

  18. Knowledge Generation Model for Visual Analytics.

    PubMed

    Sacha, Dominik; Stoffel, Andreas; Stoffel, Florian; Kwon, Bum Chul; Ellis, Geoffrey; Keim, Daniel A

    2014-12-01

    Visual analytics enables us to analyze huge information spaces in order to support complex decision making and data exploration. Humans play a central role in generating knowledge from the snippets of evidence emerging from visual data analysis. Although prior research provides frameworks that generalize this process, their scope is often narrowly focused so they do not encompass different perspectives at different levels. This paper proposes a knowledge generation model for visual analytics that ties together these diverse frameworks, yet retains previously developed models (e.g., KDD process) to describe individual segments of the overall visual analytic processes. To test its utility, a real world visual analytics system is compared against the model, demonstrating that the knowledge generation process model provides a useful guideline when developing and evaluating such systems. The model is used to effectively compare different data analysis systems. Furthermore, the model provides a common language and description of visual analytic processes, which can be used for communication between researchers. At the end, our model reflects areas of research that future researchers can embark on. PMID:26356874

  19. Knowledge Generation Model for Visual Analytics.

    PubMed

    Sacha, Dominik; Stoffel, Andreas; Stoffel, Florian; Kwon, Bum Chul; Ellis, Geoffrey; Keim, Daniel A

    2014-12-01

    Visual analytics enables us to analyze huge information spaces in order to support complex decision making and data exploration. Humans play a central role in generating knowledge from the snippets of evidence emerging from visual data analysis. Although prior research provides frameworks that generalize this process, their scope is often narrowly focused so they do not encompass different perspectives at different levels. This paper proposes a knowledge generation model for visual analytics that ties together these diverse frameworks, yet retains previously developed models (e.g., KDD process) to describe individual segments of the overall visual analytic processes. To test its utility, a real world visual analytics system is compared against the model, demonstrating that the knowledge generation process model provides a useful guideline when developing and evaluating such systems. The model is used to effectively compare different data analysis systems. Furthermore, the model provides a common language and description of visual analytic processes, which can be used for communication between researchers. At the end, our model reflects areas of research that future researchers can embark on.

  20. Cognitive Foundations for Visual Analytics

    SciTech Connect

    Greitzer, Frank L.; Noonan, Christine F.; Franklin, Lyndsey

    2011-02-25

    In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions.

  1. A graph algebra for scalable visual analytics.

    PubMed

    Shaverdian, Anna A; Zhou, Hao; Michailidis, George; Jagadish, Hosagrahar V

    2012-01-01

    Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data. PMID:24806630

  2. A graph algebra for scalable visual analytics.

    PubMed

    Shaverdian, Anna A; Zhou, Hao; Michailidis, George; Jagadish, Hosagrahar V

    2012-01-01

    Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data.

  3. SciDAC Visualization and Analytics Center for Enabling Technologies

    SciTech Connect

    Joy, Kenneth I.

    2014-09-14

    This project focuses on leveraging scientific visualization and analytics software technology as an enabling technology for increasing scientific productivity and insight. Advances in computational technology have resulted in an "information big bang," which in turn has created a significant data understanding challenge. This challenge is widely acknowledged to be one of the primary bottlenecks in contemporary science. The vision for our Center is to respond directly to that challenge by adapting, extending, creating when necessary and deploying visualization and data understanding technologies for our science stakeholders. Using an organizational model as a Visualization and Analytics Center for Enabling Technologies (VACET), we are well positioned to be responsive to the needs of a diverse set of scientific stakeholders in a coordinated fashion using a range of visualization, mathematics, statistics, computer and computational science and data management technologies.

  4. Visualizing Flow of Uncertainty through Analytical Processes.

    PubMed

    Wu, Yingcai; Yuan, Guo-Xun; Ma, Kwan-Liu

    2012-12-01

    Uncertainty can arise in any stage of a visual analytics process, especially in data-intensive applications with a sequence of data transformations. Additionally, throughout the process of multidimensional, multivariate data analysis, uncertainty due to data transformation and integration may split, merge, increase, or decrease. This dynamic characteristic along with other features of uncertainty pose a great challenge to effective uncertainty-aware visualization. This paper presents a new framework for modeling uncertainty and characterizing the evolution of the uncertainty information through analytical processes. Based on the framework, we have designed a visual metaphor called uncertainty flow to visually and intuitively summarize how uncertainty information propagates over the whole analysis pipeline. Our system allows analysts to interact with and analyze the uncertainty information at different levels of detail. Three experiments were conducted to demonstrate the effectiveness and intuitiveness of our design.

  5. Comparison of open source visual analytics toolkits.

    SciTech Connect

    Crossno, Patricia Joyce; Harger, John R.

    2010-11-01

    We present the results of the first stage of a two-stage evaluation of open source visual analytics packages. This stage is a broad feature comparison over a range of open source toolkits. Although we had originally intended to restrict ourselves to comparing visual analytics toolkits, we quickly found that very few were available. So we expanded our study to include information visualization, graph analysis, and statistical packages. We examine three aspects of each toolkit: visualization functions, analysis capabilities, and development environments. With respect to development environments, we look at platforms, language bindings, multi-threading/parallelism, user interface frameworks, ease of installation, documentation, and whether the package is still being actively developed.

  6. Predictive properties of visual adaptation.

    PubMed

    Chopin, Adrien; Mamassian, Pascal

    2012-04-10

    What humans perceive depends in part on what they have previously experienced. After repeated exposure to one stimulus, adaptation takes place in the form of a negative correlation between the current percept and the last displayed stimuli. Previous work has shown that this negative dependence can extend to a few minutes in the past, but the precise extent and nature of the dependence in vision is still unknown. In two experiments based on orientation judgments, we reveal a positive dependence of a visual percept with stimuli presented remotely in the past, unexpectedly and in contrast to what is known for the recent past. Previous theories of adaptation have postulated that the visual system attempts to calibrate itself relative to an ideal norm or to the recent past. We propose instead that the remote past is used to estimate the world's statistics and that this estimate becomes the reference. According to this new framework, adaptation is predictive: the most likely forthcoming percept is the one that helps the statistics of the most recent percepts match that of the remote past.

  7. Online Visual Analytics of Text Streams.

    PubMed

    Liu, Shixia; Yin, Jialun; Wang, Xiting; Cui, Weiwei; Cao, Kelei; Pei, Jian

    2016-11-01

    We present an online visual analytics approach to helping users explore and understand hierarchical topic evolution in high-volume text streams. The key idea behind this approach is to identify representative topics in incoming documents and align them with the existing representative topics that they immediately follow (in time). To this end, we learn a set of streaming tree cuts from topic trees based on user-selected focus nodes. A dynamic Bayesian network model has been developed to derive the tree cuts in the incoming topic trees to balance the fitness of each tree cut and the smoothness between adjacent tree cuts. By connecting the corresponding topics at different times, we are able to provide an overview of the evolving hierarchical topics. A sedimentation-based visualization has been designed to enable the interactive analysis of streaming text data from global patterns to local details. We evaluated our method on real-world datasets and the results are generally favorable.

  8. Visual Analytics Methodology for Eye Movement Studies.

    PubMed

    Andrienko, G; Andrienko, N; Burch, M; Weiskopf, D

    2012-12-01

    Eye movement analysis is gaining popularity as a tool for evaluation of visual displays and interfaces. However, the existing methods and tools for analyzing eye movements and scanpaths are limited in terms of the tasks they can support and effectiveness for large data and data with high variation. We have performed an extensive empirical evaluation of a broad range of visual analytics methods used in analysis of geographic movement data. The methods have been tested for the applicability to eye tracking data and the capability to extract useful knowledge about users' viewing behaviors. This allowed us to select the suitable methods and match them to possible analysis tasks they can support. The paper describes how the methods work in application to eye tracking data and provides guidelines for method selection depending on the analysis tasks.

  9. Visual Analytics for Power Grid Contingency Analysis

    SciTech Connect

    Wong, Pak C.; Huang, Zhenyu; Chen, Yousu; Mackey, Patrick S.; Jin, Shuangshuang

    2014-01-20

    Contingency analysis is the process of employing different measures to model scenarios, analyze them, and then derive the best response to remove the threats. This application paper focuses on a class of contingency analysis problems found in the power grid management system. A power grid is a geographically distributed interconnected transmission network that transmits and delivers electricity from generators to end users. The power grid contingency analysis problem is increasingly important because of both the growing size of the underlying raw data that need to be analyzed and the urgency to deliver working solutions in an aggressive timeframe. Failure to do so may bring significant financial, economic, and security impacts to all parties involved and the society at large. The paper presents a scalable visual analytics pipeline that transforms about 100 million contingency scenarios to a manageable size and form for grid operators to examine different scenarios and come up with preventive or mitigation strategies to address the problems in a predictive and timely manner. Great attention is given to the computational scalability, information scalability, visual scalability, and display scalability issues surrounding the data analytics pipeline. Most of the large-scale computation requirements of our work are conducted on a Cray XMT multi-threaded parallel computer. The paper demonstrates a number of examples using western North American power grid models and data.

  10. Epinome: a visual-analytics workbench for epidemiology data.

    PubMed

    Livnat, Yarden; Rhyne, Theresa-Marie; Samore, Matthew H

    2012-01-01

    Early detection and rapid response to infectious-disease outbreaks rely on effective decision making based on information from disparate sources. To improve decision-making in outbreak detection and response, it's important to understand how public health practitioners seek relevant information. Epinome, a user-centric visual-analytics system, supports research on decision-making in public health, particularly evaluation of information search strategies. Epinome facilitates investigation of scripted high-fidelity large-scale simulated disease outbreaks. Its dynamic environment seamlessly evolves and adapts as the user's tasks and focus change. This video shows how the Epinome system facilitates interactive simulations of disease outbreaks.

  11. Semantic Interaction for Visual Analytics: Toward Coupling Cognition and Computation

    SciTech Connect

    Endert, Alexander

    2014-07-01

    The dissertation discussed in this article [1] was written in the midst of an era of digitization. The world is becoming increasingly instrumented with sensors, monitoring, and other methods for generating data describing social, physical, and natural phenomena. Thus, data exist with the potential of being analyzed to uncover, or discover, the phenomena from which it was created. However, as the analytic models leveraged to analyze these data continue to increase in complexity and computational capability, how can visualizations and user interaction methodologies adapt and evolve to continue to foster discovery and sensemaking?

  12. Adaptive encoding in the visual pathway.

    PubMed

    Lesica, Nicholas A; Boloori, Alireza S; Stanley, Garrett B

    2003-02-01

    In a natural setting, the mean luminance and contrast of the light within a visual neuron's receptive field are constantly changing as the eyes saccade across complex scenes. Adaptive mechanisms modulate filtering properties of the early visual pathway in response to these variations, allowing the system to maintain differential sensitivity to nonstationary stimuli. An adaptive variant of the reverse correlation technique is used to characterize these changes during single trials. Properties of the adaptive reverse correlation algorithm were investigated via simulation. Analysis of data collected from the mammalian visual system demonstrates the ability to continuously track adaptive changes in the encoding scheme. The adaptive estimation approach provides a framework for characterizing the role of adaptation in natural scene viewing. PMID:12613554

  13. The Human is the Loop: New Directions for Visual Analytics

    SciTech Connect

    Endert, Alexander; Hossain, Shahriar H.; Ramakrishnan, Naren; North, Chris; Fiaux, Patrick; Andrews, Christopher

    2014-01-28

    Visual analytics is the science of marrying interactive visualizations and analytic algorithms to support exploratory knowledge discovery in large datasets. We argue for a shift from a ‘human in the loop’ philosophy for visual analytics to a ‘human is the loop’ viewpoint, where the focus is on recognizing analysts’ work processes, and seamlessly fitting analytics into that existing interactive process. We survey a range of projects that provide visual analytic support contextually in the sensemaking loop, and outline a research agenda along with future challenges.

  14. Production-quality Tools for Adaptive Mesh RefinementVisualization

    SciTech Connect

    Weber, Gunther H.; Childs, Hank; Bonnell, Kathleen; Meredith,Jeremy; Miller, Mark; Whitlock, Brad; Bethel, E. Wes

    2007-10-25

    Adaptive Mesh Refinement (AMR) is a highly effectivesimulation method for spanning a large range of spatiotemporal scales,such as astrophysical simulations that must accommodate ranges frominterstellar to sub-planetary. Most mainstream visualization tools stilllack support for AMR as a first class data type and AMR code teams usecustom built applications for AMR visualization. The Department ofEnergy's (DOE's) Science Discovery through Advanced Computing (SciDAC)Visualization and Analytics Center for Enabling Technologies (VACET) isextending and deploying VisIt, an open source visualization tool thataccommodates AMR as a first-class data type, for use asproduction-quality, parallel-capable AMR visual data analysisinfrastructure. This effort will help science teams that use AMR-basedsimulations and who develop their own AMR visual data analysis softwareto realize cost and labor savings.

  15. Social Media Visual Analytics for Events

    NASA Astrophysics Data System (ADS)

    Diakopoulos, Nicholas; Naaman, Mor; Yazdani, Tayebeh; Kivran-Swaine, Funda

    For large-scale multimedia events such as televised debates and speeches, the amount of content on social media channels such as Facebook or Twitter can easily become overwhelming, yet still contain information that may aid and augment understanding of the multimedia content via individual social media items, or aggregate information from the crowd's response. In this work we discuss this opportunity in the context of a social media visual analytic tool, Vox Civitas, designed to help journalists, media professionals, or other researchers make sense of large-scale aggregations of social media content around multimedia broadcast events. We discuss the design of the tool, present and evaluate the text analysis techniques used to enable the presentation, and detail the visual and interaction design. We provide an exploratory evaluation based on a user study in which journalists interacted with the system to analyze and report on a dataset of over one 100 000 Twitter messages collected during the broadcast of the U.S. State of the Union presidential address in 2010.

  16. Beyond Control Panels: Direct Manipulation for Visual Analytics

    SciTech Connect

    Endert, Alexander; Bradel, Lauren; North, Chris

    2013-07-19

    Information Visualization strives to provide visual representations through which users can think about and gain insight into information. By leveraging the visual and cognitive systems of humans, complex relationships and phenomena occurring within datasets can be uncovered by exploring information visually. Interaction metaphors for such visualizations are designed to enable users direct control over the filters, queries, and other parameters controlling how the data is visually represented. Through the evolution of information visualization, more complex mathematical and data analytic models are being used to visualize relationships and patterns in data – creating the field of Visual Analytics. However, the expectations for how users interact with these visualizations has remained largely unchanged – focused primarily on the direct manipulation of parameters of the underlying mathematical models. In this article we present an opportunity to evolve the methodology for user interaction from the direct manipulation of parameters through visual control panels, to interactions designed specifically for visual analytic systems. Instead of focusing on traditional direct manipulation of mathematical parameters, the evolution of the field can be realized through direct manipulation within the visual representation – where users can not only gain insight, but also interact. This article describes future directions and research challenges that fundamentally change the meaning of direct manipulation with regards to visual analytics, advancing the Science of Interaction.

  17. Photoreceptor processes in visual adaptation.

    PubMed

    Ripps, H; Pepperberg, D R

    1987-01-01

    In this paper we have stressed two experimental results in need of explanation: (i) the reduced efficacy with which (remaining, abundant) rhodopsin in the light-adapted receptor mediates the flash response; and (ii) the disparity in conditions of irradiation (weak background vs. extensive bleaching) leading to equivalent conditions of threshold. The model discussed above suggests, in molecular terms, a possible basis for both properties of receptor adaptation. On the view developed here, property (i) derives from the ability of photoactivated or bleached pigment (R or B) to restrict dramatically the availability of a substance required for phototransduction. Property (ii) derives in large part from the pronounced disparity in the effectiveness of R (during illumination) and B (remaining after illumination) in reducing the availability of this substance. On this view, the "equivalence" of threshold elevation in states of light- vs. dark-adaptation derives from an overall equality of a product of factors (Q, Etot/Es, and J of equation 2). Under all but extreme conditions, this aggregate of factors is dominated by the term Etot/Es, reflecting the functional state of E. PMID:3317149

  18. High Performance Visualization using Query-Driven Visualizationand Analytics

    SciTech Connect

    Bethel, E. Wes; Campbell, Scott; Dart, Eli; Shalf, John; Stockinger, Kurt; Wu, Kesheng

    2006-06-15

    Query-driven visualization and analytics is a unique approach for high-performance visualization that offers new capabilities for knowledge discovery and hypothesis testing. The new capabilities akin to finding needles in haystacks are the result of combining technologies from the fields of scientific visualization and scientific data management. This approach is crucial for rapid data analysis and visualization in the petascale regime. This article describes how query-driven visualization is applied to a hero-sized network traffic analysis problem.

  19. Beyond control panels: direct manipulation for visual analytics.

    PubMed

    Endert, Alex; Bradel, Lauren; North, Chris

    2013-01-01

    To tackle the onset of big data, visual analytics seeks to marry the human intuition of visualization with mathematical models' analytical horsepower. A critical question is, how will humans interact with and steer these complex models? Initially, users applied direct manipulation to such models the same way they applied it to simpler visualizations in the premodel era--using control panels to directly manipulate model parameters. However, opportunities are arising for direct manipulation of the model outputs, where the users' thought processes take place, rather than the inputs. This article presents this new agenda for direct manipulation for visual analytics.

  20. Using Visual Analytics Tool for Improving Data Comprehension

    ERIC Educational Resources Information Center

    Géryk, Jan

    2015-01-01

    The efficacy of animated data visualizations in comparison with static data visualizations is still inconclusive. Some researches resulted that the failure to find out the benefits of animations may relate to the way how they are constructed and perceived. In this paper, we present visual analytics (VA) tool which makes use of enhanced animated…

  1. Visual analytics for immunologists: Data compression and fractal distributions.

    PubMed

    Naumova, Elena N

    2010-07-01

    Visual analytics is the science of analytical reasoning that facilitates research through the use of interactive visual interfaces. New techniques of visual analytics are designed to aid the understanding of complex systems versus traditional blind-context rules to explore massive volumes of interrelated data. Nowhere else is visualization more important in analysis than in the emerging fields of life sciences, where amounts of collected data grow increasingly in exponential rates.The complexity of the immune system in immunology makes visual analytics especially important for understanding how this system works. In this context, our effort should be focused on avoiding accurate but potentially misleading use of visual interfaces. The proposed approach of data compression and visualization that reveal structural and functional features of immune responses enhances systemic and comprehensive description and provides the platform for hypothesis generation. Further, this approach can evolve into a powerful visual-analytical tool for prospective and real-time monitoring and can provide an intuitive and interpretable illustration of vital dynamics that govern immune responses in an individual and populations.The undertaken explorations demonstrate the critical role of novel techniques of visual analytics in stimulating research in immunology and other life sciences and in leading us to understanding of complex biological systems and processes.

  2. Top Ten Interaction Challenges in Extreme-Scale Visual Analytics

    SciTech Connect

    Wong, Pak C.; Shen, Han-Wei; Chen, Chaomei

    2012-05-31

    The chapter presents ten selected user interfaces and interaction challenges in extreme-scale visual analytics. The study of visual analytics is often referred to as 'the science of analytical reasoning facilitated by interactive visual interfaces' in the literature. The discussion focuses on the issues of applying visual analytics technologies to extreme-scale scientific and non-scientific data ranging from petabyte to exabyte in sizes. The ten challenges are: in situ interactive analysis, user-driven data reduction, scalability and multi-level hierarchy, representation of evidence and uncertainty, heterogeneous data fusion, data summarization and triage for interactive query, analytics of temporally evolving features, the human bottleneck, design and engineering development, and the Renaissance of conventional wisdom. The discussion addresses concerns that arise from different areas of hardware, software, computation, algorithms, and human factors. The chapter also evaluates the likelihood of success in meeting these challenges in the near future.

  3. Beyond Usability: Evaluation Aspects of Visual Analytic Environments

    SciTech Connect

    Scholtz, Jean

    2006-10-29

    A new field of research, visual analytics, has recently been introduced. This has been defined as “the science of analytical reasoning facilitated by visual interfaces." Visual analytic environments, therefore, support analytical reasoning using visual representations and interactions, with data representations and transformation capabilities, to support production, presentation and dissemination. As researchers begin to develop visual analytic environments, it will be advantageous to develop metrics and methodologies to help researchers measure the progress of their work and understand the impact their work will have on the users who will work in such environments. This paper presents five areas or aspects of visual analytic environments that should be considered as metrics and methodologies for evaluation are developed. Evaluation aspects need to include usability, but it is necessary to go beyond basic usability. The areas of situation awareness, collaboration, interaction, creativity, and utility are proposed as areas for initial consideration. The steps that need to be undertaken to develop systematic evaluation methodologies and metrics for visual analytic environments are outlined.

  4. Web-based Visual Analytics for Extreme Scale Climate Science

    SciTech Connect

    Steed, Chad A; Evans, Katherine J; Harney, John F; Jewell, Brian C; Shipman, Galen M; Smith, Brian E; Thornton, Peter E; Williams, Dean N.

    2014-01-01

    In this paper, we introduce a Web-based visual analytics framework for democratizing advanced visualization and analysis capabilities pertinent to large-scale earth system simulations. We address significant limitations of present climate data analysis tools such as tightly coupled dependencies, ineffi- cient data movements, complex user interfaces, and static visualizations. Our Web-based visual analytics framework removes critical barriers to the widespread accessibility and adoption of advanced scientific techniques. Using distributed connections to back-end diagnostics, we minimize data movements and leverage HPC platforms. We also mitigate system dependency issues by employing a RESTful interface. Our framework embraces the visual analytics paradigm via new visual navigation techniques for hierarchical parameter spaces, multi-scale representations, and interactive spatio-temporal data mining methods that retain details. Although generalizable to other science domains, the current work focuses on improving exploratory analysis of large-scale Community Land Model (CLM) and Community Atmosphere Model (CAM) simulations.

  5. Visual Analytics: Building a Vibrant and Resilient National Science

    SciTech Connect

    Wong, Pak C.; Thomas, James J.

    2009-09-20

    Five years after the science of visual analytics was formally established, we attempt to use two different studies to assess the current state of the community and evaluate the progress the community has made in the past few years. The first study involves a comparison analysis of intellectual and scholastic accomplishments recently made by the visual analytics community. The second one aims to measure the degree of community reach and internet penetration of visual-analytics-related resources. This paper describes our efforts to harvest the study data, conduct analysis, and make interpretations based on parallel comparisons with five other established computer science areas.

  6. Web-Based Visual Analytics for Social Media

    SciTech Connect

    Best, Daniel M.; Bruce, Joseph R.; Dowson, Scott T.; Love, Oriana J.; McGrath, Liam R.

    2012-05-20

    Social media provides a rich source of data that reflects current trends and public opinion on a multitude of topics. The data can be harvested from Twitter, Facebook, Blogs, and other social applications. The high rate of adoption of social media has created a domain that has an ever expanding volume of data that make it difficult to use the raw data for analysis. Information visual analytics is key in drawing out features of interest in social media. The Scalable Reasoning System is an application that couples a back end server performing analysis algorithms and an intuitive front end visualization to allow for investigation. We provide a componentized system that can be rapidly adapted to customer needs such that the information they are most interested in is brought to their attention through the application. To this end, we have developed a social media application for use by emergency operations for the city of Seattle to show current weather and traffic trends which is important for their tasks.

  7. The Case for Visual Analytics of Arsenic Concentrations in Foods

    PubMed Central

    Johnson, Matilda O.; Cohly, Hari H.P.; Isokpehi, Raphael D.; Awofolu, Omotayo R.

    2010-01-01

    Arsenic is a naturally occurring toxic metal and its presence in food could be a potential risk to the health of both humans and animals. Prolonged ingestion of arsenic contaminated water may result in manifestations of toxicity in all systems of the body. Visual Analytics is a multidisciplinary field that is defined as the science of analytical reasoning facilitated by interactive visual interfaces. The concentrations of arsenic vary in foods making it impractical and impossible to provide regulatory limit for each food. This review article presents a case for the use of visual analytics approaches to provide comparative assessment of arsenic in various foods. The topics covered include (i) metabolism of arsenic in the human body; (ii) arsenic concentrations in various foods; (ii) factors affecting arsenic uptake in plants; (ii) introduction to visual analytics; and (iv) benefits of visual analytics for comparative assessment of arsenic concentration in foods. Visual analytics can provide an information superstructure of arsenic in various foods to permit insightful comparative risk assessment of the diverse and continually expanding data on arsenic in food groups in the context of country of study or origin, year of study, method of analysis and arsenic species. PMID:20623005

  8. The case for visual analytics of arsenic concentrations in foods.

    PubMed

    Johnson, Matilda O; Cohly, Hari H P; Isokpehi, Raphael D; Awofolu, Omotayo R

    2010-05-01

    Arsenic is a naturally occurring toxic metal and its presence in food could be a potential risk to the health of both humans and animals. Prolonged ingestion of arsenic contaminated water may result in manifestations of toxicity in all systems of the body. Visual Analytics is a multidisciplinary field that is defined as the science of analytical reasoning facilitated by interactive visual interfaces. The concentrations of arsenic vary in foods making it impractical and impossible to provide regulatory limit for each food. This review article presents a case for the use of visual analytics approaches to provide comparative assessment of arsenic in various foods. The topics covered include (i) metabolism of arsenic in the human body; (ii) arsenic concentrations in various foods; (ii) factors affecting arsenic uptake in plants; (ii) introduction to visual analytics; and (iv) benefits of visual analytics for comparative assessment of arsenic concentration in foods. Visual analytics can provide an information superstructure of arsenic in various foods to permit insightful comparative risk assessment of the diverse and continually expanding data on arsenic in food groups in the context of country of study or origin, year of study, method of analysis and arsenic species.

  9. VAFLE: visual analytics of firewall log events

    NASA Astrophysics Data System (ADS)

    Ghoniem, Mohammad; Shurkhovetskyy, Georgiy; Bahey, Ahmed; Otjacques, Benoît.

    2013-12-01

    In this work, we present VAFLE, an interactive network security visualization prototype for the analysis of firewall log events. Keeping it simple yet effective for analysts, we provide multiple coordinated interactive visualizations augmented with clustering capabilities customized to support anomaly detection and cyber situation awareness. We evaluate the usefulness of the prototype in a use case with network traffic datasets from previous VAST Challenges, illustrating its effectiveness at promoting fast and well-informed decisions. We explain how a security analyst may spot suspicious traffic using VAFLE. We further assess its usefulness through a qualitative evaluation involving network security experts, whose feedback is reported and discussed.

  10. Analyte sensing mediated by adapter/carrier molecules

    DOEpatents

    Bayley, Hagan; Braha, Orit; Gu, LiQun

    2002-07-30

    This invention relates to an improved method and system for sensing of one or more analytes. A host molecule, which serves as an adapter/carrier, is used to facilitate interaction between the analyte and the sensor element. A detectable signal is produced reflecting the identity and concentration of analyte present.

  11. Adaptation and visual search in mammographic images.

    PubMed

    Kompaniez-Dunigan, Elysse; Abbey, Craig K; Boone, John M; Webster, Michael A

    2015-05-01

    Radiologists face the visually challenging task of detecting suspicious features within the complex and noisy backgrounds characteristic of medical images. We used a search task to examine whether the salience of target features in x-ray mammograms could be enhanced by prior adaptation to the spatial structure of the images. The observers were not radiologists, and thus had no diagnostic training with the images. The stimuli were randomly selected sections from normal mammograms previously classified with BIRADS Density scores of "fatty" versus "dense," corresponding to differences in the relative quantities of fat versus fibroglandular tissue. These categories reflect conspicuous differences in visual texture, with dense tissue being more likely to obscure lesion detection. The targets were simulated masses corresponding to bright Gaussian spots, superimposed by adding the luminance to the background. A single target was randomly added to each image, with contrast varied over five levels so that they varied from difficult to easy to detect. Reaction times were measured for detecting the target location, before or after adapting to a gray field or to random sequences of a different set of dense or fatty images. Observers were faster at detecting the targets in either dense or fatty images after adapting to the specific background type (dense or fatty) that they were searching within. Thus, the adaptation led to a facilitation of search performance that was selective for the background texture. Our results are consistent with the hypothesis that adaptation allows observers to more effectively suppress the specific structure of the background, thereby heightening visual salience and search efficiency.

  12. Adaptive optics without altering visual perception.

    PubMed

    Koenig, D E; Hart, N W; Hofer, H J

    2014-04-01

    Adaptive optics combined with visual psychophysics creates the potential to study the relationship between visual function and the retina at the cellular scale. This potential is hampered, however, by visual interference from the wavefront-sensing beacon used during correction. For example, we have previously shown that even a dim, visible beacon can alter stimulus perception (Hofer et al., 2012). Here we describe a simple strategy employing a longer wavelength (980nm) beacon that, in conjunction with appropriate restriction on timing and placement, allowed us to perform psychophysics when dark adapted without altering visual perception. The method was verified by comparing detection and color appearance of foveally presented small spot stimuli with and without the wavefront beacon present in 5 subjects. As an important caution, we found that significant perceptual interference can occur even with a subliminal beacon when additional measures are not taken to limit exposure. Consequently, the lack of perceptual interference should be verified for a given system, and not assumed based on invisibility of the beacon.

  13. Co-located collaborative visual analytics around a tabletop display.

    PubMed

    Isenberg, Petra; Fisher, Danyel; Paul, Sharoda A; Morris, Meredith Ringel; Inkpen, Kori; Czerwinski, Mary

    2012-05-01

    Co-located collaboration can be extremely valuable during complex visual analytics tasks. We present an exploratory study of a system designed to support collaborative visual analysis tasks on a digital tabletop display. Fifteen participant pairs employed Cambiera, a visual analytics system, to solve a problem involving 240 digital documents. Our analysis, supported by observations, system logs, questionnaires, and interview data, explores how pairs approached the problem around the table. We contribute a unique, rich understanding of how users worked together around the table and identify eight types of collaboration styles that can be used to identify how closely people work together while problem solving. We show how the closeness of teams’ collaboration and communication influenced how they performed on the task overall. We further discuss the role of the tabletop for visual analytics tasks and derive design implications for future co-located collaborative tabletop problem solving systems.

  14. Big data in medical informatics: improving education through visual analytics.

    PubMed

    Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

    2014-01-01

    A continuous effort to improve healthcare education today is currently driven from the need to create competent health professionals able to meet healthcare demands. Limited research reporting how educational data manipulation can help in healthcare education improvement. The emerging research field of visual analytics has the advantage to combine big data analysis and manipulation techniques, information and knowledge representation, and human cognitive strength to perceive and recognise visual patterns. The aim of this study was therefore to explore novel ways of representing curriculum and educational data using visual analytics. Three approaches of visualization and representation of educational data were presented. Five competencies at undergraduate medical program level addressed in courses were identified to inaccurately correspond to higher education board competencies. Different visual representations seem to have a potential in impacting on the ability to perceive entities and connections in the curriculum data.

  15. Visual adaptation--a reinterpretation: discussion.

    PubMed

    Laming, Donald

    2013-10-01

    This discussion paper seeks to reshape the contemporary understanding of visual adaptation. Received wisdom says that input luminance is scaled down in the retina. There is, first, a near-logarithmic compression described by the Naka-Rushton equation and, second, a control of gain (better attenuation) by feedback from the output of each ganglion cell that is equivalent to modifying the half-saturation constant in the Naka-Rushton equation. The reinterpretation proposed here asserts the following instead: (a) the scaling down in the retina is accomplished by receptive fields of different areas, which function over different ranges of luminance, ranges inversely proportional to the area of the receptive field. (b) The visual pathway is differentially coupled to the physical stimulus, so that the maintained discharge increases only as the square root of the luminance. (c) The Naka-Rushton equation describes merely the saturation of neural response as input increases; when a neuron is overloaded, output tends to regularity and onward transmission is blocked by a subsequent stage of differential coupling. Three existing studies of the relation between input to and output from retinal ganglion cells are reinterpreted in the light of this alternative view of visual adaptation.

  16. Visualization of adaptive mesh refinement data

    NASA Astrophysics Data System (ADS)

    Weber, Gunther H.; Hagen, Hans; Hamann, Bernd; Joy, Kenneth I.; Ligocki, Terry J.; Ma, Kwan-Liu; Shalf, John M.

    2001-05-01

    The complexity of physical phenomena often varies substantially over space and time. There can be regions where a physical phenomenon/quantity varies very little over a large extent. At the same time, there can be small regions where the same quantity exhibits highly complex variations. Adaptive mesh refinement (AMR) is a technique used in computational fluid dynamics to simulate phenomena with drastically varying scales concerning the complexity of the simulated variables. Using multiple nested grids of different resolutions, AMR combines the topological simplicity of structured-rectilinear grids, permitting efficient computational and storage, with the possibility to adapt grid resolutions in regions of complex behavior. We present methods for direct volume rendering of AMR data. Our methods utilize AMR grids directly for efficiency of the visualization process. We apply a hardware-accelerated rendering method to AMR data supporting interactive manipulation of color-transfer functions and viewing parameters. We also present a cell-projection-based rendering technique for AMR data.

  17. SciDAC Visualization and Analytics Center for EnablingTechnologies

    SciTech Connect

    Bethel, E. Wes; Johnson, Chris; Joy, Ken; Ahern, Sean; Pascucci,Valerio; Childs, Hank; Cohen, Jonathan; Duchaineau, Mark; Hamann, Bernd; Hansen, Charles; Laney, Dan; Lindstrom, Peter; Meredith, Jermey; Ostrouchov, George; Parker, Steven; Silva, Claudio; Sanderson, Allen; Tricoche, Xavier.

    2007-06-30

    The Visualization and Analytics Center for EnablingTechnologies (VACET) focuses on leveraging scientific visualization andanalytics software technology as an enabling technology for increasingscientific productivity and insight. Advances in computational technologyhave resulted in an 'information big bang,' which in turn has created asignificant data understanding challenge. This challenge is widelyacknowledged to be one of the primary bottlenecks in contemporaryscience. The vision of VACET is to adapt, extend, create when necessary,and deploy visual data analysis solutions that are responsive to theneeds of DOE'scomputational and experimental scientists. Our center isengineered to be directly responsive to those needs and to deliversolutions for use in DOE's large open computing facilities. The researchand development directly target data understanding problems provided byour scientific application stakeholders. VACET draws from a diverse setof visualization technology ranging from production quality applicationsand application frameworks to state-of-the-art algorithms forvisualization, analysis, analytics, data manipulation, and datamanagement.

  18. UAV visual signature suppression via adaptive materials

    NASA Astrophysics Data System (ADS)

    Barrett, Ron; Melkert, Joris

    2005-05-01

    Visual signature suppression (VSS) methods for several classes of aircraft from WWII on are examined and historically summarized. This study shows that for some classes of uninhabited aerial vehicles (UAVs), primary mission threats do not stem from infrared or radar signatures, but from the amount that an aircraft visually stands out against the sky. The paper shows that such visual mismatch can often jeopardize mission success and/or induce the destruction of the entire aircraft. A psycho-physioptical study was conducted to establish the definition and benchmarks of a Visual Cross Section (VCS) for airborne objects. This study was centered on combining the effects of size, shape, color and luminosity or effective illumance (EI) of a given aircraft to arrive at a VCS. A series of tests were conducted with a 6.6ft (2m) UAV which was fitted with optically adaptive electroluminescent sheets at altitudes of up to 1000 ft (300m). It was shown that with proper tailoring of the color and luminosity, the VCS of the aircraft dropped from more than 4,200cm2 to less than 1.8cm2 at 100m (the observed lower limit of the 20-20 human eye in this study). In laypersons terms this indicated that the UAV essentially "disappeared". This study concludes with an assessment of the weight and volume impact of such a Visual Suppression System (VSS) on the UAV, showing that VCS levels on this class UAV can be suppressed to below 1.8cm2 for aircraft gross weight penalties of only 9.8%.

  19. SeeDB: Efficient Data-Driven Visualization Recommendations to Support Visual Analytics

    PubMed Central

    Vartak, Manasi; Rahman, Sajjadur; Madden, Samuel; Parameswaran, Aditya; Polyzotis, Neoklis

    2015-01-01

    Data analysts often build visualizations as the first step in their analytical workflow. However, when working with high-dimensional datasets, identifying visualizations that show relevant or desired trends in data can be laborious. We propose SeeDB, a visualization recommendation engine to facilitate fast visual analysis: given a subset of data to be studied, SeeDB intelligently explores the space of visualizations, evaluates promising visualizations for trends, and recommends those it deems most “useful” or “interesting”. The two major obstacles in recommending interesting visualizations are (a) scale: evaluating a large number of candidate visualizations while responding within interactive time scales, and (b) utility: identifying an appropriate metric for assessing interestingness of visualizations. For the former, SeeDB introduces pruning optimizations to quickly identify high-utility visualizations and sharing optimizations to maximize sharing of computation across visualizations. For the latter, as a first step, we adopt a deviation-based metric for visualization utility, while indicating how we may be able to generalize it to other factors influencing utility. We implement SeeDB as a middleware layer that can run on top of any DBMS. Our experiments show that our framework can identify interesting visualizations with high accuracy. Our optimizations lead to multiple orders of magnitude speedup on relational row and column stores and provide recommendations at interactive time scales. Finally, we demonstrate via a user study the effectiveness of our deviation-based utility metric and the value of recommendations in supporting visual analytics. PMID:26779379

  20. Sunfall: a collaborative visual analytics system for astrophysics

    SciTech Connect

    Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

    2008-07-07

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  1. Big data and visual analytics in anaesthesia and health care.

    PubMed

    Simpao, A F; Ahumada, L M; Rehman, M A

    2015-09-01

    Advances in computer technology, patient monitoring systems, and electronic health record systems have enabled rapid accumulation of patient data in electronic form (i.e. big data). Organizations such as the Anesthesia Quality Institute and Multicenter Perioperative Outcomes Group have spearheaded large-scale efforts to collect anaesthesia big data for outcomes research and quality improvement. Analytics--the systematic use of data combined with quantitative and qualitative analysis to make decisions--can be applied to big data for quality and performance improvements, such as predictive risk assessment, clinical decision support, and resource management. Visual analytics is the science of analytical reasoning facilitated by interactive visual interfaces, and it can facilitate performance of cognitive activities involving big data. Ongoing integration of big data and analytics within anaesthesia and health care will increase demand for anaesthesia professionals who are well versed in both the medical and the information sciences.

  2. Big data and visual analytics in anaesthesia and health care.

    PubMed

    Simpao, A F; Ahumada, L M; Rehman, M A

    2015-09-01

    Advances in computer technology, patient monitoring systems, and electronic health record systems have enabled rapid accumulation of patient data in electronic form (i.e. big data). Organizations such as the Anesthesia Quality Institute and Multicenter Perioperative Outcomes Group have spearheaded large-scale efforts to collect anaesthesia big data for outcomes research and quality improvement. Analytics--the systematic use of data combined with quantitative and qualitative analysis to make decisions--can be applied to big data for quality and performance improvements, such as predictive risk assessment, clinical decision support, and resource management. Visual analytics is the science of analytical reasoning facilitated by interactive visual interfaces, and it can facilitate performance of cognitive activities involving big data. Ongoing integration of big data and analytics within anaesthesia and health care will increase demand for anaesthesia professionals who are well versed in both the medical and the information sciences. PMID:25627395

  3. Top Ten Challenges in Extreme-Scale Visual Analytics

    SciTech Connect

    Wong, Pak C.; Shen, Han-Wei; Johnson, Christopher R.; Chen, Chaomei; Ross, Rob

    2012-05-08

    In the current special issue of IEEE Computer Graphics and Applications (CG&A), researchers share their research and development (R&D) findings and results on applying visual analytics to extreme-scale data. Having surveyed the special issue articles and other related R&D efforts in the area, we have identified what we consider to be the top challenges of extreme-scale visual analytics. To cater to the diverse readership of CG&A, our discussion evaluates challenges in all areas of the field, including algorithms, hardware, software, engineering, and social issues.

  4. Evaluating Visual Analytics at the 2007 VAST Symposium Contest

    SciTech Connect

    Plaisant, Catherine; Grinstein, Georges; Scholtz, Jean; Whiting, Mark A.; O'Connell, Theresa; Laskowski, Sharon; Chien, Lynn; Tat, Annie; Wright, William; Gorg, Carsten; Lui, Zhicheng; Parekh, Neel; Singhal, Kanupriya; Stasko, John T.

    2008-03-01

    The second Visual Analytics Science and Technology (VAST) contest was held in conjunction with the 2007 IEEE VAST Symposium. A synthetic data set was created containing a known scenario with embedded threats, therefore providing ground truth. Participants used visual analytic tools to explore the heterogeneous data collection and find the evidence of illegal and possible terrorist activities in the data. We describe the contest and the evaluation methodology, then provide details on the results and the two winning entries. Lessons learned are reported from different points of view: contest committee, participants, judges, stake holders and other researchers.

  5. A web-enabled visualization toolkit for geovisual analytics

    NASA Astrophysics Data System (ADS)

    Ho, Quan; Lundblad, Patrik; Åström, Tobias; Jern, Mikael

    2011-01-01

    We introduce a framework and class library (GAV Flash) implemented in Adobe's ActionScript, designed with the intention to significantly shorten the time and effort needed to develop customized web-enabled applications for visual analytics or geovisual analytics tasks. Through an atomic layered component architecture, GAV Flash provides a collection of common geo- and information visualization representations extended with motion behavior including scatter matrix, extended parallel coordinates, table lens, choropleth map and treemap, integrated in a multiple, time-linked layout. Versatile interaction methods are drawn from many data visualization research areas and optimized for dynamic web visualization of spatio-temporal and multivariate data. Based on layered component thinking and the use of programming interface mechanism the GAV Flash architecture is open and facilitates the creation of new or improved versions of existing components so that ideas can be tried out or optimized rapidly in a fully functional environment. Following the Visual Analytics mantra, a mechanism "snapshot" for saving the explorative results of a reasoning process is developed that aids collaboration and publication of gained insight and knowledge embedded as dynamic visualizations in blogs or web pages with associative metadata or "storytelling".

  6. Adaptive design of visual perception experiments

    NASA Astrophysics Data System (ADS)

    O'Connor, John D.; Hixson, Jonathan; Thomas, James M., Jr.; Peterson, Matthew S.; Parasuraman, Raja

    2010-04-01

    Meticulous experimental design may not always prevent confounds from affecting experimental data acquired during visual perception experiments. Although experimental controls reduce the potential effects of foreseen sources of interference, interaction, or noise, they are not always adequate for preventing the confounding effects of unforeseen forces. Visual perception experimentation is vulnerable to unforeseen confounds because of the nature of the associated cognitive processes involved in the decision task. Some confounds are beyond the control of experimentation, such as what a participant does immediately prior to experimental participation, or the participant's attitude or emotional state. Other confounds may occur through ignorance of practical control methods on the part of the experiment's designer. The authors conducted experiments related to experimental fatigue and initially achieved significant results that were, upon re-examination, attributable to a lack of adequate controls. Re-examination of the original results and the processes and events that led to them yielded a second experimental design with more experimental controls and significantly different results. The authors propose that designers of visual perception experiments can benefit from planning to use a test-fix-test or adaptive experimental design cycle, so that unforeseen confounds in the initial design can be remedied.

  7. Customizing computational methods for visual analytics with big data.

    PubMed

    Choo, Jaegul; Park, Haesun

    2013-01-01

    The volume of available data has been growing exponentially, increasing data problem's complexity and obscurity. In response, visual analytics (VA) has gained attention, yet its solutions haven't scaled well for big data. Computational methods can improve VA's scalability by giving users compact, meaningful information about the input data. However, the significant computation time these methods require hinders real-time interactive visualization of big data. By addressing crucial discrepancies between these methods and VA regarding precision and convergence, researchers have proposed ways to customize them for VA. These approaches, which include low-precision computation and iteration-level interactive visualization, ensure real-time interactive VA for big data.

  8. An insight-based longitudinal study of visual analytics.

    PubMed

    Saraiya, Purvi; North, Chris; Lam, Vy; Duca, Karen A

    2006-01-01

    Visualization tools are typically evaluated in controlled studies that observe the short-term usage of these tools by participants on preselected data sets and benchmark tasks. Though such studies provide useful suggestions, they miss the long-term usage of the tools. A longitudinal study of a bioinformatics data set analysis is reported here. The main focus of this work is to capture the entire analysis process that an analyst goes through from a raw data set to the insights sought from the data. The study provides interesting observations about the use of visual representations and interaction mechanisms provided by the tools, and also about the process of insight generation in general. This deepens our understanding of visual analytics, guides visualization developers in creating more effective visualization tools in terms of user requirements, and guides evaluators in designing future studies that are more representative of insights sought by users from their data sets.

  9. The Role of Uncertainty, Awareness, and Trust in Visual Analytics.

    PubMed

    Sacha, Dominik; Senaratne, Hansi; Kwon, Bum Chul; Ellis, Geoffrey; Keim, Daniel A

    2016-01-01

    Visual analytics supports humans in generating knowledge from large and often complex datasets. Evidence is collected, collated and cross-linked with our existing knowledge. In the process, a myriad of analytical and visualisation techniques are employed to generate a visual representation of the data. These often introduce their own uncertainties, in addition to the ones inherent in the data, and these propagated and compounded uncertainties can result in impaired decision making. The user's confidence or trust in the results depends on the extent of user's awareness of the underlying uncertainties generated on the system side. This paper unpacks the uncertainties that propagate through visual analytics systems, illustrates how human's perceptual and cognitive biases influence the user's awareness of such uncertainties, and how this affects the user's trust building. The knowledge generation model for visual analytics is used to provide a terminology and framework to discuss the consequences of these aspects in knowledge construction and though examples, machine uncertainty is compared to human trust measures with provenance. Furthermore, guidelines for the design of uncertainty-aware systems are presented that can aid the user in better decision making. PMID:26529704

  10. The top 10 challenges in extreme-scale visual analytics.

    PubMed

    Wong, Pak Chung; Shen, Han-Wei; Johnson, Christopher R; Chen, Chaomei; Ross, Robert B

    2012-01-01

    A team of scientists and researchers discusses the top 10 challenges in extreme-scale visual analytics (VA). The discussion covers applying VA technologies to both scientific and nonscientific data, evaluating the problems and challenges from both technical and social perspectives.

  11. Unlocking proteomic heterogeneity in complex diseases through visual analytics.

    PubMed

    Bhavnani, Suresh K; Dang, Bryant; Bellala, Gowtham; Divekar, Rohit; Visweswaran, Shyam; Brasier, Allan R; Kurosky, Alex

    2015-04-01

    Despite years of preclinical development, biological interventions designed to treat complex diseases such as asthma often fail in phase III clinical trials. These failures suggest that current methods to analyze biomedical data might be missing critical aspects of biological complexity such as the assumption that cases and controls come from homogeneous distributions. Here we discuss why and how methods from the rapidly evolving field of visual analytics can help translational teams (consisting of biologists, clinicians, and bioinformaticians) to address the challenge of modeling and inferring heterogeneity in the proteomic and phenotypic profiles of patients with complex diseases. Because a primary goal of visual analytics is to amplify the cognitive capacities of humans for detecting patterns in complex data, we begin with an overview of the cognitive foundations for the field of visual analytics. Next, we organize the primary ways in which a specific form of visual analytics called networks has been used to model and infer biological mechanisms, which help to identify the properties of networks that are particularly useful for the discovery and analysis of proteomic heterogeneity in complex diseases. We describe one such approach called subject-protein networks, and demonstrate its application on two proteomic datasets. This demonstration provides insights to help translational teams overcome theoretical, practical, and pedagogical hurdles for the widespread use of subject-protein networks for analyzing molecular heterogeneities, with the translational goal of designing biomarker-based clinical trials, and accelerating the development of personalized approaches to medicine.

  12. The Role of Uncertainty, Awareness, and Trust in Visual Analytics.

    PubMed

    Sacha, Dominik; Senaratne, Hansi; Kwon, Bum Chul; Ellis, Geoffrey; Keim, Daniel A

    2016-01-01

    Visual analytics supports humans in generating knowledge from large and often complex datasets. Evidence is collected, collated and cross-linked with our existing knowledge. In the process, a myriad of analytical and visualisation techniques are employed to generate a visual representation of the data. These often introduce their own uncertainties, in addition to the ones inherent in the data, and these propagated and compounded uncertainties can result in impaired decision making. The user's confidence or trust in the results depends on the extent of user's awareness of the underlying uncertainties generated on the system side. This paper unpacks the uncertainties that propagate through visual analytics systems, illustrates how human's perceptual and cognitive biases influence the user's awareness of such uncertainties, and how this affects the user's trust building. The knowledge generation model for visual analytics is used to provide a terminology and framework to discuss the consequences of these aspects in knowledge construction and though examples, machine uncertainty is compared to human trust measures with provenance. Furthermore, guidelines for the design of uncertainty-aware systems are presented that can aid the user in better decision making.

  13. A Visual Analytics Paradigm Enabling Trillion-Edge Graph Exploration

    SciTech Connect

    Wong, Pak C.; Haglin, David J.; Gillen, David S.; Chavarría-Miranda, Daniel; Castellana, Vito G.; Joslyn, Cliff A.; Chappell, Alan R.; Zhang, Song

    2015-07-06

    We present a visual analytics paradigm and a system prototype for exploring web-scale graphs. A web-scale graph is described as a graph with ~one trillion edges and ~50 billion vertices. While there is an aggressive R&D effort in processing and exploring web-scale graphs among internet vendors such as Facebook and Google, visualizing a graph of that scale still remains an underexplored R&D area. The paper describes a nontraditional peek-and-filter strategy that facilitates the exploration of a graph database of unprecedented size for visualization and analytics. We demonstrate that our system prototype can 1) preprocess a graph with ~25 billion edges in less than two hours and 2) support database query and visualization on the processed graph database afterward. Based on our computational performance results, we argue that we most likely will achieve the one trillion edge mark (a computational performance improvement of 40 times) for graph visual analytics in the near future.

  14. Visual analytics in medical education: impacting analytical reasoning and decision making for quality improvement.

    PubMed

    Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

    2015-01-01

    The medical curriculum is the main tool representing the entire undergraduate medical education. Due to its complexity and multilayered structure it is of limited use to teachers in medical education for quality improvement purposes. In this study we evaluated three visualizations of curriculum data from a pilot course, using teachers from an undergraduate medical program and applying visual analytics methods. We found that visual analytics can be used to positively impacting analytical reasoning and decision making in medical education through the realization of variables capable to enhance human perception and cognition on complex curriculum data. The positive results derived from our evaluation of a medical curriculum and in a small scale, signify the need to expand this method to an entire medical curriculum. As our approach sustains low levels of complexity it opens a new promising direction in medical education informatics research.

  15. VACET: Proposed SciDAC2 Visualization and Analytics Center forEnabling Technologies

    SciTech Connect

    Bethel, W.; Johnson, Chris; Hansen, Charles; Parker, Steve; Sanderson, Allen; Silva, Claudio; Tricoche, Xavier; Pascucci, Valerio; Childs, Hank; Cohen, Jonathon; Duchaineau, Mark; Laney, Dan; Lindstrom,Peter; Ahern, Sean; Meredith, Jeremy; Ostrouchov, George; Joy, Ken; Hamann, Bernd

    2006-06-19

    This paper accompanies a poster that is being presented atthe SciDAC 2006 meeting in Denver, CO. This project focuses on leveragingscientific visualization and analytics software technology as an enablingtechnology for increasing scientific productivity and insight. Advancesincomputational technology have resultedin an "information big bang,"which in turn has createda significant data understanding challenge. Thischallenge is widely acknowledged to be one of the primary bottlenecks incontemporary science. The vision for our Center is to respond directly tothat challenge by adapting, extending, creating when necessary anddeploying visualization and data understanding technologies for ourscience stakeholders. Using an organizational model as a Visualizationand Analytics Center for Enabling Technologies (VACET), we are wellpositioned to be responsive to the needs of a diverse set of scientificstakeholders in a coordinated fashion using a range of visualization,mathematics, statistics, computer and computational science and datamanagement technologies.

  16. Transmission Line Adapted Analytical Power Charts Solution

    NASA Astrophysics Data System (ADS)

    Sakala, Japhet D.; Daka, James S. J.; Setlhaolo, Ditiro; Malichi, Alec Pulu

    2016-08-01

    The performance of a transmission line has been assessed over the years using power charts. These are graphical representations, drawn to scale, of the equations that describe the performance of transmission lines. Various quantities that describe the performance, such as sending end voltage, sending end power and compensation to give zero voltage regulation, may be deduced from the power charts. Usually required values are read off and then converted using the appropriate scales and known relationships. In this paper, the authors revisit this area of circle diagrams for transmission line performance. The work presented here formulates the mathematical model that analyses the transmission line performance from the power charts relationships and then uses them to calculate the transmission line performance. In this proposed approach, it is not necessary to draw the power charts for the solution. However the power charts may be drawn for the visual presentation. The method is based on applying derived equations and is simple to use since it does not require rigorous derivations.

  17. GenoSets: Visual Analytic Methods for Comparative Genomics

    PubMed Central

    Cain, Aurora A.; Kosara, Robert; Gibas, Cynthia J.

    2012-01-01

    Many important questions in biology are, fundamentally, comparative, and this extends to our analysis of a growing number of sequenced genomes. Existing genomic analysis tools are often organized around literal views of genomes as linear strings. Even when information is highly condensed, these views grow cumbersome as larger numbers of genomes are added. Data aggregation and summarization methods from the field of visual analytics can provide abstracted comparative views, suitable for sifting large multi-genome datasets to identify critical similarities and differences. We introduce a software system for visual analysis of comparative genomics data. The system automates the process of data integration, and provides the analysis platform to identify and explore features of interest within these large datasets. GenoSets borrows techniques from business intelligence and visual analytics to provide a rich interface of interactive visualizations supported by a multi-dimensional data warehouse. In GenoSets, visual analytic approaches are used to enable querying based on orthology, functional assignment, and taxonomic or user-defined groupings of genomes. GenoSets links this information together with coordinated, interactive visualizations for both detailed and high-level categorical analysis of summarized data. GenoSets has been designed to simplify the exploration of multiple genome datasets and to facilitate reasoning about genomic comparisons. Case examples are included showing the use of this system in the analysis of 12 Brucella genomes. GenoSets software and the case study dataset are freely available at http://genosets.uncc.edu. We demonstrate that the integration of genomic data using a coordinated multiple view approach can simplify the exploration of large comparative genomic data sets, and facilitate reasoning about comparisons and features of interest. PMID:23056299

  18. GenoSets: visual analytic methods for comparative genomics.

    PubMed

    Cain, Aurora A; Kosara, Robert; Gibas, Cynthia J

    2012-01-01

    Many important questions in biology are, fundamentally, comparative, and this extends to our analysis of a growing number of sequenced genomes. Existing genomic analysis tools are often organized around literal views of genomes as linear strings. Even when information is highly condensed, these views grow cumbersome as larger numbers of genomes are added. Data aggregation and summarization methods from the field of visual analytics can provide abstracted comparative views, suitable for sifting large multi-genome datasets to identify critical similarities and differences. We introduce a software system for visual analysis of comparative genomics data. The system automates the process of data integration, and provides the analysis platform to identify and explore features of interest within these large datasets. GenoSets borrows techniques from business intelligence and visual analytics to provide a rich interface of interactive visualizations supported by a multi-dimensional data warehouse. In GenoSets, visual analytic approaches are used to enable querying based on orthology, functional assignment, and taxonomic or user-defined groupings of genomes. GenoSets links this information together with coordinated, interactive visualizations for both detailed and high-level categorical analysis of summarized data. GenoSets has been designed to simplify the exploration of multiple genome datasets and to facilitate reasoning about genomic comparisons. Case examples are included showing the use of this system in the analysis of 12 Brucella genomes. GenoSets software and the case study dataset are freely available at http://genosets.uncc.edu. We demonstrate that the integration of genomic data using a coordinated multiple view approach can simplify the exploration of large comparative genomic data sets, and facilitate reasoning about comparisons and features of interest.

  19. SnapShot: Visualization to Propel Ice Hockey Analytics.

    PubMed

    Pileggi, H; Stolper, C D; Boyle, J M; Stasko, J T

    2012-12-01

    Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel.

  20. VisOHC: Designing Visual Analytics for Online Health Communities

    PubMed Central

    Kwon, Bum Chul; Kim, Sung-Hee; Lee, Sukwon; Choo, Jaegul; Huh, Jina; Yi, Ji Soo

    2015-01-01

    Through online health communities (OHCs), patients and caregivers exchange their illness experiences and strategies for overcoming the illness, and provide emotional support. To facilitate healthy and lively conversations in these communities, their members should be continuously monitored and nurtured by OHC administrators. The main challenge of OHC administrators' tasks lies in understanding the diverse dimensions of conversation threads that lead to productive discussions in their communities. In this paper, we present a design study in which three domain expert groups participated, an OHC researcher and two OHC administrators of online health communities, which was conducted to find with a visual analytic solution. Through our design study, we characterized the domain goals of OHC administrators and derived tasks to achieve these goals. As a result of this study, we propose a system called VisOHC, which visualizes individual OHC conversation threads as collapsed boxes–a visual metaphor of conversation threads. In addition, we augmented the posters' reply authorship network with marks and/or beams to show conversation dynamics within threads. We also developed unique measures tailored to the characteristics of OHCs, which can be encoded for thread visualizations at the users' requests. Our observation of the two administrators while using VisOHC showed that it supports their tasks and reveals interesting insights into online health communities. Finally, we share our methodological lessons on probing visual designs together with domain experts by allowing them to freely encode measurements into visual variables. PMID:26529688

  1. VisOHC: Designing Visual Analytics for Online Health Communities.

    PubMed

    Kwon, Bum Chul; Kim, Sung-Hee; Lee, Sukwon; Choo, Jaegul; Huh, Jina; Yi, Ji Soo

    2016-01-01

    Through online health communities (OHCs), patients and caregivers exchange their illness experiences and strategies for overcoming the illness, and provide emotional support. To facilitate healthy and lively conversations in these communities, their members should be continuously monitored and nurtured by OHC administrators. The main challenge of OHC administrators' tasks lies in understanding the diverse dimensions of conversation threads that lead to productive discussions in their communities. In this paper, we present a design study in which three domain expert groups participated, an OHC researcher and two OHC administrators of online health communities, which was conducted to find with a visual analytic solution. Through our design study, we characterized the domain goals of OHC administrators and derived tasks to achieve these goals. As a result of this study, we propose a system called VisOHC, which visualizes individual OHC conversation threads as collapsed boxes-a visual metaphor of conversation threads. In addition, we augmented the posters' reply authorship network with marks and/or beams to show conversation dynamics within threads. We also developed unique measures tailored to the characteristics of OHCs, which can be encoded for thread visualizations at the users' requests. Our observation of the two administrators while using VisOHC showed that it supports their tasks and reveals interesting insights into online health communities. Finally, we share our methodological lessons on probing visual designs together with domain experts by allowing them to freely encode measurements into visual variables.

  2. Visual analytics for model selection in time series analysis.

    PubMed

    Bögl, Markus; Aigner, Wolfgang; Filzmoser, Peter; Lammarsch, Tim; Miksch, Silvia; Rind, Alexander

    2013-12-01

    Model selection in time series analysis is a challenging task for domain experts in many application areas such as epidemiology, economy, or environmental sciences. The methodology used for this task demands a close combination of human judgement and automated computation. However, statistical software tools do not adequately support this combination through interactive visual interfaces. We propose a Visual Analytics process to guide domain experts in this task. For this purpose, we developed the TiMoVA prototype that implements this process based on user stories and iterative expert feedback on user experience. The prototype was evaluated by usage scenarios with an example dataset from epidemiology and interviews with two external domain experts in statistics. The insights from the experts' feedback and the usage scenarios show that TiMoVA is able to support domain experts in model selection tasks through interactive visual interfaces with short feedback cycles.

  3. Immersive Visual Analytics for Transformative Neutron Scattering Science

    SciTech Connect

    Steed, Chad A; Daniel, Jamison R; Drouhard, Margaret; Hahn, Steven E; Proffen, Thomas E

    2016-01-01

    The ORNL Spallation Neutron Source (SNS) provides the most intense pulsed neutron beams in the world for scientific research and development across a broad range of disciplines. SNS experiments produce large volumes of complex data that are analyzed by scientists with varying degrees of experience using 3D visualization and analysis systems. However, it is notoriously difficult to achieve proficiency with 3D visualizations. Because 3D representations are key to understanding the neutron scattering data, scientists are unable to analyze their data in a timely fashion resulting in inefficient use of the limited and expensive SNS beam time. We believe a more intuitive interface for exploring neutron scattering data can be created by combining immersive virtual reality technology with high performance data analytics and human interaction. In this paper, we present our initial investigations of immersive visualization concepts as well as our vision for an immersive visual analytics framework that could lower the barriers to 3D exploratory data analysis of neutron scattering data at the SNS.

  4. Distributed visual analytics for collaborative emergency response management.

    PubMed

    Natarajan, Sriram; Ganz, Aura

    2009-01-01

    In emergency response management, there is a large volume of incoming data and minimal time to process it before making critical decisions. Multiple experts, physicians, incident commander who are geographically distributed, collaboratively work on the collected data to make efficient and timely decisions. In this paper we introduce a distributed visualization environment that supports collaboration among geographically dispersed users. To achieve synchronized update among multiple users we introduce a group synchronization technique which employs an adaptive time adjusting algorithm to modify the output time of the visualization unit. In order to evaluate our system we have developed an interactive synchronous visualization unit, and tested our work by running it on varying network delay collaborative servers and achieve time synchronization among them.

  5. Facilitating the Analysis of Immunological Data with Visual Analytic Techniques

    PubMed Central

    Shih, David C.; Ho, Kevin C.; Melnick, Kyle M.; Rensink, Ronald A.; Kollmann, Tobias R.; Fortuno III, Edgardo S.

    2011-01-01

    Visual analytics (VA) has emerged as a new way to analyze large dataset through interactive visual display. We demonstrated the utility and the flexibility of a VA approach in the analysis of biological datasets. Examples of these datasets in immunology include flow cytometry, Luminex data, and genotyping (e.g., single nucleotide polymorphism) data. Contrary to the traditional information visualization approach, VA restores the analysis power in the hands of analyst by allowing the analyst to engage in real-time data exploration process. We selected the VA software called Tableau after evaluating several VA tools. Two types of analysis tasks analysis within and between datasets were demonstrated in the video presentation using an approach called paired analysis. Paired analysis, as defined in VA, is an analysis approach in which a VA tool expert works side-by-side with a domain expert during the analysis. The domain expert is the one who understands the significance of the data, and asks the questions that the collected data might address. The tool expert then creates visualizations to help find patterns in the data that might answer these questions. The short lag-time between the hypothesis generation and the rapid visual display of the data is the main advantage of a VA approach. PMID:21248691

  6. Facilitating the analysis of immunological data with visual analytic techniques.

    PubMed

    Shih, David C; Ho, Kevin C; Melnick, Kyle M; Rensink, Ronald A; Kollmann, Tobias R; Fortuno, Edgardo S

    2011-01-02

    Visual analytics (VA) has emerged as a new way to analyze large dataset through interactive visual display. We demonstrated the utility and the flexibility of a VA approach in the analysis of biological datasets. Examples of these datasets in immunology include flow cytometry, Luminex data, and genotyping (e.g., single nucleotide polymorphism) data. Contrary to the traditional information visualization approach, VA restores the analysis power in the hands of analyst by allowing the analyst to engage in real-time data exploration process. We selected the VA software called Tableau after evaluating several VA tools. Two types of analysis tasks analysis within and between datasets were demonstrated in the video presentation using an approach called paired analysis. Paired analysis, as defined in VA, is an analysis approach in which a VA tool expert works side-by-side with a domain expert during the analysis. The domain expert is the one who understands the significance of the data, and asks the questions that the collected data might address. The tool expert then creates visualizations to help find patterns in the data that might answer these questions. The short lag-time between the hypothesis generation and the rapid visual display of the data is the main advantage of a VA approach.

  7. Big Data Visual Analytics for Exploratory Earth System Simulation Analysis

    SciTech Connect

    Steed, Chad A.; Ricciuto, Daniel M.; Shipman, Galen M.; Smith, Brian E.; Thornton, Peter E.; Wang, Dali; Shi, Xiaoying; Williams, Dean N.

    2013-12-01

    Rapid increases in high performance computing are feeding the development of larger and more complex data sets in climate research, which sets the stage for so-called big data analysis challenges. However, conventional climate analysis techniques are inadequate in dealing with the complexities of today s data. In this paper, we describe and demonstrate a visual analytics system, called the Exploratory Data analysis ENvironment (EDEN), with specific application to the analysis of complex earth system simulation data sets. EDEN represents the type of interactive visual analysis tools that are necessary to transform data into insight, thereby improving critical comprehension of earth system processes. In addition to providing an overview of EDEN, we describe real-world studies using both point ensembles and global Community Land Model Version 4 (CLM4) simulations.

  8. A Visual Analytics Approach for Correlation, Classification, and Regression Analysis

    SciTech Connect

    Steed, Chad A; SwanII, J. Edward; Fitzpatrick, Patrick J.; Jankun-Kelly, T.J.

    2013-01-01

    New approaches that combine the strengths of humans and machines are necessary to equip analysts with the proper tools for exploring today s increasing complex, multivariate data sets. In this paper, a visual data mining framework, called the Multidimensional Data eXplorer (MDX), is described that addresses the challenges of today s data by combining automated statistical analytics with a highly interactive parallel coordinates based canvas. In addition to several intuitive interaction capabilities, this framework offers a rich set of graphical statistical indicators, interactive regression analysis, visual correlation mining, automated axis arrangements and filtering, and data classification techniques. This chapter provides a detailed description of the system as well as a discussion of key design aspects and critical feedback from domain experts.

  9. WebTheme: Understanding Web Information through Visual Analytics

    SciTech Connect

    Whiting, Mark A.; Cramer, Nicholas O.

    2002-06-09

    WebTheme combines the power of software agent-based information retrieval with visual analytics to provide users with a new tool for understanding web information. WebTheme allows users to both quickly comprehend large collections of information from the Web and drill down into interesting portions of a collection. Software agents work for users to perform controlled harvesting of web material of interest. Visualization and analysis tools allow exploration of the resulting document space. Information spaces are organized and presented according to their topical context. Tools that display how documents were collected by the agents, where they were gathered, and how they are linked further enhance users? understanding of information and its context. WebTheme is a significant tool in the pursuit of the Semantic Web. In particular, it supports enhanced user insight into semantics of large, pre-structured or ad-hoc, web information collections.

  10. Using Visual Analytics to Maintain Situation Awareness in Astrophysics

    SciTech Connect

    Aragon, Cecilia R.; Poon, Sarah S.; Aldering, Gregory S.; Thomas, Rollin C.; Quimby, Robert

    2008-07-01

    We present a novel collaborative visual analytics application for cognitively overloaded users in the astrophysics domain. The system was developed for scientists needing to analyze heterogeneous, complex data under time pressure, and then make predictions and time-critical decisions rapidly and correctly under a constant influx of changing data. The Sunfall Data Taking system utilizes severalnovel visualization and analysis techniques to enable a team of geographically distributed domain specialists to effectively and remotely maneuver a custom-built instrument under challenging operational conditions. Sunfall Data Taking has been in use for over eighteen months by a major international astrophysics collaboration (the largest data volume supernova search currently in operation), and has substantially improved the operational efficiency of its users. We describe the system design process by an interdisciplinary team, the system architecture, and the results of an informal usability evaluation of the production system by domain experts in the context of Endsley?s three levels of situation awareness.

  11. A Visual Analytics Approach for Correlation, Classification, and Regression Analysis

    SciTech Connect

    Steed, Chad A; SwanII, J. Edward; Fitzpatrick, Patrick J.; Jankun-Kelly, T.J.

    2012-02-01

    New approaches that combine the strengths of humans and machines are necessary to equip analysts with the proper tools for exploring today's increasing complex, multivariate data sets. In this paper, a novel visual data mining framework, called the Multidimensional Data eXplorer (MDX), is described that addresses the challenges of today's data by combining automated statistical analytics with a highly interactive parallel coordinates based canvas. In addition to several intuitive interaction capabilities, this framework offers a rich set of graphical statistical indicators, interactive regression analysis, visual correlation mining, automated axis arrangements and filtering, and data classification techniques. The current work provides a detailed description of the system as well as a discussion of key design aspects and critical feedback from domain experts.

  12. A visual-analytics system for railway safety management.

    PubMed

    Lira, Wallace P; Alves, Ronnie; Costa, Jean M R; Pessin, Gustavo; Galvao, Lilyan; Cardoso, Ana C; de Souza, Cleidson R B

    2014-01-01

    The working environment of railways is challenging and complex and often involves high-risk operations. These operations affect both the company staff and inhabitants of the towns and cities alongside the railway lines. To reduce the employees' and public's exposure to risk, railway companies adopt strategies involving trained safety personnel, advanced forms of technology, and special work processes. Nevertheless, unfortunate incidents still occur. To assist railway safety management, researchers developed a visual-analytics system. Using a data analytics workflow, it compiles an incident risk index that processes information about railway incidents. It displays the index on a geographical map, together with socioeconomic information about the associated towns and cities. Feedback on this system suggests that safety engineers and experts can use it to make and communicate decisions.

  13. Visualizing 3D Turbulence On Temporally Adaptive Wavelet Collocation Grids

    NASA Astrophysics Data System (ADS)

    Goldstein, D. E.; Kadlec, B. J.; Yuen, D. A.; Erlebacher, G.

    2005-12-01

    Today there is an explosion in data from high-resolution computations of nonlinear phenomena in many fields, including the geo- and environmental sciences. The efficient storage and subsequent visualization of these large data sets is a trade off in storage costs versus data quality. New dynamically adaptive simulation methodologies promise significant computational cost savings and have the added benefit of producing results on adapted grids that significantly reduce storage and data manipulation costs. Yet, with these adaptive simulation methodologies come new challenges in the visualization of temporally adaptive data sets. In this work turbulence data sets from Stochastic Coherent Adaptive Large Eddy Simulations (SCALES) are visualized with the open source tool ParaView, as a challenging case study. SCALES simulations use a temporally adaptive collocation grid defined by wavelet threshold filtering to resolve the most energetic coherent structures in a turbulence field. A subgrid scale model is used to account for the effect of unresolved subgrid scale modes. The results from the SCALES simulations are saved on a thresholded dyadic wavelet collocation grid, which by its nature does not include cell information. Paraview is an open source visualization package developed by KitWare(tm) that is based on the widely used VTK graphics toolkit. The efficient generation of cell information, required with current ParaView data formats, is explored using custom algorithms and VTK toolkit routines. Adaptive 3d visualizations using isosurfaces and volume visualizations are compared with non-adaptive visualizations. To explore the localized multiscale structures in the turbulent data sets the wavelet coefficients are also visualized allowing visualization of energy contained in local physical regions as well as in local wave number space.

  14. Integrated genome browser: visual analytics platform for genomics

    PubMed Central

    Norris, David C.; Loraine, Ann E.

    2016-01-01

    Motivation: Genome browsers that support fast navigation through vast datasets and provide interactive visual analytics functions can help scientists achieve deeper insight into biological systems. Toward this end, we developed Integrated Genome Browser (IGB), a highly configurable, interactive and fast open source desktop genome browser. Results: Here we describe multiple updates to IGB, including all-new capabilities to display and interact with data from high-throughput sequencing experiments. To demonstrate, we describe example visualizations and analyses of datasets from RNA-Seq, ChIP-Seq and bisulfite sequencing experiments. Understanding results from genome-scale experiments requires viewing the data in the context of reference genome annotations and other related datasets. To facilitate this, we enhanced IGB’s ability to consume data from diverse sources, including Galaxy, Distributed Annotation and IGB-specific Quickload servers. To support future visualization needs as new genome-scale assays enter wide use, we transformed the IGB codebase into a modular, extensible platform for developers to create and deploy all-new visualizations of genomic data. Availability and implementation: IGB is open source and is freely available from http://bioviz.org/igb. Contact: aloraine@uncc.edu PMID:27153568

  15. Incremental visual text analytics of news story development

    NASA Astrophysics Data System (ADS)

    Krstajic, Milos; Najm-Araghi, Mohammad; Mansmann, Florian; Keim, Daniel A.

    2012-01-01

    Online news sources produce thousands of news articles every day, reporting on local and global real-world events. New information quickly replaces the old, making it difficult for readers to put current events in the context of the past. Additionally, the stories have very complex relationships and characteristics that are difficult to model: they can be weakly or strongly connected, or they can merge or split over time. In this paper, we present a visual analytics system for exploration of news topics in dynamic information streams, which combines interactive visualization and text mining techniques to facilitate the analysis of similar topics that split and merge over time. We employ text clustering techniques to automatically extract stories from online news streams and present a visualization that: 1) shows temporal characteristics of stories in different time frames with different level of detail; 2) allows incremental updates of the display without recalculating the visual features of the past data; 3) sorts the stories by minimizing clutter and overlap from edge crossings. By using interaction, stories can be filtered based on their duration and characteristics in order to be explored in full detail with details on demand. To demonstrate the usefulness of our system, case studies with real news data are presented and show the capabilities for detailed dynamic text stream exploration.

  16. T.Rex Visual Analytics for Transactional Exploration

    SciTech Connect

    2014-07-01

    T.Rex is PNNL's visual analytics tool that specializes in tabular structured data, like you might open with Excel. It's a client-server application, allowing the server to do a lot of the heavy lifting and the client to open spreadsheets with millions of rows. With datasets of that size, especially if you're unfamiliar with the contents, it's very hard to get a good grasp of what's in it using traditional tools. With T.Rex, the multiple views allow you to see categorical, temporal, numerical, relational, and summary data. The interactivity lets you look across your data and see how things relate to each other.

  17. T.Rex Visual Analytics for Transactional Exploration

    ScienceCinema

    None

    2016-07-12

    T.Rex is PNNL's visual analytics tool that specializes in tabular structured data, like you might open with Excel. It's a client-server application, allowing the server to do a lot of the heavy lifting and the client to open spreadsheets with millions of rows. With datasets of that size, especially if you're unfamiliar with the contents, it's very hard to get a good grasp of what's in it using traditional tools. With T.Rex, the multiple views allow you to see categorical, temporal, numerical, relational, and summary data. The interactivity lets you look across your data and see how things relate to each other.

  18. Adaptive changes in visual cortex following prolonged contrast reduction

    PubMed Central

    Kwon, MiYoung; Legge, Gordon E.; Fang, Fang; Cheong, Allen M. Y.; He, Sheng

    2009-01-01

    How does prolonged reduction in retinal-image contrast affect visual-contrast coding? Recent evidence indicates that some forms of long-term visual deprivation result in compensatory perceptual and neural changes in the adult visual pathway. It has not been established whether changes due to contrast adaptation are best characterized as “contrast gain” or “response gain.” We present a theoretical rationale for predicting that adaptation to long-term contrast reduction should result in response gain. To test this hypothesis, normally sighted subjects adapted for four hours by viewing their environment through contrast-reducing goggles. During the adaptation period, the subjects went about their usual daily activities. Subjects' contrast-discrimination thresholds and fMRI BOLD responses in cortical areas V1 and V2 were obtained before and after adaptation. Following adaptation, we observed a significant decrease in contrast-discrimination thresholds, and significant increase in BOLD responses in V1 and V2. The observed interocular transfer of the adaptation effect suggests that the adaptation has a cortical origin. These results reveal a new kind of adaptability of the adult visual cortex, an adjustment in the gain of the contrast-response in the presence of a reduced range of stimulus contrasts, which is consistent with a response-gain mechanism. The adaptation appears to be compensatory, such that the precision of contrast coding is improved for low retinal-image contrasts. PMID:19271930

  19. An extensible framework for provenance in human terrain visual analytics.

    PubMed

    Walker, Rick; Slingsby, Aiden; Dykes, Jason; Xu, Kai; Wood, Jo; Nguyen, Phong H; Stephens, Derek; Wong, B L William; Zheng, Yongjun

    2013-12-01

    We describe and demonstrate an extensible framework that supports data exploration and provenance in the context of Human Terrain Analysis (HTA). Working closely with defence analysts we extract requirements and a list of features that characterise data analysed at the end of the HTA chain. From these, we select an appropriate non-classified data source with analogous features, and model it as a set of facets. We develop ProveML, an XML-based extension of the Open Provenance Model, using these facets and augment it with the structures necessary to record the provenance of data, analytical process and interpretations. Through an iterative process, we develop and refine a prototype system for Human Terrain Visual Analytics (HTVA), and demonstrate means of storing, browsing and recalling analytical provenance and process through analytic bookmarks in ProveML. We show how these bookmarks can be combined to form narratives that link back to the live data. Throughout the process, we demonstrate that through structured workshops, rapid prototyping and structured communication with intelligence analysts we are able to establish requirements, and design schema, techniques and tools that meet the requirements of the intelligence community. We use the needs and reactions of defence analysts in defining and steering the methods to validate the framework.

  20. Image Watermarking Based on Adaptive Models of Human Visual Perception

    NASA Astrophysics Data System (ADS)

    Khawne, Amnach; Hamamoto, Kazuhiko; Chitsobhuk, Orachat

    This paper proposes a digital image watermarking based on adaptive models of human visual perception. The algorithm exploits the local activities estimated from wavelet coefficients of each subband to adaptively control the luminance masking. The adaptive luminance is thus delicately combined with the contrast masking and edge detection and adopted as a visibility threshold. With the proposed combination of adaptive visual sensitivity parameters, the proposed perceptual model can be more appropriate to the different characteristics of various images. The weighting function is chosen such that the fidelity, imperceptibility and robustness could be preserved without making any perceptual difference to the image quality.

  1. Decision exploration lab: a visual analytics solution for decision management.

    PubMed

    Broeksema, Bertjan; Baudel, Thomas; Telea, Arthur G; Crisafulli, Paolo

    2013-12-01

    We present a visual analytics solution designed to address prevalent issues in the area of Operational Decision Management (ODM). In ODM, which has its roots in Artificial Intelligence (Expert Systems) and Management Science, it is increasingly important to align business decisions with business goals. In our work, we consider decision models (executable models of the business domain) as ontologies that describe the business domain, and production rules that describe the business logic of decisions to be made over this ontology. Executing a decision model produces an accumulation of decisions made over time for individual cases. We are interested, first, to get insight in the decision logic and the accumulated facts by themselves. Secondly and more importantly, we want to see how the accumulated facts reveal potential divergences between the reality as captured by the decision model, and the reality as captured by the executed decisions. We illustrate the motivation, added value for visual analytics, and our proposed solution and tooling through a business case from the car insurance industry.

  2. Visual Cues for an Adaptive Expert System.

    ERIC Educational Resources Information Center

    Miller, Helen B.

    NCR (National Cash Register) Corporation is pursuing opportunities to make their point of sale (POS) terminals easy to use and easy to learn. To approach the goal of making the technology invisible to the user, NCR has developed an adaptive expert prototype system for a department store POS operation. The structure for the adaptive system, the…

  3. Visual Bias Predicts Gait Adaptability in Novel Sensory Discordant Conditions

    NASA Technical Reports Server (NTRS)

    Brady, Rachel A.; Batson, Crystal D.; Peters, Brian T.; Mulavara, Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    We designed a gait training study that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their postural stability and cognitive performance in a new discordant environment presented at the conclusion of training (Transfer Test). Our training system comprised a treadmill placed on a motion base facing a virtual visual scene that provided a variety of sensory challenges. Ten healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. At the first visit, in an analysis of normalized torso translation measured in a scene-movement-only condition, 3 of 10 subjects were classified as visually dependent. During the Transfer Test, all participants received a 2-minute novel exposure. In a combined measure of stride frequency and reaction time, the non-visually dependent subjects showed improved adaptation on the Transfer Test compared to their visually dependent counterparts. This finding suggests that individual differences in the ability to adapt to new sensorimotor conditions may be explained by individuals innate sensory biases. An accurate preflight assessment of crewmembers biases for visual dependence could be used to predict their propensities to adapt to novel sensory conditions. It may also facilitate the development of customized training regimens that could expedite adaptation to alternate gravitational environments.

  4. Reliance on visual attention during visuomotor adaptation: an SSVEP study.

    PubMed

    Reuter, Eva-Maria; Bednark, Jeffery; Cunnington, Ross

    2015-07-01

    Visuomotor adaptation involves the learning of a new mapping between a spatial goal and well-learned movements. In order to learn a new visuomotor transformation, visual attention is needed to monitor movements and their visual consequences. Once a transformation is learnt, it can be executed automatically without attentional control. Using steady-state visual evoked potentials (SSVEPs) measured from EEG activity, we examined how visual attention changes during the early phase of visuomotor adaptation. SSVEPs were elicited by a green disc flickering at 15 Hz which was either the movement target or the cursor that participants controlled. Participants performed an adapted continuous visuomotor adaptation task with either 60° or 120° screen cursor rotation, and changes in 15-Hz SSVEP power were examined. Participants' performance improved over time in all conditions, with the rate of learning significantly influenced by the degree of rotation. SSVEPs at 15 Hz showed a significant change over time with adaptation for 60° rotations, but not for 120° rotations, such that SSVEPs elicited by the stimuli were significantly lower for 60° compared with 120° rotation conditions over the last adaptation blocks. This suggests that visual attention to the movement target and feedback reduces over time as performance improves during visuomotor adaptation for easier rotations, but must be maintained throughout the task for more difficult 120° rotations that might require more strategic control.

  5. Visual analytics for discovering node groups in complex networks

    NASA Astrophysics Data System (ADS)

    Nishikawa, Takashi

    2011-03-01

    Given the abundance of relational data from a variety of sources, it is becoming increasingly more important to be able to discover hidden structures in the topology of real-world complex networks. In this talk, I will extend the usual definition of groups as densely connected sets of nodes and show that many real networks have groups distinguished by a diverse combinations of node properties, but not by the density of links alone. To overcome the virtually unlimited ways to potentially distinguish groups, we have developed an exploratory analysis tool that exploit human visual ability. In this visual analytical approach, the user input from visual interaction is integrated into the analysis to discover unknown group structures, rather than simply detecting a known type of structure. I will also address the problem of determining an appropriate number of groups, when it is not known a priori. I will demonstrate that our method can effectively find and characterize a variety of group structures in model and real-world networks, including community and k -partite structures defined by link density, as well as groups distinguished by combinations of other node properties. Funded by FODAVA NSF-DMS-0808860.

  6. Evaluation of Visual Analytics Environments: The Road to the Visual Analytics Science and Technology Challenge Evaluation Methodology

    SciTech Connect

    Scholtz, Jean; Plaisant, Catherine; Whiting, Mark A.; Grinstein, Georges

    2014-09-28

    The evaluation of visual analytics environments was a topic in Illuminating the Path [Thomas 2005] as a critical aspect of moving research into practice. For a thorough understanding of the utility of the systems available, evaluation not only involves assessing the visualizations, interactions or data processing algorithms themselves, but also the complex processes that a tool is meant to support (such as exploratory data analysis and reasoning, communication through visualization, or collaborative data analysis [Lam 2012; Carpendale 2007]). Researchers and practitioners in the field have long identified many of the challenges faced when planning, conducting, and executing an evaluation of a visualization tool or system [Plaisant 2004]. Evaluation is needed to verify that algorithms and software systems work correctly and that they represent improvements over the current infrastructure. Additionally to effectively transfer new software into a working environment, it is necessary to ensure that the software has utility for the end-users and that the software can be incorporated into the end-user’s infrastructure and work practices. Evaluation test beds require datasets, tasks, metrics and evaluation methodologies. As noted in [Thomas 2005] it is difficult and expensive for any one researcher to setup an evaluation test bed so in many cases evaluation is setup for communities of researchers or for various research projects or programs. Examples of successful community evaluations can be found [Chinchor 1993; Voorhees 2007; FRGC 2012]. As visual analytics environments are intended to facilitate the work of human analysts, one aspect of evaluation needs to focus on the utility of the software to the end-user. This requires representative users, representative tasks, and metrics that measure the utility to the end-user. This is even more difficult as now one aspect of the test methodology is access to representative end-users to participate in the evaluation. In many

  7. Hour-long adaptation in the awake early visual system

    PubMed Central

    Stoelzel, Carl R.; Huff, Joseph M.; Bereshpolova, Yulia; Zhuang (庄骏), Jun; Hei (黑晓娟), Xiaojuan; Alonso, Jose-Manuel

    2015-01-01

    Sensory adaptation serves to adjust awake brains to changing environments on different time scales. However, adaptation has been studied traditionally under anesthesia and for short time periods. Here, we demonstrate in awake rabbits a novel type of sensory adaptation that persists for >1 h and acts on visual thalamocortical neurons and their synapses in the input layers of the visual cortex. Following prolonged visual stimulation (10–30 min), cells in the dorsal lateral geniculate nucleus (LGN) show a severe and prolonged reduction in spontaneous firing rate. This effect is bidirectional, and prolonged visually induced response suppression is followed by a prolonged increase in spontaneous activity. The reduction in thalamic spontaneous activity following prolonged visual activation is accompanied by increases in 1) response reliability, 2) signal detectability, and 3) the ratio of visual signal/spontaneous activity. In addition, following such prolonged activation of an LGN neuron, the monosynaptic currents generated by thalamic impulses in layer 4 of the primary visual cortex are enhanced. These results demonstrate that in awake brains, prolonged sensory stimulation can have a profound, long-lasting effect on the information conveyed by thalamocortical inputs to the visual cortex. PMID:26108950

  8. Visual adaptation provides objective electrophysiological evidence of facial identity discrimination.

    PubMed

    Retter, Talia L; Rossion, Bruno

    2016-07-01

    Discrimination of facial identities is a fundamental function of the human brain that is challenging to examine with macroscopic measurements of neural activity, such as those obtained with functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). Although visual adaptation or repetition suppression (RS) stimulation paradigms have been successfully implemented to this end with such recording techniques, objective evidence of an identity-specific discrimination response due to adaptation at the level of the visual representation is lacking. Here, we addressed this issue with fast periodic visual stimulation (FPVS) and EEG recording combined with a symmetry/asymmetry adaptation paradigm. Adaptation to one facial identity is induced through repeated presentation of that identity at a rate of 6 images per second (6 Hz) over 10 sec. Subsequently, this identity is presented in alternation with another facial identity (i.e., its anti-face, both faces being equidistant from an average face), producing an identity repetition rate of 3 Hz over a 20 sec testing sequence. A clear EEG response at 3 Hz is observed over the right occipito-temporal (ROT) cortex, indexing discrimination between the two facial identities in the absence of an explicit behavioral discrimination measure. This face identity discrimination occurs immediately after adaptation and disappears rapidly within 20 sec. Importantly, this 3 Hz response is not observed in a control condition without the single-identity 10 sec adaptation period. These results indicate that visual adaptation to a given facial identity produces an objective (i.e., at a pre-defined stimulation frequency) electrophysiological index of visual discrimination between that identity and another, and provides a unique behavior-free quantification of the effect of visual adaptation.

  9. A visual analytics approach to understanding spatiotemporal hotspots.

    PubMed

    Maciejewski, Ross; Rudolph, Stephen; Hafen, Ryan; Abusalah, Ahmad M; Yakout, Mohamed; Ouzzani, Mourad; Cleveland, William S; Grannis, Shaun J; Ebert, David S

    2010-01-01

    As data sources become larger and more complex, the ability to effectively explore and analyze patterns among varying sources becomes a critical bottleneck in analytic reasoning. Incoming data contain multiple variables, high signal-to-noise ratio, and a degree of uncertainty, all of which hinder exploration, hypothesis generation/exploration, and decision making. To facilitate the exploration of such data, advanced tool sets are needed that allow the user to interact with their data in a visual environment that provides direct analytic capability for finding data aberrations or hotspots. In this paper, we present a suite of tools designed to facilitate the exploration of spatiotemporal data sets. Our system allows users to search for hotspots in both space and time, combining linked views and interactive filtering to provide users with contextual information about their data and allow the user to develop and explore their hypotheses. Statistical data models and alert detection algorithms are provided to help draw user attention to critical areas. Demographic filtering can then be further applied as hypotheses generated become fine tuned. This paper demonstrates the use of such tools on multiple geospatiotemporal data sets.

  10. Tracking nonstationary visual appearances by data-driven adaptation.

    PubMed

    Yang, Ming; Fan, Zhimin; Fan, Jialue; Wu, Ying

    2009-07-01

    Without any prior about the target, the appearance is usually the only cue available in visual tracking. However, in general, the appearances are often nonstationary which may ruin the predefined visual measurements and often lead to tracking failure in practice. Thus, a natural solution is to adapt the observation model to the nonstationary appearances. However, this idea is threatened by the risk of adaptation drift that originates in its ill-posed nature, unless good data-driven constraints are imposed. Different from most existing adaptation schemes, we enforce three novel constraints for the optimal adaptation: 1) negative data, 2) bottom-up pair-wise data constraints, and 3) adaptation dynamics. Substantializing the general adaptation problem as a subspace adaptation problem, this paper presents a closed-form solution as well as a practical iterative algorithm for subspace tracking. Extensive experiments have demonstrated that the proposed approach can largely alleviate adaptation drift and achieve better tracking results for a large variety of nonstationary scenes. PMID:19473941

  11. AVATAR -- Adaptive Visualization Aid for Touring And Recovery

    SciTech Connect

    L. O. Hall; K. W. Bowyer; N. Chawla; T. Moore, Jr.; W. P. Kegelmeyer

    2000-01-01

    This document provides a report on the initial development of software which uses a standard visualization tool to determine, label and display salient regions in large 3D physics simulation datasets. This software uses parallel pattern recognition behind the scenes to handle the huge volume of data. This software is called AVATAR (Adaptive Visualization Aid for Touring and Recovery). It integrates approaches to gathering labeled training data, learning from large training sets utilizing parallelism and the final display of salient data in unseen visualization data sets. The paper uses vorticity fields for a large-eddy simulation to illustrate the method.

  12. A collaborative visual analytics suite for protein folding research.

    PubMed

    Harvey, William; Park, In-Hee; Rübel, Oliver; Pascucci, Valerio; Bremer, Peer-Timo; Li, Chenglong; Wang, Yusu

    2014-09-01

    Molecular dynamics (MD) simulation is a crucial tool for understanding principles behind important biochemical processes such as protein folding and molecular interaction. With the rapidly increasing power of modern computers, large-scale MD simulation experiments can be performed regularly, generating huge amounts of MD data. An important question is how to analyze and interpret such massive and complex data. One of the (many) challenges involved in analyzing MD simulation data computationally is the high-dimensionality of such data. Given a massive collection of molecular conformations, researchers typically need to rely on their expertise and prior domain knowledge in order to retrieve certain conformations of interest. It is not easy to make and test hypotheses as the data set as a whole is somewhat "invisible" due to its high dimensionality. In other words, it is hard to directly access and examine individual conformations from a sea of molecular structures, and to further explore the entire data set. There is also no easy and convenient way to obtain a global view of the data or its various modalities of biochemical information. To this end, we present an interactive, collaborative visual analytics tool for exploring massive, high-dimensional molecular dynamics simulation data sets. The most important utility of our tool is to provide a platform where researchers can easily and effectively navigate through the otherwise "invisible" simulation data sets, exploring and examining molecular conformations both as a whole and at individual levels. The visualization is based on the concept of a topological landscape, which is a 2D terrain metaphor preserving certain topological and geometric properties of the high dimensional protein energy landscape. In addition to facilitating easy exploration of conformations, this 2D terrain metaphor also provides a platform where researchers can visualize and analyze various properties (such as contact density) overlayed on the

  13. Visual Analytics of integrated Data Systems for Space Weather Purposes

    NASA Astrophysics Data System (ADS)

    Rosa, Reinaldo; Veronese, Thalita; Giovani, Paulo

    Analysis of information from multiple data sources obtained through high resolution instrumental measurements has become a fundamental task in all scientific areas. The development of expert methods able to treat such multi-source data systems, with both large variability and measurement extension, is a key for studying complex scientific phenomena, especially those related to systemic analysis in space and environmental sciences. In this talk, we present a time series generalization introducing the concept of generalized numerical lattice, which represents a discrete sequence of temporal measures for a given variable. In this novel representation approach each generalized numerical lattice brings post-analytical data information. We define a generalized numerical lattice as a set of three parameters representing the following data properties: dimensionality, size and post-analytical measure (e.g., the autocorrelation, Hurst exponent, etc)[1]. From this representation generalization, any multi-source database can be reduced to a closed set of classified time series in spatiotemporal generalized dimensions. As a case study, we show a preliminary application in space science data, highlighting the possibility of a real time analysis expert system. In this particular application, we have selected and analyzed, using detrended fluctuation analysis (DFA), several decimetric solar bursts associated to X flare-classes. The association with geomagnetic activity is also reported. DFA method is performed in the framework of a radio burst automatic monitoring system. Our results may characterize the variability pattern evolution, computing the DFA scaling exponent, scanning the time series by a short windowing before the extreme event [2]. For the first time, the application of systematic fluctuation analysis for space weather purposes is presented. The prototype for visual analytics is implemented in a Compute Unified Device Architecture (CUDA) by using the K20 Nvidia

  14. DOE's SciDAC Visualization and Analytics Center for EnablingTechnologies -- Strategy for Petascale Visual Data Analysis Success

    SciTech Connect

    Bethel, E Wes; Johnson, Chris; Aragon, Cecilia; Rubel, Oliver; Weber, Gunther; Pascucci, Valerio; Childs, Hank; Bremer, Peer-Timo; Whitlock, Brad; Ahern, Sean; Meredith, Jeremey; Ostrouchov, George; Joy, Ken; Hamann, Bernd; Garth, Christoph; Cole, Martin; Hansen, Charles; Parker, Steven; Sanderson, Allen; Silva, Claudio; Tricoche, Xavier

    2007-10-01

    The focus of this article is on how one group of researchersthe DOE SciDAC Visualization and Analytics Center for EnablingTechnologies (VACET) is tackling the daunting task of enabling knowledgediscovery through visualization and analytics on some of the world slargest and most complex datasets and on some of the world's largestcomputational platforms. As a Center for Enabling Technology, VACET smission is the creation of usable, production-quality visualization andknowledge discovery software infrastructure that runs on large, parallelcomputer systems at DOE's Open Computing facilities and that providessolutions to challenging visual data exploration and knowledge discoveryneeds of modern science, particularly the DOE sciencecommunity.

  15. Visual Adaptation to Convexity in Macaque Area V4

    PubMed Central

    Müller, Kai-Markus; Wilke, Melanie; Leopold, David A.

    2009-01-01

    After-effects are perceptual illusions caused by visual adaptation to one or more stimulus attribute, such as orientation, motion, or shape, and are generally characterized by a repulsive shift in the perception of the adapted features in a corresponding test stimulus. Neurophysiological studies seeking to understand the basis of adaptation have observed firing rate reduction and changes in tuning of sensory neurons during periods of prolonged stimulation. In the domain of shape, recent psychophysical work has shown that adaptation to a convex pattern induces a subsequently seen rectangle to appear slightly concave. In the present study, we investigate the possible contribution of V4 neurons, which are thought to be involved in the coding of convexity, to such shape-specific adaptation. Visually responsive neurons were monitored during the brief presentation of simple shapes varying in their convexity level. Each test presentation was preceded by either a blank period or several seconds of adaptation to a convex or concave stimulus, presented in two different sizes. Adaptation consistently changed the tuning of neurons away from the convex or concave adaptor, shifting the response to the neutral rectangle in the direction of the opposite convexity. This repulsive shift was consistent with the known perceptual distortion associated with adaptation to such stimuli. Adaptation also caused a nonspecific decrease in firing, as well as the shape-selective suppression for the repeated presentation of the adaptor stimulus. The latter effects were observed whether or not the adapting and test stimuli matched closely in their size. Taken together, these results provide evidence for shape-specific adaptation of neurons in area V4, which may contribute to the perception of the convexity aftereffect. PMID:19345725

  16. Visual Space: Adaptation to Texture Density Reduces Perceived Object Size.

    PubMed

    Kingdom, Frederick A A

    2016-07-25

    A recent study shows that visual adaptation to dense textures, while causing an increase in the perceived sparseness of a subsequently viewed less-dense texture, paradoxically reduces the perceived size of an object, revealing a dissociation between the internal spatial representations of textures and objects.

  17. Visuomotor adaptation to a visual rotation is gravity dependent.

    PubMed

    Toma, Simone; Sciutti, Alessandra; Papaxanthis, Charalambos; Pozzo, Thierry

    2015-03-15

    Humans perform vertical and horizontal arm motions with different temporal patterns. The specific velocity profiles are chosen by the central nervous system by integrating the gravitational force field to minimize energy expenditure. However, what happens when a visuomotor rotation is applied, so that a motion performed in the horizontal plane is perceived as vertical? We investigated the dynamic of the adaptation of the spatial and temporal properties of a pointing motion during prolonged exposure to a 90° visuomotor rotation, where a horizontal movement was associated with a vertical visual feedback. We found that participants immediately adapted the spatial parameters of motion to the conflicting visual scene in order to keep their arm trajectory straight. In contrast, the initial symmetric velocity profiles specific for a horizontal motion were progressively modified during the conflict exposure, becoming more asymmetric and similar to those appropriate for a vertical motion. Importantly, this visual effect that increased with repetitions was not followed by a consistent aftereffect when the conflicting visual feedback was absent (catch and washout trials). In a control experiment we demonstrated that an intrinsic representation of the temporal structure of perceived vertical motions could provide the error signal allowing for this progressive adaptation of motion timing. These findings suggest that gravity strongly constrains motor learning and the reweighting process between visual and proprioceptive sensory inputs, leading to the selection of a motor plan that is suboptimal in terms of energy expenditure.

  18. Interocular transfer of adaptation in the primary visual cortex.

    PubMed

    Howarth, Christopher M; Vorobyov, Vasily; Sengpiel, Frank

    2009-08-01

    Prolonged viewing of an unchanging pattern causes adaptation, which can be demonstrated by visual aftereffects such as the tilt and waterfall illusions. In normal observers, these typically exhibit interocular transfer (IOT), being observed when the adapting and test stimuli are shown to different eyes. Convergence of inputs from both eyes upon binocular neurons only occurs in the primary visual cortex (V1), and adaptation is substantially a cortical phenomenon. However, little is known about a physiological substrate of IOT in V1 and how it relates to the binocularity of neurons and local ocular dominance (OD) column architecture. We employed optical imaging to obtain OD maps in cat V1 and recorded from single neurons at targeted penetration sites to quantify their adaptation by drifting gratings when adapter and test stimulus were presented either to the same or to the opposite eyes. In contrast to earlier reports, clear IOT of adaptation was observed for binocular as well as monocular neurons; at population level, its strength amounted to 55%. Moreover, the position of the cells with respect to OD column borders had no significant effect on the strength of IOT. IOT does not appear to strongly depend on conventional binocularity of neurons.

  19. Adaptive Processes in Thalamus and Cortex Revealed by Silencing of Primary Visual Cortex during Contrast Adaptation.

    PubMed

    King, Jillian L; Lowe, Matthew P; Stover, Kurt R; Wong, Aimee A; Crowder, Nathan A

    2016-05-23

    Visual adaptation illusions indicate that our perception is influenced not only by the current stimulus but also by what we have seen in the recent past. Adaptation to stimulus contrast (the relative luminance created by edges or contours in a scene) induces the perception of the stimulus fading away and increases the contrast detection threshold in psychophysical tests [1, 2]. Neural correlates of contrast adaptation have been described throughout the visual system including the retina [3], dorsal lateral geniculate nucleus (dLGN) [4, 5], primary visual cortex (V1) [6], and parietal cortex [7]. The apparent ubiquity of adaptation at all stages raises the question of how this process cascades across brain regions [8]. Focusing on V1, adaptation could be inherited from pre-cortical stages, arise from synaptic depression at the thalamo-cortical synapse [9], or develop locally, but what is the weighting of these contributions? Because contrast adaptation in mouse V1 is similar to classical animal models [10, 11], we took advantage of the optogenetic tools available in mice to disentangle the processes contributing to adaptation in V1. We disrupted cortical adaptation by optogenetically silencing V1 and found that adaptation measured in V1 now resembled that observed in dLGN. Thus, the majority of adaptation seen in V1 neurons arises through local activity-dependent processes, with smaller contributions from dLGN inheritance and synaptic depression at the thalamo-cortical synapse. Furthermore, modeling indicates that divisive scaling of the weakly adapted dLGN input can predict some of the emerging features of V1 adaptation.

  20. Epiviz: interactive visual analytics for functional genomics data.

    PubMed

    Chelaru, Florin; Smith, Llewellyn; Goldstein, Naomi; Bravo, Héctor Corrada

    2014-09-01

    Visualization is an integral aspect of genomics data analysis. Algorithmic-statistical analysis and interactive visualization are most effective when used iteratively. Epiviz (http://epiviz.cbcb.umd.edu/), a web-based genome browser, and the Epivizr Bioconductor package allow interactive, extensible and reproducible visualization within a state-of-the-art data-analysis platform.

  1. Adaptive tuning functions arise from visual observation of past movement

    PubMed Central

    Howard, Ian S.; Franklin, David W.

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  2. Adaptive tuning functions arise from visual observation of past movement.

    PubMed

    Howard, Ian S; Franklin, David W

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  3. Visualizing Geophysical Flow Problems with Adaptive Mesh Refinement

    NASA Astrophysics Data System (ADS)

    Sevre, E. O.; Yuen, D. A.; George, D. L.; Lee, S.

    2011-12-01

    Adaptive Mesh Refinement (AMR) is a technique used in software to decompose a computational domain based on the level of refinement necessary for spatial and temporal calculations. Comparing AMR runs to uniform grids allows for an unbounded gain in computational time. In this paper we will look at techniques for visualizing tsunami simulations that were run with AMR using the GeoClaw [Berger2011-1, Berger2011-2] software. Due to the computational efficiency of AMR we have decided to look into techniques for visualization of AMR data. By having good visualization tools for geoscientists more time can be spent interpreting results and analyzing data. Good visualization tools can be adapted easily to work with a variety of output formats, and the goal of this work is to provide a foundation for geoscientists to work with. In the past year GeoClaw has been used to model the 2011 Tohoku tsunami originating off the coast of Sendai Japan and delivering catastrophic damage to the Fukushima power plant. The aftermath of this single geologic event is still making headlines 4 months after the fact [Fackler2011]. GeoClaw utilizes the shallow water equations to model a variety of flows that range from tsunami to floods to landslides and debris flows [George2011]. With the advanced computations provided by AMR it is important for researchers to visualize and understand ways that are meaningful to both scientists and civilians affected by the potential outcomes of the computation. Special visualization techniques can be used to visualize and look at data generated with AMR. By incorporating these techniques into their software geoscientists will be able to harness powerful computational tools, such as GeoClaw, while also maintaining an informative view of their data.

  4. Atypical visual and somatosensory adaptation in schizophrenia-spectrum disorders

    PubMed Central

    Andrade, G N; Butler, J S; Peters, G A; Molholm, S; Foxe, J J

    2016-01-01

    Neurophysiological investigations in patients with schizophrenia consistently show early sensory processing deficits in the visual system. Importantly, comparable sensory deficits have also been established in healthy first-degree biological relatives of patients with schizophrenia and in first-episode drug-naive patients. The clear implication is that these measures are endophenotypic, related to the underlying genetic liability for schizophrenia. However, there is significant overlap between patient response distributions and those of healthy individuals without affected first-degree relatives. Here we sought to develop more sensitive measures of sensory dysfunction in this population, with an eye to establishing endophenotypic markers with better predictive capabilities. We used a sensory adaptation paradigm in which electrophysiological responses to basic visual and somatosensory stimuli presented at different rates (ranging from 250 to 2550 ms interstimulus intervals, in blocked presentations) were compared. Our main hypothesis was that adaptation would be substantially diminished in schizophrenia, and that this would be especially prevalent in the visual system. High-density event-related potential recordings showed amplitude reductions in sensory adaptation in patients with schizophrenia (N=15 Experiment 1, N=12 Experiment 2) compared with age-matched healthy controls (N=15 Experiment 1, N=12 Experiment 2), and this was seen for both sensory modalities. At the individual participant level, reduced adaptation was more robust for visual compared with somatosensory stimulation. These results point to significant impairments in short-term sensory plasticity across sensory modalities in schizophrenia. These simple-to-execute measures may prove valuable as candidate endophenotypes and will bear follow-up in future work. PMID:27163205

  5. Visual-adaptation-mechanism based underwater object extraction

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Wang, Huibin; Xu, Lizhong; Shen, Jie

    2014-03-01

    Due to the major obstacles originating from the strong light absorption and scattering in a dynamic underwater environment, underwater optical information acquisition and processing suffer from effects such as limited range, non-uniform lighting, low contrast, and diminished colors, causing it to become the bottleneck for marine scientific research and projects. After studying and generalizing the underwater biological visual mechanism, we explore its advantages in light adaption which helps animals to precisely sense the underwater scene and recognize their prey or enemies. Then, aiming to transform the significant advantage of the visual adaptation mechanism into underwater computer vision tasks, a novel knowledge-based information weighting fusion model is established for underwater object extraction. With this bionic model, the dynamical adaptability is given to the underwater object extraction task, making them more robust to the variability of the optical properties in different environments. The capability of the proposed method to adapt to the underwater optical environments is shown, and its outperformance for the object extraction is demonstrated by comparison experiments.

  6. Adaptation to stimulus contrast and correlations during natural visual stimulation

    PubMed Central

    Lesica, Nicholas A.; Jin, Jianzhong; Weng, Chong; Yeh, Chun-I; Butts, Daniel A.; Stanley, Garrett B.; Alonso, Jose-Manuel

    2008-01-01

    Summary In this study, we characterize the adaptation of neurons in the cat lateral geniculate nucleus to changes in stimulus contrast and correlations. By comparing responses to high and low contrast natural scene movie and white noise stimuli, we show that an increase in contrast or correlations results in receptive fields with faster temporal dynamics and stronger antagonistic surrounds, as well as decreases in gain and selectivity. We also observe contrast- and correlation-induced changes in the reliability and sparseness of neural responses. We find that reliability is determined primarily by processing in the receptive field (the effective contrast of the stimulus), while sparseness is determined by the interactions between several functional properties. These results reveal a number of novel adaptive phenomena and suggest that adaptation to stimulus contrast and correlations may play an important role in visual coding in a dynamic natural environment. PMID:17678859

  7. Interaction Junk: User Interaction-Based Evaluation of Visual Analytic Systems

    SciTech Connect

    Endert, Alexander; North, Chris

    2012-10-14

    With the growing need for visualization to aid users in understanding large, complex datasets, the ability for users to interact and explore these datasets is critical. As visual analytic systems have advanced to leverage powerful computational models and data analytics capabilities, the modes by which users engage and interact with the information are limited. Often, users are taxed with directly manipulating parameters of these models through traditional GUIs (e.g., using sliders to directly manipulate the value of a parameter). However, the purpose of user interaction in visual analytic systems is to enable visual data exploration – where users can focus on their task, as opposed to the tool or system. As a result, users can engage freely in data exploration and decision-making, for the purpose of gaining insight. In this position paper, we discuss how evaluating visual analytic systems can be approached through user interaction analysis, where the goal is to minimize the cognitive translation between the visual metaphor and the mode of interaction (i.e., reducing the “Interactionjunk”). We motivate this concept through a discussion of traditional GUIs used in visual analytics for direct manipulation of model parameters, and the importance of designing interactions the support visual data exploration.

  8. Adaptive information interactive mechanism for multi-UAV visual navigation

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    Multi-unmanned aerial vehicle (UAV) cooperative communication for visual navigation has recently generated significant concern. It has large amounts of visual information to be transmitted and processed among UAVs with realtime requirements. And the UAV clusters have self-organized, time-varying and high dynamic characteristics. Considering the above conditions, we propose an adaptive information interactive mechanism (AIIM) for multi-UAV visual navigation. In the mechanism, the function modules for UAV inter-communication interface are designed, the mobility-based link lifetime is established and the information interactive protocol is presented. Thus we combine the mobility of UAVs with the corresponding communication requirements to make effective information interaction for UAVs. Task-oriented distributed control is adopted to improve the collaboration flexibility in the multi-UAV visual navigation system. In order to timely obtain the necessary visual information, each UAV can cooperate with other relevant UAVs which meet some certain terms such as situation, task or environmental conditions. Simulation results are presented to show the validity of the proposed mechanism in terms of end-to-end delay and links stability.

  9. Adaptation to visual or auditory time intervals modulates the perception of visual apparent motion

    PubMed Central

    Zhang, Huihui; Chen, Lihan; Zhou, Xiaolin

    2012-01-01

    It is debated whether sub-second timing is subserved by a centralized mechanism or by the intrinsic properties of task-related neural activity in specific modalities (Ivry and Schlerf, 2008). By using a temporal adaptation task, we investigated whether adapting to different time intervals conveyed through stimuli in different modalities (i.e., frames of a visual Ternus display, visual blinking discs, or auditory beeps) would affect the subsequent implicit perception of visual timing, i.e., inter-stimulus interval (ISI) between two frames in a Ternus display. The Ternus display can induce two percepts of apparent motion (AM), depending on the ISI between the two frames: “element motion” for short ISIs, in which the endmost disc is seen as moving back and forth while the middle disc at the overlapping or central position remains stationary; “group motion” for longer ISIs, in which both discs appear to move in a manner of lateral displacement as a whole. In Experiment 1, participants adapted to either the typical “element motion” (ISI = 50 ms) or the typical “group motion” (ISI = 200 ms). In Experiments 2 and 3, participants adapted to a time interval of 50 or 200 ms through observing a series of two paired blinking discs at the center of the screen (Experiment 2) or hearing a sequence of two paired beeps (with pitch 1000 Hz). In Experiment 4, participants adapted to sequences of paired beeps with either low pitches (500 Hz) or high pitches (5000 Hz). After adaptation in each trial, participants were presented with a Ternus probe in which the ISI between the two frames was equal to the transitional threshold of the two types of motions, as determined by a pretest. Results showed that adapting to the short time interval in all the situations led to more reports of “group motion” in the subsequent Ternus probes; adapting to the long time interval, however, caused no aftereffect for visual adaptation but significantly more reports of group motion for

  10. Examining the Use of a Visual Analytics System for Sensemaking Tasks: Case Studies with Domain Experts.

    PubMed

    Kang, Youn-Ah; Stasko, J

    2012-12-01

    While the formal evaluation of systems in visual analytics is still relatively uncommon, particularly rare are case studies of prolonged system use by domain analysts working with their own data. Conducting case studies can be challenging, but it can be a particularly effective way to examine whether visual analytics systems are truly helping expert users to accomplish their goals. We studied the use of a visual analytics system for sensemaking tasks on documents by six analysts from a variety of domains. We describe their application of the system along with the benefits, issues, and problems that we uncovered. Findings from the studies identify features that visual analytics systems should emphasize as well as missing capabilities that should be addressed. These findings inform design implications for future systems.

  11. A Visual Analytics Approach to Structured Data Analysis to Enhance Nonproliferation and Arms Control Verification Activities

    SciTech Connect

    Gillen, David S.

    2014-08-07

    Analysis activities for Nonproliferation and Arms Control verification require the use of many types of data. Tabular structured data, such as Excel spreadsheets and relational databases, have traditionally been used for data mining activities, where specific queries are issued against data to look for matching results. The application of visual analytics tools to structured data enables further exploration of datasets to promote discovery of previously unknown results. This paper discusses the application of a specific visual analytics tool to datasets related to the field of Arms Control and Nonproliferation to promote the use of visual analytics more broadly in this domain. Visual analytics focuses on analytical reasoning facilitated by interactive visual interfaces (Wong and Thomas 2004). It promotes exploratory analysis of data, and complements data mining technologies where known patterns can be mined for. Also with a human in the loop, they can bring in domain knowledge and subject matter expertise. Visual analytics has not widely been applied to this domain. In this paper, we will focus on one type of data: structured data, and show the results of applying a specific visual analytics tool to answer questions in the Arms Control and Nonproliferation domain. We chose to use the T.Rex tool, a visual analytics tool developed at PNNL, which uses a variety of visual exploration patterns to discover relationships in structured datasets, including a facet view, graph view, matrix view, and timeline view. The facet view enables discovery of relationships between categorical information, such as countries and locations. The graph tool visualizes node-link relationship patterns, such as the flow of materials being shipped between parties. The matrix visualization shows highly correlated categories of information. The timeline view shows temporal patterns in data. In this paper, we will use T.Rex with two different datasets to demonstrate how interactive exploration of

  12. Coherent Image Layout using an Adaptive Visual Vocabulary

    SciTech Connect

    Dillard, Scott E.; Henry, Michael J.; Bohn, Shawn J.; Gosink, Luke J.

    2013-03-06

    When querying a huge image database containing millions of images, the result of the query may still contain many thousands of images that need to be presented to the user. We consider the problem of arranging such a large set of images into a visually coherent layout, one that places similar images next to each other. Image similarity is determined using a bag-of-features model, and the layout is constructed from a hierarchical clustering of the image set by mapping an in-order traversal of the hierarchy tree into a space-filling curve. This layout method provides strong locality guarantees so we are able to quantitatively evaluate performance using standard image retrieval benchmarks. Performance of the bag-of-features method is best when the vocabulary is learned on the image set being clustered. Because learning a large, discriminative vocabulary is a computationally demanding task, we present a novel method for efficiently adapting a generic visual vocabulary to a particular dataset. We evaluate our clustering and vocabulary adaptation methods on a variety of image datasets and show that adapting a generic vocabulary to a particular set of images improves performance on both hierarchical clustering and image retrieval tasks.

  13. Improved visual background extractor using an adaptive distance threshold

    NASA Astrophysics Data System (ADS)

    Han, Guang; Wang, Jinkuan; Cai, Xi

    2014-11-01

    Camouflage is a challenging issue in moving object detection. Even the recent and advanced background subtraction technique, visual background extractor (ViBe), cannot effectively deal with it. To better handle camouflage according to the perception characteristics of the human visual system (HVS) in terms of minimum change of intensity under a certain background illumination, we propose an improved ViBe method using an adaptive distance threshold, named IViBe for short. Different from the original ViBe using a fixed distance threshold for background matching, our approach adaptively sets a distance threshold for each background sample based on its intensity. Through analyzing the performance of the HVS in discriminating intensity changes, we determine a reasonable ratio between the intensity of a background sample and its corresponding distance threshold. We also analyze the impacts of our adaptive threshold together with an update mechanism on detection results. Experimental results demonstrate that our method outperforms ViBe even when the foreground and background share similar intensities. Furthermore, in a scenario where foreground objects are motionless for several frames, our IViBe not only reduces the initial false negatives, but also suppresses the diffusion of misclassification caused by those false negatives serving as erroneous background seeds, and hence shows an improved performance compared to ViBe.

  14. VisualDecisionLinc: a visual analytics approach for comparative effectiveness-based clinical decision support in psychiatry.

    PubMed

    Mane, Ketan K; Bizon, Chris; Schmitt, Charles; Owen, Phillips; Burchett, Bruce; Pietrobon, Ricardo; Gersing, Kenneth

    2012-02-01

    Comparative Effectiveness Research (CER) is designed to provide research evidence on the effectiveness and risks of different therapeutic options on the basis of data compiled from subpopulations of patients with similar medical conditions. Electronic Health Record (EHR) system contain large volumes of patient data that could be used for CER, but the data contained in EHR system are typically accessible only in formats that are not conducive to rapid synthesis and interpretation of therapeutic outcomes. In the time-pressured clinical setting, clinicians faced with large amounts of patient data in formats that are not readily interpretable often feel 'information overload'. Decision support tools that enable rapid access at the point of care to aggregate data on the most effective therapeutic outcomes derived from CER would greatly aid the clinical decision-making process and individualize patient care. In this manuscript, we highlight the role that visual analytics can play in CER-based clinical decision support. We developed a 'VisualDecisionLinc' (VDL) tool prototype that uses visual analytics to provide summarized CER-derived data views to facilitate rapid interpretation of large amounts of data. We highlight the flexibility that visual analytics offers to gain an overview of therapeutic options and outcomes and if needed, to instantly customize the evidence to the needs of the patient or clinician. The VDL tool uses visual analytics to help the clinician evaluate and understand the effectiveness and risk of different therapeutic options for different subpopulations of patients.

  15. Walking the Path—A New Journey to Explore and Discover through Visual Analytics

    SciTech Connect

    Wong, Pak C.; Rose, Stuart J.; Chin, George; Frincke, Deb; May, Richard A.; Posse, Christian; Sanfilippo, Antonio P.; Thomas, James J.

    2006-12-01

    Visual representations are essential aids to human cognitive tasks and are valued to the extent that they provide stable and external reference points upon which dynamic activities and thought processes may be calibrated and upon which models and theories can be tested and confirmed. The active use and manipulation of visual representations makes many complex and intensive cognitive tasks feasible. As described in the recently published ''Illuminating the Path'', visual analytics is ''the science of analytical reasoning facilitated by interactive visual interfaces''. We describe research and development at PNNL focused on improving the value that interactive visual representations provide to persons engaged in complex cognitive tasks. We describe work at PNNL that carries forward research from multiple disciplines with a goal to improve the capability of visual representations and present examples whose aim is to improve the extraction, and reasoning about information, knowledge, and data.

  16. Learning Analytics: A Case Study of the Process of Design of Visualizations

    ERIC Educational Resources Information Center

    Olmos, Martin; Corrin, Linda

    2012-01-01

    The ability to visualize student engagement and experience data provides valuable opportunities for learning support and curriculum design. With the rise of the use of learning analytics to provide "actionable intelligence" on students' learning, the challenge is to create visualizations of the data, which are clear and useful to the intended…

  17. Measurements of contrast sensitivity by an adaptive optics visual simulator

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tatsuo; Ucikawa, Keiji

    2015-08-01

    We developed an adaptive optics visual simulator (AOVS) to study the relationship between the contrast sensitivity and higher-order wavefront aberrations of human eyes. A desired synthetic aberration was virtually generated on a subject eye by the AOVS, and red laser light was used to measure the aberrations. The contrast sensitivity was measured in a psychophysical experiment using visual stimulus patterns provided by a large-contrast-range imaging system, which included two liquid crystal displays illuminated by red light emitting diodes from the backside. The diameter of the pupil was set to 4 mm by an artificial aperture, and the retinal illuminance of the stimulus image was controlled to 10 Td. Experiments conducted with four normal subjects revealed that their contrast sensitivity to a high-spatial-frequency vertical sinusoidal grating pattern was lower in the presence of a horizontal coma aberration than in the presence of a vertical coma or no aberrations ( p < 0.02, Nagai method).

  18. CiteRivers: Visual Analytics of Citation Patterns.

    PubMed

    Heimerl, Florian; Han, Qi; Koch, Steffen; Ertl, Thomas

    2016-01-01

    The exploration and analysis of scientific literature collections is an important task for effective knowledge management. Past interest in such document sets has spurred the development of numerous visualization approaches for their interactive analysis. They either focus on the textual content of publications, or on document metadata including authors and citations. Previously presented approaches for citation analysis aim primarily at the visualization of the structure of citation networks and their exploration. We extend the state-of-the-art by presenting an approach for the interactive visual analysis of the contents of scientific documents, and combine it with a new and flexible technique to analyze their citations. This technique facilitates user-steered aggregation of citations which are linked to the content of the citing publications using a highly interactive visualization approach. Through enriching the approach with additional interactive views of other important aspects of the data, we support the exploration of the dataset over time and enable users to analyze citation patterns, spot trends, and track long-term developments. We demonstrate the strengths of our approach through a use case and discuss it based on expert user feedback.

  19. Selective visual attention based clutter metric with human visual system adaptability.

    PubMed

    Zheng, Bo; Wang, Xiao-Dong; Huang, Jing-Tao; Wang, Jian; Jiang, Yang

    2016-09-20

    Most existing clutter metrics are proposed based on fixed structural features and experienced weight measures. In this paper, we identify the clutter as selective visual attention effects and propose a type of clutter metric. First, adaptive structural features are extracted from the blocks with an edge-structure similarity to the target. Next, the confusing blocks are selected by the similarity threshold based on the attention guidance map. The clutter is estimated by quantifying the effects of confusing blocks on target acquisition performance. The comparative field experiments, with a Search_2 dataset, show that the proposed metric is consistent with the adaptability of the human visual system (HVS) and outperforms other metrics. PMID:27661600

  20. A saliency based motion detection model of visual system considering visual adaptation properties.

    PubMed

    Kodama, Mitsuhiro; Kohama, Takeshi; Yoshida, Hisashi

    2015-01-01

    The purpose of this study is to construct a mathematical model which predicts saliency regions in high-speed egocentric-motion movies, filmed by an embedded camera in a driving vehicle, by reproducing the characteristics of the area MT and MST neurons' receptive fields with consideration of visual adaptation properties. The area MT neurons integrate from the area V1 activation and respond well to regions where higher motion contrasts exist. While the area MST neurons detect global motions such as expansion, contraction, rotation, and so on. We modeled the area MT neurons' receptive fields as a center-surround spatial summation of counter sided motion vectors of visual scenery. The area MST neurons in our model integrate the responses of the MT neurons by convolving with spacial weight functions of which central portions are biased to preferred direction. Visual adaptations were taken as the primary delay filters for each visual feature channel to deplete the saliency of stationary objects and regions during particular frames. The simulation results for the movies which were taken in a running vehicle indicate that the proposed model detects more salient objects around the vanishing point than the conventional saliency based model. To evaluate the performance of proposed model, we defined the moving-NSS (normalized scan-path salience) scores as the averaged NSS scores in each moving time window. The moving-NSS scores for motion images of our model were higher than those of the conventional model. PMID:26737820

  1. EmailTime: visual analytics and statistics for temporal email

    NASA Astrophysics Data System (ADS)

    Erfani Joorabchi, Minoo; Yim, Ji-Dong; Shaw, Christopher D.

    2011-01-01

    Although the discovery and analysis of communication patterns in large and complex email datasets are difficult tasks, they can be a valuable source of information. We present EmailTime, a visual analysis tool of email correspondence patterns over the course of time that interactively portrays personal and interpersonal networks using the correspondence in the email dataset. Our approach is to put time as a primary variable of interest, and plot emails along a time line. EmailTime helps email dataset explorers interpret archived messages by providing zooming, panning, filtering and highlighting etc. To support analysis, it also measures and visualizes histograms, graph centrality and frequency on the communication graph that can be induced from the email collection. This paper describes EmailTime's capabilities, along with a large case study with Enron email dataset to explore the behaviors of email users within different organizational positions from January 2000 to December 2001. We defined email behavior as the email activity level of people regarding a series of measured metrics e.g. sent and received emails, numbers of email addresses, etc. These metrics were calculated through EmailTime. Results showed specific patterns in the use email within different organizational positions. We suggest that integrating both statistics and visualizations in order to display information about the email datasets may simplify its evaluation.

  2. The Adaptive Analysis of Visual Cognition using Genetic Algorithms

    PubMed Central

    Cook, Robert G.; Qadri, Muhammad A. J.

    2014-01-01

    Two experiments used a novel, open-ended, and adaptive test procedure to examine visual cognition in animals. Using a genetic algorithm, a pigeon was tested repeatedly from a variety of different initial conditions for its solution to an intermediate brightness search task. On each trial, the animal had to accurately locate and peck a target element of intermediate brightness from among a variable number of surrounding darker and lighter distractor elements. Displays were generated from six parametric variables, or genes (distractor number, element size, shape, spacing, target brightness, distractor brightness). Display composition changed over time, or evolved, as a function of the bird’s differential accuracy within the population of values for each gene. Testing three randomized initial conditions and one set of controlled initial conditions, element size and number of distractors were identified as the most important factors controlling search accuracy, with distractor brightness, element shape, and spacing making secondary contributions. The resulting changes in this multidimensional stimulus space suggested the existence of a set of conditions that the bird repeatedly converged upon regardless of initial conditions. This psychological “attractor” represents the cumulative action of the cognitive operations used by the pigeon in solving and performing this search task. The results are discussed regarding their implications for visual cognition in pigeons and the usefulness of adaptive, subject-driven experimentation for investigating human and animal cognition more generally. PMID:24000905

  3. Visual model of human blur perception for scene adaptive capturing

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Su; Chung, DaeSu; Park, Byung-Kwan; Kim, Jung-Bae; Lee, Seong-Deok

    2009-01-01

    Despite fast spreading of digital cameras, many people cannot take pictures of high quality, they want, due to lack of photography. To help users under the unfavorable capturing environments, e.g. 'Night', 'Backlighting', 'Indoor', or 'Portrait', the automatic mode of cameras provides parameter sets by manufactures. Unfortunately, this automatic functionality does not give pleasing image quality in general. Especially, length of exposure (shutter speed) is critical factor in taking high quality pictures in the night. One of key factors causing this bad quality in the night is the image blur, which mainly comes from hand-shaking in long capturing. In this study, to circumvent this problem and to enhance image quality of automatic cameras, we propose an intelligent camera processing core having BASE (Scene Adaptive Blur Estimation) and VisBLE (Visual Blur Limitation Estimation). SABE analyzes the high frequency component in the DCT (Discrete Cosine Transform) domain. VisBLE determines acceptable blur level on the basis of human visual tolerance and Gaussian model. This visual tolerance model is developed on the basis of human perception physiological mechanism. In the experiments proposed method outperforms existing imaging systems by general users and photographers, as well.

  4. Universal and adapted vocabularies for generic visual categorization.

    PubMed

    Perronnin, Florent

    2008-07-01

    Generic Visual Categorization (GVC) is the pattern classification problem which consists in assigning labels to an image based on its semantic content. This is a challenging task as one has to deal with inherent object/scene variations as well as changes in viewpoint, lighting and occlusion. Several state-of-the-art GVC systems use a vocabulary of visual terms to characterize images with a histogram of visual word counts. We propose a novel practical approach to GVC based on a universal vocabulary, which describes the content of all the considered classes of images, and class vocabularies obtained through the adaptation of the universal vocabulary using class-specific data. The main novelty is that an image is characterized by a set of histograms - one per class - where each histogram describes whether the image content is best modeled by the universal vocabulary or the corresponding class vocabulary. This framework is applied to two types of local image features: low-level descriptors such as the popular SIFT and high-level histograms of word co-occurrences in a spatial neighborhood. It is shown experimentally on two challenging datasets (an in-house database of 19 categories and the PASCAL VOC 2006 dataset) that the proposed approach exhibits state-of-the-art performance at a modest computational cost.

  5. Adaptive Behavior of Primary School Students with Visual Impairments: The Impact of Educational Settings

    ERIC Educational Resources Information Center

    Metsiou, Katerina; Papadopoulos, Konstantinos; Agaliotis, Ioannis

    2011-01-01

    This study explored the adaptive behavior of primary school students with visual impairments, as well as the impact of educational setting on their adaptive behavior. Instrumentation included an informal questionnaire and the Vineland Adaptive Behavior Scales. Participants were 36 primary school students with visual impairments. The educational…

  6. Visual analytics of anomaly detection in large data streams

    NASA Astrophysics Data System (ADS)

    Hao, Ming C.; Dayal, Umeshwar; Keim, Daniel A.; Sharma, Ratnesh K.; Mehta, Abhay

    2009-01-01

    Most data streams usually are multi-dimensional, high-speed, and contain massive volumes of continuous information. They are seen in daily applications, such as telephone calls, retail sales, data center performance, and oil production operations. Many analysts want insight into the behavior of this data. They want to catch the exceptions in flight to reveal the causes of the anomalies and to take immediate action. To guide the user in finding the anomalies in the large data stream quickly, we derive a new automated neighborhood threshold marking technique, called AnomalyMarker. This technique is built on cell-based data streams and user-defined thresholds. We extend the scope of the data points around the threshold to include the surrounding areas. The idea is to define a focus area (marked area) which enables users to (1) visually group the interesting data points related to the anomalies (i.e., problems that occur persistently or occasionally) for observing their behavior; (2) discover the factors related to the anomaly by visualizing the correlations between the problem attribute with the attributes of the nearby data items from the entire multi-dimensional data stream. Mining results are quickly presented in graphical representations (i.e., tooltip) for the user to zoom into the problem regions. Different algorithms are introduced which try to optimize the size and extent of the anomaly markers. We have successfully applied this technique to detect data stream anomalies in large real-world enterprise server performance and data center energy management.

  7. Evaluation methodology for comparing memory and communication of analytic processes in visual analytics

    SciTech Connect

    Ragan, Eric D; Goodall, John R

    2014-01-01

    Provenance tools can help capture and represent the history of analytic processes. In addition to supporting analytic performance, provenance tools can be used to support memory of the process and communication of the steps to others. Objective evaluation methods are needed to evaluate how well provenance tools support analyst s memory and communication of analytic processes. In this paper, we present several methods for the evaluation of process memory, and we discuss the advantages and limitations of each. We discuss methods for determining a baseline process for comparison, and we describe various methods that can be used to elicit process recall, step ordering, and time estimations. Additionally, we discuss methods for conducting quantitative and qualitative analyses of process memory. By organizing possible memory evaluation methods and providing a meta-analysis of the potential benefits and drawbacks of different approaches, this paper can inform study design and encourage objective evaluation of process memory and communication.

  8. Transformation of an uncertain video search pipeline to a sketch-based visual analytics loop.

    PubMed

    Legg, Philip A; Chung, David H S; Parry, Matthew L; Bown, Rhodri; Jones, Mark W; Griffiths, Iwan W; Chen, Min

    2013-12-01

    Traditional sketch-based image or video search systems rely on machine learning concepts as their core technology. However, in many applications, machine learning alone is impractical since videos may not be semantically annotated sufficiently, there may be a lack of suitable training data, and the search requirements of the user may frequently change for different tasks. In this work, we develop a visual analytics systems that overcomes the shortcomings of the traditional approach. We make use of a sketch-based interface to enable users to specify search requirement in a flexible manner without depending on semantic annotation. We employ active machine learning to train different analytical models for different types of search requirements. We use visualization to facilitate knowledge discovery at the different stages of visual analytics. This includes visualizing the parameter space of the trained model, visualizing the search space to support interactive browsing, visualizing candidature search results to support rapid interaction for active learning while minimizing watching videos, and visualizing aggregated information of the search results. We demonstrate the system for searching spatiotemporal attributes from sports video to identify key instances of the team and player performance.

  9. Learning to read aligns visual analytical skills with grapheme-phoneme mapping: evidence from illiterates

    PubMed Central

    Lachmann, Thomas; Khera, Gunjan; Srinivasan, Narayanan; van Leeuwen, Cees

    2012-01-01

    Learning to read puts evolutionary established speech and visual object recognition functions to novel use. As we previously showed, this leads to particular rearrangements and differentiations in these functions, for instance the habitual preference for holistic perceptual organization in visual object recognition and its suppression in perceiving letters. We performed the experiment in which the differentiation between holistic non-letter processing and analytic letter processing in literates was originally shown (van Leeuwen and Lachmann, 2004) with illiterate adults. The original differentiation is absent in illiterates; they uniformly showed analytic perception for both letters and non-letters. The result implies that analytic visual perception is not a secondary development resulting from learning to read but, rather, a primary mode of perceptual organization on a par with holistic perception. PMID:22701421

  10. Adaptive, multiresolution visualization of large data sets using parallel octrees.

    SciTech Connect

    Freitag, L. A.; Loy, R. M.

    1999-06-10

    The interactive visualization and exploration of large scientific data sets is a challenging and difficult task; their size often far exceeds the performance and memory capacity of even the most powerful graphics work-stations. To address this problem, we have created a technique that combines hierarchical data reduction methods with parallel computing to allow interactive exploration of large data sets while retaining full-resolution capability. The hierarchical representation is built in parallel by strategically inserting field data into an octree data structure. We provide functionality that allows the user to interactively adapt the resolution of the reduced data sets so that resolution is increased in regions of interest without sacrificing local graphics performance. We describe the creation of the reduced data sets using a parallel octree, the software architecture of the system, and the performance of this system on the data from a Rayleigh-Taylor instability simulation.

  11. A reference web architecture and patterns for real-time visual analytics on large streaming data

    NASA Astrophysics Data System (ADS)

    Kandogan, Eser; Soroker, Danny; Rohall, Steven; Bak, Peter; van Ham, Frank; Lu, Jie; Ship, Harold-Jeffrey; Wang, Chun-Fu; Lai, Jennifer

    2013-12-01

    Monitoring and analysis of streaming data, such as social media, sensors, and news feeds, has become increasingly important for business and government. The volume and velocity of incoming data are key challenges. To effectively support monitoring and analysis, statistical and visual analytics techniques need to be seamlessly integrated; analytic techniques for a variety of data types (e.g., text, numerical) and scope (e.g., incremental, rolling-window, global) must be properly accommodated; interaction, collaboration, and coordination among several visualizations must be supported in an efficient manner; and the system should support the use of different analytics techniques in a pluggable manner. Especially in web-based environments, these requirements pose restrictions on the basic visual analytics architecture for streaming data. In this paper we report on our experience of building a reference web architecture for real-time visual analytics of streaming data, identify and discuss architectural patterns that address these challenges, and report on applying the reference architecture for real-time Twitter monitoring and analysis.

  12. Visual enhancement of unmixed multispectral imagery using adaptive smoothing

    USGS Publications Warehouse

    Lemeshewsky, G.P.; Rahman, Z.-U.; Schowengerdt, R.A.; Reichenbach, S.E.

    2004-01-01

    Adaptive smoothing (AS) has been previously proposed as a method to smooth uniform regions of an image, retain contrast edges, and enhance edge boundaries. The method is an implementation of the anisotropic diffusion process which results in a gray scale image. This paper discusses modifications to the AS method for application to multi-band data which results in a color segmented image. The process was used to visually enhance the three most distinct abundance fraction images produced by the Lagrange constraint neural network learning-based unmixing of Landsat 7 Enhanced Thematic Mapper Plus multispectral sensor data. A mutual information-based method was applied to select the three most distinct fraction images for subsequent visualization as a red, green, and blue composite. A reported image restoration technique (partial restoration) was applied to the multispectral data to reduce unmixing error, although evaluation of the performance of this technique was beyond the scope of this paper. The modified smoothing process resulted in a color segmented image with homogeneous regions separated by sharpened, coregistered multiband edges. There was improved class separation with the segmented image, which has importance to subsequent operations involving data classification.

  13. MatrixFlow: Temporal Network Visual Analytics to Track Symptom Evolution during Disease Progression

    PubMed Central

    Perer, Adam; Sun, Jimeng

    2012-01-01

    Objective: To develop a visual analytic system to help medical professionals improve disease diagnosis by providing insights for understanding disease progression. Methods: We develop MatrixFlow, a visual analytic system that takes clinical event sequences of patients as input, constructs time-evolving networks and visualizes them as a temporal flow of matrices. MatrixFlow provides several interactive features for analysis: 1) one can sort the events based on the similarity in order to accentuate underlying cluster patterns among those events; 2) one can compare co-occurrence events over time and across cohorts through additional line graph visualization. Results: MatrixFlow is applied to visualize heart failure (HF) symptom events extracted from a large cohort of HF cases and controls (n=50,625), which allows medical experts to reach insights involving temporal patterns and clusters of interest, and compare cohorts in novel ways that may lead to improved disease diagnoses. Conclusions: MatrixFlow is an interactive visual analytic system that allows users to quickly discover patterns in clinical event sequences. By unearthing the patterns hidden within and displaying them to medical experts, users become empowered to make decisions influenced by historical patterns. PMID:23304345

  14. PAVA: Physiological and Anatomical Visual Analytics for Mapping of Tissue-Specific Concentration and Time-Course Data

    EPA Science Inventory

    We describe the development and implementation of a Physiological and Anatomical Visual Analytics tool (PAVA), a web browser-based application, used to visualize experimental/simulated chemical time-course data (dosimetry), epidemiological data and Physiologically-Annotated Data ...

  15. Oculomotor Adaptation Elicited By Intra-Saccadic Visual Stimulation: Time-Course of Efficient Visual Target Perturbation

    PubMed Central

    Panouillères, Muriel T. N.; Gaveau, Valerie; Debatisse, Jeremy; Jacquin, Patricia; LeBlond, Marie; Pélisson, Denis

    2016-01-01

    Perception of our visual environment strongly depends on saccadic eye movements, which in turn are calibrated by saccadic adaptation mechanisms elicited by systematic movement errors. Current models of saccadic adaptation assume that visual error signals are acquired only after saccade completion, because the high speed of saccade execution disturbs visual processing (saccadic “suppression” and “mislocalization”). Complementing a previous study from our group, here we report that visual information presented during saccades can drive adaptation mechanisms and we further determine the critical time window of such error processing. In 15 healthy volunteers, shortening adaptation of reactive saccades toward a ±8° visual target was induced by flashing the target for 2 ms less eccentrically than its initial location either near saccade peak velocity (“PV” condition) or peak deceleration (“PD”) or saccade termination (“END”). Results showed that, as compared to the “CONTROL” condition (target flashed at its initial location upon saccade termination), saccade amplitude decreased all throughout the “PD” and “END” conditions, reaching significant levels in the second adaptation and post-adaptation blocks. The results of nine other subjects tested in a saccade lengthening adaptation paradigm with the target flashing near peak deceleration (“PD” and “CONTROL” conditions) revealed no significant change of gain, confirming that saccade shortening adaptation is easier to elicit. Also, together with this last result, the stable gain observed in the “CONTROL” conditions of both experiments suggests that mislocalization of the target flash is not responsible for the saccade shortening adaptation demonstrated in the first group. Altogether, these findings reveal that the visual “suppression” and “mislocalization” phenomena related to saccade execution do not prevent brief visual information delivered “in-flight” from being

  16. Night Myopia Studied with an Adaptive Optics Visual Analyzer

    PubMed Central

    Artal, Pablo; Schwarz, Christina; Cánovas, Carmen; Mira-Agudelo, Alejandro

    2012-01-01

    Purpose Eyes with distant objects in focus in daylight are thought to become myopic in dim light. This phenomenon, often called “night myopia” has been studied extensively for several decades. However, despite its general acceptance, its magnitude and causes are still controversial. A series of experiments were performed to understand night myopia in greater detail. Methods We used an adaptive optics instrument operating in invisible infrared light to elucidate the actual magnitude of night myopia and its main causes. The experimental setup allowed the manipulation of the eye's aberrations (and particularly spherical aberration) as well as the use of monochromatic and polychromatic stimuli. Eight subjects with normal vision monocularly determined their best focus position subjectively for a Maltese cross stimulus at different levels of luminance, from the baseline condition of 20 cd/m2 to the lowest luminance of 22×10−6 cd/m2. While subjects performed the focusing tasks, their eye's defocus and aberrations were continuously measured with the 1050-nm Hartmann-Shack sensor incorporated in the adaptive optics instrument. The experiment was repeated for a variety of controlled conditions incorporating specific aberrations of the eye and chromatic content of the stimuli. Results We found large inter-subject variability and an average of −0.8 D myopic shift for low light conditions. The main cause responsible for night myopia was the accommodation shift occurring at low light levels. Other factors, traditionally suggested to explain night myopia, such as chromatic and spherical aberrations, have a much smaller effect in this mechanism. Conclusions An adaptive optics visual analyzer was applied to study the phenomenon of night myopia. We found that the defocus shift occurring in dim light is mainly due to accommodation errors. PMID:22768343

  17. Asymptotic Linearity of Optimal Control Modification Adaptive Law with Analytical Stability Margins

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2010-01-01

    Optimal control modification has been developed to improve robustness to model-reference adaptive control. For systems with linear matched uncertainty, optimal control modification adaptive law can be shown by a singular perturbation argument to possess an outer solution that exhibits a linear asymptotic property. Analytical expressions of phase and time delay margins for the outer solution can be obtained. Using the gradient projection operator, a free design parameter of the adaptive law can be selected to satisfy stability margins.

  18. Just-in-time Time Data Analytics and Visualization of Climate Simulations using the Bellerophon Framework

    NASA Astrophysics Data System (ADS)

    Anantharaj, V. G.; Venzke, J.; Lingerfelt, E.; Messer, B.

    2015-12-01

    Climate model simulations are used to understand the evolution and variability of earth's climate. Unfortunately, high-resolution multi-decadal climate simulations can take days to weeks to complete. Typically, the simulation results are not analyzed until the model runs have ended. During the course of the simulation, the output may be processed periodically to ensure that the model is preforming as expected. However, most of the data analytics and visualization are not performed until the simulation is finished. The lengthy time period needed for the completion of the simulation constrains the productivity of climate scientists. Our implementation of near real-time data visualization analytics capabilities allows scientists to monitor the progress of their simulations while the model is running. Our analytics software executes concurrently in a co-scheduling mode, monitoring data production. When new data are generated by the simulation, a co-scheduled data analytics job is submitted to render visualization artifacts of the latest results. These visualization output are automatically transferred to Bellerophon's data server located at ORNL's Compute and Data Environment for Science (CADES) where they are processed and archived into Bellerophon's database. During the course of the experiment, climate scientists can then use Bellerophon's graphical user interface to view animated plots and their associated metadata. The quick turnaround from the start of the simulation until the data are analyzed permits research decisions and projections to be made days or sometimes even weeks sooner than otherwise possible! The supercomputer resources used to run the simulation are unaffected by co-scheduling the data visualization jobs, so the model runs continuously while the data are visualized. Our just-in-time data visualization software looks to increase climate scientists' productivity as climate modeling moves into exascale era of computing.

  19. Visual Analytics for Complex Engineering Systems: Hybrid Visual Steering of Simulation Ensembles.

    PubMed

    Matković, Krešimir; Gračanin, Denis; Splechtna, Rainer; Jelović, Mario; Stehno, Benedikt; Hauser, Helwig; Purgathofer, Werner

    2014-12-01

    In this paper we propose a novel approach to hybrid visual steering of simulation ensembles. A simulation ensemble is a collection of simulation runs of the same simulation model using different sets of control parameters. Complex engineering systems have very large parameter spaces so a naïve sampling can result in prohibitively large simulation ensembles. Interactive steering of simulation ensembles provides the means to select relevant points in a multi-dimensional parameter space (design of experiment). Interactive steering efficiently reduces the number of simulation runs needed by coupling simulation and visualization and allowing a user to request new simulations on the fly. As system complexity grows, a pure interactive solution is not always sufficient. The new approach of hybrid steering combines interactive visual steering with automatic optimization. Hybrid steering allows a domain expert to interactively (in a visualization) select data points in an iterative manner, approximate the values in a continuous region of the simulation space (by regression) and automatically find the "best" points in this continuous region based on the specified constraints and objectives (by optimization). We argue that with the full spectrum of optimization options, the steering process can be improved substantially. We describe an integrated system consisting of a simulation, a visualization, and an optimization component. We also describe typical tasks and propose an interactive analysis workflow for complex engineering systems. We demonstrate our approach on a case study from automotive industry, the optimization of a hydraulic circuit in a high pressure common rail Diesel injection system.

  20. Space-time visual analytics of eye-tracking data for dynamic stimuli.

    PubMed

    Kurzhals, Kuno; Weiskopf, Daniel

    2013-12-01

    We introduce a visual analytics method to analyze eye movement data recorded for dynamic stimuli such as video or animated graphics. The focus lies on the analysis of data of several viewers to identify trends in the general viewing behavior, including time sequences of attentional synchrony and objects with strong attentional focus. By using a space-time cube visualization in combination with clustering, the dynamic stimuli and associated eye gazes can be analyzed in a static 3D representation. Shotbased, spatiotemporal clustering of the data generates potential areas of interest that can be filtered interactively. We also facilitate data drill-down: the gaze points are shown with density-based color mapping and individual scan paths as lines in the space-time cube. The analytical process is supported by multiple coordinated views that allow the user to focus on different aspects of spatial and temporal information in eye gaze data. Common eye-tracking visualization techniques are extended to incorporate the spatiotemporal characteristics of the data. For example, heat maps are extended to motion-compensated heat maps and trajectories of scan paths are included in the space-time visualization. Our visual analytics approach is assessed in a qualitative users study with expert users, which showed the usefulness of the approach and uncovered that the experts applied different analysis strategies supported by the system. PMID:24051779

  1. Space-time visual analytics of eye-tracking data for dynamic stimuli.

    PubMed

    Kurzhals, Kuno; Weiskopf, Daniel

    2013-12-01

    We introduce a visual analytics method to analyze eye movement data recorded for dynamic stimuli such as video or animated graphics. The focus lies on the analysis of data of several viewers to identify trends in the general viewing behavior, including time sequences of attentional synchrony and objects with strong attentional focus. By using a space-time cube visualization in combination with clustering, the dynamic stimuli and associated eye gazes can be analyzed in a static 3D representation. Shotbased, spatiotemporal clustering of the data generates potential areas of interest that can be filtered interactively. We also facilitate data drill-down: the gaze points are shown with density-based color mapping and individual scan paths as lines in the space-time cube. The analytical process is supported by multiple coordinated views that allow the user to focus on different aspects of spatial and temporal information in eye gaze data. Common eye-tracking visualization techniques are extended to incorporate the spatiotemporal characteristics of the data. For example, heat maps are extended to motion-compensated heat maps and trajectories of scan paths are included in the space-time visualization. Our visual analytics approach is assessed in a qualitative users study with expert users, which showed the usefulness of the approach and uncovered that the experts applied different analysis strategies supported by the system.

  2. Why High Performance Visual Data Analytics is both Relevant and Difficult

    SciTech Connect

    Bethel, E. Wes; Byna, Suren; Ruebel, Oliver; Wu, K. John; Wehner, Michael

    2012-12-01

    Data visualization, as well as data analysis and data analytics, are all an integral part of the scientific process. Collectively, these technologies provide the means to gain insight into data of ever-increasing size and complexity. Over the past two decades, a substantial amount of visualization, analysis, and analytics R&D has focused on the challenges posed by increasing data size and complexity, as well as on the increasing complexity of a rapidly changing computational platform landscape. While some of this research focuses on solely on technologies, such as indexing and searching or novel analysis or visualization algorithms, other R&D projects focus on applying technological advances to specific application problems. Some of the most interesting and productive results occur when these two activities R&D and application are conducted in a collaborative fashion, where application needs drive R&D, and R&D results are immediately applicable to real world problems.

  3. Visual analytical tool for evaluation of 10-year perioperative transfusion practice at a children's hospital.

    PubMed

    Gálvez, Jorge A; Ahumada, Luis; Simpao, Allan F; Lin, Elaina E; Bonafide, Christopher P; Choudhry, Dhruv; England, William R; Jawad, Abbas F; Friedman, David; Sesok-Pizzini, Debora A; Rehman, Mohamed A

    2014-01-01

    Children are a vulnerable population in the operating room, and are particularly at risk of complications from unanticipated hemorrhage. The decision to prepare blood products prior to surgery varies depending on the personal experience of the clinician caring for the patient. We present the first application of a data visualization technique to study large datasets in the context of blood product transfusions at a tertiary pediatric hospital. The visual analytical interface allows real-time interaction with datasets from 230 000 procedure records. Clinicians can use the visual analytical interface to analyze blood product usage based on procedure- and patient-specific factors, and then use that information to guide policies for ordering blood products.

  4. Visual analytics of surveillance data on foodborne vibriosis, United States, 1973-2010.

    PubMed

    Sims, Jennifer N; Isokpehi, Raphael D; Cooper, Gabrielle A; Bass, Michael P; Brown, Shyretha D; St John, Alison L; Gulig, Paul A; Cohly, Hari H P

    2011-01-01

    Foodborne illnesses caused by microbial and chemical contaminants in food are a substantial health burden worldwide. In 2007, human vibriosis (non-cholera Vibrio infections) became a notifiable disease in the United States. In addition, Vibrio species are among the 31 major known pathogens transmitted through food in the United States. Diverse surveillance systems for foodborne pathogens also track outbreaks, illnesses, hospitalization and deaths due to non-cholera vibrios. Considering the recognition of vibriosis as a notifiable disease in the United States and the availability of diverse surveillance systems, there is a need for the development of easily deployed visualization and analysis approaches that can combine diverse data sources in an interactive manner. Current efforts to address this need are still limited. Visual analytics is an iterative process conducted via visual interfaces that involves collecting information, data preprocessing, knowledge representation, interaction, and decision making. We have utilized public domain outbreak and surveillance data sources covering 1973 to 2010, as well as visual analytics software to demonstrate integrated and interactive visualizations of data on foodborne outbreaks and surveillance of Vibrio species. Through the data visualization, we were able to identify unique patterns and/or novel relationships within and across datasets regarding (i) causative agent; (ii) foodborne outbreaks and illness per state; (iii) location of infection; (iv) vehicle (food) of infection; (v) anatomical site of isolation of Vibrio species; (vi) patients and complications of vibriosis; (vii) incidence of laboratory-confirmed vibriosis and V. parahaemolyticus outbreaks. The additional use of emerging visual analytics approaches for interaction with data on vibriosis, including non-foodborne related disease, can guide disease control and prevention as well as ongoing outbreak investigations.

  5. A collaborative large spatio-temporal data visual analytics architecture for emergence response

    NASA Astrophysics Data System (ADS)

    Guo, D.; Li, J.; Cao, H.; Zhou, Y.

    2014-02-01

    The unconventional emergency, usually outbreaks more suddenly, and is diffused more quickly, but causes more secondary damage and derives more disaster than what it is usually expected. The data volume and urgency of emergency exceeds the capacity of current emergency management systems. In this paper, we propose a three-tier collaborative spatio-temporal visual analysis architecture to support emergency management. The prototype system, based on cloud computation environment, supports aggregation of massive unstructured and semi-structured data, integration of various computing model sand algorithms; collaborative visualization and visual analytics among users with a diversity of backgrounds. The distributed data in 100TB scale is integrated in a unified platform and shared with thousands of experts and government agencies by nearly 100 models. The users explore, visualize and analyse the big data and make a collaborative countermeasures to emergencies.

  6. Extracting insights from electronic health records: case studies, a visual analytics process model, and design recommendations.

    PubMed

    Wang, Taowei David; Wongsuphasawat, Krist; Plaisant, Catherine; Shneiderman, Ben

    2011-10-01

    Current electronic health record (EHR) systems facilitate the storage, retrieval, persistence, and sharing of patient data. However, the way physicians interact with EHRs has not changed much. More specifically, support for temporal analysis of a large number of EHRs has been lacking. A number of information visualization techniques have been proposed to alleviate this problem. Unfortunately, due to their limited application to a single case study, the results are often difficult to generalize across medical scenarios. We present the usage data of Lifelines2 (Wang et al. 2008), our information visualization system, and user comments, both collected over eight different medical case studies. We generalize our experience into a visual analytics process model for multiple EHRs. Based on our analysis, we make seven design recommendations to information visualization tools to explore EHR systems.

  7. Shape anomaly detection under strong measurement noise: An analytical approach to adaptive thresholding

    NASA Astrophysics Data System (ADS)

    Krasichkov, Alexander S.; Grigoriev, Eugene B.; Bogachev, Mikhail I.; Nifontov, Eugene M.

    2015-10-01

    We suggest an analytical approach to the adaptive thresholding in a shape anomaly detection problem. We find an analytical expression for the distribution of the cosine similarity score between a reference shape and an observational shape hindered by strong measurement noise that depends solely on the noise level and is independent of the particular shape analyzed. The analytical treatment is also confirmed by computer simulations and shows nearly perfect agreement. Using this analytical solution, we suggest an improved shape anomaly detection approach based on adaptive thresholding. We validate the noise robustness of our approach using typical shapes of normal and pathological electrocardiogram cycles hindered by additive white noise. We show explicitly that under high noise levels our approach considerably outperforms the conventional tactic that does not take into account variations in the noise level.

  8. Matisse: A Visual Analytics System for Exploring Emotion Trends in Social Media Text Streams

    SciTech Connect

    Steed, Chad A; Drouhard, Margaret MEG G; Beaver, Justin M; Pyle, Joshua M; BogenII, Paul L.

    2015-01-01

    Dynamically mining textual information streams to gain real-time situational awareness is especially challenging with social media systems where throughput and velocity properties push the limits of a static analytical approach. In this paper, we describe an interactive visual analytics system, called Matisse, that aids with the discovery and investigation of trends in streaming text. Matisse addresses the challenges inherent to text stream mining through the following technical contributions: (1) robust stream data management, (2) automated sentiment/emotion analytics, (3) interactive coordinated visualizations, and (4) a flexible drill-down interaction scheme that accesses multiple levels of detail. In addition to positive/negative sentiment prediction, Matisse provides fine-grained emotion classification based on Valence, Arousal, and Dominance dimensions and a novel machine learning process. Information from the sentiment/emotion analytics are fused with raw data and summary information to feed temporal, geospatial, term frequency, and scatterplot visualizations using a multi-scale, coordinated interaction model. After describing these techniques, we conclude with a practical case study focused on analyzing the Twitter sample stream during the week of the 2013 Boston Marathon bombings. The case study demonstrates the effectiveness of Matisse at providing guided situational awareness of significant trends in social media streams by orchestrating computational power and human cognition.

  9. Can Twitter Save Lives? A Broad-Scale Study on Visual Social Media Analytics for Public Safety.

    PubMed

    Thom, Dennis; Kruger, Robert; Ertl, Thomas

    2016-07-01

    The use of social media monitoring for public safety is on the brink of commercialization and practical adoption. To close the gap between research and application, this paper presents results of a two-phase study on visual analytics of social media for public safety. For the first phase, we conducted a large field study, in which 29 practitioners from disaster response and critical infrastructure management were asked to investigate crisis intelligence tasks based on Twitter data recorded during the 2013 German Flood. To this end, the ScatterBlogs visual analytics system, a platform that provides reference implementations of tools and techniques popular in research, was given to them as an integrated toolbox. We reviewed the domain experts' individual performances with the system as well as their comments about the usefulness of techniques. In the second phase, we built on this feedback about ScatterBlogs in order to sketch out a system and create additional tools specifically adapted to the collected requirements. The performance of the old lab prototype is finally compared against the re-design in a controlled user study. PMID:26841398

  10. Can Twitter Save Lives? A Broad-Scale Study on Visual Social Media Analytics for Public Safety.

    PubMed

    Thom, Dennis; Kruger, Robert; Ertl, Thomas

    2016-07-01

    The use of social media monitoring for public safety is on the brink of commercialization and practical adoption. To close the gap between research and application, this paper presents results of a two-phase study on visual analytics of social media for public safety. For the first phase, we conducted a large field study, in which 29 practitioners from disaster response and critical infrastructure management were asked to investigate crisis intelligence tasks based on Twitter data recorded during the 2013 German Flood. To this end, the ScatterBlogs visual analytics system, a platform that provides reference implementations of tools and techniques popular in research, was given to them as an integrated toolbox. We reviewed the domain experts' individual performances with the system as well as their comments about the usefulness of techniques. In the second phase, we built on this feedback about ScatterBlogs in order to sketch out a system and create additional tools specifically adapted to the collected requirements. The performance of the old lab prototype is finally compared against the re-design in a controlled user study.

  11. XCluSim: a visual analytics tool for interactively comparing multiple clustering results of bioinformatics data

    PubMed Central

    2015-01-01

    Background Though cluster analysis has become a routine analytic task for bioinformatics research, it is still arduous for researchers to assess the quality of a clustering result. To select the best clustering method and its parameters for a dataset, researchers have to run multiple clustering algorithms and compare them. However, such a comparison task with multiple clustering results is cognitively demanding and laborious. Results In this paper, we present XCluSim, a visual analytics tool that enables users to interactively compare multiple clustering results based on the Visual Information Seeking Mantra. We build a taxonomy for categorizing existing techniques of clustering results visualization in terms of the Gestalt principles of grouping. Using the taxonomy, we choose the most appropriate interactive visualizations for presenting individual clustering results from different types of clustering algorithms. The efficacy of XCluSim is shown through case studies with a bioinformatician. Conclusions Compared to other relevant tools, XCluSim enables users to compare multiple clustering results in a more scalable manner. Moreover, XCluSim supports diverse clustering algorithms and dedicated visualizations and interactions for different types of clustering results, allowing more effective exploration of details on demand. Through case studies with a bioinformatics researcher, we received positive feedback on the functionalities of XCluSim, including its ability to help identify stably clustered items across multiple clustering results. PMID:26328893

  12. DIVE: a graph-based visual-analytics framework for big data.

    PubMed

    Rysavy, Steven J; Bromley, Dennis; Daggett, Valerie

    2014-01-01

    The need for data-centric scientific tools is growing; domains such as biology, chemistry, and physics are increasingly adopting computational approaches. So, scientists must deal with the challenges of big data. To address these challenges, researchers built a visual-analytics platform named DIVE (Data Intensive Visualization Engine). DIVE is a data-agnostic, ontologically expressive software framework that can stream large datasets at interactive speeds. In particular, DIVE makes novel contributions to structured-data-model manipulation and high-throughput streaming of large, structured datasets.

  13. Visual analytics of cyber physical data streams using spatio-temporal radial pixel visualization

    NASA Astrophysics Data System (ADS)

    Hao, M.; Marwah, M.; Mittelstaedt, S.; Janetzko, H.; Keim, D.; Dayal, U.; Bash, C.; Felix, C.; Patel, C.; Hsu, M.; Chen, Y.; Hund, M.

    2013-01-01

    Cyber physical systems (CPS), such as smart buildings and data centers, are richly instrumented systems composed of tightly coupled computational and physical elements that generate large amounts of data. To explore CPS data and obtain actionable insights, we present a new approach called Radial Pixel Visualization (RPV); which uses multiple concentric rings to show the data in a compact circular layout of pixel cells, each ring containing the values for a specific variable over time and each pixel cell representing an individual data value at a specific time. RPV provides an effective visual representation of locality and periodicity of the high volume, multivariate data streams. RPVs may have an additional analysis ring for highlighting the results of correlation analysis or peak point detection. Our real-world applications demonstrate the effectiveness of this approach. The application examples show how RPV can help CPS administrators to identify periodic thermal hot spots, find root-causes of the cooling problems, understand building energy consumption, and optimize IT-services workloads.

  14. Text Stream Trend Analysis using Multiscale Visual Analytics with Applications to Social Media Systems

    SciTech Connect

    Steed, Chad A; Beaver, Justin M; BogenII, Paul L.; Drouhard, Margaret MEG G; Pyle, Joshua M

    2015-01-01

    In this paper, we introduce a new visual analytics system, called Matisse, that allows exploration of global trends in textual information streams with specific application to social media platforms. Despite the potential for real-time situational awareness using these services, interactive analysis of such semi-structured textual information is a challenge due to the high-throughput and high-velocity properties. Matisse addresses these challenges through the following contributions: (1) robust stream data management, (2) automated sen- timent/emotion analytics, (3) inferential temporal, geospatial, and term-frequency visualizations, and (4) a flexible drill-down interaction scheme that progresses from macroscale to microscale views. In addition to describing these contributions, our work-in-progress paper concludes with a practical case study focused on the analysis of Twitter 1% sample stream information captured during the week of the Boston Marathon bombings.

  15. Designing a Collaborative Visual Analytics Tool for Social and Technological Change Prediction.

    SciTech Connect

    Wong, Pak C.; Leung, Lai-Yung R.; Lu, Ning; Scott, Michael J.; Mackey, Patrick S.; Foote, Harlan P.; Correia, James; Taylor, Zachary T.; Xu, Jianhua; Unwin, Stephen D.; Sanfilippo, Antonio P.

    2009-09-01

    We describe our ongoing efforts to design and develop a collaborative visual analytics tool to interactively model social and technological change of our society in a future setting. The work involves an interdisciplinary team of scientists from atmospheric physics, electrical engineering, building engineering, social sciences, economics, public policy, and national security. The goal of the collaborative tool is to predict the impact of global climate change on the U.S. power grids and its implications for society and national security. These future scenarios provide critical assessment and information necessary for policymakers and stakeholders to help formulate a coherent, unified strategy toward shaping a safe and secure society. The paper introduces the problem background and related work, explains the motivation and rationale behind our design approach, presents our collaborative visual analytics tool and usage examples, and finally shares the development challenge and lessons learned from our investigation.

  16. Vis4Heritage: visual analytics approach on Grotto wall painting degradations.

    PubMed

    Zhang, Jiawan; Kang, Kai; Liu, Dajian; Yuan, Ye; E, Yanli

    2013-12-01

    For preserving the Grotto wall paintings and protecting these historic cultural icons from the damage and deterioration in nature environment, a visual analytics framework and a set of tools are proposed for the discovery of degradation patterns. In comparison with the traditional analysis methods that used restricted scales, our method provides users with multi-scale analytic support to study the problems on site, cave, wall and particular degradation area scales, through the application of multidimensional visualization techniques. Several case studies have been carried out using real-world wall painting data collected from a renowned World Heritage site, to verify the usability and effectiveness of the proposed method. User studies and expert reviews were also conducted through by domain experts ranging from scientists such as microenvironment researchers, archivists, geologists, chemists, to practitioners such as conservators, restorers and curators.

  17. Understanding variations in pediatric asthma care processes in the emergency department using visual analytics.

    PubMed

    Basole, Rahul C; Braunstein, Mark L; Kumar, Vikas; Park, Hyunwoo; Kahng, Minsuk; Chau, Duen Horng Polo; Tamersoy, Acar; Hirsh, Daniel A; Serban, Nicoleta; Bost, James; Lesnick, Burton; Schissel, Beth L; Thompson, Michael

    2015-03-01

    Health care delivery processes consist of complex activity sequences spanning organizational, spatial, and temporal boundaries. Care is human-directed so these processes can have wide variations in cost, quality, and outcome making systemic care process analysis, conformance testing, and improvement challenging. We designed and developed an interactive visual analytic process exploration and discovery tool and used it to explore clinical data from 5784 pediatric asthma emergency department patients.

  18. SciDAC Visualization and Analytics Center for EnablingTechnology

    SciTech Connect

    Bethel, E. Wes; Johnson, Chris; Joy, Ken; Ahern, Sean; Pascucci,Valerio; Childs, Hank; Cohen, Jonathan; Duchaineau, Mark; Hamann, Bernd; Hansen, Charles; Laney, Dan; Lindstrom, Peter; Meredith, Jeremy; Ostrouchov, George; Parker, Steven; Silva, Claudio; Sanderson, Allen; Tricoche, Xavier

    2006-11-28

    The SciDAC2 Visualization and Analytics Center for EnablingTechnologies (VACET) began operation on 10/1/2006. This document, dated11/27/2006, is the first version of the VACET project management plan. Itwas requested by and delivered to ASCR/DOE. It outlines the Center'saccomplishments in the first six weeks of operation along with broadobjectives for the upcoming future (12-24 months).

  19. The longitudinal use of SaNDVis: visual social network analytics in the enterprise.

    PubMed

    Perer, Adam; Guy, Ido; Uziel, Erel; Ronen, Inbal; Jacovi, Michal

    2013-07-01

    As people continue to author and share increasing amounts of information in social media, the opportunity to leverage such information for relationship discovery tasks increases. In this paper, we describe a set of systems that mine, aggregate, and infer a social graph from social media inside an enterprise, resulting in over 73 million relationships between 450,000 people. We then describe SaNDVis, a novel visual analytics tool that supports people-centric tasks like expertise location, team building, and team coordination in the enterprise. We provide details of a 22-month-long, large-scale deployment to over 2,300 users from which we analyze longitudinal usage patterns, classify types of visual analytics queries and users, and extract dominant use cases from log and interview data. By integrating social position, evidence, and facets into SaNDVis, we demonstrate how users can use a visual analytics tool to reflect on existing relationships as well as build new relationships in an enterprise setting. PMID:23661007

  20. The longitudinal use of SaNDVis: visual social network analytics in the enterprise.

    PubMed

    Perer, Adam; Guy, Ido; Uziel, Erel; Ronen, Inbal; Jacovi, Michal

    2013-07-01

    As people continue to author and share increasing amounts of information in social media, the opportunity to leverage such information for relationship discovery tasks increases. In this paper, we describe a set of systems that mine, aggregate, and infer a social graph from social media inside an enterprise, resulting in over 73 million relationships between 450,000 people. We then describe SaNDVis, a novel visual analytics tool that supports people-centric tasks like expertise location, team building, and team coordination in the enterprise. We provide details of a 22-month-long, large-scale deployment to over 2,300 users from which we analyze longitudinal usage patterns, classify types of visual analytics queries and users, and extract dominant use cases from log and interview data. By integrating social position, evidence, and facets into SaNDVis, we demonstrate how users can use a visual analytics tool to reflect on existing relationships as well as build new relationships in an enterprise setting.

  1. How Can Visual Analytics Assist Investigative Analysis? Design Implications from an Evaluation.

    PubMed

    Youn-Ah Kang; Görg, Carsten; Stasko, John

    2011-05-01

    Despite the growing number of systems providing visual analytic support for investigative analysis, few empirical studies of the potential benefits of such systems have been conducted, particularly controlled, comparative evaluations. Determining how such systems foster insight and sensemaking is important for their continued growth and study, however. Furthermore, studies that identify how people use such systems and why they benefit (or not) can help inform the design of new systems in this area. We conducted an evaluation of the visual analytics system Jigsaw employed in a small investigative sensemaking exercise, and compared its use to three other more traditional methods of analysis. Sixteen participants performed a simulated intelligence analysis task under one of the four conditions. Experimental results suggest that Jigsaw assisted participants to analyze the data and identify an embedded threat. We describe different analysis strategies used by study participants and how computational support (or the lack thereof) influenced the strategies. We then illustrate several characteristics of the sensemaking process identified in the study and provide design implications for investigative analysis tools based thereon. We conclude with recommendations on metrics and techniques for evaluating visual analytics systems for investigative analysis.

  2. Reinventing the Contingency Wheel: Scalable Visual Analytics of Large Categorical Data.

    PubMed

    Alsallakh, B; Aigner, W; Miksch, S; Groller, M E

    2012-12-01

    Contingency tables summarize the relations between categorical variables and arise in both scientific and business domains. Asymmetrically large two-way contingency tables pose a problem for common visualization methods. The Contingency Wheel has been recently proposed as an interactive visual method to explore and analyze such tables. However, the scalability and readability of this method are limited when dealing with large and dense tables. In this paper we present Contingency Wheel++, new visual analytics methods that overcome these major shortcomings: (1) regarding automated methods, a measure of association based on Pearson's residuals alleviates the bias of the raw residuals originally used, (2) regarding visualization methods, a frequency-based abstraction of the visual elements eliminates overlapping and makes analyzing both positive and negative associations possible, and (3) regarding the interactive exploration environment, a multi-level overview+detail interface enables exploring individual data items that are aggregated in the visualization or in the table using coordinated views. We illustrate the applicability of these new methods with a use case and show how they enable discovering and analyzing nontrivial patterns and associations in large categorical data.

  3. Visual analytics techniques for large multi-attribute time series data

    NASA Astrophysics Data System (ADS)

    Hao, Ming C.; Dayal, Umeshwar; Keim, Daniel A.

    2008-01-01

    Time series data commonly occur when variables are monitored over time. Many real-world applications involve the comparison of long time series across multiple variables (multi-attributes). Often business people want to compare this year's monthly sales with last year's sales to make decisions. Data warehouse administrators (DBAs) want to know their daily data loading job performance. DBAs need to detect the outliers early enough to act upon them. In this paper, two new visual analytic techniques are introduced: The color cell-based Visual Time Series Line Charts and Maps highlight significant changes over time in a long time series data and the new Visual Content Query facilitates finding the contents and histories of interesting patterns and anomalies, which leads to root cause identification. We have applied both methods to two real-world applications to mine enterprise data warehouse and customer credit card fraud data to illustrate the wide applicability and usefulness of these techniques.

  4. Interactive Visual Analytics Approch for Exploration of Geochemical Model Simulations with Different Parameter Sets

    NASA Astrophysics Data System (ADS)

    Jatnieks, Janis; De Lucia, Marco; Sips, Mike; Dransch, Doris

    2015-04-01

    Many geoscience applications can benefit from testing many combinations of input parameters for geochemical simulation models. It is, however, a challenge to screen the input and output data from the model to identify the significant relationships between input parameters and output variables. For addressing this problem we propose a Visual Analytics approach that has been developed in an ongoing collaboration between computer science and geoscience researchers. Our Visual Analytics approach uses visualization methods of hierarchical horizontal axis, multi-factor stacked bar charts and interactive semi-automated filtering for input and output data together with automatic sensitivity analysis. This guides the users towards significant relationships. We implement our approach as an interactive data exploration tool. It is designed with flexibility in mind, so that a diverse set of tasks such as inverse modeling, sensitivity analysis and model parameter refinement can be supported. Here we demonstrate the capabilities of our approach by two examples for gas storage applications. For the first example our Visual Analytics approach enabled the analyst to observe how the element concentrations change around previously established baselines in response to thousands of different combinations of mineral phases. This supported combinatorial inverse modeling for interpreting observations about the chemical composition of the formation fluids at the Ketzin pilot site for CO2 storage. The results indicate that, within the experimental error range, the formation fluid cannot be considered at local thermodynamical equilibrium with the mineral assemblage of the reservoir rock. This is a valuable insight from the predictive geochemical modeling for the Ketzin site. For the second example our approach supports sensitivity analysis for a reaction involving the reductive dissolution of pyrite with formation of pyrrothite in presence of gaseous hydrogen. We determine that this reaction

  5. A results-based process for evaluation of diverse visual analytics tools

    NASA Astrophysics Data System (ADS)

    Rubin, Gary; Berger, David H.

    2013-05-01

    With the pervasiveness of still and full-motion imagery in commercial and military applications, the need to ingest and analyze these media has grown rapidly in recent years. Additionally, video hosting and live camera websites provide a near real-time view of our changing world with unprecedented spatial coverage. To take advantage of these controlled and crowd-sourced opportunities, sophisticated visual analytics (VA) tools are required to accurately and efficiently convert raw imagery into usable information. Whether investing in VA products or evaluating algorithms for potential development, it is important for stakeholders to understand the capabilities and limitations of visual analytics tools. Visual analytics algorithms are being applied to problems related to Intelligence, Surveillance, and Reconnaissance (ISR), facility security, and public safety monitoring, to name a few. The diversity of requirements means that a onesize- fits-all approach to performance assessment will not work. We present a process for evaluating the efficacy of algorithms in real-world conditions, thereby allowing users and developers of video analytics software to understand software capabilities and identify potential shortcomings. The results-based approach described in this paper uses an analysis of end-user requirements and Concept of Operations (CONOPS) to define Measures of Effectiveness (MOEs), test data requirements, and evaluation strategies. We define metrics that individually do not fully characterize a system, but when used together, are a powerful way to reveal both strengths and weaknesses. We provide examples of data products, such as heatmaps, performance maps, detection timelines, and rank-based probability-of-detection curves.

  6. Network Traffic Analysis With Query Driven VisualizationSC 2005HPC Analytics Results

    SciTech Connect

    Stockinger, Kurt; Wu, Kesheng; Campbell, Scott; Lau, Stephen; Fisk, Mike; Gavrilov, Eugene; Kent, Alex; Davis, Christopher E.; Olinger,Rick; Young, Rob; Prewett, Jim; Weber, Paul; Caudell, Thomas P.; Bethel,E. Wes; Smith, Steve

    2005-09-01

    Our analytics challenge is to identify, characterize, and visualize anomalous subsets of large collections of network connection data. We use a combination of HPC resources, advanced algorithms, and visualization techniques. To effectively and efficiently identify the salient portions of the data, we rely on a multi-stage workflow that includes data acquisition, summarization (feature extraction), novelty detection, and classification. Once these subsets of interest have been identified and automatically characterized, we use a state-of-the-art-high-dimensional query system to extract data subsets for interactive visualization. Our approach is equally useful for other large-data analysis problems where it is more practical to identify interesting subsets of the data for visualization than to render all data elements. By reducing the size of the rendering workload, we enable highly interactive and useful visualizations. As a result of this work we were able to analyze six months worth of data interactively with response times two orders of magnitude shorter than with conventional methods.

  7. Adaptive Assessment of Young Children with Visual Impairment

    ERIC Educational Resources Information Center

    Ruiter, Selma; Nakken, Han; Janssen, Marleen; Van Der Meulen, Bieuwe; Looijestijn, Paul

    2011-01-01

    The aim of this study was to assess the effect of adaptations for children with low vision of the Bayley Scales, a standardized developmental instrument widely used to assess development in young children. Low vision adaptations were made to the procedures, item instructions and play material of the Dutch version of the Bayley Scales of Infant…

  8. Visual Behaviors and Adaptations Associated with Cortical and Ocular Impairment in Children.

    ERIC Educational Resources Information Center

    Jan, J. E.; Groenveld, M.

    1993-01-01

    This article shows the usefulness of understanding visual behaviors in the diagnosis of various types of visual impairments that are due to ocular and cortical disorders. Behaviors discussed include nystagmus, ocular motor dyspraxia, head position, close viewing, field loss adaptations, mannerisms, photophobia, and abnormal color perception. (JDD)

  9. Verifiable Adaptive Control with Analytical Stability Margins by Optimal Control Modification

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2010-01-01

    This paper presents a verifiable model-reference adaptive control method based on an optimal control formulation for linear uncertain systems. A predictor model is formulated to enable a parameter estimation of the system parametric uncertainty. The adaptation is based on both the tracking error and predictor error. Using a singular perturbation argument, it can be shown that the closed-loop system tends to a linear time invariant model asymptotically under an assumption of fast adaptation. A stability margin analysis is given to estimate a lower bound of the time delay margin using a matrix measure method. Using this analytical method, the free design parameter n of the optimal control modification adaptive law can be determined to meet a specification of stability margin for verification purposes.

  10. Munin: A Peer-to-Peer Middleware for Ubiquitous Analytics and Visualization Spaces.

    PubMed

    Badam, Sriram Karthik; Fisher, Eli; Elmqvist, Niklas

    2015-02-01

    We present Munin, a software framework for building ubiquitous analytics environments consisting of multiple input and output surfaces, such as tabletop displays, wall-mounted displays, and mobile devices. Munin utilizes a service-based model where each device provides one or more dynamically loaded services for input, display, or computation. Using a peer-to-peer model for communication, it leverages IP multicast to replicate the shared state among the peers. Input is handled through a shared event channel that lets input and output devices be fully decoupled. It also provides a data-driven scene graph to delegate rendering to peers, thus creating a robust, fault-tolerant, decentralized system. In this paper, we describe Munin's general design and architecture, provide several examples of how we are using the framework for ubiquitous analytics and visualization, and present a case study on building a Munin assembly for multidimensional visualization. We also present performance results and anecdotal user feedback for the framework that suggests that combining a service-oriented, data-driven model with middleware support for data sharing and event handling eases the design and execution of high performance distributed visualizations.

  11. Visual analytics for multimodal social network analysis: a design study with social scientists.

    PubMed

    Ghani, Sohaib; Kwon, Bum Chul; Lee, Seungyoon; Yi, Ji Soo; Elmqvist, Niklas

    2013-12-01

    Social network analysis (SNA) is becoming increasingly concerned not only with actors and their relations, but also with distinguishing between different types of such entities. For example, social scientists may want to investigate asymmetric relations in organizations with strict chains of command, or incorporate non-actors such as conferences and projects when analyzing coauthorship patterns. Multimodal social networks are those where actors and relations belong to different types, or modes, and multimodal social network analysis (mSNA) is accordingly SNA for such networks. In this paper, we present a design study that we conducted with several social scientist collaborators on how to support mSNA using visual analytics tools. Based on an openended, formative design process, we devised a visual representation called parallel node-link bands (PNLBs) that splits modes into separate bands and renders connections between adjacent ones, similar to the list view in Jigsaw. We then used the tool in a qualitative evaluation involving five social scientists whose feedback informed a second design phase that incorporated additional network metrics. Finally, we conducted a second qualitative evaluation with our social scientist collaborators that provided further insights on the utility of the PNLBs representation and the potential of visual analytics for mSNA. PMID:24051769

  12. The challenge of big data in public health: an opportunity for visual analytics.

    PubMed

    Ola, Oluwakemi; Sedig, Kamran

    2014-01-01

    Public health (PH) data can generally be characterized as big data. The efficient and effective use of this data determines the extent to which PH stakeholders can sufficiently address societal health concerns as they engage in a variety of work activities. As stakeholders interact with data, they engage in various cognitive activities such as analytical reasoning, decision-making, interpreting, and problem solving. Performing these activities with big data is a challenge for the unaided mind as stakeholders encounter obstacles relating to the data's volume, variety, velocity, and veracity. Such being the case, computer-based information tools are needed to support PH stakeholders. Unfortunately, while existing computational tools are beneficial in addressing certain work activities, they fall short in supporting cognitive activities that involve working with large, heterogeneous, and complex bodies of data. This paper presents visual analytics (VA) tools, a nascent category of computational tools that integrate data analytics with interactive visualizations, to facilitate the performance of cognitive activities involving big data. Historically, PH has lagged behind other sectors in embracing new computational technology. In this paper, we discuss the role that VA tools can play in addressing the challenges presented by big data. In doing so, we demonstrate the potential benefit of incorporating VA tools into PH practice, in addition to highlighting the need for further systematic and focused research.

  13. Proactive Spatiotemporal Resource Allocation and Predictive Visual Analytics for Community Policing and Law Enforcement.

    PubMed

    Malik, Abish; Maciejewski, Ross; Towers, Sherry; McCullough, Sean; Ebert, David S

    2014-12-01

    In this paper, we present a visual analytics approach that provides decision makers with a proactive and predictive environment in order to assist them in making effective resource allocation and deployment decisions. The challenges involved with such predictive analytics processes include end-users' understanding, and the application of the underlying statistical algorithms at the right spatiotemporal granularity levels so that good prediction estimates can be established. In our approach, we provide analysts with a suite of natural scale templates and methods that enable them to focus and drill down to appropriate geospatial and temporal resolution levels. Our forecasting technique is based on the Seasonal Trend decomposition based on Loess (STL) method, which we apply in a spatiotemporal visual analytics context to provide analysts with predicted levels of future activity. We also present a novel kernel density estimation technique we have developed, in which the prediction process is influenced by the spatial correlation of recent incidents at nearby locations. We demonstrate our techniques by applying our methodology to Criminal, Traffic and Civil (CTC) incident datasets.

  14. The Challenge of Big Data in Public Health: An Opportunity for Visual Analytics

    PubMed Central

    Ola, Oluwakemi; Sedig, Kamran

    2014-01-01

    Public health (PH) data can generally be characterized as big data. The efficient and effective use of this data determines the extent to which PH stakeholders can sufficiently address societal health concerns as they engage in a variety of work activities. As stakeholders interact with data, they engage in various cognitive activities such as analytical reasoning, decision-making, interpreting, and problem solving. Performing these activities with big data is a challenge for the unaided mind as stakeholders encounter obstacles relating to the data’s volume, variety, velocity, and veracity. Such being the case, computer-based information tools are needed to support PH stakeholders. Unfortunately, while existing computational tools are beneficial in addressing certain work activities, they fall short in supporting cognitive activities that involve working with large, heterogeneous, and complex bodies of data. This paper presents visual analytics (VA) tools, a nascent category of computational tools that integrate data analytics with interactive visualizations, to facilitate the performance of cognitive activities involving big data. Historically, PH has lagged behind other sectors in embracing new computational technology. In this paper, we discuss the role that VA tools can play in addressing the challenges presented by big data. In doing so, we demonstrate the potential benefit of incorporating VA tools into PH practice, in addition to highlighting the need for further systematic and focused research. PMID:24678376

  15. Proactive Spatiotemporal Resource Allocation and Predictive Visual Analytics for Community Policing and Law Enforcement.

    PubMed

    Malik, Abish; Maciejewski, Ross; Towers, Sherry; McCullough, Sean; Ebert, David S

    2014-12-01

    In this paper, we present a visual analytics approach that provides decision makers with a proactive and predictive environment in order to assist them in making effective resource allocation and deployment decisions. The challenges involved with such predictive analytics processes include end-users' understanding, and the application of the underlying statistical algorithms at the right spatiotemporal granularity levels so that good prediction estimates can be established. In our approach, we provide analysts with a suite of natural scale templates and methods that enable them to focus and drill down to appropriate geospatial and temporal resolution levels. Our forecasting technique is based on the Seasonal Trend decomposition based on Loess (STL) method, which we apply in a spatiotemporal visual analytics context to provide analysts with predicted levels of future activity. We also present a novel kernel density estimation technique we have developed, in which the prediction process is influenced by the spatial correlation of recent incidents at nearby locations. We demonstrate our techniques by applying our methodology to Criminal, Traffic and Civil (CTC) incident datasets. PMID:26356900

  16. TimeBench: a data model and software library for visual analytics of time-oriented data.

    PubMed

    Rind, Alexander; Lammarsch, Tim; Aigner, Wolfgang; Alsallakh, Bilal; Miksch, Silvia

    2013-12-01

    Time-oriented data play an essential role in many Visual Analytics scenarios such as extracting medical insights from collections of electronic health records or identifying emerging problems and vulnerabilities in network traffic. However, many software libraries for Visual Analytics treat time as a flat numerical data type and insufficiently tackle the complexity of the time domain such as calendar granularities and intervals. Therefore, developers of advanced Visual Analytics designs need to implement temporal foundations in their application code over and over again. We present TimeBench, a software library that provides foundational data structures and algorithms for time-oriented data in Visual Analytics. Its expressiveness and developer accessibility have been evaluated through application examples demonstrating a variety of challenges with time-oriented data and long-term developer studies conducted in the scope of research and student projects.

  17. Analytical and experimental study of control effort associated with model reference adaptive control

    NASA Technical Reports Server (NTRS)

    Messer, R. S.; Haftka, R. T.; Cudney, H. H.

    1992-01-01

    Numerical simulation results presently obtained for the performance of model reference adaptive control (MRAC) are experimentally verified, with a view to accounting for differences between the plant and the reference model after the control function has been brought to bear. MRAC is both experimentally and analytically applied to a single-degree-of-freedom system, as well as analytically to a MIMO system having controlled differences between the reference model and the plant. The control effort is noted to be sensitive to differences between the plant and the reference model.

  18. In vivo cellular visualization of the human retina using optical coherence tomography and adaptive optics

    SciTech Connect

    Olivier, S S; Jones, S M; Chen, D C; Zawadzki, R J; Choi, S S; Laut, S P; Werner, J S

    2006-01-05

    Optical coherence tomography (OCT) sees the human retina sharply with adaptive optics. In vivo cellular visualization of the human retina at micrometer-scale resolution is possible by enhancing Fourier-domain optical-coherence tomography with adaptive optics, which compensate for the eye's optical aberrations.

  19. Dementia alters standing postural adaptation during a visual search task in older adult men.

    PubMed

    Jor'dan, Azizah J; McCarten, J Riley; Rottunda, Susan; Stoffregen, Thomas A; Manor, Brad; Wade, Michael G

    2015-04-23

    This study investigated the effects of dementia on standing postural adaptation during performance of a visual search task. We recruited 16 older adults with dementia and 15 without dementia. Postural sway was assessed by recording medial-lateral (ML) and anterior-posterior (AP) center-of-pressure when standing with and without a visual search task; i.e., counting target letter frequency within a block of displayed randomized letters. ML sway variability was significantly higher in those with dementia during visual search as compared to those without dementia and compared to both groups during the control condition. AP sway variability was significantly greater in those with dementia as compared to those without dementia, irrespective of task condition. In the ML direction, the absolute and percent change in sway variability between the control condition and visual search (i.e., postural adaptation) was greater in those with dementia as compared to those without. In contrast, postural adaptation to visual search was similar between groups in the AP direction. As compared to those without dementia, those with dementia identified fewer letters on the visual task. In the non-dementia group only, greater increases in postural adaptation in both the ML and AP direction, correlated with lower performance on the visual task. The observed relationship between postural adaptation during the visual search task and visual search task performance--in the non-dementia group only--suggests a critical link between perception and action. Dementia reduces the capacity to perform a visual-based task while standing and thus, appears to disrupt this perception-action synergy.

  20. The role of visual analytics in asthma phenotyping and biomarker discovery.

    PubMed

    Bhavnani, Suresh K; Drake, Justin; Divekar, Rohit

    2014-01-01

    The exponential growth of biomedical data related to diseases such as asthma far exceeds our cognitive abilities to comprehend it for tasks such as biomarker discovery, pathway identification, and molecular-based phenotyping. This chapter discusses the cognitive and task-based reasons for why methods from visual analytics can help in analyzing such large and complex asthma data, and demonstrates how one such approach called network visualization and analysis can be used to reveal important translational insights related to asthma. The demonstration of the method helps to identify the strengths and limitations of network analysis, in addition to areas for future research that can enhance the use of networks to analyze vast and complex biomedical datasets related to diseases such as asthma.

  1. DecisionFlow: Visual Analytics for High-Dimensional Temporal Event Sequence Data.

    PubMed

    Gotz, David; Stavropoulos, Harry

    2014-12-01

    Temporal event sequence data is increasingly commonplace, with applications ranging from electronic medical records to financial transactions to social media activity. Previously developed techniques have focused on low-dimensional datasets (e.g., with less than 20 distinct event types). Real-world datasets are often far more complex. This paper describes DecisionFlow, a visual analysis technique designed to support the analysis of high-dimensional temporal event sequence data (e.g., thousands of event types). DecisionFlow combines a scalable and dynamic temporal event data structure with interactive multi-view visualizations and ad hoc statistical analytics. We provide a detailed review of our methods, and present the results from a 12-person user study. The study results demonstrate that DecisionFlow enables the quick and accurate completion of a range of sequence analysis tasks for datasets containing thousands of event types and millions of individual events.

  2. DIVE: A Graph-based Visual Analytics Framework for Big Data

    PubMed Central

    Rysavy, Steven J.; Bromley, Dennis; Daggett, Valerie

    2014-01-01

    The need for data-centric scientific tools is growing; domains like biology, chemistry, and physics are increasingly adopting computational approaches. As a result, scientists must now deal with the challenges of big data. To address these challenges, we built a visual analytics platform named DIVE: Data Intensive Visualization Engine. DIVE is a data-agnostic, ontologically-expressive software framework capable of streaming large datasets at interactive speeds. Here we present the technical details of the DIVE platform, multiple usage examples, and a case study from the Dynameomics molecular dynamics project. We specifically highlight our novel contributions to structured data model manipulation and high-throughput streaming of large, structured datasets. PMID:24808197

  3. Integrating Heterogeneous Healthcare Datasets and Visual Analytics for Disease Bio-surveillance and Dynamics

    SciTech Connect

    Ramanathan, Arvind; Pullum, Laura L; Steed, Chad A; Quinn, Shannon; Chennubhotla, Chakra; Parker, Tara L

    2013-01-01

    n this paper, we present an overview of the big data chal- lenges in disease bio-surveillance and then discuss the use of visual analytics for integrating data and turning it into knowl- edge. We will explore two integration scenarios: (1) combining text and multimedia sources to improve situational awareness and (2) enhancing disease spread model data with real-time bio-surveillance data. Together, the proposed integration methodologies can improve awareness about when, where and how emerging diseases can affect wide geographic regions.

  4. DiseaseAtlas: multi-facet visual analytics for online disease articles.

    PubMed

    Sun, Jimeng; Gotz, David; Cao, Nan

    2010-01-01

    Online health information portals provide valuable content to casual consumers. However, the page-oriented nature of these resources makes it difficult for users to understand the overall information space and navigate the complex relationships between various diseases. We have developed a visual analytic system named DiseaseAtlas that helps users navigate a large set of disease-related documents and understand multi-dimensional relationships for key semantic concepts such as symptoms and treatments. This paper describes several unique aspects of DiseaseAtlas and demonstrates its capabilities through a case study.

  5. AUVA - Augmented Reality Empowers Visual Analytics to explore Medical Curriculum Data.

    PubMed

    Nifakos, Sokratis; Vaitsis, Christos; Zary, Nabil

    2015-01-01

    Medical curriculum data play a key role in the structure and the organization of medical programs in Universities around the world. The effective processing and usage of these data may improve the educational environment of medical students. As a consequence, the new generation of health professionals would have improved skills from the previous ones. This study introduces the process of enhancing curriculum data by the use of augmented reality technology as a management and presentation tool. The final goal is to enrich the information presented from a visual analytics approach applied on medical curriculum data and to sustain low levels of complexity of understanding these data.

  6. Visualizing metal ions in cells: an overview of analytical techniques, approaches, and probes

    PubMed Central

    Dean, Kevin M.; Qin, Yan; Palmer, Amy E.

    2012-01-01

    Quantifying the amount and defining the location of metal ions in cells and organisms are critical steps in understanding metal homeostasis and how dyshomeostasis causes or is a consequence of disease. A number of recent advances have been made in the development and application of analytical methods to visualize metal ions in biological specimens. Here, we briefly summarize these advances before focusing in more depth on probes for examining transition metals in living cells with high spatial and temporal resolution using fluorescence microscopy. PMID:22521452

  7. Adaptation to visual stimulation modifies the burst firing property of V1 neurons.

    PubMed

    Liu, Rui-Long; Wang, Ke; Meng, Jian-Jun; Hua, Tian-Miao; Liang, Zhen; Xi, Min-Min

    2013-06-01

    The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation, but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown. Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes, and thus may carry accurate stimulus-related information. Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus. The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency (bursts/s) and burst length (spikes/burst), but increased burst duration and the interspike interval within bursts. These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections, which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.

  8. Adaptation to visual and proprioceptive rearrangement - Origin of the differential effectiveness of active and passive movements

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.

    1977-01-01

    Experiments were conducted to measure and compare the accuracy with which subjects pointed to visual targets before and after an exposure period in which they received systematic proprioceptive misinformation about the locations of visual targets. The crucial factor determining whether adaptation will be elicited is shown to be the presence of a discordance in the positional information being conveyed over two different sensory modalities. Another experiment was carried out to study the effectiveness of active and passive movements in eliciting adaptation when the subjects were exposed to a systematic discordance between the visual and proprioceptive locations of external targets without being permitted sight of their hands. Superiority of active over passive movements in producing adaptation to visual rearrangement is due to the greater accuracy of position sense information about voluntarily moved limbs, partly derived from the contribution of muscle afferent signals.

  9. Effects of Using Dynamic Mathematics Software on Preservice Mathematics Teachers' Spatial Visualization Skills: The Case of Spatial Analytic Geometry

    ERIC Educational Resources Information Center

    Kösa, Temel

    2016-01-01

    The purpose of this study was to investigate the effects of using dynamic geometry software on preservice mathematics teachers' spatial visualization skills and to determine whether spatial visualization skills can be a predictor of success in learning analytic geometry of space. The study used a quasi-experimental design with a control group.…

  10. Adaptive correction method for an OCXO and investigation of analytical cumulative time error upper bound.

    PubMed

    Zhou, Hui; Kunz, Thomas; Schwartz, Howard

    2011-01-01

    Traditional oscillators used in timing modules of CDMA and WiMAX base stations are large and expensive. Applying cheaper and smaller, albeit more inaccurate, oscillators in timing modules is an interesting research challenge. An adaptive control algorithm is presented to enhance the oscillators to meet the requirements of base stations during holdover mode. An oscillator frequency stability model is developed for the adaptive control algorithm. This model takes into account the control loop which creates the correction signal when the timing module is in locked mode. A recursive prediction error method is used to identify the system model parameters. Simulation results show that an oscillator enhanced by our adaptive control algorithm improves the oscillator performance significantly, compared with uncorrected oscillators. Our results also show the benefit of explicitly modeling the control loop. Finally, the cumulative time error upper bound of such enhanced oscillators is investigated analytically and comparison results between the analytical and simulated upper bound are provided. The results show that the analytical upper bound can serve as a practical guide for system designers. PMID:21244973

  11. Adaptive correction method for an OCXO and investigation of analytical cumulative time error upper bound.

    PubMed

    Zhou, Hui; Kunz, Thomas; Schwartz, Howard

    2011-01-01

    Traditional oscillators used in timing modules of CDMA and WiMAX base stations are large and expensive. Applying cheaper and smaller, albeit more inaccurate, oscillators in timing modules is an interesting research challenge. An adaptive control algorithm is presented to enhance the oscillators to meet the requirements of base stations during holdover mode. An oscillator frequency stability model is developed for the adaptive control algorithm. This model takes into account the control loop which creates the correction signal when the timing module is in locked mode. A recursive prediction error method is used to identify the system model parameters. Simulation results show that an oscillator enhanced by our adaptive control algorithm improves the oscillator performance significantly, compared with uncorrected oscillators. Our results also show the benefit of explicitly modeling the control loop. Finally, the cumulative time error upper bound of such enhanced oscillators is investigated analytically and comparison results between the analytical and simulated upper bound are provided. The results show that the analytical upper bound can serve as a practical guide for system designers.

  12. Adaptation of a Visual Readability Instrument to Multimedia Format.

    ERIC Educational Resources Information Center

    Vrasidas, Charalambos; Lantz, Chris

    This paper describes a study in which a Picture Readability Index (PRI) was used to investigate initial and extended perceptions of photographs. Readability criteria for evaluating instructional text seems to have been in place for a long time, yet instructional visuals like photographs and illustrations have typically been subject to no such…

  13. Analytical modeling and active vibration suppression of adaptive composite panels with optimal actuator configurations

    NASA Astrophysics Data System (ADS)

    Yan, Su; Ghasemi-Nejhad, Mehrdad N.

    2007-12-01

    In this paper, models of adaptive composite panels with surface-mounted/embedded piezoelectric patches are analytically built using the Lagrange-Rayleigh-Ritz method (LRRM), verified through experiments and finite element method (FEM), and used in piezoelectric actuator placement optimization and vibration control. Two panels are considered: a cantilevered adaptive composite beam (ACB) and an adaptive circular composite plate (ACCP) with complex boundaries. The inertia and stiffness of the surface-mounted/embedded piezoelectric patches are included in the developed models. To obtain the mode shapes of the ACCP, which are essential to the LRRM modeling, the method of separation of variables is employed and Bessel series and modified Bessel series are introduced. The built models are verified by experiments for the ACB and by the FEM for the ACCP. The actuation configurations of the piezoelectric patches in the panels are optimized based on the introduced analytical model. Finally, with the optimal locations of the piezoelectric patches, the vibration suppression of the ACB and the ACCP is experimentally and numerically carried out, and excellent vibration suppressions for both adaptive panels are obtained.

  14. Combining analytical frameworks to assess livelihood vulnerability to climate change and analyse adaptation options☆

    PubMed Central

    Reed, M.S.; Podesta, G.; Fazey, I.; Geeson, N.; Hessel, R.; Hubacek, K.; Letson, D.; Nainggolan, D.; Prell, C.; Rickenbach, M.G.; Ritsema, C.; Schwilch, G.; Stringer, L.C.; Thomas, A.D.

    2013-01-01

    Experts working on behalf of international development organisations need better tools to assist land managers in developing countries maintain their livelihoods, as climate change puts pressure on the ecosystem services that they depend upon. However, current understanding of livelihood vulnerability to climate change is based on a fractured and disparate set of theories and methods. This review therefore combines theoretical insights from sustainable livelihoods analysis with other analytical frameworks (including the ecosystem services framework, diffusion theory, social learning, adaptive management and transitions management) to assess the vulnerability of rural livelihoods to climate change. This integrated analytical framework helps diagnose vulnerability to climate change, whilst identifying and comparing adaptation options that could reduce vulnerability, following four broad steps: i) determine likely level of exposure to climate change, and how climate change might interact with existing stresses and other future drivers of change; ii) determine the sensitivity of stocks of capital assets and flows of ecosystem services to climate change; iii) identify factors influencing decisions to develop and/or adopt different adaptation strategies, based on innovation or the use/substitution of existing assets; and iv) identify and evaluate potential trade-offs between adaptation options. The paper concludes by identifying interdisciplinary research needs for assessing the vulnerability of livelihoods to climate change. PMID:25844020

  15. Visual analytics for semantic queries of TerraSAR-X image content

    NASA Astrophysics Data System (ADS)

    Espinoza-Molina, Daniela; Alonso, Kevin; Datcu, Mihai

    2015-10-01

    With the continuous image product acquisition of satellite missions, the size of the image archives is considerably increasing every day as well as the variety and complexity of their content, surpassing the end-user capacity to analyse and exploit them. Advances in the image retrieval field have contributed to the development of tools for interactive exploration and extraction of the images from huge archives using different parameters like metadata, key-words, and basic image descriptors. Even though we count on more powerful tools for automated image retrieval and data analysis, we still face the problem of understanding and analyzing the results. Thus, a systematic computational analysis of these results is required in order to provide to the end-user a summary of the archive content in comprehensible terms. In this context, visual analytics combines automated analysis with interactive visualizations analysis techniques for an effective understanding, reasoning and decision making on the basis of very large and complex datasets. Moreover, currently several researches are focused on associating the content of the images with semantic definitions for describing the data in a format to be easily understood by the end-user. In this paper, we present our approach for computing visual analytics and semantically querying the TerraSAR-X archive. Our approach is mainly composed of four steps: 1) the generation of a data model that explains the information contained in a TerraSAR-X product. The model is formed by primitive descriptors and metadata entries, 2) the storage of this model in a database system, 3) the semantic definition of the image content based on machine learning algorithms and relevance feedback, and 4) querying the image archive using semantic descriptors as query parameters and computing the statistical analysis of the query results. The experimental results shows that with the help of visual analytics and semantic definitions we are able to explain

  16. Adaptation of visual spectra and opsin genes in seabreams.

    PubMed

    Wang, Feng Yu; Yan, Hong Young; Chen, Johnny Shou-Chung; Wang, Tzi Yuan; Wang, Daryi

    2009-07-01

    Three species of seabreams, Acanthopagrus berda, Acanthopagrus schlegelii and Pagrus major, living at different depths, were chosen to investigate how visual spectra and opsin genes evolve in response to various photic environments. The lambda max of photoreceptors and opsin genes were measured and cloned from these species. Eight to twelve nm spectral shifts in the rod and blue cone cells were observed between the deep-sea, P. major, and shallow-sea species, A. berda and A. schlegelii. Furthermore, the deep-sea P. major has lost its red light vision. Six opsin genes, Rh1, Rh2A, Rh2B, SWS1, SWS2 and LWS, were identified from all three seabream species, with the LWS genes of P. major having undergone pseudogenization. These data indicate that the photic environment of habitats select for the physiology of visual spectra and coding of opsin genes.

  17. VAET: A Visual Analytics Approach for E-Transactions Time-Series.

    PubMed

    Xie, Cong; Chen, Wei; Huang, Xinxin; Hu, Yueqi; Barlowe, Scott; Yang, Jing

    2014-12-01

    Previous studies on E-transaction time-series have mainly focused on finding temporal trends of transaction behavior. Interesting transactions that are time-stamped and situation-relevant may easily be obscured in a large amount of information. This paper proposes a visual analytics system, Visual Analysis of E-transaction Time-Series (VAET), that allows the analysts to interactively explore large transaction datasets for insights about time-varying transactions. With a set of analyst-determined training samples, VAET automatically estimates the saliency of each transaction in a large time-series using a probabilistic decision tree learner. It provides an effective time-of-saliency (TOS) map where the analysts can explore a large number of transactions at different time granularities. Interesting transactions are further encoded with KnotLines, a compact visual representation that captures both the temporal variations and the contextual connection of transactions. The analysts can thus explore, select, and investigate knotlines of interest. A case study and user study with a real E-transactions dataset (26 million records) demonstrate the effectiveness of VAET. PMID:26356888

  18. A Time-Critical Adaptive Approach for Visualizing Natural Scenes on Different Devices

    PubMed Central

    Dong, Tianyang; Liu, Siyuan; Xia, Jiajia; Fan, Jing; Zhang, Ling

    2015-01-01

    To automatically adapt to various hardware and software environments on different devices, this paper presents a time-critical adaptive approach for visualizing natural scenes. In this method, a simplified expression of a tree model is used for different devices. The best rendering scheme is intelligently selected to generate a particular scene by estimating the rendering time of trees based on their visual importance. Therefore, this approach can ensure the reality of natural scenes while maintaining a constant frame rate for their interactive display. To verify its effectiveness and flexibility, this method is applied in different devices, such as a desktop computer, laptop, iPad and smart phone. Applications show that the method proposed in this paper can not only adapt to devices with different computing abilities and system resources very well but can also achieve rather good visual realism and a constant frame rate for natural scenes. PMID:25723177

  19. Visually induced adaptation in three-dimensional organization of primate vestibuloocular reflex

    NASA Technical Reports Server (NTRS)

    Angelaki, D. E.; Hess, B. J.

    1998-01-01

    The adaptive plasticity of the spatial organization of the vestibuloocular reflex (VOR) has been investigated in intact and canal-plugged primates using 2-h exposure to conflicting visual (optokinetic, OKN) and vestibular rotational stimuli about mutually orthogonal axes (generating torsional VOR + vertical OKN, torsional VOR + horizontal OKN, vertical VOR + horizontal OKN, and horizontal VOR + vertical OKN). Adaptation protocols with 0.5-Hz (+/-18 degrees ) head movements about either an earth-vertical or an earth-horizontal axis induced orthogonal response components as high as 40-70% of those required for ideal adaptation. Orthogonal response gains were highest at the adapting frequency with phase leads present at lower and phase lags present at higher frequencies. Furthermore, the time course of adaptation, as well as orthogonal response dynamics were similar and relatively independent of the particular visual/vestibular stimulus combination. Low-frequency (0. 05 Hz, vestibular stimulus: +/-60 degrees ; optokinetic stimulus: +/-180 degrees ) adaptation protocols with head movements about an earth-vertical axis induced smaller orthogonal response components that did not exceed 20-40% of the head velocity stimulus (i.e., approximately 10% of that required for ideal adaptation). At the same frequency, adaptation with head movements about an earth-horizontal axis generated large orthogonal responses that reached values as high as 100-120% of head velocity after 2 h of adaptation (i.e., approximately 40% of ideal adaptation gains). The particular spatial and temporal response characteristics after low-frequency, earth-horizontal axis adaptation in both intact and canal-plugged animals strongly suggests that the orienting (and perhaps translational) but not inertial (velocity storage) components of the primate otolith-ocular system exhibit spatial adaptability. Due to the particular nested arrangement of the visual and vestibular stimuli, the optic flow pattern

  20. Adaptation to a simulated central scotoma during visual search training.

    PubMed

    Walsh, David V; Liu, Lei

    2014-03-01

    Patients with a central scotoma usually use a preferred retinal locus (PRL) consistently in daily activities. The selection process and time course of the PRL development are not well understood. We used a gaze-contingent display to simulate an isotropic central scotoma in normal subjects while they were practicing a difficult visual search task. As compared to foveal search, initial exposure to the simulated scotoma resulted in prolonged search reaction time, many more fixations and unorganized eye movements during search. By the end of a 1782-trial training with the simulated scotoma, the search performance improved to within 25% of normal foveal search. Accompanying the performance improvement, there were also fewer fixations, fewer repeated fixations in the same area of the search stimulus and a clear tendency of using one area near the border of the scotoma to identify the search target. The results were discussed in relation to natural development of PRL in central scotoma patients and potential visual training protocols to facilitate PRL development. PMID:24456805

  1. Yoga-teaching protocol adapted for children with visual impairment

    PubMed Central

    Mohanty, Soubhagyalaxmi; Hankey, Alex; Pradhan, Balaram; Ranjita, Rajashree

    2016-01-01

    Context: Childhood visual deficiency impairs children's neuro-psychomotor development, considerably affecting physical, mental, social, and emotional health. Yoga's multifaceted approach may help children with visual impairment (VI) to cope with their challenges. Aim: This study aimed to develop a special protocol for teaching yoga to children with VI, and to evaluate their preferred method of learning. Methods: The study was carried out at Ramana Maharishi Academy for the Blind, Bengaluru, South India. Forty-one students volunteered to learn yoga practices, and classes were held weekly 5 days, 1 hr per session for 16 weeks. The study introduced a new method using a sequence of five teaching steps: verbal instructions, tactile modeling, step-by-step teaching, learning in a group, and physical guidance. A questionnaire concerning the preferred steps of learning was then given to each student, and verbal answers were obtained. Results: A total of 33 (out of 41), aged 11.97 ± 1.94, 15 girls and 18 boys responded. Twenty-six (78.79%) chose physical guidance as their most favored learning mode. Conclusions: Specially designed protocol may pave the way to impart yoga in an exciting and comfortable way to children with VI. More studies are needed to further investigate the effectiveness of this new yoga protocol in similar settings. PMID:27512318

  2. Optic Flow Dominates Visual Scene Polarity in Causing Adaptive Modification of Locomotor Trajectory

    NASA Technical Reports Server (NTRS)

    Nomura, Y.; Mulavara, A. P.; Richards, J. T.; Brady, R.; Bloomberg, Jacob J.

    2005-01-01

    Locomotion and posture are influenced and controlled by vestibular, visual and somatosensory information. Optic flow and scene polarity are two characteristics of a visual scene that have been identified as being critical in how they affect perceived body orientation and self-motion. The goal of this study was to determine the role of optic flow and visual scene polarity on adaptive modification in locomotor trajectory. Two computer-generated virtual reality scenes were shown to subjects during 20 minutes of treadmill walking. One scene was a highly polarized scene while the other was composed of objects displayed in a non-polarized fashion. Both virtual scenes depicted constant rate self-motion equivalent to walking counterclockwise around the perimeter of a room. Subjects performed Stepping Tests blindfolded before and after scene exposure to assess adaptive changes in locomotor trajectory. Subjects showed a significant difference in heading direction, between pre and post adaptation stepping tests, when exposed to either scene during treadmill walking. However, there was no significant difference in the subjects heading direction between the two visual scene polarity conditions. Therefore, it was inferred from these data that optic flow has a greater role than visual polarity in influencing adaptive locomotor function.

  3. AVES: an adaptive optics visual echelle spectrograph for the VLT

    NASA Astrophysics Data System (ADS)

    Pasquini, Luca; Delabre, Bernard; Avila, Gerardo; Bonaccini, Domenico

    1998-07-01

    We present the preliminary study of a low cost, high performance spectrograph for the VLT, for observations in the V, R and I bands. This spectrograph is meant for intermediate (R equals 16,000) resolution spectroscopy of faint (sky and/or detector limited) sources, with particular emphasis on the study of solar-type (F-G) stars belonging to the nearest galaxies and to distant (or highly reddened) galactic clusters. The spectrograph is designed to use the adaptive optics (AO) systems at the VLT Telescope. Even if these AO systems will not provide diffraction limited images in the V, R and I bands, the photon concentration will still be above approximately 60% of the flux in an 0.3 arcsecond aperture for typical Paranal conditions. This makes the construction of a compact, cheap and efficient echelle spectrograph possible. AVES will outperform comparable non adaptive optic instruments by more than one magnitude for sky- and/or detector-limited observations, and it will be very suitable for observations in crowded fields.

  4. Tensor dissimilarity based adaptive seeding algorithm for DT-MRI visualization with streamtubes

    NASA Astrophysics Data System (ADS)

    Weldeselassie, Yonas T.; Hamarneh, Ghassan; Weiskopf, Daniel

    2007-03-01

    In this paper, we propose an adaptive seeding strategy for visualization of diffusion tensor magnetic resonance imaging (DT-MRI) data using streamtubes. DT-MRI is a medical imaging modality that captures unique water diffusion properties and fiber orientation information of the imaged tissues. Visualizing DT-MRI data using streamtubes has the advantage that not only the anisotropic nature of the diffusion is visualized but also the underlying anatomy of biological structures is revealed. This makes streamtubes significant for the analysis of fibrous tissues in medical images. In order to avoid rendering multiple similar streamtubes, an adaptive seeding strategy is employed which takes into account similarity of tensors in a given region. The goal is to automate the process of generating seed points such that regions with dissimilar tensors are assigned more seed points compared to regions with similar tensors. The algorithm is based on tensor dissimilarity metrics that take into account both diffusion magnitudes and directions to optimize the seeding positions and density of streamtubes in order to reduce the visual clutter. Two recent advances in tensor calculus and tensor dissimilarity metrics are utilized: the Log-Euclidean and the J-divergence. Results show that adaptive seeding not only helps to cull unnecessary streamtubes that would obscure visualization but also do so without having to compute the culled streamtubes, which makes the visualization process faster.

  5. Adaptive-mesh-based algorithm for fluorescence molecular tomography using an analytical solution.

    PubMed

    Wang, Daifa; Song, Xiaolei; Bai, Jing

    2007-07-23

    Fluorescence molecular tomography (FMT) has become an important method for in-vivo imaging of small animals. It has been widely used for tumor genesis, cancer detection, metastasis, drug discovery, and gene therapy. In this study, an algorithm for FMT is proposed to obtain accurate and fast reconstruction by combining an adaptive mesh refinement technique and an analytical solution of diffusion equation. Numerical studies have been performed on a parallel plate FMT system with matching fluid. The reconstructions obtained show that the algorithm is efficient in computation time, and they also maintain image quality.

  6. Human terrain exploitation suite: applying visual analytics to open source information.

    NASA Astrophysics Data System (ADS)

    Hanratty, Timothy; Richardson, John; Mittrick, Mark; Dumer, John; Heilman, Eric; Roy, Heather; Kase, Sue

    2014-05-01

    This paper presents the concept development and demonstration of the Human Terrain Exploitation Suite (HTES) under development at the U.S. Army Research Laboratory's Tactical Information Fusion Branch. The HTES is an amalgamation of four complementary visual analytic capabilities that target the exploitation of open source information. Open source information, specifically news feeds, blogs and other social media, provide a unique opportunity to collect and examine salient topics and trends. Analysis of open source information provides valuable insights into determining opinions, values, cultural nuances and other socio-political aspects within a military area of interest. The early results of the HTES field study indicate that the tools greatly increased the analysts' ability to exploit open source information, but improvement through greater cross-tool integration and correlation of their results is necessary for further advances.

  7. 'Connecting the dots': leveraging visual analytics to make sense of patient safety event reports.

    PubMed

    Ratwani, Raj M; Fong, Allan

    2015-03-01

    An increasing number of healthcare providers are adopting patient safety event reporting systems, yet leveraging these data to improve safety remains a challenge, particularly with large datasets composed of thousands of event reports. A MedStar Health research team, with expertise in data analytics and human factors, developed intuitive visualization dashboards to facilitate data exploration and trend analysis. Dashboards were developed using an iterative design and development process that was end-user focused. A system level dashboard, representing data from multiple hospitals, and a hospital level dashboard were developed. The dashboards allowed users to directly manipulate the data, provided coordinated displays in different formats, and allowed users to quickly zoom in on specific variables of interest. Overall feedback was incredibly positive with nearly all users wanting to adopt the system immediately. Several improvements were suggested and are discussed. The success of this approach highlights the need for more intuitive data analysis tools.

  8. Tailoring the visual communication of climate projections for local adaptation practitioners in Germany and the UK.

    PubMed

    Lorenz, Susanne; Dessai, Suraje; Forster, Piers M; Paavola, Jouni

    2015-11-28

    Visualizations are widely used in the communication of climate projections. However, their effectiveness has rarely been assessed among their target audience. Given recent calls to increase the usability of climate information through the tailoring of climate projections, it is imperative to assess the effectiveness of different visualizations. This paper explores the complexities of tailoring through an online survey conducted with 162 local adaptation practitioners in Germany and the UK. The survey examined respondents' assessed and perceived comprehension (PC) of visual representations of climate projections as well as preferences for using different visualizations in communicating and planning for a changing climate. Comprehension and use are tested using four different graph formats, which are split into two pairs. Within each pair the information content is the same but is visualized differently. We show that even within a fairly homogeneous user group, such as local adaptation practitioners, there are clear differences in respondents' comprehension of and preference for visualizations. We do not find a consistent association between assessed comprehension and PC or use within the two pairs of visualizations that we analysed. There is, however, a clear link between PC and use of graph format. This suggests that respondents use what they think they understand the best, rather than what they actually understand the best. These findings highlight that audience-specific targeted communication may be more complex and challenging than previously recognized. PMID:26460109

  9. Tailoring the visual communication of climate projections for local adaptation practitioners in Germany and the UK

    PubMed Central

    Lorenz, Susanne; Dessai, Suraje; Forster, Piers M.; Paavola, Jouni

    2015-01-01

    Visualizations are widely used in the communication of climate projections. However, their effectiveness has rarely been assessed among their target audience. Given recent calls to increase the usability of climate information through the tailoring of climate projections, it is imperative to assess the effectiveness of different visualizations. This paper explores the complexities of tailoring through an online survey conducted with 162 local adaptation practitioners in Germany and the UK. The survey examined respondents’ assessed and perceived comprehension (PC) of visual representations of climate projections as well as preferences for using different visualizations in communicating and planning for a changing climate. Comprehension and use are tested using four different graph formats, which are split into two pairs. Within each pair the information content is the same but is visualized differently. We show that even within a fairly homogeneous user group, such as local adaptation practitioners, there are clear differences in respondents’ comprehension of and preference for visualizations. We do not find a consistent association between assessed comprehension and PC or use within the two pairs of visualizations that we analysed. There is, however, a clear link between PC and use of graph format. This suggests that respondents use what they think they understand the best, rather than what they actually understand the best. These findings highlight that audience-specific targeted communication may be more complex and challenging than previously recognized. PMID:26460109

  10. Visual search disorders in acute and chronic homonymous hemianopia: lesion effects and adaptive strategies.

    PubMed

    Machner, Björn; Sprenger, Andreas; Sander, Thurid; Heide, Wolfgang; Kimmig, Hubert; Helmchen, Christoph; Kömpf, Detlef

    2009-05-01

    Patients with homonymous hemianopia due to occipital brain lesions show disorders of visual search. In everyday life this leads to difficulties in reading and spatial orientation. It is a matter of debate whether these disorders are due to the brain lesion or rather reflect compensatory eye movement strategies developing over time. For the first time, eye movements of acute hemianopic patients (n= 9) were recorded during the first days following stroke while they performed an exploratory visual-search task. Compared to age-matched control subjects their search duration was prolonged due to increased fixations and refixations, that is, repeated scanning of previously searched locations. Saccadic amplitudes were smaller in patients. Right hemianopic patients were more impaired than left hemianopic patients. The number of fixations and refixations did not differ significantly between both hemifields in the patients. Follow-up of one patient revealed changes of visual search over 18 months. By using more structured scanpaths with fewer saccades his search duration decreased. Furthermore, he developed a more efficient eye-movement strategy by making larger but less frequent saccades toward his blind side. In summary, visual-search behavior of acute hemianopic patients differs from healthy control subjects and from chronic hemianopic patients. We conclude that abnormal visual search in acute hemianopic patients is related to the brain lesion. We provide some evidence for adaptive eye-movement strategies developed over time. These adaptive strategies make the visual search more efficient and may help to compensate for the persisting visual-field loss.

  11. Tailoring the visual communication of climate projections for local adaptation practitioners in Germany and the UK.

    PubMed

    Lorenz, Susanne; Dessai, Suraje; Forster, Piers M; Paavola, Jouni

    2015-11-28

    Visualizations are widely used in the communication of climate projections. However, their effectiveness has rarely been assessed among their target audience. Given recent calls to increase the usability of climate information through the tailoring of climate projections, it is imperative to assess the effectiveness of different visualizations. This paper explores the complexities of tailoring through an online survey conducted with 162 local adaptation practitioners in Germany and the UK. The survey examined respondents' assessed and perceived comprehension (PC) of visual representations of climate projections as well as preferences for using different visualizations in communicating and planning for a changing climate. Comprehension and use are tested using four different graph formats, which are split into two pairs. Within each pair the information content is the same but is visualized differently. We show that even within a fairly homogeneous user group, such as local adaptation practitioners, there are clear differences in respondents' comprehension of and preference for visualizations. We do not find a consistent association between assessed comprehension and PC or use within the two pairs of visualizations that we analysed. There is, however, a clear link between PC and use of graph format. This suggests that respondents use what they think they understand the best, rather than what they actually understand the best. These findings highlight that audience-specific targeted communication may be more complex and challenging than previously recognized.

  12. Adapting relative phase of bimanual isometric force coordination through scaling visual information intermittency.

    PubMed

    Lafe, Charley W; Pacheco, Matheus M; Newell, Karl M

    2016-06-01

    Visual information plays an adaptive role in the relation between bimanual force coupling and error corrective processes of isometric force control. In the present study, the evolving distribution of the relative phase properties of bimanual isometric force coupling was examined by scaling within a trial the temporal feedback rate of visual intermittency (short to long presentation intervals and vice versa). The force error (RMSE) was reduced, and time-dependent irregularity (SampEn) of the force output was increased with greater amounts of visual information (shorter intermittency). Multi-stable coordination patterns of bimanual isometric force control were differentially shifted toward and away from the intrinsic dynamics by the changing the intermittency of visual information. The distribution of Hilbert transformed relative phase values showed progressively a predominantly anti-phase mode under less intermittent visual information to predominantly an in-phase mode with limited (almost no) visual information. Correlation between the hands showed a continuous reduction, rather than abrupt "transition," with increase in visual information, although no mean negative correlation was realized, despite the tendency towards an anti-phase distribution. Lastly, changes in both the performance outcome and bimanual isometric force coordination occurred at visual feedback rates faster than the minimal visual processing times established from single limb movement and isometric force protocols.

  13. Aging, visual information, and adaptation to task asymmetry in bimanual force coordination.

    PubMed

    Hu, Xiaogang; Newell, Karl M

    2011-12-01

    This study investigated the coordination and control strategies that the elderly adopt during a redundant finger force coordination task and how the amount of visual information regulates the coordination patterns. Three age groups (20-24, 65-69, and 75-79 yr) performed a bimanual asymmetric force task. Task asymmetry was manipulated via imposing different coefficients on the finger forces such that the weighted sum of the two index finger forces equaled the total force. The amount of visual information was manipulated by changing the visual information gain of the total force output. Two hypotheses were tested: the reduced adaptability hypothesis predicts that the elderly show less degree of force asymmetry between hands compared with young adults in the asymmetric coefficient conditions, whereas the compensatory hypothesis predicts that the elderly exhibit more asymmetric force coordination patterns with asymmetric coefficients. Under the compensatory hypothesis, two contrasting directions of force sharing strategies (i.e., more efficient coordination strategy and minimum variance strategy) are expected. A deteriorated task performance (high performance error and force variability) was found in the two elderly groups, but enhanced visual information improved the task performance in all age groups. With low visual information gain, the elderly showed reduced adaptability (i.e., less asymmetric forces between hands) to the unequal weighting coefficients, which supported the reduced adaptability hypothesis; however, the elderly revealed the same degree of adaptation as the young group under high visual gain. The findings are consistent with the notion that the age-related reorganization of force coordination and control patterns is mediated by visual information and, more generally, the interactive influence of multiple categories of constraints.

  14. Entropy-based heavy tailed distribution transformation and visual analytics for monitoring massive network traffic

    NASA Astrophysics Data System (ADS)

    Han, Keesook J.; Hodge, Matthew; Ross, Virginia W.

    2011-06-01

    For monitoring network traffic, there is an enormous cost in collecting, storing, and analyzing network traffic datasets. Data mining based network traffic analysis has a growing interest in the cyber security community, but is computationally expensive for finding correlations between attributes in massive network traffic datasets. To lower the cost and reduce computational complexity, it is desirable to perform feasible statistical processing on effective reduced datasets instead of on the original full datasets. Because of the dynamic behavior of network traffic, traffic traces exhibit mixtures of heavy tailed statistical distributions or overdispersion. Heavy tailed network traffic characterization and visualization are important and essential tasks to measure network performance for the Quality of Services. However, heavy tailed distributions are limited in their ability to characterize real-time network traffic due to the difficulty of parameter estimation. The Entropy-Based Heavy Tailed Distribution Transformation (EHTDT) was developed to convert the heavy tailed distribution into a transformed distribution to find the linear approximation. The EHTDT linearization has the advantage of being amenable to characterize and aggregate overdispersion of network traffic in realtime. Results of applying the EHTDT for innovative visual analytics to real network traffic data are presented.

  15. Visual and analytical strategies in spatial visualisation: perspectives from bilateral symmetry and reflection

    NASA Astrophysics Data System (ADS)

    Ramful, Ajay; Ho, Siew Yin; Lowrie, Tom

    2015-12-01

    This inquiry presents two fine-grained case studies of students demonstrating different levels of cognitive functioning in relation to bilateral symmetry and reflection. The two students were asked to solve four sets of tasks and articulate their reasoning in task-based interviews. The first participant, Brittany, focused essentially on three criteria, namely (1) equidistance, (2) congruence of sides and (3) `exactly opposite' as the intuitive counterpart of perpendicularity for performing reflection. On the other hand, the second participant, Sara, focused on perpendicularity and equidistance, as is the normative procedure. Brittany's inadequate knowledge of reflection shaped her actions and served as a validation for her solutions. Intuitively, her visual strategies took over as a fallback measure to maintain congruence of sides in the absence of a formal notion of perpendicularity. In this paper, we address some of the well-known constraints that students encounter in dealing with bilateral symmetry and reflection, particularly situations involving inclined line of symmetry. Importantly, we make an attempt to show how visual and analytical strategies interact in the production of a reflected image. Our findings highlight the necessity to give more explicit attention to the notion of perpendicularity in bilateral symmetry and reflection tasks.

  16. Visual analytics of phosphorylation time-series data on insulin response

    NASA Astrophysics Data System (ADS)

    Ma, David K. G.; Stolte, Christian; Kaur, Sandeep; Bain, Michael; O'Donoghue, Seán I.

    2013-10-01

    Visual analysis of time-series data on protein phosphorylation presents a particular challenge: bioinformatics tools currently available for visualising 'omics' data in time series have been developed primarily to study gene expression, and cannot easily be adopted to phosphorylation data, where a single protein typically has multiple phosphosites. In this study, we worked with an experimental research group that is applying very recent methods in high-throughput experimental proteomics to study the time course of protein phosphorylation events in human cells in vitro following stimulation by insulin, as part of a broader study of diabetes and obesity. We applied several existing visual analytics approaches with the goal of organising the data to facilitate new insight into underlying molecular processes. We developed a novel layout strategy called 'Minardo' that is loosely based on cell topology and ordered by time and causality. This layout utilises a frame of reference familiar to life scientists and helpful for organising and interpreting time-series data. This strategy proved to be useful, leading to new insights into the insulin response pathway. We are working on generalising the Minardo layout to accommodate similar datasets related to other signalling pathways, which should be straightforward.

  17. Morphological Processing as We Know It: An Analytical Review of Morphological Effects in Visual Word Identification

    PubMed Central

    Amenta, Simona; Crepaldi, Davide

    2012-01-01

    The last 40 years have witnessed a growing interest in the mechanisms underlying the visual identification of complex words. A large amount of experimental data has been amassed, but although a growing number of studies are proposing explicit theoretical models for their data, no comprehensive theory has gained substantial agreement among scholars in the field. We believe that this is due, at least in part, to the presence of several controversial pieces of evidence in the literature and, consequently, to the lack of a well-defined set of experimental facts that any theory should be able to explain. With this review, we aim to delineate the state of the art in the research on the visual identification of complex words. By reviewing major empirical evidences in a number of different paradigms such as lexical decision, word naming, and masked and unmasked priming, we were able to identify a series of effects that we judge as reliable or that were consistently replicated in different experiments, along with some more controversial data, which we have tried to resolve and explain. We concentrated on behavioral and electrophysiological studies on inflected, derived, and compound words, so as to span over all types of complex words. The outcome of this work is an analytical summary of well-established facts on the most relevant morphological issues, such as regularity, morpheme position coding, family size, semantic transparency, morpheme frequency, suffix allomorphy, and productivity, morphological entropy, and morpho-orthographic parsing. In discussing this set of benchmark effects, we have drawn some methodological considerations on why contrasting evidence might have emerged, and have tried to delineate a target list for the construction of a new all-inclusive model of the visual identification of morphologically complex words. PMID:22807919

  18. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets

    PubMed Central

    Angulo, Diego A.; Schneider, Cyril; Oliver, James H.; Charpak, Nathalie; Hernandez, Jose T.

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data. PMID:27601990

  19. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets.

    PubMed

    Angulo, Diego A; Schneider, Cyril; Oliver, James H; Charpak, Nathalie; Hernandez, Jose T

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data.

  20. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets

    PubMed Central

    Angulo, Diego A.; Schneider, Cyril; Oliver, James H.; Charpak, Nathalie; Hernandez, Jose T.

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data.

  1. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets.

    PubMed

    Angulo, Diego A; Schneider, Cyril; Oliver, James H; Charpak, Nathalie; Hernandez, Jose T

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data. PMID:27601990

  2. Toward a Shared Vocabulary for Visual Analysis: An Analytic Toolkit for Deconstructing the Visual Design of Graphic Novels

    ERIC Educational Resources Information Center

    Connors, Sean P.

    2012-01-01

    Literacy educators might advocate using graphic novels to develop students' visual literacy skills, but teachers who lack a vocabulary for engaging in close analysis of visual texts may be reluctant to teach them. Recognizing this, teacher educators should equip preservice teachers with a vocabulary for analyzing visual texts. This article…

  3. Improving pattern discovery and visualization of SAGE data through poisson-based self-adaptive neural networks.

    PubMed

    Zheng, Huiru; Wang, Haiying; Azuaje, Francisco

    2008-07-01

    Serial analysis of gene expression (SAGE) allows a detailed, simultaneous analysis of thousands of genes without the need for prior, complete gene sequence information. However, due to its inherent complexity and the lack of complete structural and function knowledge, mining vast collections of SAGE data to extract useful knowledge poses great challenges to traditional analytical techniques. Moreover, SAGE data are characterized by a specific statistical model that has not been incorporated into traditional data analysis techniques. The analysis of SAGE data requires advanced, intelligent computational techniques, which consider the underlying biology and the statistical nature of SAGE data. By addressing the statistical properties demonstrated by SAGE data, this paper presents a new self-adaptive neural network, Poisson-based growing self-organizing map (PGSOM), which implements novel weight adaptation and neuron growing strategies. An empirical study of key dynamic mechanisms of PGSOM is presented. It was tested on three datasets, including synthetic and experimental SAGE data. The results indicate that, in comparison to traditional techniques, the PGSOM offers significant advantages in the context of pattern discovery and visualization in SAGE data. The pattern discovery and visualization platform discussed in this paper can be applied to other problem domains where the data are better approximated by a Poisson distribution.

  4. How does the extent of central visual field loss affect adaptive gait?

    PubMed

    Timmis, Matthew A; Scarfe, Amy C; Pardhan, Shahina

    2016-02-01

    Visual impairment is one of the most important clinical risk factors associated with falls. Currently it remains unclear whether adaptive gait is progressively affected as the extent of central visual field loss (CFL) increases, or when CFL exceeds a certain size. 10 participants (aged 22 ± 3 years) negotiated a floor based obstacle in full vision (no occlusion) and wearing custom made contact lenses which simulated 10° CFL and 20° CFL. Movement kinematics assessed the period immediately prior to and during obstacle crossing. In the 20° CFL condition, participants exhibited adaptations in gait which were consistent with being more cautious and more variable during the approach to and crossing of the obstacle, when compared to both 10° CFL and full vision conditions. Specifically, in the 20° CFL condition participants placed their lead foot further from the obstacle, lifted both their lead and trail feet higher and slower over the obstacle, and took longer to negotiate the obstacle when compared to the 10° CFL and full vision conditions. Data highlights differences in adaptive gait as a function of the extent of CFL when compared to full vision. More importantly, these adaptations were only associated with loss of the central 20° of the visual field, suggesting that gait is compromised only after central visual field loss exceeds a certain level. PMID:27004633

  5. Cross-Cultural Adaptation of a Developmental Assessment for Arabic-Speaking Children with Visual Impairment

    ERIC Educational Resources Information Center

    Macrine, Sheila L.; Heji, Hayat; Sabri, Amel; Dalton, Sara

    2015-01-01

    Developmental screening has become an established component of child health programs in many developed countries. The research objective of this project was to translate and adapt a developmental assessment (Oregon Project Skills Inventory) for use with young children with visual impairments who speak Arabic. The study was prompted by the lack of…

  6. Guidelines for Assessing the Need for Adaptive Devices for Visually Impaired Pedestrians at Signalized Intersections.

    ERIC Educational Resources Information Center

    Gallagher, Brian R.; de Oca, Patricia Montes

    1998-01-01

    Presents guidelines for orientation and mobility instructors and traffic engineers to assess the need for adaptive devices to make crosswalks at signalized intersections accessible to pedestrians with visual impairments. The discussions of audible and tactile pedestrian devices, along with case examples, distinguish when each device should be…

  7. Guidelines for the Practice of Adaptive Diabetes Education for Visually Impaired Persons.

    ERIC Educational Resources Information Center

    Berkowitz, Kathy

    1993-01-01

    This article presents guidelines developed by the American Association of Diabetes Educators concerning adaptive diabetes education for visually impaired persons (ADEVIP). The article discusses definitions, values, and assumptions; recommended professional educational background; role delineation; and process and content of ADEVIP. (DB)

  8. Adaptive luminance contrast for enhancing reading performance and visual comfort on smartphone displays

    NASA Astrophysics Data System (ADS)

    Na, Nooree; Suk, Hyeon-Jeong

    2014-11-01

    This study developed a model for setting the adaptive luminance contrast between text and background for enhancing reading performance and visual comfort on smartphone displays. The study was carried out in two experiments. In Experiment I, a user test was conducted to identify the optimal luminance contrast with regard to subjects' reading performance, measured by lines of text reading and visual comfort, assessed by self-report after the reading. Based on the empirical results of the test, an ideal adaptive model which decreases the luminance contrast gradually with passage of time was developed. In Experiment II, a validation test involving reading performance, visual comfort, and physiological stress measured by a brainwave analysis using an electroencephalogram confirmed that the proposed adaptive luminance contrast is adequate for prolonged text reading on smartphone displays. The developed model enhances both reading performance and visual comfort as well as reduces the energy consumption of a smartphone; hence, it is expected that this study will be applied to diverse kinds of visual display terminals.

  9. Properties of the visual channels that underlie adaptation to gradual change of luminance.

    PubMed

    Arnold, K; Anstis, S

    1993-01-01

    Following adaptation to a spatially uniform patch of light that is gradually brightening (or dimming), a steady test patch appears to be gradually dimming (or brightening). We measured this ramp aftereffect with a nulling method, as a function of the amplitude and temporal repetition rate of the adapting sawtooth waveform and at various retinal eccentricities and levels of dark adaptation. We conclude that the underlying visual channels respond best to large-amplitude sweeps in luminance of at least 20 dB (1 log unit); but they are fairly insensitive to the temporal rate of this sweep. The channels are present out to an eccentricity of at least 40 degrees but they almost disappear during dark adaptation. The ramp aftereffects were asymmetrical: the subjectively darkening aftereffect produced by a brightening adapting ramp was slightly stronger than vice versa.

  10. Preserved implicit form perception and orientation adaptation in visual form agnosia.

    PubMed

    Yang, Jiongjiong; Wu, Ming; Shen, Zheng

    2006-01-01

    Visual form agnosia is mainly characterized by profound deficits in visual form and shape discrimination. Previous studies have shown that patients retain the capacity for coordinated motor behaviors, color naming and implicit letter perception. However, it is unknown to what extent other visual functions, such as implicit form and orientation perception, are preserved. To address these questions, we investigated a single visual form agnosic patient, X.F., in two distinct experiments. X.F.'s visual lesions were mainly localized in the bilateral occipitotemporal cortex, with the dorsal visual stream and early visual cortex largely spared. In Experiment 1, X.F. named the color of different forms across 12 blocks of trials. After the first six blocks, the combinations of a form with its color were changed and the new combination was presented for the remaining six blocks. X.F.'s reaction time increased during the switch block and was significantly greater than the overall RT changes between adjacent, non-switch blocks. This indicates that X.F. retained the ability to perceive changes in form despite her inability to discriminate the forms. In Experiment 2, X.F. showed selective orientation adaptation effects to different spatial frequencies; that is, her contrast threshold was significantly higher when the adapting and test orientations were the same than when they were orthogonal, although her orientation discrimination performance was severely impaired. These data provide evidence of a functional dissociation between explicit and implicit visual abilities, and suggest that the residual early visual cortex mediates form and orientation processing in the absence of awareness.

  11. Visual analytics in healthcare education: exploring novel ways to analyze and represent big data in undergraduate medical education.

    PubMed

    Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

    2014-01-01

    Introduction. The big data present in the medical curriculum that informs undergraduate medical education is beyond human abilities to perceive and analyze. The medical curriculum is the main tool used by teachers and directors to plan, design, and deliver teaching and assessment activities and student evaluations in medical education in a continuous effort to improve it. Big data remains largely unexploited for medical education improvement purposes. The emerging research field of visual analytics has the advantage of combining data analysis and manipulation techniques, information and knowledge representation, and human cognitive strength to perceive and recognize visual patterns. Nevertheless, there is a lack of research on the use and benefits of visual analytics in medical education. Methods. The present study is based on analyzing the data in the medical curriculum of an undergraduate medical program as it concerns teaching activities, assessment methods and learning outcomes in order to explore visual analytics as a tool for finding ways of representing big data from undergraduate medical education for improvement purposes. Cytoscape software was employed to build networks of the identified aspects and visualize them. Results. After the analysis of the curriculum data, eleven aspects were identified. Further analysis and visualization of the identified aspects with Cytoscape resulted in building an abstract model of the examined data that presented three different approaches; (i) learning outcomes and teaching methods, (ii) examination and learning outcomes, and (iii) teaching methods, learning outcomes, examination results, and gap analysis. Discussion. This study identified aspects of medical curriculum that play an important role in how medical education is conducted. The implementation of visual analytics revealed three novel ways of representing big data in the undergraduate medical education context. It appears to be a useful tool to explore such data

  12. Seeing is believing: effects of visual contextual cues on learning and transfer of locomotor adaptation.

    PubMed

    Torres-Oviedo, Gelsy; Bastian, Amy J

    2010-12-15

    Devices such as robots or treadmills are often used to drive motor learning because they can create novel physical environments. However, the learning (i.e., adaptation) acquired on these devices only partially generalizes to natural movements. What determines the specificity of motor learning, and can this be reliably made more general? Here we investigated the effect of visual cues on the specificity of split-belt walking adaptation. We systematically removed vision to eliminate the visual-proprioceptive mismatch that is a salient cue specific to treadmills: vision indicates that we are not moving while leg proprioception indicates that we are. We evaluated the adaptation of temporal and spatial features of gait (i.e., timing and location of foot landing), their transfer to walking over ground, and washout of adaptation when subjects returned to the treadmill. Removing vision during both training (i.e., on the treadmill) and testing (i.e., over ground) strongly improved the transfer of treadmill adaptation to natural walking. Removing vision only during training increased transfer of temporal adaptation, whereas removing vision only during testing increased the transfer of spatial adaptation. This dissociation reveals differences in adaptive mechanisms for temporal and spatial features of walking. Finally training without vision increased the amount that was learned and was linked to the variability in the behavior during adaptation. In conclusion, contextual cues can be manipulated to modulate the magnitude, transfer, and washout of device-induced learning in humans. These results bring us closer to our ultimate goal of developing rehabilitation strategies that improve movements beyond the clinical setting.

  13. Calibration and adaptation of ISO visual noise for I3A's Camera Phone Image Quality initiative

    NASA Astrophysics Data System (ADS)

    Baxter, Donald J.; Murray, Andrew

    2012-01-01

    The I3A Camera Phone Image Quality (CPIQ) visual noise metric described is a core image quality attribute of the wider I3A CPIQ consumer orientated, camera image quality score. This paper describes the selection of a suitable noise metric, the adaptation of the chosen ISO 15739 visual noise protocol for the challenges posed by cell phone cameras and the mapping of the adapted protocol to subjective image quality loss using a published noise study. Via a simple study, visual noise metrics are shown to discriminate between different noise frequency shapes. The optical non-uniformities prevalent in cell phone cameras and higher noise levels pose significant challenges to the ISO 15739 visual noise protocol. The non-uniformities are addressed using a frequency based high pass filter. Secondly, the data clipping at high noise levels is avoided using a Johnson and Fairchild frequency based Luminance contrast sensitivity function (CSF). The final result is a visually based noise metric calibrated in Quality Loss Just Noticeable Differences (JND) using Aptina Imaging's subjectively calibrated image set.

  14. A fully functional rod visual pigment in a blind mammal. A case for adaptive functional reorganization?

    PubMed

    Janssen, J W; Bovee-Geurts, P H; Peeters, Z P; Bowmaker, J K; Cooper, H M; David-Gray, Z K; Nevo, E; DeGrip, W J

    2000-12-01

    In the blind subterranean mole rat Spalax ehrenbergi superspecies complete ablation of the visual image-forming capability has been accompanied by an expansion of the bilateral projection from the retina to the suprachiasmatic nucleus. We have cloned the open reading frame of a visual pigment from Spalax that shows >90% homology with mammalian rod pigments. Baculovirus expression yields a membrane protein with all functional characteristics of a rod visual pigment (lambda(max) = 497 +/- 2 nm; pK(a) of meta I/meta II equilibrium = 6.5; rapid activation of transducin in the light). We not only provide evidence that this Spalax rod pigment is fully functional in vitro but also show that all requirements for a functional pigment are present in vivo. The physiological consequences of this unexpected finding are discussed. One attractive option is that during adaptation to a subterranean lifestyle, the visual system of this mammal has undergone mosaic reorganization, and the visual pigments have adapted to a function in circadian photoreception.

  15. Visual adaptation of the perception of "life": animacy is a basic perceptual dimension of faces.

    PubMed

    Koldewyn, Kami; Hanus, Patricia; Balas, Benjamin

    2014-08-01

    One critical component of understanding another's mind is the perception of "life" in a face. However, little is known about the cognitive and neural mechanisms underlying this perception of animacy. Here, using a visual adaptation paradigm, we ask whether face animacy is (1) a basic dimension of face perception and (2) supported by a common neural mechanism across distinct face categories defined by age and species. Observers rated the perceived animacy of adult human faces before and after adaptation to (1) adult faces, (2) child faces, and (3) dog faces. When testing the perception of animacy in human faces, we found significant adaptation to both adult and child faces, but not dog faces. We did, however, find significant adaptation when morphed dog images and dog adaptors were used. Thus, animacy perception in faces appears to be a basic dimension of face perception that is species specific but not constrained by age categories.

  16. New analytical expressions of the Rossiter-McLaughlin effect adapted to different observation techniques

    NASA Astrophysics Data System (ADS)

    Boué, G.; Montalto, M.; Boisse, I.; Oshagh, M.; Santos, N. C.

    2013-02-01

    The Rossiter-McLaughlin (hereafter RM) effect is a key tool for measuring the projected spin-orbit angle between stellar spin axes and orbits of transiting planets. However, the measured radial velocity (RV) anomalies produced by this effect are not intrinsic and depend on both instrumental resolution and data reduction routines. Using inappropriate formulas to model the RM effect introduces biases, at least in the projected velocity Vsini⋆ compared to the spectroscopic value. Currently, only the iodine cell technique has been modeled, which corresponds to observations done by, e.g., the HIRES spectrograph of the Keck telescope. In this paper, we provide a simple expression of the RM effect specially designed to model observations done by the Gaussian fit of a cross-correlation function (CCF) as in the routines performed by the HARPS team. We derived a new analytical formulation of the RV anomaly associated to the iodine cell technique. For both formulas, we modeled the subplanet mean velocity vp and dispersion βp accurately taking the rotational broadening on the subplanet profile into account. We compare our formulas adapted to the CCF technique with simulated data generated with the numerical software SOAP-T and find good agreement up to Vsini⋆ ≲ 20 km s-1. In contrast, the analytical models simulating the two different observation techniques can disagree by about 10σ in Vsini⋆ for large spin-orbit misalignments. It is thus important to apply the adapted model when fitting data. A public code implementing the expressions derived in this paper is available at http://www.astro.up.pt/resources/arome. A copy of the code is also available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/550/A53

  17. GWAS in a Box: Statistical and Visual Analytics of Structured Associations via GenAMap

    PubMed Central

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

    2014-01-01

    With the continuous improvement in genotyping and molecular phenotyping technology and the decreasing typing cost, it is expected that in a few years, more and more clinical studies of complex diseases will recruit thousands of individuals for pan-omic genetic association analyses. Hence, there is a great need for algorithms and software tools that could scale up to the whole omic level, integrate different omic data, leverage rich structure information, and be easily accessible to non-technical users. We present GenAMap, an interactive analytics software platform that 1) automates the execution of principled machine learning methods that detect genome- and phenome-wide associations among genotypes, gene expression data, and clinical or other macroscopic traits, and 2) provides new visualization tools specifically designed to aid in the exploration of association mapping results. Algorithmically, GenAMap is based on a new paradigm for GWAS and PheWAS analysis, termed structured association mapping, which leverages various structures in the omic data. We demonstrate the function of GenAMap via a case study of the Brem and Kruglyak yeast dataset, and then apply it on a comprehensive eQTL analysis of the NIH heterogeneous stock mice dataset and report some interesting findings. GenAMap is available from http://sailing.cs.cmu.edu/genamap. PMID:24905018

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

    PubMed

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

    2014-01-01

    With the continuous improvement in genotyping and molecular phenotyping technology and the decreasing typing cost, it is expected that in a few years, more and more clinical studies of complex diseases will recruit thousands of individuals for pan-omic genetic association analyses. Hence, there is a great need for algorithms and software tools that could scale up to the whole omic level, integrate different omic data, leverage rich structure information, and be easily accessible to non-technical users. We present GenAMap, an interactive analytics software platform that 1) automates the execution of principled machine learning methods that detect genome- and phenome-wide associations among genotypes, gene expression data, and clinical or other macroscopic traits, and 2) provides new visualization tools specifically designed to aid in the exploration of association mapping results. Algorithmically, GenAMap is based on a new paradigm for GWAS and PheWAS analysis, termed structured association mapping, which leverages various structures in the omic data. We demonstrate the function of GenAMap via a case study of the Brem and Kruglyak yeast dataset, and then apply it on a comprehensive eQTL analysis of the NIH heterogeneous stock mice dataset and report some interesting findings. GenAMap is available from http://sailing.cs.cmu.edu/genamap. PMID:24905018

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

    PubMed

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

    2014-01-01

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

  20. Many-objective optimization and visual analytics reveal key trade-offs for London's water supply

    NASA Astrophysics Data System (ADS)

    Matrosov, Evgenii S.; Huskova, Ivana; Kasprzyk, Joseph R.; Harou, Julien J.; Lambert, Chris; Reed, Patrick M.

    2015-12-01

    In this study, we link a water resource management simulator to multi-objective search to reveal the key trade-offs inherent in planning a real-world water resource system. We consider new supplies and demand management (conservation) options while seeking to elucidate the trade-offs between the best portfolios of schemes to satisfy projected water demands. Alternative system designs are evaluated using performance measures that minimize capital and operating costs and energy use while maximizing resilience, engineering and environmental metrics, subject to supply reliability constraints. Our analysis shows many-objective evolutionary optimization coupled with state-of-the art visual analytics can help planners discover more diverse water supply system designs and better understand their inherent trade-offs. The approach is used to explore future water supply options for the Thames water resource system (including London's water supply). New supply options include a new reservoir, water transfers, artificial recharge, wastewater reuse and brackish groundwater desalination. Demand management options include leakage reduction, compulsory metering and seasonal tariffs. The Thames system's Pareto approximate portfolios cluster into distinct groups of water supply options; for example implementing a pipe refurbishment program leads to higher capital costs but greater reliability. This study highlights that traditional least-cost reliability constrained design of water supply systems masks asset combinations whose benefits only become apparent when more planning objectives are considered.

  1. Multilevel adaptive solution procedure for material nonlinear problems in visual programming environment

    SciTech Connect

    Kim, D.; Ghanem, R.

    1994-12-31

    Multigrid solution technique to solve a material nonlinear problem in a visual programming environment using the finite element method is discussed. The nonlinear equation of equilibrium is linearized to incremental form using Newton-Rapson technique, then multigrid solution technique is used to solve linear equations at each Newton-Rapson step. In the process, adaptive mesh refinement, which is based on the bisection of a pair of triangles, is used to form grid hierarchy for multigrid iteration. The solution process is implemented in a visual programming environment with distributed computing capability, which enables more intuitive understanding of solution process, and more effective use of resources.

  2. PAVA: physiological and anatomical visual analytics for mapping of tissue-specific concentration and time-course data.

    PubMed

    Goldsmith, Michael-Rock; Transue, Thomas R; Chang, Daniel T; Tornero-Velez, Rogelio; Breen, Michael S; Dary, Curtis C

    2010-06-01

    We describe the development and implementation of a Physiological and Anatomical Visual Analytics tool (PAVA), a web browser-based application, used to visualize experimental/simulated chemical time-course data (dosimetry), epidemiological data and Physiologically-Annotated Data (PAD). Using continuous color mapping scheme both spatial (organ shape and location) and temporal (time-course/kinetics) data was cast onto an abstract, layered, 2D visual representation of the human anatomy and physiology. This approach is aligned with the compartment-level of detail afforded by Physiologically-Based Pharmacokinetic (PBPK) modeling of chemical disposition. In this tutorial we provide several illustrative examples of how PAVA may be applied: (1) visualization of multiple organ/tissue simulated dosimetry of a previously published oral exposure route ethanol PBPK model, (2) visualization of PAD such as organ-specific disease time-lines or (3) tissue-specific mRNA expression-level profiles (e.g. phase I/II metabolic enzymes and nuclear receptors) to draw much needed molecular biological conclusions at organ-level resolution conducive to model development. Furthermore, discussion is raised on how graphical representations of PBPK models, and the use of PAVA more generally to visualize PAD, can be of benefit. We believe this novel platform-independent tool for visualizing PAD on physiologically-relevant representations of human anatomy will become a valuable visual analytic addition to the tool-kits of modern exposure scientists, computational biologists, toxicologists, biochemists, molecular biologists, epidemiologists and pathologists alike in visually translating, representing and mining complex PAD relationships required to understand systems biology or manage chemical risk.

  3. Analytical modeling and active vibration suppression of an adaptive circular composite plate with asymmetric constraints

    NASA Astrophysics Data System (ADS)

    Yan, Su; Ghasemi-Nejhad, Mehrdad N.

    2005-05-01

    In this paper, the dynamic analysis of an Adaptive Circular Composite Plate (ACCP) with asymmetric constraints with respect to the angular coordinate system is investigated. Due to the asymmetric constrains, the shape functions of the circular plate could not be simply obtained from the partial differential equation by ignoring the angular dependency. Using the method of separation of variables, the mode shapes are expanded in Bessel series. The comparison of the developed analytical mode shapes with the Finite Element Method (FEM) mode shapes confirmed the validation of the analytical model. A modeling strategy using Rayleigh-Ritz method is presented to build the system model. Taking the effects of piezoelectric actuators on the dynamics of the ACCP into account, the optimal placement of the actuators is investigated. Also, employing the developed model, the simulation of the vibration control is implemented on the ACCP with one central simply support and three edge simply supports using LQR controller. The simulation results verify the best performance of the LQR controller with the optimal configuration for vibration suppression of the ACCP.

  4. Adaptive region of interest method for analytical micro-CT reconstruction.

    PubMed

    Yang, Wanneng; Xu, Xiaochun; Bi, Kun; Zeng, Shaoqun; Liu, Qian; Chen, Shangbin

    2011-01-01

    The real-time imaging is important in automatic successive inspection with micro-computerized tomography (micro-CT). Generally, the size of the detector is chosen according to the most probable size of the measured object to acquire all the projection data. Given enough imaging area and imaging resolution of X-ray detector, the detector is larger than specimen projection area, which results in redundant data in the Sinogram. The process of real-time micro-CT is computation-intensive because of the large amounts of source and destination data. The speed of the reconstruction algorithm can't always meet the requirements of real-time applications. A preprocessing method called adaptive region of interest (AROI), which detects the object's boundaries automatically to focus the active Sinogram regions, is introduced into the analytical reconstruction algorithm in this paper. The AROI method reduces the volume of the reconstructing data and thus directly accelerates the reconstruction process. It has been further shown that image quality is not compromised when applying AROI, while the reconstruction speed is increased as the square of the ratio of the sizes of the detector and the specimen slice. In practice, the conch reconstruction experiment indicated that the process is accelerated by 5.2 times with AROI and the imaging quality is not degraded. Therefore, the AROI method improves the speed of analytical micro-CT reconstruction significantly.

  5. Adaptive region of interest method for analytical micro-CT reconstruction.

    PubMed

    Yang, Wanneng; Xu, Xiaochun; Bi, Kun; Zeng, Shaoqun; Liu, Qian; Chen, Shangbin

    2011-01-01

    The real-time imaging is important in automatic successive inspection with micro-computerized tomography (micro-CT). Generally, the size of the detector is chosen according to the most probable size of the measured object to acquire all the projection data. Given enough imaging area and imaging resolution of X-ray detector, the detector is larger than specimen projection area, which results in redundant data in the Sinogram. The process of real-time micro-CT is computation-intensive because of the large amounts of source and destination data. The speed of the reconstruction algorithm can't always meet the requirements of real-time applications. A preprocessing method called adaptive region of interest (AROI), which detects the object's boundaries automatically to focus the active Sinogram regions, is introduced into the analytical reconstruction algorithm in this paper. The AROI method reduces the volume of the reconstructing data and thus directly accelerates the reconstruction process. It has been further shown that image quality is not compromised when applying AROI, while the reconstruction speed is increased as the square of the ratio of the sizes of the detector and the specimen slice. In practice, the conch reconstruction experiment indicated that the process is accelerated by 5.2 times with AROI and the imaging quality is not degraded. Therefore, the AROI method improves the speed of analytical micro-CT reconstruction significantly. PMID:21422587

  6. Estimating oxygen consumption from heart rate using adaptive neuro-fuzzy inference system and analytical approaches.

    PubMed

    Kolus, Ahmet; Dubé, Philippe-Antoine; Imbeau, Daniel; Labib, Richard; Dubeau, Denise

    2014-11-01

    In new approaches based on adaptive neuro-fuzzy systems (ANFIS) and analytical method, heart rate (HR) measurements were used to estimate oxygen consumption (VO2). Thirty-five participants performed Meyer and Flenghi's step-test (eight of which performed regeneration release work), during which heart rate and oxygen consumption were measured. Two individualized models and a General ANFIS model that does not require individual calibration were developed. Results indicated the superior precision achieved with individualized ANFIS modelling (RMSE = 1.0 and 2.8 ml/kg min in laboratory and field, respectively). The analytical model outperformed the traditional linear calibration and Flex-HR methods with field data. The General ANFIS model's estimates of VO2 were not significantly different from actual field VO2 measurements (RMSE = 3.5 ml/kg min). With its ease of use and low implementation cost, the General ANFIS model shows potential to replace any of the traditional individualized methods for VO2 estimation from HR data collected in the field. PMID:24793823

  7. Visual search disorders in acute and chronic homonymous hemianopia: lesion effects and adaptive strategies.

    PubMed

    Machner, Björn; Sprenger, Andreas; Sander, Thurid; Heide, Wolfgang; Kimmig, Hubert; Helmchen, Christoph; Kömpf, Detlef

    2009-05-01

    Patients with homonymous hemianopia due to occipital brain lesions show disorders of visual search. In everyday life this leads to difficulties in reading and spatial orientation. It is a matter of debate whether these disorders are due to the brain lesion or rather reflect compensatory eye movement strategies developing over time. For the first time, eye movements of acute hemianopic patients (n= 9) were recorded during the first days following stroke while they performed an exploratory visual-search task. Compared to age-matched control subjects their search duration was prolonged due to increased fixations and refixations, that is, repeated scanning of previously searched locations. Saccadic amplitudes were smaller in patients. Right hemianopic patients were more impaired than left hemianopic patients. The number of fixations and refixations did not differ significantly between both hemifields in the patients. Follow-up of one patient revealed changes of visual search over 18 months. By using more structured scanpaths with fewer saccades his search duration decreased. Furthermore, he developed a more efficient eye-movement strategy by making larger but less frequent saccades toward his blind side. In summary, visual-search behavior of acute hemianopic patients differs from healthy control subjects and from chronic hemianopic patients. We conclude that abnormal visual search in acute hemianopic patients is related to the brain lesion. We provide some evidence for adaptive eye-movement strategies developed over time. These adaptive strategies make the visual search more efficient and may help to compensate for the persisting visual-field loss. PMID:19645941

  8. Cross-adaptation combined with TMS reveals a functional overlap between vision and imagery in the early visual cortex.

    PubMed

    Cattaneo, Zaira; Bona, Silvia; Silvanto, Juha

    2012-02-01

    The extent to which the generation of mental images draws on the neuronal representations involved in visual perception has been the subject of much debate. To investigate this overlap, we assessed whether adaptation to visual stimuli affects the ability to generate visual mental images; such cross-adaptation would indicate shared neural representations between visual perception and imagery. Mental imagery was tested using a modified version of the clock task, in which subjects are presented with a digital time (e.g. "2.15") and are asked to generate a mental image of the clock hands displaying this time on an empty clock face. Participants were adapted to oriented lines either on the upper or lower side of the clock face prior to the mental image generation. The results showed that mental imagery was impaired when the mental image had to be generated in the adapted region of visual space (Experiment 1). In Experiment 2, we used TMS to determine whether this adaptation effect occurs in the early visual cortex (EVC; V1/V2). Relative to control conditions (No TMS and Vertex TMS), EVC TMS facilitated mental imagery generation when the mental image spatially overlapped with the adapter. Our results thus show that neuronal representations in the EVC which encode (and are suppressed by) visual input play a causal role in visual mental imagery.

  9. Adaptive methods of two-scale edge detection in post-enhancement visual pattern processing

    NASA Astrophysics Data System (ADS)

    Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

    2008-04-01

    Adaptive methods are defined and experimentally studied for a two-scale edge detection process that mimics human visual perception of edges and is inspired by the parvo-cellular (P) and magno-cellular (M) physiological subsystems of natural vision. This two-channel processing consists of a high spatial acuity/coarse contrast channel (P) and a coarse acuity/fine contrast (M) channel. We perform edge detection after a very strong non-linear image enhancement that uses smart Retinex image processing. Two conditions that arise from this enhancement demand adaptiveness in edge detection. These conditions are the presence of random noise further exacerbated by the enhancement process, and the equally random occurrence of dense textural visual information. We examine how to best deal with both phenomena with an automatic adaptive computation that treats both high noise and dense textures as too much information, and gracefully shifts from a smallscale to medium-scale edge pattern priorities. This shift is accomplished by using different edge-enhancement schemes that correspond with the (P) and (M) channels of the human visual system. We also examine the case of adapting to a third image condition, namely too little visual information, and automatically adjust edge detection sensitivities when sparse feature information is encountered. When this methodology is applied to a sequence of images of the same scene but with varying exposures and lighting conditions, this edge-detection process produces pattern constancy that is very useful for several imaging applications that rely on image classification in variable imaging conditions.

  10. Functional magnetic resonance imaging adaptation reveals a noncategorical representation of hue in early visual cortex.

    PubMed

    Persichetti, Andrew S; Thompson-Schill, Sharon L; Butt, Omar H; Brainard, David H; Aguirre, Geoffrey K

    2015-01-01

    Color names divide the fine-grained gamut of color percepts into discrete categories. A categorical transition must occur somewhere between the initial encoding of the continuous spectrum of light by the cones and the verbal report of the name of a color stimulus. Here, we used a functional magnetic resonance imaging (fMRI) adaptation experiment to examine the representation of hue in the early visual cortex. Our stimuli varied in hue between blue and green. We found in the early visual areas (V1, V2/3, and hV4) a smoothly increasing recovery from adaptation with increasing hue distance between adjacent stimuli during both passive viewing (Experiment 1) and active categorization (Experiment 2). We examined the form of the adaptation effect and found no evidence that a categorical representation mediates the release from adaptation for stimuli that cross the blue-green color boundary. Examination of the direct effect of stimulus hue on the fMRI response did, however, reveal an enhanced response to stimuli near the blue-green category border. This was largest in hV4 and when subjects were engaged in active categorization of the stimulus hue. In contrast with a recent report from another laboratory (Bird, Berens, Horner, & Franklin, 2014), we found no evidence for a categorical representation of color in the middle frontal gyrus. A post hoc whole-brain analysis, however, revealed several regions in the frontal cortex with a categorical effect in the adaptation response. Overall, our results support the idea that the representation of color in the early visual cortex is primarily fine grained and does not reflect color categories. PMID:26024465

  11. TrajGraph: A Graph-Based Visual Analytics Approach to Studying Urban Network Centralities Using Taxi Trajectory Data.

    PubMed

    Huang, Xiaoke; Zhao, Ye; Yang, Jing; Zhang, Chong; Ma, Chao; Ye, Xinyue

    2016-01-01

    We propose TrajGraph, a new visual analytics method, for studying urban mobility patterns by integrating graph modeling and visual analysis with taxi trajectory data. A special graph is created to store and manifest real traffic information recorded by taxi trajectories over city streets. It conveys urban transportation dynamics which can be discovered by applying graph analysis algorithms. To support interactive, multiscale visual analytics, a graph partitioning algorithm is applied to create region-level graphs which have smaller size than the original street-level graph. Graph centralities, including Pagerank and betweenness, are computed to characterize the time-varying importance of different urban regions. The centralities are visualized by three coordinated views including a node-link graph view, a map view and a temporal information view. Users can interactively examine the importance of streets to discover and assess city traffic patterns. We have implemented a fully working prototype of this approach and evaluated it using massive taxi trajectories of Shenzhen, China. TrajGraph's capability in revealing the importance of city streets was evaluated by comparing the calculated centralities with the subjective evaluations from a group of drivers in Shenzhen. Feedback from a domain expert was collected. The effectiveness of the visual interface was evaluated through a formal user study. We also present several examples and a case study to demonstrate the usefulness of TrajGraph in urban transportation analysis.

  12. a Geo-Visual Analytics Approach to Biological Shepherding: Modelling Animal Movements and Impacts

    NASA Astrophysics Data System (ADS)

    Benke, K. K.; Sheth, F.; Betteridge, K.; Pettit, C. J.; Aurambout, J.-P.

    2012-07-01

    The lamb industry in Victoria is a significant component of the state economy with annual exports in the vicinity of 1 billion. GPS and visualisation tools can be used to monitor grazing animal movements at the farm scale and observe interactions with the environment. Modelling the spatial-temporal movements of grazing animals in response to environmental conditions provides input for the design of paddocks with the aim of improving management procedures, animal performance and animal welfare. The term "biological shepherding" is associated with the re-design of environmental conditions and the analysis of responses from grazing animals. The combination of biological shepherding with geo-visual analytics (geo-spatial data analysis with visualisation) provides a framework for improving landscape design and supports research in grazing behaviour in variable landscapes, heat stress avoidance behaviour during summer months, and modelling excreta distributions (with respect to nitrogen emissions and nitrogen return for fertilising the paddock). Nitrogen losses due to excreta are mainly in the form of gaseous emissions to the atmosphere and leaching into the groundwater. In this study, background and context are provided in the case of biological shepherding and tracking animal movements. Examples are provided of recent applications in regional Australia and New Zealand. Based on experimental data and computer simulation, and using data visualisation and feature extraction, it was demonstrated that livestock excreta are not always randomly located, but concentrated around localised gathering points, sometimes separated by the nature of the excretion. Farmers require information on the nitrogen losses in order to reduce emissions to meet local and international nitrogen leaching and greenhouse gas targets and to improve the efficiency of nutrient management.

  13. Web GIS in practice IX: a demonstration of geospatial visual analytics using Microsoft Live Labs Pivot technology and WHO mortality data.

    PubMed

    Kamel Boulos, Maged N; Viangteeravat, Teeradache; Anyanwu, Matthew N; Ra Nagisetty, Venkateswara; Kuscu, Emin

    2011-01-01

    The goal of visual analytics is to facilitate the discourse between the user and the data by providing dynamic displays and versatile visual interaction opportunities with the data that can support analytical reasoning and the exploration of data from multiple user-customisable aspects. This paper introduces geospatial visual analytics, a specialised subtype of visual analytics, and provides pointers to a number of learning resources about the subject, as well as some examples of human health, surveillance, emergency management and epidemiology-related geospatial visual analytics applications and examples of free software tools that readers can experiment with, such as Google Public Data Explorer. The authors also present a practical demonstration of geospatial visual analytics using partial data for 35 countries from a publicly available World Health Organization (WHO) mortality dataset and Microsoft Live Labs Pivot technology, a free, general purpose visual analytics tool that offers a fresh way to visually browse and arrange massive amounts of data and images online and also supports geographic and temporal classifications of datasets featuring geospatial and temporal components. Interested readers can download a Zip archive (included with the manuscript as an additional file) containing all files, modules and library functions used to deploy the WHO mortality data Pivot collection described in this paper.

  14. Effects of retinal position on the visuo-motor adaptation of visual stability in a virtual environment

    PubMed Central

    Kitazaki, Michiteru

    2013-01-01

    Although the retinal image changes a great deal with the movement of our head or eyes, we perceive a stable world (a phenomenon known as visual stability or position constancy). Visual stability adaptively changes for each new combination of vision and head motion, or to compensate for manipulated visuo-motor gain. This study aims to investigate the effects of retinal positions on visuo-motor adaptation and to discuss the neural mechanisms involved. I found that visuo-motor adaptation occurred, and was transferable from right to left visual fields (Experiment 1), between the upper and lower visual fields (Experiment 2), and between the central and peripheral visual fields (Experiment 4), and that for the left visual field (Experiment 1) and the large visual field (Experiment 3) visuo-motor adaptations were effective. The dominance of the central vision was found in Experiment 3 but not found in Experiment 4. These results suggest that the visuo-motor adaptation of visual stability was not specific to the retinal location, but is processed by a relatively high level of the perceptual system. PMID:24349685

  15. Adaptation of the human visual system to the statistics of letters and line configurations.

    PubMed

    Chang, Claire H C; Pallier, Christophe; Wu, Denise H; Nakamura, Kimihiro; Jobert, Antoinette; Kuo, W-J; Dehaene, Stanislas

    2015-10-15

    By adulthood, literate humans have been exposed to millions of visual scenes and pages of text. Does the human visual system become attuned to the statistics of its inputs? Using functional magnetic resonance imaging, we examined whether the brain responses to line configurations are proportional to their natural-scene frequency. To further distinguish prior cortical competence from adaptation induced by learning to read, we manipulated whether the selected configurations formed letters and whether they were presented on the horizontal meridian, the familiar location where words usually appear, or on the vertical meridian. While no natural-scene frequency effect was observed, we observed letter-status and letter frequency effects on bilateral occipital activation, mainly for horizontal stimuli. The findings suggest a reorganization of the visual pathway resulting from reading acquisition under genetic and connectional constraints. Even early retinotopic areas showed a stronger response to letters than to rotated versions of the same shapes, suggesting an early visual tuning to large visual features such as letters. PMID:26190404

  16. Adaptation of visual tracking synchronization after one night of sleep deprivation.

    PubMed

    Tong, Jianliang; Maruta, Jun; Heaton, Kristin J; Maule, Alexis L; Ghajar, Jamshid

    2014-01-01

    The temporal delay between sensory input and motor execution is a fundamental constraint in interactions with the environment. Predicting the temporal course of a stimulus and dynamically synchronizing the required action with the stimulus are critical for offsetting this constraint, and this prediction-synchronization capacity can be tested using visual tracking of a target with predictable motion. Although the role of temporal prediction in visual tracking is assumed, little is known of how internal predictions interact with the behavioral outcome or how changes in the cognitive state influence such interaction. We quantified and compared the predictive visual tracking performance of military volunteers before and after one night of sleep deprivation. The moment-to-moment synchronization of visual tracking during sleep deprivation deteriorated with sensitivity changes greater than 40 %. However, increased anticipatory saccades maintained the overall temporal accuracy with near zero phase error. Results suggest that acute sleep deprivation induces instability in visuomotor prediction, but there is compensatory visuomotor adaptation. Detection of these visual tracking features may aid in the identification of insufficient sleep.

  17. Fitting It All In: Adapting a Green Chemistry Extraction Experiment for Inclusion in an Undergraduate Analytical Laboratory

    ERIC Educational Resources Information Center

    Buckley, Heather L.; Beck, Annelise R.; Mulvihill, Martin J.; Douskey, Michelle C.

    2013-01-01

    Several principles of green chemistry are introduced through this experiment designed for use in the undergraduate analytical chemistry laboratory. An established experiment of liquid CO2 extraction of D-limonene has been adapted to include a quantitative analysis by gas chromatography. This facilitates drop-in incorporation of an exciting…

  18. Analytical, Creative, and Practical Intelligence as Predictors of Self-reported Adaptive Functioning: A Case Study in Russia.

    ERIC Educational Resources Information Center

    Grigorenko, Elena L.; Sternberg, Robert J.

    2001-01-01

    Studied the efficacy of the triarchic theory of intelligence as a basis for predicting adaptive functioning in a rapidly changing society, that of Russia. Results of intelligence measures administered to 452 women and 293 men show that analytical, practical, and creative intelligence all relate in some degree to self-reported everyday adaptive…

  19. Laser-induced Breakdown spectroscopy quantitative analysis method via adaptive analytical line selection and relevance vector machine regression model

    NASA Astrophysics Data System (ADS)

    Yang, Jianhong; Yi, Cancan; Xu, Jinwu; Ma, Xianghong

    2015-05-01

    A new LIBS quantitative analysis method based on analytical line adaptive selection and Relevance Vector Machine (RVM) regression model is proposed. First, a scheme of adaptively selecting analytical line is put forward in order to overcome the drawback of high dependency on a priori knowledge. The candidate analytical lines are automatically selected based on the built-in characteristics of spectral lines, such as spectral intensity, wavelength and width at half height. The analytical lines which will be used as input variables of regression model are determined adaptively according to the samples for both training and testing. Second, an LIBS quantitative analysis method based on RVM is presented. The intensities of analytical lines and the elemental concentrations of certified standard samples are used to train the RVM regression model. The predicted elemental concentration analysis results will be given with a form of confidence interval of probabilistic distribution, which is helpful for evaluating the uncertainness contained in the measured spectra. Chromium concentration analysis experiments of 23 certified standard high-alloy steel samples have been carried out. The multiple correlation coefficient of the prediction was up to 98.85%, and the average relative error of the prediction was 4.01%. The experiment results showed that the proposed LIBS quantitative analysis method achieved better prediction accuracy and better modeling robustness compared with the methods based on partial least squares regression, artificial neural network and standard support vector machine.

  20. Adapting the iSNOBAL model for improved visualization in a GIS environment

    NASA Astrophysics Data System (ADS)

    Johansen, W. J.; Delparte, D.

    2014-12-01

    Snowmelt is a primary means of crucial water resources in much of the western United States. Researchers are developing models that estimate snowmelt to aid in water resource management. One such model is the image snowcover energy and mass balance (iSNOBAL) model. It uses input climate grids to simulate the development and melting of snowpack in mountainous regions. This study looks at applying this model to the Reynolds Creek Experimental Watershed in southwestern Idaho, utilizing novel approaches incorporating geographic information systems (GIS). To improve visualization of the iSNOBAL model, we have adapted it to run in a GIS environment. This type of environment is suited to both the input grid creation and the visualization of results. The data used for input grid creation can be stored locally or on a web-server. Kriging interpolation embedded within Python scripts are used to create air temperature, soil temperature, humidity, and precipitation grids, while built-in GIS and existing tools are used to create solar radiation and wind grids. Additional Python scripting is then used to perform model calculations. The final product is a user-friendly and accessible version of the iSNOBAL model, including the ability to easily visualize and interact with model results, all within a web- or desktop-based GIS environment. This environment allows for interactive manipulation of model parameters and visualization of the resulting input grids for the model calculations. Future work is moving towards adapting the model further for use in a 3D gaming engine for improved visualization and interaction.

  1. Adaptive visual and auditory map alignment in barn owl superior colliculus and its neuromorphic implementation.

    PubMed

    Huo, Juan; Murray, Alan; Wei, Dongqing

    2012-09-01

    Adaptation is one of the most important phenomena in biology. A young barn owl can adapt to imposed environmental changes, such as artificial visual distortion caused by wearing a prism. This adjustment process has been modeled mathematically and the model replicates the sensory map realignment of barn owl superior colliculus (SC) through axonogenesis and synaptogenesis. This allows the biological mechanism to be transferred to an artificial computing system and thereby imbue it with a new form of adaptability to the environment. The model is demonstrated in a real-time robot environment. Results of the experiments are compared with and without prism distortion of vision, and show improved adaptability for the robot. However, the computation speed of the embedded system in the robot is slow. A digital and analog mixed signal very-large-scale integration (VLSI) circuit has been fabricated to implement adaptive sensory pathway changes derived from the SC model at higher speed. VLSI experimental results are consistent with simulation results. PMID:24807931

  2. Autonomous robotic capture of non-cooperative target by adaptive extended Kalman filter based visual servo

    NASA Astrophysics Data System (ADS)

    Dong, Gangqi; Zhu, Zheng H.

    2016-05-01

    This paper presents a real-time, vision-based algorithm for the pose and motion estimation of non-cooperative targets and its application in visual servo robotic manipulator to perform autonomous capture. A hybrid approach of adaptive extended Kalman filter and photogrammetry is developed for the real-time pose and motion estimation of non-cooperative targets. Based on the pose and motion estimates, the desired pose and trajectory of end-effector is defined and the corresponding desired joint angles of the robotic manipulator are derived by inverse kinematics. A close-loop visual servo control scheme is then developed for the robotic manipulator to track, approach and capture the target. Validating experiments are designed and performed on a custom-built six degrees of freedom robotic manipulator with an eye-in-hand configuration. The experimental results demonstrate the feasibility, effectiveness and robustness of the proposed adaptive extended Kalman filter enabled pose and motion estimation and visual servo strategy.

  3. Training improves the capacity of visual working memory when it is adaptive, individualized, and targeted.

    PubMed

    Shin, Eunsam; Lee, Hunjae; Yoo, Sang-Ah; Chong, Sang Chul

    2015-01-01

    The current study investigated whether training improves the capacity of visual working memory using individualized adaptive training methods. Two groups of participants were trained for two targeted processes, filtering and consolidation. Before and after the training, the participants, including those with no training, performed a lateralized change detection task in which one side of the visual display had to be selected and the other side ignored. Across ten-day training sessions, the participants performed two modified versions of the lateralized change detection task. The number of distractors and duration of the consolidation period were adjusted individually to increase the task difficulty of the filtering and consolidation training, respectively. Results showed that the degree of improvement shown during the training was positively correlated with the increase in memory capacity, and training-induced benefits were most evident for larger set sizes in the filtering training group. These results suggest that visual working memory training is effective, especially when it is adaptive, individualized, and targeted.

  4. Filtering Based Adaptive Visual Odometry Sensor Framework Robust to Blurred Images

    PubMed Central

    Zhao, Haiying; Liu, Yong; Xie, Xiaojia; Liao, Yiyi; Liu, Xixi

    2016-01-01

    Visual odometry (VO) estimation from blurred image is a challenging problem in practical robot applications, and the blurred images will severely reduce the estimation accuracy of the VO. In this paper, we address the problem of visual odometry estimation from blurred images, and present an adaptive visual odometry estimation framework robust to blurred images. Our approach employs an objective measure of images, named small image gradient distribution (SIGD), to evaluate the blurring degree of the image, then an adaptive blurred image classification algorithm is proposed to recognize the blurred images, finally we propose an anti-blurred key-frame selection algorithm to enable the VO robust to blurred images. We also carried out varied comparable experiments to evaluate the performance of the VO algorithms with our anti-blur framework under varied blurred images, and the experimental results show that our approach can achieve superior performance comparing to the state-of-the-art methods under the condition with blurred images while not increasing too much computation cost to the original VO algorithms. PMID:27399704

  5. Filtering Based Adaptive Visual Odometry Sensor Framework Robust to Blurred Images.

    PubMed

    Zhao, Haiying; Liu, Yong; Xie, Xiaojia; Liao, Yiyi; Liu, Xixi

    2016-01-01

    Visual odometry (VO) estimation from blurred image is a challenging problem in practical robot applications, and the blurred images will severely reduce the estimation accuracy of the VO. In this paper, we address the problem of visual odometry estimation from blurred images, and present an adaptive visual odometry estimation framework robust to blurred images. Our approach employs an objective measure of images, named small image gradient distribution (SIGD), to evaluate the blurring degree of the image, then an adaptive blurred image classification algorithm is proposed to recognize the blurred images, finally we propose an anti-blurred key-frame selection algorithm to enable the VO robust to blurred images. We also carried out varied comparable experiments to evaluate the performance of the VO algorithms with our anti-blur framework under varied blurred images, and the experimental results show that our approach can achieve superior performance comparing to the state-of-the-art methods under the condition with blurred images while not increasing too much computation cost to the original VO algorithms. PMID:27399704

  6. Filtering Based Adaptive Visual Odometry Sensor Framework Robust to Blurred Images.

    PubMed

    Zhao, Haiying; Liu, Yong; Xie, Xiaojia; Liao, Yiyi; Liu, Xixi

    2016-01-01

    Visual odometry (VO) estimation from blurred image is a challenging problem in practical robot applications, and the blurred images will severely reduce the estimation accuracy of the VO. In this paper, we address the problem of visual odometry estimation from blurred images, and present an adaptive visual odometry estimation framework robust to blurred images. Our approach employs an objective measure of images, named small image gradient distribution (SIGD), to evaluate the blurring degree of the image, then an adaptive blurred image classification algorithm is proposed to recognize the blurred images, finally we propose an anti-blurred key-frame selection algorithm to enable the VO robust to blurred images. We also carried out varied comparable experiments to evaluate the performance of the VO algorithms with our anti-blur framework under varied blurred images, and the experimental results show that our approach can achieve superior performance comparing to the state-of-the-art methods under the condition with blurred images while not increasing too much computation cost to the original VO algorithms.

  7. Multi-source adaptation joint kernel sparse representation for visual classification.

    PubMed

    Tao, JianWen; Hu, Wenjun; Wen, Shiting

    2016-04-01

    Most of the existing domain adaptation learning (DAL) methods relies on a single source domain to learn a classifier with well-generalized performance for the target domain of interest, which may lead to the so-called negative transfer problem. To this end, many multi-source adaptation methods have been proposed. While the advantages of using multi-source domains of information for establishing an adaptation model have been widely recognized, how to boost the robustness of the computational model for multi-source adaptation learning has only recently received attention. To address this issue for achieving enhanced performance, we propose in this paper a novel algorithm called multi-source Adaptation Regularization Joint Kernel Sparse Representation (ARJKSR) for robust visual classification problems. Specifically, ARJKSR jointly represents target dataset by a sparse linear combination of training data of each source domain in some optimal Reproduced Kernel Hilbert Space (RKHS), recovered by simultaneously minimizing the inter-domain distribution discrepancy and maximizing the local consistency, whilst constraining the observations from both target and source domains to share their sparse representations. The optimization problem of ARJKSR can be solved using an efficient alternative direction method. Under the framework ARJKSR, we further learn a robust label prediction matrix for the unlabeled instances of target domain based on the classical graph-based semi-supervised learning (GSSL) diagram, into which multiple Laplacian graphs constructed with the ARJKSR are incorporated. The validity of our method is examined by several visual classification problems. Results demonstrate the superiority of our method in comparison to several state-of-the-arts. PMID:26894961

  8. Visual feedback of the moving arm allows complete adaptation of pointing movements to centrifugal and Coriolis forces in human subjects.

    PubMed

    Bourdin, C; Gauthier, G; Blouin, J; Vercher, J L

    2001-03-23

    A classical visuo-manual adaptation protocol carried out on a rotating platform was used to test the ability of subjects to adapt to centrifugal and Coriolis forces when visual feedback of the arm is manipulated. Three main results emerge: (a) an early modification of the initial trajectory of the movements takes place even without visual feedback of the arm; (b) despite the change in the initial trajectory, the new external force decreases the accuracy of the pointing movements when vision is precluded; (c) a visual adaptive phase allows complete adaptation of the pointing movements performed in a modified gravitoinertial field. Therefore vision would be essential for subjects to completely adapt to centrifugal and Coriolis forces. However, other sensory signals (i.e. vestibular and proprioceptive) may constitute the basis for early but partial correction of the pointing movements.

  9. Big Data Geo-Analytical Tool Development for Spatial Analysis Uncertainty Visualization and Quantification Needs

    NASA Astrophysics Data System (ADS)

    Rose, K.; Bauer, J. R.; Baker, D. V.

    2015-12-01

    As big data computing capabilities are increasingly paired with spatial analytical tools and approaches, there is a need to ensure uncertainty associated with the datasets used in these analyses is adequately incorporated and portrayed in results. Often the products of spatial analyses, big data and otherwise, are developed using discontinuous, sparse, and often point-driven data to represent continuous phenomena. Results from these analyses are generally presented without clear explanations of the uncertainty associated with the interpolated values. The Variable Grid Method (VGM) offers users with a flexible approach designed for application to a variety of analyses where users there is a need to study, evaluate, and analyze spatial trends and patterns while maintaining connection to and communicating the uncertainty in the underlying spatial datasets. The VGM outputs a simultaneous visualization representative of the spatial data analyses and quantification of underlying uncertainties, which can be calculated using data related to sample density, sample variance, interpolation error, uncertainty calculated from multiple simulations. In this presentation we will show how we are utilizing Hadoop to store and perform spatial analysis through the development of custom Spark and MapReduce applications that incorporate ESRI Hadoop libraries. The team will present custom 'Big Data' geospatial applications that run on the Hadoop cluster and integrate with ESRI ArcMap with the team's probabilistic VGM approach. The VGM-Hadoop tool has been specially built as a multi-step MapReduce application running on the Hadoop cluster for the purpose of data reduction. This reduction is accomplished by generating multi-resolution, non-overlapping, attributed topology that is then further processed using ESRI's geostatistical analyst to convey a probabilistic model of a chosen study region. Finally, we will share our approach for implementation of data reduction and topology generation

  10. About turn: the visual representation of human body orientation revealed by adaptation.

    PubMed

    Lawson, Rebecca P; Clifford, Colin W G; Calder, Andrew J

    2009-03-01

    Body orientation provides an important cue to other individuals' focus of attention, particularly when one is viewing them at a distance. Single-cell recording in macaques has identified cells in the superior temporal sulcus that show a view-selective response to particular body orientations. Whether similar separable coding is found in humans is not known, and there is currently no functional account of the visual representation of seen body orientation. This study addressed this issue using visual adaptation. Experiment 1 demonstrated distinct channels that code left- and right-oriented bodies. Experiment 2 investigated whether the visual representation of body orientation is best accounted for by an opponent-coding system, which has been shown to account for the visual representation of facial identity, or by a multichannel system, which provides the optimal account of coding line orientation and direction of motion. Our results provide evidence for multichannel coding of seen body orientation, with separate channels (or neuronal populations) selectively tuned to different body directions.

  11. Visual analytics for finding critical structures in massive time-varying turbulent-flow simulations.

    PubMed

    Gaither, Kelly P; Childs, Hank; Schulz, Karl W; Harrison, Cyrus; Barth, William; Donzis, Diego; Yeung, Pui-Kuen

    2012-01-01

    Visualization and data analysis are crucial in analyzing and understanding a turbulent-flow simulation of size 4,096(3) cells per time slice (68 billion cells) and 17 time slices (one trillion total cells). The visualization techniques used help scientists investigate the dynamics of intense events individually and as these events form clusters.

  12. The research and application of visual saliency and adaptive support vector machine in target tracking field.

    PubMed

    Chen, Yuantao; Xu, Weihong; Kuang, Fangjun; Gao, Shangbing

    2013-01-01

    The efficient target tracking algorithm researches have become current research focus of intelligent robots. The main problems of target tracking process in mobile robot face environmental uncertainty. They are very difficult to estimate the target states, illumination change, target shape changes, complex backgrounds, and other factors and all affect the occlusion in tracking robustness. To further improve the target tracking's accuracy and reliability, we present a novel target tracking algorithm to use visual saliency and adaptive support vector machine (ASVM). Furthermore, the paper's algorithm has been based on the mixture saliency of image features. These features include color, brightness, and sport feature. The execution process used visual saliency features and those common characteristics have been expressed as the target's saliency. Numerous experiments demonstrate the effectiveness and timeliness of the proposed target tracking algorithm in video sequences where the target objects undergo large changes in pose, scale, and illumination. PMID:24363779

  13. Immature visual neural system in children reflected by contrast sensitivity with adaptive optics correction

    PubMed Central

    Liu, Rong; Zhou, Jiawei; Zhao, Haoxin; Dai, Yun; Zhang, Yudong; Tang, Yong; Zhou, Yifeng

    2014-01-01

    This study aimed to explore the neural development status of the visual system of children (around 8 years old) using contrast sensitivity. We achieved this by eliminating the influence of higher order aberrations (HOAs) with adaptive optics correction. We measured HOAs, modulation transfer functions (MTFs) and contrast sensitivity functions (CSFs) of six children and five adults with both corrected and uncorrected HOAs. We found that when HOAs were corrected, children and adults both showed improvements in MTF and CSF. However, the CSF of children was still lower than the adult level, indicating the difference in contrast sensitivity between groups cannot be explained by differences in optical factors. Further study showed that the difference between the groups also could not be explained by differences in non-visual factors. With these results we concluded that the neural systems underlying vision in children of around 8 years old are still immature in contrast sensitivity. PMID:24732728

  14. Image-adapted visually weighted quantization matrices for digital image compression

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B. (Inventor)

    1994-01-01

    A method for performing image compression that eliminates redundant and invisible image components is presented. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

  15. Psychophysical experiments on visual performance with an ocular adaptive optics system - Oral Paper

    NASA Astrophysics Data System (ADS)

    Dalimier, E.; Dainty, J. C.; Barbur, J. L.

    2008-01-01

    An ocular adaptive optics system was used to investigate the effects of higher-order ocular aberrations on everyday functional vision. The system comprised a Shack-Hartmann wavefront sensor, a Badal optometer and cylindrical lenses to statically pre-correct refractive errors, and a 35 element bimorph mirror from AOptix to dynamically compensate for higher-order aberrations. Measurements of contrast acuity with and without correction of higher-order aberrations were performed in a large range of light levels and pupil sizes. The results showed that the visual benefit is limited at all light levels due to the combined effects of light level on pupil size and neural sensitivity.

  16. Multiconjugate adaptive optics for large telescopes: analytical control of the mirror shapes.

    PubMed

    Owner-Petersen, Mette; Goncharov, Alexander

    2002-03-01

    We present an analytical algorithm for deriving the shapes of the deformable mirrors to be used for multiconjugate adaptive correction on a large telescope. The algorithm is optimal in the limit where the overlap of the wave-front contributions from relevant atmospheric layers probed by the guide stars is close to the size of the pupil. The fundamental principle for correction is based on a minimization of the sum of the residual power spectra of the phase fluctuations seen by the guide stars after correction. On the basis of the expressions for the mirror shapes, so-called layer transfer functions describing the distribution of the correction of a single atmospheric layer among the deformable mirrors and the resulting correction of that layer have been derived. It is shown that for five guide stars distributed in a regular cross, two- and three-mirror correction will be possible only up to a maximum frequency defined by the largest separation of the conjugate altitudes of the mirrors and by the angular separation of the guide stars. The performance of the algorithm is investigated in the K band by using a standard seven-layer atmosphere. We present results obtained for two guide-star configurations: a continuous distribution within a given angular radius and a five-star cross pattern with a given angular arm length. The wave-front fluctuations are subjected to correction using one, two, and three deformable mirrors. The needed mirror dynamic range is derived as required root-mean-square stroke and actuator pitch. Finally the performance is estimated in terms of the Strehl ratio obtained by the correction as a function of field angle. No noise has been included in the present analysis, and the guide stars are assumed to be at infinity.

  17. EPIPOI: A user-friendly analytical tool for the extraction and visualization of temporal parameters from epidemiological time series

    PubMed Central

    2012-01-01

    Background There is an increasing need for processing and understanding relevant information generated by the systematic collection of public health data over time. However, the analysis of those time series usually requires advanced modeling techniques, which are not necessarily mastered by staff, technicians and researchers working on public health and epidemiology. Here a user-friendly tool, EPIPOI, is presented that facilitates the exploration and extraction of parameters describing trends, seasonality and anomalies that characterize epidemiological processes. It also enables the inspection of those parameters across geographic regions. Although the visual exploration and extraction of relevant parameters from time series data is crucial in epidemiological research, until now it had been largely restricted to specialists. Methods EPIPOI is freely available software developed in Matlab (The Mathworks Inc) that runs both on PC and Mac computers. Its friendly interface guides users intuitively through useful comparative analyses including the comparison of spatial patterns in temporal parameters. Results EPIPOI is able to handle complex analyses in an accessible way. A prototype has already been used to assist researchers in a variety of contexts from didactic use in public health workshops to the main analytical tool in published research. Conclusions EPIPOI can assist public health officials and students to explore time series data using a broad range of sophisticated analytical and visualization tools. It also provides an analytical environment where even advanced users can benefit by enabling a higher degree of control over model assumptions, such as those associated with detecting disease outbreaks and pandemics. PMID:23153033

  18. Motor adaptation in complex sports - the influence of visual context information on the adaptation of the three-point shot to altered task demands in expert basketball players.

    PubMed

    Stöckel, Tino; Fries, Udo

    2013-01-01

    We examined the influence of visual context information on skilled motor behaviour and motor adaptation in basketball. The rules of basketball in Europe have recently changed, such that that the distance for three-point shots increased from 6.25 m to 6.75 m. As such, we tested the extent to which basketball experts can adapt to the longer distance when a) only the unfamiliar, new three-point line was provided as floor markings (NL group), or b) the familiar, old three-point line was provided in addition to the new floor markings (OL group). In the present study 20 expert basketball players performed 40 three-point shots from 6.25 m and 40 shots from 6.75 m. We assessed the percentage of hits and analysed the landing position of the ball. Results showed better adaptation of throwing performance to the longer distance when the old three-point line was provided as a visual landmark, compared to when only the new three-point line was provided. We hypothesise that the three-point line delivered relevant information needed to successfully adapt to the greater distance in the OL group, whereas it disturbed performance and ability to adapt in the NL group. The importance of visual landmarks on motor adaptation in basketball throwing is discussed relative to the influence of other information sources (i.e. angle of elevation relative to the basket) and sport practice.

  19. Language and Visual Perception Associations: Meta-Analytic Connectivity Modeling of Brodmann Area 37

    PubMed Central

    Rosselli, Monica

    2015-01-01

    Background. Understanding the functions of different brain areas has represented a major endeavor of neurosciences. Historically, brain functions have been associated with specific cortical brain areas; however, modern neuroimaging developments suggest cognitive functions are associated to networks rather than to areas. Objectives. The purpose of this paper was to analyze the connectivity of Brodmann area (BA) 37 (posterior, inferior, and temporal/fusiform gyrus) in relation to (1) language and (2) visual processing. Methods. Two meta-analyses were initially conducted (first level analysis). The first one was intended to assess the language network in which BA37 is involved. The second one was intended to assess the visual perception network. A third meta-analysis (second level analysis) was then performed to assess contrasts and convergence between the two cognitive domains (language and visual perception). The DataBase of Brainmap was used. Results. Our results support the role of BA37 in language but by means of a distinct network from the network that supports its second most important function: visual perception. Conclusion. It was concluded that left BA37 is a common node of two distinct networks—visual recognition (perception) and semantic language functions. PMID:25648869

  20. BiNA: a visual analytics tool for biological network data.

    PubMed

    Gerasch, Andreas; Faber, Daniel; Küntzer, Jan; Niermann, Peter; Kohlbacher, Oliver; Lenhof, Hans-Peter; Kaufmann, Michael

    2014-01-01

    Interactive visual analysis of biological high-throughput data in the context of the underlying networks is an essential task in modern biomedicine with applications ranging from metabolic engineering to personalized medicine. The complexity and heterogeneity of data sets require flexible software architectures for data analysis. Concise and easily readable graphical representation of data and interactive navigation of large data sets are essential in this context. We present BiNA--the Biological Network Analyzer--a flexible open-source software for analyzing and visualizing biological networks. Highly configurable visualization styles for regulatory and metabolic network data offer sophisticated drawings and intuitive navigation and exploration techniques using hierarchical graph concepts. The generic projection and analysis framework provides powerful functionalities for visual analyses of high-throughput omics data in the context of networks, in particular for the differential analysis and the analysis of time series data. A direct interface to an underlying data warehouse provides fast access to a wide range of semantically integrated biological network databases. A plugin system allows simple customization and integration of new analysis algorithms or visual representations. BiNA is available under the 3-clause BSD license at http://bina.unipax.info/.

  1. VAiRoma: A Visual Analytics System for Making Sense of Places, Times, and Events in Roman History.

    PubMed

    Cho, Isaac; Dou, Wewnen; Wang, Derek Xiaoyu; Sauda, Eric; Ribarsky, William

    2016-01-01

    Learning and gaining knowledge of Roman history is an area of interest for students and citizens at large. This is an example of a subject with great sweep (with many interrelated sub-topics over, in this case, a 3,000 year history) that is hard to grasp by any individual and, in its full detail, is not available as a coherent story. In this paper, we propose a visual analytics approach to construct a data driven view of Roman history based on a large collection of Wikipedia articles. Extracting and enabling the discovery of useful knowledge on events, places, times, and their connections from large amounts of textual data has always been a challenging task. To this aim, we introduce VAiRoma, a visual analytics system that couples state-of-the-art text analysis methods with an intuitive visual interface to help users make sense of events, places, times, and more importantly, the relationships between them. VAiRoma goes beyond textual content exploration, as it permits users to compare, make connections, and externalize the findings all within the visual interface. As a result, VAiRoma allows users to learn and create new knowledge regarding Roman history in an informed way. We evaluated VAiRoma with 16 participants through a user study, with the task being to learn about roman piazzas through finding relevant articles and new relationships. Our study results showed that the VAiRoma system enables the participants to find more relevant articles and connections compared to Web searches and literature search conducted in a roman library. Subjective feedback on VAiRoma was also very positive. In addition, we ran two case studies that demonstrate how VAiRoma can be used for deeper analysis, permitting the rapid discovery and analysis of a small number of key documents even when the original collection contains hundreds of thousands of documents.

  2. VAiRoma: A Visual Analytics System for Making Sense of Places, Times, and Events in Roman History.

    PubMed

    Cho, Isaac; Dou, Wewnen; Wang, Derek Xiaoyu; Sauda, Eric; Ribarsky, William

    2016-01-01

    Learning and gaining knowledge of Roman history is an area of interest for students and citizens at large. This is an example of a subject with great sweep (with many interrelated sub-topics over, in this case, a 3,000 year history) that is hard to grasp by any individual and, in its full detail, is not available as a coherent story. In this paper, we propose a visual analytics approach to construct a data driven view of Roman history based on a large collection of Wikipedia articles. Extracting and enabling the discovery of useful knowledge on events, places, times, and their connections from large amounts of textual data has always been a challenging task. To this aim, we introduce VAiRoma, a visual analytics system that couples state-of-the-art text analysis methods with an intuitive visual interface to help users make sense of events, places, times, and more importantly, the relationships between them. VAiRoma goes beyond textual content exploration, as it permits users to compare, make connections, and externalize the findings all within the visual interface. As a result, VAiRoma allows users to learn and create new knowledge regarding Roman history in an informed way. We evaluated VAiRoma with 16 participants through a user study, with the task being to learn about roman piazzas through finding relevant articles and new relationships. Our study results showed that the VAiRoma system enables the participants to find more relevant articles and connections compared to Web searches and literature search conducted in a roman library. Subjective feedback on VAiRoma was also very positive. In addition, we ran two case studies that demonstrate how VAiRoma can be used for deeper analysis, permitting the rapid discovery and analysis of a small number of key documents even when the original collection contains hundreds of thousands of documents. PMID:26529701

  3. Impact of Adaptive Materials on Teachers and their Students with Visual Impairments in Secondary Science and Mathematics Classes

    NASA Astrophysics Data System (ADS)

    Rule, Audrey C.; Stefanich, Greg P.; Boody, Robert M.; Peiffer, Belinda

    2011-04-01

    Science, technology, engineering, and mathematics (STEM) fields, important in today's world, are underrepresented by students with disabilities. Students with visual impairments, although cognitively similar to sighted peers, face challenges as STEM subjects are often taught using visuals. They need alternative forms of access such as enlarged or audio-converted text, tactile graphics, and involvement in hands-on science. This project focused on increasing teacher awareness of and providing funds for the purchase of supplemental adaptive resources, supplies, and equipment. We examined attitude and instructional changes across the year of the programme in 15 science and mathematics teachers educating students with visual impairments. Positive changes were noted from pretest to posttest in student and teacher perspectives, and in teacher attitudes towards students with disabilities in STEM classes. Teachers also provided insights into their challenges and successes through a reflective narrative. Several adolescent students resisted accommodations to avoid appearing conspicuous to peers. Teachers implemented three strategies to address this: providing the adaptations to all students in the class; convincing the student of the need for adaptation; and involving the class in understanding and accepting the student's impairment. A variety of teacher-created adaptations for various science and mathematics labs are reported. Another finding was many adaptations provided for the student with visual impairment benefitted the entire class. This study supports the claim that given knowledgeable, supportive teachers, and with appropriate accommodations such as tactile or auditory materials, students with visual impairments can be as successful and engaged as other students in science and mathematics.

  4. Object tracking using adaptive covariance descriptor and clustering-based model updating for visual surveillance.

    PubMed

    Qin, Lei; Snoussi, Hichem; Abdallah, Fahed

    2014-05-26

    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.

  5. Object Tracking Using Adaptive Covariance Descriptor and Clustering-Based Model Updating for Visual Surveillance

    PubMed Central

    Qin, Lei; Snoussi, Hichem; Abdallah, Fahed

    2014-01-01

    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. PMID:24865883

  6. Quantitative adaptation analytics for assessing dynamic systems of systems: LDRD Final Report

    SciTech Connect

    Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.; Le, Hai D.; Kao, Gio K.; Melander, Darryl J.; Longsine, Dennis Earl; Vander Meer, Jr., Robert C.

    2015-01-01

    Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.

  7. A Visual/Analytical History of the Silent Cinema (1895-1930).

    ERIC Educational Resources Information Center

    Petric, Vladimir

    The proposed project, mentioned in Vladimir Petric's articles "From Written Film History to Visual Film History," is a book intended as a teaching vehicle for college and university film courses and involving shot-by-shot analysis and evaluation of films as primary study material. Cinematic values are emphasized both because cinematic visual…

  8. Visual Input Enhancement and Grammar Learning: A Meta-Analytic Review

    ERIC Educational Resources Information Center

    Lee, Sang-Ki; Huang, Hung-Tzu

    2008-01-01

    Effects of pedagogical interventions with visual input enhancement on grammar learning have been investigated by a number of researchers during the past decade and a half. The present review delineates this research domain via a systematic synthesis of 16 primary studies (comprising 20 unique study samples) retrieved through an exhaustive…

  9. Visual analytics of large multidimensional data using variable binned scatter plots

    NASA Astrophysics Data System (ADS)

    Hao, Ming C.; Dayal, Umeshwar; Sharma, Ratnesh K.; Keim, Daniel A.; Janetzko, Halldór

    2010-01-01

    The scatter plot is a well-known method of visualizing pairs of two-dimensional continuous variables. Multidimensional data can be depicted in a scatter plot matrix. They are intuitive and easy-to-use, but often have a high degree of overlap which may occlude a significant portion of data. In this paper, we propose variable binned scatter plots to allow the visualization of large amounts of data without overlapping. The basic idea is to use a non-uniform (variable) binning of the x and y dimensions and plots all the data points that fall within each bin into corresponding squares. Further, we map a third attribute to color for visualizing clusters. Analysts are able to interact with individual data points for record level information. We have applied these techniques to solve real-world problems on credit card fraud and data center energy consumption to visualize their data distribution and cause-effect among multiple attributes. A comparison of our methods with two recent well-known variants of scatter plots is included.

  10. Flexibility of vestibulo-ocular reflex adaptation to modified visual input in human.

    PubMed

    Watanabe, Shoji; Hattori, Kosuke; Koizuka, Izumi

    2003-02-01

    The vestibulo-ocular reflex (VOR) serves to keep images relatively stable on the retina. To maintain appropriate performance and minimize image slip throughout life, VOR is subjected to long-term adaptive regulation by visual input. It has been reported that adaptive changes in VOR gain (eye velocity/head velocity) are evoked either by fitting subjects with magnifying, miniaturizing, or reversing spectacles during normal behavior, or by moving a large visual field in or out of phase relative to the subject's head movement. The changes in VOR gain are frequency selective. Here, we examine the extent of VOR gain flexibility by causing VORs of similar direction to undergo different behavioral gain changes. Nine healthy adults participated in the study, ranging in age from 24 to 38 years (mean: 26 years) and with no history of neurotological symptoms. All subjects were clinically normal according to a screening battery that included combined neurologic and otologic physical examinations. Horizontal and vertical eye positions were recorded by bitemporal DC-coupled electro-oculography (EOG). The subject sat in a rotating chair. The axis of rotation of the body was always earth-vertical, with the interaural axis crossing the axis of rotation of the chair. The head was pointed 20 degrees downwards in all experiments and stabilized in this position using a chin rest. The chair was surrounded by a half-cylindrical optokinetic screen (78 cm in diameter) placed in front of the subject, onto which random dot patterns were projected. Goggles were used to ensure that the subject was in complete darkness during both pre- and postadaptation periods. The chair was rotated sinusoidally at maximum amplitude of 30 degrees or 60 degrees : for 30 degrees the stimulation was at 0.1, 0.2, 0.3, and 0.4 Hz; for 60 degrees it was at 0.1, 0.2, and 0.3 Hz. VOR adaptation was obtained by inducing a retinal slip velocity by short-term alteration of the visual input of the large field; this change

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Visually induced self-motion sensation adapts rapidly to left-right reversal of vision

    NASA Technical Reports Server (NTRS)

    Oman, C. M.; Bock, O. L.

    1981-01-01

    Three experiments were conducted using 15 adult volunteers with no overt oculomotor or vestibular disorders. In all experiments, left-right vision reversal was achieved using prism goggles, which permitted a binocular field of vision subtending approximately 45 deg horizontally and 28 deg vertically. In all experiments, circularvection (CV) was tested before and immediately after a period of exposure to reversed vision. After one to three hours of active movement while wearing vision-reversing goggles, 10 of 15 (stationary) human subjects viewing a moving stripe display experienced a self-rotation illusion in the same direction as seen stripe motion, rather than in the opposite (normal) direction, demonstrating that the central neural pathways that process visual self-rotation cues can undergo rapid adaptive modification.

  13. Visual analytics for spatial clustering: using a heuristic approach for guided exploration.

    PubMed

    Packer, Eli; Bak, Peter; Nikkilä, Mikko; Polishchuk, Valentin; Ship, Harold J

    2013-12-01

    We propose a novel approach of distance-based spatial clustering and contribute a heuristic computation of input parameters for guiding users in the search of interesting cluster constellations. We thereby combine computational geometry with interactive visualization into one coherent framework. Our approach entails displaying the results of the heuristics to users, as shown in Figure 1, providing a setting from which to start the exploration and data analysis. Addition interaction capabilities are available containing visual feedback for exploring further clustering options and is able to cope with noise in the data. We evaluate, and show the benefits of our approach on a sophisticated artificial dataset and demonstrate its usefulness on real-world data.

  14. Pathways to Identity: Aiding Law Enforcement in Identification Tasks With Visual Analytics

    SciTech Connect

    Bruce, Joseph R.; Scholtz, Jean; Hodges, Duncan; Emanuel, Lia; Stanton-Fraser, Danae; Creese, Sadie; Love, Oriana J.

    2014-09-18

    The nature of identity has changed dramatically in recent years, and has grown in complexity. Identities are defined in multiple domains: biological and psychological elements strongly contribute, but also biographical and cyber elements are necessary to complete the picture. Law enforcement is beginning to adjust to these changes, recognizing its importance in criminal justice. The SuperIdentity project seeks to aid law enforcement officials in their identification tasks through research of techniques for discovering identity traits, generation of statistical models of identity and analysis of identity traits through visualization. We present use cases compiled through user interviews in multiple fields, including law enforcement, as well as the modeling and visualization tools design to aid in those use cases.

  15. [Flexibility in the adaptation of the vestibulo-ocular reflex to modified visual inputs in humans].

    PubMed

    Hattori, K; Watanabe, S; Nakamura, T; Kato, I

    2000-10-01

    The vestibulo-ocular reflex (VOR) serves to stabilize images on the retina. To maintain appropriate performance and minimize image slippage throughout life, the VOR is subject to long-term adaptive regulation in response to visual input. Adaptive changes in VOR gain (eye velocity/head velocity) can be evoked either by fitting subjects with magnifying, miniaturizing, or reversing spectacles during normal behavior or by moving a large visual field in or out of phase relative to the subject's head movement. These changes exhibit frequency-selectivity. Here, we examine the flexibility of VOR gains by causing VOR in similar directions to undergo different behavioral gain changes. Nine healthy adults, ranging in age from 24 to 38 (mean 28.5) with no history of neurotological symptoms participated in the study. All subjects demonstrated clinically normal functioning on a screening battery of tests that included combined neurologic and otologic physical examinations. Horizontal and vertical eye positions were recorded by bitemporal DC coupled electrooculography (EOG). The subject sat in a rotating chair. The axis of rotation of the body was always earth-vertical, the interaural axis crossing the axis of rotation of the chair. The head was positioned at 20 degrees down in all experiments and was stabilized in this position using a chin rest. The chair was 78 cm in diameter and was shielded by a half-cylindrical optokinetic screen positioned in front of the subjects. Random dot patterns were projected onto this screen. During per- and post-adaptation periods, goggles were fitted to ensure that the subject was in complete darkness and the chair was rotated sinusoidally. The amplitude of the rotating chair was 30 degrees and 60 degrees. Frequencies of rotation were 0.1 Hz, 0.2 Hz, 0.3 Hz and 0.4 Hz for amplitudes of 30 degrees and 0.1 Hz, 0.2 Hz, and 0.3 Hz for amplitudes of 60 degrees. To induce VOR adaptation, the retinal slippage velocity caused by the visual input of a

  16. Paradoxical visuomotor adaptation to reversed visual input is predicted by BDNF Val66Met polymorphism

    PubMed Central

    Barton, Brian; Treister, Andrew; Humphrey, Melanie; Abedi, Garen; Cramer, Steven C.; Brewer, Alyssa A.

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) is the most abundant neurotrophin in the brain, influencing neural development, plasticity, and repair (Chen et al., 2004; Thoenen, 1995). The BDNF gene contains a single-nucleotide polymorphism (SNP) called Val66Met. The Met allele interferes with intracellular BDNF-trafficking, decreases activity-dependent BDNF secretion, and consequently is often associated with a shift from plasticity to stability in neural circuits (Egan et al., 2003). We investigated the behavioral consequences of the presence of the Met allele by comparing how 40 heterozygous subjects with the Val/Met genotype and 35 homozygous subjects with the Val/Val genotype performed on visuomotor tasks (reaching and navigation) under two conditions: normal vision and completely left-right reversed vision. As expected, subjects did not differ in their short-term ability to learn the tasks with normal vision (p = 0.58). Intuitively, it would be expected that homozygous Val/Val subjects with a propensity for greater BDNF-induced activity-dependent plasticity would learn new tasks more quickly than heterozygous Val/Met subjects with decreased BDNF secretion (Gilbert, Li, & Piech, 2009). However, we found the opposite here. When short-term mechanisms of visuomotor adaptation were engaged to compensate for the misalignment of visual and somatomotor information created by the left-right reversal of vision, heterozygous Val/Met subjects learned significantly more quickly than their homozygous Val/Val counterparts (p = 0.027). Our results demonstrate the paradoxical finding that the presence of the Met allele, which is thought to promote cortical stability, here improves immediate visuomotor adaptation to left–right-reversed visual input. PMID:25104829

  17. Semantic Enrichment of Movement Behavior with Foursquare--A Visual Analytics Approach.

    PubMed

    Krueger, Robert; Thom, Dennis; Ertl, Thomas

    2015-08-01

    In recent years, many approaches have been developed that efficiently and effectively visualize movement data, e.g., by providing suitable aggregation strategies to reduce visual clutter. Analysts can use them to identify distinct movement patterns, such as trajectories with similar direction, form, length, and speed. However, less effort has been spent on finding the semantics behind movements, i.e. why somebody or something is moving. This can be of great value for different applications, such as product usage and consumer analysis, to better understand urban dynamics, and to improve situational awareness. Unfortunately, semantic information often gets lost when data is recorded. Thus, we suggest to enrich trajectory data with POI information using social media services and show how semantic insights can be gained. Furthermore, we show how to handle semantic uncertainties in time and space, which result from noisy, unprecise, and missing data, by introducing a POI decision model in combination with highly interactive visualizations. Finally, we evaluate our approach with two case studies on a large electric scooter data set and test our model on data with known ground truth. PMID:26357254

  18. An Interactive Visual Analytics Framework for Multi-Field Data in a Geo-Spatial Context

    SciTech Connect

    Zhang, Zhiyuan; Tong, Xiaonan; McDonnell, Kevin T.; Zelenyuk, Alla; Imre, D.; Mueller, Klaus

    2013-04-01

    Climate research produces a wealth of multivariate data. These data often have a geospatial reference and so it is of interest to show them within their geospatial context. One can consider this configuration as a multi field visualization problem, where the geospace provides the expanse of the field. However, there is a limit on the amount of multivariate information that can be fit within a certain spatial location, and the use of linked multivari ate information displays has previously been devised to bridge this gap. In this paper we focus on the interactions in the geographical display, present an implementation that uses Google Earth, and demonstrate it within a tightly linked parallel coordinates display. Several other visual representations, such as pie and bar charts are integrated into the Google Earth display and can be interactively manipulated. Further, we also demonstrate new brushing and visualization techniques for parallel coordinates, such as fixedwindow brushing and correlationenhanced display. We conceived our system with a team of climate researchers, who already made a few important discov eries using it. This demonstrates our system’s great potential to enable scientific discoveries, possibly also in oth er domains where data have a geospatial reference.

  19. Semantic Enrichment of Movement Behavior with Foursquare--A Visual Analytics Approach.

    PubMed

    Krueger, Robert; Thom, Dennis; Ertl, Thomas

    2015-08-01

    In recent years, many approaches have been developed that efficiently and effectively visualize movement data, e.g., by providing suitable aggregation strategies to reduce visual clutter. Analysts can use them to identify distinct movement patterns, such as trajectories with similar direction, form, length, and speed. However, less effort has been spent on finding the semantics behind movements, i.e. why somebody or something is moving. This can be of great value for different applications, such as product usage and consumer analysis, to better understand urban dynamics, and to improve situational awareness. Unfortunately, semantic information often gets lost when data is recorded. Thus, we suggest to enrich trajectory data with POI information using social media services and show how semantic insights can be gained. Furthermore, we show how to handle semantic uncertainties in time and space, which result from noisy, unprecise, and missing data, by introducing a POI decision model in combination with highly interactive visualizations. Finally, we evaluate our approach with two case studies on a large electric scooter data set and test our model on data with known ground truth.

  20. VISAD: an interactive and visual analytical tool for the detection of behavioral anomalies in maritime traffic data

    NASA Astrophysics Data System (ADS)

    Riveiro, Maria; Falkman, Göran; Ziemke, Tom; Warston, Håkan

    2009-05-01

    Monitoring the surveillance of large sea areas normally involves the analysis of huge quantities of heterogeneous data from multiple sources (radars, cameras, automatic identification systems, reports, etc.). The rapid identification of anomalous behavior or any threat activity in the data is an important objective for enabling homeland security. While it is worth acknowledging that many existing mining applications support identification of anomalous behavior, autonomous anomaly detection systems are rarely used in the real world. There are two main reasons: (1) the detection of anomalous behavior is normally not a well-defined and structured problem and therefore, automatic data mining approaches do not work well and (2) the difficulties that these systems have regarding the representation and employment of the prior knowledge that the users bring to their tasks. In order to overcome these limitations, we believe that human involvement in the entire discovery process is crucial. Using a visual analytics process model as a framework, we present VISAD: an interactive, visual knowledge discovery tool for supporting the detection and identification of anomalous behavior in maritime traffic data. VISAD supports the insertion of human expert knowledge in (1) the preparation of the system, (2) the establishment of the normal picture and (3) in the actual detection of rare events. For each of these three modules, VISAD implements different layers of data mining, visualization and interaction techniques. Thus, the detection procedure becomes transparent to the user, which increases his/her confidence and trust in the system and overall, in the whole discovery process.

  1. Visual Tracking Based on the Adaptive Color Attention Tuned Sparse Generative Object Model.

    PubMed

    Tian, Chunna; Gao, Xinbo; Wei, Wei; Zheng, Hong

    2015-12-01

    This paper presents a new visual tracking framework based on an adaptive color attention tuned local sparse model. The histograms of sparse coefficients of all patches in an object are pooled together according to their spatial distribution. A particle filter methodology is used as the location model to predict candidates for object verification during tracking. Since color is an important visual clue to distinguish objects from background, we calculate the color similarity between objects in the previous frames and the candidates in current frame, which is adopted as color attention to tune the local sparse representation-based appearance similarity measurement between the object template and candidates. The color similarity can be calculated efficiently with hash coded color names, which helps the tracker find more reliable objects during tracking. We use a flexible local sparse coding of the object to evaluate the degeneration degree of the appearance model, based on which we build a model updating mechanism to alleviate drifting caused by temporal varying multi-factors. Experiments on 76 challenging benchmark color sequences and the evaluation under the object tracking benchmark protocol demonstrate the superiority of the proposed tracker over the state-of-the-art methods in accuracy. PMID:26390460

  2. AdaptiviTree: adaptive tree visualization for tournament-style brackets.

    PubMed

    Tan, Desney; Smith, Greg; Lee, Bongshin; Robertson, George

    2007-01-01

    Online pick'em games, such as the recent NCAA college basketball March Madness tournament, form a large and rapidly growing industry. In these games, players make predictions on a tournament bracket that defines which competitors play each other and how they proceed toward a single champion. Throughout the course of the tournament, players monitor the brackets to track progress and to compare predictions made by multiple players. This is often a complex sensemaking task. The classic bracket visualization was designed for use on paper and utilizes an incrementally additive system in which the winner of each match-up is rewritten in the next round as the tournament progresses. Unfortunately, this representation requires a significant amount of space and makes it relatively difficult to get a quick overview of the tournament state since competitors take arbitrary paths through the static bracket. In this paper, we present AdaptiviTree, a novel visualization that adaptively deforms the representation of the tree and uses its shape to convey outcome information. AdaptiviTree not only provides a more compact and understandable representation, but also allows overlays that display predictions as well as other statistics. We describe results from a lab study we conducted to explore the efficacy of AdaptiviTree, as well as from a deployment of the system in a recent real-world sports tournament.

  3. Melanopsin-Derived Visual Responses under Light Adapted Conditions in the Mouse dLGN

    PubMed Central

    Davis, Katherine E.; Eleftheriou, Cyril G.; Allen, Annette E.; Procyk, Christopher A.; Lucas, Robert J.

    2015-01-01

    A direct projection from melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) reaches the primary visual thalamus (dorsal lateral geniculate nucleus; dLGN). The significance of this melanopsin input to the visual system is only recently being investigated. One unresolved question is the degree to which neurons in the dLGN could use melanopsin to track dynamic changes in light intensity under light adapted conditions. Here we set out to address this question. We were able to present full field steps visible only to melanopsin by switching between rod-isoluminant ‘yellow’ and ‘blue’ lights in a mouse lacking cone function (Cnga3-/-). In the retina these stimuli elicited melanopsin-like responses from a subset of ganglion cells. When presented to anaesthetised mice, we found that ~25-30% of visually responsive neurones in the contralateral dLGN responded to these melanopsin-isolating steps with small increases in firing rate. Such responses could be elicited even with fairly modest increases in effective irradiance (32% Michelson contrast for melanopsin). These melanopsin-driven responses were apparent at bright backgrounds (corresponding to twilight-daylight conditions), but their threshold irradiance was strongly dependent upon prior light exposure when stimuli were superimposed on a spectrally neutral ramping background light. While both onset and offset latencies were long for melanopsin-derived responses compared to those evoked by rods, there was great variability in these parameters with some cells responding to melanopsin steps in <1 s. These data indicate that a subset of dLGN units can employ melanopsin signals to detect modest changes in irradiance under photopic conditions. PMID:25822371

  4. Level-by-level artificial viscosity and visualization for MHD simulation with adaptive mesh refinement

    NASA Astrophysics Data System (ADS)

    Hatori, Tomoharu; Ito, Atsushi M.; Nunami, Masanori; Usui, Hideyuki; Miura, Hideaki

    2016-08-01

    We propose a numerical method to determine the artificial viscosity in magnetohydrodynamics (MHD) simulations with adaptive mesh refinement (AMR) method, where the artificial viscosity is adaptively changed due to the resolution level of the AMR hierarchy. Although the suitable value of the artificial viscosity depends on the governing equations and the model of target problem, it can be determined by von Neumann stability analysis. By means of the new method, "level-by-level artificial viscosity method," MHD simulations of Rayleigh-Taylor instability (RTI) are carried out with the AMR method. The validity of the level-by-level artificial viscosity method is confirmed by the comparison of the linear growth rates of RTI between the AMR simulations and the simple simulations with uniform grid and uniform artificial viscosity whose resolution is the same as that in the highest level of the AMR simulation. Moreover, in the nonlinear phase of RTI, the secondary instability is clearly observed where the hierarchical data structure of AMR calculation is visualized as high resolution region floats up like terraced fields. In the applications of the method to general fluid simulations, the growth of small structures can be sufficiently reproduced, while the divergence of numerical solutions can be suppressed.

  5. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

    PubMed Central

    Khan, Omar Usman

    2016-01-01

    Short Time Fourier Transform (STFT) is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT) to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT). Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

  6. Query-Adaptive Hash Code Ranking for Large-Scale Multi-View Visual Search.

    PubMed

    Liu, Xianglong; Huang, Lei; Deng, Cheng; Lang, Bo; Tao, Dacheng

    2016-10-01

    Hash-based nearest neighbor search has become attractive in many applications. However, the quantization in hashing usually degenerates the discriminative power when using Hamming distance ranking. Besides, for large-scale visual search, existing hashing methods cannot directly support the efficient search over the data with multiple sources, and while the literature has shown that adaptively incorporating complementary information from diverse sources or views can significantly boost the search performance. To address the problems, this paper proposes a novel and generic approach to building multiple hash tables with multiple views and generating fine-grained ranking results at bitwise and tablewise levels. For each hash table, a query-adaptive bitwise weighting is introduced to alleviate the quantization loss by simultaneously exploiting the quality of hash functions and their complement for nearest neighbor search. From the tablewise aspect, multiple hash tables are built for different data views as a joint index, over which a query-specific rank fusion is proposed to rerank all results from the bitwise ranking by diffusing in a graph. Comprehensive experiments on image search over three well-known benchmarks show that the proposed method achieves up to 17.11% and 20.28% performance gains on single and multiple table search over the state-of-the-art methods. PMID:27448359

  7. Query-Adaptive Hash Code Ranking for Large-Scale Multi-View Visual Search.

    PubMed

    Liu, Xianglong; Huang, Lei; Deng, Cheng; Lang, Bo; Tao, Dacheng

    2016-10-01

    Hash-based nearest neighbor search has become attractive in many applications. However, the quantization in hashing usually degenerates the discriminative power when using Hamming distance ranking. Besides, for large-scale visual search, existing hashing methods cannot directly support the efficient search over the data with multiple sources, and while the literature has shown that adaptively incorporating complementary information from diverse sources or views can significantly boost the search performance. To address the problems, this paper proposes a novel and generic approach to building multiple hash tables with multiple views and generating fine-grained ranking results at bitwise and tablewise levels. For each hash table, a query-adaptive bitwise weighting is introduced to alleviate the quantization loss by simultaneously exploiting the quality of hash functions and their complement for nearest neighbor search. From the tablewise aspect, multiple hash tables are built for different data views as a joint index, over which a query-specific rank fusion is proposed to rerank all results from the bitwise ranking by diffusing in a graph. Comprehensive experiments on image search over three well-known benchmarks show that the proposed method achieves up to 17.11% and 20.28% performance gains on single and multiple table search over the state-of-the-art methods.

  8. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization.

    PubMed

    Nisar, Shibli; Khan, Omar Usman; Tariq, Muhammad

    2016-01-01

    Short Time Fourier Transform (STFT) is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT) to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT). Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection. PMID:27642291

  9. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

    PubMed Central

    Khan, Omar Usman

    2016-01-01

    Short Time Fourier Transform (STFT) is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT) to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT). Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection. PMID:27642291

  10. Analytical expression of long-exposure adaptive-optics-corrected coronagraphic image. First application to exoplanet detection.

    PubMed

    Sauvage, J-F; Mugnier, L M; Rousset, G; Fusco, T

    2010-11-01

    In this paper we derive an analytical model of a long-exposure star image for an adaptive-optics(AO)-corrected coronagraphic imaging system. This expression accounts for static aberrations upstream and downstream of the coronagraphic mask as well as turbulence residuals. It is based on the perfect coronagraph model. The analytical model is validated by means of simulations using the design and parameters of the SPHERE instrument. The analytical model is also compared to a simulated four-quadrant phase-mask coronagraph. Then, its sensitivity to a miscalibration of structure function and upstream static aberrations is studied, and the impact on exoplanet detectability is quantified. Last, a first inversion method is presented for a simulation case using a single monochromatic image with no reference. The obtained result shows a planet detectability increase by two orders of magnitude with respect to the raw image. This analytical model presents numerous potential applications in coronographic imaging, such as exoplanet direct detection, and circumstellar disk observation.

  11. Analytical expression of long-exposure adaptive-optics-corrected coronagraphic image. First application to exoplanet detection.

    PubMed

    Sauvage, J-F; Mugnier, L M; Rousset, G; Fusco, T

    2010-11-01

    In this paper we derive an analytical model of a long-exposure star image for an adaptive-optics(AO)-corrected coronagraphic imaging system. This expression accounts for static aberrations upstream and downstream of the coronagraphic mask as well as turbulence residuals. It is based on the perfect coronagraph model. The analytical model is validated by means of simulations using the design and parameters of the SPHERE instrument. The analytical model is also compared to a simulated four-quadrant phase-mask coronagraph. Then, its sensitivity to a miscalibration of structure function and upstream static aberrations is studied, and the impact on exoplanet detectability is quantified. Last, a first inversion method is presented for a simulation case using a single monochromatic image with no reference. The obtained result shows a planet detectability increase by two orders of magnitude with respect to the raw image. This analytical model presents numerous potential applications in coronographic imaging, such as exoplanet direct detection, and circumstellar disk observation. PMID:21045877

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

    SciTech Connect

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

    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.

  13. An Example of a Hakomi Technique Adapted for Functional Analytic Psychotherapy

    ERIC Educational Resources Information Center

    Collis, Peter

    2012-01-01

    Functional Analytic Psychotherapy (FAP) is a model of therapy that lends itself to integration with other therapy models. This paper aims to provide an example to assist others in assimilating techniques from other forms of therapy into FAP. A technique from the Hakomi Method is outlined and modified for FAP. As, on the whole, psychotherapy…

  14. Development and Adaptation of an Employment-Integration Program for People Who Are Visually Impaired in Quebec, Canada

    ERIC Educational Resources Information Center

    Wittich, Walter; Watanabe, Donald H.; Scully, Lizabeth; Bergevin , Martin

    2013-01-01

    Introduction: In the Province of Quebec, Canada, it is estimated that only about one-third of working-age adults with visual impairments are part of the workforce, despite ongoing efforts of rehabilitation and government agencies to integrate these individuals. The present article describes the development and adaptation of a pre-employment…

  15. An interactive web-based system using cloud for large-scale visual analytics

    NASA Astrophysics Data System (ADS)

    Kaseb, Ahmed S.; Berry, Everett; Rozolis, Erik; McNulty, Kyle; Bontrager, Seth; Koh, Youngsol; Lu, Yung-Hsiang; Delp, Edward J.

    2015-03-01

    Network cameras have been growing rapidly in recent years. Thousands of public network cameras provide tremendous amount of visual information about the environment. There is a need to analyze this valuable information for a better understanding of the world around us. This paper presents an interactive web-based system that enables users to execute image analysis and computer vision techniques on a large scale to analyze the data from more than 65,000 worldwide cameras. This paper focuses on how to use both the system's website and Application Programming Interface (API). Given a computer program that analyzes a single frame, the user needs to make only slight changes to the existing program and choose the cameras to analyze. The system handles the heterogeneity of the geographically distributed cameras, e.g. different brands, resolutions. The system allocates and manages Amazon EC2 and Windows Azure cloud resources to meet the analysis requirements.

  16. Visual Analytics for Comparison of Ocean Model Output with Reference Data: Detecting and Analyzing Geophysical Processes Using Clustering Ensembles.

    PubMed

    Köthur, Patrick; Sips, Mike; Dobslaw, Henryk; Dransch, Doris

    2014-12-01

    Researchers assess the quality of an ocean model by comparing its output to that of a previous model version or to observations. One objective of the comparison is to detect and to analyze differences and similarities between both data sets regarding geophysical processes, such as particular ocean currents. This task involves the analysis of thousands or hundreds of thousands of geographically referenced temporal profiles in the data. To cope with the amount of data, modelers combine aggregation of temporal profiles to single statistical values with visual comparison. Although this strategy is based on experience and a well-grounded body of expert knowledge, our discussions with domain experts have shown that it has two limitations: (1) using a single statistical measure results in a rather limited scope of the comparison and in significant loss of information, and (2) the decisions modelers have to make in the process may lead to important aspects being overlooked. In this article, we propose a Visual Analytics approach that broadens the scope of the analysis, reduces subjectivity, and facilitates comparison of the two data sets. It comprises three steps: First, it allows modelers to consider many aspects of the temporal behavior of geophysical processes by conducting multiple clusterings of the temporal profiles in each data set. Modelers can choose different features describing the temporal behavior of relevant processes, clustering algorithms, and parameterizations. Second, our approach consolidates the clusterings of one data set into a single clustering via a clustering ensembles approach. The consolidated clustering presents an overview of the geospatial distribution of temporal behavior in a data set. Third, a visual interface allows modelers to compare the two consolidated clusterings. It enables them to detect clusters of temporal profiles that represent geophysical processes and to analyze differences and similarities between two data sets. This work is

  17. Visual Analytics for Comparison of Ocean Model Output with Reference Data: Detecting and Analyzing Geophysical Processes Using Clustering Ensembles.

    PubMed

    Köthur, Patrick; Sips, Mike; Dobslaw, Henryk; Dransch, Doris

    2014-12-01

    Researchers assess the quality of an ocean model by comparing its output to that of a previous model version or to observations. One objective of the comparison is to detect and to analyze differences and similarities between both data sets regarding geophysical processes, such as particular ocean currents. This task involves the analysis of thousands or hundreds of thousands of geographically referenced temporal profiles in the data. To cope with the amount of data, modelers combine aggregation of temporal profiles to single statistical values with visual comparison. Although this strategy is based on experience and a well-grounded body of expert knowledge, our discussions with domain experts have shown that it has two limitations: (1) using a single statistical measure results in a rather limited scope of the comparison and in significant loss of information, and (2) the decisions modelers have to make in the process may lead to important aspects being overlooked. In this article, we propose a Visual Analytics approach that broadens the scope of the analysis, reduces subjectivity, and facilitates comparison of the two data sets. It comprises three steps: First, it allows modelers to consider many aspects of the temporal behavior of geophysical processes by conducting multiple clusterings of the temporal profiles in each data set. Modelers can choose different features describing the temporal behavior of relevant processes, clustering algorithms, and parameterizations. Second, our approach consolidates the clusterings of one data set into a single clustering via a clustering ensembles approach. The consolidated clustering presents an overview of the geospatial distribution of temporal behavior in a data set. Third, a visual interface allows modelers to compare the two consolidated clusterings. It enables them to detect clusters of temporal profiles that represent geophysical processes and to analyze differences and similarities between two data sets. This work is

  18. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    PubMed

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported. PMID:26661473

  19. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    PubMed

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported.

  20. MALINA: a web service for visual analytics of human gut microbiota whole-genome metagenomic reads.

    PubMed

    Tyakht, Alexander V; Popenko, Anna S; Belenikin, Maxim S; Altukhov, Ilya A; Pavlenko, Alexander V; Kostryukova, Elena S; Selezneva, Oksana V; Larin, Andrei K; Karpova, Irina Y; Alexeev, Dmitry G

    2012-01-01

    MALINA is a web service for bioinformatic analysis of whole-genome metagenomic data obtained from human gut microbiota sequencing. As input data, it accepts metagenomic reads of various sequencing technologies, including long reads (such as Sanger and 454 sequencing) and next-generation (including SOLiD and Illumina). It is the first metagenomic web service that is capable of processing SOLiD color-space reads, to authors' knowledge. The web service allows phylogenetic and functional profiling of metagenomic samples using coverage depth resulting from the alignment of the reads to the catalogue of reference sequences which are built into the pipeline and contain prevalent microbial genomes and genes of human gut microbiota. The obtained metagenomic composition vectors are processed by the statistical analysis and visualization module containing methods for clustering, dimension reduction and group comparison. Additionally, the MALINA database includes vectors of bacterial and functional composition for human gut microbiota samples from a large number of existing studies allowing their comparative analysis together with user samples, namely datasets from Russian Metagenome project, MetaHIT and Human Microbiome Project (downloaded from http://hmpdacc.org). MALINA is made freely available on the web at http://malina.metagenome.ru. The website is implemented in JavaScript (using Ext JS), Microsoft .NET Framework, MS SQL, Python, with all major browsers supported.

  1. Novel Visual and Analytical Methods in Repurposing Legacy Scientific Code - A Case Study

    SciTech Connect

    Oehmen, Christopher S.; Curtis, Darren S.; Phillips, Aaron R.; Peterson, Elena S.

    2013-07-23

    Scientific computing is dominated by team-authored legacy code that has evolved over decades with the purpose of capturing the evolving understanding of a scientific discipline. Accumulated deprecated code, various optimization techniques, and evolving algorithms lead to convoluted source code that is impractical to reverse engineer using mainstream methods. This prevents codes from being truly repeatable or understandable, which are two of the most essential needs in scientific computing. We refactored a long-standing implementation of a common biosequence alignment algorithm in an effort to reproduce its salient behaviors in usable form. Because of the sheer size and complexity of this code base, we developed custom tools to visualize and manipulate the source code behavior under a variety of conditions. We present a case study of extracting and refactoring the algorithmic core and a novel process of discovery/prototyping/testing using a combination of openly available and custom-built tools. The result is a reduction in code size of over 2 orders of magnitude while reconstructing the key protein alignment function in BLAST

  2. Temperature dependence of dark-adapted sensitivity and light-adaptation in photoreceptors with A1 visual pigments: a comparison of frog L-cones and rods.

    PubMed

    Heikkinen, H; Nymark, S; Donner, K; Koskelainen, A

    2009-07-01

    Flash responses of L-cones and rods were recorded as ERG mass potentials in the frog retina at different temperatures (2-25 degrees C). The purpose was to elucidate factors that make cones faster and less sensitive than rods, particularly the possible role of thermal activation of L-cone visual pigment in maintaining a "light-adapted" state even in darkness. Up to ca. 15 degrees C, cones and rods were desensitized roughly equally by warming (Q(10) approximately 2.2-2.7), retaining a 5-fold sensitivity difference. In this range, the cone/rod difference must depend on factors other than thermal activation of the visual pigment. Above 15 degrees C, cones showed an additional component of desensitization compared with rods, coupled to accelerated response shut-off. This behavior is consistent with light-adaptation from temperature-dependent intrinsic activity (dark light). The apparent dark light as measured by the minimum background intensities needed to affect sensitivity and/or kinetics increased by ca. 10-fold between 15 and 25 degrees C, whereas reported increases in visual-pigment activation rates over this range are less than 5-fold. We conclude that the dark state of frog L-cones above 15 degrees C may be largely set by thermal activation of the phototransduction machinery, but only part of the experimentally determined dark light can be ascribed to the visual pigment.

  3. A New-Fangled FES-k-Means Clustering Algorithm for Disease Discovery and Visual Analytics.

    PubMed

    Oyana, Tonny J

    2010-01-01

    The central purpose of this study is to further evaluate the quality of the performance of a new algorithm. The study provides additional evidence on this algorithm that was designed to increase the overall efficiency of the original k-means clustering technique-the Fast, Efficient, and Scalable k-means algorithm (FES-k-means). The FES-k-means algorithm uses a hybrid approach that comprises the k-d tree data structure that enhances the nearest neighbor query, the original k-means algorithm, and an adaptation rate proposed by Mashor. This algorithm was tested using two real datasets and one synthetic dataset. It was employed twice on all three datasets: once on data trained by the innovative MIL-SOM method and then on the actual untrained data in order to evaluate its competence. This two-step approach of data training prior to clustering provides a solid foundation for knowledge discovery and data mining, otherwise unclaimed by clustering methods alone. The benefits of this method are that it produces clusters similar to the original k-means method at a much faster rate as shown by runtime comparison data; and it provides efficient analysis of large geospatial data with implications for disease mechanism discovery. From a disease mechanism discovery perspective, it is hypothesized that the linear-like pattern of elevated blood lead levels discovered in the city of Chicago may be spatially linked to the city's water service lines.

  4. Predictive analytics of environmental adaptability in multi-omic network models.

    PubMed

    Angione, Claudio; Lió, Pietro

    2015-01-01

    Bacterial phenotypic traits and lifestyles in response to diverse environmental conditions depend on changes in the internal molecular environment. However, predicting bacterial adaptability is still difficult outside of laboratory controlled conditions. Many molecular levels can contribute to the adaptation to a changing environment: pathway structure, codon usage, metabolism. To measure adaptability to changing environmental conditions and over time, we develop a multi-omic model of Escherichia coli that accounts for metabolism, gene expression and codon usage at both transcription and translation levels. After the integration of multiple omics into the model, we propose a multiobjective optimization algorithm to find the allowable and optimal metabolic phenotypes through concurrent maximization or minimization of multiple metabolic markers. In the condition space, we propose Pareto hypervolume and spectral analysis as estimators of short term multi-omic (transcriptomic and metabolic) evolution, thus enabling comparative analysis of metabolic conditions. We therefore compare, evaluate and cluster different experimental conditions, models and bacterial strains according to their metabolic response in a multidimensional objective space, rather than in the original space of microarray data. We finally validate our methods on a phenomics dataset of growth conditions. Our framework, named METRADE, is freely available as a MATLAB toolbox.

  5. Predictive analytics of environmental adaptability in multi-omic network models

    PubMed Central

    Angione, Claudio; Lió, Pietro

    2015-01-01

    Bacterial phenotypic traits and lifestyles in response to diverse environmental conditions depend on changes in the internal molecular environment. However, predicting bacterial adaptability is still difficult outside of laboratory controlled conditions. Many molecular levels can contribute to the adaptation to a changing environment: pathway structure, codon usage, metabolism. To measure adaptability to changing environmental conditions and over time, we develop a multi-omic model of Escherichia coli that accounts for metabolism, gene expression and codon usage at both transcription and translation levels. After the integration of multiple omics into the model, we propose a multiobjective optimization algorithm to find the allowable and optimal metabolic phenotypes through concurrent maximization or minimization of multiple metabolic markers. In the condition space, we propose Pareto hypervolume and spectral analysis as estimators of short term multi-omic (transcriptomic and metabolic) evolution, thus enabling comparative analysis of metabolic conditions. We therefore compare, evaluate and cluster different experimental conditions, models and bacterial strains according to their metabolic response in a multidimensional objective space, rather than in the original space of microarray data. We finally validate our methods on a phenomics dataset of growth conditions. Our framework, named METRADE, is freely available as a MATLAB toolbox. PMID:26482106

  6. An improved human visual system based reversible data hiding method using adaptive histogram modification

    NASA Astrophysics Data System (ADS)

    Hong, Wien; Chen, Tung-Shou; Wu, Mei-Chen

    2013-03-01

    Jung et al., IEEE Signal Processing Letters, 18, 2, 95, 2011 proposed a reversible data hiding method considering the human visual system (HVS). They employed the mean of visited neighboring pixels to predict the current pixel value, and estimated the just noticeable difference (JND) of the current pixel. Message bits are then embedded by adjusting the embedding level according to the calculated JND. Jung et al.'s method achieved excellent image quality. However, the embedding algorithm they used may result in over modification of pixel values and a large location map, which may deteriorate the image quality and decrease the pure payload. The proposed method exploits the nearest neighboring pixels to predict the visited pixel value and to estimate the corresponding JND. The cover pixels are preprocessed adaptively to reduce the size of the location map. We also employ an embedding level selection mechanism to prevent near-saturated pixels from being over modified. Experimental results show that the image quality of the proposed method is higher than that of Jung et al.'s method, and the payload can also be increased due to the reduction of the location map.

  7. Efficacy of visual-scanning training and prism adaptation for neglect rehabilitation.

    PubMed

    Spaccavento, Simona; Cellamare, Fara; Cafforio, Elisabetta; Loverre, Anna; Craca, Angela

    2016-01-01

    Unilateral spatial neglect consists of the inability of a patient to respond, orient, and attend to stimuli on the left side of a space following a right-hemisphere lesion. Many rehabilitation approaches have been proposed to reduce neglect. The aim of our study was to compare the effect of visual-scanning training (VST) and prismatic adaptation (PA) on patients with neglect following a right-hemisphere lesion. Twenty patients with left neglect were enrolled in the study. Before and after training, a comprehensive neuropsychological assessment of visuospatial abilities, evaluating personal, peripersonal, and extrapersonal neglect, was performed. After assessment, patients were alternately assigned to 1 of 2 groups, VST or PA. Both trainings consisted of 20 sessions, 1 per day, 5 days a week for 4 weeks. The results showed that both treatments improved patient neglect, especially in personal and peripersonal spaces. No difference between pretreatment and posttreatment was found in extrapersonal subscales. This finding could be due to the fact that there were no exercises requiring the use of objects within reach in either training. In conclusion, no difference between the 2 approaches was found, and both are useful rehabilitation techniques that appear to improve neglect.

  8. CONCH: A Visual Basic program for interactive processing of ion-microprobe analytical data

    NASA Astrophysics Data System (ADS)

    Nelson, David R.

    2006-11-01

    A Visual Basic program for flexible, interactive processing of ion-microprobe data acquired for quantitative trace element, 26Al- 26Mg, 53Mn- 53Cr, 60Fe- 60Ni and U-Th-Pb geochronology applications is described. Default but editable run-tables enable software identification of secondary ion species analyzed and for characterization of the standard used. Counts obtained for each species may be displayed in plots against analysis time and edited interactively. Count outliers can be automatically identified via a set of editable count-rejection criteria and displayed for assessment. Standard analyses are distinguished from Unknowns by matching of the analysis label with a string specified in the Set-up dialog, and processed separately. A generalized routine writes background-corrected count rates, ratios and uncertainties, plus weighted means and uncertainties for Standards and Unknowns, to a spreadsheet that may be saved as a text-delimited file. Specialized routines process trace-element concentration, 26Al- 26Mg, 53Mn- 53Cr, 60Fe- 60Ni, and Th-U disequilibrium analysis types, and U-Th-Pb isotopic data obtained for zircon, titanite, perovskite, monazite, xenotime and baddeleyite. Correction to measured Pb-isotopic, Pb/U and Pb/Th ratios for the presence of common Pb may be made using measured 204Pb counts, or the 207Pb or 208Pb counts following subtraction from these of the radiogenic component. Common-Pb corrections may be made automatically, using a (user-specified) common-Pb isotopic composition appropriate for that on the sample surface, or for that incorporated within the mineral at the time of its crystallization, depending on whether the 204Pb count rate determined for the Unknown is substantially higher than the average 204Pb count rate for all session standards. Pb/U inter-element fractionation corrections are determined using an interactive log e-log e plot of common-Pb corrected 206Pb/ 238U ratios against any nominated fractionation-sensitive species pair

  9. The adaptation of visual and auditory integration in the barn owl superior colliculus with Spike Timing Dependent Plasticity.

    PubMed

    Huo, Juan; Murray, Alan

    2009-09-01

    To localize a seen object, the superior colliculus of the barn owl integrates the visual and auditory localization cues which are accessed from the sensory system of the brain. These cues are formed as visual and auditory maps. The alignment between visual and auditory maps is very important for accurate localization in prey behavior. Blindness or prism wearing may interfere this alignment. The juvenile barn owl could adapt its auditory map to this mismatch after several weeks training. Here we investigate this process by building a computational model of auditory and visual integration in deep Superior Colliculus (SC). The adaptation of the map alignment is based on activity dependent axon developing in Inferior Colliculus (IC). This axon growing process is instructed by an inhibitory network in SC while the strength of the inhibition is adjusted by Spike Timing Dependent Plasticity (STDP). The simulation results of this model are in line with the biological experiment and support the idea that STDP is involved in the alignment of sensory maps. This model also provides a new spiking neuron based mechanism capable of eliminating the disparity in visual and auditory map integration. PMID:19084371

  10. Analytic approach to co-evolving dynamics in complex networks: dissatisfied adaptive snowdrift game

    NASA Astrophysics Data System (ADS)

    Gräser, Oliver; Xu, Chen; Hui, P. M.

    2011-08-01

    We investigate the formulation of mean-field (MF) approaches for co-evolving dynamic model systems, focusing on the accuracy and validity of different schemes in closing MF equations. Within the context of a recently introduced co-evolutionary snowdrift game in which rational adaptive actions are driven by dissatisfaction in the payoff, we introduce a method to test the validity of closure schemes and analyse the shortcomings of previous schemes. A previous scheme suitable for adaptive epidemic models is shown to be invalid for the model studied here. A binomial-style closure scheme that significantly improves upon the previous schemes is introduced. Fixed-point analysis of the MF equations not only explains the numerical observed transition between a connected state with suppressed cooperation and a highly cooperative disconnected state, but also reveals a previously undetected connected state that exhibits the unusual behaviour of decreasing cooperation as the temptation for uncooperative action drops. We proposed a procedure for selecting proper initial conditions to realize the unusual state in numerical simulations. The effects of the mean number of connections that an agent carries are also studied.

  11. Analytical investigation of adaptive control of radiated inlet noise from turbofan engines

    NASA Technical Reports Server (NTRS)

    Risi, John D.; Burdisso, Ricardo A.

    1994-01-01

    An analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.

  12. Adaptive Optics Analysis of Visual Benefit with Higher-order Aberrations Correction of Human Eye - Poster Paper

    NASA Astrophysics Data System (ADS)

    Xue, Lixia; Dai, Yun; Rao, Xuejun; Wang, Cheng; Hu, Yiyun; Liu, Qian; Jiang, Wenhan

    2008-01-01

    Higher-order aberrations correction can improve visual performance of human eye to some extent. To evaluate how much visual benefit can be obtained with higher-order aberrations correction we developed an adaptive optics vision simulator (AOVS). Dynamic real time optimized modal compensation was used to implement various customized higher-order ocular aberrations correction strategies. The experimental results indicate that higher-order aberrations correction can improve visual performance of human eye comparing with only lower-order aberration correction but the improvement degree and higher-order aberration correction strategy are different from each individual. Some subjects can acquire great visual benefit when higher-order aberrations were corrected but some subjects acquire little visual benefit even though all higher-order aberrations were corrected. Therefore, relative to general lower-order aberrations correction strategy, customized higher-order aberrations correction strategy is needed to obtain optimal visual improvement for each individual. AOVS provides an effective tool for higher-order ocular aberrations optometry for customized ocular aberrations correction.

  13. Visual deprivation leads to gait adaptations that are age- and context-specific: I. Step-time parameters.

    PubMed

    Hallemans, Ann; Beccu, Sofie; Van Loock, Kelly; Ortibus, Els; Truijen, Steven; Aerts, Peter

    2009-07-01

    In children, visual information is crucial for static postural control, although age-related differences exist in the impact of visual perturbation on postural sway. Since static postural control and locomotion are closely related, we expect age-related differences in the impact of visual deprivation on dynamic stability and gait. It is hypothesised that this is related to the important role of vision in postural control. Postural stability and gait was tested in 20 adults and 40 children (3-11 years old) under two different visual conditions: eyes open (EO) and eyes closed (EC). Significant differences were found between EO and EC for postural sway, dimensionless walking speed, dimensionless stride length and duration of double support. Thus, we can state that visual deprivation affects locomotion both in adults and children. Concerning walking speed a significant interaction effect was observed with age. The difference in walking speed between EO and EC is larger in children than in adults. Furthermore, we found significant correlations between postural sway and walking speed, step frequency and stride length. These observations support the hypothesis that gait adaptations in situations of visual deprivation are related to balance problems.

  14. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

    PubMed Central

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R.; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words “GREEN” or “RED” were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying “GREEN” or “RED” had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system. PMID:26958463

  15. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation.

    PubMed

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system. PMID:26958463

  16. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation.

    PubMed

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.

  17. Visual acuity trade-offs and microhabitat-driven adaptation of searching behaviour in psyllids (Hemiptera: Psylloidea: Aphalaridae).

    PubMed

    Farnier, Kevin; Dyer, Adrian G; Taylor, Gary S; Peters, Richard A; Steinbauer, Martin J

    2015-05-15

    Insects have evolved morphological and physiological adaptations in response to selection pressures inherent to their ecology. Consequently, visual performance and acuity often significantly vary between different insect species. Whilst psychophysics has allowed for the accurate determination of visual acuity for some Lepidoptera and Hymenoptera, very little is known about other insect taxa that cannot be trained to positively respond to a given stimulus. In this study, we demonstrate that prior knowledge of insect colour preferences can be used to facilitate acuity testing. We focused on four psyllid species (Hemiptera: Psylloidea: Aphalaridae), namely Ctenarytaina eucalypti, Ctenarytaina bipartita, Anoeconeossa bundoorensis and Glycaspis brimblecombei, that differ in their colour preferences and utilization of different host-plant modules (e.g. apical buds, stems, leaf lamellae) and tested their visual acuity in a modified Y-maze adapted to suit psyllid searching behaviour. Our study revealed that psyllids have visual acuity ranging from 6.3 to 8.7 deg. Morphological measurements for different species showed a close match between inter-ommatidial angles and behaviourally determined visual angles (between 5.5 and 6.6 deg) suggesting detection of colour stimuli at the single ommatidium level. Whilst our data support isometric scaling of psyllids' eyes for C. eucalypti, C. bipartita and G. brimblecombei, a morphological trade-off between light sensitivity and spatial resolution was found in A. bundoorensis. Overall, species whose microhabitat preferences require more movement between modules appear to possess superior visual acuity. The psyllid searching behaviours that we describe with the help of tracking software depict species-specific strategies that presumably evolved to optimize searching for food and oviposition sites.

  18. Modelling rainfall interception by vegetation of variable density using an adapted analytical model. Part 2. Model validation for a tropical upland mixed cropping system

    NASA Astrophysics Data System (ADS)

    van Dijk, A. I. J. M.; Bruijnzeel, L. A.

    2001-07-01

    To improve the description of rainfall partitioning by a vegetation canopy that changes in time a number of adaptations to the revised analytical model for rainfall interception by sparse canopies [J. Hydrol., 170 (1995) 79] was proposed in the first of two papers. The current paper presents an application of this adapted analytical model to simulate throughfall, stemflow and interception as measured in a mixed agricultural cropping system involving cassava, maize and rice during two seasons of growth and serial harvesting in upland West Java, Indonesia. Measured interception losses were 18 and 8% during the two measuring periods, while stemflow fractions were estimated at 2 and 4%, respectively. The main reasons for these discrepancies were differences in vegetation density and composition, as well as differences in the exposure of the two sites used in the two respective years. Functions describing the development of the leaf area index of each of the component crops in time were developed. Leaf area index (ranging between 0.7 and 3.8) was related to canopy cover fraction (0.41-0.94). Using average values and time series of the respective parameters, interception losses were modelled using both the revised analytical model and the presently adapted version. The results indicate that the proposed model adaptations substantially improve the performance of the analytical model and provide a more solid base for parameterisation of the analytical model in vegetation of variable density.

  19. Visualization of Time-Series Sensor Data to Inform the Design of Just-In-Time Adaptive Stress Interventions

    PubMed Central

    Sharmin, Moushumi; Raij, Andrew; Epstien, David; Nahum-Shani, Inbal; Beck, J. Gayle; Vhaduri, Sudip; Preston, Kenzie; Kumar, Santosh

    2015-01-01

    We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time, a need for representation at multiple granularities, interperson variability, and limited understanding of JITAI design requirements due to its novelty. We propose four new visualizations based on one million minutes of sensor data (n=70). We evaluate our visualizations with stress researchers (n=6) to gain first insights into its usability and usefulness in JITAI design. Our results indicate that spatio-temporal visualizations help identify and explain between- and within-person variability in stress patterns and contextual visualizations enable decisions regarding the timing, content, and modality of intervention. Interestingly, a granular representation is considered informative but noise-prone; an abstract representation is the preferred starting point for designing JITAIs. PMID:26539566

  20. Adapting Artworks for People Who Are Blind or Visually Impaired Using Raised Printing

    ERIC Educational Resources Information Center

    Krivec, Tjaša; Muck, Tadeja; Germadnik, Rolanda Fugger; Majnaric, Igor; Golob, Gorazd

    2014-01-01

    Everyone has the right to freely participate in the cultural life of the community (United Nations, 2012). In Europe and around the globe, many efforts have been made in order to include people with visual impairments and blindness into the cultural life. The objects and artifacts exhibited in museums for people with visual impairments are…

  1. Night vision in barn owls: visual acuity and contrast sensitivity under dark adaptation.

    PubMed

    Orlowski, Julius; Harmening, Wolf; Wagner, Hermann

    2012-12-06

    Barn owls are effective nocturnal predators. We tested their visual performance at low light levels and determined visual acuity and contrast sensitivity of three barn owls by their behavior at stimulus luminances ranging from photopic to fully scotopic levels (23.5 to 1.5 × 10⁻⁶). Contrast sensitivity and visual acuity decreased only slightly from photopic to scotopic conditions. Peak grating acuity was at mesopic (4 × 10⁻² cd/m²) conditions. Barn owls retained a quarter of their maximal acuity when luminance decreased by 5.5 log units. We argue that the visual system of barn owls is designed to yield as much visual acuity under low light conditions as possible, thereby sacrificing resolution at photopic conditions.

  2. Data-driven approach to Type Ia supernovae: variable selection on the peak luminosity and clustering in visual analytics

    NASA Astrophysics Data System (ADS)

    Uemura, Makoto; Kawabata, Koji S.; Ikeda, Shiro; Maeda, Keiichi; Wu, Hsiang-Yun; Watanabe, Kazuho; Takahashi, Shigeo; Fujishiro, Issei

    2016-03-01

    Type Ia supernovae (SNIa) have an almost uniform peak luminosity, so that they are used as “standard candle” to estimate distances to galaxies in cosmology. In this article, we introduce our two recent works on SNIa based on data-driven approach. The diversity in the peak luminosity of SNIa can be reduced by corrections in several variables. The color and decay rate have been used as the explanatory variables of the peak luminosity in past studies. However, it is proposed that their spectral data could give a better model of the peak luminosity. We use cross-validation in order to control the generalization error and a LASSO-type estimator in order to choose the set of variables. Using 78 samples and 276 candidates of variables, we confirm that the peak luminosity depends on the color and decay rate. Our analysis does not support adding any other variables in order to have a better generalization error. On the other hand, this analysis is based on the assumption that SNIa originate in a single population, while it is not trivial. Indeed, several sub-types possibly having different nature have been proposed. We used a visual analytics tool for the asymmetric biclustering method to find both a good set of variables and samples at the same time. Using 14 variables and 132 samples, we found that SNIa can be divided into two categories by the expansion velocity of ejecta. Those examples demonstrate that the data-driven approach is useful for high-dimensional large-volume data which becomes common in modern astronomy.

  3. Visualizing and Tracking Evolving Features in 3D Unstructured and Adaptive Datasets

    SciTech Connect

    Silver, D.; Zabusky, N.

    2002-08-01

    The massive amounts of time-varying datasets being generated demand new visualization and quantification techniques. Visualization alone is not sufficient. Without proper measurement information/computations real science cannot be done. Our focus is this work was to combine visualization with quantification of the data to allow for advanced querying and searching. As part of this proposal, we have developed a feature extraction adn tracking methodology which allows researcher to identify features of interest and follow their evolution over time. The implementation is distributed and operates over data In-situ: where it is stored and when it was computed.

  4. Towards Adaptive Educational Assessments: Predicting Student Performance using Temporal Stability and Data Analytics in Learning Management Systems

    SciTech Connect

    Thakur, Gautam; Olama, Mohammed M; McNair, Wade; Sukumar, Sreenivas R

    2014-01-01

    Data-driven assessments and adaptive feedback are becoming a cornerstone research in educational data analytics and involve developing methods for exploring the unique types of data that come from the educational context. For example, predicting college student performance is crucial for both the students and educational institutions. It can support timely intervention to prevent students from failing a course, increasing efficacy of advising functions, and improving course completion rate. In this paper, we present our efforts in using data analytics that enable educationists to design novel data-driven assessment and feedback mechanisms. In order to achieve this objective, we investigate temporal stability of students grades and perform predictive analytics on academic data collected from 2009 through 2013 in one of the most commonly used learning management systems, called Moodle. First, we have identified the data features useful for assessments and predicting student outcomes such as students scores in homework assignments, quizzes, exams, in addition to their activities in discussion forums and their total Grade Point Average(GPA) at the same term they enrolled in the course. Second, time series models in both frequency and time domains are applied to characterize the progression as well as overall projections of the grades. In particular, the model analyzed the stability as well as fluctuation of grades among students during the collegiate years (from freshman to senior) and disciplines. Third, Logistic Regression and Neural Network predictive models are used to identify students as early as possible who are in danger of failing the course they are currently enrolled in. These models compute the likelihood of any given student failing (or passing) the current course. The time series analysis indicates that assessments and continuous feedback are critical for freshman and sophomores (even with easy courses) than for seniors, and those assessments may be

  5. Flicker Adaptation of Low-Level Cortical Visual Neurons Contributes to Temporal Dilation

    ERIC Educational Resources Information Center

    Ortega, Laura; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Nonsensory factors, such as increased arousal and attention, have been thought to mediate this flicker-based temporal-dilation aftereffect. In this study, we provide evidence that adaptation of low-level cortical visual…

  6. VIDET: A Visual Authoring Tool for Adaptive Websites Tailored to Non-Programmer Teachers

    ERIC Educational Resources Information Center

    Armani, Jacopo

    2005-01-01

    So far educational adaptive technologies have proven their effectiveness only in small-scale lab courses, thus they still wait for being released to the large community of educators. Among the reasons, there is the difficult task of designing and authoring an interactive adaptive course, especially for non-technical group of educators. In this…

  7. Adaptive Blood Glucose Monitoring and Insulin Measurement Devices for Visually Impaired Persons.

    ERIC Educational Resources Information Center

    Petzinger, R. A.

    1993-01-01

    This article describes devices that people with visual impairments and diabetes can use to monitor blood glucose levels and measure insulin. A table lists devices, their manufacturers (including address and telephone number), and comments about the devices. (DB)

  8. Query-driven visualization of time-varying adaptive mesh refinement data.

    PubMed

    Gosink, Luke J; Anderson, John C; Bethel, E Wes; Joy, Kenneth I

    2008-01-01

    The visualization and analysis of AMR-based simulations is integral to the process of obtaining new insight in scientific research. We present a new method for performing query-driven visualization and analysis on AMR data, with specific emphasis on time-varying AMR data. Our work introduces a new method that directly addresses the dynamic spatial and temporal properties of AMR grids that challenge many existing visualization techniques. Further, we present the first implementation of query-driven visualization on the GPU that uses a GPU-based indexing structure to both answer queries and efficiently utilize GPU memory. We apply our method to two different science domains to demonstrate its broad applicability.

  9. Query-Driven Visualization of Time-Varying Adaptive Mesh Refinement Data

    SciTech Connect

    Gosink, Luke J.; Anderson, John C.; Bethel, E. Wes; Joy, Kenneth I.

    2008-08-01

    The visualization and analysis of AMR-based simulations is integral to the process of obtaining new insight in scientific research. We present a new method for performing query-driven visualization and analysis on AMR data, with specific emphasis on time-varying AMR data. Our work introduces a new method that directly addresses the dynamic spatial and temporal properties of AMR grids which challenge many existing visualization techniques. Further, we present the first implementation of query-driven visualization on the GPU that uses a GPU-based indexing structure to both answer queries and efficiently utilize GPU memory. We apply our method to two different science domains to demonstrate its broad applicability.

  10. Perceptual suppression revealed by adaptive multi-scale entropy analysis of local field potential in monkey visual cortex.

    PubMed

    Hu, Meng; Liang, Hualou

    2013-04-01

    Generalized flash suppression (GFS), in which a salient visual stimulus can be rendered invisible despite continuous retinal input, provides a rare opportunity to directly study the neural mechanism of visual perception. Previous work based on linear methods, such as spectral analysis, on local field potential (LFP) during GFS has shown that the LFP power at distinctive frequency bands are differentially modulated by perceptual suppression. Yet, the linear method alone may be insufficient for the full assessment of neural dynamic due to the fundamentally nonlinear nature of neural signals. In this study, we set forth to analyze the LFP data collected from multiple visual areas in V1, V2 and V4 of macaque monkeys while performing the GFS task using a nonlinear method - adaptive multi-scale entropy (AME) - to reveal the neural dynamic of perceptual suppression. In addition, we propose a new cross-entropy measure at multiple scales, namely adaptive multi-scale cross-entropy (AMCE), to assess the nonlinear functional connectivity between two cortical areas. We show that: (1) multi-scale entropy exhibits percept-related changes in all three areas, with higher entropy observed during perceptual suppression; (2) the magnitude of the perception-related entropy changes increases systematically over successive hierarchical stages (i.e. from lower areas V1 to V2, up to higher area V4); and (3) cross-entropy between any two cortical areas reveals higher degree of asynchrony or dissimilarity during perceptual suppression, indicating a decreased functional connectivity between cortical areas. These results, taken together, suggest that perceptual suppression is related to a reduced functional connectivity and increased uncertainty of neural responses, and the modulation of perceptual suppression is more effective at higher visual cortical areas. AME is demonstrated to be a useful technique in revealing the underlying dynamic of nonlinear/nonstationary neural signal.

  11. The selectivity of responses to red-green colour and achromatic contrast in the human visual cortex: an fMRI adaptation study.

    PubMed

    Mullen, Kathy T; Chang, Dorita H F; Hess, Robert F

    2015-12-01

    There is controversy as to how responses to colour in the human brain are organized within the visual pathways. A key issue is whether there are modular pathways that respond selectively to colour or whether there are common neural substrates for both colour and achromatic (Ach) contrast. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the responses of early and extrastriate visual areas to colour and Ach contrast. High-contrast red-green (RG) and Ach sinewave rings (0.5 cycles/degree, 2 Hz) were used as both adapting stimuli and test stimuli in a block design. We found robust adaptation to RG or Ach contrast in all visual areas. Cross-adaptation between RG and Ach contrast occurred in all areas indicating the presence of integrated, colour and Ach responses. Notably, we revealed contrasting trends for the two test stimuli. For the RG test, unselective processing (robust adaptation to both RG and Ach contrast) was most evident in the early visual areas (V1 and V2), but selective responses, revealed as greater adaptation between the same stimuli than cross-adaptation between different stimuli, emerged in the ventral cortex, in V4 and VO in particular. For the Ach test, unselective responses were again most evident in early visual areas but Ach selectivity emerged in the dorsal cortex (V3a and hMT+). Our findings support a strong presence of integrated mechanisms for colour and Ach contrast across the visual hierarchy, with a progression towards selective processing in extrastriate visual areas.

  12. Internal model of gravity for hand interception: parametric adaptation to zero-gravity visual targets on Earth.

    PubMed

    Zago, Myrka; Lacquaniti, Francesco

    2005-08-01

    Internal model is a neural mechanism that mimics the dynamics of an object for sensory motor or cognitive functions. Recent research focuses on the issue of whether multiple internal models are learned and switched to cope with a variety of conditions, or single general models are adapted by tuning the parameters. Here we addressed this issue by investigating how the manual interception of a moving target changes with changes of the visual environment. In our paradigm, a virtual target moves vertically downward on a screen with different laws of motion. Subjects are asked to punch a hidden ball that arrives in synchrony with the visual target. By using several different protocols, we systematically found that subjects do not develop a new internal model appropriate for constant speed targets, but they use the default gravity model and reduce the central processing time. The results imply that adaptation to zero-gravity targets involves a compression of temporal processing through the cortical and subcortical regions interconnected with the vestibular cortex, which has previously been shown to be the site of storage of the internal model of gravity. PMID:15817649

  13. Adaptive pacing of visual stimulation for fMRI studies involving overt speech.

    PubMed

    Grabowski, Thomas J; Bauer, Matthew D; Foreman, Derek; Mehta, Sonya; Eaton, Brent L; Graves, William W; Defoe, Dori L; Bolinger, Lizann

    2006-02-01

    We report the development of an interactive approach to single-word language production studies in fMRI. The approach, adaptive pacing, involves real-time adjustment of stimulus presentation times based on individual subject performance timing and content. At the same time, it maintains a stochastic distribution of interstimulus intervals to avoid confounding task covariates with speech-related signal variance. Adaptive pacing of overt speech production is an example of a new class of paradigms that require an observational approach to data acquisition and benefit from a "time-aware" acquisition and processing environment. The advantages of adaptive pacing in fMRI of impaired subjects are expected to be the acquisition of more informative data per unit time, less contamination of data by correlates of non-language processes such as emotion, and facilitation of experiments that combine normal and impaired subjects. PMID:16303319

  14. Optical properties of retinal tissue and the potential of adaptive optics to visualize retinal ganglion cells in vivo.

    PubMed

    Prasse, Martina; Rauscher, Franziska Georgia; Wiedemann, Peter; Reichenbach, Andreas; Francke, Mike

    2013-08-01

    Many efforts have been made to improve the diagnostic tools used to identify and to estimate the progress of ganglion cell and nerve fibre degeneration in glaucoma. Imaging by optical coherence tomography and measurements of the dimensions of the optic nerve head and the nerve fibre layer in central retinal areas is currently used to estimate the grade of pathological changes. The visualization and quantification of ganglion cells and nerve fibres directly in patients would dramatically improve glaucoma diagnostics. We have investigated the optical properties of cellular structures of retinal tissue in order to establish a means of visualizing and quantifying ganglion cells in the living retina without staining. We have characterized the optical properties of retinal tissue in several species including humans. Nerve fibres, blood vessels, ganglion cells and their cell processes have been visualized at high image resolution by means of the reflection mode of a confocal laser scanning microscope. The potential of adaptive optics in current imaging systems and the possibilities of imaging single ganglion cells non-invasively in patients are discussed.

  15. Scalable Adaptive Graphics Environment (SAGE) Software for the Visualization of Large Data Sets on a Video Wall

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary; Srikishen, Jayanthi; Edwards, Rita; Cross, David; Welch, Jon; Smith, Matt

    2013-01-01

    The use of collaborative scientific visualization systems for the analysis, visualization, and sharing of "big data" available from new high resolution remote sensing satellite sensors or four-dimensional numerical model simulations is propelling the wider adoption of ultra-resolution tiled display walls interconnected by high speed networks. These systems require a globally connected and well-integrated operating environment that provides persistent visualization and collaboration services. This abstract and subsequent presentation describes a new collaborative visualization system installed for NASA's Shortterm Prediction Research and Transition (SPoRT) program at Marshall Space Flight Center and its use for Earth science applications. The system consists of a 3 x 4 array of 1920 x 1080 pixel thin bezel video monitors mounted on a wall in a scientific collaboration lab. The monitors are physically and virtually integrated into a 14' x 7' for video display. The display of scientific data on the video wall is controlled by a single Alienware Aurora PC with a 2nd Generation Intel Core 4.1 GHz processor, 32 GB memory, and an AMD Fire Pro W600 video card with 6 mini display port connections. Six mini display-to-dual DVI cables are used to connect the 12 individual video monitors. The open source Scalable Adaptive Graphics Environment (SAGE) windowing and media control framework, running on top of the Ubuntu 12 Linux operating system, allows several users to simultaneously control the display and storage of high resolution still and moving graphics in a variety of formats, on tiled display walls of any size. The Ubuntu operating system supports the open source Scalable Adaptive Graphics Environment (SAGE) software which provides a common environment, or framework, enabling its users to access, display and share a variety of data-intensive information. This information can be digital-cinema animations, high-resolution images, high-definition video

  16. Scalable Adaptive Graphics Environment (SAGE) Software for the Visualization of Large Data Sets on a Video Wall

    NASA Astrophysics Data System (ADS)

    Jedlovec, G.; Srikishen, J.; Edwards, R.; Cross, D.; Welch, J. D.; Smith, M. R.

    2013-12-01

    The use of collaborative scientific visualization systems for the analysis, visualization, and sharing of 'big data' available from new high resolution remote sensing satellite sensors or four-dimensional numerical model simulations is propelling the wider adoption of ultra-resolution tiled display walls interconnected by high speed networks. These systems require a globally connected and well-integrated operating environment that provides persistent visualization and collaboration services. This abstract and subsequent presentation describes a new collaborative visualization system installed for NASA's Short-term Prediction Research and Transition (SPoRT) program at Marshall Space Flight Center and its use for Earth science applications. The system consists of a 3 x 4 array of 1920 x 1080 pixel thin bezel video monitors mounted on a wall in a scientific collaboration lab. The monitors are physically and virtually integrated into a 14' x 7' for video display. The display of scientific data on the video wall is controlled by a single Alienware Aurora PC with a 2nd Generation Intel Core 4.1 GHz processor, 32 GB memory, and an AMD Fire Pro W600 video card with 6 mini display port connections. Six mini display-to-dual DVI cables are used to connect the 12 individual video monitors. The open source Scalable Adaptive Graphics Environment (SAGE) windowing and media control framework, running on top of the Ubuntu 12 Linux operating system, allows several users to simultaneously control the display and storage of high resolution still and moving graphics in a variety of formats, on tiled display walls of any size. The Ubuntu operating system supports the open source Scalable Adaptive Graphics Environment (SAGE) software which provides a common environment, or framework, enabling its users to access, display and share a variety of data-intensive information. This information can be digital-cinema animations, high-resolution images, high-definition video

  17. Spectral Tuning of Killer Whale (Orcinus orca) Rhodopsin: Evidence for Positive Selection and Functional Adaptation in a Cetacean Visual Pigment.

    PubMed

    Dungan, Sarah Z; Kosyakov, Alexander; Chang, Belinda S W

    2016-02-01

    Cetaceans have undergone a remarkable evolutionary transition that was accompanied by many sensory adaptations, including modification of the visual system for underwater environments. Recent sequencing of cetacean genomes has made it possible to begin exploring the molecular basis of these adaptations. In this study we use in vitro expression methods to experimentally characterize the first step of the visual transduction cascade, the light activation of rhodopsin, for the killer whale. To investigate the spectral effects of amino acid substitutions thought to correspond with absorbance shifts relative to terrestrial mammals, we used the orca gene as a background for the first site-directed mutagenesis experiments in a cetacean rhodopsin. The S292A mutation had the largest effect, and was responsible for the majority of the spectral difference between killer whale and bovine (terrestrial) rhodopsin. Using codon-based likelihood models, we also found significant evidence for positive selection in cetacean rhodopsin sequences, including on spectral tuning sites we experimentally mutated. We then investigated patterns of ecological divergence that may be correlated with rhodopsin functional variation by using a series of clade models that partitioned the data set according to phylogeny, habitat, and foraging depth zone. Only the model partitioning according to depth was significant. This suggests that foraging dives might be a selective regime influencing cetacean rhodopsin divergence, and our experimental results indicate that spectral tuning may be playing an adaptive role in this process. Our study demonstrates that combining computational and experimental methods is crucial for gaining insight into the selection pressures underlying molecular evolution. PMID:26486871

  18. Spectral Tuning of Killer Whale (Orcinus orca) Rhodopsin: Evidence for Positive Selection and Functional Adaptation in a Cetacean Visual Pigment.

    PubMed

    Dungan, Sarah Z; Kosyakov, Alexander; Chang, Belinda S W

    2016-02-01

    Cetaceans have undergone a remarkable evolutionary transition that was accompanied by many sensory adaptations, including modification of the visual system for underwater environments. Recent sequencing of cetacean genomes has made it possible to begin exploring the molecular basis of these adaptations. In this study we use in vitro expression methods to experimentally characterize the first step of the visual transduction cascade, the light activation of rhodopsin, for the killer whale. To investigate the spectral effects of amino acid substitutions thought to correspond with absorbance shifts relative to terrestrial mammals, we used the orca gene as a background for the first site-directed mutagenesis experiments in a cetacean rhodopsin. The S292A mutation had the largest effect, and was responsible for the majority of the spectral difference between killer whale and bovine (terrestrial) rhodopsin. Using codon-based likelihood models, we also found significant evidence for positive selection in cetacean rhodopsin sequences, including on spectral tuning sites we experimentally mutated. We then investigated patterns of ecological divergence that may be correlated with rhodopsin functional variation by using a series of clade models that partitioned the data set according to phylogeny, habitat, and foraging depth zone. Only the model partitioning according to depth was significant. This suggests that foraging dives might be a selective regime influencing cetacean rhodopsin divergence, and our experimental results indicate that spectral tuning may be playing an adaptive role in this process. Our study demonstrates that combining computational and experimental methods is crucial for gaining insight into the selection pressures underlying molecular evolution.

  19. Low-Cost Laboratory Adaptations for Precollege Students Who Are Blind or Visually Impaired

    NASA Astrophysics Data System (ADS)

    Supalo, Cary A.; Mallouk, Thomas E.; Rankel, Lillian; Amorosi, Christeallia; Graybill, Cameala M.

    2008-02-01

    The creative application of low-cost, readily available materials and techniques promotes inclusion and provides accessibility in the classroom and laboratory for students who are blind or have low vision. Difficulties encountered by these students include operation of laboratory equipment, execution of ordinary laboratory procedures, and use of molecular structure models, all of which typically involve visual observations. The low-cost tools described in this article can help teachers provide more independent and rewarding laboratory and classroom experiences for these students.

  20. Exploiting the User: Adapting Personas for Use in Security Visualization Design

    SciTech Connect

    Stoll, Jennifer C.; McColgin, David W.; Gregory, Michelle L.; Crow, Vernon L.; Edwards, Keith

    2007-10-29

    It has long been noted that visual representations of complex information can facilitate rapid understanding of data {citation], even with respect to ComSec applications {citation]. Recognizing that visualizations can increase usability in ComSec applications, [Zurko, Sasse] have argued that there is a need to create more usable security visualizations. (VisSec) However, usability of applications generally fall into the domain of Human Computer Interaction (HCI), which generally relies on heavy-weight user-centered design (UCD) processes. For example, the UCD process can involve many prototype iterations, or an ethnographic field study that can take months to complete. The problem is that VisSec projects generally do not have the resources to perform ethnographic field studies, or to employ complex UCD methods. They often are running on tight deadlines and budgets that can not afford standard UCD methods. In order to help resolve the conflict of needing more usable designs in ComSec, but not having the resources to employ complex UCD methods, in this paper we offer a stripped-down lighter weight version of a UCD process which can help with capturing user requirements. The approach we use is personas which a user requirements capturing method arising out of the Participatory Design philosophy [Grudin02].

  1. Adaptive enhancement and visualization techniques for 3D THz images of breast cancer tumors

    NASA Astrophysics Data System (ADS)

    Wu, Yuhao; Bowman, Tyler; Gauch, John; El-Shenawee, Magda

    2016-03-01

    This paper evaluates image enhancement and visualization techniques for pulsed terahertz (THz) images of tissue samples. Specifically, our research objective is to effectively differentiate between heterogeneous regions of breast tissues that contain tumors diagnosed as triple negative infiltrating ductal carcinoma (IDC). Tissue slices and blocks of varying thicknesses were prepared and scanned using our lab's THz pulsed imaging system. One of the challenges we have encountered in visualizing the obtained images and differentiating between healthy and cancerous regions of the tissues is that most THz images have a low level of details and narrow contrast, making it difficult to accurately identify and visualize the margins around the IDC. To overcome this problem, we have applied and evaluated a number of image processing techniques to the scanned 3D THz images. In particular, we employed various spatial filtering and intensity transformation techniques to emphasize the small details in the images and adjust the image contrast. For each of these methods, we investigated how varying filter sizes and parameters affect the amount of enhancement applied to the images. Our experimentation shows that several image processing techniques are effective in producing THz images of breast tissue samples that contain distinguishable details, making further segmentation of the different image regions promising.

  2. [application of the analytical transmission electron microscopy techniques for detection, identification and visualization of localization of nanoparticles of titanium and cerium oxides in mammalian cells].

    PubMed

    Shebanova, A S; Bogdanov, A G; Ismagulova, T T; Feofanov, A V; Semenyuk, P I; Muronets, V I; Erokhina, M V; Onishchenko, G E; Kirpichnikov, M P; Shaitan, K V

    2014-01-01

    This work represents the results of the study on applicability of the modern methods of analytical transmission electron microscopy for detection, identification and visualization of localization of nanoparticles of titanium and cerium oxides in A549 cell, human lung adenocarcinoma cell line. A comparative analysis of images of the nanoparticles in the cells obtained in the bright field mode of transmission electron microscopy, under dark-field scanning transmission electron microscopy and high-angle annular dark field scanning transmission electron was performed. For identification of nanoparticles in the cells the analytical techniques, energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy, were compared when used in the mode of obtaining energy spectrum from different particles and element mapping. It was shown that the method for electron tomography is applicable to confirm that nanoparticles are localized in the sample but not coated by contamination. The possibilities and fields of utilizing different techniques for analytical transmission electron microscopy for detection, visualization and identification of nanoparticles in the biological samples are discussed.

  3. Oak Ridge Bio-surveillance Toolkit (ORBiT): Integrating Big-Data Analytics with Visual Analysis for Public Health Dynamics

    SciTech Connect

    Ramanathan, Arvind; Pullum, Laura L; Steed, Chad A; Chennubhotla, Chakra; Quinn, Shannon

    2013-01-01

    In this position paper, we describe the design and implementation of the Oak Ridge Bio-surveillance Toolkit (ORBiT): a collection of novel statistical and machine learning tools implemented for (1) integrating heterogeneous traditional (e.g. emergency room visits, prescription sales data, etc.) and non-traditional (social media such as Twitter and Instagram) data sources, (2) analyzing large-scale datasets and (3) presenting the results from the analytics as a visual interface for the end-user to interact and provide feedback. We present examples of how ORBiT can be used to summarize ex- tremely large-scale datasets effectively and how user interactions can translate into the data analytics process for bio-surveillance. We also present a strategy to estimate parameters relevant to dis- ease spread models from near real time data feeds and show how these estimates can be integrated with disease spread models for large-scale populations. We conclude with a perspective on how integrating data and visual analytics could lead to better forecasting and prediction of disease spread as well as improved awareness of disease susceptible regions.

  4. Adaptive learning in a compartmental model of visual cortex—how feedback enables stable category learning and refinement

    PubMed Central

    Layher, Georg; Schrodt, Fabian; Butz, Martin V.; Neumann, Heiko

    2014-01-01

    The categorization of real world objects is often reflected in the similarity of their visual appearances. Such categories of objects do not necessarily form disjunct sets of objects, neither semantically nor visually. The relationship between categories can often be described in terms of a hierarchical structure. For instance, tigers and leopards build two separate mammalian categories, both of which are subcategories of the category Felidae. In the last decades, the unsupervised learning of categories of visual input stimuli has been addressed by numerous approaches in machine learning as well as in computational neuroscience. However, the question of what kind of mechanisms might be involved in the process of subcategory learning, or category refinement, remains a topic of active investigation. We propose a recurrent computational network architecture for the unsupervised learning of categorial and subcategorial visual input representations. During learning, the connection strengths of bottom-up weights from input to higher-level category representations are adapted according to the input activity distribution. In a similar manner, top-down weights learn to encode the characteristics of a specific stimulus category. Feedforward and feedback learning in combination realize an associative memory mechanism, enabling the selective top-down propagation of a category's feedback weight distribution. We suggest that the difference between the expected input encoded in the projective field of a category node and the current input pattern controls the amplification of feedforward-driven representations. Large enough differences trigger the recruitment of new representational resources and the establishment of additional (sub-) category representations. We demonstrate the temporal evolution of such learning and show how the proposed combination of an associative memory with a modulatory feedback integration successfully establishes category and subcategory representations

  5. Adaptive gene loss reflects differences in the visual ecology of basal vertebrates.

    PubMed

    Davies, Wayne L; Collin, Shaun P; Hunt, David M

    2009-08-01

    The agnathans (lampreys and hagfishes) are representatives of the jawless fishes and constitute the first lineage of extant vertebrates to evolve within chordate phylogenetic history. Previously, we showed that the southern hemisphere pouched lamprey Geotria australis has the potential for pentachromacy with the expression of five visual pigment (opsin) genes (LWS, SWS1, SWS2, RhA, and RhB) in five different cone-like photoreceptors for life in a brightly lit environment exposed to a broad spectrum of light. In contrast, the northern hemisphere sea lamprey Petromyzon marinus dwells in a wide range of depths that are relatively deeper than the epipelagic waters inhabited by G. australis. Thus, the light levels of the habitat in which the sea lamprey resides are greatly diminished and different regions of the light spectrum are differentially absorbed. Therefore, the visual systems of these two species of lamprey constitute a natural experiment in which to study the selection pressures underlying opsin gene expression and the evolution of color discrimination. By analyzing the opsin genes of P. marinus, we show the expression of two intact retinal opsins, RhA and LWS, which, when regenerated with 11-cis retinal, give peak spectral sensitivities (lambda(max) values) of 501 and 536 nm, respectively. In contrast to G. australis, the genome of P. marinus possesses remnants of SWS1 and SWS2 pseudogenes, which with the loss of RhB, suggests that P. marinus is a dichromat. Using site-directed mutagenesis, we show that a single amino acid substitution (Ser to Pro) at site 164 is responsible for a blue shift of 19 nm of the LWS visual pigment of P. marinus compared with G. australis, which may reflect habitat differences between the two species. Based on these studies, we propose that gene loss (or duplication) and subsequent mutation plays an important role in the evolution of color vision and that the complement and tuning of these visual pigments reflect the ecology and

  6. An indirect adaptive neural control of a visual-based quadrotor robot for pursuing a moving target.

    PubMed

    Shirzadeh, Masoud; Amirkhani, Abdollah; Jalali, Aliakbar; Mosavi, Mohammad R

    2015-11-01

    This paper aims to use a visual-based control mechanism to control a quadrotor type aerial robot which is in pursuit of a moving target. The nonlinear nature of a quadrotor, on the one hand, and the difficulty of obtaining an exact model for it, on the other hand, constitute two serious challenges in designing a controller for this UAV. A potential solution for such problems is the use of intelligent control methods such as those that rely on artificial neural networks and other similar approaches. In addition to the two mentioned problems, another problem that emerges due to the moving nature of a target is the uncertainty that exists in the target image. By employing an artificial neural network with a Radial Basis Function (RBF) an indirect adaptive neural controller has been designed for a quadrotor robot in search of a moving target. The results of the simulation for different paths show that the quadrotor has efficiently tracked the moving target.

  7. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  8. Adaptive temporal integration of motion in direction-selective neurons in macaque visual cortex.

    PubMed

    Bair, Wyeth; Movshon, J Anthony

    2004-08-18

    Direction-selective neurons in the primary visual cortex (V1) and the extrastriate motion area MT/V5 constitute a critical channel that links early cortical mechanisms of spatiotemporal integration to downstream signals that underlie motion perception. We studied how temporal integration in direction-selective cells depends on speed, spatial frequency (SF), and contrast using randomly moving sinusoidal gratings and spike-triggered average (STA) analysis. The window of temporal integration revealed by the STAs varied substantially with stimulus parameters, extending farther back in time for slow motion, high SF, and low contrast. At low speeds and high SF, STA peaks were larger, indicating that a single spike often conveyed more information about the stimulus under conditions in which the mean firing rate was very low. The observed trends were similar in V1 and MT and offer a physiological correlate for a large body of psychophysical data on temporal integration. We applied the same visual stimuli to a model of motion detection based on oriented linear filters (a motion energy model) that incorporated an integrate-and-fire mechanism and found that it did not account for the neuronal data. Our results show that cortical motion processing in V1 and in MT is highly nonlinear and stimulus dependent. They cast considerable doubt on the ability of simple oriented filter models to account for the output of direction-selective neurons in a general manner. Finally, they suggest that spike rate tuning functions may miss important aspects of the neural coding of motion for stimulus conditions that evoke low firing rates. PMID:15317857

  9. Adapting an existing visualization application for browser-based deployment: A case study from the Tropical Rainfall Measuring Mission

    NASA Astrophysics Data System (ADS)

    Kelley, Owen A.

    2013-02-01

    THOR, the Tool for High-resolution Observation Review, is a data viewer for the Tropical Rainfall Measuring Mission (TRMM) and the upcoming Global Precipitation Measurement (GPM) mission. THOR began as a desktop application, but now it can be accessed with a web browser, making THOR one of the first online tools for visualizing TRMM satellite data (http://pps.gsfc.nasa.gov/thor). In this effort, the reuse of the existing visualization code was maximized and the complexity of new code was minimized by avoiding unnecessary functionality, frameworks, or libraries. The simplicity of this approach makes it potentially attractive to researchers wishing to adapt their visualization applications for online deployment. To enable THOR to run within a web browser, three new pieces of code are written. First, the graphical user interface (GUI) of the desktop application is translated into HTML, JavaScript, and CSS. Second, a simple communication mechanism is developed over HTTP. Third, a virtual GUI is created on the server that interfaces with the image-generating routines of the existing desktop application so that these routines do not need to be modified for online use. While the basic functionality of THOR is now available online, prototyping is ongoing for enhanced 3D imaging and other aspects of both THOR Desktop and THOR Online. Because TRMM data products are complex and periodically reprocessed with improved algorithms, having a tool such as THOR is important to analysts at the Precipitation Processing System where the algorithms are tested and the products generated, stored, and distributed. Researchers also have found THOR useful for taking a first look at individual files before writing their own software to perform specialized calculations and analyses.

  10. Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies.

    PubMed

    Boccia, M; Barbetti, S; Piccardi, L; Guariglia, C; Ferlazzo, F; Giannini, A M; Zaidel, D W

    2016-01-01

    Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processes.

  11. Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies.

    PubMed

    Boccia, M; Barbetti, S; Piccardi, L; Guariglia, C; Ferlazzo, F; Giannini, A M; Zaidel, D W

    2016-01-01

    Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processes. PMID:26619805

  12. moocRP: Enabling Open Learning Analytics with an Open Source Platform for Data Distribution, Analysis, and Visualization

    ERIC Educational Resources Information Center

    Pardos, Zachary A.; Whyte, Anthony; Kao, Kevin

    2016-01-01

    In this paper, we address issues of transparency, modularity, and privacy with the introduction of an open source, web-based data repository and analysis tool tailored to the Massive Open Online Course community. The tool integrates data request/authorization and distribution workflow features as well as provides a simple analytics module upload…

  13. Visual acuity-adaptive detail enhancement and shadow noise reduction for iCAM06-based HDR imaging

    NASA Astrophysics Data System (ADS)

    Lee, Geun-Young; Lee, Sung-Hak; Kwon, Hyuk-Ju; Sohng, Kyu-Ik

    2015-04-01

    An image appearance model is extremely useful for high-dynamic-range image (HDRI) rendering. However, the base-detail separation and the tone compression process for tonal control cause degradations in image quality. This study focuses on the de-saturation, reduced contrast, and noise problems in dark regions that occur through HDRI-rendering. First, we discuss de-saturation compensation using a bilateral filter that is based on the visual acuity characteristics of various illuminant levels. The edge stop function of the bilateral filter in iCAM06 is adaptively modified according to the illuminant information. Second, to reduce the magnified noise in the dark regions caused by tone mapping, the shadow regions are detected by an object's intensity and illuminant level, and then the noise of the detected regions is reduced using a luminance-adaptive coring function. Finally, we confirmed the enhanced color saturation, image contrast, and reduced noise in shadow regions through the application of the proposed methods.

  14. Adaptation of visually evoked responses of relay cells in the dorsal lateral geniculate nucleus of the cat following prolonged exposure to drifting gratings.

    PubMed

    Shou, T; Li, X; Zhou, Y; Hu, B

    1996-01-01

    Adaptation of visual cortical cells' responses is observed following repeated presentation of grating stimuli. Grating adaptation is believed to exist only at the cortical level. The purpose of this study was to see if grating adaptation also occurs in the lateral geniculate nucleus. We studied the responses of 164 relay cells in layer A and A1 of the dorsal lateral geniculate nucleus (LGNd) to grating stimuli. Normal cats, as well as cats in which visual cortex was ablated, were studied. Adaptation was investigated using repeated presentation of gratings of different contrasts and orientations. The results showed the following: (1) Grating adaptation reduced the responses of 46% of the LGNd cells recorded. The responses normally decreased within 30 s and then stabilized. However, there was heterogeneity in the effects observed. About 38% of the cells studied were not affected by the adapting gratings. Some cells (16%) showed facilitation rather than habituation of their responses to test stimuli. (2) There was no significant difference between X and Y cells in their susceptibility to adaptation. This suggests that grating adaptation is a general property, independent of cell type. (3) The contrast-response curves of 57% of the LGNd cells studied shifted down after exposure to high-contrast adapting gratings. (4) Adapting gratings of the cells' preferred orientation decreased the orientation sensitivity of 56% of the orientation-sensitive cells. Adapting gratings at the nonpreferred orientation did not affect orientation sensitivity. (5) Prolonged grating adaptation also reduced the responses of 49% of the LGNd cells after inactivation of cortical inputs to the LGNd. PMID:8870219

  15. Visual motion aftereffects arise from a cascade of two isomorphic adaptation mechanisms

    PubMed Central

    Stocker, Alan A.; Simoncelli, Eero P.

    2013-01-01

    Prolonged exposure to a moving stimulus can substantially alter the perceived velocity (both speed and direction) of subsequently presented stimuli. Here, we show that these changes can be parsimoniously explained with a model that combines the effects of two isomorphic adaptation mechanisms, one nondirectional and one directional. Each produces a pattern of velocity biases that serves as an observable “signature” of the corresponding mechanism. The net effect on perceived velocity is a superposition of these two signatures. By examining human velocity judgments in the context of different adaptor velocities, we are able to separate these two signatures. The model fits the data well, successfully predicts subjects’ behavior in an additional experiment using a nondirectional adaptor, and is in agreement with a variety of previous experimental results. As such, the model provides a unifying explanation for the diversity of motion aftereffects. PMID:19761342

  16. Characterization of extracellular vesicles in whole blood: Influence of pre-analytical parameters and visualization of vesicle-cell interactions using imaging flow cytometry.

    PubMed

    Fendl, Birgit; Weiss, René; Fischer, Michael B; Spittler, Andreas; Weber, Viktoria

    2016-09-01

    Extracellular vesicles are central players in intercellular communication and are released from the plasma membrane under tightly regulated conditions, depending on the physiological and pathophysiological state of the producing cell. Their heterogeneity requires a spectrum of methods for isolation and characterization, where pre-analytical parameters have profound impact on vesicle analysis, particularly in blood, since sampling, addition of anticoagulants, as well as post-sampling vesicle generation may influence the outcome. Here, we characterized microvesicles directly in whole blood using a combination of flow cytometry and imaging flow cytometry. We assessed the influence of sample agitation, anticoagulation, and temperature on post-sampling vesicle generation, and show that vesicle counts remained stable over time in samples stored without agitation. Storage with gentle rolling mimicking agitation, in contrast, resulted in strong release of platelet-derived vesicles in blood anticoagulated with citrate or heparin, whereas vesicle counts remained stable upon anticoagulation with EDTA. Using imaging flow cytometry, we could visualize microvesicles adhering to blood cells and revealed an anticoagulant-dependent increase in vesicle-cell aggregates over time. We demonstrate that vesicles adhere preferentially to monocytes and granulocytes in whole blood, while no microvesicles could be visualized on lymphocytes. Our data underscore the relevance of pre-analytical parameters in vesicle analysis and demonstrate that imaging flow cytometry is a suitable tool to study the interaction of extracellular vesicles with their target cells. PMID:27444383

  17. Water Management Adaptations for Aquatic Ecosystem Services Under a Changing Climate. Analytical Framework and Case Study for Chinook Salmon in California

    NASA Astrophysics Data System (ADS)

    Escobar, M.; Mosser, C. M.; Thompson, L. C.; Purkey, D.; Moyle, P. B.

    2010-12-01

    Spring-run Chinook salmon (Oncorhynchus tshawytscha) are vulnerable to climate change because, before spawning in autumn, adults hold in river pools where temperature increases during summer. As these species naturally experience temperatures close to tolerable thresholds, climate-induced flow and temperature changes can increase their vulnerability. Our objective was to assemble an analytical framework to assess temperature and streamflow thresholds that would lead to critical reductions in spring-run Chinook salmon abundance, and to evaluate management adaptations to ameliorate these impacts. The analytical framework coupled climate data with watershed hydrology and salmon population dynamics models. We used WEAP, an integrated watershed hydrology, water management, and temperature model; and SALMOD, a spatially explicit and size/stage structured model that predicts population dynamics of salmon in freshwater systems. The models simulated weekly mean streamflow, temperature, and salmon abundance in Butte Creek, California. We calibrated and validated the models to adequately fit historical data. With the analytical framework built, we used bias-corrected and spatially downscaled climate data from six General Circulation Models and two emission scenarios for the period 2010 - 2099 to run the two linked models, and generated a range of potential future outcomes. WEAP predicted that summer base flows were lower, and water temperatures were higher for climate scenarios vs. historical conditions. SALMOD predicted increased summer thermal mortality of adult salmon; the population was predicted to decline for all climate scenarios and model combinations. We tested management adaptations, including cessation of water diverted for power production, and storage of cold reservoir water upstream for release during hot weather. Some adaptations resulted in cooler temperatures, more adults surviving to spawn, and extended population survival time. The coupled models, together

  18. Trained Eyes: Experience Promotes Adaptive Gaze Control in Dynamic and Uncertain Visual Environments

    PubMed Central

    Taya, Shuichiro; Windridge, David; Osman, Magda

    2013-01-01

    Current eye-tracking research suggests that our eyes make anticipatory movements to a location that is relevant for a forthcoming task. Moreover, there is evidence to suggest that with more practice anticipatory gaze control can improve. However, these findings are largely limited to situations where participants are actively engaged in a task. We ask: does experience modulate anticipative gaze control while passively observing a visual scene? To tackle this we tested people with varying degrees of experience of tennis, in order to uncover potential associations between experience and eye movement behaviour while they watched tennis videos. The number, size, and accuracy of saccades (rapid eye-movements) made around ‘events,’ which is critical for the scene context (i.e. hit and bounce) were analysed. Overall, we found that experience improved anticipatory eye-movements while watching tennis clips. In general, those with extensive experience showed greater accuracy of saccades to upcoming event locations; this was particularly prevalent for events in the scene that carried high uncertainty (i.e. ball bounces). The results indicate that, even when passively observing, our gaze control system utilizes prior relevant knowledge in order to anticipate upcoming uncertain event locations. PMID:23951147

  19. Manipulation of visual biofeedback during gait with a time delayed adaptive Virtual Mirror Box

    PubMed Central

    2014-01-01

    Background A mirror placed in the mid-sagittal plane of the body has been used to reduce phantom limb pain and improve movement function in medical conditions characterised by asymmetrical movement control. The mirrored illusion of unimpaired limb movement during gait might enhance the effect, but a physical mirror is only capable of showing parallel movement of limbs in real time typically while sitting. We aimed to overcome the limitations of physical mirrors by developing and evaluating a Virtual Mirror Box which delays the mirrored image of limbs during gait to ensure temporal congruency with the impaired physical limb. Methods An application was developed in the CAREN system’s D-Flow software which mirrors selected limbs recorded by real-time motion capture to the contralateral side. To achieve phase shifted movement of limbs during gait, the mirrored virtual limbs are also delayed by a continuously calculated amount derived from past gait events. In order to accommodate non-normal proportions and offsets of pathological gait, the movements are morphed so that the physical and virtual contact events match on the mirrored side. Our method was tested with a trans-femoral amputee walking on a treadmill using his artificial limb. Joint angles of the elbow and knee were compared between the intact and mirrored side using cross correlation, root mean squared difference and correlation coefficients. Results The time delayed adaptive virtual mirror box produced a symmetrical looking gait of the avatar coupled with a reduction of the difference between the intact and virtual knee and elbow angles (10.86° and 5.34° reduced to 4.99° and 2.54° respectively). Dynamic morphing of the delay caused a non-significant change of toe-off events when compared to delaying by 50% of the previous gait cycle, as opposed to the initial contact events which showed a practically negligible but statistically significant increase (p < 0.05). Conclusions Adding an adaptive time

  20. Analytic first derivatives for a spin-adapted open-shell coupled cluster theory: Evaluation of first-order electrical properties

    SciTech Connect

    Datta, Dipayan Gauss, Jürgen

    2014-09-14

    An analytic scheme is presented for the evaluation of first derivatives of the energy for a unitary group based spin-adapted coupled cluster (CC) theory, namely, the combinatoric open-shell CC (COSCC) approach within the singles and doubles approximation. The widely used Lagrange multiplier approach is employed for the derivation of an analytical expression for the first derivative of the energy, which in combination with the well-established density-matrix formulation, is used for the computation of first-order electrical properties. Derivations of the spin-adapted lambda equations for determining the Lagrange multipliers and the expressions for the spin-free effective density matrices for the COSCC approach are presented. Orbital-relaxation effects due to the electric-field perturbation are treated via the Z-vector technique. We present calculations of the dipole moments for a number of doublet radicals in their ground states using restricted open-shell Hartree-Fock (ROHF) and quasi-restricted HF (QRHF) orbitals in order to demonstrate the applicability of our analytic scheme for computing energy derivatives. We also report calculations of the chlorine electric-field gradients and nuclear quadrupole-coupling constants for the CCl, CH{sub 2}Cl, ClO{sub 2}, and SiCl radicals.

  1. Radar chart array analysis to visualize effects of formulation variables on IgG1 particle formation as measured by multiple analytical techniques.

    PubMed

    Kalonia, Cavan; Kumru, Ozan S; Kim, Jae Hyun; Middaugh, C Russell; Volkin, David B

    2013-12-01

    This study presents a novel method to visualize protein aggregate and particle formation data to rapidly evaluate the effect of solution and stress conditions on the physical stability of an immunoglobulin G (IgG) 1 monoclonal antibody (mAb). Radar chart arrays were designed so that hundreds of microflow digital imaging (MFI) solution measurements, evaluating different mAb formulations under varying stresses, could be presented in a single figure with minimal loss of data resolution. These MFI radar charts show measured changes in subvisible particle number, size, and morphology distribution as a change in the shape of polygons. Radar charts were also created to visualize mAb aggregate and particle formation across a wide size range by combining data sets from size-exclusion chromatography, Archimedes resonant mass measurements, and MFI. We found that the environmental/mechanical stress condition (e.g., heat vs. agitation) was the most important factor in influencing the particle size and morphology distribution with this IgG1 mAb. Additionally, the presence of NaCl exhibited a pH and stress-dependent behavior resulting in promotion or inhibition mAb particle formation. This data visualization technique provides a comprehensive analysis of the aggregation tendencies of this IgG1 mAb in different formulations with varying stresses as measured by different analytical techniques. PMID:24122556

  2. Radar chart array analysis to visualize effects of formulation variables on IgG1 particle formation as measured by multiple analytical techniques.

    PubMed

    Kalonia, Cavan; Kumru, Ozan S; Kim, Jae Hyun; Middaugh, C Russell; Volkin, David B

    2013-12-01

    This study presents a novel method to visualize protein aggregate and particle formation data to rapidly evaluate the effect of solution and stress conditions on the physical stability of an immunoglobulin G (IgG) 1 monoclonal antibody (mAb). Radar chart arrays were designed so that hundreds of microflow digital imaging (MFI) solution measurements, evaluating different mAb formulations under varying stresses, could be presented in a single figure with minimal loss of data resolution. These MFI radar charts show measured changes in subvisible particle number, size, and morphology distribution as a change in the shape of polygons. Radar charts were also created to visualize mAb aggregate and particle formation across a wide size range by combining data sets from size-exclusion chromatography, Archimedes resonant mass measurements, and MFI. We found that the environmental/mechanical stress condition (e.g., heat vs. agitation) was the most important factor in influencing the particle size and morphology distribution with this IgG1 mAb. Additionally, the presence of NaCl exhibited a pH and stress-dependent behavior resulting in promotion or inhibition mAb particle formation. This data visualization technique provides a comprehensive analysis of the aggregation tendencies of this IgG1 mAb in different formulations with varying stresses as measured by different analytical techniques.

  3. Application of radar chart array analysis to visualize effects of formulation variables on IgG1 particle formation as measured by multiple analytical techniques

    PubMed Central

    Kalonia, Cavan; Kumru, Ozan S.; Kim, Jae Hyun; Middaugh, C. Russell; Volkin, David B.

    2013-01-01

    This study presents a novel method to visualize protein aggregate and particle formation data to rapidly evaluate the effect of solution and stress conditions on the physical stability of an IgG1 monoclonal antibody (mAb). Radar chart arrays were designed so that hundreds of Microflow Digital Imaging (MFI) solution measurements, evaluating different mAb formulations under varying stresses, could be presented in a single figure with minimal loss of data resolution. These MFI radar charts show measured changes in subvisible particle number, size and morphology distribution as a change in the shape of polygons. Radar charts were also created to visualize mAb aggregate and particle formation across a wide size range by combining data sets from size exclusion chromatography (SEC), Archimedes resonant mass measurements, and MFI. We found that the environmental/mechanical stress condition (e.g., heat vs. agitation) was the most important factor in influencing the particle size and morphology distribution with this IgG1 mAb. Additionally, the presence of NaCl exhibited a pH and stress dependent behavior resulting in promotion or inhibition mAb particle formation. This data visualization technique provides a comprehensive analysis of the aggregation tendencies of this IgG1 mAb in different formulations with varying stresses as measured by different analytical techniques. PMID:24122556

  4. Out of the blue: adaptive visual pigment evolution accompanies Amazon invasion.

    PubMed

    Van Nynatten, Alexander; Bloom, Devin; Chang, Belinda S W; Lovejoy, Nathan R

    2015-07-01

    Incursions of marine water into South America during the Miocene prompted colonization of freshwater habitats by ancestrally marine species and present a unique opportunity to study the molecular evolution of adaptations to varying environments. Freshwater and marine environments are distinct in both spectra and average intensities of available light. Here, we investigate the molecular evolution of rhodopsin, the photosensitive pigment in the eye that activates in response to light, in a clade of South American freshwater anchovies derived from a marine ancestral lineage. Using likelihood-based comparative sequence analyses, we found evidence for positive selection in the rhodopsin of freshwater anchovy lineages at sites known to be important for aspects of rhodopsin function such as spectral tuning. No evidence was found for positive selection in marine lineages, nor in three other genes not involved in vision. Our results suggest that an increased rate of rhodopsin evolution was driven by diversification into freshwater habitats, thereby constituting a rare example of molecular evolution mirroring large-scale palaeogeographic events. PMID:26224386

  5. Separate channels for processing form, texture, and color: evidence from FMRI adaptation and visual object agnosia.

    PubMed

    Cavina-Pratesi, C; Kentridge, R W; Heywood, C A; Milner, A D

    2010-10-01

    Previous neuroimaging research suggests that although object shape is analyzed in the lateral occipital cortex, surface properties of objects, such as color and texture, are dealt with in more medial areas, close to the collateral sulcus (CoS). The present study sought to determine whether there is a single medial region concerned with surface properties in general or whether instead there are multiple foci independently extracting different surface properties. We used stimuli varying in their shape, texture, or color, and tested healthy participants and 2 object-agnosic patients, in both a discrimination task and a functional MR adaptation paradigm. We found a double dissociation between medial and lateral occipitotemporal cortices in processing surface (texture or color) versus geometric (shape) properties, respectively. In Experiment 2, we found that the medial occipitotemporal cortex houses separate foci for color (within anterior CoS and lingual gyrus) and texture (caudally within posterior CoS). In addition, we found that areas selective for shape, texture, and color individually were quite distinct from those that respond to all of these features together (shape and texture and color). These latter areas appear to correspond to those associated with the perception of complex stimuli such as faces and places.

  6. Behavioral Regulation, Visual Spatial Maturity in Kindergarten, and the Relationship of School Adaptation in the First Grade for a Sample of Turkish Children.

    PubMed

    Özer, Serap

    2016-04-01

    Behavioral regulation has recently become an important variable in research looking at kindergarten and first-grade achievement of children in private and public schools. The purpose of this study was to examine a measure of behavioral regulation, the Head Toes Knees Shoulders Task, and to evaluate its relationship with visual spatial maturity at the end of kindergarten. Later, in first grade, teachers were asked to rate the children (N = 82) in terms of academic and behavioral adaptation. Behavioral regulation and visual spatial maturity were significantly different between the two school types, but ratings by the teachers in the first grade were affected by children's visual spatial maturity rather than by behavioral regulation. Socioeducational opportunities provided by the two types of schools may be more important to school adaptation than behavioral regulation.

  7. Behavioral Regulation, Visual Spatial Maturity in Kindergarten, and the Relationship of School Adaptation in the First Grade for a Sample of Turkish Children.

    PubMed

    Özer, Serap

    2016-04-01

    Behavioral regulation has recently become an important variable in research looking at kindergarten and first-grade achievement of children in private and public schools. The purpose of this study was to examine a measure of behavioral regulation, the Head Toes Knees Shoulders Task, and to evaluate its relationship with visual spatial maturity at the end of kindergarten. Later, in first grade, teachers were asked to rate the children (N = 82) in terms of academic and behavioral adaptation. Behavioral regulation and visual spatial maturity were significantly different between the two school types, but ratings by the teachers in the first grade were affected by children's visual spatial maturity rather than by behavioral regulation. Socioeducational opportunities provided by the two types of schools may be more important to school adaptation than behavioral regulation. PMID:27154368

  8. A visual identification key utilizing both gestalt and analytic approaches to identification of Carices present in North America (Plantae, Cyperaceae).

    PubMed

    Jones, Timothy Mark

    2013-01-01

    Images are a critical part of the identification process because they enable direct, immediate and relatively unmediated comparisons between a specimen being identified and one or more reference specimens. The Carices Interactive Visual Identification Key (CIVIK) is a novel tool for identification of North American Carex species, the largest vascular plant genus in North America, and two less numerous closely-related genera, Cymophyllus and Kobresia. CIVIK incorporates 1288 high-resolution tiled image sets that allow users to zoom in to view minute structures that are crucial at times for identification in these genera. Morphological data are derived from the earlier Carex Interactive Identification Key (CIIK) which in turn used data from the Flora of North America treatments. In this new iteration, images can be viewed in a grid or histogram format, allowing multiple representations of data. In both formats the images are fully zoomable.

  9. A visual identification key utilizing both gestalt and analytic approaches to identification of Carices present in North America (Plantae, Cyperaceae)

    PubMed Central

    2013-01-01

    Abstract Images are a critical part of the identification process because they enable direct, immediate and relatively unmediated comparisons between a specimen being identified and one or more reference specimens. The Carices Interactive Visual Identification Key (CIVIK) is a novel tool for identification of North American Carex species, the largest vascular plant genus in North America, and two less numerous closely-related genera, Cymophyllus and Kobresia. CIVIK incorporates 1288 high-resolution tiled image sets that allow users to zoom in to view minute structures that are crucial at times for identification in these genera. Morphological data are derived from the earlier Carex Interactive Identification Key (CIIK) which in turn used data from the Flora of North America treatments. In this new iteration, images can be viewed in a grid or histogram format, allowing multiple representations of data. In both formats the images are fully zoomable. PMID:24723777

  10. An indirect adaptive neural control of a visual-based quadrotor robot for pursuing a moving target.

    PubMed

    Shirzadeh, Masoud; Amirkhani, Abdollah; Jalali, Aliakbar; Mosavi, Mohammad R

    2015-11-01

    This paper aims to use a visual-based control mechanism to control a quadrotor type aerial robot which is in pursuit of a moving target. The nonlinear nature of a quadrotor, on the one hand, and the difficulty of obtaining an exact model for it, on the other hand, constitute two serious challenges in designing a controller for this UAV. A potential solution for such problems is the use of intelligent control methods such as those that rely on artificial neural networks and other similar approaches. In addition to the two mentioned problems, another problem that emerges due to the moving nature of a target is the uncertainty that exists in the target image. By employing an artificial neural network with a Radial Basis Function (RBF) an indirect adaptive neural controller has been designed for a quadrotor robot in search of a moving target. The results of the simulation for different paths show that the quadrotor has efficiently tracked the moving target. PMID:26521725

  11. Visual Scanning Training, Limb Activation Treatment, and Prism Adaptation for Rehabilitating Left Neglect: Who is the Winner?

    PubMed Central

    Priftis, Konstantinos; Passarini, Laura; Pilosio, Cristina; Meneghello, Francesca; Pitteri, Marco

    2013-01-01

    We compared, for the first time, the overall and differential effects of three of the most widely used left neglect (LN) treatments: visual scanning training (VST), limb activation treatment (LAT), and prism adaptation (PA). Thirty-three LN patients were assigned in quasi-random order to the three groups (VST, LAT, or PA). Each patient received only one type of treatment. LN patients’ performance on everyday life tasks was assessed four times (over a period of 6 weeks): A1 and A2 (i.e., the two pre-treatment assessments); A3 and A4 (i.e., the two post-treatment assessments). LN patients in each of the three treatment conditions were treated for the same number of sessions (i.e., 20). The results showed that improvements were present in the majority of the tests assessing the peripersonal space in everyday life activities. Our findings were independent of unspecific factors and lasted for at least 2 weeks following the end of the treatments. There were no interactions, however, between LN treatments and assessments. We suggest that all three treatments can be considered as valid rehabilitation interventions for LN and could be employed for ameliorating LN signs. PMID:23847520

  12. Simulation of tumor induced angiogenesis using an analytical adaptive modeling including dynamic sprouting and blood flow modeling.

    PubMed

    Naghavi, Nadia; Hosseini, Farideh S; Sardarabadi, Mohammad; Kalani, Hadi

    2016-09-01

    In this paper, an adaptive model for tumor induced angiogenesis is developed that integrates generation and diffusion of a growth factor originated from hypoxic cells, adaptive sprouting from a parent vessel, blood flow and structural adaptation. The proposed adaptive sprout spacing model (ASS) determines position, time and number of sprouts which are activated from a parent vessel and also the developed vascular network is modified by a novel sprout branching prediction algorithm. This algorithm couples local vascular endothelial growth factor (VEGF) concentrations, stresses due to the blood flow and stochastic branching to the structural reactions of each vessel segment in response to mechanical and biochemical stimuli. The results provide predictions for the time-dependent development of the network structure, including the position and diameters of each segment and the resulting distributions of blood flow and VEGF. Considering time delays between sprout progressions and number of sprouts activated at different time durations provides information about micro-vessel density in the network. Resulting insights could be useful for motivating experimental investigations of vascular pattern in tumor induced angiogenesis and development of therapies targeting angiogenesis. PMID:27179697

  13. Microfluidic Distance Readout Sweet Hydrogel Integrated Paper-Based Analytical Device (μDiSH-PAD) for Visual Quantitative Point-of-Care Testing.

    PubMed

    Wei, Xiaofeng; Tian, Tian; Jia, Shasha; Zhu, Zhi; Ma, Yanli; Sun, Jianjun; Lin, Zhenyu; Yang, Chaoyong James

    2016-02-16

    A disposable, equipment-free, versatile point-of-care testing platform, microfluidic distance readout sweet hydrogel integrated paper-based analytical device (μDiSH-PAD), was developed for portable quantitative detection of different types of targets. The platform relies on a target-responsive aptamer cross-linked hydrogel for target recognition, cascade enzymatic reactions for signal amplification, and microfluidic paper-based analytic devices (μPADs) for visual distance-based quantitative readout. A "sweet" hydrogel with trapped glucoamylase (GA) was synthesized using an aptamer as a cross-linker. When target is present in the sample, the "sweet" hydrogel collapses and releases enzyme GA into the sample, generating glucose by amylolysis. A hydrophilic channel on the μPADs is modified with glucose oxidase (GOx) and colorless 3,3'-diaminobenzidine (DAB) as the substrate. When glucose travels along the channel by capillary action, it is converted to H2O2 by GOx. In addition, DAB is converted into brown insoluble poly-3,3'-diaminobenzidine [poly(DAB)] by horseradish peroxidase, producing a visible brown bar, whose length is positively correlated to the concentration of targets. The distance-based visual quantitative platform can detect cocaine in urine with high selectivity, sensitivity, and accuracy. Because the target-induced cascade reaction is triggered by aptamer/target recognition, this method is widely suitable for different kinds of targets. With the advantages of low cost, ease of operation, general applicability, and disposability with quantitative readout, the μDiSH-PAD holds great potential for portable detection of trace targets in environmental monitoring, security inspection, personalized healthcare, and clinical diagnostics. PMID:26765320

  14. Processing of Visual Imagery by an Adaptive Model of the Visual System: Its Performance and its Significance. Final Report, June 1969-March 1970.

    ERIC Educational Resources Information Center

    Tallman, Oliver H.

    A digital simulation of a model for the processing of visual images is derived from known aspects of the human visual system. The fundamental principle of computation suggested by a biological model is a transformation that distributes information contained in an input stimulus everywhere in a transform domain. Each sensory input contributes under…

  15. A multilevel analytical approach for detection and visualization of intracellular NO production and nitrosation events using diaminofluoresceins.

    PubMed

    Cortese-Krott, Miriam M; Rodriguez-Mateos, Ana; Kuhnle, Gunter G C; Brown, Geoff; Feelisch, Martin; Kelm, Malte

    2012-12-01

    Diaminofluoresceins are widely used probes for detection and intracellular localization of NO formation in cultured/isolated cells and intact tissues. The fluorinated derivative 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) has gained increasing popularity in recent years because of its improved NO sensitivity, pH stability, and resistance to photobleaching compared to the first-generation compound, DAF-2. Detection of NO production by either reagent relies on conversion of the parent compound into a fluorescent triazole, DAF-FM-T and DAF-2-T, respectively. Although this reaction is specific for NO and/or reactive nitrosating species, it is also affected by the presence of oxidants/antioxidants. Moreover, the reaction with other molecules can lead to the formation of fluorescent products other than the expected triazole. Thus additional controls and structural confirmation of the reaction products are essential. Using human red blood cells as an exemplary cellular system we here describe robust protocols for the analysis of intracellular DAF-FM-T formation using an array of fluorescence-based methods (laser-scanning fluorescence microscopy, flow cytometry, and fluorimetry) and analytical separation techniques (reversed-phase HPLC and LC-MS/MS). When used in combination, these assays afford unequivocal identification of the fluorescent signal as being derived from NO and are applicable to most other cellular systems without or with only minor modifications.

  16. Analytical approximations of the firing rate of an adaptive exponential integrate-and-fire neuron in the presence of synaptic noise

    PubMed Central

    Hertäg, Loreen; Durstewitz, Daniel; Brunel, Nicolas

    2014-01-01

    Computational models offer a unique tool for understanding the network-dynamical mechanisms which mediate between physiological and biophysical properties, and behavioral function. A traditional challenge in computational neuroscience is, however, that simple neuronal models which can be studied analytically fail to reproduce the diversity of electrophysiological behaviors seen in real neurons, while detailed neuronal models which do reproduce such diversity are intractable analytically and computationally expensive. A number of intermediate models have been proposed whose aim is to capture the diversity of firing behaviors and spike times of real neurons while entailing the simplest possible mathematical description. One such model is the exponential integrate-and-fire neuron with spike rate adaptation (aEIF) which consists of two differential equations for the membrane potential (V) and an adaptation current (w). Despite its simplicity, it can reproduce a wide variety of physiologically observed spiking patterns, can be fit to physiological recordings quantitatively, and, once done so, is able to predict spike times on traces not used for model fitting. Here we compute the steady-state firing rate of aEIF in the presence of Gaussian synaptic noise, using two approaches. The first approach is based on the 2-dimensional Fokker-Planck equation that describes the (V,w)-probability distribution, which is solved using an expansion in the ratio between the time constants of the two variables. The second is based on the firing rate of the EIF model, which is averaged over the distribution of the w variable. These analytically derived closed-form expressions were tested on simulations from a large variety of model cells quantitatively fitted to in vitro electrophysiological recordings from pyramidal cells and interneurons. Theoretical predictions closely agreed with the firing rate of the simulated cells fed with in-vivo-like synaptic noise. PMID:25278872

  17. The Role of the Human Extrastriate Visual Cortex in Mirror Symmetry Discrimination: A TMS-Adaptation Study

    ERIC Educational Resources Information Center

    Cattaneo, Zaira; Mattavelli, Giulia; Papagno, Costanza; Herbert, Andrew; Silvanto, Juha

    2011-01-01

    The human visual system is able to efficiently extract symmetry information from the visual environment. Prior neuroimaging evidence has revealed symmetry-preferring neuronal representations in the dorsolateral extrastriate visual cortex; the objective of the present study was to investigate the necessity of these representations in symmetry…

  18. Dynamic 3D visual analytic tools: a method for maintaining situational awareness during high tempo warfare or mass casualty operations

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2010-04-01

    Maintaining Situational Awareness (SA) is crucial to the success of high tempo operations, such as war fighting and mass casualty events (bioterrorism, natural disasters). Modern computer and software applications attempt to provide command and control manager's situational awareness via the collection, integration, interrogation and display of vast amounts of analytic data in real-time from a multitude of data sources and formats [1]. At what point does the data volume and displays begin to erode the hierarchical distributive intelligence, command and control structure of the operation taking place? In many cases, people tasked with making decisions, have insufficient experience in SA of high tempo operations and become overwhelmed easily as vast amounts of data begin to be displayed in real-time as an operation unfolds. In these situations, where data is plentiful and the relevance of the data changes rapidly, there is a chance for individuals to target fixate on those data sources they are most familiar. If these individuals fall into this type of pitfall, they will exclude other data that might be just as important to the success of the operation. To counter these issues, it is important that the computer and software applications provide a means for prompting its users to take notice of adverse conditions or trends that are critical to the operation. This paper will discuss a new method of displaying data called a Crisis ViewTM, that monitors critical variables that are dynamically changing and allows preset thresholds to be created to prompt the user when decisions need to be made and when adverse or positive trends are detected. The new method will be explained in basic terms, with examples of its attributes and how it can be implemented.

  19. Characterization of particulate matter deposited in diesel particulate filters: Visual and analytical approach in macro-, micro- and nano-scales

    SciTech Connect

    Liati, Anthi; Dimopoulos Eggenschwiler, Panayotis

    2010-09-15

    Multi-scale analytical investigations of particulate matter (soot and ash) of two loaded diesel particulate filters (DPF) from (a) a truck (DPF1) and (b) a passenger car (DPF2) reveal the following: in DPF1 (without fuel-borne additives), soot aggregates form an approximately 130-270 {mu}m thick, homogeneous porous cake with pronounced orientation. Soot aggregates consist of 15-30 nm large individual particles exhibiting relatively mature internal nanostructures, however, far from being graphite. Ash aggregates largely accumulate at the outlet part of DPF1, while minor amounts are deposited directly on the channel walls all along the filter length. They consist of crystalline phases with individual particles of sizes down to the nanoscale range. Chemically, the ash consists mainly of Mg, S, Ca, Zn and P, elements encountered in lubricating oil additives. In the passenger car DPF2 (with fuel-borne additives), soot aggregates form an approximately 200-500 {mu}m thick, inhomogeneous porous cake consisting of several superposed layers corresponding to different soot generations. The largest part of the soot cake is composed of unburned, oriented soot aggregates left behind despite repeated regenerations, while a small part constitutes a loose layer with randomly oriented aggregates, which was deposited last and has not seen any regeneration. Fe-oxide particles of micro- to nano-scale sizes, originating from the fuel-borne additive, are often dispersed within the part of the soot cake composed of the unburned soot leftovers. The individual soot nanoparticles in DPF2 are approximately 15-40 nm large and generally less mature than in the truck DPF1. The presence of soot leftovers in DPF2 indicates that the addition of fuel-borne material does not fully compensate for the temperatures needed for complete soot removal. Ash in DPF2 is filling up more than half of the filter volume (at the downstream part) and is dominated by Fe-oxide aggregates, due to the Fe-based fuel

  20. Impact of Adaptive Materials on Teachers and Their Students with Visual Impairments in Secondary Science and Mathematics Classes

    ERIC Educational Resources Information Center

    Rule, Audrey C.; Stefanich, Greg P.; Boody, Robert M.; Peiffer, Belinda

    2011-01-01

    Science, technology, engineering, and mathematics (STEM) fields, important in today's world, are underrepresented by students with disabilities. Students with visual impairments, although cognitively similar to sighted peers, face challenges as STEM subjects are often taught using visuals. They need alternative forms of access such as enlarged or…

  1. Prism adaptation aftereffects in stroke patients with spatial neglect: Pathological effects on subjective straight ahead but not visual open-loop pointing

    PubMed Central

    Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Papps, Ben; Husain, Masud; Driver, Jon

    2008-01-01

    Prism adaptation to rightward optical shifts during visually guided pointing is considered a promising intervention in right-hemisphere stroke patients with left spatial neglect. Conventionally, prism adaptation is assessed via aftereffects, on subjective straight ahead (SSA) pointing with eyes closed; or by visual open-loop pointing (VOL), i.e. pointing to a visual target without seeing the hand. Previous data suggest indirectly that prism aftereffects in neglect patients may be larger (pathologically so) when assessed by SSA than by VOL. But these measures have never been directly compared within the same patients after identical prism exposure. Accordingly we implemented both measures here within the same group of 13 neglect patients and 13 controls. Prism aftereffects were much larger for SSA than VOL in neglect patients, falling outside the normative range only for SSA. This may arise because the SSA task can itself involve aspects of neglect that may be ameliorated by the prism intervention, hence showing abnormal changes after prisms. The extent of SSA change after prisms varied between patients, and correlated with improvements on a standard cancellation measure for neglect. The lesions of patients who did versus did not show neglect improvement immediately after prisms provide an initial indication that lack of improvement may potentially relate to cortical damage in right intraparietal sulcus and white matter damage in inferior parietal lobe and middle frontal gyrus. Future studies of possible rehabilitative impact from prisms upon neglect may need to consider carefully how to measure prism adaptation per se, separately from any impact of such adaptation upon manifestations of neglect. PMID:18083203

  2. Performance & Emotion--A Study on Adaptive E-Learning Based on Visual/Verbal Learning Styles

    ERIC Educational Resources Information Center

    Beckmann, Jennifer; Bertel, Sven; Zander, Steffi

    2015-01-01

    Adaptive e-Learning systems are able to adjust to a user's learning needs, usually by user modeling or tracking progress. Such learner-adaptive behavior has rapidly become a hot topic for e-Learning, furthered in part by the recent rapid increase in the use of MOOCs (Massive Open Online Courses). A lack of general, individual, and situational data…

  3. Analytical method development for powder characterization: Visualization of the critical drug loading affecting the processability of a formulation for direct compression.

    PubMed

    Hirschberg, Cosima; Sun, Changquan Calvin; Rantanen, Jukka

    2016-09-01

    Characterization of particulate systems (powders) is one of the remaining scientific challenges. Evaluation of powder behaviour is often empirical and the decision-making processes are experience-based. There is a need for development of analytical instrumentation enabling more fundamental understanding of powder behaviour. Flowability and tabletability, two key factors in commercial scale manufacturing of tablets with direct compression (DC) approach, were analysed for formulations containing increasing amounts of several model active pharmaceutical ingredients (APIs). Flowability was investigated using a ring shear tester and tablets were prepared at four different compression pressures using a single punch tablet press. Thereby, a material sparing screening approach was developed to estimate the influence of APIs on behaviour of a given DC formulation. Additionally, this approach is useful for estimating the low threshold amount of API (wt%), at which the properties of an API start affecting the powder behaviour of a given formulation (API-excipient mixture). This threshold will be referred to as critical drug loading. The flowability of microcrystalline cellulose (reference grade pH 102) was used as a threshold for adequate flowability of model formulations. The threshold for tablet tensile strength was set to 2MPa. Simultaneous visual presentation of both- flowability and tabletability were used for a fast evaluation of manufacturability of a given formulation. The results confirmed that flowability is more sensitive to drug loading than tabletability, and that the critical drug loading for a DC formulation is strongly affected by particulate properties of API. For example, decreasing the particle size of paracetamol led to rapid decrease in flowability index, whereas the tabletability was not affected. PMID:27368089

  4. Giving Raw Data a Chance to Talk: A Demonstration of Exploratory Visual Analytics with a Pediatric Research Database Using Microsoft Live Labs Pivot to Promote Cohort Discovery, Research, and Quality Assessment

    PubMed Central

    Viangteeravat, Teeradache; Nagisetty, Naga Satya V. Rao

    2014-01-01

    Secondary use of large and open data sets provides researchers with an opportunity to address high-impact questions that would otherwise be prohibitively expensive and time consuming to study. Despite the availability of data, generating hypotheses from huge data sets is often challenging, and the lack of complex analysis of data might lead to weak hypotheses. To overcome these issues and to assist researchers in building hypotheses from raw data, we are working on a visual and analytical platform called PRD Pivot. PRD Pivot is a de-identified pediatric research database designed to make secondary use of rich data sources, such as the electronic health record (EHR). The development of visual analytics using Microsoft Live Labs Pivot makes the process of data elaboration, information gathering, knowledge generation, and complex information exploration transparent to tool users and provides researchers with the ability to sort and filter by various criteria, which can lead to strong, novel hypotheses. PMID:24808811

  5. Giving raw data a chance to talk: a demonstration of exploratory visual analytics with a pediatric research database using Microsoft Live Labs Pivot to promote cohort discovery, research, and quality assessment.

    PubMed

    Viangteeravat, Teeradache; Nagisetty, Naga Satya V Rao

    2014-01-01

    Secondary use of large and open data sets provides researchers with an opportunity to address high-impact questions that would otherwise be prohibitively expensive and time consuming to study. Despite the availability of data, generating hypotheses from huge data sets is often challenging, and the lack of complex analysis of data might lead to weak hypotheses. To overcome these issues and to assist researchers in building hypotheses from raw data, we are working on a visual and analytical platform called PRD Pivot. PRD Pivot is a de-identified pediatric research database designed to make secondary use of rich data sources, such as the electronic health record (EHR). The development of visual analytics using Microsoft Live Labs Pivot makes the process of data elaboration, information gathering, knowledge generation, and complex information exploration transparent to tool users and provides researchers with the ability to sort and filter by various criteria, which can lead to strong, novel hypotheses.

  6. Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial

    PubMed Central

    Hollands, Kristen L.; Pelton, Trudy A.; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M.; Wing, Alan M.; Tyson, Sarah F.; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M.

    2015-01-01

    Objectives Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. Design This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services Participants Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments Intervention Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Results Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Conclusions Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Trial Registration Clinicaltrials.gov NCT01600391 PMID:26445137

  7. Interactions between concentric form-from-structure and face perception revealed by visual masking but not adaptation

    PubMed Central

    Feczko, Eric; Shulman, Gordon L.; Petersen, Steven E.; Pruett, John R.

    2014-01-01

    Findings from diverse subfields of vision research suggest a potential link between high-level aspects of face perception and concentric form-from-structure perception. To explore this relationship, typical adults performed two adaptation experiments and two masking experiments to test whether concentric, but not nonconcentric, Glass patterns (a type of form-from-structure stimulus) utilize a processing mechanism shared by face perception. For the adaptation experiments, subjects were presented with an adaptor for 5 or 20 s, prior to discriminating a target. In the masking experiments, subjects saw a mask, then a target, and then a second mask. Measures of discriminability and bias were derived and repeated measures analysis of variance tested for pattern-specific masking and adaptation effects. Results from Experiment 1 show no Glass pattern-specific effect of adaptation to faces; results from Experiment 2 show concentric Glass pattern masking, but not adaptation, may impair upright/inverted face discrimination; results from Experiment 3 show concentric and radial Glass pattern masking impaired subsequent upright/inverted face discrimination more than translational Glass pattern masking; and results from Experiment 4 show concentric and radial Glass pattern masking impaired subsequent face gender discrimination more than translational Glass pattern masking. Taken together, these findings demonstrate interactions between concentric form-from-structure and face processing, suggesting a possible common processing pathway. PMID:24563526

  8. Application of Non-Kolmogorovian Probability and Quantum Adaptive Dynamics to Unconscious Inference in Visual Perception Process

    NASA Astrophysics Data System (ADS)

    Accardi, Luigi; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro

    2016-07-01

    Recently a novel quantum information formalism — quantum adaptive dynamics — was developed and applied to modelling of information processing by bio-systems including cognitive phenomena: from molecular biology (glucose-lactose metabolism for E.coli bacteria, epigenetic evolution) to cognition, psychology. From the foundational point of view quantum adaptive dynamics describes mutual adapting of the information states of two interacting systems (physical or biological) as well as adapting of co-observations performed by the systems. In this paper we apply this formalism to model unconscious inference: the process of transition from sensation to perception. The paper combines theory and experiment. Statistical data collected in an experimental study on recognition of a particular ambiguous figure, the Schröder stairs, support the viability of the quantum(-like) model of unconscious inference including modelling of biases generated by rotation-contexts. From the probabilistic point of view, we study (for concrete experimental data) the problem of contextuality of probability, its dependence on experimental contexts. Mathematically contextuality leads to non-Komogorovness: probability distributions generated by various rotation contexts cannot be treated in the Kolmogorovian framework. At the same time they can be embedded in a “big Kolmogorov space” as conditional probabilities. However, such a Kolmogorov space has too complex structure and the operational quantum formalism in the form of quantum adaptive dynamics simplifies the modelling essentially.

  9. Adaptations and Continuities in the Use and Design of Visual Representations in US Middle School Science Textbooks

    ERIC Educational Resources Information Center

    Lee, Victor R.

    2010-01-01

    Visual representations are ubiquitous in modern-day science textbooks and have in recent years become an object of criticism and scrutiny. This article examines the extent to which changes in representations in textbooks published in the USA over the past six decades have invited those critiques. Drawing from a correlational analysis of a corpus…

  10. Creating an Adaptive Technology Using a Cheminformatics System to Read Aloud Chemical Compound Names for People with Visual Disabilities

    ERIC Educational Resources Information Center

    Kamijo, Haruo; Morii, Shingo; Yamaguchi, Wataru; Toyooka, Naoki; Tada-Umezaki, Masahito; Hirobayashi, Shigeki

    2016-01-01

    Various tactile methods, such as Braille, have been employed to enhance the recognition ability of chemical structures by individuals with visual disabilities. However, it is unknown whether reading aloud the names of chemical compounds would be effective in this regard. There are no systems currently available using an audio component to assist…

  11. Adaptation of a visualized loop-mediated isothermal amplification technique for field detection of Plasmodium vivax infection

    PubMed Central

    2011-01-01

    Background Loop-mediated isothermal amplification (LAMP) is a high performance method for detecting DNA and holds promise for use in the molecular detection of infectious pathogens, including Plasmodium spp. However, in most malaria-endemic areas, which are often resource-limited, current LAMP methods are not feasible for diagnosis due to difficulties in accurately interpreting results with problems of sensitive visualization of amplified products, and the risk of contamination resulting from the high quantity of amplified DNA produced. In this study, we establish a novel visualized LAMP method in a closed-tube system, and validate it for the diagnosis of malaria under simulated field conditions. Methods A visualized LAMP method was established by the addition of a microcrystalline wax-dye capsule containing the highly sensitive DNA fluorescence dye SYBR Green I to a normal LAMP reaction prior to the initiation of the reaction. A total of 89 blood samples were collected on filter paper and processed using a simple boiling method for DNA extraction, and then tested by the visualized LAMP method for Plasmodium vivax infection. Results The wax capsule remained intact during isothermal amplification, and released the DNA dye to the reaction mixture only when the temperature was raised to the melting point following amplification. Soon after cooling down, the solidified wax sealed the reaction mix at the bottom of the tube, thus minimizing the risk of aerosol contamination. Compared to microscopy, the sensitivity and specificity of LAMP were 98.3% (95% confidence interval (CI): 91.1-99.7%) and 100% (95% CI: 88.3-100%), and were in close agreement with a nested polymerase chain reaction method. Conclusions This novel, cheap and quick visualized LAMP method is feasible for malaria diagnosis in resource-limited field settings. PMID:21693031

  12. Experimental and Analytic Evaluation of the Effects of Visual and Motion Simulation in SH-3 Helicopter Training. Technical Report 85-002.

    ERIC Educational Resources Information Center

    Pfeiffer, Mark G.; Scott, Paul G.

    A fly-only group (N=16) of Navy replacement pilots undergoing fleet readiness training in the SH-3 helicopter was compared with groups pre-trained on Device 2F64C with: (1) visual only (N=13); (2) no visual/no motion (N=14); and (3) one visual plus motion group (N=19). Groups were compared for their SH-3 helicopter performance in the transition…

  13. Online Visual Feedback during Error-Free Channel Trials Leads to Active Unlearning of Movement Dynamics: Evidence for Adaptation to Trajectory Prediction Errors

    PubMed Central

    Lago-Rodriguez, Angel; Miall, R. Chris

    2016-01-01

    Prolonged exposure to movement perturbations leads to creation of motor memories which decay towards previous states when the perturbations are removed. However, it remains unclear whether this decay is due only to a spontaneous and passive recovery of the previous state. It has recently been reported that activation of reinforcement-based learning mechanisms delays the onset of the decay. This raises the question whether other motor learning mechanisms may also contribute to the retention and/or decay of the motor memory. Therefore, we aimed to test whether mechanisms of error-based motor adaptation are active during the decay of the motor memory. Forty-five right-handed participants performed point-to-point reaching movements under an external dynamic perturbation. We measured the expression of the motor memory through error-clamped (EC) trials, in which lateral forces constrained movements to a straight line towards the target. We found greater and faster decay of the motor memory for participants who had access to full online visual feedback during these EC trials (Cursor group), when compared with participants who had no EC feedback regarding movement trajectory (Arc group). Importantly, we did not find between-group differences in adaptation to the external perturbation. In addition, we found greater decay of the motor memory when we artificially increased feedback errors through the manipulation of visual feedback (Augmented-Error group). Our results then support the notion of an active decay of the motor memory, suggesting that adaptive mechanisms are involved in correcting for the mismatch between predicted movement trajectories and actual sensory feedback, which leads to greater and faster decay of the motor memory. PMID:27721748

  14. Interdisciplinary Collaboration in the Choice of an Adapted Mobility Device for a Child with Cerebral Palsy and Visual Impairment.

    ERIC Educational Resources Information Center

    Glanzman, Allan; Ducret, Walter

    2003-01-01

    To select an adapted mobility device for a 5-year-old boy with blindness and spastic diplegic cerebral palsy, a multidisciplinary team used 8-millimeter videography to evaluate the subject's joint angle during ambulation with one of three canes and with no cane. The I-style cane provided optimal posture and gait pattern. (Contains references.) (CR)

  15. Preliminary tests of a possible outdoor light adaptation solution for a fly inspired visual sensor: a biomimetic solution - biomed 2011.

    PubMed

    Dean, Brian K; Wright, Cameron H G; Barrett, Steven F

    2011-01-01

    Two previous papers, presented at RMBS in 2009 and 2010, introduced a fly inspired vision sensor that could adapt to indoor light conditions by mimicking the light adaptation process of the commonhousefly, Muscadomestica. A new system has been designed that should allow the sensor to adapt to outdoor light conditions which will enable the sensor’s use inapplications such as: unmanned aerial vehicle (UAV) obstacle avoidance, UAV landing support, target tracking, wheelchair guidance, large structure monitoring, and many other outdoor applications. A sensor of this type is especially suited for these applications due to features of hyperacuity (or an ability to achieve movement resolution beyond the theoretical limit), extreme sensitivity to motion, and (through software simulation) image edge extraction, motion detection, and orientation and location of a line.Many of these qualities are beyond the ability of traditional computervision sensors such as charge coupled device (CCD) arrays.To achieve outdoor light adaptation, a variety of design obstacles have to be overcome such as infrared interference, dynamic range expansion, and light saturation. The newly designed system overcomes the latter two design obstacles by mimicking the fly’s solution of logarithmic compression followed by removal of the average background light intensity. This paper presents the new design and the preliminary tests that were conducted to determine its effectiveness. PMID:21525612

  16. Psychosocial Adaptation to Visual Impairment and Its Relationship to Depressive Affect in Older Adults with Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Tolman, Jennifer; Hill, Robert D.; Kleinschmidt, Julia J.; Gregg, Charles H.

    2005-01-01

    Purpose: In this study we examined psychosocial adaptation to vision loss and its relationship to depressive symptomatology in legally blind older adults with age-related macular degeneration (ARMD). Design and Methods: The 144 study participants were outpatients of a large regional vision clinic that specializes in the diagnosis and treatment of…

  17. Preliminary tests of a possible outdoor light adaptation solution for a fly inspired visual sensor: a biomimetic solution - biomed 2011.

    PubMed

    Dean, Brian K; Wright, Cameron H G; Barrett, Steven F

    2011-01-01

    Two previous papers, presented at RMBS in 2009 and 2010, introduced a fly inspired vision sensor that could adapt to indoor light conditions by mimicking the light adaptation process of the commonhousefly, Muscadomestica. A new system has been designed that should allow the sensor to adapt to outdoor light conditions which will enable the sensor’s use inapplications such as: unmanned aerial vehicle (UAV) obstacle avoidance, UAV landing support, target tracking, wheelchair guidance, large structure monitoring, and many other outdoor applications. A sensor of this type is especially suited for these applications due to features of hyperacuity (or an ability to achieve movement resolution beyond the theoretical limit), extreme sensitivity to motion, and (through software simulation) image edge extraction, motion detection, and orientation and location of a line.Many of these qualities are beyond the ability of traditional computervision sensors such as charge coupled device (CCD) arrays.To achieve outdoor light adaptation, a variety of design obstacles have to be overcome such as infrared interference, dynamic range expansion, and light saturation. The newly designed system overcomes the latter two design obstacles by mimicking the fly’s solution of logarithmic compression followed by removal of the average background light intensity. This paper presents the new design and the preliminary tests that were conducted to determine its effectiveness.

  18. Sentence Syntax and Content in the Human Temporal Lobe: An fMRI Adaptation Study in Auditory and Visual Modalities

    ERIC Educational Resources Information Center

    Devauchelle, Anne-Dominique; Oppenheim, Catherine; Rizzi, Luigi; Dehaene, Stanislas; Pallier, Christophe

    2009-01-01

    Priming effects have been well documented in behavioral psycholinguistics experiments: The processing of a word or a sentence is typically facilitated when it shares lexico-semantic or syntactic features with a previously encountered stimulus. Here, we used fMRI priming to investigate which brain areas show adaptation to the repetition of a…

  19. Scientific Objectives and Design Study of an Adaptive Optics Visual Echelle Spectrograph and Imager Coronograph (AVES-IMCO) for the NAOS Visitor Focus at the VLT

    NASA Astrophysics Data System (ADS)

    Pallavicini, Roberto; Zerbi, Filippo; Beuzit, Jean-Luc; Bonanno, Giovanni; Bonifacio, Piercarlo; Comari, Maurizio; Conconi, Paolo; Delabre, Bernard; Franchini, Mariagrazia; Marcantonio, Paolo Di; Lagrange, Anne-Marie; Mazzoleni, Ruben; Molaro, Paolo; Pasquini, Luca; Santin, Paolo

    We present the scientific case for an Adaptive Optics Visual Echelle Spectrograph and Imager Coronograph (AVES-IMCO) that we propose as a visitor instrument for the secondary port of NAOS at the VLT. We show that such an instrument would be ideal for intermediate resolution (R=16,000) spectroscopy of faint sky-limited objects down to a magnitude of V=24.0 and will complement very effectively the near-IR imaging capabilities of CONICA. We present examples of science programmes that could be carried out with such an instrument and which cannot be addressed with existing VLT instruments. We also report on the result of a two-year design study of the instrument, with specific reference to its use as parallel instrument of NAOS.

  20. The PICS Climate Insights 101 Courses: A Visual Approach to Learning About Climate Science, Mitigation and Adaptation

    NASA Astrophysics Data System (ADS)

    Pedersen, T. F.; Zwiers, F. W.; Breen, C.; Murdock, T. Q.

    2014-12-01

    The Pacific Institute for Climate Solutions (PICS) has now made available online three free, peer-reviewed, unique animated short courses in a series entitled "Climate Insights 101" that respectively address basic climate science, carbon-emissions mitigation approaches and opportunities, and adaptation. The courses are suitable for students of all ages, and use professionally narrated animations designed to hold a viewer's attention. Multiple issues are covered, including complex concerns like the construction of general circulation models, carbon pricing schemes in various countries, and adaptation approaches in the face of extreme weather events. Clips will be shown in the presentation. The first course (Climate Science Basics) has now been seen by over two hundred thousand individuals in over 80 countries, despite being offered in English only. Each course takes about two hours to work through, and in recognizing that that duration might pose an attention barrier to some students, PICS selected a number of short clips from the climate-science course and posted them as independent snippets on YouTube. A companion series of YouTube videos entitled, "Clear The Air", was created to confront the major global-warming denier myths. But a major challenge remains: despite numerous efforts to promote the availability of the free courses and the shorter YouTube pieces, they have yet to become widely known. Strategies to overcome that constraint will be discussed.

  1. A Closed-loop Brain Computer Interface to a Virtual Reality Avatar: Gait Adaptation to Visual Kinematic Perturbations

    PubMed Central

    Luu, Trieu Phat; He, Yongtian; Brown, Samuel; Nakagome, Sho; Contreras-Vidal, Jose L.

    2016-01-01

    The control of human bipedal locomotion is of great interest to the field of lower-body brain computer interfaces (BCIs) for rehabilitation of gait. While the feasibility of a closed-loop BCI system for the control of a lower body exoskeleton has been recently shown, multi-day closed-loop neural decoding of human gait in a virtual reality (BCI-VR) environment has yet to be demonstrated. In this study, we propose a real-time closed-loop BCI that decodes lower limb joint angles from scalp electroencephalography (EEG) during treadmill walking to control the walking movements of a virtual avatar. Moreover, virtual kinematic perturbations resulting in asymmetric walking gait patterns of the avatar were also introduced to investigate gait adaptation using the closed-loop BCI-VR system over a period of eight days. Our results demonstrate the feasibility of using a closed-loop BCI to learn to control a walking avatar under normal and altered visuomotor perturbations, which involved cortical adaptations. These findings have implications for the development of BCI-VR systems for gait rehabilitation after stroke and for understanding cortical plasticity induced by a closed-loop BCI system. PMID:27713915

  2. The complex evolutionary history of seeing red: molecular phylogeny and the evolution of an adaptive visual system in deep-sea dragonfishes (Stomiiformes: Stomiidae).

    PubMed

    Kenaley, Christopher P; Devaney, Shannon C; Fjeran, Taylor T

    2014-04-01

    The vast majority of deep-sea fishes have retinas composed of only rod cells sensitive to only shortwave blue light, approximately 480-490 nm. A group of deep-sea dragonfishes, the loosejaws (family Stomiidae), possesses far-red emitting photophores and rhodopsins sensitive to long-wave emissions greater than 650 nm. In this study, the rhodopsin diversity within the Stomiidae is surveyed based on an analysis of rod opsin-coding sequences from representatives of 23 of the 28 genera. Using phylogenetic inference, fossil-calibrated estimates of divergence times, and a comparative approach scanning the stomiid phylogeny for shared genotypes and substitution histories, we explore the evolution and timing of spectral tuning in the family. Our results challenge both the monophyly of the family Stomiidae and the loosejaws. Despite paraphyly of the loosejaws, we infer for the first time that far-red visual systems have a single evolutionary origin within the family and that this shift in phenotype occurred at approximately 15.4 Ma. In addition, we found strong evidence that at approximately 11.2 Ma the most recent common ancestor of two dragonfish genera reverted to a primitive shortwave visual system during its evolution from a far-red sensitive dragonfish. According to branch-site tests for adaptive evolution, we hypothesize that positive selection may be driving spectral tuning in the Stomiidae. These results indicate that the evolutionary history of visual systems in deep-sea species is complex and a more thorough understanding of this system requires an integrative comparative approach.

  3. How information visualization novices construct visualizations.

    PubMed

    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.

  4. Luminance and opponent-color contributions to visual detection and adaptation and to temporal and spatial integration.

    PubMed

    King-Smith, P E; Carden, D

    1976-07-01

    We show how the processes of visual detection and of temporal and spatial summation may be analyzed in terms of parallel luminance (achromatic) and opponent-color systems; a test flash is detected if it exceeds the threshold of either system. The spectral sensitivity of the luminance system may be determined by a flicker method, and has a single broad peak near 555 nm; the spectral sensitivity of the opponent-color system corresponds to the color recognition threshold, and has three peaks at about 440, 530, and 600 nm (on a white background). The temporal and spatial integration of the opponent-color system are generally greater than for the luminance system; further, a white background selectively depresses the sensitivity of the luminance system relative to the opponent-color system. Thus relatively large (1 degree) and long (200 msec) spectral test flashes on a white background are detected by the opponent-color system except near 570 nm; the contribution of the luminance system becomes more prominent if the size or duration of the test flash is reduced, or if the white background is extinguished. The present analysis is discussed in relation to Stiles' model of independent eta mechanisms.

  5. Multiscale image fusion using an adaptive similarity-based sensor weighting scheme and human visual system-inspired contrast measure

    NASA Astrophysics Data System (ADS)

    Nercessian, Shahan C.; Panetta, Karen A.; Agaian, Sos S.

    2012-04-01

    The goal of image fusion is to combine multiple source images obtained using different capture techniques into a single image to provide an effective contextual enhancement of a scene for human or machine perception. In practice, considerable value can be gained in the fusion of images that are dissimilar or complementary in nature. However, in such cases, global weighting schemes may not sufficiently weigh the contribution of the pertinent information of the source images, while existing adaptive schemes calculate weights based on the relative amounts of salient features, which can cause severe artifacting or inadequate local luminance in the fusion result. Accordingly, a new multiscale image fusion algorithm is proposed. The approximation coefficient fusion rule of the algorithm is based on a novel similarity based weighting scheme capable of providing improved fusion results when the input source images are either similar or dissimilar to each other. Moreover, the algorithm employs a new detail coefficient fusion rule integrating a parametric multiscale contrast measure. The parametric nature of the contrast measure allows the degree to which psychophysical laws of human vision hold to be tuned based on image-dependent characteristics. Experimental results illustrate the superior performance of the proposed algorithm qualitatively and quantitatively.

  6. Visualization rhetoric: framing effects in narrative visualization.

    PubMed

    Hullman, Jessica; Diakopoulos, Nicholas

    2011-12-01

    Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation.

  7. Attention and visual memory in visualization and computer graphics.

    PubMed

    Healey, Christopher G; Enns, James T

    2012-07-01

    A fundamental goal of visualization is to produce images of data that support visual analysis, exploration, and discovery of novel insights. An important consideration during visualization design is the role of human visual perception. How we "see" details in an image can directly impact a viewer's efficiency and effectiveness. This paper surveys research on attention and visual perception, with a specific focus on results that have direct relevance to visualization and visual analytics. We discuss theories of low-level visual perception, then show how these findings form a foundation for more recent work on visual memory and visual attention. We conclude with a brief overview of how knowledge of visual attention and visual memory is being applied in visualization and graphics. We also discuss how challenges in visualization are motivating research in psychophysics.

  8. Visual/verbal-analytic reasoning bias as a function of self-reported autistic-like traits: a study of typically developing individuals solving Raven's Advanced Progressive Matrices.

    PubMed

    Fugard, Andrew J B; Stewart, Mary E; Stenning, Keith

    2011-05-01

    People with autism spectrum condition (ASC) perform well on Raven's matrices, a test which loads highly on the general factor in intelligence. However, the mechanisms supporting enhanced performance on the test are poorly understood. Evidence is accumulating that milder variants of the ASC phenotype are present in typically developing individuals, and that those who are further along the autistic-like trait spectrum show similar patterns of abilities and impairments as people with clinically diagnosed ASC. We investigated whether self-reported autistic-like traits in a university student sample, assessed using the Autism-Spectrum Quotient (AQ; Baron-Cohen, Wheelwright, Skinner, et al., 2001), predict performance on Raven's Advanced Progressive Matrices. We found that reporting poorer social skills but better attention switching predicted a higher Advanced matrices score overall. DeShon, Chan, and Weissbein (1995) classified Advanced matrices items as requiring a visuospatial, or a verbal-analytic strategy. We hypothesised that higher AQ scores would predict better performance on visuospatial items than on verbal-analytic items. This prediction was confirmed. These results are consistent with the continuum view and can be explained by the enhanced perceptual functioning theory of performance peaks in ASC. The results also confirm a new prediction about Raven's Advanced Progressive Matrices performance in people with ASC. PMID:21325371

  9. Contour adaptation.

    PubMed

    Anstis, Stuart

    2013-01-01

    It is known that adaptation to a disk that flickers between black and white at 3-8 Hz on a gray surround renders invisible a congruent gray test disk viewed afterwards. This is contrast adaptation. We now report that adapting simply to the flickering circular outline of the disk can have the same effect. We call this "contour adaptation." This adaptation does not transfer interocularly, and apparently applies only to luminance, not color. One can adapt selectively to only some of the contours in a display, making only these contours temporarily invisible. For instance, a plaid comprises a vertical grating superimposed on a horizontal grating. If one first adapts to appropriate flickering vertical lines, the vertical components of the plaid disappears and it looks like a horizontal grating. Also, we simulated a Cornsweet (1970) edge, and we selectively adapted out the subjective and objective contours of a Kanisza (1976) subjective square. By temporarily removing edges, contour adaptation offers a new technique to study the role of visual edges, and it demonstrates how brightness information is concentrated in edges and propagates from them as it fills in surfaces.

  10. Teaching Technology Education to Visually Impaired Students.

    ERIC Educational Resources Information Center

    Mann, Rene

    1987-01-01

    Discusses various types of visual impairments and how the learning environment can be adapted to limit their effect. Presents suggestions for adapting industrial arts laboratory activities to maintain safety standards while allowing the visually impaired to participate. (CH)

  11. On the performance enhancement of adaptive signal averaging: A means for improving the sensitivity and rate of data acquisition in magnetic resonance and other analytical measurements

    NASA Astrophysics Data System (ADS)

    Cochrane, C. J.

    2012-10-01

    A few years back, our lab developed a signal averaging technique that greatly reduces the number of scans required to achieve a comparable signal-to-noise ratio to that of conventional signal averaging for continuous wave magnetic resonance measurements. We utilize an adaptive filter in a signal averaging scheme without any prior knowledge of the signal under observation. We termed this technique adaptive signal averaging (ASA). The technique was successful in reducing the noise variance by a factor of at least 10 in a single trace and is shown to converge in time by the same factor. ASA can also be useful in many other applications where signal averaging is utilized, such as medical imaging, electrocardiography, or electroencephalography. The purpose of this paper is to describe the advancements made to the technique, present a derivation of its performance enhancement, and illustrate the power of the technique through a set of simulations.

  12. Visualizing Qualitative Information

    ERIC Educational Resources Information Center

    Slone, Debra J.

    2009-01-01

    The abundance of qualitative data in today's society and the need to easily scrutinize, digest, and share this information calls for effective visualization and analysis tools. Yet, no existing qualitative tools have the analytic power, visual effectiveness, and universality of familiar quantitative instruments like bar charts, scatter-plots, and…

  13. Target-responsive DNA hydrogel mediated "stop-flow" microfluidic paper-based analytic device for rapid, portable and visual detection of multiple targets.

    PubMed

    Wei, Xiaofeng; Tian, Tian; Jia, Shasha; Zhu, Zhi; Ma, Yanli; Sun, Jianjun; Lin, Zhenyu; Yang, Chaoyong James

    2015-04-21

    A versatile point-of-care assay platform was developed for simultaneous detection of multiple targets based on a microfluidic paper-based analytic device (μPAD) using a target-responsive hydrogel to mediate fluidic flow and signal readout. An aptamer-cross-linked hydrogel was used as a target-responsive flow regulator in the μPAD. In the absence of a target, the hydrogel is formed in the flow channel, stopping the flow in the μPAD and preventing the colored indicator from traveling to the final observation spot, thus yielding a "signal off" readout. In contrast, in the presence of a target, no hydrogel is formed because of the preferential interaction of target and aptamer. This allows free fluidic flow in the μPAD, carrying the indicator to the observation spot and producing a "signal on" readout. The device is inexpensive to fabricate, easy to use, and disposable after detection. Testing results can be obtained within 6 min by the naked eye via a simple loading operation without the need for any auxiliary equipment. Multiple targets, including cocaine, adenosine, and Pb(2+), can be detected simultaneously, even in complex biological matrices such as urine. The reported method offers simple, low cost, rapid, user-friendly, point-of-care testing, which will be useful in many applications.

  14. Conjunctive visual forms.

    PubMed

    Weaver, Chris

    2009-01-01

    Visual exploration of multidimensional data is a process of isolating and extracting relationships within and between dimensions. Coordinated multiple view approaches are particularly effective for visual exploration because they support precise expression of heterogeneous multidimensional queries using simple interactions. Recent visual analytics research has made significant progress in identifying and understanding patterns of composed views and coordinations that support fast, flexible, and open-ended data exploration. What is missing is formalization of the space of expressible queries in terms of visual representation and interaction. This paper introduces the Conjunctive Visual Form model in which visual exploration consists of interactively-driven sequences of transitions between visual states that correspond to conjunctive normal forms in boolean logic. The model predicts several new and useful ways to extend the space of rapidly expressible queries through addition of simple interactive capabilities to existing compositional patterns. Two recent related visual tools offer a subset of these capabilities, providing a basis for conjecturing about such extensions.

  15. Multi-model predictive control based on LMI: from the adaptation of the state-space model to the analytic description of the control law

    NASA Astrophysics Data System (ADS)

    Falugi, P.; Olaru, S.; Dumur, D.

    2010-08-01

    This article proposes an explicit robust predictive control solution based on linear matrix inequalities (LMIs). The considered predictive control strategy uses different local descriptions of the system dynamics and uncertainties and thus allows the handling of less conservative input constraints. The computed control law guarantees constraint satisfaction and asymptotic stability. The technique is effective for a class of nonlinear systems embedded into polytopic models. A detailed discussion of the procedures which adapt the partition of the state space is presented. For the practical implementation the construction of suitable (explicit) descriptions of the control law are described upon concrete algorithms.

  16. Design Issues Adapting a Visual Paper-and-Pencil Test to the Computer: A Case Study--The Figure Classification Test.

    ERIC Educational Resources Information Center

    Washington, James M., Jr.

    This paper documents issues in converting the Figure Classification Test to the computer. The purpose of the test, which is almost entirely visual, is to determine the subject's ability to discover rules via the visual/spatial environment. The methodology of the paper-and-pencil Figure Classification Test is as follows: the subject views a series…

  17. [Adaptive optics for ophthalmology].

    PubMed

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  18. Visualizing Social Networks

    NASA Astrophysics Data System (ADS)

    Correa, Carlos D.; Ma, Kwan-Liu

    With today‘s ubiquity and popularity of social network applications, the ability to analyze and understand large networks in an efficient manner becomes critically important. However, as networks become larger and more complex, reasoning about social dynamics via simple statistics is not a feasible option. To overcome these limitations, we can rely on visual metaphors. Visualization nowadays is no longer a passive process that produces images from a set of numbers. Recent years have witnessed a convergence of social network analytics and visualization, coupled with interaction, that is changing the way analysts understand and characterize social networks. In this chapter, we discuss the main goal of visualization and how different metaphors are aimed towards elucidating different aspects of social networks, such as structure and semantics. We also describe a number of methods where analytics and visualization are interwoven towards providing a better comprehension of social structure and dynamics.

  19. Communication: Spin densities within a unitary group based spin-adapted open-shell coupled-cluster theory: Analytic evaluation of isotropic hyperfine-coupling constants for the combinatoric open-shell coupled-cluster scheme

    SciTech Connect

    Datta, Dipayan Gauss, Jürgen

    2015-07-07

    We report analytical calculations of isotropic hyperfine-coupling constants in radicals using a spin-adapted open-shell coupled-cluster theory, namely, the unitary group based combinatoric open-shell coupled-cluster (COSCC) approach within the singles and doubles approximation. A scheme for the evaluation of the one-particle spin-density matrix required in these calculations is outlined within the spin-free formulation of the COSCC approach. In this scheme, the one-particle spin-density matrix for an open-shell state with spin S and M{sub S} = + S is expressed in terms of the one- and two-particle spin-free (charge) density matrices obtained from the Lagrangian formulation that is used for calculating the analytic first derivatives of the energy. Benchmark calculations are presented for NO, NCO, CH{sub 2}CN, and two conjugated π-radicals, viz., allyl and 1-pyrrolyl in order to demonstrate the performance of the proposed scheme.

  20. Analytical testing

    NASA Technical Reports Server (NTRS)

    Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.

    1981-01-01

    Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.

  1. Forecasting hotspots using predictive visual analytics approach

    DOEpatents

    Maciejewski, Ross; Hafen, Ryan; Rudolph, Stephen; Cleveland, William; Ebert, David

    2014-12-30

    A method for forecasting hotspots is provided. The method may include the steps of receiving input data at an input of the computational device, generating a temporal prediction based on the input data, generating a geospatial prediction based on the input data, and generating output data based on the time series and geospatial predictions. The output data may be configured to display at least one user interface at an output of the computational device.

  2. Visual field

    MedlinePlus

    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 ...

  3. Analytical Microscopy

    SciTech Connect

    Not Available

    2006-06-01

    In the Analytical Microscopy group, within the National Center for Photovoltaic's Measurements and Characterization Division, we combine two complementary areas of analytical microscopy--electron microscopy and proximal-probe techniques--and use a variety of state-of-the-art imaging and analytical tools. We also design and build custom instrumentation and develop novel techniques that provide unique capabilities for studying materials and devices. In our work, we collaborate with you to solve materials- and device-related R&D problems. This sheet summarizes the uses and features of four major tools: transmission electron microscopy, scanning electron microscopy, the dual-beam focused-ion-beam workstation, and scanning probe microscopy.

  4. Analytical Technology

    SciTech Connect

    Goheen, Steven C.

    2001-07-01

    Characterizing environmental samples has been exhaustively addressed in the literature for most analytes of environmental concern. One of the weak areas of environmental analytical chemistry is that of radionuclides and samples contaminated with radionuclides. The analysis of samples containing high levels of radionuclides can be far more complex than that of non-radioactive samples. This chapter addresses the analysis of samples with a wide range of radioactivity. The other areas of characterization examined in this chapter are the hazardous components of mixed waste, and special analytes often associated with radioactive materials. Characterizing mixed waste is often similar to characterizing waste components in non-radioactive materials. The largest differences are in associated safety precautions to minimize exposure to dangerous levels of radioactivity. One must attempt to keep radiological dose as low as reasonably achievable (ALARA). This chapter outlines recommended procedures to safely and accurately characterize regulated components of radioactive samples.

  5. 38 CFR 4.77 - Visual fields.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... who are well adapted to intraocular lens implant or contact lens correction, visual field examinations.... For aphakic individuals not well adapted to contact lens correction or pseudophakic individuals not well adapted to intraocular lens implant, visual field examinations must be conducted using...

  6. 38 CFR 4.77 - Visual fields.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... who are well adapted to intraocular lens implant or contact lens correction, visual field examinations.... For aphakic individuals not well adapted to contact lens correction or pseudophakic individuals not well adapted to intraocular lens implant, visual field examinations must be conducted using...

  7. Age-Specific Effects of Mirror-Muscle Activity on Cross-Limb Adaptations Under Mirror and Non-Mirror Visual Feedback Conditions

    PubMed Central

    Reissig, Paola; Stöckel, Tino; Garry, Michael I.; Summers, Jeffery J.; Hinder, Mark R.

    2015-01-01

    Cross-limb transfer (CLT) describes the observation of bilateral performance gains due to unilateral motor practice. Previous research has suggested that CLT may be reduced, or absent, in older adults, possibly due to age-related structural and functional brain changes. Based on research showing increases in CLT due to the provision of mirror visual feedback (MVF) during task execution in young adults, our study aimed to investigate whether MVF can facilitate CLT in older adults, who are known to be more reliant on visual feedback for accurate motor performance. Participants (N = 53) engaged in a short-term training regime (300 movements) involving a ballistic finger task using their dominant hand, while being provided with either visual feedback of their active limb, or a mirror reflection of their active limb (superimposed over the quiescent limb). Performance in both limbs was examined before, during and following the unilateral training. Furthermore, we measured corticospinal excitability (using TMS) at these time points, and assessed muscle activity bilaterally during the task via EMG; these parameters were used to investigate the mechanisms mediating and predicting CLT. Training resulted in significant bilateral performance gains that did not differ as a result of age or visual feedback (both p > 0.1). Training also elicited bilateral increases in corticospinal excitability (p < 0.05). For younger adults, CLT was significantly predicted by performance gains in the trained hand (β = 0.47), whereas for older adults it was significantly predicted by mirror activity in the untrained hand during training (β = 0.60). The present study suggests that older adults are capable of exhibiting CLT to a similar degree to younger adults. The prominent role of mirror activity in the untrained hand for CLT in older adults indicates that bilateral cortical activity during unilateral motor tasks is a compensatory mechanism. In this particular task, MVF did not facilitate the

  8. Visuo-postural adaptation during the acquisition of a visually guided weight-shifting task: age-related differences in global and local dynamics.

    PubMed

    Hatzitaki, Vassilia; Konstadakos, Stylianos

    2007-10-01

    The effects of aging on the acquisition of a novel visuo-postural coordination task were addressed at two levels: (a) changes in the intersegmental coordination (local dynamics) (b) changes in the coupling of postural sway to the visual driving stimulus (global dynamics). Twelve elderly (age: 71.2 +/- 6.4 years; height: 169.3 +/- 3.8 cm; mass: 72.4 +/- 6.1 kg) and 12 young women (age: 27.1 +/- 4.9 years; height: 178.3 +/- 2.9 cm; mass: 56.7 +/- 4.1 kg) practiced a visually guided Weight-Shifting (WS) task while standing on a dual force platform. The participants were asked to keep the vertical force applied by each limb within a +/-30% force boundary that was visually specified by a target sine-wave signal. Practice consisted of three blocks of five trials performed in 1-day, followed by a block of five trials performed 24 h later. Ground reaction forces and segment (shank, pelvis, and upper trunk) angular kinematics were synchronously sampled through an A/D acquisition board and further analyzed employing spectral and coherence analysis. Elderly women had longer WS cycles, lower response gain, and higher within-trial variability, suggesting a weaker coupling between the visual stimulus and the response force. Spectral analysis of the ground reaction forces confirmed that regardless of age, visuo-postural coupling improved with practice. However, the recruitment of local degrees of freedom was different between the two age groups. With practice, young performers increased peak coherence between the pelvis and the upper trunk and reduced peak power of segment oscillations in the pitch direction. On the other hand, elderly women decreased active upper trunk rotation while shifting control to the lower limb. It is suggested that different functional coordination solutions are possible for attaining the same overall task goal. These solutions are determined by age-related constraints in the physiological systems supporting postural control.

  9. Analytical sedimentology

    SciTech Connect

    Lewis, D.W. . Dept. of Geology); McConchie, D.M. . Centre for Coastal Management)

    1994-01-01

    Both a self instruction manual and a cookbook'' guide to field and laboratory analytical procedures, this book provides an essential reference for non-specialists. With a minimum of mathematics and virtually no theory, it introduces practitioners to easy, inexpensive options for sample collection and preparation, data acquisition, analytic protocols, result interpretation and verification techniques. This step-by-step guide considers the advantages and limitations of different procedures, discusses safety and troubleshooting, and explains support skills like mapping, photography and report writing. It also offers managers, off-site engineers and others using sediments data a quick course in commissioning studies and making the most of the reports. This manual will answer the growing needs of practitioners in the field, either alone or accompanied by Practical Sedimentology, which surveys the science of sedimentology and provides a basic overview of the principles behind the applications.

  10. Tracing Analytic Ray Curves for Light and Sound Propagation in Non-Linear Media.

    PubMed

    Mo, Qi; Yeh, Hengchin; Manocha, Dinesh

    2016-11-01

    The physical world consists of spatially varying media, such as the atmosphere and the ocean, in which light and sound propagates along non-linear trajectories. This presents a challenge to existing ray-tracing based methods, which are widely adopted to simulate propagation due to their efficiency and flexibility, but assume linear rays. We present a novel algorithm that traces analytic ray curves computed from local media gradients, and utilizes the closed-form solutions of both the intersections of the ray curves with planar surfaces, and the travel distance. By constructing an adaptive unstructured mesh, our algorithm is able to model general media profiles that vary in three dimensions with complex boundaries consisting of terrains and other scene objects such as buildings. Our analytic ray curve tracer with the adaptive mesh improves the efficiency considerably over prior methods. We highlight the algorithm's application on simulation of visual and sound propagation in outdoor scenes.

  11. How visualization layout relates to locus of control and other personality factors.

    PubMed

    Ziemkiewicz, Caroline; Ottley, Alvitta; Crouser, R Jordan; Yauilla, Ashley Rye; Su, Sara L; Ribarsky, William; Chang, Remco

    2013-07-01

    Existing research suggests that individual personality differences are correlated with a user's speed and accuracy in solving problems with different types of complex visualization systems. We extend this research by isolating factors in personality traits as well as in the visualizations that could have contributed to the observed correlation. We focus on a personality trait known as "locus of control” (LOC), which represents a person's tendency to see themselves as controlled by or in control of external events. To isolate variables of the visualization design, we control extraneous factors such as color, interaction, and labeling. We conduct a user study with four visualizations that gradually shift from a list metaphor to a containment metaphor and compare the participants' speed, accuracy, and preference with their locus of control and other personality factors. Our findings demonstrate that there is indeed a correlation between the two: participants with an internal locus of control perform more poorly with visualizations that employ a containment metaphor, while those with an external locus of control perform well with such visualizations. These results provide evidence for the externalization theory of visualization. Finally, we propose applications of these findings to adaptive visual analytics and visualization evaluation.

  12. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  13. Analytical toxicology.

    PubMed

    Flanagan, R J; Widdop, B; Ramsey, J D; Loveland, M

    1988-09-01

    1. Major advances in analytical toxicology followed the introduction of spectroscopic and chromatographic techniques in the 1940s and early 1950s and thin layer chromatography remains important together with some spectrophotometric and other tests. However, gas- and high performance-liquid chromatography together with a variety of immunoassay techniques are now widely used. 2. The scope and complexity of forensic and clinical toxicology continues to increase, although the compounds for which emergency analyses are needed to guide therapy are few. Exclusion of the presence of hypnotic drugs can be important in suspected 'brain death' cases. 3. Screening for drugs of abuse has assumed greater importance not only for the management of the habituated patient, but also in 'pre-employment' and 'employment' screening. The detection of illicit drug administration in sport is also an area of increasing importance. 4. In industrial toxicology, the range of compounds for which blood or urine measurements (so called 'biological monitoring') can indicate the degree of exposure is increasing. The monitoring of environmental contaminants (lead, chlorinated pesticides) in biological samples has also proved valuable. 5. In the near future a consensus as to the units of measurement to be used is urgently required and more emphasis will be placed on interpretation, especially as regards possible behavioural effects of drugs or other poisons. Despite many advances in analytical techniques there remains a need for reliable, simple tests to detect poisons for use in smaller hospital and other laboratories.

  14. Report: Analytical Chemistry in a Changing World.

    ERIC Educational Resources Information Center

    Laitinen, H. A.

    1980-01-01

    Examines some of the changes that have occurred in the field of analytic chemistry, with emphasis on how the field has adapted to changes in science and technology. Current trends also are identified and discussed. (CS)

  15. Visual agnosia.

    PubMed

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  16. Developing Tests of Visual Dependency

    NASA Technical Reports Server (NTRS)

    Kindrat, Alexandra N.

    2011-01-01

    Astronauts develop neural adaptive responses to microgravity during space flight. Consequently these adaptive responses cause maladaptive disturbances in balance and gait function when astronauts return to Earth and are re-exposed to gravity. Current research in the Neuroscience Laboratories at NASA-JSC is focused on understanding how exposure to space flight produces post-flight disturbances in balance and gait control and developing training programs designed to facilitate the rapid recovery of functional mobility after space flight. In concert with these disturbances, astronauts also often report an increase in their visual dependency during space flight. To better understand this phenomenon, studies were conducted with specially designed training programs focusing on visual dependency with the aim to understand and enhance subjects ability to rapidly adapt to novel sensory situations. The Rod and Frame test (RFT) was used first to assess an individual s visual dependency, using a variety of testing techniques. Once assessed, subjects were asked to perform two novel tasks under transformation (both the Pegboard and Cube Construction tasks). Results indicate that head position cues and initial visual test conditions had no effect on an individual s visual dependency scores. Subjects were also able to adapt to the manual tasks after several trials. Individual visual dependency correlated with ability to adapt manual to a novel visual distortion only for the cube task. Subjects with higher visual dependency showed decreased ability to adapt to this task. Ultimately, it was revealed that the RFT may serve as an effective prediction tool to produce individualized adaptability training prescriptions that target the specific sensory profile of each crewmember.

  17. Gait adaptation to visual kinematic perturbations using a real-time closed-loop brain–computer interface to a virtual reality avatar

    NASA Astrophysics Data System (ADS)

    Phat Luu, Trieu; He, Yongtian; Brown, Samuel; Nakagame, Sho; Contreras-Vidal, Jose L.

    2016-06-01

    Objective. The control of human bipedal locomotion is of great interest to the field of lower-body brain–computer interfaces (BCIs) for gait rehabilitation. While the feasibility of closed-loop BCI systems for the control of a lower body exoskeleton has been recently shown, multi-day closed-loop neural decoding of human gait in a BCI virtual reality (BCI-VR) environment has yet to be demonstrated. BCI-VR systems provide valuable alternatives for movement rehabilitation when wearable robots are not desirable due to medical conditions, cost, accessibility, usability, or patient preferences. Approach. In this study, we propose a real-time closed-loop BCI that decodes lower limb joint angles from scalp electroencephalography (EEG) during treadmill walking to control a walking avatar in a virtual environment. Fluctuations in the amplitude of slow cortical potentials of EEG in the delta band (0.1–3 Hz) were used for prediction; thus, the EEG features correspond to time-domain amplitude modulated potentials in the delta band. Virtual kinematic perturbations resulting in asymmetric walking gait patterns of the avatar were also introduced to investigate gait adaptation using the closed-loop BCI-VR system over a period of eight days. Main results. Our results demonstrate the feasibility of using a closed-loop BCI to learn to control a walking avatar under normal and altered visuomotor perturbations, which involved cortical adaptations. The average decoding accuracies (Pearson’s r values) in real-time BCI across all subjects increased from (Hip: 0.18 ± 0.31 Knee: 0.23 ± 0.33 Ankle: 0.14 ± 0.22) on Day 1 to (Hip: 0.40 ± 0.24 Knee: 0.55 ± 0.20 Ankle: 0.29 ± 0.22) on Day 8. Significance. These findings have implications for the development of a real-time closed-loop EEG-based BCI-VR system for gait rehabilitation after stroke and for understanding cortical plasticity induced by a closed-loop BCI-VR system.

  18. Gait adaptation to visual kinematic perturbations using a real-time closed-loop brain-computer interface to a virtual reality avatar

    NASA Astrophysics Data System (ADS)

    Phat Luu, Trieu; He, Yongtian; Brown, Samuel; Nakagame, Sho; Contreras-Vidal, Jose L.

    2016-06-01

    Objective. The control of human bipedal locomotion is of great interest to the field of lower-body brain-computer interfaces (BCIs) for gait rehabilitation. While the feasibility of closed-loop BCI systems for the control of a lower body exoskeleton has been recently shown, multi-day closed-loop neural decoding of human gait in a BCI virtual reality (BCI-VR) environment has yet to be demonstrated. BCI-VR systems provide valuable alternatives for movement rehabilitation when wearable robots are not desirable due to medical conditions, cost, accessibility, usability, or patient preferences. Approach. In this study, we propose a real-time closed-loop BCI that decodes lower limb joint angles from scalp electroencephalography (EEG) during treadmill walking to control a walking avatar in a virtual environment. Fluctuations in the amplitude of slow cortical potentials of EEG in the delta band (0.1-3 Hz) were used for prediction; thus, the EEG features correspond to time-domain amplitude modulated potentials in the delta band. Virtual kinematic perturbations resulting in asymmetric walking gait patterns of the avatar were also introduced to investigate gait adaptation using the closed-loop BCI-VR system over a period of eight days. Main results. Our results demonstrate the feasibility of using a closed-loop BCI to learn to control a walking avatar under normal and altered visuomotor perturbations, which involved cortical adaptations. The average decoding accuracies (Pearson’s r values) in real-time BCI across all subjects increased from (Hip: 0.18 ± 0.31 Knee: 0.23 ± 0.33 Ankle: 0.14 ± 0.22) on Day 1 to (Hip: 0.40 ± 0.24 Knee: 0.55 ± 0.20 Ankle: 0.29 ± 0.22) on Day 8. Significance. These findings have implications for the development of a real-time closed-loop EEG-based BCI-VR system for gait rehabilitation after stroke and for understanding cortical plasticity induced by a closed-loop BCI-VR system.

  19. Art Education and Children with Visual Impairments.

    ERIC Educational Resources Information Center

    Wellman, Carla

    1994-01-01

    This article discusses how art activities can be adapted for students with visual impairments, focusing on textural art, sculpture, sound art, smell, taste, kinetic art, dioramas and maps, and computer art. Suggestions for adapting visual arts are also offered, by using good contrast in projects or by enlarging or simplifying pictures. (JDD)

  20. COMMENTARY:Limits to adaptation

    SciTech Connect

    Preston, Benjamin L

    2013-01-01

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.