Neuropsychiatry of complex visual hallucinations.

Science.gov (United States)

Mocellin, Ramon; Walterfang, Mark; Velakoulis, Dennis

2006-09-01

To describe the phenomenology and pathophysiology of complex visual hallucinations (CVH) in various organic states, in particular Charles Bonnet syndrome and peduncular hallucinosis. Three cases of CVH in the setting of pontine infarction, thalamic infarction and temporoparietal epileptiform activity are presented and the available psychiatric, neurological and biological literature on the structures of the central nervous system involved in producing hallucinatory states is reviewed. Complex visual hallucinations can arise from a variety of processes involving the retinogeniculocalcarine tract, or ascending brainstem modulatory structures. The cortical activity responsible for hallucinations results from altered or reduced input into these regions, or a loss of ascending inhibition of their afferent pathways. A significant degree of overlaps exists between the concepts of Charles Bonnet syndrome and peduncular hallucinosis. The fluidity of these eponymous syndromes reduces their validity and meaning, and may result in an inappropriate attribution of the underlying pathology. An understanding of how differing pathologies may produce CVH allows for the appropriate tailoring of treatment, depending on the site and nature of the lesion and content of perceptual disturbance.

Efficient visual search from synchronized auditory signals requires transient audiovisual events.

Directory of Open Access Journals (Sweden)

Erik Van der Burg

Full Text Available BACKGROUND: A prevailing view is that audiovisual integration requires temporally coincident signals. However, a recent study failed to find any evidence for audiovisual integration in visual search even when using synchronized audiovisual events. An important question is what information is critical to observe audiovisual integration. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrate that temporal coincidence (i.e., synchrony of auditory and visual components can trigger audiovisual interaction in cluttered displays and consequently produce very fast and efficient target identification. In visual search experiments, subjects found a modulating visual target vastly more efficiently when it was paired with a synchronous auditory signal. By manipulating the kind of temporal modulation (sine wave vs. square wave vs. difference wave; harmonic sine-wave synthesis; gradient of onset/offset ramps we show that abrupt visual events are required for this search efficiency to occur, and that sinusoidal audiovisual modulations do not support efficient search. CONCLUSIONS/SIGNIFICANCE: Thus, audiovisual temporal alignment will only lead to benefits in visual search if the changes in the component signals are both synchronized and transient. We propose that transient signals are necessary in synchrony-driven binding to avoid spurious interactions with unrelated signals when these occur close together in time.

Electro-Optical Design for Efficient Visual Communication

Science.gov (United States)

Huck, Friedrich O.; Fales, Carl L.; Jobson, Daniel J.; Rahman, Zia-Ur

1995-01-01

Visual communication, in the form of telephotography and television, for example, can be regarded as efficient only if the amount of information that it conveys about the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. Elsewhere we have addressed the problem of assessing the end to end performance of visual communication systems in terms of their efficiency in this sense by integrating the critical limiting factors that constrain image gathering into classical communications theory. We use this approach to assess the electro-optical design of image gathering devices as a function of the f number and apodization of the objective lens and the aperture size and sampling geometry of the phot-detection mechanism. Results show that an image gathering device that is designed to optimize information capacity performs similarly to the human eye. For both, the performance approaches the maximum possible, in terms of the efficiency with which the acquired information can be transmitted as decorrelated data, and the fidelity, sharpness, and clearity with which fine detail can be restored.

Electro-optical design for efficient visual communication

Science.gov (United States)

Huck, Friedrich O.; Fales, Carl L.; Jobson, Daniel J.; Rahman, Zia-ur

1995-03-01

Visual communication, in the form of telephotography and television, for example, can be regarded as efficient only if the amount of information that it conveys about the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. Elsewhere we have addressed the problem of assessing the end-to-end performance of visual communication systems in terms of their efficiency in this sense by integrating the critical limiting factors that constrain image gathering into classical communication theory. We use this approach to assess the electro-optical design of image-gathering devices as a function of the f number and apodization of the objective lens and the aperture size and sampling geometry of the photodetection mechanism. Results show that an image-gathering device that is designed to optimize information capacity performs similarly to the human eye. For both, the performance approaches the maximum possible, in terms of the efficiency with which the acquired information can be transmitted as decorrelated data, and the fidelity, sharpness, and clarity with which fine detail can be restored.

Complexity-aware high efficiency video coding

CERN Document Server

Correa, Guilherme; Agostini, Luciano; Cruz, Luis A da Silva

2016-01-01

This book discusses computational complexity of High Efficiency Video Coding (HEVC) encoders with coverage extending from the analysis of HEVC compression efficiency and computational complexity to the reduction and scaling of its encoding complexity. After an introduction to the topic and a review of the state-of-the-art research in the field, the authors provide a detailed analysis of the HEVC encoding tools compression efficiency and computational complexity.  Readers will benefit from a set of algorithms for scaling the computational complexity of HEVC encoders, all of which take advantage from the flexibility of the frame partitioning structures allowed by the standard.  The authors also provide a set of early termination methods based on data mining and machine learning techniques, which are able to reduce the computational complexity required to find the best frame partitioning structures. The applicability of the proposed methods is finally exemplified with an encoding time control system that emplo...

Decoding complex flow-field patterns in visual working memory.

Science.gov (United States)

Christophel, Thomas B; Haynes, John-Dylan

2014-05-01

There has been a long history of research on visual working memory. Whereas early studies have focused on the role of lateral prefrontal cortex in the storage of sensory information, this has been challenged by research in humans that has directly assessed the encoding of perceptual contents, pointing towards a role of visual and parietal regions during storage. In a previous study we used pattern classification to investigate the storage of complex visual color patterns across delay periods. This revealed coding of such contents in early visual and parietal brain regions. Here we aim to investigate whether the involvement of visual and parietal cortex is also observable for other types of complex, visuo-spatial pattern stimuli. Specifically, we used a combination of fMRI and multivariate classification to investigate the retention of complex flow-field stimuli defined by the spatial patterning of motion trajectories of random dots. Subjects were trained to memorize the precise spatial layout of these stimuli and to retain this information during an extended delay. We used a multivariate decoding approach to identify brain regions where spatial patterns of activity encoded the memorized stimuli. Content-specific memory signals were observable in motion sensitive visual area MT+ and in posterior parietal cortex that might encode spatial information in a modality independent manner. Interestingly, we also found information about the memorized visual stimulus in somatosensory cortex, suggesting a potential crossmodal contribution to memory. Our findings thus indicate that working memory storage of visual percepts might be distributed across unimodal, multimodal and even crossmodal brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

Dependency visualization for complex system understanding

Energy Technology Data Exchange (ETDEWEB)

Smart, J. Allison Cory [Univ. of California, Davis, CA (United States)

1994-09-01

With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impaired as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new organizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.

A low complexity visualization tool that helps to perform complex systems analysis

International Nuclear Information System (INIS)

Beiro, M G; Alvarez-Hamelin, J I; Busch, J R

2008-01-01

In this paper, we present an extension of large network visualization (LaNet-vi), a tool to visualize large scale networks using the k-core decomposition. One of the new features is how vertices compute their angular position. While in the later version it is done using shell clusters, in this version we use the angular coordinate of vertices in higher k-shells, and arrange the highest shell according to a cliques decomposition. The time complexity goes from O(n√n) to O(n) upon bounds on a heavy-tailed degree distribution. The tool also performs a k-core-connectivity analysis, highlighting vertices that are not k-connected; e.g. this property is useful to measure robustness or quality of service (QoS) capabilities in communication networks. Finally, the actual version of LaNet-vi can draw labels and all the edges using transparencies, yielding an accurate visualization. Based on the obtained figure, it is possible to distinguish different sources and types of complex networks at a glance, in a sort of 'network iris-print'.

A low complexity visualization tool that helps to perform complex systems analysis

Science.gov (United States)

Beiró, M. G.; Alvarez-Hamelin, J. I.; Busch, J. R.

2008-12-01

In this paper, we present an extension of large network visualization (LaNet-vi), a tool to visualize large scale networks using the k-core decomposition. One of the new features is how vertices compute their angular position. While in the later version it is done using shell clusters, in this version we use the angular coordinate of vertices in higher k-shells, and arrange the highest shell according to a cliques decomposition. The time complexity goes from O(n\\sqrt n) to O(n) upon bounds on a heavy-tailed degree distribution. The tool also performs a k-core-connectivity analysis, highlighting vertices that are not k-connected; e.g. this property is useful to measure robustness or quality of service (QoS) capabilities in communication networks. Finally, the actual version of LaNet-vi can draw labels and all the edges using transparencies, yielding an accurate visualization. Based on the obtained figure, it is possible to distinguish different sources and types of complex networks at a glance, in a sort of 'network iris-print'.

Similarity, Not Complexity, Determines Visual Working Memory Performance

Science.gov (United States)

Jackson, Margaret C.; Linden, David E. J.; Roberts, Mark V.; Kriegeskorte, Nikolaus; Haenschel, Corinna

2015-01-01

A number of studies have shown that visual working memory (WM) is poorer for complex versus simple items, traditionally accounted for by higher information load placing greater demands on encoding and storage capacity limits. Other research suggests that it may not be complexity that determines WM performance per se, but rather increased…

Supporting Sensemaking of Complex Objects with Visualizations: Visibility and Complementarity of Interactions

Directory of Open Access Journals (Sweden)

Kamran Sedig

2016-10-01

Full Text Available Making sense of complex objects is difficult, and typically requires the use of external representations to support cognitive demands while reasoning about the objects. Visualizations are one type of external representation that can be used to support sensemaking activities. In this paper, we investigate the role of two design strategies in making the interactive features of visualizations more supportive of users’ exploratory needs when trying to make sense of complex objects. These two strategies are visibility and complementarity of interactions. We employ a theoretical framework concerned with human–information interaction and complex cognitive activities to inform, contextualize, and interpret the effects of the design strategies. The two strategies are incorporated in the design of Polyvise, a visualization tool that supports making sense of complex four-dimensional geometric objects. A mixed-methods study was conducted to evaluate the design strategies and the overall usability of Polyvise. We report the findings of the study, discuss some implications for the design of visualization tools that support sensemaking of complex objects, and propose five design guidelines. We anticipate that our results are transferrable to other contexts, and that these two design strategies can be used broadly in visualization tools intended to support activities with complex objects and information spaces.

iview: an interactive WebGL visualizer for protein-ligand complex.

Science.gov (United States)

Li, Hongjian; Leung, Kwong-Sak; Nakane, Takanori; Wong, Man-Hon

2014-02-25

Visualization of protein-ligand complex plays an important role in elaborating protein-ligand interactions and aiding novel drug design. Most existing web visualizers either rely on slow software rendering, or lack virtual reality support. The vital feature of macromolecular surface construction is also unavailable. We have developed iview, an easy-to-use interactive WebGL visualizer of protein-ligand complex. It exploits hardware acceleration rather than software rendering. It features three special effects in virtual reality settings, namely anaglyph, parallax barrier and oculus rift, resulting in visually appealing identification of intermolecular interactions. It supports four surface representations including Van der Waals surface, solvent excluded surface, solvent accessible surface and molecular surface. Moreover, based on the feature-rich version of iview, we have also developed a neat and tailor-made version specifically for our istar web platform for protein-ligand docking purpose. This demonstrates the excellent portability of iview. Using innovative 3D techniques, we provide a user friendly visualizer that is not intended to compete with professional visualizers, but to enable easy accessibility and platform independence.

[Complex visual hallucinations following occipital infarct and perception of optical illusions].

Science.gov (United States)

Renou, P; Deltour, S; Samson, Y

2008-05-01

The physiopathology of visual hallucinations in the hemianopic field secondary to occipital infarct is uncertain. We report the case of a patient with a history of occipital infarct who presented nonstereotyped complex hallucinations in the quadranopic field resulting from a second controlateral occipital infarct. Based on an experience with motion optical illusions, we suggested that the association of these two occipital lesions, involving the V5 motion area on the one side and the V1 area on the other side, could have produced the complex hallucinations due to a release phenomenon. The patient experienced simultaneously a double visual consciousness, with both hallucinations and real visual perceptions. The study of perceptual illusions in patients with visual hallucinations could illustrate the innovative theory of visual consciousness as being not unified but constituted of multiple microconsciousnesses.

Brain signal complexity rises with repetition suppression in visual learning.

Science.gov (United States)

Lafontaine, Marc Philippe; Lacourse, Karine; Lina, Jean-Marc; McIntosh, Anthony R; Gosselin, Frédéric; Théoret, Hugo; Lippé, Sarah

2016-06-21

Neuronal activity associated with visual processing of an unfamiliar face gradually diminishes when it is viewed repeatedly. This process, known as repetition suppression (RS), is involved in the acquisition of familiarity. Current models suggest that RS results from interactions between visual information processing areas located in the occipito-temporal cortex and higher order areas, such as the dorsolateral prefrontal cortex (DLPFC). Brain signal complexity, which reflects information dynamics of cortical networks, has been shown to increase as unfamiliar faces become familiar. However, the complementarity of RS and increases in brain signal complexity have yet to be demonstrated within the same measurements. We hypothesized that RS and brain signal complexity increase occur simultaneously during learning of unfamiliar faces. Further, we expected alteration of DLPFC function by transcranial direct current stimulation (tDCS) to modulate RS and brain signal complexity over the occipito-temporal cortex. Participants underwent three tDCS conditions in random order: right anodal/left cathodal, right cathodal/left anodal and sham. Following tDCS, participants learned unfamiliar faces, while an electroencephalogram (EEG) was recorded. Results revealed RS over occipito-temporal electrode sites during learning, reflected by a decrease in signal energy, a measure of amplitude. Simultaneously, as signal energy decreased, brain signal complexity, as estimated with multiscale entropy (MSE), increased. In addition, prefrontal tDCS modulated brain signal complexity over the right occipito-temporal cortex during the first presentation of faces. These results suggest that although RS may reflect a brain mechanism essential to learning, complementary processes reflected by increases in brain signal complexity, may be instrumental in the acquisition of novel visual information. Such processes likely involve long-range coordinated activity between prefrontal and lower order visual

An efficient visualization method for analyzing biometric data

Science.gov (United States)

Rahmes, Mark; McGonagle, Mike; Yates, J. Harlan; Henning, Ronda; Hackett, Jay

2013-05-01

We introduce a novel application for biometric data analysis. This technology can be used as part of a unique and systematic approach designed to augment existing processing chains. Our system provides image quality control and analysis capabilities. We show how analysis and efficient visualization are used as part of an automated process. The goal of this system is to provide a unified platform for the analysis of biometric images that reduce manual effort and increase the likelihood of a match being brought to an examiner's attention from either a manual or lights-out application. We discuss the functionality of FeatureSCOPE™ which provides an efficient tool for feature analysis and quality control of biometric extracted features. Biometric databases must be checked for accuracy for a large volume of data attributes. Our solution accelerates review of features by a factor of up to 100 times. Review of qualitative results and cost reduction is shown by using efficient parallel visual review for quality control. Our process automatically sorts and filters features for examination, and packs these into a condensed view. An analyst can then rapidly page through screens of features and flag and annotate outliers as necessary.

Investigating Complexity Using Excel and Visual Basic.

Science.gov (United States)

Zetie, K. P.

2001-01-01

Shows how some of the simple ideas in complexity can be investigated using a spreadsheet and a macro written in Visual Basic. Shows how the sandpile model of Bak, Chao, and Wiesenfeld can be simulated and animated. The model produces results that cannot easily be predicted from its properties. (Author/MM)

Visualizing Complex Environments in the Geo- and BioSciences

Science.gov (United States)

Prabhu, A.; Fox, P. A.; Zhong, H.; Eleish, A.; Ma, X.; Zednik, S.; Morrison, S. M.; Moore, E. K.; Muscente, D.; Meyer, M.; Hazen, R. M.

2017-12-01

Earth's living and non-living components have co-evolved for 4 billion years through numerous positive and negative feedbacks. Earth and life scientists have amassed vast amounts of data in diverse fields related to planetary evolution through deep time-mineralogy and petrology, paleobiology and paleontology, paleotectonics and paleomagnetism, geochemistry and geochrononology, genomics and proteomics, and more. Integrating the data from these complimentary disciplines is very useful in gaining an understanding of the evolution of our planet's environment. The integrated data however, represent many extremely complex environments. In order to gain insights and make discoveries using this data, it is important for us to model and visualize these complex environments. As part of work in understanding the "Co-Evolution of Geo and Biospheres using Data Driven Methodologies," we have developed several visualizations to help represent the information stored in the datasets from complimentary disciplines. These visualizations include 2D and 3D force directed Networks, Chord Diagrams, 3D Klee Diagrams. Evolving Network Diagrams, Skyline Diagrams and Tree Diagrams. Combining these visualizations with the results of machine learning and data analysis methods leads to a powerful way to discover patterns and relationships about the Earth's past and today's changing environment.

A lightning strike to the head causing a visual cortex defect with simple and complex visual hallucinations

Science.gov (United States)

Kleiter, Ingo; Luerding, Ralf; Diendorfer, Gerhard; Rek, Helga; Bogdahn, Ulrich; Schalke, Berthold

2009-01-01

The case of a 23-year-old mountaineer who was hit by a lightning strike to the occiput causing a large central visual field defect and bilateral tympanic membrane ruptures is described. Owing to extreme agitation, the patient was sent into a drug-induced coma for 3 days. After extubation, she experienced simple and complex visual hallucinations for several days, but otherwise largely recovered. Neuropsychological tests revealed deficits in fast visual detection tasks and non-verbal learning and indicated a right temporal lobe dysfunction, consistent with a right temporal focus on electroencephalography. At 4 months after the accident, she developed a psychological reaction consisting of nightmares, with reappearance of the complex visual hallucinations and a depressive syndrome. Using the European Cooperation for Lightning Detection network, a meteorological system for lightning surveillance, the exact geographical location and nature of the lightning strike were retrospectively retraced PMID:21734915

Reinforcing Visual Grouping Cues to Communicate Complex Informational Structure.

Science.gov (United States)

Bae, Juhee; Watson, Benjamin

2014-12-01

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

Visual Short-Term Memory Capacity for Simple and Complex Objects

Science.gov (United States)

Luria, Roy; Sessa, Paola; Gotler, Alex; Jolicoeur, Pierre; Dell'Acqua, Roberto

2010-01-01

Does the capacity of visual short-term memory (VSTM) depend on the complexity of the objects represented in memory? Although some previous findings indicated lower capacity for more complex stimuli, other results suggest that complexity effects arise during retrieval (due to errors in the comparison process with what is in memory) that is not…

Sparse Contextual Activation for Efficient Visual Re-Ranking.

Science.gov (United States)

Bai, Song; Bai, Xiang

2016-03-01

In this paper, we propose an extremely efficient algorithm for visual re-ranking. By considering the original pairwise distance in the contextual space, we develop a feature vector called sparse contextual activation (SCA) that encodes the local distribution of an image. Hence, re-ranking task can be simply accomplished by vector comparison under the generalized Jaccard metric, which has its theoretical meaning in the fuzzy set theory. In order to improve the time efficiency of re-ranking procedure, inverted index is successfully introduced to speed up the computation of generalized Jaccard metric. As a result, the average time cost of re-ranking for a certain query can be controlled within 1 ms. Furthermore, inspired by query expansion, we also develop an additional method called local consistency enhancement on the proposed SCA to improve the retrieval performance in an unsupervised manner. On the other hand, the retrieval performance using a single feature may not be satisfactory enough, which inspires us to fuse multiple complementary features for accurate retrieval. Based on SCA, a robust feature fusion algorithm is exploited that also preserves the characteristic of high time efficiency. We assess our proposed method in various visual re-ranking tasks. Experimental results on Princeton shape benchmark (3D object), WM-SRHEC07 (3D competition), YAEL data set B (face), MPEG-7 data set (shape), and Ukbench data set (image) manifest the effectiveness and efficiency of SCA.

Using Complex Auditory-Visual Samples to Produce Emergent Relations in Children with Autism

Science.gov (United States)

Groskreutz, Nicole C.; Karsina, Allen; Miguel, Caio F.; Groskreutz, Mark P.

2010-01-01

Six participants with autism learned conditional relations between complex auditory-visual sample stimuli (dictated words and pictures) and simple visual comparisons (printed words) using matching-to-sample training procedures. Pre- and posttests examined potential stimulus control by each element of the complex sample when presented individually…

AppEEARS: A Simple Tool that Eases Complex Data Integration and Visualization Challenges for Users

Science.gov (United States)

Maiersperger, T.

2017-12-01

The Application for Extracting and Exploring Analysis-Ready Samples (AppEEARS) offers a simple and efficient way to perform discovery, processing, visualization, and acquisition across large quantities and varieties of Earth science data. AppEEARS brings significant value to a very broad array of user communities by 1) significantly reducing data volumes, at-archive, based on user-defined space-time-variable subsets, 2) promoting interoperability across a wide variety of datasets via format and coordinate reference system harmonization, 3) increasing the velocity of both data analysis and insight by providing analysis-ready data packages and by allowing interactive visual exploration of those packages, and 4) ensuring veracity by making data quality measures more apparent and usable and by providing standards-based metadata and processing provenance. Development and operation of AppEEARS is led by the National Aeronautics and Space Administration (NASA) Land Processes Distributed Active Archive Center (LP DAAC). The LP DAAC also partners with several other archives to extend the capability across a larger federation of geospatial data providers. Over one hundred datasets are currently available, covering a diversity of variables including land cover, population, elevation, vegetation indices, and land surface temperature. Many hundreds of users have already used this new web-based capability to make the complex tasks of data integration and visualization much simpler and more efficient.

Main factors of efficiency of automated radiographic complex

International Nuclear Information System (INIS)

Akopov, V.S.; Voronin, S.A.; Grachev, A.V.; Golenishchev, I.A.; Majorov, A.N.; Meshalkin, I.A.

1978-01-01

The amount of work providing an assessment of the efficiency of a complex for automatized radiographic control is considered. The technique involves four stages. An analysis was performed to ascertain the efficiency of control of flaw detectability with regard to each of the stages of radiographic control. The relationships used in determining control efficiency and cited in the paper serve as a foundation for optimizing the technical parameters of the devices of the automatized complex and for creating calculation methods for generalized assessments of the efficiency of radiographic control

Visual Short-Term Memory: is Capacity Dependent on Stimulus Complexity?

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik

complexity - which is dependent on the familiarity of a given stimulus - plays a more important role than the objective visual complexity of the objects stored. In several studies, we explored how familiarity influences the capacity of VSTM and our results indicate that VSTM capacity for familiar items...

Efficient Feature-Driven Visualization of Large-Scale Scientific Data

Energy Technology Data Exchange (ETDEWEB)

Lu, Aidong

2012-12-12

Very large, complex scientific data acquired in many research areas creates critical challenges for scientists to understand, analyze, and organize their data. The objective of this project is to expand the feature extraction and analysis capabilities to develop powerful and accurate visualization tools that can assist domain scientists with their requirements in multiple phases of scientific discovery. We have recently developed several feature-driven visualization methods for extracting different data characteristics of volumetric datasets. Our results verify the hypothesis in the proposal and will be used to develop additional prototype systems.

Visual efficiency among teenaged athletes and non-athletes

Directory of Open Access Journals (Sweden)

Rokiah Omar

2017-09-01

Full Text Available AIM: To compare visual efficiency, specifically accom-modation, vergence, and oculomotor functions among athletes and non-athletes. METHODS: A cross-sectional study on sports vision screening was used to evaluate the visual skills of 214 elementary students (107 athletes, 107 non-athletes, aged between 13 and 16y. The visual screening assessed visual parameters such as ocular motor alignment, accommodation, and vergence functions. RESULTS: Mean visual parameters were compared between age-group matched athletes (mean age 14.82±0.98y and non-athletes (mean age 15.00±1.04y. The refractive errors of all participants were corrected to maximal attainable best corrected visual acuity of logMAR 0.0. Accommodation function assessment evaluated amplitude of accommodation and accommodation facility. Vergence functions measured the near point of convergence, vergence facility, and distance fusional vergence at break and recovery point. Ocular motor alignment was not statistically significant between both groups. Athletes had a statistically significant amplitude of accommodation for both the right eye (t=2.30, P=0.02 and the left eye (t=1.99, P=0.05. Conversely, non-athletes had better accommodation facility (t=-2.54, P=0.01 and near point of convergence (t=4.39, P<0.001 when compared to athletes. Vergence facility was found to be better among athletes (t=2.47, P=0.01. Nevertheless, non-athletes were significantly better for both distance negative and positive fusional vergence. CONCLUSION: Although the findings are still inconclusive as to whether athletes had superior visual skills as compared to non-athletes, it remains important to identify and elucidate the key visual skills needed by athletes in order for them to achieve higher performance in their sports.

Visualizing complex (hydrological) systems with correlation matrices

Science.gov (United States)

Haas, J. C.

2016-12-01

When trying to understand or visualize the connections of different aspects of a complex system, this often requires deeper understanding to start with, or - in the case of geo data - complicated GIS software. To our knowledge, correlation matrices have rarely been used in hydrology (e.g. Stoll et al., 2011; van Loon and Laaha, 2015), yet they do provide an interesting option for data visualization and analysis. We present a simple, python based way - using a river catchment as an example - to visualize correlations and similarities in an easy and colorful way. We apply existing and easy to use python packages from various disciplines not necessarily linked to the Earth sciences and can thus quickly show how different aquifers work or react, and identify outliers, enabling this system to also be used for quality control of large datasets. Going beyond earlier work, we add a temporal and spatial element, enabling us to visualize how a system reacts to local phenomena such as for example a river, or changes over time, by visualizing the passing of time in an animated movie. References: van Loon, A.F., Laaha, G.: Hydrological drought severity explained by climate and catchment characteristics, Journal of Hydrology 526, 3-14, 2015, Drought processes, modeling, and mitigation Stoll, S., Hendricks Franssen, H. J., Barthel, R., Kinzelbach, W.: What can we learn from long-term groundwater data to improve climate change impact studies?, Hydrology and Earth System Sciences 15(12), 3861-3875, 2011

Efficient organic light-emitting devices with platinum-complex emissive layer

KAUST Repository

Yang, Xiaohui

2011-01-18

We report efficient organic light-emitting devices having a platinum-complex emissive layer with the peak external quantum efficiency of 17.5% and power efficiency of 45 lm W−1. Variation in the device performance with platinum-complex layer thickness can be attributed to the interplay between carrier recombination and intermolecular interactions in the layer. Efficient white devices using double platinum-complex layers show the external quantum efficiency of 10%, the Commission Internationale d’Énclairage coordinates of (0.42, 0.41), and color rendering index of 84 at 1000 cd m−2.

Efficient organic light-emitting devices with platinum-complex emissive layer

KAUST Repository

Yang, Xiaohui; Wu, Fang-Iy; Haverinen, Hanna; Li, Jian; Cheng, Chien-Hong; Jabbour, Ghassan E.

2011-01-01

We report efficient organic light-emitting devices having a platinum-complex emissive layer with the peak external quantum efficiency of 17.5% and power efficiency of 45 lm W−1. Variation in the device performance with platinum-complex layer thickness can be attributed to the interplay between carrier recombination and intermolecular interactions in the layer. Efficient white devices using double platinum-complex layers show the external quantum efficiency of 10%, the Commission Internationale d’Énclairage coordinates of (0.42, 0.41), and color rendering index of 84 at 1000 cd m−2.

Low-complex energy-aware image communication in visual sensor networks

Science.gov (United States)

Phamila, Yesudhas Asnath Victy; Amutha, Ramachandran

2013-10-01

A low-complex, low bit rate, energy-efficient image compression algorithm explicitly designed for resource-constrained visual sensor networks applied for surveillance, battle field, habitat monitoring, etc. is presented, where voluminous amount of image data has to be communicated over a bandwidth-limited wireless medium. The proposed method overcomes the energy limitation of individual nodes and is investigated in terms of image quality, entropy, processing time, overall energy consumption, and system lifetime. This algorithm is highly energy efficient and extremely fast since it applies energy-aware zonal binary discrete cosine transform (DCT) that computes only the few required significant coefficients and codes them using enhanced complementary Golomb Rice code without using any floating point operations. Experiments are performed using the Atmel Atmega128 and MSP430 processors to measure the resultant energy savings. Simulation results show that the proposed energy-aware fast zonal transform consumes only 0.3% of energy needed by conventional DCT. This algorithm consumes only 6% of energy needed by Independent JPEG Group (fast) version, and it suits for embedded systems requiring low power consumption. The proposed scheme is unique since it significantly enhances the lifetime of the camera sensor node and the network without any need for distributed processing as was traditionally required in existing algorithms.

Fornix and medial temporal lobe lesions lead to comparable deficits in complex visual perception.

Science.gov (United States)

Lech, Robert K; Koch, Benno; Schwarz, Michael; Suchan, Boris

2016-05-04

Recent research dealing with the structures of the medial temporal lobe (MTL) has shifted away from exclusively investigating memory-related processes and has repeatedly incorporated the investigation of complex visual perception. Several studies have demonstrated that higher level visual tasks can recruit structures like the hippocampus and perirhinal cortex in order to successfully perform complex visual discriminations, leading to a perceptual-mnemonic or representational view of the medial temporal lobe. The current study employed a complex visual discrimination paradigm in two patients suffering from brain lesions with differing locations and origin. Both patients, one with extensive medial temporal lobe lesions (VG) and one with a small lesion of the anterior fornix (HJK), were impaired in complex discriminations while showing otherwise mostly intact cognitive functions. The current data confirmed previous results while also extending the perceptual-mnemonic theory of the MTL to the main output structure of the hippocampus, the fornix. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Postural sway and gaze can track the complex motion of a visual target.

Directory of Open Access Journals (Sweden)

Vassilia Hatzitaki

Full Text Available Variability is an inherent and important feature of human movement. This variability has form exhibiting a chaotic structure. Visual feedback training using regular predictive visual target motions does not take into account this essential characteristic of the human movement, and may result in task specific learning and loss of visuo-motor adaptability. In this study, we asked how well healthy young adults can track visual target cues of varying degree of complexity during whole-body swaying in the Anterior-Posterior (AP and Medio-Lateral (ML direction. Participants were asked to track three visual target motions: a complex (Lorenz attractor, a noise (brown and a periodic (sine moving target while receiving online visual feedback about their performance. Postural sway, gaze and target motion were synchronously recorded and the degree of force-target and gaze-target coupling was quantified using spectral coherence and Cross-Approximate entropy. Analysis revealed that both force-target and gaze-target coupling was sensitive to the complexity of the visual stimuli motions. Postural sway showed a higher degree of coherence with the Lorenz attractor than the brown noise or sinusoidal stimulus motion. Similarly, gaze was more synchronous with the Lorenz attractor than the brown noise and sinusoidal stimulus motion. These results were similar regardless of whether tracking was performed in the AP or ML direction. Based on the theoretical model of optimal movement variability tracking of a complex signal may provide a better stimulus to improve visuo-motor adaptation and learning in postural control.

Superior and efficiency sport of visually impaired people in the Czech Republic

OpenAIRE

Trnka, Václav

2008-01-01

Project: Superior and efficiency sport of visually impaired people in the Czech Republic Aim of the project: The aim of the project is to compile an overview about Paralympic and selected sports that are done by visually impaired people here in the Czech Republic. The overview includes basic information about specification of individual sports of visually impaired persons as well as updated description of organization of sports for such disabled persons. Based on these facts it makes suggesti...

Heat conversion alternative petrochemical complexes efficiency

Science.gov (United States)

Mrakin, A. N.; Selivanov, A. A.; Morev, A. A.; Batrakov, P. A.; Kulbyakina, A. V.; Sotnikov, D. G.

2017-08-01

The paper presents the energy and economic efficiency calculation results of the petrochemical complexes based upon the sulfur oil shales processing by solid (ash) heat-carrier low-temperature carbonization plants by Galoter technology. The criterion for such enterprises fuel efficiency determining was developed on the base of the exergy methodology taking into account the recurrent publications consolidation. In this case, in supplying the consumers with paving bitumen, motor benzol, thiophene, toluene, 2-methylthiophene, xylene, gas sulfur, complex thermodynamic effectiveness was founded to amount to 53 %, and if ash residue realization is possible then it was founded to be to 70 %. The project economic attractiveness determining studies depending on the feedstock cost, its delivery way and investments amount changing were conducted.

How to improve the efficient use of functional vision of people with visual impairment

OpenAIRE

Mohorko, Ana

2013-01-01

Barraga was the first researcher to study the effects of a special program for developing visual efficiency which showed improvements in visual acuity and visual functioning in blind children with remaining vision. Her breakthrough findings helped develop new theories of visual functioning. These theories represent a foundation from which a professional can understand the visual functioning of an individual with low vision. Providing opportunities for individuals to learn how to use their vis...

Adolescents' and adults' visual preferences for pictures of fruit and vegetable mixes -effect of complexity

DEFF Research Database (Denmark)

Mielby, Line Holler; Kildegaard, Heidi; Gabrielsen, G.

2012-01-01

Complexity is an important parameter for the appreciation of foods as a bell-shaped relationship between hedonic appreciation and complexity has been found by Berlyne (1970). The aim of this study was to examine the relationship between adolescent and adult visual preferences and perceived...... complexity for vegetable (V), fruit (F), and combined fruit and vegetable (FV) mixes. Two hundred and forty-two adolescents and 119 adults performed three incomplete rankings of visual preference of eight pictures of V mixes, eight pictures of F mixes, and eight pictures of FV mixes, respectively. The three...... correlations between designed collative properties and perceived complexity. Inverted U-shaped relationships between visual preference and perceived complexity were found for both the V mixes and the F mixes but not for the FV mixes. For the V and the F mixes, the subjects’ optimal level of complexity...

When complex is easy on the mind: internal repetition of visual information in complex objects is a source of perceptual fluency

NARCIS (Netherlands)

Linda Steg; Roos Pals; Ayça Berfu Ünal; Yannick Joye

2015-01-01

Across 3 studies, we investigated whether visual complexity deriving from internally repeating visual information over many scale levels is a source of perceptual fluency. Such continuous repetition of visual information is formalized in fractal geometry and is a key-property of natural structures.

Efficient Cross-Modal Transfer of Shape Information in Visual and Haptic Object Categorization

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Nina Gaissert

2011-10-01

Full Text Available Categorization has traditionally been studied in the visual domain with only a few studies focusing on the abilities of the haptic system in object categorization. During the first years of development, however, touch and vision are closely coupled in the exploratory procedures used by the infant to gather information about objects. Here, we investigate how well shape information can be transferred between those two modalities in a categorization task. Our stimuli consisted of amoeba-like objects that were parametrically morphed in well-defined steps. Participants explored the objects in a categorization task either visually or haptically. Interestingly, both modalities led to similar categorization behavior suggesting that similar shape processing might occur in vision and haptics. Next, participants received training on specific categories in one of the two modalities. As would be expected, training increased performance in the trained modality; however, we also found significant transfer of training to the other, untrained modality after only relatively few training trials. Taken together, our results demonstrate that complex shape information can be transferred efficiently across the two modalities, which speaks in favor of multisensory, higher-level representations of shape.

The Effects of Visual Complexity for Japanese Kanji Processing with High and Low Frequencies

Science.gov (United States)

Tamaoka, Katsuo; Kiyama, Sachiko

2013-01-01

The present study investigated the effects of visual complexity for kanji processing by selecting target kanji from different stroke ranges of visually simple (2-6 strokes), medium (8-12 strokes), and complex (14-20 strokes) kanji with high and low frequencies. A kanji lexical decision task in Experiment 1 and a kanji naming task in Experiment 2…

Pareidolias: complex visual illusions in dementia with Lewy bodies.

Science.gov (United States)

Uchiyama, Makoto; Nishio, Yoshiyuki; Yokoi, Kayoko; Hirayama, Kazumi; Imamura, Toru; Shimomura, Tatsuo; Mori, Etsuro

2012-08-01

Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development

Visualization and simulation of complex flows in biomedical engineering

CERN Document Server

Imai, Yohsuke; Ishikawa, Takuji; Oliveira, Mónica

2014-01-01

This book focuses on the most recent advances in the application of visualization and simulation methods to understand the flow behavior of complex fluids used in biomedical engineering and other related fields. It shows the physiological flow behavior in large arteries, microcirculation, respiratory systems and in biomedical microdevices.

The Effects of Pictorial Complexity and Cognitive Style on Visual Recall Memory.

Science.gov (United States)

Jesky, Romaine R.; Berry, Louis H.

The effect of the interaction between cognitive style differences (field dependence/field independence) and various degrees of visual complexity on pictorial recall memory was explored using three sets of visuals in three different formats--line drawing, black and white, and color. The subjects were 86 undergraduate students enrolled in two core…

Chess players' eye movements reveal rapid recognition of complex visual patterns: Evidence from a chess-related visual search task.

Science.gov (United States)

Sheridan, Heather; Reingold, Eyal M

2017-03-01

To explore the perceptual component of chess expertise, we monitored the eye movements of expert and novice chess players during a chess-related visual search task that tested anecdotal reports that a key differentiator of chess skill is the ability to visualize the complex moves of the knight piece. Specifically, chess players viewed an array of four minimized chessboards, and they rapidly searched for the target board that allowed a knight piece to reach a target square in three moves. On each trial, there was only one target board (i.e., the "Yes" board), and for the remaining "lure" boards, the knight's path was blocked on either the first move (the "Easy No" board) or the second move (i.e., "the Difficult No" board). As evidence that chess experts can rapidly differentiate complex chess-related visual patterns, the experts (but not the novices) showed longer first-fixation durations on the "Yes" board relative to the "Difficult No" board. Moreover, as hypothesized, the task strongly differentiated chess skill: Reaction times were more than four times faster for the experts relative to novices, and reaction times were correlated with within-group measures of expertise (i.e., official chess ratings, number of hours of practice). These results indicate that a key component of chess expertise is the ability to rapidly recognize complex visual patterns.

Effective and Efficient Stand Magnifier Use in Visually Impaired Children

NARCIS (Netherlands)

Liebrand-Schurink, Joyce; Cox, Ralf F. A.; van Rens, Ger H. M. B.; Cillessen, Antonius H. N.; Meulenbroek, Ruud G. J.; Boonstra, Frouke N.

2016-01-01

Purpose: The main objective of this study was to analyze the effectiveness and efficiency of magnifier use in children with visual impairment who did not use a low vision aid earlier, in an ecologically valid goal-directed perceptuomotor task. Methods: Participants were twenty-nine 4- to 8-year-old

Efficient Unsteady Flow Visualization with High-Order Access Dependencies

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru

2016-04-19

We present a novel high-order access dependencies based model for efficient pathline computation in unsteady flow visualization. By taking longer access sequences into account to model more sophisticated data access patterns in particle tracing, our method greatly improves the accuracy and reliability in data access prediction. In our work, high-order access dependencies are calculated by tracing uniformly-seeded pathlines in both forward and backward directions in a preprocessing stage. The effectiveness of our proposed approach is demonstrated through a parallel particle tracing framework with high-order data prefetching. Results show that our method achieves higher data locality and hence improves the efficiency of pathline computation.

Consistent two-dimensional visualization of protein-ligand complex series

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Stierand Katrin

2011-06-01

Full Text Available Abstract Background The comparative two-dimensional graphical representation of protein-ligand complex series featuring different ligands bound to the same active site offers a quick insight in their binding mode differences. In comparison to arbitrary orientations of the residue molecules in the individual complex depictions a consistent placement improves the legibility and comparability within the series. The automatic generation of such consistent layouts offers the possibility to apply it to large data sets originating from computer-aided drug design methods. Results We developed a new approach, which automatically generates a consistent layout of interacting residues for a given series of complexes. Based on the structural three-dimensional input information, a global two-dimensional layout for all residues of the complex ensemble is computed. The algorithm incorporates the three-dimensional adjacencies of the active site residues in order to find an universally valid circular arrangement of the residues around the ligand. Subsequent to a two-dimensional ligand superimposition step, a global placement for each residue is derived from the set of already placed ligands. The method generates high-quality layouts, showing mostly overlap-free solutions with molecules which are displayed as structure diagrams providing interaction information in atomic detail. Application examples document an improved legibility compared to series of diagrams whose layouts are calculated independently from each other. Conclusions The presented method extends the field of complex series visualizations. A series of molecules binding to the same protein active site is drawn in a graphically consistent way. Compared to existing approaches these drawings substantially simplify the visual analysis of large compound series.

GeoVisual Analytics for the Exploration of Complex Movement Patterns on Arterial Roads

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels

2018-01-01

Visualization of complex spatio-temporal traffic movements on the road network is a challenging task since it requires simultaneous representation of vehicle measurement characteristics and traffic network regulation rules. Previously proposed visual representations addressed issues related....... Arterial roads are important for the mobility and connectivity of modern society, but they also have traffic regulations that are not always followed by the vulnerable road users. In order to understand complex movement behaviors between vehicle drivers and pedestrians on the arterial roads, a Geo......Visual Analytics approach was developed in dialog with traffic experts. The exploratory interactive tools have assisted experts to extract unknown information about movement patterns from large traffic data at different levels of details. The results of the analysis revealed detailed patterns of speed variations...

Target-nontarget similarity decreases search efficiency and increases stimulus-driven control in visual search.

Science.gov (United States)

Barras, Caroline; Kerzel, Dirk

2017-10-01

Some points of criticism against the idea that attentional selection is controlled by bottom-up processing were dispelled by the attentional window account. The attentional window account claims that saliency computations during visual search are only performed for stimuli inside the attentional window. Therefore, a small attentional window may avoid attentional capture by salient distractors because it is likely that the salient distractor is located outside the window. In contrast, a large attentional window increases the chances of attentional capture by a salient distractor. Large and small attentional windows have been associated with efficient (parallel) and inefficient (serial) search, respectively. We compared the effect of a salient color singleton on visual search for a shape singleton during efficient and inefficient search. To vary search efficiency, the nontarget shapes were either similar or dissimilar with respect to the shape singleton. We found that interference from the color singleton was larger with inefficient than efficient search, which contradicts the attentional window account. While inconsistent with the attentional window account, our results are predicted by computational models of visual search. Because of target-nontarget similarity, the target was less salient with inefficient than efficient search. Consequently, the relative saliency of the color distractor was higher with inefficient than with efficient search. Accordingly, stronger attentional capture resulted. Overall, the present results show that bottom-up control by stimulus saliency is stronger when search is difficult, which is inconsistent with the attentional window account.

Working memory load predicts visual search efficiency: Evidence from a novel pupillary response paradigm.

Science.gov (United States)

Attar, Nada; Schneps, Matthew H; Pomplun, Marc

2016-10-01

An observer's pupil dilates and constricts in response to variables such as ambient and focal luminance, cognitive effort, the emotional stimulus content, and working memory load. The pupil's memory load response is of particular interest, as it might be used for estimating observers' memory load while they are performing a complex task, without adding an interruptive and confounding memory test to the protocol. One important task in which working memory's involvement is still being debated is visual search, and indeed a previous experiment by Porter, Troscianko, and Gilchrist (Quarterly Journal of Experimental Psychology, 60, 211-229, 2007) analyzed observers' pupil sizes during search to study this issue. These authors found that pupil size increased over the course of the search, and they attributed this finding to accumulating working memory load. However, since the pupil response is slow and does not depend on memory load alone, this conclusion is rather speculative. In the present study, we estimated working memory load in visual search during the presentation of intermittent fixation screens, thought to induce a low, stable level of arousal and cognitive effort. Using standard visual search and control tasks, we showed that this paradigm reduces the influence of non-memory-related factors on pupil size. Furthermore, we found an early increase in working memory load to be associated with more efficient search, indicating a significant role of working memory in the search process.

Phosphorescent cyclometalated complexes for efficient blue organic light-emitting diodes

Science.gov (United States)

Suzuri, Yoshiyuki; Oshiyama, Tomohiro; Ito, Hiroto; Hiyama, Kunihisa; Kita, Hiroshi

2014-10-01

Phosphorescent emitters are extremely important for efficient organic light-emitting diodes (OLEDs), which attract significant attention. Phosphorescent emitters, which have a high phosphorescence quantum yield at room temperature, typically contain a heavy metal such as iridium and have been reported to emit blue, green and red light. In particular, the blue cyclometalated complexes with high efficiency and high stability are being developed. In this review, we focus on blue cyclometalated complexes. Recent progress of computational analysis necessary to design a cyclometalated complex is introduced. The prediction of the radiative transition is indispensable to get an emissive cyclometalated complex. We summarize four methods to control phosphorescence peak of the cyclometalated complex: (i) substituent effect on ligands, (ii) effects of ancillary ligands on heteroleptic complexes, (iii) design of the ligand skeleton, and (iv) selection of the central metal. It is considered that novel ligand skeletons would be important to achieve both a high efficiency and long lifetime in the blue OLEDs. Moreover, the combination of an emitter and a host is important as well as the emitter itself. According to the dependences on the combination of an emitter and a host, the control of exciton density of the triplet is necessary to achieve both a high efficiency and a long lifetime, because the annihilations of the triplet state cause exciton quenching and material deterioration.

Nonuniform Changes in the Distribution of Visual Attention from Visual Complexity and Action: A Driving Simulation Study.

Science.gov (United States)

Park, George D; Reed, Catherine L

2015-02-01

Researchers acknowledge the interplay between action and attention, but typically consider action as a response to successful attentional selection or the correlation of performance on separate action and attention tasks. We investigated how concurrent action with spatial monitoring affects the distribution of attention across the visual field. We embedded a functional field of view (FFOV) paradigm with concurrent central object recognition and peripheral target localization tasks in a simulated driving environment. Peripheral targets varied across 20-60 deg eccentricity at 11 radial spokes. Three conditions assessed the effects of visual complexity and concurrent action on the size and shape of the FFOV: (1) with no background, (2) with driving background, and (3) with driving background and vehicle steering. The addition of visual complexity slowed task performance and reduced the FFOV size but did not change the baseline shape. In contrast, the addition of steering produced not only shrinkage of the FFOV, but also changes in the FFOV shape. Nonuniform performance decrements occurred in proximal regions used for the central task and for steering, independent of interference from context elements. Multifocal attention models should consider the role of action and account for nonhomogeneities in the distribution of attention. © 2015 SAGE Publications.

Visual Analytics of Complex Genomics Data to Guide Effective Treatment Decisions

Directory of Open Access Journals (Sweden)

Quang Vinh Nguyen

2016-09-01

Full Text Available In cancer biology, genomics represents a big data problem that needs accurate visual data processing and analytics. The human genome is very complex with thousands of genes that contain the information about the individual patients and the biological mechanisms of their disease. Therefore, when building a framework for personalised treatment, the complexity of the genome must be captured in meaningful and actionable ways. This paper presents a novel visual analytics framework that enables effective analysis of large and complex genomics data. By providing interactive visualisations from the overview of the entire patient cohort to the detail view of individual genes, our work potentially guides effective treatment decisions for childhood cancer patients. The framework consists of multiple components enabling the complete analytics supporting personalised medicines, including similarity space construction, automated analysis, visualisation, gene-to-gene comparison and user-centric interaction and exploration based on feature selection. In addition to the traditional way to visualise data, we utilise the Unity3D platform for developing a smooth and interactive visual presentation of the information. This aims to provide better rendering, image quality, ergonomics and user experience to non-specialists or young users who are familiar with 3D gaming environments and interfaces. We illustrate the effectiveness of our approach through case studies with datasets from childhood cancers, B-cell Acute Lymphoblastic Leukaemia (ALL and Rhabdomyosarcoma (RMS patients, on how to guide the effective treatment decision in the cohort.

Visual search in ecological and non-ecological displays: evidence for a non-monotonic effect of complexity on performance.

Directory of Open Access Journals (Sweden)

Philippe Chassy

Full Text Available Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate with chess players of two levels of expertise (novices and club players. Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions and ecologically valid (game positions stimuli: With artificial, but not with ecologically valid stimuli, a "pop out" effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.

Ultrascale Visualization of Climate Data

Energy Technology Data Exchange (ETDEWEB)

Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doutriaux, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Patchett, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Sean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shipman, Galen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Ross G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pugmire, Dave [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Brian E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Steed, Chad A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Childs, Hank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Krishnan, Harinarayan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Silva, Claudio T. [New York University, New York, NY (United States). Center for Urban Sciences; Santos, Emanuele [Universidade Federal do Ceara, Ceara (Brazil); Koop, David [New York University, New York, NY (United States); Ellqvist, Tommy [New York University, New York, NY (United States); Poco, Jorge [Polytechnic Institute of New York University, New York, NY (United States); Geveci, Berk [Kitware Inc., Clifton Park, NY (United States); Chaudhary, Aashish [Kitware Inc., Clifton Park, NY (United States); Bauer, Andy [Kitware Inc., Clifton Park, NY (United States); Pletzer, Alexander [Tech-X Corporation, Boulder, CO (United States); Kindig, Dave [Tech-X Corporation, Boulder, CO (United States); Potter, Gerald [National Aeronautics and Space Administration (NASA), Washington, DC (United States); Maxwell, Thomas P. [National Aeronautics and Space Administration (NASA), Washington, DC (United States)

2013-09-01

To support interactive visualization and analysis of complex, large-scale climate data sets, UV-CDAT integrates a powerful set of scientific computing libraries and applications to foster more efficient knowledge discovery. Connected through a provenance framework, the UV-CDAT components can be loosely coupled for fast integration or tightly coupled for greater functionality and communication with other components. This framework addresses many challenges in the interactive visual analysis of distributed large-scale data for the climate community.

A Mathematical Approach to Supply Complexity Management Efficiency Evaluation for Supply Chain

Directory of Open Access Journals (Sweden)

Changhee Kim

2015-01-01

Full Text Available This study aims to identify the factors of complexity due to the globalization of supply chain and to measure the management efficiency of the factors which cause the supply complexity within supply chain. This study conducts an analysis to utilize linear programming and bootstrapping, targeting 12 Korean companies among the selected companies in Fortune Global 500. According to the results from the analysis, 4 companies with relatively high management efficiency of the factors which cause the supply complexity and 8 companies with relatively low management efficiency are found. The research findings reveal that public companies with the small number of products, factories, and providers relatively manage the supply complexity compared to private companies. Moreover, this study suggests projection point as a direction for relatively less efficient companies and excess quantity of input which should reduce for its achievement. This study also has an implication to establish a further standard of efficiency to manage the supply complexity for companies.

Efficient data exchange: Integrating a vector GIS with an object-oriented, 3-D visualization system

International Nuclear Information System (INIS)

Kuiper, J.; Ayers, A.; Johnson, R.; Tolbert-Smith, M.

1996-01-01

A common problem encountered in Geographic Information System (GIS) modeling is the exchange of data between different software packages to best utilize the unique features of each package. This paper describes a project to integrate two systems through efficient data exchange. The first is a widely used GIS based on a relational data model. This system has a broad set of data input, processing, and output capabilities, but lacks three-dimensional (3-D) visualization and certain modeling functions. The second system is a specialized object-oriented package designed for 3-D visualization and modeling. Although this second system is useful for subsurface modeling and hazardous waste site characterization, it does not provide many of the, capabilities of a complete GIS. The system-integration project resulted in an easy-to-use program to transfer information between the systems, making many of the more complex conversion issues transparent to the user. The strengths of both systems are accessible, allowing the scientist more time to focus on analysis. This paper details the capabilities of the two systems, explains the technical issues associated with data exchange and how they were solved, and outlines an example analysis project that used the integrated systems

MMTF-An efficient file format for the transmission, visualization, and analysis of macromolecular structures.

Directory of Open Access Journals (Sweden)

Anthony R Bradley

2017-06-01

Full Text Available Recent advances in experimental techniques have led to a rapid growth in complexity, size, and number of macromolecular structures that are made available through the Protein Data Bank. This creates a challenge for macromolecular visualization and analysis. Macromolecular structure files, such as PDB or PDBx/mmCIF files can be slow to transfer, parse, and hard to incorporate into third-party software tools. Here, we present a new binary and compressed data representation, the MacroMolecular Transmission Format, MMTF, as well as software implementations in several languages that have been developed around it, which address these issues. We describe the new format and its APIs and demonstrate that it is several times faster to parse, and about a quarter of the file size of the current standard format, PDBx/mmCIF. As a consequence of the new data representation, it is now possible to visualize structures with millions of atoms in a web browser, keep the whole PDB archive in memory or parse it within few minutes on average computers, which opens up a new way of thinking how to design and implement efficient algorithms in structural bioinformatics. The PDB archive is available in MMTF file format through web services and data that are updated on a weekly basis.

Efficient visual object and word recognition relies on high spatial frequency coding in the left posterior fusiform gyrus: evidence from a case-series of patients with ventral occipito-temporal cortex damage.

Science.gov (United States)

Roberts, Daniel J; Woollams, Anna M; Kim, Esther; Beeson, Pelagie M; Rapcsak, Steven Z; Lambon Ralph, Matthew A

2013-11-01

Recent visual neuroscience investigations suggest that ventral occipito-temporal cortex is retinotopically organized, with high acuity foveal input projecting primarily to the posterior fusiform gyrus (pFG), making this region crucial for coding high spatial frequency information. Because high spatial frequencies are critical for fine-grained visual discrimination, we hypothesized that damage to the left pFG should have an adverse effect not only on efficient reading, as observed in pure alexia, but also on the processing of complex non-orthographic visual stimuli. Consistent with this hypothesis, we obtained evidence that a large case series (n = 20) of patients with lesions centered on left pFG: 1) Exhibited reduced sensitivity to high spatial frequencies; 2) demonstrated prolonged response latencies both in reading (pure alexia) and object naming; and 3) were especially sensitive to visual complexity and similarity when discriminating between novel visual patterns. These results suggest that the patients' dual reading and non-orthographic recognition impairments have a common underlying mechanism and reflect the loss of high spatial frequency visual information normally coded in the left pFG.

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

Science.gov (United States)

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

2015-09-01

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.

Reactome graph database: Efficient access to complex pathway data

Science.gov (United States)

Korninger, Florian; Viteri, Guilherme; Marin-Garcia, Pablo; Ping, Peipei; Wu, Guanming; Stein, Lincoln; D’Eustachio, Peter

2018-01-01

Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. One of its main priorities is to provide easy and efficient access to its high quality curated data. At present, biological pathway databases typically store their contents in relational databases. This limits access efficiency because there are performance issues associated with queries traversing highly interconnected data. The same data in a graph database can be queried more efficiently. Here we present the rationale behind the adoption of a graph database (Neo4j) as well as the new ContentService (REST API) that provides access to these data. The Neo4j graph database and its query language, Cypher, provide efficient access to the complex Reactome data model, facilitating easy traversal and knowledge discovery. The adoption of this technology greatly improved query efficiency, reducing the average query time by 93%. The web service built on top of the graph database provides programmatic access to Reactome data by object oriented queries, but also supports more complex queries that take advantage of the new underlying graph-based data storage. By adopting graph database technology we are providing a high performance pathway data resource to the community. The Reactome graph database use case shows the power of NoSQL database engines for complex biological data types. PMID:29377902

Reactome graph database: Efficient access to complex pathway data.

Directory of Open Access Journals (Sweden)

Antonio Fabregat

2018-01-01

Full Text Available Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. One of its main priorities is to provide easy and efficient access to its high quality curated data. At present, biological pathway databases typically store their contents in relational databases. This limits access efficiency because there are performance issues associated with queries traversing highly interconnected data. The same data in a graph database can be queried more efficiently. Here we present the rationale behind the adoption of a graph database (Neo4j as well as the new ContentService (REST API that provides access to these data. The Neo4j graph database and its query language, Cypher, provide efficient access to the complex Reactome data model, facilitating easy traversal and knowledge discovery. The adoption of this technology greatly improved query efficiency, reducing the average query time by 93%. The web service built on top of the graph database provides programmatic access to Reactome data by object oriented queries, but also supports more complex queries that take advantage of the new underlying graph-based data storage. By adopting graph database technology we are providing a high performance pathway data resource to the community. The Reactome graph database use case shows the power of NoSQL database engines for complex biological data types.

Reactome graph database: Efficient access to complex pathway data.

Science.gov (United States)

Fabregat, Antonio; Korninger, Florian; Viteri, Guilherme; Sidiropoulos, Konstantinos; Marin-Garcia, Pablo; Ping, Peipei; Wu, Guanming; Stein, Lincoln; D'Eustachio, Peter; Hermjakob, Henning

2018-01-01

Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. One of its main priorities is to provide easy and efficient access to its high quality curated data. At present, biological pathway databases typically store their contents in relational databases. This limits access efficiency because there are performance issues associated with queries traversing highly interconnected data. The same data in a graph database can be queried more efficiently. Here we present the rationale behind the adoption of a graph database (Neo4j) as well as the new ContentService (REST API) that provides access to these data. The Neo4j graph database and its query language, Cypher, provide efficient access to the complex Reactome data model, facilitating easy traversal and knowledge discovery. The adoption of this technology greatly improved query efficiency, reducing the average query time by 93%. The web service built on top of the graph database provides programmatic access to Reactome data by object oriented queries, but also supports more complex queries that take advantage of the new underlying graph-based data storage. By adopting graph database technology we are providing a high performance pathway data resource to the community. The Reactome graph database use case shows the power of NoSQL database engines for complex biological data types.

Does linear separability really matter? Complex visual search is explained by simple search

Science.gov (United States)

Vighneshvel, T.; Arun, S. P.

2013-01-01

Visual search in real life involves complex displays with a target among multiple types of distracters, but in the laboratory, it is often tested using simple displays with identical distracters. Can complex search be understood in terms of simple searches? This link may not be straightforward if complex search has emergent properties. One such property is linear separability, whereby search is hard when a target cannot be separated from its distracters using a single linear boundary. However, evidence in favor of linear separability is based on testing stimulus configurations in an external parametric space that need not be related to their true perceptual representation. We therefore set out to assess whether linear separability influences complex search at all. Our null hypothesis was that complex search performance depends only on classical factors such as target-distracter similarity and distracter homogeneity, which we measured using simple searches. Across three experiments involving a variety of artificial and natural objects, differences between linearly separable and nonseparable searches were explained using target-distracter similarity and distracter heterogeneity. Further, simple searches accurately predicted complex search regardless of linear separability (r = 0.91). Our results show that complex search is explained by simple search, refuting the widely held belief that linear separability influences visual search. PMID:24029822

Effects of emotional tone and visual complexity on processing health information in prescription drug advertising.

Science.gov (United States)

Norris, Rebecca L; Bailey, Rachel L; Bolls, Paul D; Wise, Kevin R

2012-01-01

This experiment explored how the emotional tone and visual complexity of direct-to-consumer (DTC) drug advertisements affect the encoding and storage of specific risk and benefit statements about each of the drugs in question. Results are interpreted under the limited capacity model of motivated mediated message processing framework. Findings suggest that DTC drug ads should be pleasantly toned and high in visual complexity in order to maximize encoding and storage of risk and benefit information.

Visual perception of complex shape-transforming processes.

Science.gov (United States)

Schmidt, Filipp; Fleming, Roland W

2016-11-01

Morphogenesis-or the origin of complex natural form-has long fascinated researchers from practically every branch of science. However, we know practically nothing about how we perceive and understand such processes. Here, we measured how observers visually infer shape-transforming processes. Participants viewed pairs of objects ('before' and 'after' a transformation) and identified points that corresponded across the transformation. This allowed us to map out in spatial detail how perceived shape and space were affected by the transformations. Participants' responses were strikingly accurate and mutually consistent for a wide range of non-rigid transformations including complex growth-like processes. A zero-free-parameter model based on matching and interpolating/extrapolating the positions of high-salience contour features predicts the data surprisingly well, suggesting observers infer spatial correspondences relative to key landmarks. Together, our findings reveal the operation of specific perceptual organization processes that make us remarkably adept at identifying correspondences across complex shape-transforming processes by using salient object features. We suggest that these abilities, which allow us to parse and interpret the causally significant features of shapes, are invaluable for many tasks that involve 'making sense' of shape. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Learning about Complex Multi-Stakeholder Issues: Assessing the Visual Problem Appraisal

NARCIS (Netherlands)

Witteveen, L.M.; Put, M.; Leeuwis, C.

2010-01-01

This paper presents an evaluation of the visual problem appraisal (VPA) learning environment in higher education. The VPA has been designed for the training of competences that are required in complex stakeholder settings in relation to sustainability issues. The design of VPA incorporates a

The effects of two types of sleep deprivation on visual working memory capacity and filtering efficiency.

Science.gov (United States)

Drummond, Sean P A; Anderson, Dane E; Straus, Laura D; Vogel, Edward K; Perez, Veronica B

2012-01-01

Sleep deprivation has adverse consequences for a variety of cognitive functions. The exact effects of sleep deprivation, though, are dependent upon the cognitive process examined. Within working memory, for example, some component processes are more vulnerable to sleep deprivation than others. Additionally, the differential impacts on cognition of different types of sleep deprivation have not been well studied. The aim of this study was to examine the effects of one night of total sleep deprivation and 4 nights of partial sleep deprivation (4 hours in bed/night) on two components of visual working memory: capacity and filtering efficiency. Forty-four healthy young adults were randomly assigned to one of the two sleep deprivation conditions. All participants were studied: 1) in a well-rested condition (following 6 nights of 9 hours in bed/night); and 2) following sleep deprivation, in a counter-balanced order. Visual working memory testing consisted of two related tasks. The first measured visual working memory capacity and the second measured the ability to ignore distractor stimuli in a visual scene (filtering efficiency). Results showed neither type of sleep deprivation reduced visual working memory capacity. Partial sleep deprivation also generally did not change filtering efficiency. Total sleep deprivation, on the other hand, did impair performance in the filtering task. These results suggest components of visual working memory are differentially vulnerable to the effects of sleep deprivation, and different types of sleep deprivation impact visual working memory to different degrees. Such findings have implications for operational settings where individuals may need to perform with inadequate sleep and whose jobs involve receiving an array of visual information and discriminating the relevant from the irrelevant prior to making decisions or taking actions (e.g., baggage screeners, air traffic controllers, military personnel, health care providers).

The effects of two types of sleep deprivation on visual working memory capacity and filtering efficiency.

Directory of Open Access Journals (Sweden)

Sean P A Drummond

Full Text Available Sleep deprivation has adverse consequences for a variety of cognitive functions. The exact effects of sleep deprivation, though, are dependent upon the cognitive process examined. Within working memory, for example, some component processes are more vulnerable to sleep deprivation than others. Additionally, the differential impacts on cognition of different types of sleep deprivation have not been well studied. The aim of this study was to examine the effects of one night of total sleep deprivation and 4 nights of partial sleep deprivation (4 hours in bed/night on two components of visual working memory: capacity and filtering efficiency. Forty-four healthy young adults were randomly assigned to one of the two sleep deprivation conditions. All participants were studied: 1 in a well-rested condition (following 6 nights of 9 hours in bed/night; and 2 following sleep deprivation, in a counter-balanced order. Visual working memory testing consisted of two related tasks. The first measured visual working memory capacity and the second measured the ability to ignore distractor stimuli in a visual scene (filtering efficiency. Results showed neither type of sleep deprivation reduced visual working memory capacity. Partial sleep deprivation also generally did not change filtering efficiency. Total sleep deprivation, on the other hand, did impair performance in the filtering task. These results suggest components of visual working memory are differentially vulnerable to the effects of sleep deprivation, and different types of sleep deprivation impact visual working memory to different degrees. Such findings have implications for operational settings where individuals may need to perform with inadequate sleep and whose jobs involve receiving an array of visual information and discriminating the relevant from the irrelevant prior to making decisions or taking actions (e.g., baggage screeners, air traffic controllers, military personnel, health care

Efficient in-situ visualization of unsteady flows in climate simulation

Science.gov (United States)

Vetter, Michael; Olbrich, Stephan

2017-04-01

The simulation of climate data tends to produce very large data sets, which hardly can be processed in classical post-processing visualization applications. Typically, the visualization pipeline consisting of the processes data generation, visualization mapping and rendering is distributed into two parts over the network or separated via file transfer. Within most traditional post-processing scenarios the simulation is done on a supercomputer whereas the data analysis and visualization is done on a graphics workstation. That way temporary data sets with huge volume have to be transferred over the network, which leads to bandwidth bottlenecks and volume limitations. The solution to this issue is the avoidance of temporary storage, or at least significant reduction of data complexity. Within the Climate Visualization Lab - as part of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP) at the University of Hamburg, in cooperation with the German Climate Computing Center (DKRZ) - we develop and integrate an in-situ approach. Our software framework DSVR is based on the separation of the process chain between the mapping and the rendering processes. It couples the mapping process directly to the simulation by calling methods of a parallelized data extraction library, which create a time-based sequence of geometric 3D scenes. This sequence is stored on a special streaming server with an interactive post-filtering option and then played-out asynchronously in a separate 3D viewer application. Since the rendering is part of this viewer application, the scenes can be navigated interactively. In contrast to other in-situ approaches where 2D images are created as part of the simulation or synchronous co-visualization takes place, our method supports interaction in 3D space and in time, as well as fixed frame rates. To integrate in-situ processing based on our DSVR framework and methods in the ICON climate model, we are continuously evolving

Building University Capacity to Visualize Solutions to Complex Problems in the Arctic

Science.gov (United States)

Broderson, D.; Veazey, P.; Raymond, V. L.; Kowalski, K.; Prakash, A.; Signor, B.

2016-12-01

Rapidly changing environments are creating complex problems across the globe, which are particular magnified in the Arctic. These worldwide challenges can best be addressed through diverse and interdisciplinary research teams. It is incumbent on such teams to promote co-production of knowledge and data-driven decision-making by identifying effective methods to communicate their findings and to engage with the public. Decision Theater North (DTN) is a new semi-immersive visualization system that provides a space for teams to collaborate and develop solutions to complex problems, relying on diverse sets of skills and knowledge. It provides a venue to synthesize the talents of scientists, who gather information (data); modelers, who create models of complex systems; artists, who develop visualizations; communicators, who connect and bridge populations; and policymakers, who can use the visualizations to develop sustainable solutions to pressing problems. The mission of Decision Theater North is to provide a cutting-edge visual environment to facilitate dialogue and decision-making by stakeholders including government, industry, communities and academia. We achieve this mission by adopting a multi-faceted approach reflected in the theater's design, technology, networking capabilities, user support, community relationship building, and strategic partnerships. DTN is a joint project of Alaska's National Science Foundation Experimental Program to Stimulate Competitive Research (NSF EPSCoR) and the University of Alaska Fairbanks (UAF), who have brought the facility up to full operational status and are now expanding its development space to support larger team science efforts. Based in Fairbanks, Alaska, DTN is uniquely poised to address changes taking place in the Arctic and subarctic, and is connected with a larger network of decision theaters that include the Arizona State University Decision Theater Network and the McCain Institute in Washington, DC.

The Ultra-scale Visualization Climate Data Analysis Tools (UV-CDAT): Data Analysis and Visualization for Geoscience Data

Energy Technology Data Exchange (ETDEWEB)

Williams, Dean [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doutriaux, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Patchett, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Sean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shipman, Galen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Ross [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Steed, Chad [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Krishnan, Harinarayan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Silva, Claudio [NYU Polytechnic School of Engineering, New York, NY (United States); Chaudhary, Aashish [Kitware, Inc., Clifton Park, NY (United States); Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pugmire, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Childs, Hank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prabhat, Mr. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geveci, Berk [Kitware, Inc., Clifton Park, NY (United States); Bauer, Andrew [Kitware, Inc., Clifton Park, NY (United States); Pletzer, Alexander [Tech-X Corp., Boulder, CO (United States); Poco, Jorge [NYU Polytechnic School of Engineering, New York, NY (United States); Ellqvist, Tommy [NYU Polytechnic School of Engineering, New York, NY (United States); Santos, Emanuele [Federal Univ. of Ceara, Fortaleza (Brazil); Potter, Gerald [NASA Johnson Space Center, Houston, TX (United States); Smith, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Maxwell, Thomas [NASA Johnson Space Center, Houston, TX (United States); Kindig, David [Tech-X Corp., Boulder, CO (United States); Koop, David [NYU Polytechnic School of Engineering, New York, NY (United States)

2013-05-01

To support interactive visualization and analysis of complex, large-scale climate data sets, UV-CDAT integrates a powerful set of scientific computing libraries and applications to foster more efficient knowledge discovery. Connected through a provenance framework, the UV-CDAT components can be loosely coupled for fast integration or tightly coupled for greater functionality and communication with other components. This framework addresses many challenges in the interactive visual analysis of distributed large-scale data for the climate community.

Efficient analysis using custom interactive visualization tools at a Superfund site

International Nuclear Information System (INIS)

Williams, G.; Durham, L.

1992-01-01

Custom visualization analysis programs were developed and used to analyze contaminant transport calculations from a three-dimensional numerical groundwater flow model developed for a Department of Energy Superfund site. The site hydrogeology, which is highly heterogenous, includes both fractured limestone and dolomite and alluvium deposits. Three-dimensional interactive visualization techniques were used to understand and analyze the three-dimensional, double-porosity modeling results. A graphical object oriented programming environment was applied to efficiently develop custom visualization programs in a coarse-grained data structure language. Comparisons were made, using the results from the three-dimensional, finite-difference model, between traditional two-dimensional analyses (contour and vector plots) and interactive three-dimensional techniques. Subjective comparison areas include the accuracy of analysis, the ability to understand the results of three-dimensional contaminant transport simulation, and the capability to transmit the results of the analysis to the project management. In addition, a quantitative comparison was made on the time required to develop a thorough analysis of the modeling results. The conclusions from the comparative study showed that the visualization analysis provided an increased awareness of the contaminant transport mechanisms, provided new insights into contaminant migration, and resulted in a significant time savings

Efficient analysis using custom interactive visualization tools at a Superfund site

Energy Technology Data Exchange (ETDEWEB)

Williams, G. [Northwestern Univ., Evanston, IL (United States); Durham, L. [Argonne National Lab., IL (United States)

1992-12-01

Custom visualization analysis programs were developed and used to analyze contaminant transport calculations from a three-dimensional numerical groundwater flow model developed for a Department of Energy Superfund site. The site hydrogeology, which is highly heterogenous, includes both fractured limestone and dolomite and alluvium deposits. Three-dimensional interactive visualization techniques were used to understand and analyze the three-dimensional, double-porosity modeling results. A graphical object oriented programming environment was applied to efficiently develop custom visualization programs in a coarse-grained data structure language. Comparisons were made, using the results from the three-dimensional, finite-difference model, between traditional two-dimensional analyses (contour and vector plots) and interactive three-dimensional techniques. Subjective comparison areas include the accuracy of analysis, the ability to understand the results of three-dimensional contaminant transport simulation, and the capability to transmit the results of the analysis to the project management. In addition, a quantitative comparison was made on the time required to develop a thorough analysis of the modeling results. The conclusions from the comparative study showed that the visualization analysis provided an increased awareness of the contaminant transport mechanisms, provided new insights into contaminant migration, and resulted in a significant time savings.

Picture norms for Chinese preschool children: name agreement, familiarity, and visual complexity.

Directory of Open Access Journals (Sweden)

Lamei Wang

Full Text Available Pictorial stimuli standardized for Chinese children are still absent although it is needed in order to test the development of children's cognitive functions. This study presents normative measures for Snodgrass and Vanderwart pictures, viewed by 4- and 6-year old Chinese children. Name agreement, familiarity, and visual complexity were obtained for each age group. The data indicate substantial differences between young and older children in name agreement based on expected name, familiarity and visual complexity. The correlation pattern of the variables collected in the present study were consistent with children's norms in other languages and norms of Chinese adults, while there are cross-age and cross-culture differences in specific variables. The obtained measures represent a useful tool for further research on Chinese children's pictorial processing and constitute the first picture normative study for children in this language.

Guidance of visual search by memory and knowledge.

Science.gov (United States)

Hollingworth, Andrew

2012-01-01

To behave intelligently in the world, humans must be able to find objects efficiently within the complex environments they inhabit. A growing proportion of the literature on visual search is devoted to understanding this type of natural search. In the present chapter, I review the literature on visual search through natural scenes, focusing on the role of memory and knowledge in guiding attention to task-relevant objects.

Perceptual Dependencies in Information Visualization Assessed by Complex Visual Search

NARCIS (Netherlands)

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

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

The Study of Learners' Preference for Visual Complexity on Small Screens of Mobile Computers Using Neural Networks

Science.gov (United States)

Wang, Lan-Ting; Lee, Kun-Chou

2014-01-01

The vision plays an important role in educational technologies because it can produce and communicate quite important functions in teaching and learning. In this paper, learners' preference for the visual complexity on small screens of mobile computers is studied by neural networks. The visual complexity in this study is divided into five…

Exploring the morphospace of communication efficiency in complex networks.

Directory of Open Access Journals (Sweden)

Joaquín Goñi

Full Text Available Graph theoretical analysis has played a key role in characterizing global features of the topology of complex networks, describing diverse systems such as protein interactions, food webs, social relations and brain connectivity. How system elements communicate with each other depends not only on the structure of the network, but also on the nature of the system's dynamics which are constrained by the amount of knowledge and resources available for communication processes. Complementing widely used measures that capture efficiency under the assumption that communication preferentially follows shortest paths across the network ("routing", we define analytic measures directed at characterizing network communication when signals flow in a random walk process ("diffusion". The two dimensions of routing and diffusion efficiency define a morphospace for complex networks, with different network topologies characterized by different combinations of efficiency measures and thus occupying different regions of this space. We explore the relation of network topologies and efficiency measures by examining canonical network models, by evolving networks using a multi-objective optimization strategy, and by investigating real-world network data sets. Within the efficiency morphospace, specific aspects of network topology that differentially favor efficient communication for routing and diffusion processes are identified. Charting regions of the morphospace that are occupied by canonical, evolved or real networks allows inferences about the limits of communication efficiency imposed by connectivity and dynamics, as well as the underlying selection pressures that have shaped network topology.

Communication and Energy Efficiency in Visual Sensor Networks for People Localization

Energy Technology Data Exchange (ETDEWEB)

Karakaya, Mahmut [ORNL; Qi, Hairong [ORNL

2012-01-01

This paper addresses the communication and energy efficiency in collaborative visual sensor networks (VSNs) for people localization, a challenging computer vision problem of its own. We focus on the design of a light-weight and energy efficient solution where people are localized based on distributed camera nodes integrating the so-called certainty map generated at each node, that records the target non-existence information within the camera s field of view. We first present a dynamic itinerary for certainty map integration where not only each sensor node transmits a very limited amount of data but that a limited number of camera nodes is involved. Then, we perform a comprehensive analytical study to evaluate communication and energy efficiency between different integration schemes, i.e., centralized and distributed integration. Based on results obtained from analytical study and real experiments, the distributed method shows effectiveness in detection accuracy as well as energy and bandwidth efficiency.

Visualizing Contour Trees within Histograms

DEFF Research Database (Denmark)

Kraus, Martin

2010-01-01

Many of the topological features of the isosurfaces of a scalar volume field can be compactly represented by its contour tree. Unfortunately, the contour trees of most real-world volume data sets are too complex to be visualized by dot-and-line diagrams. Therefore, we propose a new visualization...... that is suitable for large contour trees and efficiently conveys the topological structure of the most important isosurface components. This visualization is integrated into a histogram of the volume data; thus, it offers strictly more information than a traditional histogram. We present algorithms...... to automatically compute the graph layout and to calculate appropriate approximations of the contour tree and the surface area of the relevant isosurface components. The benefits of this new visualization are demonstrated with the help of several publicly available volume data sets....

Efficiency and effectiveness in case of disaster: a visual damage assessment test

Science.gov (United States)

Ooms, Kristien; Åhlén, Julia; Seipel, Stefan

2018-05-01

A user study is conducted to evaluate the efficiency and effectiveness of two types of visualizations to identify damages sites in case of disaster. The test consists out 36 trials (18 for each visualisation) and in each trial an area of 1 × 1 km, located in Ghent, is displayed on a screen. This image shows the combined height information from before and after the disaster. The first visualisation, page flipping, is based on greyscale images with height information from the pre- and post-disaster situation between which users can switch manually. The second visualisation, difference image, is a result of subtracting the heights (before versus after) and assigning a blue-white-red colour ramp. In order to simulate the urgency with which the data is captured, systematic and random imperfections are introduced in the post-disaster data. All participants' mouse and key interactions are logged, which is further complemented by the registration of their eye movements. This give insights the visualizations' efficiency, effectiveness and the overall search strategies of the participants.

Real-Time Agent-Based Modeling Simulation with in-situ Visualization of Complex Biological Systems: A Case Study on Vocal Fold Inflammation and Healing.

Science.gov (United States)

Seekhao, Nuttiiya; Shung, Caroline; JaJa, Joseph; Mongeau, Luc; Li-Jessen, Nicole Y K

2016-05-01

We present an efficient and scalable scheme for implementing agent-based modeling (ABM) simulation with In Situ visualization of large complex systems on heterogeneous computing platforms. The scheme is designed to make optimal use of the resources available on a heterogeneous platform consisting of a multicore CPU and a GPU, resulting in minimal to no resource idle time. Furthermore, the scheme was implemented under a client-server paradigm that enables remote users to visualize and analyze simulation data as it is being generated at each time step of the model. Performance of a simulation case study of vocal fold inflammation and wound healing with 3.8 million agents shows 35× and 7× speedup in execution time over single-core and multi-core CPU respectively. Each iteration of the model took less than 200 ms to simulate, visualize and send the results to the client. This enables users to monitor the simulation in real-time and modify its course as needed.

Energetic efficiency of complex substrate utilization by Trichoderma viride

Energy Technology Data Exchange (ETDEWEB)

Leite, M; Apine, A; Zeltina, M; Shvinka, J [AN Latvijskoj SSR, Riga (USSR). August Kirchstein Inst. of Microbiology

1989-01-01

The efficiency of carbon substrate utilization is evaluated as the thermodynamic efficiency (eta{sub x}) of microbial growth. Three methods based on mass-energy balance are used for the efficiency studies of complex substrates (straw, plant juices, lye) utilization by microfungi Trichoderma viride. 1. According to substrate and biomass balance eta{sub x}=0.55, 0.37 and 0.36 for Trichoderma viride growth on alkali pretreated wheat straw during 23, 34 and 50 hours. Cellulose biodegradation increases with cultivation time. However, the efficiency of cellulose utilization for cell mass growth decreases at the same time. 2. In accordance with oxygen-balance calculations eta{sub x}=0.75 and 0.71 for the same processes. The discrepancy in results from the above two methods probably can be explained by the following: A. Substrate and biomass balance gives underestimated results. B. Oxygen balance method includes the part of energy for extracellular product formation and therefore eta{sub x} can be overestimated. C. The efficiency of complex soluble substrate utilization (lye, green juice, deproteinized brown plant juice) tested by means of pulse method gives the values of eta{sub x}=0.72-0.88. Similar high estimates of eta{sub x} in C-limited batch culture are observed for soluble carbohydrates (glucose, galactose, lactose, xylose) but not for acetate. The pulse method is advantageous for testing the 'true' efficiency of carbon substrate utilization in a definite physiological environment. (orig.).

Visual comparison for information visualization

KAUST Repository

Gleicher, M.; Albers, D.; Walker, R.; Jusufi, I.; Hansen, C. D.; Roberts, J. C.

2011-01-01

Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

Visual comparison for information visualization

KAUST Repository

Gleicher, M.

2011-09-07

Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

Low complexity wireless sensors for power-efficient communiation and energy harvesting

DEFF Research Database (Denmark)

Bo, Han

large antenna spacing and additional RF chains hinder its application to compact and battery powered devices. Wireless sensor networks are composed of such battery-powered devices, which require better energy efficiency in order to have a longer lifetime. Thus low complexity wireless sensors for power......The modern communication goes towards the direction of green, sustainable solutions; this raises many issues such as better usage of spectrum, lower system complexity, or lower energy consumption. MIMO transmission provides a promising solution with better spectral efficiency, but the required...... efficient communications are necessary. The beam space MIMO transmission approach was proposed recently for energy efficient communication; it uses only one RF chain and maps the MIMO data streams onto orthogonal basis radiation patterns. The resulting data streams appear at the receiver as originating from...

Memory for Complex Visual Objects but Not for Allocentric Locations during the First Year of Life

Science.gov (United States)

Dupierrix, Eve; Hillairet de Boisferon, Anne; Barbeau, Emmanuel; Pascalis, Olivier

2015-01-01

Although human infants demonstrate early competence to retain visual information, memory capacities during infancy remain largely undocumented. In three experiments, we used a Visual Paired Comparison (VPC) task to examine abilities to encode identity (Experiment 1) and spatial properties (Experiments 2a and 2b) of unfamiliar complex visual…

Learning Science in a Virtual Reality Application: The Impacts of Animated-Virtual Actors' Visual Complexity

Science.gov (United States)

Kartiko, Iwan; Kavakli, Manolya; Cheng, Ken

2010-01-01

As the technology in computer graphics advances, Animated-Virtual Actors (AVAs) in Virtual Reality (VR) applications become increasingly rich and complex. Cognitive Theory of Multimedia Learning (CTML) suggests that complex visual materials could hinder novice learners from attending to the lesson properly. On the other hand, previous studies have…

INDICATORS OF EFFICIENCY OF THE PILOTLESS AVIATION COMPLEX

Directory of Open Access Journals (Sweden)

A. S. Benkafo

2014-01-01

Full Text Available The general principles of an estimation of efficiency of application of pilotless aviation complexes are considered at monitoring of a terrestrial surface in the conditions of presence of unauthenticity of the information on the basis of mathematical  modelling  with  the  account  of  hierarchical  construction  and  influence of  the  human  factor.  The substantiation of indicators of efficiency of information system and likelihood characteristics of an estimation of the information necessary for decision-making is spent.

Seeing the forest through the trees: uncovering phenomic complexity through interactive network visualization.

Science.gov (United States)

Warner, Jeremy L; Denny, Joshua C; Kreda, David A; Alterovitz, Gil

2015-03-01

Our aim was to uncover unrecognized phenomic relationships using force-based network visualization methods, based on observed electronic medical record data. A primary phenotype was defined from actual patient profiles in the Multiparameter Intelligent Monitoring in Intensive Care II database. Network visualizations depicting primary relationships were compared to those incorporating secondary adjacencies. Interactivity was enabled through a phenotype visualization software concept: the Phenomics Advisor. Subendocardial infarction with cardiac arrest was demonstrated as a sample phenotype; there were 332 primarily adjacent diagnoses, with 5423 relationships. Primary network visualization suggested a treatment-related complication phenotype and several rare diagnoses; re-clustering by secondary relationships revealed an emergent cluster of smokers with the metabolic syndrome. Network visualization reveals phenotypic patterns that may have remained occult in pairwise correlation analysis. Visualization of complex data, potentially offered as point-of-care tools on mobile devices, may allow clinicians and researchers to quickly generate hypotheses and gain deeper understanding of patient subpopulations. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex.

Science.gov (United States)

Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I; Tao, Huizhong W

2015-08-05

In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity

Impact of the motion and visual complexity of the background on players' performance in video game-like displays.

Science.gov (United States)

Caroux, Loïc; Le Bigot, Ludovic; Vibert, Nicolas

2013-01-01

The visual interfaces of virtual environments such as video games often show scenes where objects are superimposed on a moving background. Three experiments were designed to better understand the impact of the complexity and/or overall motion of two types of visual backgrounds often used in video games on the detection and use of superimposed, stationary items. The impact of background complexity and motion was assessed during two typical video game tasks: a relatively complex visual search task and a classic, less demanding shooting task. Background motion impaired participants' performance only when they performed the shooting game task, and only when the simplest of the two backgrounds was used. In contrast, and independently of background motion, performance on both tasks was impaired when the complexity of the background increased. Eye movement recordings demonstrated that most of the findings reflected the impact of low-level features of the two backgrounds on gaze control.

Correlations of visual scores, carcass traits, feed efficiency and retail product yield in Nellore cattle

Directory of Open Access Journals (Sweden)

Paulo Henrique Cancian

2014-02-01

Full Text Available The growing use of visual scores (VS and ultrasound (US for carcass evaluation in breeding programs, calls for a knowledge of the relationships between these traits and other relevant characteristics, such as feed efficiency and production of commercial cuts. The objective of this study was to evaluate correlations between body visual scores and carcass traits identified by ultrasound (US and feed efficiency (FE, carcass weight (HCW, dressing percentage (DP and retail product yield (RPY in beef cattle. Nellore cattle (male, 42 non-castrated [NCAST] and 44 castrated [CAST] were evaluated by both VS and US, at the postweaning (15-month old and finishing phases (21-month old. Visual scores of conformation (C, precocity (P and muscling (M were assessed and the backfat thickness (UBFT, rump fat thickness (URFT and ribeye area (UREA were measured by ultrasound. Gain-to-feed (G:F ratio and residual feed intake (RFI were measured in feedlot. Hot carcass weight, DP and RPY were determined at harvest. Non-castrated cattle had greater HCW and RPY but lower UBFT and URFT than CAST. Postweaning VS and US were poorly correlated with FE in both sexual conditions. Finishing VS were negatively correlated with G:F in CAST and finishing URFT was negatively correlated with RPY in NCAST. The relationship of VS and US with feed efficiency and meat yield is affected by age at the date of evaluation and by castration. Feed efficiency is not related to the yield of meat cuts in Nellore cattle

Visual Working Memory Capacity Can Be Increased by Training on Distractor Filtering Efficiency.

Science.gov (United States)

Li, Cui-Hong; He, Xu; Wang, Yu-Juan; Hu, Zhe; Guo, Chun-Yan

2017-01-01

It is generally considered that working memory (WM) capacity is limited and that WM capacity affects cognitive processes. Distractor filtering efficiency has been suggested to be an important factor in determining the visual working memory (VWM) capacity of individuals. In the present study, we investigated whether training in visual filtering efficiency (FE) could improve VWM capacity, as measured by performance on the change detection task (CDT) and changes of contralateral delay activity (CDA) (contralateral delay activity) of different conditions, and evaluated the transfer effect of visual FE training on verbal WM and fluid intelligence, as indexed by performance on the verbal WM span task and Raven's Standard Progressive Matrices (RSPM) test, respectively. Participants were divided into high- and low-capacity groups based on their performance in a CDT designed to test VWM capacity, and then the low-capacity individuals received 20 days of FE training. The training significantly improved the group's performance in the CDT, and their CDA models of different conditions became more similar with high capacity group, and the effect generalized to improve verbal WM span. These gains were maintained at a 3-month follow-up test. Participants' RSPM scores were not changed by the training. These findings support the notion that WM capacity is determined, at least in part, by distractor FE and can be enhanced through training.

Interactive Visual Analysis for Organic Photovoltaic Solar Cells

KAUST Repository

Abouelhassan, Amal A.

2017-12-05

Organic Photovoltaic (OPV) solar cells provide a promising alternative for harnessing solar energy. However, the efficient design of OPV materials that achieve better performance requires support by better-tailored visualization tools than are currently available, which is the goal of this thesis. One promising approach in the OPV field is to control the effective material of the OPV device, which is known as the Bulk-Heterojunction (BHJ) morphology. The BHJ morphology has a complex composition. Current BHJ exploration techniques deal with the morphologies as black boxes with no perception of the photoelectric current in the BHJ morphology. Therefore, this method depends on a trial-and-error approach and does not efficiently characterize complex BHJ morphologies. On the other hand, current state-of-the-art methods for assessing the performance of BHJ morphologies are based on the global quantification of morphological features. Accordingly, scientists in OPV research are still lacking a sufficient understanding of the best material design. To remove these limitations, we propose a new approach for knowledge-assisted visual exploration and analysis in the OPV domain. We develop new techniques for enabling efficient OPV charge transport path analysis. We employ, adapt, and develop techniques from scientific visualization, geometric modeling, clustering, and visual interaction to obtain new designs of visualization tools that are specifically tailored for the needs of OPV scientists. At the molecular scale, the user can use semantic rules to define clusters of atoms with certain geometric properties. At the nanoscale, we propose a novel framework for visual characterization and exploration of local structure-performance correlations. We also propose a new approach for correlating structural features to performance bottlenecks. We employ a visual feedback strategy that allows scientists to make intuitive choices about fabrication parameters. We furthermore propose a

Efficient transmission of compressed data for remote volume visualization.

Science.gov (United States)

Krishnan, Karthik; Marcellin, Michael W; Bilgin, Ali; Nadar, Mariappan S

2006-09-01

One of the goals of telemedicine is to enable remote visualization and browsing of medical volumes. There is a need to employ scalable compression schemes and efficient client-server models to obtain interactivity and an enhanced viewing experience. First, we present a scheme that uses JPEG2000 and JPIP (JPEG2000 Interactive Protocol) to transmit data in a multi-resolution and progressive fashion. The server exploits the spatial locality offered by the wavelet transform and packet indexing information to transmit, in so far as possible, compressed volume data relevant to the clients query. Once the client identifies its volume of interest (VOI), the volume is refined progressively within the VOI from an initial lossy to a final lossless representation. Contextual background information can also be made available having quality fading away from the VOI. Second, we present a prioritization that enables the client to progressively visualize scene content from a compressed file. In our specific example, the client is able to make requests to progressively receive data corresponding to any tissue type. The server is now capable of reordering the same compressed data file on the fly to serve data packets prioritized as per the client's request. Lastly, we describe the effect of compression parameters on compression ratio, decoding times and interactivity. We also present suggestions for optimizing JPEG2000 for remote volume visualization and volume browsing applications. The resulting system is ideally suited for client-server applications with the server maintaining the compressed volume data, to be browsed by a client with a low bandwidth constraint.

Factors influencing efficient structure of fuel and energy complex

Science.gov (United States)

Sidorova, N. G.; Novikova, S. A.

2017-10-01

The development of the Russian fuel-energy complex is a priority for the national economic policy, and the Far East is a link between Russia and the Asia-Pacific region. Large-scale engineering of numerous resources of the Far East will force industrial development, increase living standard and strengthen Russia’s position in the global energy market. So, revealing the factors which influence rational structure of the fuel-energy complex is very urgent nowadays. With the use of depth analysis of development tendencies of the complex and its problems the authors show ways of its efficiency improvement.

Community-based naming agreement, familiarity, image agreement and visual complexity ratings among adult Indians

Directory of Open Access Journals (Sweden)

George Annamma

2007-01-01

Full Text Available The validity of Snodgrass and Vanderwart pictures and their norms derived on a western population on naming, familiarity, imageability and visual-complexity, is not established on a population with cultural background different from the west. We developed, therefore, a set of culturally appropriate pictures for and derived norms on Indians. Line-drawings of 103 concepts (67 from Snodgrass and Vanderwart, 36 new from 10 semantic-categories were normed on 200 community-based older subjects. Only 31% of the Snodgrass and Vanderwart items showed a concept-agreement on the Indians comparable to western norms. Naming, familiarity and image-agreement mutually correlated but not with visual-complexity. Low-education and rural-residence tended to reduced concept-agreement. The output of this study will be of use in national and cross-national studies.

Remote sensing image ship target detection method based on visual attention model

Science.gov (United States)

Sun, Yuejiao; Lei, Wuhu; Ren, Xiaodong

2017-11-01

The traditional methods of detecting ship targets in remote sensing images mostly use sliding window to search the whole image comprehensively. However, the target usually occupies only a small fraction of the image. This method has high computational complexity for large format visible image data. The bottom-up selective attention mechanism can selectively allocate computing resources according to visual stimuli, thus improving the computational efficiency and reducing the difficulty of analysis. Considering of that, a method of ship target detection in remote sensing images based on visual attention model was proposed in this paper. The experimental results show that the proposed method can reduce the computational complexity while improving the detection accuracy, and improve the detection efficiency of ship targets in remote sensing images.

The difference in subjective and objective complexity in the visual short-term memory

DEFF Research Database (Denmark)

Dall, Jonas Olsen; Sørensen, Thomas Alrik

Several studies discuss the influence of complexity on the visual short term memory; some have demonstrated that short-term memory is surprisingly stable regardless of content (e.g. Luck & Vogel, 1997) where others have shown that memory can be influenced by the complexity of stimulus (e.g. Alvarez...... characters. On the contrary expertise or word frequency may reflect what could be termed subjective complexity, as this relate directly to the individual mental categories established. This study will be able to uncover more details on how we should define complexity of objects to be encoded into short-term....... & Cavanagh, 2004). But the term complexity is often not clearly defined. Sørensen (2008; see also Dall, Katsumi, & Sørensen, 2016) suggested that complexity can be related to two different types; objective and subjective complexity. This distinction is supported by a number of studies on the influence...

Visualization of complex DNA damage along accelerated ions tracks

Science.gov (United States)

Kulikova, Elena; Boreyko, Alla; Bulanova, Tatiana; Ježková, Lucie; Zadneprianetc, Mariia; Smirnova, Elena

2018-04-01

The most deleterious DNA lesions induced by ionizing radiation are clustered DNA double-strand breaks (DSB). Clustered or complex DNA damage is a combination of a few simple lesions (single-strand breaks, base damage etc.) within one or two DNA helix turns. It is known that yield of complex DNA lesions increases with increasing linear energy transfer (LET) of radiation. For investigation of the induction and repair of complex DNA lesions, human fibroblasts were irradiated with high-LET 15N ions (LET = 183.3 keV/μm, E = 13MeV/n) and low-LET 60Co γ-rays (LET ≈ 0.3 keV/μm) radiation. DNA DSBs (γH2AX and 53BP1) and base damage (OGG1) markers were visualized by immunofluorecence staining and high-resolution microscopy. The obtained results showed slower repair kinetics of induced DSBs in cells irradiated with accelerated ions compared to 60Co γ-rays, indicating induction of more complex DNA damage. Confirming previous assumptions, detailed 3D analysis of γH2AX/53BP1 foci in 15N ions tracks revealed more complicated structure of the foci in contrast to γ-rays. It was shown that proteins 53BP1 and OGG1 involved in repair of DNA DSBs and modified bases, respectively, were colocalized in tracks of 15N ions and thus represented clustered DNA DSBs.

Methodology for the Efficient Progressive Distribution and Visualization of 3D Building Objects

Directory of Open Access Journals (Sweden)

Bo Mao

2016-10-01

Full Text Available Three-dimensional (3D, city models have been applied in a variety of fields. One of the main problems in 3D city model utilization, however, is the large volume of data. In this paper, a method is proposed to generalize the 3D building objects in 3D city models at different levels of detail, and to combine multiple Levels of Detail (LODs for a progressive distribution and visualization of the city models. First, an extended structure for multiple LODs of building objects, BuildingTree, is introduced that supports both single buildings and building groups; second, constructive solid geometry (CSG representations of buildings are created and generalized. Finally, the BuildingTree is stored in the NoSQL database MongoDB for dynamic visualization requests. The experimental results indicate that the proposed progressive method can efficiently visualize 3D city models, especially for large areas.

The effects of action video game experience on the time course of inhibition of return and the efficiency of visual search.

Science.gov (United States)

Castel, Alan D; Pratt, Jay; Drummond, Emily

2005-06-01

The ability to efficiently search the visual environment is a critical function of the visual system, and recent research has shown that experience playing action video games can influence visual selective attention. The present research examined the similarities and differences between video game players (VGPs) and non-video game players (NVGPs) in terms of the ability to inhibit attention from returning to previously attended locations, and the efficiency of visual search in easy and more demanding search environments. Both groups were equally good at inhibiting the return of attention to previously cued locations, although VGPs displayed overall faster reaction times to detect targets. VGPs also showed overall faster response time for easy and difficult visual search tasks compared to NVGPs, largely attributed to faster stimulus-response mapping. The findings suggest that relative to NVGPs, VGPs rely on similar types of visual processing strategies but possess faster stimulus-response mappings in visual attention tasks.

Efficient light-emitting devices based on platinum-complexes-anchored polyhedral oligomeric silsesquioxane materials

KAUST Repository

Yang, Xiaohui

2010-08-24

The synthesis, photophysical, and electrochemical characterization of macromolecules, consisting of an emissive platinum complex and carbazole moieties covalently attached to a polyhedral oligomeric silsesquioxane (POSS) core, is reported. Organic light-emitting devices based on these POSS materials exhibit a peak external quantum efficiency of ca. 8%, which is significantly higher than that of the analogous devices with a physical blend of the platinum complexes and a polymer matrix, and they represent noticeable improvement in the device efficiency of solution-processable phosphorescent excimer devices. Furthermore, the ratio of monomer and excimer/aggregate electroluminescent emission intensity, as well as the device efficiency, increases as the platinum complex moiety presence on the POSS macromolecules decreases. © 2010 American Chemical Society.

Predictive information speeds up visual awareness in an individuation task by modulating threshold setting, not processing efficiency.

Science.gov (United States)

De Loof, Esther; Van Opstal, Filip; Verguts, Tom

2016-04-01

Theories on visual awareness claim that predicted stimuli reach awareness faster than unpredicted ones. In the current study, we disentangle whether prior information about the upcoming stimulus affects visual awareness of stimulus location (i.e., individuation) by modulating processing efficiency or threshold setting. Analogous research on stimulus identification revealed that prior information modulates threshold setting. However, as identification and individuation are two functionally and neurally distinct processes, the mechanisms underlying identification cannot simply be extrapolated directly to individuation. The goal of this study was therefore to investigate how individuation is influenced by prior information about the upcoming stimulus. To do so, a drift diffusion model was fitted to estimate the processing efficiency and threshold setting for predicted versus unpredicted stimuli in a cued individuation paradigm. Participants were asked to locate a picture, following a cue that was congruent, incongruent or neutral with respect to the picture's identity. Pictures were individuated faster in the congruent and neutral condition compared to the incongruent condition. In the diffusion model analysis, the processing efficiency was not significantly different across conditions. However, the threshold setting was significantly higher following an incongruent cue compared to both congruent and neutral cues. Our results indicate that predictive information about the upcoming stimulus influences visual awareness by shifting the threshold for individuation rather than by enhancing processing efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Considerations for the composition of visual scene displays: potential contributions of information from visual and cognitive sciences.

Science.gov (United States)

Wilkinson, Krista M; Light, Janice; Drager, Kathryn

2012-09-01

Aided augmentative and alternative (AAC) interventions have been demonstrated to facilitate a variety of communication outcomes in persons with intellectual disabilities. Most aided AAC systems rely on a visual modality. When the medium for communication is visual, it seems likely that the effectiveness of intervention depends in part on the effectiveness and efficiency with which the information presented in the display can be perceived, identified, and extracted by communicators and their partners. Understanding of visual-cognitive processing - that is, how a user attends, perceives, and makes sense of the visual information on the display - therefore seems critical to designing effective aided AAC interventions. In this Forum Note, we discuss characteristics of one particular type of aided AAC display, that is, Visual Scene Displays (VSDs) as they may relate to user visual and cognitive processing. We consider three specific ways in which bodies of knowledge drawn from the visual cognitive sciences may be relevant to the composition of VSDs, with the understanding the direct research with children with complex communication needs is necessary to verify or refute our speculations.

Diphosphonic acid complexants for improved separation efficiency of transuranic elements

International Nuclear Information System (INIS)

Nash, K.L.

1994-01-01

A study was made of the thermodynamics of protonation and complexation of Eu(III), Th(IV), and U(VI) by a series of simple diphosphonic acid chelating agents to assess the potential for application in actinide waste processing. It was found that the strongest complexes are formed with ligands having two phosphonate binding groups on the same C atom (1,1-diphosphonates) and that the water-soluble complexes are formed with protonated ligand species. More efficient separation/recovery processes could be designed using these ligands

The neural basis of precise visual short-term memory for complex recognisable objects.

Science.gov (United States)

Veldsman, Michele; Mitchell, Daniel J; Cusack, Rhodri

2017-10-01

Recent evidence suggests that visual short-term memory (VSTM) capacity estimated using simple objects, such as colours and oriented bars, may not generalise well to more naturalistic stimuli. More visual detail can be stored in VSTM when complex, recognisable objects are maintained compared to simple objects. It is not yet known if it is recognisability that enhances memory precision, nor whether maintenance of recognisable objects is achieved with the same network of brain regions supporting maintenance of simple objects. We used a novel stimulus generation method to parametrically warp photographic images along a continuum, allowing separate estimation of the precision of memory representations and the number of items retained. The stimulus generation method was also designed to create unrecognisable, though perceptually matched, stimuli, to investigate the impact of recognisability on VSTM. We adapted the widely-used change detection and continuous report paradigms for use with complex, photographic images. Across three functional magnetic resonance imaging (fMRI) experiments, we demonstrated greater precision for recognisable objects in VSTM compared to unrecognisable objects. This clear behavioural advantage was not the result of recruitment of additional brain regions, or of stronger mean activity within the core network. Representational similarity analysis revealed greater variability across item repetitions in the representations of recognisable, compared to unrecognisable complex objects. We therefore propose that a richer range of neural representations support VSTM for complex recognisable objects. Copyright © 2017 Elsevier Inc. All rights reserved.

Mixed-ligand Al complex-a new approach for more high efficient OLEDs

Energy Technology Data Exchange (ETDEWEB)

Petrova, Petia K., E-mail: petia@clf.bas.bg [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Tomova, Reni L.; Stoycheva-Topalova, Rumiana T. [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Kaloyanova, Stefka S.; Deligeorgiev, Todor G. [Applied Organic Chemistry, Faculty of Chemistry, University of Sofia, Sofia 1164 (Bulgaria)

2012-02-15

The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq{sub 2}Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq{sub 3}. Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq{sub 3} The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: Black-Right-Pointing-Pointer A novel electroluminescent Alq{sub 2}Acac complex is presented as material for OLED. Black-Right-Pointing-Pointer Electroluminescent emission of Alq{sub 2}Acac is very similar to that of commercial Alq{sub 3}. Black-Right-Pointing-Pointer Devices with Alq{sub 2}Acac show better characteristics compared to those with Alq{sub 3}.

Palladium(0) NHC complexes: a new avenue to highly efficient phosphorescence.

Science.gov (United States)

Henwood, Adam F; Lesieur, Mathieu; Bansal, Ashu K; Lemaur, Vincent; Beljonne, David; Thompson, David G; Graham, Duncan; Slawin, Alexandra M Z; Samuel, Ifor D W; Cazin, Catherine S J; Zysman-Colman, Eli

2015-05-01

We report the first examples of highly luminescent di-coordinated Pd(0) complexes. Five complexes of the form [Pd(L)(L')] were synthesized, where L = IPr, SIPr or IPr* NHC ligands and L' = PCy 3 , or IPr and SIPr NHC ligands. The photophysical properties of these complexes were determined in degassed toluene solution and in the solid state and contrasted to the poorly luminescent reference complex [Pd(IPr)(PPh 3 )]. Organic light-emitting diodes were successfully fabricated but attained external quantum efficiencies of between 0.3 and 0.7%.

The Effect of Visual Stimuli on Stability and Complexity of Postural Control

Directory of Open Access Journals (Sweden)

Haizhen Luo

2018-02-01

Full Text Available Visual input could benefit balance control or increase postural sway, and it is far from fully understanding the effect of visual stimuli on postural stability and its underlying mechanism. In this study, the effect of different visual inputs on stability and complexity of postural control was examined by analyzing the mean velocity (MV, SD, and fuzzy approximate entropy (fApEn of the center of pressure (COP signal during quiet upright standing. We designed five visual exposure conditions: eyes-closed, eyes-open (EO, and three virtual reality (VR scenes (VR1–VR3. The VR scenes were a limited field view of an optokinetic drum rotating around yaw (VR1, pitch (VR2, and roll (VR3 axes, respectively. Sixteen healthy subjects were involved in the experiment, and their COP trajectories were assessed from the force plate data. MV, SD, and fApEn of the COP in anterior–posterior (AP, medial–lateral (ML directions were calculated. Two-way analysis of variance with repeated measures was conducted to test the statistical significance. We found that all the three parameters obtained the lowest values in the EO condition, and highest in the VR3 condition. We also found that the active neuromuscular intervention, indicated by fApEn, in response to changing the visual exposure conditions were more adaptive in AP direction, and the stability, indicated by SD, in ML direction reflected the changes of visual scenes. MV was found to capture both instability and active neuromuscular control dynamics. It seemed that the three parameters provided compensatory information about the postural control in the immersive virtual environment.

Efficient LBM visual simulation on face-centered cubic lattices.

Science.gov (United States)

Petkov, Kaloian; Qiu, Feng; Fan, Zhe; Kaufman, Arie E; Mueller, Klaus

2009-01-01

The Lattice Boltzmann method (LBM) for visual simulation of fluid flow generally employs cubic Cartesian (CC) lattices such as the D3Q13 and D3Q19 lattices for the particle transport. However, the CC lattices lead to suboptimal representation of the simulation space. We introduce the face-centered cubic (FCC) lattice, fD3Q13, for LBM simulations. Compared to the CC lattices, the fD3Q13 lattice creates a more isotropic sampling of the simulation domain and its single lattice speed (i.e., link length) simplifies the computations and data storage. Furthermore, the fD3Q13 lattice can be decomposed into two independent interleaved lattices, one of which can be discarded, which doubles the simulation speed. The resulting LBM simulation can be efficiently mapped to the GPU, further increasing the computational performance. We show the numerical advantages of the FCC lattice on channeled flow in 2D and the flow-past-a-sphere benchmark in 3D. In both cases, the comparison is against the corresponding CC lattices using the analytical solutions for the systems as well as velocity field visualizations. We also demonstrate the performance advantages of the fD3Q13 lattice for interactive simulation and rendering of hot smoke in an urban environment using thermal LBM.

Sonification and haptic feedback in addition to visual feedback enhances complex motor task learning.

Science.gov (United States)

Sigrist, Roland; Rauter, Georg; Marchal-Crespo, Laura; Riener, Robert; Wolf, Peter

2015-03-01

Concurrent augmented feedback has been shown to be less effective for learning simple motor tasks than for complex tasks. However, as mostly artificial tasks have been investigated, transfer of results to tasks in sports and rehabilitation remains unknown. Therefore, in this study, the effect of different concurrent feedback was evaluated in trunk-arm rowing. It was then investigated whether multimodal audiovisual and visuohaptic feedback are more effective for learning than visual feedback only. Naïve subjects (N = 24) trained in three groups on a highly realistic virtual reality-based rowing simulator. In the visual feedback group, the subject's oar was superimposed to the target oar, which continuously became more transparent when the deviation between the oars decreased. Moreover, a trace of the subject's trajectory emerged if deviations exceeded a threshold. The audiovisual feedback group trained with oar movement sonification in addition to visual feedback to facilitate learning of the velocity profile. In the visuohaptic group, the oar movement was inhibited by path deviation-dependent braking forces to enhance learning of spatial aspects. All groups significantly decreased the spatial error (tendency in visual group) and velocity error from baseline to the retention tests. Audiovisual feedback fostered learning of the velocity profile significantly more than visuohaptic feedback. The study revealed that well-designed concurrent feedback fosters complex task learning, especially if the advantages of different modalities are exploited. Further studies should analyze the impact of within-feedback design parameters and the transferability of the results to other tasks in sports and rehabilitation.

Learning efficient visual search for stimuli containing diagnostic spatial configurations and color-shape conjunctions.

Science.gov (United States)

Reavis, Eric A; Frank, Sebastian M; Tse, Peter U

2018-04-12

Visual search is often slow and difficult for complex stimuli such as feature conjunctions. Search efficiency, however, can improve with training. Search for stimuli that can be identified by the spatial configuration of two elements (e.g., the relative position of two colored shapes) improves dramatically within a few hundred trials of practice. Several recent imaging studies have identified neural correlates of this learning, but it remains unclear what stimulus properties participants learn to use to search efficiently. Influential models, such as reverse hierarchy theory, propose two major possibilities: learning to use information contained in low-level image statistics (e.g., single features at particular retinotopic locations) or in high-level characteristics (e.g., feature conjunctions) of the task-relevant stimuli. In a series of experiments, we tested these two hypotheses, which make different predictions about the effect of various stimulus manipulations after training. We find relatively small effects of manipulating low-level properties of the stimuli (e.g., changing their retinotopic location) and some conjunctive properties (e.g., color-position), whereas the effects of manipulating other conjunctive properties (e.g., color-shape) are larger. Overall, the findings suggest conjunction learning involving such stimuli might be an emergent phenomenon that reflects multiple different learning processes, each of which capitalizes on different types of information contained in the stimuli. We also show that both targets and distractors are learned, and that reversing learned target and distractor identities impairs performance. This suggests that participants do not merely learn to discriminate target and distractor stimuli, they also learn stimulus identity mappings that contribute to performance improvements.

Complexity Plots

KAUST Repository

Thiyagalingam, Jeyarajan

2013-06-01

In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

Complex network inference from P300 signals: Decoding brain state under visual stimulus for able-bodied and disabled subjects

Science.gov (United States)

Gao, Zhong-Ke; Cai, Qing; Dong, Na; Zhang, Shan-Shan; Bo, Yun; Zhang, Jie

2016-10-01

Distinguishing brain cognitive behavior underlying disabled and able-bodied subjects constitutes a challenging problem of significant importance. Complex network has established itself as a powerful tool for exploring functional brain networks, which sheds light on the inner workings of the human brain. Most existing works in constructing brain network focus on phase-synchronization measures between regional neural activities. In contrast, we propose a novel approach for inferring functional networks from P300 event-related potentials by integrating time and frequency domain information extracted from each channel signal, which we show to be efficient in subsequent pattern recognition. In particular, we construct brain network by regarding each channel signal as a node and determining the edges in terms of correlation of the extracted feature vectors. A six-choice P300 paradigm with six different images is used in testing our new approach, involving one able-bodied subject and three disabled subjects suffering from multiple sclerosis, cerebral palsy, traumatic brain and spinal-cord injury, respectively. We then exploit global efficiency, local efficiency and small-world indices from the derived brain networks to assess the network topological structure associated with different target images. The findings suggest that our method allows identifying brain cognitive behaviors related to visual stimulus between able-bodied and disabled subjects.

Complex signal-based optical coherence tomography angiography enables in vivo visualization of choriocapillaris in human choroid

Science.gov (United States)

Chu, Zhongdi; Chen, Chieh-Li; Zhang, Qinqin; Pepple, Kathryn; Durbin, Mary; Gregori, Giovanni; Wang, Ruikang K.

2017-12-01

The choriocapillaris (CC) plays an essential role in maintaining the normal functions of the human eye. There is increasing interest in the community to develop an imaging technique for visualizing the CC, yet this remains underexplored due to technical limitations. We propose an approach for the visualization of the CC in humans via a complex signal-based optical microangiography (OMAG) algorithm, based on commercially available spectral domain optical coherence tomography (SD-OCT). We show that the complex signal-based OMAG was superior to both the phase and amplitude signal-based approaches in detailing the vascular lobules previously seen with histological analysis. With this improved ability to visualize the lobular vascular networks, it is possible to identify the feeding arterioles and draining venules around the lobules, which is important in understanding the role of the CC in the pathogenesis of ocular diseases. With built-in FastTrac™ and montage scanning capabilities, we also demonstrate wide-field SD-OCT angiograms of the CC with a field of view at 9×11 mm2.

The geosystems of complex geographical atlases

Directory of Open Access Journals (Sweden)

Jovanović Jasmina

2012-01-01

Full Text Available Complex geographical atlases represent geosystems of different hierarchical rank, complexity and diversity, scale and connection. They represent a set of large number of different pieces of information about geospace. Also, they contain systematized, correlative and in the apparent form represented pieces of information about space. The degree of information revealed in the atlas is precisely explained by its content structure and the form of presentation. The quality of atlas depends on the method of visualization of data and the quality of geodata. Cartographic visualization represents cognitive process. The analysis converts geospatial data into knowledge. A complex geographical atlas represents information complex of spatial - temporal coordinated database on geosystems of different complexity and territorial scope. Each geographical atlas defines a concrete geosystem. Systemic organization (structural and contextual determines its complexity and concreteness. In complex atlases, the attributes of geosystems are modeled and pieces of information are given in systematized, graphically unique form. The atlas can be considered as a database. In composing a database, semantic analysis of data is important. The result of semantic modeling is expressed in structuring of data information, in emphasizing logic connections between phenomena and processes and in defining their classes according to the degree of similarity. Accordingly, the efficiency of research of needed pieces of information in the process of the database use is enabled. An atlas map has a special power to integrate sets of geodata and present information contents in user - friendly and understandable visual and tactile way using its visual ability. Composing an atlas by systemic cartography requires the pieces of information on concrete - defined geosystems of different hierarchical level, the application of scientific methods and making of adequate number of analytical, synthetic

Teaching Geosciences With Visualizations: Challenges for Spatial Thinking and Abilities

Science.gov (United States)

Montello, D. R.

2004-12-01

It is widely recognized that the geosciences are very spatial disciplines. Their subject matter includes phenomena on, under, and above the Earth surface whose spatial properties are critical to understanding them. Important spatial properties of geoscience structures and processes include location (both absolute and relative), size, shape, and pattern; temporal changes in spatial properties are also of interest. Information visualizations that depict spatiality are thus critically important to teaching in the geosciences, at all levels from K-12 to Ph.D. work; verbal and mathematical descriptions are quite insufficient by themselves. Such visualizations range from traditional maps and diagrams to digital animations and virtual environments. These visualizations are typically rich and complex because they are attempts to communicate rich and complex realities. Thus, understanding geoscience visualizations accurately and efficiently involves complex spatial thinking. Over a century of psychometric and experimental research reveals some of the cognitive components of spatial thinking, and provides insight into differences among individuals and groups of people in their abilities to think spatially. Some research has specifically examined these issues within the context of geoscience education, and recent research is expanding these investigations into the realm of new digital visualizations that offer the hope of using visualizations to teach complex geoscience concepts with unprecedented effectiveness. In this talk, I will briefly highlight some of the spatial cognitive challenges to understanding geoscience visualizations, including the pervasive and profound individual and group differences in spatial abilities. I will also consider some visualization design issues that arise because of the cognitive and ability challenges. I illustrate some of these research issues with examples from research being conducted by my colleagues and me, research informed by

An efficient Korringa-Kohn-Rostoker method for ''complex'' lattices

International Nuclear Information System (INIS)

Yussouff, M.; Zeller, R.

1980-10-01

We present a modification of the exact KKR-band structure method which uses (a) a new energy expansion for structure constants and (b) only the reciprocal lattice summation. It is quite efficient and particularly useful for 'complex' lattices. The band structure of hexagonal-close-packed Beryllium at symmetry points is presented as an example of this method. (author)

Interactive Visual Analysis within Dynamic Ocean Models

Science.gov (United States)

Butkiewicz, T.

2012-12-01

The many observation and simulation based ocean models available today can provide crucial insights for all fields of marine research and can serve as valuable references when planning data collection missions. However, the increasing size and complexity of these models makes leveraging their contents difficult for end users. Through a combination of data visualization techniques, interactive analysis tools, and new hardware technologies, the data within these models can be made more accessible to domain scientists. We present an interactive system that supports exploratory visual analysis within large-scale ocean flow models. The currents and eddies within the models are illustrated using effective, particle-based flow visualization techniques. Stereoscopic displays and rendering methods are employed to ensure that the user can correctly perceive the complex 3D structures of depth-dependent flow patterns. Interactive analysis tools are provided which allow the user to experiment through the introduction of their customizable virtual dye particles into the models to explore regions of interest. A multi-touch interface provides natural, efficient interaction, with custom multi-touch gestures simplifying the otherwise challenging tasks of navigating and positioning tools within a 3D environment. We demonstrate the potential applications of our visual analysis environment with two examples of real-world significance: Firstly, an example of using customized particles with physics-based behaviors to simulate pollutant release scenarios, including predicting the oil plume path for the 2010 Deepwater Horizon oil spill disaster. Secondly, an interactive tool for plotting and revising proposed autonomous underwater vehicle mission pathlines with respect to the surrounding flow patterns predicted by the model; as these survey vessels have extremely limited energy budgets, designing more efficient paths allows for greater survey areas.

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

Science.gov (United States)

Titov, Alexander; Gordov, Evgeny; Okladnikov, Igor

2016-04-01

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

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

KAUST Repository

Aboulhassan, A.

2017-07-04

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

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

KAUST Repository

Aboulhassan, A.; Sicat, R.; Baum, D.; Wodo, O.; Hadwiger, Markus

2017-01-01

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

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

Directory of Open Access Journals (Sweden)

Rainer Koppler

1997-01-01

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

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

Directory of Open Access Journals (Sweden)

Mecit Sari

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

Entropic Movement Complexity Reflects Subjective Creativity Rankings of Visualized Hand Motion Trajectories

Science.gov (United States)

Peng, Zhen; Braun, Daniel A.

2015-01-01

In a previous study we have shown that human motion trajectories can be characterized by translating continuous trajectories into symbol sequences with well-defined complexity measures. Here we test the hypothesis that the motion complexity individuals generate in their movements might be correlated to the degree of creativity assigned by a human observer to the visualized motion trajectories. We asked participants to generate 55 novel hand movement patterns in virtual reality, where each pattern had to be repeated 10 times in a row to ensure reproducibility. This allowed us to estimate a probability distribution over trajectories for each pattern. We assessed motion complexity not only by the previously proposed complexity measures on symbolic sequences, but we also propose two novel complexity measures that can be directly applied to the distributions over trajectories based on the frameworks of Gaussian Processes and Probabilistic Movement Primitives. In contrast to previous studies, these new methods allow computing complexities of individual motion patterns from very few sample trajectories. We compared the different complexity measures to how a group of independent jurors rank ordered the recorded motion trajectories according to their personal creativity judgment. We found three entropic complexity measures that correlate significantly with human creativity judgment and discuss differences between the measures. We also test whether these complexity measures correlate with individual creativity in divergent thinking tasks, but do not find any consistent correlation. Our results suggest that entropic complexity measures of hand motion may reveal domain-specific individual differences in kinesthetic creativity. PMID:26733896

Interactive volume visualization of general polyhedral grids

KAUST Repository

Muigg, Philipp

2011-12-01

This paper presents a novel framework for visualizing volumetric data specified on complex polyhedral grids, without the need to perform any kind of a priori tetrahedralization. These grids are composed of polyhedra that often are non-convex and have an arbitrary number of faces, where the faces can be non-planar with an arbitrary number of vertices. The importance of such grids in state-of-the-art simulation packages is increasing rapidly. We propose a very compact, face-based data structure for representing such meshes for visualization, called two-sided face sequence lists (TSFSL), as well as an algorithm for direct GPU-based ray-casting using this representation. The TSFSL data structure is able to represent the entire mesh topology in a 1D TSFSL data array of face records, which facilitates the use of efficient 1D texture accesses for visualization. In order to scale to large data sizes, we employ a mesh decomposition into bricks that can be handled independently, where each brick is then composed of its own TSFSL array. This bricking enables memory savings and performance improvements for large meshes. We illustrate the feasibility of our approach with real-world application results, by visualizing highly complex polyhedral data from commercial state-of-the-art simulation packages. © 2011 IEEE.

Tailored information for cancer patients on the Internet: effects of visual cues and language complexity on information recall and satisfaction.

NARCIS (Netherlands)

Weert, J.C.M. van; Noort, G. van; Bol, N.; Dijk, L. van; Tates, K.; Jansen, J.

2011-01-01

Objective: This study was designed to investigate the effects of visual cues and language complexity on satisfaction and information recall using a personalised website for lung cancer patients. In addition, age effects were investigated. Methods: An experiment using a 2 (complex vs. non-complex

Tailored information for cancer patients on the Internet: effects of visual cues and language complexity on information recall and satisfaction

NARCIS (Netherlands)

van Weert, J.C.M.; van Noort, G.; Bol, N.; van Dijk, L.; Tates, K.; Jansen, J.

2011-01-01

Objective This study was designed to investigate the effects of visual cues and language complexity on satisfaction and information recall using a personalised website for lung cancer patients. In addition, age effects were investigated. Methods An experiment using a 2 (complex vs. non-complex

In the working memory of the beholder: Art appreciation is enhanced when visual complexity is compatible with working memory.

Science.gov (United States)

Sherman, Aleksandra; Grabowecky, Marcia; Suzuki, Satoru

2015-08-01

What shapes art appreciation? Much research has focused on the importance of visual features themselves (e.g., symmetry, natural scene statistics) and of the viewer's experience and expertise with specific artworks. However, even after taking these factors into account, there are considerable individual differences in art preferences. Our new result suggests that art preference is also influenced by the compatibility between visual properties and the characteristics of the viewer's visual system. Specifically, we have demonstrated, using 120 artworks from diverse periods, cultures, genres, and styles, that art appreciation is increased when the level of visual complexity within an artwork is compatible with the viewer's visual working memory capacity. The result highlights the importance of the interaction between visual features and the beholder's general visual capacity in shaping art appreciation. (c) 2015 APA, all rights reserved).

Selective transfer of visual working memory training on Chinese character learning.

Science.gov (United States)

Opitz, Bertram; Schneiders, Julia A; Krick, Christoph M; Mecklinger, Axel

2014-01-01

Previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages. However, little is known about the impact of working memory processes on second language learning in a non-alphabetic language such as Mandarin Chinese. Due to the greater complexity of the Chinese writing system we expect that visual working memory rather than phonological working memory exerts a unique influence on learning Chinese characters. This issue was explored in the present experiment by comparing visual working memory training with an active (auditory working memory training) control condition and a passive, no training control condition. Training induced modulations in language-related brain networks were additionally examined using functional magnetic resonance imaging in a pretest-training-posttest design. As revealed by pre- to posttest comparisons and analyses of individual differences in working memory training gains, visual working memory training led to positive transfer effects on visual Chinese vocabulary learning compared to both control conditions. In addition, we found sustained activation after visual working memory training in the (predominantly visual) left infero-temporal cortex that was associated with behavioral transfer. In the control conditions, activation either increased (active control condition) or decreased (passive control condition) without reliable behavioral transfer effects. This suggests that visual working memory training leads to more efficient processing and more refined responses in brain regions involved in visual processing. Furthermore, visual working memory training boosted additional activation in the precuneus, presumably reflecting mental image generation of the learned characters. We, therefore, suggest that the conjoint activity of the mid-fusiform gyrus and the precuneus after visual working memory training reflects an interaction of working memory and

User evaluations of design complexity: the impact of visual perceptions for effective online health communication.

Science.gov (United States)

Lazard, Allison; Mackert, Michael

2014-10-01

This paper highlights the influential role of design complexity for users' first impressions of health websites. An experimental design was utilized to investigate whether a website's level of design complexity impacts user evaluations. An online questionnaire measured the hypothesized impact of design complexity on predictors of message effectiveness. Findings reveal that increased design complexity was positively associated with higher levels of perceived design esthetics, attitude toward the website, perceived message comprehensibility, perceived ease of use, perceived usefulness, perceived message quality, perceived informativeness, and perceived visual informativeness. This research gives further evidence that design complexity should be considered an influential variable for health communicators to effectively reach their audiences, as it embodies the critical first step for message evaluation via electronic platforms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Interfaces Visualize Data for Airline Safety, Efficiency

Science.gov (United States)

2014-01-01

As the A-Train Constellation orbits Earth to gather data, NASA scientists and partners visualize, analyze, and communicate the information. To this end, Langley Research Center awarded SBIR funding to Fairfax, Virginia-based WxAnalyst Ltd. to refine the company's existing user interface for Google Earth to visualize data. Hawaiian Airlines is now using the technology to help manage its flights.

3D modeling and visualization software for complex geometries

International Nuclear Information System (INIS)

Guse, Guenter; Klotzbuecher, Michael; Mohr, Friedrich

2011-01-01

The reactor safety depends on reliable nondestructive testing of reactor components. For 100% detection probability of flaws and the determination of their size using ultrasonic methods the ultrasonic waves have to hit the flaws within a specific incidence and squint angle. For complex test geometries like testing of nozzle welds from the outside of the component these angular ranges can only be determined using elaborate mathematical calculations. The authors developed a 3D modeling and visualization software tool that allows to integrate and present ultrasonic measuring data into the 3D geometry. The software package was verified using 1:1 test samples (example: testing of the nozzle edge of the feedwater nozzle of a steam generator from the outside; testing of the reactor pressure vessel nozzle edge from the inside).

AstroBlend: An astrophysical visualization package for Blender

Science.gov (United States)

Naiman, J. P.

2016-04-01

The rapid growth in scale and complexity of both computational and observational astrophysics over the past decade necessitates efficient and intuitive methods for examining and visualizing large datasets. Here, I present AstroBlend, an open-source Python library for use within the three dimensional modeling software, Blender. While Blender has been a popular open-source software among animators and visual effects artists, in recent years it has also become a tool for visualizing astrophysical datasets. AstroBlend combines the three dimensional capabilities of Blender with the analysis tools of the widely used astrophysical toolset, yt, to afford both computational and observational astrophysicists the ability to simultaneously analyze their data and create informative and appealing visualizations. The introduction of this package includes a description of features, work flow, and various example visualizations. A website - www.astroblend.com - has been developed which includes tutorials, and a gallery of example images and movies, along with links to downloadable data, three dimensional artistic models, and various other resources.

Linking Automated Data Analysis and Visualization with Applications in Developmental Biology and High-Energy Physics

Energy Technology Data Exchange (ETDEWEB)

Ruebel, Oliver [Technical Univ. of Darmstadt (Germany)

2009-11-20

Knowledge discovery from large and complex collections of today's scientific datasets is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the increasing number of data dimensions and data objects is presenting tremendous challenges for data analysis and effective data exploration methods and tools. Researchers are overwhelmed with data and standard tools are often insufficient to enable effective data analysis and knowledge discovery. The main objective of this thesis is to provide important new capabilities to accelerate scientific knowledge discovery form large, complex, and multivariate scientific data. The research covered in this thesis addresses these scientific challenges using a combination of scientific visualization, information visualization, automated data analysis, and other enabling technologies, such as efficient data management. The effectiveness of the proposed analysis methods is demonstrated via applications in two distinct scientific research fields, namely developmental biology and high-energy physics.Advances in microscopy, image analysis, and embryo registration enable for the first time measurement of gene expression at cellular resolution for entire organisms. Analysis of high-dimensional spatial gene expression datasets is a challenging task. By integrating data clustering and visualization, analysis of complex, time-varying, spatial gene expression patterns and their formation becomes possible. The analysis framework MATLAB and the visualization have been integrated, making advanced analysis tools accessible to biologist and enabling bioinformatic researchers to directly integrate their analysis with the visualization. Laser wakefield particle accelerators (LWFAs) promise to be a new compact source of high-energy particles and radiation, with wide applications ranging from medicine to physics. To gain insight into the complex physical processes of particle

Linking Automated Data Analysis and Visualization with Applications in Developmental Biology and High-Energy Physics

International Nuclear Information System (INIS)

Ruebel, Oliver

2009-01-01

Knowledge discovery from large and complex collections of today's scientific datasets is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the increasing number of data dimensions and data objects is presenting tremendous challenges for data analysis and effective data exploration methods and tools. Researchers are overwhelmed with data and standard tools are often insufficient to enable effective data analysis and knowledge discovery. The main objective of this thesis is to provide important new capabilities to accelerate scientific knowledge discovery form large, complex, and multivariate scientific data. The research covered in this thesis addresses these scientific challenges using a combination of scientific visualization, information visualization, automated data analysis, and other enabling technologies, such as efficient data management. The effectiveness of the proposed analysis methods is demonstrated via applications in two distinct scientific research fields, namely developmental biology and high-energy physics.Advances in microscopy, image analysis, and embryo registration enable for the first time measurement of gene expression at cellular resolution for entire organisms. Analysis of high-dimensional spatial gene expression datasets is a challenging task. By integrating data clustering and visualization, analysis of complex, time-varying, spatial gene expression patterns and their formation becomes possible. The analysis framework MATLAB and the visualization have been integrated, making advanced analysis tools accessible to biologist and enabling bioinformatic researchers to directly integrate their analysis with the visualization. Laser wakefield particle accelerators (LWFAs) promise to be a new compact source of high-energy particles and radiation, with wide applications ranging from medicine to physics. To gain insight into the complex physical processes of particle

Estimation of Economic Efficiency of Regional Touristic Complex

Directory of Open Access Journals (Sweden)

Kurchenkov Vladimir Viktorovich

2015-09-01

Full Text Available The article describes the features of the development of the regional touristic complex in modern conditions and determines the direction of realizing the potential of the regional market of tourist services. The authors reveal the multiplicative interrelation for analyzing the interaction of the primary and secondary sectors of the regional market of tourist services. The key indicators of efficiency are outlined, the extent of their relevance for assessing the potential of international tourism in the region is revealed. The authors calculate the relative indicators reflecting the dynamics of incomes from inbound, outbound and domestic tourism in relation to the total income from tourism activities in the region during the reporting period, usually for one calendar year. On the basis of these parameters, the classification of the regions of the Southern Federal District in terms of tourist attraction is carried out. The authors determine the reasons of the low tourist attractiveness of the Volgograd region in comparison with other regions of the Southern Federal District. It is substantiated that the potential of expanding tourism activity is not fully realized today in the Volgograd region. The technique of analysis and evaluation of the effectiveness of regional touristic complex on the basis of cluster approach is suggested. For analyzing the effectiveness of regional tourism cluster the authors propose to use indicators that reflect the overall performance of the regional tourism cluster, characterizing the impact of cluster development of the area, or the regional market, as well as evaluating the performance of each of the companies cooperating in the framework of the cluster. The article contains recommendations to the regional authorities on improving the efficiency of regional touristic complex in the short- and long-term prospects.

Rapid visual and spectrophotometric nitrite detection by cyclometalated ruthenium complex.

Science.gov (United States)

Lo, Hoi-Shing; Lo, Ka-Wai; Yeung, Chi-Fung; Wong, Chun-Yuen

2017-10-16

Quantitative determination of nitrite ion (NO 2 - ) is of great importance in environmental and clinical investigations. A rapid visual and spectrophotometric assay for NO 2 - detection was developed based on a newly designed ruthenium complex, [Ru(npy)([9]aneS3)(CO)](ClO 4 ) (denoted as RuNPY; npy = 2-(1-naphthyl)pyridine, [9]aneS3 = 1,4,7-trithiacyclononane). This complex traps NO + produced in acidified NO 2 - solution, and yields observable color change within 1 min at room temperature. The assay features excellent dynamic range (1-840 μmol L -1 ) and high selectivity, and its limit of detection (0.39 μmol L -1 ) is also well below the guideline values for drinking water recommended by WHO and U.S. EPA. Practical use of this assay in tap water and human urine was successfully demonstrated. Overall, the rapidity and selectivity of this assay overcome the problems suffered by the commonly used modified Griess assays for nitrite determination. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling human comprehension of data visualizations

Energy Technology Data Exchange (ETDEWEB)

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

2017-09-01

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

Development and validation of an interactive efficient dose rates distribution calculation program ARShield for visualization of radiation field in nuclear power plants

International Nuclear Information System (INIS)

He, Shuxiang; Zhang, Han; Wang, Mengqi; Zang, Qiyong; Zhang, Jingyu; Chen, Yixue

2017-01-01

Point kernel integration (PKI) method is widely used in the visualization of radiation field in engineering applications because of the features of quickly dealing with large-scale complicated geometry space problems. But the traditional PKI programs have a lot of restrictions, such as complicated modeling, complicated source setting, 3D fine mesh results statistics and large-scale computing efficiency. To break the traditional restrictions for visualization of radiation field, ARShield was developed successfully. The results show that ARShield can deal with complicated plant radiation shielding problems for visualization of radiation field. Compared with SuperMC and QAD, it can be seen that the program is reliable and efficient. Also, ARShield can meet the demands of calculation speediness and interactive operations of modeling and displaying 3D geometries on a graphical user interface, avoiding error modeling in calculation and visualization. (authors)

Information, complexity and efficiency: The automobile model

Energy Technology Data Exchange (ETDEWEB)

Allenby, B. [Lucent Technologies (United States)]|[Lawrence Livermore National Lab., CA (United States)

1996-08-08

The new, rapidly evolving field of industrial ecology - the objective, multidisciplinary study of industrial and economic systems and their linkages with fundamental natural systems - provides strong ground for believing that a more environmentally and economically efficient economy will be more information intensive and complex. Information and intellectual capital will be substituted for the more traditional inputs of materials and energy in producing a desirable, yet sustainable, quality of life. While at this point this remains a strong hypothesis, the evolution of the automobile industry can be used to illustrate how such substitution may, in fact, already be occurring in an environmentally and economically critical sector.

Complex cells decrease errors for the Müller-Lyer illusion in a model of the visual ventral stream.

Science.gov (United States)

Zeman, Astrid; Obst, Oliver; Brooks, Kevin R

2014-01-01

To improve robustness in object recognition, many artificial visual systems imitate the way in which the human visual cortex encodes object information as a hierarchical set of features. These systems are usually evaluated in terms of their ability to accurately categorize well-defined, unambiguous objects and scenes. In the real world, however, not all objects and scenes are presented clearly, with well-defined labels and interpretations. Visual illusions demonstrate a disparity between perception and objective reality, allowing psychophysicists to methodically manipulate stimuli and study our interpretation of the environment. One prominent effect, the Müller-Lyer illusion, is demonstrated when the perceived length of a line is contracted (or expanded) by the addition of arrowheads (or arrow-tails) to its ends. HMAX, a benchmark object recognition system, consistently produces a bias when classifying Müller-Lyer images. HMAX is a hierarchical, artificial neural network that imitates the "simple" and "complex" cell layers found in the visual ventral stream. In this study, we perform two experiments to explore the Müller-Lyer illusion in HMAX, asking: (1) How do simple vs. complex cell operations within HMAX affect illusory bias and precision? (2) How does varying the position of the figures in the input image affect classification using HMAX? In our first experiment, we assessed classification after traversing each layer of HMAX and found that in general, kernel operations performed by simple cells increase bias and uncertainty while max-pooling operations executed by complex cells decrease bias and uncertainty. In our second experiment, we increased variation in the positions of figures in the input images that reduced bias and uncertainty in HMAX. Our findings suggest that the Müller-Lyer illusion is exacerbated by the vulnerability of simple cell operations to positional fluctuations, but ameliorated by the robustness of complex cell responses to such

Complexity control algorithm based on adaptive mode selection for interframe coding in high efficiency video coding

Science.gov (United States)

Chen, Gang; Yang, Bing; Zhang, Xiaoyun; Gao, Zhiyong

2017-07-01

The latest high efficiency video coding (HEVC) standard significantly increases the encoding complexity for improving its coding efficiency. Due to the limited computational capability of handheld devices, complexity constrained video coding has drawn great attention in recent years. A complexity control algorithm based on adaptive mode selection is proposed for interframe coding in HEVC. Considering the direct proportionality between encoding time and computational complexity, the computational complexity is measured in terms of encoding time. First, complexity is mapped to a target in terms of prediction modes. Then, an adaptive mode selection algorithm is proposed for the mode decision process. Specifically, the optimal mode combination scheme that is chosen through offline statistics is developed at low complexity. If the complexity budget has not been used up, an adaptive mode sorting method is employed to further improve coding efficiency. The experimental results show that the proposed algorithm achieves a very large complexity control range (as low as 10%) for the HEVC encoder while maintaining good rate-distortion performance. For the lowdelayP condition, compared with the direct resource allocation method and the state-of-the-art method, an average gain of 0.63 and 0.17 dB in BDPSNR is observed for 18 sequences when the target complexity is around 40%.

Visual Constructive and Visual-Motor Skills in Deaf Native Signers

Science.gov (United States)

Hauser, Peter C.; Cohen, Julie; Dye, Matthew W. G.; Bavelier, Daphne

2007-01-01

Visual constructive and visual-motor skills in the deaf population were investigated by comparing performance of deaf native signers (n = 20) to that of hearing nonsigners (n = 20) on the Beery-Buktenica Developmental Test of Visual-Motor Integration, Rey-Osterrieth Complex Figure Test, Wechsler Memory Scale Visual Reproduction subtest, and…

LOD-based clustering techniques for efficient large-scale terrain storage and visualization

Science.gov (United States)

Bao, Xiaohong; Pajarola, Renato

2003-05-01

Large multi-resolution terrain data sets are usually stored out-of-core. To visualize terrain data at interactive frame rates, the data needs to be organized on disk, loaded into main memory part by part, then rendered efficiently. Many main-memory algorithms have been proposed for efficient vertex selection and mesh construction. Organization of terrain data on disk is quite difficult because the error, the triangulation dependency and the spatial location of each vertex all need to be considered. Previous terrain clustering algorithms did not consider the per-vertex approximation error of individual terrain data sets. Therefore, the vertex sequences on disk are exactly the same for any terrain. In this paper, we propose a novel clustering algorithm which introduces the level-of-detail (LOD) information to terrain data organization to map multi-resolution terrain data to external memory. In our approach the LOD parameters of the terrain elevation points are reflected during clustering. The experiments show that dynamic loading and paging of terrain data at varying LOD is very efficient and minimizes page faults. Additionally, the preprocessing of this algorithm is very fast and works from out-of-core.

Auditory Scene Analysis and sonified visual images. Does consonance negatively impact on object formation when using complex sonified stimuli?

Directory of Open Access Journals (Sweden)

David J Brown

2015-10-01

Full Text Available A critical task for the brain is the sensory representation and identification of perceptual objects in the world. When the visual sense is impaired, hearing and touch must take primary roles and in recent times compensatory techniques have been developed that employ the tactile or auditory system as a substitute for the visual system. Visual-to-auditory sonifications provide a complex, feature-based auditory representation that must be decoded and integrated into an object-based representation by the listener. However, we don’t yet know what role the auditory system plays in the object integration stage and whether the principles of auditory scene analysis apply. Here we used coarse sonified images in a two-tone discrimination task to test whether auditory feature-based representations of visual objects would be confounded when their features conflicted with the principles of auditory consonance. We found that listeners (N = 36 performed worse in an object recognition task when the auditory feature-based representation was harmonically consonant. We also found that this conflict was not negated with the provision of congruent audio-visual information. The findings suggest that early auditory processes of harmonic grouping dominate the object formation process and that the complexity of the signal, and additional sensory information have limited effect on this.

Polarization holograms allow highly efficient generation of complex light beams.

Science.gov (United States)

Ruiz, U; Pagliusi, P; Provenzano, C; Volke-Sepúlveda, K; Cipparrone, Gabriella

2013-03-25

We report a viable method to generate complex beams, such as the non-diffracting Bessel and Weber beams, which relies on the encoding of amplitude information, in addition to phase and polarization, using polarization holography. The holograms are recorded in polarization sensitive films by the interference of a reference plane wave with a tailored complex beam, having orthogonal circular polarizations. The high efficiency, the intrinsic achromaticity and the simplicity of use of the polarization holograms make them competitive with respect to existing methods and attractive for several applications. Theoretical analysis, based on the Jones formalism, and experimental results are shown.

Attention and visual memory in visualization and computer graphics.

Science.gov (United States)

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.

Visual Short-Term Memory Complexity

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik

Several recent studies have explored the nature and limits of visual short-term memory (VSTM) (e.g. Luck & Vogel, 1997). A general VSTM capacity limit of about 3 to 4 letters has been found, thus confirming results from earlier studies (e.g. Cattell, 1885; Sperling, 1960). However, Alvarez...

Proximity probing assays for simultaneous visualization of protein complexes in situ

DEFF Research Database (Denmark)

Moreira, José; Thorsen, Stine Buch; Brünner, Nils

2013-01-01

EVALUATION OF: Leuchowius KJ, Clausson CM, Grannas K et al. Parallel visualization of multiple protein complexes in individual cells in tumor tissue. Mol. Cell Proteomics doi:10.1074/mcp.O112.023374 (2013) (Epub ahead of print). Techniques for in situ detection and quantification of proteins...... in fixed tissue remain an important element of both basic biological analyses and clinical biomarker research. The practical importance of such techniques can be exemplified by the everyday clinical use of immunohistochemical detection of the estrogen receptor and HER2 in tissues from breast cancer...

Landscape Aesthetics and the Scenic Drivers of Amenity Migration in the New West: Naturalness, Visual Scale, and Complexity

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Jelena Vukomanovic

2014-04-01

Full Text Available Values associated with scenic beauty are common “pull factors” for amenity migrants, however the specific landscape features that attract amenity migration are poorly understood. In this study we focused on three visual quality metrics of the intermountain West (USA, with the objective of exploring the relationship between the location of exurban homes and aesthetic landscape preference, as exemplified through greenness, viewshed size, and terrain ruggedness. Using viewshed analysis, we compared the viewsheds of actual exurban houses to the viewsheds of randomly-distributed simulated (validation houses. We found that the actual exurban households can see significantly more vegetation and a more rugged (complex terrain than simulated houses. Actual exurban homes see a more rugged terrain, but do not necessarily see the highest peaks, suggesting that visual complexity throughout the viewshed may be more important. The viewsheds visible from the actual exurban houses were significantly larger than those visible from the simulated houses, indicating that visual scale is important to the general aesthetic experiences of exurbanites. The differences in visual quality metric values between actual exurban and simulated viewsheds call into question the use of county-level scales of analysis for the study of landscape preferences, which may miss key landscape aesthetic drivers of preference.

On the complex analysis of the reliability, safety, and economic efficiency of atomic electric power stations

International Nuclear Information System (INIS)

Emel'yanov, I.Ya.; Klemin, A.I.; Polyakov, E.F.

1977-01-01

The problem is posed of effectively increasing the engineering performance of nuclear electric power stations (APS). The principal components of the engineering performance of modern large APS are considered: economic efficiency, radiation safety, reliability, and their interrelationship. A nomenclature is proposed for the quantitative indices which most completely characterize the enumerated properties and are convenient for the analysis of the engineering performance. The urgent problem of developing a methodology for the complex analysis and optimization of the principal performance components is considered; this methodology is designed to increase the efficiency of the work on high-performance competitive APS. The principle of complex optimization of the reliability, safety, and economic-efficiency indices is formulated; specific recommendations are made for the practical realization of this principle. The structure of the complex quantiative analysis of the enumerated performance components is given. The urgency and promise of the complex approach to solving the problem of APS optimization is demonstrated, i.e., the solution of the problem of creating optimally reliable, fairly safe, and maximally economically efficient stations

Game-Theoretic Rate-Distortion-Complexity Optimization of High Efficiency Video Coding

DEFF Research Database (Denmark)

Ukhanova, Ann; Milani, Simone; Forchhammer, Søren

2013-01-01

profiles in order to tailor the computational load to the different hardware and power-supply resources of devices. In this work, we focus on optimizing the quantization parameter and partition depth in HEVC via a game-theoretic approach. The proposed rate control strategy alone provides 0.2 dB improvement......This paper presents an algorithm for rate-distortioncomplexity optimization for the emerging High Efficiency Video Coding (HEVC) standard, whose high computational requirements urge the need for low-complexity optimization algorithms. Optimization approaches need to specify different complexity...

Efficiency Control in Iridium Complex-Based Phosphorescent Light-Emitting Diodes

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Boucar Diouf

2012-01-01

Full Text Available Key factors to control the efficiency in iridium doped red and green phosphorescent light emitting diodes (PhOLEDs are discussed in this review: exciton confinement, charge trapping, dopant concentration and dopant molecular structure. They are not independent from each other but we attempt to present each of them in a situation where its specific effects are predominant. A good efficiency in PhOLEDs requires the triplet energy of host molecules to be sufficiently high to confine the triplet excitons within the emitting layer (EML. Furthermore, triplet excitons must be retained within the EML and should not drift into the nonradiative levels of the electron or hole transport layer (resp., ETL or HTL; this is achieved by carefully choosing the EML’s adjacent layers. We prove how reducing charge trapping results in higher efficiency in PhOLEDs. We show that there is an ideal concentration for a maximum efficiency of PhOLEDs. Finally, we present the effects of molecular structure on the efficiency of PhOLEDs using red iridium complex dopant with different modifications on the ligand to tune its highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO energies.

SPECIFIC FEATURES OF HIGHER EFFICIENCY IN FUNCTIONING OF ROAD-TRANSPORT COMPLEX IN THE REPUBLIC OF BELARUS

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M. G. Solodkaya

2015-01-01

Full Text Available The road-transport complex objectively reflects the essence of efficient transportation process which is carried out by transport facilities along the highways. The complex  emphasizes an equivalent contribution of transport facilities and highways in a unified transportation process. Efficiency of the state economy rigidly depends on availability of the developed and well-functioning network of highways. Countries with the developed economy which have generally finished creation of national highway networks continue to invest money in public road systems that stimulates development of industrial sectors, agriculture and trade, etc. Their progress and efficient functioning is possible only with the balanced, overall development of the road-transport complex of the country. Functioning of the road-transport complex is inextricable connected with the operation of automotive transport and road infrastructure. Interaction of these two components of the unified economic system is determined by technical characteristics of the automotive transport and transport and operational indices of  the highways. Development of methods for optimum organization of management for functioning of the road complex is considered as an important problem of the national economy while forming market economy mechanisms. Further growth of capital expenditures including  investments will be needed in order to ensure such road conditions that meet the requirements of modern and perspective road traffic. Management of the highway network conditions presupposes a selection of such set of regulatory impacts on road conditions which will allow to minimize expenses in the road-transport complex. Elaboration and realization of the most efficient repair measures serve as such regulatory impact. The purpose is achieved while solving the problem pertaining to minimization of expenses on  transportations in the road-transport complex in the process of the realization of the most

Final anatomic and visual outcomes appear independent of duration of silicone oil intraocular tamponade in complex retinal detachment surgery.

Science.gov (United States)

Rhatigan, Maedbh; McElnea, Elizabeth; Murtagh, Patrick; Stephenson, Kirk; Harris, Elaine; Connell, Paul; Keegan, David

2018-01-01

To report anatomic and visual outcomes following silicone oil removal in a cohort of patients with complex retinal detachment, to determine association between duration of tamponade and outcomes and to compare patients with oil removed and those with oil in situ in terms of demographic, surgical and visual factors. We reported a four years retrospective case series of 143 patients with complex retinal detachments who underwent intraocular silicone oil tamponade. Analysis between anatomic and visual outcomes, baseline demographics, duration of tamponade and number of surgical procedures were carried out using Fisher's exact test and unpaired two-tailed t -test. One hundred and six patients (76.2%) had undergone silicone oil removal at the time of review with 96 patients (90.6%) showing retinal reattachment following oil removal. Duration of tamponade was not associated with final reattachment rate or with a deterioration in best corrected visual acuity (BCVA). Patients with oil removed had a significantly better baseline and final BCVA compared to those under oil tamponade ( P =0.0001, <0.0001 respectively). Anatomic and visual outcomes in this cohort are in keeping with those reported in the literature. Favorable outcomes were seen with oil removal but duration of oil tamponade does not affect final attachment rate with modern surgical techniques and should be managed on a case by case basis.

Extensive video-game experience alters cortical networks for complex visuomotor transformations.

Science.gov (United States)

Granek, Joshua A; Gorbet, Diana J; Sergio, Lauren E

2010-10-01

Using event-related functional magnetic resonance imaging (fMRI), we examined the effect of video-game experience on the neural control of increasingly complex visuomotor tasks. Previously, skilled individuals have demonstrated the use of a more efficient movement control brain network, including the prefrontal, premotor, primary sensorimotor and parietal cortices. Our results extend and generalize this finding by documenting additional prefrontal cortex activity in experienced video gamers planning for complex eye-hand coordination tasks that are distinct from actual video-game play. These changes in activation between non-gamers and extensive gamers are putatively related to the increased online control and spatial attention required for complex visually guided reaching. These data suggest that the basic cortical network for processing complex visually guided reaching is altered by extensive video-game play. Crown Copyright © 2009. Published by Elsevier Srl. All rights reserved.

The effects of size, clutter, and complexity on vanishing-point distances in visual imagery.

Science.gov (United States)

Hubbard, T L; Baird, J C

1993-01-01

The portrayal of vanishing-point distances in visual imagery was examined in six experiments. In all experiments, subjects formed visual images of squares, and the squares were to be oriented orthogonally to subjects' line of sight. The squares differed in their level of surface complexity, and were either undivided, divided into 4 equally sized smaller squares, or divided into 16 equally sized smaller squares. Squares also differed in stated referent size, and ranged from 3 in. to 128 ft along each side. After subjects had formed an image of a specified square, they transformed their image so that the square was portrayed to move away from them. Eventually, the imaged square was portrayed to be so far away that if it were any further away, it could not be identified. Subjects estimated the distance to the square that was portrayed in their image at that time, the vanishing-point distance, and the relationship between stated referent size and imaged vanishing-point distance was best described by a power function with an exponent less than 1. In general, there were trends for exponents (slopes on log axes) to increase slightly and for multiplicative constants (y intercepts on log axes) to decrease as surface complexity increased. No differences in exponents or in multiplicative constants were found when the vanishing-point was approached from either subthreshold or suprathreshold directions. When clutter in the form of additional imaged objects located to either side of the primary imaged object was added to the image, the exponent of the vanishing-point function increased slightly and the multiplicative constant decreased. The success of a power function (and the failure of the size-distance invariance hypothesis) in describing the vanishing-point distance function calls into question the notions (a) that a constant grain size exists in the imaginal visual field at a given location and (b) that grain size specifies a lower limit in the storage of information in

Effects of visual and verbal interference tasks on olfactory memory: the role of task complexity.

Science.gov (United States)

Annett, J M; Leslie, J C

1996-08-01

Recent studies have demonstrated that visual and verbal suppression tasks interfere with olfactory memory in a manner which is partially consistent with a dual coding interpretation. However, it has been suggested that total task complexity rather than modality specificity of the suppression tasks might account for the observed pattern of results. This study addressed the issue of whether or not the level of difficulty and complexity of suppression tasks could explain the apparent modality effects noted in earlier experiments. A total of 608 participants were each allocated to one of 19 experimental conditions involving interference tasks which varied suppression type (visual or verbal), nature of complexity (single, double or mixed) and level of difficulty (easy, optimal or difficult) and presented with 13 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Both recognition and recall performance showed an overall effect for suppression nature, suppression level and time of testing with no effect for suppression type. The results lend only limited support to Paivio's (1986) dual coding theory, but have a number of characteristics which suggest that an adequate account of olfactory memory may be broadly similar to current theories of face and object recognition. All of these phenomena might be dealt with by an appropriately modified version of dual coding theory.

Colour and luminance contrasts predict the human detection of natural stimuli in complex visual environments.

Science.gov (United States)

White, Thomas E; Rojas, Bibiana; Mappes, Johanna; Rautiala, Petri; Kemp, Darrell J

2017-09-01

Much of what we know about human colour perception has come from psychophysical studies conducted in tightly-controlled laboratory settings. An enduring challenge, however, lies in extrapolating this knowledge to the noisy conditions that characterize our actual visual experience. Here we combine statistical models of visual perception with empirical data to explore how chromatic (hue/saturation) and achromatic (luminant) information underpins the detection and classification of stimuli in a complex forest environment. The data best support a simple linear model of stimulus detection as an additive function of both luminance and saturation contrast. The strength of each predictor is modest yet consistent across gross variation in viewing conditions, which accords with expectation based upon general primate psychophysics. Our findings implicate simple visual cues in the guidance of perception amidst natural noise, and highlight the potential for informing human vision via a fusion between psychophysical modelling and real-world behaviour. © 2017 The Author(s).

A synthetic visual plane algorithm for visibility computation in consideration of accuracy and efficiency

Science.gov (United States)

Yu, Jieqing; Wu, Lixin; Hu, Qingsong; Yan, Zhigang; Zhang, Shaoliang

2017-12-01

Visibility computation is of great interest to location optimization, environmental planning, ecology, and tourism. Many algorithms have been developed for visibility computation. In this paper, we propose a novel method of visibility computation, called synthetic visual plane (SVP), to achieve better performance with respect to efficiency, accuracy, or both. The method uses a global horizon, which is a synthesis of line-of-sight information of all nearer points, to determine the visibility of a point, which makes it an accurate visibility method. We used discretization of horizon to gain a good performance in efficiency. After discretization, the accuracy and efficiency of SVP depends on the scale of discretization (i.e., zone width). The method is more accurate at smaller zone widths, but this requires a longer operating time. Users must strike a balance between accuracy and efficiency at their discretion. According to our experiments, SVP is less accurate but more efficient than R2 if the zone width is set to one grid. However, SVP becomes more accurate than R2 when the zone width is set to 1/24 grid, while it continues to perform as fast or faster than R2. Although SVP performs worse than reference plane and depth map with respect to efficiency, it is superior in accuracy to these other two algorithms.

Visualizing Matrix Multiplication

Science.gov (United States)

Daugulis, Peteris; Sondore, Anita

2018-01-01

Efficient visualizations of computational algorithms are important tools for students, educators, and researchers. In this article, we point out an innovative visualization technique for matrix multiplication. This method differs from the standard, formal approach by using block matrices to make computations more visual. We find this method a…

New Technologies for Acquisition and 3-D Visualization of Geophysical and Other Data Types Combined for Enhanced Understandings and Efficiencies of Oil and Gas Operations, Deepwater Gulf of Mexico

Science.gov (United States)

Thomson, J. A.; Gee, L. J.; George, T.

2002-12-01

This presentation shows results of a visualization method used to display and analyze multiple data types in a geospatially referenced three-dimensional (3-D) space. The integrated data types include sonar and seismic geophysical data, pipeline and geotechnical engineering data, and 3-D facilities models. Visualization of these data collectively in proper 3-D orientation yields insights and synergistic understandings not previously obtainable. Key technological components of the method are: 1) high-resolution geophysical data obtained using a newly developed autonomous underwater vehicle (AUV), 2) 3-D visualization software that delivers correctly positioned display of multiple data types and full 3-D flight navigation within the data space and 3) a highly immersive visualization environment (HIVE) where multidisciplinary teams can work collaboratively to develop enhanced understandings of geospatially complex data relationships. The initial study focused on an active deepwater development area in the Green Canyon protraction area, Gulf of Mexico. Here several planned production facilities required detailed, integrated data analysis for design and installation purposes. To meet the challenges of tight budgets and short timelines, an innovative new method was developed based on the combination of newly developed technologies. Key benefits of the method include enhanced understanding of geologically complex seabed topography and marine soils yielding safer and more efficient pipeline and facilities siting. Environmental benefits include rapid and precise identification of potential locations of protected deepwater biological communities for avoidance and protection during exploration and production operations. In addition, the method allows data presentation and transfer of learnings to an audience outside the scientific and engineering team. This includes regulatory personnel, marine archaeologists, industry partners and others.

HI-VISUAL: A language supporting visual interaction in programming

International Nuclear Information System (INIS)

Monden, N.; Yoshino, Y.; Hirakawa, M.; Tanaka, M.; Ichikawa, T.

1984-01-01

This paper presents a language named HI-VISUAL which supports visual interaction in programming. Following a brief description of the language concept, the icon semantics and language primitives characterizing HI-VISUAL are extensively discussed. HI-VISUAL also shows a system extensively discussed. HI-VISUAL also shows a system extendability providing the possibility of organizing a high level application system as an integration of several existing subsystems, and will serve to developing systems in various fields of applications supporting simple and efficient interactions between programmer and computer. In this paper, the authors have presented a language named HI-VISUAL. Following a brief description of the language concept, the icon semantics and language primitives characterizing HI-VISUAL were extensively discussed

Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

Science.gov (United States)

Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

2014-07-01

Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors. Copyright © 2013 Wiley Periodicals, Inc.

Complex cells decrease errors for the Müller-Lyer illusion in a model of the visual ventral stream

Directory of Open Access Journals (Sweden)

Astrid eZeman

2014-09-01

Full Text Available To improve robustness in object recognition, many artificial visual systems imitate the way in which the human visual cortex encodes object information as a hierarchical set of features. These systems are usually evaluated in terms of their ability to accurately categorize well-defined, unambiguous objects and scenes. In the real world, however, not all objects and scenes are presented clearly, with well-defined labels and interpretations. Visual illusions demonstrate a disparity between perception and objective reality, allowing psychophysicists to methodically manipulate stimuli and study our interpretation of the environment. One prominent effect, the Müller-Lyer illusion, is demonstrated when the perceived length of a line is contracted (or expanded by the addition of arrowheads (or arrow-tails to its ends. HMAX, a benchmark object recognition system, consistently produces a bias when classifying Müller-Lyer images. HMAX is a hierarchical, artificial neural network that imitates the ‘simple’ and ‘complex’ cell layers found in the visual ventral stream. In this study, we perform two experiments to explore the Müller-Lyer illusion in HMAX, asking: 1 How do simple versus complex cell operations within HMAX affect illusory bias and precision? 2 How does varying the position of the figures in the input image affect classification using HMAX? In our first experiment, we assessed classification after traversing each layer of HMAX and found that in general, kernel operations performed by simple cells increase bias and uncertainty while max-pooling operations executed by complex cells decrease bias and uncertainty. In our second experiment, we increased variation in the positions of figures in the input that reduced bias and uncertainty in HMAX. Our findings suggest that the Müller-Lyer illusion is exacerbated by the vulnerability of simple cell operations to positional fluctuations, but ameliorated by the robustness of complex cell

Visual search asymmetries within color-coded and intensity-coded displays.

Science.gov (United States)

Yamani, Yusuke; McCarley, Jason S

2010-06-01

Color and intensity coding provide perceptual cues to segregate categories of objects within a visual display, allowing operators to search more efficiently for needed information. Even within a perceptually distinct subset of display elements, however, it may often be useful to prioritize items representing urgent or task-critical information. The design of symbology to produce search asymmetries (Treisman & Souther, 1985) offers a potential technique for doing this, but it is not obvious from existing models of search that an asymmetry observed in the absence of extraneous visual stimuli will persist within a complex color- or intensity-coded display. To address this issue, in the current study we measured the strength of a visual search asymmetry within displays containing color- or intensity-coded extraneous items. The asymmetry persisted strongly in the presence of extraneous items that were drawn in a different color (Experiment 1) or a lower contrast (Experiment 2) than the search-relevant items, with the targets favored by the search asymmetry producing highly efficient search. The asymmetry was attenuated but not eliminated when extraneous items were drawn in a higher contrast than search-relevant items (Experiment 3). Results imply that the coding of symbology to exploit visual search asymmetries can facilitate visual search for high-priority items even within color- or intensity-coded displays. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Cross-modal links among vision, audition, and touch in complex environments.

Science.gov (United States)

Ferris, Thomas K; Sarter, Nadine B

2008-02-01

This study sought to determine whether performance effects of cross-modal spatial links that were observed in earlier laboratory studies scale to more complex environments and need to be considered in multimodal interface design. It also revisits the unresolved issue of cross-modal cuing asymmetries. Previous laboratory studies employing simple cues, tasks, and/or targets have demonstrated that the efficiency of processing visual, auditory, and tactile stimuli is affected by the modality, lateralization, and timing of surrounding cues. Very few studies have investigated these cross-modal constraints in the context of more complex environments to determine whether they scale and how complexity affects the nature of cross-modal cuing asymmetries. Amicroworld simulation of battlefield operations with a complex task set and meaningful visual, auditory, and tactile stimuli was used to investigate cuing effects for all cross-modal pairings. Significant asymmetric performance effects of cross-modal spatial links were observed. Auditory cues shortened response latencies for collocated visual targets but visual cues did not do the same for collocated auditory targets. Responses to contralateral (rather than ipsilateral) targets were faster for tactually cued auditory targets and each visual-tactile cue-target combination, suggesting an inhibition-of-return effect. The spatial relationships between multimodal cues and targets significantly affect target response times in complex environments. The performance effects of cross-modal links and the observed cross-modal cuing asymmetries need to be examined in more detail and considered in future interface design. The findings from this study have implications for the design of multimodal and adaptive interfaces and for supporting attention management in complex, data-rich domains.

The efficiency of multimedia learning into old age.

Science.gov (United States)

Van Gerven, Pascal W M; Paas, Fred; Van Merriënboer, Jeroen J G; Hendriks, Maaike; Schmidt, Henk G

2003-12-01

On the basis of a multimodal model of working memory, cognitive load theory predicts that a multimedia-based instructional format leads to a better acquisition of complex subject matter than a purely visual instructional format. This study investigated the extent to which age and instructional format had an impact on training efficiency among both young and old adults. It was hypothesised that studying worked examples that are presented as a narrated animation (multimedia condition) is a more efficient means of complex skill training than studying visually presented worked examples (unimodal condition) and solving conventional problems. Furthermore, it was hypothesised that multimedia-based worked examples are especially helpful for elderly learners, who have to deal with a general decline of working-memory resources, because they address both mode-specific working-memory stores. The sample consisted of 60 young (mean age = 15.98 years) and 60 old adults (mean age = 64.48 years). Participants of both age groups were trained in either a conventional, a unimodal, or a multimedia condition. Subsequently, they had to solve a series of test problems. Dependent variables were perceived cognitive load during the training, performance on the test, and efficiency in terms of the ratio between these two variables. Results showed that for both age groups multimedia-based worked examples were more efficient than the other training formats in that less cognitive load led to at least an equal performance level. Although no difference in the beneficial effect of multimedia learning was found between the age groups, multimedia-based instructions seem promising for the elderly.

Energy efficiency and sustainability of complex biogas systems: A 3-level emergetic evaluation

International Nuclear Information System (INIS)

Chen, Shaoqing; Chen, Bin

2014-01-01

Highlights: • The metabolism of complex biogas system increased from 2000 to 2008. • System renewability has been increased due to biogas utilization. • Electricity, diesels and infrastructure were the most efficient supplies. • All processes were challenged by high transformity and low sustainability. - Abstract: Biogas engineering and the biogas-linked agricultural industries as a whole has been used as both a developmental strategy for rural new emergy and an important part of renewable agriculture revolution in China. In this paper, we proposed a 3-level emergetic evaluation framework to investigate the energy efficiency and sustainability of a complex biogas system (CBS) in South China, comprising agro-industries such as planting, aquaculture, breeding and biogas. The framework is capable of tracking dynamical behaviors of the whole complex system (Level I), transformation processes (Level II) and resource components (Level III) simultaneously. Two new indicators, emergy contribution rate (ECR) and emergy supply efficiency (ESE) were developed to address the contribution and efficiency of resource components within each agro-industrial process. Our findings suggested the metabolism of the CBS were increased from 2000 to 2008, in which planting production was the biggest process in terms of total emergy input, while breeding was the most productive one with its highest total emergy yield. The CBS was under an industry transaction process stimulated by biogas construction, while the traditional agricultural activities still play an important role. For economic input, a trend towards a more renewable regime was found behind the total increase over time. With different preferences for renewable or non-renewable resources, planting and aquaculture production were proved natural donation-reliant, while breeding and biogas were economic input-dependent. Among all the economic inputs, electricity, diesels and infrastructure were the most efficient components

Influence of visual clutter on the effect of navigated safety inspection: a case study on elevator installation.

Science.gov (United States)

Liao, Pin-Chao; Sun, Xinlu; Liu, Mei; Shih, Yu-Nien

2018-01-11

Navigated safety inspection based on task-specific checklists can increase the hazard detection rate, theoretically with interference from scene complexity. Visual clutter, a proxy of scene complexity, can theoretically impair visual search performance, but its impact on the effect of safety inspection performance remains to be explored for the optimization of navigated inspection. This research aims to explore whether the relationship between working memory and hazard detection rate is moderated by visual clutter. Based on a perceptive model of hazard detection, we: (a) developed a mathematical influence model for construction hazard detection; (b) designed an experiment to observe the performance of hazard detection rate with adjusted working memory under different levels of visual clutter, while using an eye-tracking device to observe participants' visual search processes; (c) utilized logistic regression to analyze the developed model under various visual clutter. The effect of a strengthened working memory on the detection rate through increased search efficiency is more apparent in high visual clutter. This study confirms the role of visual clutter in construction-navigated inspections, thus serving as a foundation for the optimization of inspection planning.

TreePics: visualizing trees with pictures

Directory of Open Access Journals (Sweden)

Nicolas Puillandre

2017-09-01

Full Text Available While many programs are available to edit phylogenetic trees, associating pictures with branch tips in an efficient and automatic way is not an available option. Here, we present TreePics, a standalone software that uses a web browser to visualize phylogenetic trees in Newick format and that associates pictures (typically, pictures of the voucher specimens to the tip of each branch. Pictures are visualized as thumbnails and can be enlarged by a mouse rollover. Further, several pictures can be selected and displayed in a separate window for visual comparison. TreePics works either online or in a full standalone version, where it can display trees with several thousands of pictures (depending on the memory available. We argue that TreePics can be particularly useful in a preliminary stage of research, such as to quickly detect conflicts between a DNA-based phylogenetic tree and morphological variation, that may be due to contamination that needs to be removed prior to final analyses, or the presence of species complexes.

TAF11 assembles RISC loading complex to enhance RNAi efficiency

Science.gov (United States)

Liang, Chunyang; Wang, Yibing; Murota, Yukiko; Liu, Xiang; Smith, Dean; Siomi, Mikiko C.; Liu, Qinghua

2015-01-01

SUMMARY Assembly of the RNA-induced silencing complex (RISC) requires formation of the RISC loading complex (RLC), which contains Dicer-2(Dcr-2)-R2D2 complex and recruits duplex siRNA to Ago2 in Drosophila melanogaster. However, the precise composition and action mechanism of Drosophila RLC remain unclear. Here, we identified the missing factor of RLC as TATA-binding protein associated factor 11 (TAF11) by genetic screen. Although an annotated nuclear transcription factor, we found that TAF11 also associated with Dcr-2/R2D2 and localized to cytoplasmic D2 bodies. Consistent with defective RLC assembly in taf11−/− ovary extract, we reconstituted the RLC in vitro using recombinant Dcr-2-R2D2 complex, TAF11, and duplex siRNA. Furthermore, we showed that TAF11 tetramer facilitates Dcr-2-R2D2 tetramerization to enhance siRNA binding and RISC loading activities. Together, our genetic and biochemical studies define the molecular nature of Drosophila RLC and elucidate a novel cytoplasmic function of TAF11 in organizing RLC assembly to enhance RNAi efficiency. PMID:26257286

Data visualization a guide to visual storytelling for libraries

CERN Document Server

2016-01-01

Data Visualization: A Guide to Visual Storytelling for Libraries is a practical guide to the skills and tools needed to create beautiful and meaningful visual stories through data visualization. Learn how to sift through complex datasets to better understand a variety of metrics, such as trends in user behavior and electronic resource usage, return on investment (ROI) and impact metrics, and learning and reference analytics. Sections include: .Identifying and interpreting datasets for visualization .Tools and technologies for creating meaningful visualizations .Case studies in data visualization and dashboards Understanding and communicating trends from your organization s data is essential. Whether you are looking to make more informed decisions by visualizing organizational data, or to tell the story of your library s impact on your community, this book will give you the tools to make it happen."

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

KAUST Repository

Coker, Darren James

2017-04-20

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

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

KAUST Repository

Coker, Darren James; Nowicki, J. P.; Graham, N. A. J.

2017-01-01

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

An efficient hybrid technique in RCS predictions of complex targets at high frequencies

Science.gov (United States)

Algar, María-Jesús; Lozano, Lorena; Moreno, Javier; González, Iván; Cátedra, Felipe

2017-09-01

Most computer codes in Radar Cross Section (RCS) prediction use Physical Optics (PO) and Physical theory of Diffraction (PTD) combined with Geometrical Optics (GO) and Geometrical Theory of Diffraction (GTD). The latter approaches are computationally cheaper and much more accurate for curved surfaces, but not applicable for the computation of the RCS of all surfaces of a complex object due to the presence of caustic problems in the analysis of concave surfaces or flat surfaces in the far field. The main contribution of this paper is the development of a hybrid method based on a new combination of two asymptotic techniques: GTD and PO, considering the advantages and avoiding the disadvantages of each of them. A very efficient and accurate method to analyze the RCS of complex structures at high frequencies is obtained with the new combination. The proposed new method has been validated comparing RCS results obtained for some simple cases using the proposed approach and RCS using the rigorous technique of Method of Moments (MoM). Some complex cases have been examined at high frequencies contrasting the results with PO. This study shows the accuracy and the efficiency of the hybrid method and its suitability for the computation of the RCS at really large and complex targets at high frequencies.

Visual and efficient immunosensor technique for advancing biomedical applications of quantum dots on Salmonella detection and isolation

Science.gov (United States)

Tang, Feng; Pang, Dai-Wen; Chen, Zhi; Shao, Jian-Bo; Xiong, Ling-Hong; Xiang, Yan-Ping; Xiong, Yan; Wu, Kai; Ai, Hong-Wu; Zhang, Hui; Zheng, Xiao-Li; Lv, Jing-Rui; Liu, Wei-Yong; Hu, Hong-Bing; Mei, Hong; Zhang, Zhen; Sun, Hong; Xiang, Yun; Sun, Zi-Yong

2016-02-01

It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab (a solid-phase enrichment system). The selective and chromogenic medium used on this swab can achieve the ultrasensitive amplification of target bacteria and form chromogenic colonies in situ based on a simple biochemical reaction. More importantly, because this swab can serve as an attachment site for the targeted pathogens to immobilize and immunologically capture nanobioprobes, our mAb-conjugated QD bioprobes were successfully applied on the solid-phase enrichment system to capture the fluorescence of targeted colonies under a designed excitation light instrument based on blue light-emitting diodes combined with stereomicroscopy or laser scanning confocal microscopy. Compared with the traditional methods using 4-7 days to isolate Salmonella from the bacterial mixture, this method took only 2 days to do this, and the process of initial screening and preliminary diagnosis can be completed in only one and a half days. Furthermore, the limit of detection can reach as low as 101 cells per mL Salmonella on the background of 105 cells per mL non-Salmonella (Escherichia coli, Proteus mirabilis or Citrobacter freundii, respectively) in experimental samples, and even in human anal ones. The visual and efficient immunosensor technique may be proved to be a favorable alternative for screening and isolating Salmonella in a large number of samples related to public health surveillance.It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here

Brief Report: Effect of Spatial Complexity on Visual Short-Term Memory and Self-Reported Autistic-Like Traits in Typically Developed Individuals

Science.gov (United States)

Takahashi, Junichi; Gyoba, Jiro; Yamawaki, Nozomi

2013-01-01

This report examines effects of the spatial complexity of configurations on visual short-term memory (VSTM) capacity for individuals from the general population differing on autism-spectrum quotient (AQ) scores. During each trial, nine-line segments with various orientations were arrayed in simple or complex configurations and presented in both…

Visual attention

NARCIS (Netherlands)

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

2011-01-01

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

Neural associations of the early retinotopic cortex with the lateral occipital complex during visual perception.

Directory of Open Access Journals (Sweden)

Delong Zhang

Full Text Available Previous studies have demonstrated that the early retinotopic cortex (ERC, i.e., V1/V2/V3 is highly associated with the lateral occipital complex (LOC during visual perception. However, it remains largely unclear how to evaluate their associations in quantitative way. The present study tried to apply a multivariate pattern analysis (MVPA to quantify the neural activity in ERC and its association with that of the LOC when participants saw visual images. To this end, we assessed whether low-level visual features (Gabor features could predict the neural activity in the ERC and LOC according to a voxel-based encoding model (VBEM, and then quantified the association of the neural activity between these regions by using an analogical VBEM. We found that the Gabor features remarkably predicted the activity of the ERC (e.g., the predicted accuracy was 52.5% for a participant instead of that of the LOC (4.2%. Moreover, the MVPA approach can also be used to establish corresponding relationships between the activity patterns in the LOC and those in the ERC (64.2%. In particular, we found that the integration of the Gabor features and LOC visual information could dramatically improve the 'prediction' of ERC activity (88.3%. Overall, the present study provides new evidences for the possibility of quantifying the association of the neural activity between the regions of ERC and LOC. This approach will help to provide further insights into the neural substrates of the visual processing.

Visual Thinking Strategies: Teachers' Reflections on Closely Reading Complex Visual Texts within the Disciplines

Science.gov (United States)

Cappello, Marva; Walker, Nancy T.

2016-01-01

The authors offer a new perspective on close reading that uses a range of multimodal texts to capitalize on the visual nature of contemporary society and to support literacy within the academic disciplines. Specifically, a qualitative study explored teachers' perspectives on the use of Visual Thinking Strategies (VTS), a practice borrowed from…

Visual Ecology and the Development of Visually Guided Behavior in the Cuttlefish

Directory of Open Access Journals (Sweden)

Anne-Sophie Darmaillacq

2017-06-01

Full Text Available Cuttlefish are highly visual animals, a fact reflected in the large size of their eyes and visual-processing centers of their brain. Adults detect their prey visually, navigate using visual cues such as landmarks or the e-vector of polarized light and display intense visual patterns during mating and agonistic encounters. Although much is known about the visual system in adult cuttlefish, few studies have investigated its development and that of visually-guided behavior in juveniles. This review summarizes the results of studies of visual development in embryos and young juveniles. The visual system is the last to develop, as in vertebrates, and is functional before hatching. Indeed, embryonic exposure to prey, shelters or complex background alters postembryonic behavior. Visual acuity and lateralization, and polarization sensitivity improve throughout the first months after hatching. The production of body patterning in juveniles is not the simple stimulus-response process commonly presented in the literature. Rather, it likely requires the complex integration of visual information, and is subject to inter-individual differences. Though the focus of this review is vision in cuttlefish, it is important to note that other senses, particularly sensitivity to vibration and to waterborne chemical signals, also play a role in behavior. Considering the multimodal sensory dimensions of natural stimuli and their integration and processing by individuals offer new exciting avenues of future inquiry.

Visual Ecology and the Development of Visually Guided Behavior in the Cuttlefish.

Science.gov (United States)

Darmaillacq, Anne-Sophie; Mezrai, Nawel; O'Brien, Caitlin E; Dickel, Ludovic

2017-01-01

Cuttlefish are highly visual animals, a fact reflected in the large size of their eyes and visual-processing centers of their brain. Adults detect their prey visually, navigate using visual cues such as landmarks or the e -vector of polarized light and display intense visual patterns during mating and agonistic encounters. Although much is known about the visual system in adult cuttlefish, few studies have investigated its development and that of visually-guided behavior in juveniles. This review summarizes the results of studies of visual development in embryos and young juveniles. The visual system is the last to develop, as in vertebrates, and is functional before hatching. Indeed, embryonic exposure to prey, shelters or complex background alters postembryonic behavior. Visual acuity and lateralization, and polarization sensitivity improve throughout the first months after hatching. The production of body patterning in juveniles is not the simple stimulus-response process commonly presented in the literature. Rather, it likely requires the complex integration of visual information, and is subject to inter-individual differences. Though the focus of this review is vision in cuttlefish, it is important to note that other senses, particularly sensitivity to vibration and to waterborne chemical signals, also play a role in behavior. Considering the multimodal sensory dimensions of natural stimuli and their integration and processing by individuals offer new exciting avenues of future inquiry.

Where's Wally: the influence of visual salience on referring expression generation.

Science.gov (United States)

Clarke, Alasdair D F; Elsner, Micha; Rohde, Hannah

2013-01-01

REFERRING EXPRESSION GENERATION (REG) PRESENTS THE CONVERSE PROBLEM TO VISUAL SEARCH: given a scene and a specified target, how does one generate a description which would allow somebody else to quickly and accurately locate the target?Previous work in psycholinguistics and natural language processing has failed to find an important and integrated role for vision in this task. That previous work, which relies largely on simple scenes, tends to treat vision as a pre-process for extracting feature categories that are relevant to disambiguation. However, the visual search literature suggests that some descriptions are better than others at enabling listeners to search efficiently within complex stimuli. This paper presents a study testing whether participants are sensitive to visual features that allow them to compose such "good" descriptions. Our results show that visual properties (salience, clutter, area, and distance) influence REG for targets embedded in images from the Where's Wally? books. Referring expressions for large targets are shorter than those for smaller targets, and expressions about targets in highly cluttered scenes use more words. We also find that participants are more likely to mention non-target landmarks that are large, salient, and in close proximity to the target. These findings identify a key role for visual salience in language production decisions and highlight the importance of scene complexity for REG.

Efficiency increase of complex production and transport systems management

Directory of Open Access Journals (Sweden)

Kornilov S.

2017-01-01

Full Text Available This article deals with the problem of the reduced efficiency of management in complex production - transport systems due to the lack of co-ordination in the operation of industrial enterprises and transport carrying out their maintenance. The existing transport service schedules for auxiliary departments do not take into account possible changes in operating conditions, the probability of malfunctions and the amount of reserves, which leads to an increase in general production costs. To solve this problem, we propose to use the interval regulation of production and transport processes in all departments of the complex production and transport systems. Also, such regulation involves the determination of traffic service priority. This will allow passing on from the regulated control of production and transport processes to the situational one, adapted to specific conditions, and reducing losses from untimely transport servicing, which will lead to a stores reduction and efficiency increase of the enterprise circulating facilities use. Testing the effectiveness of interval regulation was performed on the system and dynamics simulation model of liquid iron transportation in the oxygen converter shop of the metallurgical enterprise. It was established that the use of interval regulation processes in iron production and its transportation will allow decreasing non-productive downtime by 21% and the amount of the liquid iron in anticipation of recasting in the oxygen converter shop – by 33%. Economical effect of reducing the liquid iron downtime during transportation to the oxygen converter shop will be about 30 million rubles per year.

Visualizing the indefinable: three-dimensional complexity of 'infectious diseases'.

Directory of Open Access Journals (Sweden)

Gabriel Leitner

Full Text Available The words 'infection' and 'inflammation' lack specific definitions. Here, such words are not defined. Instead, the ability to visualize host-microbial interactions was explored.Leukocyte differential counts and four bacterial species (Staphylococcus aureus, Streptococcus dysgalactiae, Staphylococcus chromogenes, and Escherichia coli were determined or isolated in a cross-sectional and randomized study conducted with 611 bovine milk samples. Two paradigms were evaluated: (i the classic one, which measures non-structured (count or percent data; and (ii a method that, using complex data structures, detects and differentiates three-dimensional (3D interactions among lymphocytes (L, macrophages (M, and neutrophils (N.Classic analyses failed to differentiate bacterial-positive (B+ from -negative (B- observations: B- and B+ data overlapped, even when statistical significance was achieved. In contrast, the alternative approach showed distinct patterns, such as perpendicular data inflections, which discriminated microbial-negative/mononuclear cell-predominating (MCP from microbial-positive/phagocyte-predominating (PP subsets. Two PP subcategories were distinguished, as well as PP/culture-negative (false-negative and MCP/culture-positive (false-positive observations. In 3D space, MCP and PP subsets were perpendicular to one another, displaying ≥ 91% specificity or sensitivity. Findings supported five inferences: (i disease is not always ruled out by negative bacterial tests; (ii low total cell counts can coexist with high phagocyte percents; (iii neither positive bacterial isolation nor high cell counts always coincide with PP profiles; (iv statistical significance is not synonymous with discrimination; and (v hidden relationships cannot be detected when simple (non-structured data formats are used and statistical analyses are performed before data subsets are identified, but can be uncovered when complexity is investigated.Pattern recognition

A Multi-Data Source and Multi-Sensor Approach for the 3D Reconstruction and Web Visualization of a Complex Archaelogical Site: The Case Study of “Tolmo De Minateda”

Directory of Open Access Journals (Sweden)

Jose Alberto Torres-Martínez

2016-06-01

Full Text Available The complexity of archaeological sites hinders creation of an integral model using the current Geomatic techniques (i.e., aerial, close-range photogrammetry and terrestrial laser scanner individually. A multi-sensor approach is therefore proposed as the optimal solution to provide a 3D reconstruction and visualization of these complex sites. Sensor registration represents a riveting milestone when automation is required and when aerial and terrestrial datasets must be integrated. To this end, several problems must be solved: coordinate system definition, geo-referencing, co-registration of point clouds, geometric and radiometric homogeneity, etc. The proposed multi-data source and multi-sensor approach is applied to the study case of the “Tolmo de Minateda” archaeological site. A total extension of 9 ha is reconstructed, with an adapted level of detail, by an ultralight aerial platform (paratrike, an unmanned aerial vehicle, a terrestrial laser scanner and terrestrial photogrammetry. Finally, a mobile device (e.g., tablet or smartphone has been used to integrate, optimize and visualize all this information, providing added value to archaeologists and heritage managers who want to use an efficient tool for their works at the site, and even for non-expert users who just want to know more about the archaeological settlement.

Visualization-based decision support for value-driven system design

Science.gov (United States)

Tibor, Elliott

In the past 50 years, the military, communication, and transportation systems that permeate our world, have grown exponentially in size and complexity. The development and production of these systems has seen ballooning costs and increased risk. This is particularly critical for the aerospace industry. The inability to deal with growing system complexity is a crippling force in the advancement of engineered systems. Value-Driven Design represents a paradigm shift in the field of design engineering that has potential to help counteract this trend. The philosophy of Value-Driven Design places the desires of the stakeholder at the forefront of the design process to capture true preferences and reveal system alternatives that were never previously thought possible. Modern aerospace engineering design problems are large, complex, and involve multiple levels of decision-making. To find the best design, the decision-maker is often required to analyze hundreds or thousands of combinations of design variables and attributes. Visualization can be used to support these decisions, by communicating large amounts of data in a meaningful way. Understanding the design space, the subsystem relationships, and the design uncertainties is vital to the advancement of Value-Driven Design as an accepted process for the development of more effective, efficient, robust, and elegant aerospace systems. This research investigates the use of multi-dimensional data visualization tools to support decision-making under uncertainty during the Value-Driven Design process. A satellite design system comprising a satellite, ground station, and launch vehicle is used to demonstrate effectiveness of new visualization methods to aid in decision support during complex aerospace system design. These methods are used to facilitate the exploration of the feasible design space by representing the value impact of system attribute changes and comparing the results of multi-objective optimization formulations

View compensated compression of volume rendered images for remote visualization.

Science.gov (United States)

Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

2009-07-01

Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

Robustness, efficiency, and optimality in the Fenna-Matthews-Olson photosynthetic pigment-protein complex

Energy Technology Data Exchange (ETDEWEB)

Baker, Lewis A.; Habershon, Scott, E-mail: S.Habershon@warwick.ac.uk [Department of Chemistry and Centre for Scientific Computing, University of Warwick, Coventry CV4 7AL (United Kingdom)

2015-09-14

Pigment-protein complexes (PPCs) play a central role in facilitating excitation energy transfer (EET) from light-harvesting antenna complexes to reaction centres in photosynthetic systems; understanding molecular organisation in these biological networks is key to developing better artificial light-harvesting systems. In this article, we combine quantum-mechanical simulations and a network-based picture of transport to investigate how chromophore organization and protein environment in PPCs impacts on EET efficiency and robustness. In a prototypical PPC model, the Fenna-Matthews-Olson (FMO) complex, we consider the impact on EET efficiency of both disrupting the chromophore network and changing the influence of (local and global) environmental dephasing. Surprisingly, we find a large degree of resilience to changes in both chromophore network and protein environmental dephasing, the extent of which is greater than previously observed; for example, FMO maintains EET when 50% of the constituent chromophores are removed, or when environmental dephasing fluctuations vary over two orders-of-magnitude relative to the in vivo system. We also highlight the fact that the influence of local dephasing can be strongly dependent on the characteristics of the EET network and the initial excitation; for example, initial excitations resulting in rapid coherent decay are generally insensitive to the environment, whereas the incoherent population decay observed following excitation at weakly coupled chromophores demonstrates a more pronounced dependence on dephasing rate as a result of the greater possibility of local exciton trapping. Finally, we show that the FMO electronic Hamiltonian is not particularly optimised for EET; instead, it is just one of many possible chromophore organisations which demonstrate a good level of EET transport efficiency following excitation at different chromophores. Overall, these robustness and efficiency characteristics are attributed to the highly

Robustness, efficiency, and optimality in the Fenna-Matthews-Olson photosynthetic pigment-protein complex

International Nuclear Information System (INIS)

Baker, Lewis A.; Habershon, Scott

2015-01-01

Pigment-protein complexes (PPCs) play a central role in facilitating excitation energy transfer (EET) from light-harvesting antenna complexes to reaction centres in photosynthetic systems; understanding molecular organisation in these biological networks is key to developing better artificial light-harvesting systems. In this article, we combine quantum-mechanical simulations and a network-based picture of transport to investigate how chromophore organization and protein environment in PPCs impacts on EET efficiency and robustness. In a prototypical PPC model, the Fenna-Matthews-Olson (FMO) complex, we consider the impact on EET efficiency of both disrupting the chromophore network and changing the influence of (local and global) environmental dephasing. Surprisingly, we find a large degree of resilience to changes in both chromophore network and protein environmental dephasing, the extent of which is greater than previously observed; for example, FMO maintains EET when 50% of the constituent chromophores are removed, or when environmental dephasing fluctuations vary over two orders-of-magnitude relative to the in vivo system. We also highlight the fact that the influence of local dephasing can be strongly dependent on the characteristics of the EET network and the initial excitation; for example, initial excitations resulting in rapid coherent decay are generally insensitive to the environment, whereas the incoherent population decay observed following excitation at weakly coupled chromophores demonstrates a more pronounced dependence on dephasing rate as a result of the greater possibility of local exciton trapping. Finally, we show that the FMO electronic Hamiltonian is not particularly optimised for EET; instead, it is just one of many possible chromophore organisations which demonstrate a good level of EET transport efficiency following excitation at different chromophores. Overall, these robustness and efficiency characteristics are attributed to the highly

Coding Local and Global Binary Visual Features Extracted From Video Sequences

Science.gov (United States)

Baroffio, Luca; Canclini, Antonio; Cesana, Matteo; Redondi, Alessandro; Tagliasacchi, Marco; Tubaro, Stefano

2015-11-01

Binary local features represent an effective alternative to real-valued descriptors, leading to comparable results for many visual analysis tasks, while being characterized by significantly lower computational complexity and memory requirements. When dealing with large collections, a more compact representation based on global features is often preferred, which can be obtained from local features by means of, e.g., the Bag-of-Visual-Word (BoVW) model. Several applications, including for example visual sensor networks and mobile augmented reality, require visual features to be transmitted over a bandwidth-limited network, thus calling for coding techniques that aim at reducing the required bit budget, while attaining a target level of efficiency. In this paper we investigate a coding scheme tailored to both local and global binary features, which aims at exploiting both spatial and temporal redundancy by means of intra- and inter-frame coding. In this respect, the proposed coding scheme can be conveniently adopted to support the Analyze-Then-Compress (ATC) paradigm. That is, visual features are extracted from the acquired content, encoded at remote nodes, and finally transmitted to a central controller that performs visual analysis. This is in contrast with the traditional approach, in which visual content is acquired at a node, compressed and then sent to a central unit for further processing, according to the Compress-Then-Analyze (CTA) paradigm. In this paper we experimentally compare ATC and CTA by means of rate-efficiency curves in the context of two different visual analysis tasks: homography estimation and content-based retrieval. Our results show that the novel ATC paradigm based on the proposed coding primitives can be competitive with CTA, especially in bandwidth limited scenarios.

The Visual Orientation Memory of "Drosophila" Requires Foraging (PKG) Upstream of Ignorant (RSK2) in Ring Neurons of the Central Complex

Science.gov (United States)

Kuntz, Sara; Poeck, Burkhard; Sokolowski, Marla B.; Strauss, Roland

2012-01-01

Orientation and navigation in a complex environment requires path planning and recall to exert goal-driven behavior. Walking "Drosophila" flies possess a visual orientation memory for attractive targets which is localized in the central complex of the adult brain. Here we show that this type of working memory requires the cGMP-dependent protein…

Seeing without the Occipito-Parietal Cortex: Simultagnosia as a Shrinkage of the Attentional Visual Field

Directory of Open Access Journals (Sweden)

François Michel

2004-01-01

Full Text Available Following bi-parietal lesions patient AT showed a severe inability to relocate her attention within a visual field which perimetry proved to be near-normal. An experimental approach with tasks testing visuo-spatial attention demonstrated a shrinkage of A.T.’s attentional visual field. With her visual attention narrowed to a kind of functional tunnel vision, the patient exhibited simultanagnosia (Wolpert, 1924, a symptom previously described in 1909 by Balint under the label of Psychic paralysis of “Gaze”. In striking contrast AT showed an efficient and effortless perception of complex natural scenes, which, according to recent work in normal subjects, necessitate few if any attentional resources.

Visual narratives : free-hand sketch for visual search and navigation of video.

OpenAIRE

James, Stuart

2016-01-01

Humans have an innate ability to communicate visually; the earliest forms of communication were cave drawings, and children can communicate visual descriptions of scenes through drawings well before they can write. Drawings and sketches offer an intuitive and efficient means for communicating visual concepts. Today, society faces a deluge of digital visual content driven by a surge in the generation of video on social media and the online availability of video archives. Mobile devices are...

Tiny but complex - interactive 3D visualization of the interstitial acochlidian gastropod Pseudunela cornuta (Challis, 1970

Directory of Open Access Journals (Sweden)

Heß Martin

2009-09-01

Full Text Available Abstract Background Mesopsammic acochlidians are small, and organ complexity may be strongly reduced (regressive evolution by progenesis, especially in microhedylacean species. The marine interstitial hedylopsacean Pseudunela cornuta (Challis, 1970, however, was suggested as having a complex reproductive system resembling that of much larger, limnic and benthic species. The present study aims to reconstruct the detailed anatomy and true complexity of P. cornuta from serial, semithin histological sections by using modern computer-based 3D visualization with Amira software, and to explain it in an evolutionary context. Results Our results demonstrate considerable discordance with the original species description, which was based solely on paraffin sections. Here, we show that the nervous system of P. cornuta has paired rhinophoral, optic and gastro-oesophageal ganglia, three distinct ganglia on the visceral nerve cord, and a putative osphradial ganglion, while anterior accessory ganglia are absent. The presence of an anal genital cloaca is clearly rejected and the anus, nephropore and gonopore open separately to the exterior; the circulatory and excretory systems are well-differentiated, including a two-chambered heart and a complex kidney with a long, looped nephroduct; the special androdiaulic reproductive system shows two allosperm receptacles, three nidamental glands, a cavity with unknown function, as well as highly complex anterior copulatory organs with two separate glandular and impregnatory systems including a penial stylet that measures approximately a third of the whole length of the preserved specimen. Conclusion In spite of its small body size, the interstitial hermaphroditic P. cornuta shows high complexity regarding all major organ systems; the excretory system is as differentiated as in species of the sister clade, the limnic and much larger Acochlidiidae, and the reproductive system is by far the most elaborated one ever observed

Visual search elicits the electrophysiological marker of visual working memory.

Directory of Open Access Journals (Sweden)

Stephen M Emrich

Full Text Available BACKGROUND: Although limited in capacity, visual working memory (VWM plays an important role in many aspects of visually-guided behavior. Recent experiments have demonstrated an electrophysiological marker of VWM encoding and maintenance, the contralateral delay activity (CDA, which has been shown in multiple tasks that have both explicit and implicit memory demands. Here, we investigate whether the CDA is evident during visual search, a thoroughly-researched task that is a hallmark of visual attention but has no explicit memory requirements. METHODOLOGY/PRINCIPAL FINDINGS: The results demonstrate that the CDA is present during a lateralized search task, and that it is similar in amplitude to the CDA observed in a change-detection task, but peaks slightly later. The changes in CDA amplitude during search were strongly correlated with VWM capacity, as well as with search efficiency. These results were paralleled by behavioral findings showing a strong correlation between VWM capacity and search efficiency. CONCLUSIONS/SIGNIFICANCE: We conclude that the activity observed during visual search was generated by the same neural resources that subserve VWM, and that this activity reflects the maintenance of previously searched distractors.

Generating descriptive visual words and visual phrases for large-scale image applications.

Science.gov (United States)

Zhang, Shiliang; Tian, Qi; Hua, Gang; Huang, Qingming; Gao, Wen

2011-09-01

Bag-of-visual Words (BoWs) representation has been applied for various problems in the fields of multimedia and computer vision. The basic idea is to represent images as visual documents composed of repeatable and distinctive visual elements, which are comparable to the text words. Notwithstanding its great success and wide adoption, visual vocabulary created from single-image local descriptors is often shown to be not as effective as desired. In this paper, descriptive visual words (DVWs) and descriptive visual phrases (DVPs) are proposed as the visual correspondences to text words and phrases, where visual phrases refer to the frequently co-occurring visual word pairs. Since images are the carriers of visual objects and scenes, a descriptive visual element set can be composed by the visual words and their combinations which are effective in representing certain visual objects or scenes. Based on this idea, a general framework is proposed for generating DVWs and DVPs for image applications. In a large-scale image database containing 1506 object and scene categories, the visual words and visual word pairs descriptive to certain objects or scenes are identified and collected as the DVWs and DVPs. Experiments show that the DVWs and DVPs are informative and descriptive and, thus, are more comparable with the text words than the classic visual words. We apply the identified DVWs and DVPs in several applications including large-scale near-duplicated image retrieval, image search re-ranking, and object recognition. The combination of DVW and DVP performs better than the state of the art in large-scale near-duplicated image retrieval in terms of accuracy, efficiency and memory consumption. The proposed image search re-ranking algorithm: DWPRank outperforms the state-of-the-art algorithm by 12.4% in mean average precision and about 11 times faster in efficiency.

Visualizing molecular juggling within a B[subscript 12]-dependent methyltransferase complex

Energy Technology Data Exchange (ETDEWEB)

Kung, Yan; Ando, Nozomi; Doukov, Tzanko I.; Blasiak, Leah C.; Bender, Güne; #351; ; Seravalli, Javier; Ragsdale, Stephen W.; Drennan, Catherine L. (MIT); (Michigan); (UNL)

2013-04-08

Derivatives of vitamin B{sub 12} are used in methyl group transfer in biological processes as diverse as methionine synthesis in humans and CO{sub 2} fixation in acetogenic bacteria. This seemingly straightforward reaction requires large, multimodular enzyme complexes that adopt multiple conformations to alternately activate, protect and perform catalysis on the reactive B{sub 12} cofactor. Crystal structures determined thus far have provided structural information for only fragments of these complexes, inspiring speculation about the overall protein assembly and conformational movements inherent to activity. Here we present X-ray crystal structures of a complete 220 kDa complex that contains all enzymes responsible for B{sub 12}-dependent methyl transfer, namely the corrinoid iron-sulphur protein and its methyltransferase from the model acetogen Moorella thermoacetica. These structures provide the first three-dimensional depiction of all protein modules required for the activation, protection and catalytic steps of B{sub 12}-dependent methyl transfer. In addition, the structures capture B{sub 12} at multiple locations between its 'resting' and catalytic positions, allowing visualization of the dramatic protein rearrangements that enable methyl transfer and identification of the trajectory for B{sub 12} movement within the large enzyme scaffold. The structures are also presented alongside in crystallo spectroscopic data, which confirm enzymatic activity within crystals and demonstrate the largest known conformational movements of proteins in a crystalline state. Taken together, this work provides a model for the molecular juggling that accompanies turnover and helps explain why such an elaborate protein framework is required for such a simple, yet biologically essential reaction.

Techniques for Fault Detection and Visualization of Telemetry Dependence Relationships for Root Cause Fault Analysis in Complex Systems

Science.gov (United States)

Guy, Nathaniel

This thesis explores new ways of looking at telemetry data, from a time-correlative perspective, in order to see patterns within the data that may suggest root causes of system faults. It was thought initially that visualizing an animated Pearson Correlation Coefficient (PCC) matrix for telemetry channels would be sufficient to give new understanding; however, testing showed that the high dimensionality and inability to easily look at change over time in this approach impeded understanding. Different correlative techniques, combined with the time curve visualization proposed by Bach et al (2015), were adapted to visualize both raw telemetry and telemetry data correlations. Review revealed that these new techniques give insights into the data, and an intuitive grasp of data families, which show the effectiveness of this approach for enhancing system understanding and assisting with root cause analysis for complex aerospace systems.

Coupling Visualization and Data Analysis for Knowledge Discovery from Multi-dimensional Scientific Data

International Nuclear Information System (INIS)

Rubel, Oliver; Ahern, Sean; Bethel, E. Wes; Biggin, Mark D.; Childs, Hank; Cormier-Michel, Estelle; DePace, Angela; Eisen, Michael B.; Fowlkes, Charless C.; Geddes, Cameron G.R.; Hagen, Hans; Hamann, Bernd; Huang, Min-Yu; Keranen, Soile V.E.; Knowles, David W.; Hendriks, Chris L. Luengo; Malik, Jitendra; Meredith, Jeremy; Messmer, Peter; Prabhat; Ushizima, Daniela; Weber, Gunther H.; Wu, Kesheng

2010-01-01

Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies 'such as efficient data management' supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach.

Visual patient records

NARCIS (Netherlands)

Luu, M.D.

2015-01-01

Patient information is often complex and fragmented; visualization can help to obtain and communicate insights. To move from paper medical records to interactive and visual patient records is a big challenge. This project aims to move towards this ultimate goal by providing an interactive prototype

Fusion in computer vision understanding complex visual content

CERN Document Server

Ionescu, Bogdan; Piatrik, Tomas

2014-01-01

This book presents a thorough overview of fusion in computer vision, from an interdisciplinary and multi-application viewpoint, describing successful approaches, evaluated in the context of international benchmarks that model realistic use cases. Features: examines late fusion approaches for concept recognition in images and videos; describes the interpretation of visual content by incorporating models of the human visual system with content understanding methods; investigates the fusion of multi-modal features of different semantic levels, as well as results of semantic concept detections, fo

High-efficiency red-light emission from polyfluorenes grafted with cyclometalated iridium complexes and charge transport moiety.

Science.gov (United States)

Chen, Xiwen; Liao, Jin-Long; Liang, Yongmin; Ahmed, M O; Tseng, Hao-En; Chen, Show-An

2003-01-22

We report a new route for the design of electroluminescent polymers by grafting high-efficiency phosphorescent organometallic complexes as dopants and charge transport moieties onto alky side chains of fully conjugated polymers for polymer light-emitting diodes (PLED) with single layer/single polymers. The polymer system studied involves polyfluorene (PF) as the base conjugated polymer, carbazole (Cz) as the charge transport moiety and a source for green emission by forming an electroplex with the PF main chain, and cyclometalated iridium (Ir) complexes as the phosphorescent dopant. Energy transfer from the green Ir complex or an electroplex formed between the fluorene main chain and side-chain carbazole moieties, in addition to that from the PF main chain, to the red Ir complex can significantly enhance the device performance, and a red light-emitting device with the high efficiency 2.8 cd/A at 7 V and 65 cd/m2, comparable to that of the same Ir complex-based OLED, and a broad-band light-emitting device containing blue, green, and red peaks (2.16 cd/A at 9 V) are obtained.

Task complexity as a driver for collaborative learning efficiency: The collective working-memory effect

NARCIS (Netherlands)

Kirschner, Femke; Paas, Fred; Kirschner, Paul A.

2010-01-01

Kirschner, F., Paas, F., & Kirschner, P. A. (2011). Task complexity as a driver for collaborative learning efficiency: The collective working-memory effect. Applied Cognitive Psychology, 25, 615–624. doi: 10.1002/acp.1730.

Towards Online Visualization and Interactive Monitoring of Real-Time CFD Simulations on Commodity Hardware

Directory of Open Access Journals (Sweden)

Nils Koliha

2015-09-01

Full Text Available Real-time rendering in the realm of computational fluid dynamics (CFD in particular and scientific high performance computing (HPC in general is a comparably young field of research, as the complexity of most problems with practical relevance is too high for a real-time numerical simulation. However, recent advances in HPC and the development of very efficient numerical techniques allow running first optimized numerical simulations in or near real-time, which in return requires integrated and optimized visualization techniques that do not affect performance. In this contribution, we present concepts, implementation details and several application examples of a minimally-invasive, efficient visualization tool for the interactive monitoring of 2D and 3D turbulent flow simulations on commodity hardware. The numerical simulations are conducted with ELBE, an efficient lattice Boltzmann environment based on NVIDIA CUDA (Compute Unified Device Architecture, which provides optimized numerical kernels for 2D and 3D computational fluid dynamics with fluid-structure interactions and turbulence.

TAF11 Assembles the RISC Loading Complex to Enhance RNAi Efficiency.

Science.gov (United States)

Liang, Chunyang; Wang, Yibing; Murota, Yukiko; Liu, Xiang; Smith, Dean; Siomi, Mikiko C; Liu, Qinghua

2015-09-03

Assembly of the RNA-induced silencing complex (RISC) requires formation of the RISC loading complex (RLC), which contains the Dicer-2 (Dcr-2)-R2D2 complex and recruits duplex siRNA to Ago2 in Drosophila melanogaster. However, the precise composition and action mechanism of Drosophila RLC remain unclear. Here we identified the missing factor of RLC as TATA-binding protein-associated factor 11 (TAF11) by genetic screen. Although it is an annotated nuclear transcription factor, we found that TAF11 also associated with Dcr-2/R2D2 and localized to cytoplasmic D2 bodies. Consistent with defective RLC assembly in taf11(-/-) ovary extract, we reconstituted the RLC in vitro using the recombinant Dcr-2-R2D2 complex, TAF11, and duplex siRNA. Furthermore, we showed that TAF11 tetramer facilitates Dcr-2-R2D2 tetramerization to enhance siRNA binding and RISC loading activities. Together, our genetic and biochemical studies define the molecular nature of the Drosophila RLC and elucidate a cytoplasmic function of TAF11 in organizing RLC assembly to enhance RNAi efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

Naturally Efficient Emitters: Luminescent Organometallic Complexes Derived from Natural Products

Science.gov (United States)

Zhang, Wen-Hua; Young, David J.

2013-08-01

Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.

Energy and environment efficiency analysis based on an improved environment DEA cross-model: Case study of complex chemical processes

International Nuclear Information System (INIS)

Geng, ZhiQiang; Dong, JunGen; Han, YongMing; Zhu, QunXiong

2017-01-01

Highlights: •An improved environment DEA cross-model method is proposed. •Energy and environment efficiency analysis framework of complex chemical processes is obtained. •This proposed method is efficient in energy-saving and emission reduction of complex chemical processes. -- Abstract: The complex chemical process is a high pollution and high energy consumption industrial process. Therefore, it is very important to analyze and evaluate the energy and environment efficiency of the complex chemical process. Data Envelopment Analysis (DEA) is used to evaluate the relative effectiveness of decision-making units (DMUs). However, the traditional DEA method usually cannot genuinely distinguish the effective and inefficient DMU due to its extreme or unreasonable weight distribution of input and output variables. Therefore, this paper proposes an energy and environment efficiency analysis method based on an improved environment DEA cross-model (DEACM) method. The inputs of the complex chemical process are divided into energy and non-energy inputs. Meanwhile, the outputs are divided into desirable and undesirable outputs. And then the energy and environment performance index (EEPI) based on the cross evaluation is used to represent the overall performance of each DMU. Moreover, the improvement direction of energy-saving and carbon emission reduction of each inefficiency DMU is quantitatively obtained based on the self-evaluation model of the improved environment DEACM. The results show that the improved environment DEACM method has a better effective discrimination than the original DEA method by analyzing the energy and environment efficiency of the ethylene production process in complex chemical processes, and it can obtain the potential of energy-saving and carbon emission reduction of ethylene plants, especially the improvement direction of inefficient DMUs to improve energy efficiency and reduce carbon emission.

Complex Functions with GeoGebra

Science.gov (United States)

Breda, Ana Maria D'azevedo; Dos Santos, José Manuel Dos Santos

2016-01-01

Complex functions, generally feature some interesting peculiarities, seen as extensions of real functions. The visualization of complex functions properties usually requires the simultaneous visualization of two-dimensional spaces. The multiple Windows of GeoGebra, combined with its ability of algebraic computation with complex numbers, allow the…

Coding Local and Global Binary Visual Features Extracted From Video Sequences.

Science.gov (United States)

Baroffio, Luca; Canclini, Antonio; Cesana, Matteo; Redondi, Alessandro; Tagliasacchi, Marco; Tubaro, Stefano

2015-11-01

Binary local features represent an effective alternative to real-valued descriptors, leading to comparable results for many visual analysis tasks while being characterized by significantly lower computational complexity and memory requirements. When dealing with large collections, a more compact representation based on global features is often preferred, which can be obtained from local features by means of, e.g., the bag-of-visual word model. Several applications, including, for example, visual sensor networks and mobile augmented reality, require visual features to be transmitted over a bandwidth-limited network, thus calling for coding techniques that aim at reducing the required bit budget while attaining a target level of efficiency. In this paper, we investigate a coding scheme tailored to both local and global binary features, which aims at exploiting both spatial and temporal redundancy by means of intra- and inter-frame coding. In this respect, the proposed coding scheme can conveniently be adopted to support the analyze-then-compress (ATC) paradigm. That is, visual features are extracted from the acquired content, encoded at remote nodes, and finally transmitted to a central controller that performs the visual analysis. This is in contrast with the traditional approach, in which visual content is acquired at a node, compressed and then sent to a central unit for further processing, according to the compress-then-analyze (CTA) paradigm. In this paper, we experimentally compare the ATC and the CTA by means of rate-efficiency curves in the context of two different visual analysis tasks: 1) homography estimation and 2) content-based retrieval. Our results show that the novel ATC paradigm based on the proposed coding primitives can be competitive with the CTA, especially in bandwidth limited scenarios.

An Empirical Study on Using Visual Embellishments in Visualization.

Science.gov (United States)

Borgo, R; Abdul-Rahman, A; Mohamed, F; Grant, P W; Reppa, I; Floridi, L; Chen, Min

2012-12-01

In written and spoken communications, figures of speech (e.g., metaphors and synecdoche) are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using rhetorical illustrations or embellishments in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual embellishments may aid memorization, visual search and concept comprehension. One major departure from related experiments in the literature is that we make use of a dual-task methodology in our experiment. This design offers an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and lectures). The secondary task introduces "divided attention", and makes the effects of visual embellishments more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual embellishments can help participants better remember the information depicted in visualization. On the other hand, visual embellishments can have a negative impact on the speed of visual search. The results show a complex pattern as to the benefits of visual embellishments in helping participants grasp key concepts from visualization.

Visual explorer facilitator's guide

CERN Document Server

Palus, Charles J

2010-01-01

Grounded in research and practice, the Visual Explorer™ Facilitator's Guide provides a method for supporting collaborative, creative conversations about complex issues through the power of images. The guide is available as a component in the Visual Explorer Facilitator's Letter-sized Set, Visual Explorer Facilitator's Post card-sized Set, Visual Explorer Playing Card-sized Set, and is also available as a stand-alone title for purchase to assist multiple tool users in an organization.

Particle Track Visualization using the MCNP Visual Editor

International Nuclear Information System (INIS)

Schwarz, Randolph A.; Carter, Lee; Brown, Wendi A.

2001-01-01

The Monte Carlo N-Particle (MCNP) visual editor1,2,3 is used throughout the world for displaying and creating complex MCNP geometries. The visual editor combines the Los Alamos MCNP Fortran code with a C front end to provide a visual interface. A big advantage of this approach is that the particle transport routines for MCNP are available to the visual front end. The latest release of the visual editor by Pacific Northwest National Laboratory enables the user to plot transport data points on top of a two-dimensional geometry plot. The user can plot source points, collisions points, surface crossings, and tally contributions. This capability can be used to show where particle collisions are occurring, verify the effectiveness of the particle biasing, or show which collisions contribute to a tally. For a KCODE (criticality source) calculation, the visual editor can be used to plot the source points for specific cycles

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-10-09

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

Effect of carbazole-oxadiazole excited-state complexes on the efficiency of dye-doped light-emitting diodes

Science.gov (United States)

Jiang, Xuezhong; Register, Richard A.; Killeen, Kelly A.; Thompson, Mark E.; Pschenitzka, Florian; Hebner, Thomas R.; Sturm, James C.

2002-05-01

Interactions between hole-transporting carbazole groups and electron-transporting 1,3,4-oxadiazole groups were studied by photoluminescence and electroluminescence (EL) spectroscopy, in blends of poly(N-vinylcarbazole) with 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK:PBD) and in random copolymers with carbazole and oxadiazole groups attached as side chains. Different excited-state complexes form in the blends, which exhibit exciplexes, and in the copolymers, which manifest electroplexes, due to topological constraints on the position of carbazole and oxadiazole units in the polymer. Both types of complex red-shift the EL spectra of the matrices compared with pure PVK homopolymer, although the shift is significantly greater for the electroplex. The presence of these complexes has a profound effect on the external quantum efficiency of dye-doped organic light-emitting diodes employing the blends or copolymers as matrices, as it strongly affects the efficiency of Förster energy transfer from the matrix to the dye. Single-layer devices doped with either coumarin 47 (C47), coumarin 6 (C6), or nile red (NR) were compared. Among the three dye-doped PVK:PBD devices, C6 doping yields the highest efficiency, while NR doping produced the most efficient copolymer devices, consistent with the degree of overlap between the EL spectrum of the matrix material and the absorption spectrum of the dye.

Research on the development efficiency of regional high-end talent in China: A complex network approach.

Science.gov (United States)

Zhang, Zhen; Wang, Minggang; Tian, Lixin; Zhang, Wenbin

2017-01-01

In this paper, based on the panel data of 31 provinces and cities in China from 1991 to 2016, the regional development efficiency matrix of high-end talent is obtained by DEA method, and the matrix is converted into a continuous change of complex networks through the construction of sliding window. Using a series of continuous changes in the complex network topology statistics, the characteristics of regional high-end talent development efficiency system are analyzed. And the results show that the average development efficiency of high-end talent in the western region is at a low level. After 2005, the national regional high-end talent development efficiency network has both short-range relevance and long-range relevance in the evolution process. The central region plays an important intermediary role in the national regional high-end talent development system. And the western region has high clustering characteristics. With the implementation of the high-end talent policies with regional characteristics by different provinces and cities, the relevance of high-end talent development efficiency in various provinces and cities presents a weakening trend, and the geographical characteristics of high-end talent are more and more obvious.

An Efficient Power Estimation Methodology for Complex RISC Processor-based Platforms

OpenAIRE

Rethinagiri , Santhosh Kumar; Ben Atitallah , Rabie; Dekeyser , Jean-Luc; Niar , Smail; Senn , Eric

2012-01-01

International audience; In this contribution, we propose an efficient power estima- tion methodology for complex RISC processor-based plat- forms. In this methodology, the Functional Level Power Analysis (FLPA) is used to set up generic power models for the different parts of the system. Then, a simulation framework based on virtual platform is developed to evalu- ate accurately the activities used in the related power mod- els. The combination of the two parts above leads to a het- erogeneou...

An efficient visual saliency detection model based on Ripplet transform

Indian Academy of Sciences (India)

A Diana Andrushia

human visual attention models is still not well investigated. ... Ripplet transform; visual saliency model; Receiver Operating Characteristics (ROC); .... proposed method has the same resolution as that of an input ... regions are obtained, which are independent of their sizes. ..... impact than those far away from the attention.

High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB

Science.gov (United States)

Asaad, Wael F.; Santhanam, Navaneethan; McClellan, Steven

2013-01-01

Behavioral, psychological, and physiological experiments often require the ability to present sensory stimuli, monitor and record subjects' responses, interface with a wide range of devices, and precisely control the timing of events within a behavioral task. Here, we describe our recent progress developing an accessible and full-featured software system for controlling such studies using the MATLAB environment. Compared with earlier reports on this software, key new features have been implemented to allow the presentation of more complex visual stimuli, increase temporal precision, and enhance user interaction. These features greatly improve the performance of the system and broaden its applicability to a wider range of possible experiments. This report describes these new features and improvements, current limitations, and quantifies the performance of the system in a real-world experimental setting. PMID:23034363

Music Alters Visual Perception

NARCIS (Netherlands)

Jolij, Jacob; Meurs, Maaike

2011-01-01

Background: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e. g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the

Three-dimensional tracking for efficient fire fighting in complex situations

Science.gov (United States)

Akhloufi, Moulay; Rossi, Lucile

2009-05-01

Each year, hundred millions hectares of forests burn causing human and economic losses. For efficient fire fighting, the personnel in the ground need tools permitting the prediction of fire front propagation. In this work, we present a new technique for automatically tracking fire spread in three-dimensional space. The proposed approach uses a stereo system to extract a 3D shape from fire images. A new segmentation technique is proposed and permits the extraction of fire regions in complex unstructured scenes. It works in the visible spectrum and combines information extracted from YUV and RGB color spaces. Unlike other techniques, our algorithm does not require previous knowledge about the scene. The resulting fire regions are classified into different homogenous zones using clustering techniques. Contours are then extracted and a feature detection algorithm is used to detect interest points like local maxima and corners. Extracted points from stereo images are then used to compute the 3D shape of the fire front. The resulting data permits to build the fire volume. The final model is used to compute important spatial and temporal fire characteristics like: spread dynamics, local orientation, heading direction, etc. Tests conducted on the ground show the efficiency of the proposed scheme. This scheme is being integrated with a fire spread mathematical model in order to predict and anticipate the fire behaviour during fire fighting. Also of interest to fire-fighters, is the proposed automatic segmentation technique that can be used in early detection of fire in complex scenes.

Improving the Efficiency and Ease of Healthcare Analysis Through Use of Data Visualization Dashboards.

Science.gov (United States)

Stadler, Jennifer G; Donlon, Kipp; Siewert, Jordan D; Franken, Tessa; Lewis, Nathaniel E

2016-06-01

The digitization of a patient's health record has profoundly impacted medicine and healthcare. The compilation and accessibility of medical history has provided clinicians an unprecedented, holistic account of a patient's conditions, procedures, medications, family history, and social situation. In addition to the bedside benefits, this level of information has opened the door for population-level monitoring and research, the results of which can be used to guide initiatives that are aimed at improving quality of care. Cerner Corporation partners with health systems to help guide population management and quality improvement projects. With such an enormous and diverse client base-varying in geography, size, organizational structure, and analytic needs-discerning meaning in the data and how they fit with that particular hospital's goals is a slow, difficult task that requires clinical, statistical, and technical literacy. This article describes the development of dashboards for efficient data visualization at the healthcare facility level. Focusing on two areas with broad clinical importance, sepsis patient outcomes and 30-day hospital readmissions, dashboards were developed with the goal of aggregating data and providing meaningful summary statistics, highlighting critical performance metrics, and providing easily digestible visuals that can be understood by a wide range of personnel with varying levels of skill and areas of expertise. These internal-use dashboards have allowed associates in multiple roles to perform a quick and thorough assessment on a hospital of interest by providing the data to answer necessary questions and to identify important trends or opportunities. This automation of a previously manual process has greatly increased efficiency, saving hours of work time per hospital analyzed. Additionally, the dashboards have standardized the analysis process, ensuring use of the same metrics and processes so that overall themes can be compared across

EDITORIAL: Focus on Visualization in Physics FOCUS ON VISUALIZATION IN PHYSICS

Science.gov (United States)

Sanders, Barry C.; Senden, Tim; Springel, Volker

2008-12-01

Advances in physics are intimately connected with developments in a new technology, the telescope, precision clocks, even the computer all have heralded a shift in thinking. These landmark developments open new opportunities accelerating research and in turn new scientific directions. These technological drivers often correspond to new instruments, but equally might just as well flag a new mathematical tool, an algorithm or even means to visualize physics in a new way. Early on in this twenty-first century, scientific communities are just starting to explore the potential of digital visualization. Whether visualization is used to represent and communicate complex concepts, or to understand and interpret experimental data, or to visualize solutions to complex dynamical equations, the basic tools of visualization are shared in each of these applications and implementations. High-performance computing exemplifies the integration of visualization with leading research. Visualization is an indispensable tool for analyzing and interpreting complex three-dimensional dynamics as well as to diagnose numerical problems in intricate parallel calculation algorithms. The effectiveness of visualization arises by exploiting the unmatched capability of the human eye and visual cortex to process the large information content of images. In a brief glance, we recognize patterns or identify subtle features even in noisy data, something that is difficult or impossible to achieve with more traditional forms of data analysis. Importantly, visualizations guide the intuition of researchers and help to comprehend physical phenomena that lie far outside of direct experience. In fact, visualizations literally allow us to see what would otherwise remain completely invisible. For example, artificial imagery created to visualize the distribution of dark matter in the Universe has been instrumental to develop the notion of a cosmic web, and for helping to establish the current standard model of

User's manual about visualizing debugger, vdebug

International Nuclear Information System (INIS)

Matsuda, Katsuyuki; Takemiya, Hiroshi; Kawasaki, Takuji

1998-12-01

We developed a visualizing debugger, vdebug, which works in cooperation with the visualization system AVS and source level debuggers (gdb, dbx, and ladebug), whereby we can visualize any array data without recompiling, and find errors in programs efficiently. This report is user's manual about a visualizing debugger, vdebug, and describes its usage and examples. (author)

Efficient transmission of subthreshold signals in complex networks of spiking neurons.

Science.gov (United States)

Torres, Joaquin J; Elices, Irene; Marro, J

2015-01-01

We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances--that naturally balances the network with excitatory and inhibitory synapses--and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest.

Efficient transmission of subthreshold signals in complex networks of spiking neurons.

Directory of Open Access Journals (Sweden)

Joaquin J Torres

Full Text Available We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances--that naturally balances the network with excitatory and inhibitory synapses--and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest.

Improving Design Communication: Advanced Visualization

National Research Council Canada - National Science Library

Adeoye, Blessing

2001-01-01

.... While design professionals may use similar visual modes (lines, text, graphic symbols, etc.) to represent and communicate concepts in complex drawing tasks, similar visual modes may be used ambiguously across disciplines...

Visualizing the Indefinable: Three-Dimensional Complexity of ‘Infectious Diseases’

Science.gov (United States)

Leitner, Gabriel; Blum, Shlomo E.; Rivas, Ariel L.

2015-01-01

Background The words ‘infection’ and ‘inflammation’ lack specific definitions. Here, such words are not defined. Instead, the ability to visualize host-microbial interactions was explored. Methods Leukocyte differential counts and four bacterial species (Staphylococcus aureus, Streptococcus dysgalactiae, Staphylococcus chromogenes, and Escherichia coli) were determined or isolated in a cross-sectional and randomized study conducted with 611 bovine milk samples. Two paradigms were evaluated: (i) the classic one, which measures non-structured (count or percent) data; and (ii) a method that, using complex data structures, detects and differentiates three-dimensional (3D) interactions among lymphocytes (L), macrophages (M), and neutrophils (N). Results Classic analyses failed to differentiate bacterial-positive (B+) from –negative (B−) observations: B− and B+ data overlapped, even when statistical significance was achieved. In contrast, the alternative approach showed distinct patterns, such as perpendicular data inflections, which discriminated microbial-negative/mononuclear cell-predominating (MCP) from microbial-positive/phagocyte-predominating (PP) subsets. Two PP subcategories were distinguished, as well as PP/culture-negative (false-negative) and MCP/culture-positive (false-positive) observations. In 3D space, MCP and PP subsets were perpendicular to one another, displaying ≥91% specificity or sensitivity. Findings supported five inferences: (i) disease is not always ruled out by negative bacterial tests; (ii) low total cell counts can coexist with high phagocyte percents; (iii) neither positive bacterial isolation nor high cell counts always coincide with PP profiles; (iv) statistical significance is not synonymous with discrimination; and (v) hidden relationships cannot be detected when simple (non-structured) data formats are used and statistical analyses are performed before data subsets are identified, but can be uncovered when complexity is

Looking to Learn: The Effects of Visual Guidance on Observational Learning of the Golf Swing.

Science.gov (United States)

D'Innocenzo, Giorgia; Gonzalez, Claudia C; Williams, A Mark; Bishop, Daniel T

2016-01-01

Skilled performers exhibit more efficient gaze patterns than less-skilled counterparts do and they look more frequently at task-relevant regions than at superfluous ones. We examine whether we may guide novices' gaze towards relevant regions during action observation in order to facilitate their learning of a complex motor skill. In a Pre-test-Post-test examination of changes in their execution of the full golf swing, 21 novices viewed one of three videos at intervention: i) a skilled golfer performing 10 swings (Free Viewing, FV); ii) the same video with transient colour cues superimposed to highlight key features of the setup (Visual Guidance; VG); iii) or a History of Golf video (Control). Participants in the visual guidance group spent significantly more time looking at cued areas than did the other two groups, a phenomenon that persisted after the cues had been removed. Moreover, the visual guidance group improved their swing execution at Post-test and on a Retention test one week later. Our results suggest that visual guidance to cued areas during observational learning of complex motor skills may accelerate acquisition of the skill.

A visual approach to efficient analysis and quantification of ductile iron and reinforced sprayed concrete.

Science.gov (United States)

Fritz, Laura; Hadwiger, Markus; Geier, Georg; Pittino, Gerhard; Gröller, M Eduard

2009-01-01

This paper describes advanced volume visualization and quantification for applications in non-destructive testing (NDT), which results in novel and highly effective interactive workflows for NDT practitioners. We employ a visual approach to explore and quantify the features of interest, based on transfer functions in the parameter spaces of specific application scenarios. Examples are the orientations of fibres or the roundness of particles. The applicability and effectiveness of our approach is illustrated using two specific scenarios of high practical relevance. First, we discuss the analysis of Steel Fibre Reinforced Sprayed Concrete (SFRSpC). We investigate the orientations of the enclosed steel fibres and their distribution, depending on the concrete's application direction. This is a crucial step in assessing the material's behavior under mechanical stress, which is still in its infancy and therefore a hot topic in the building industry. The second application scenario is the designation of the microstructure of ductile cast irons with respect to the contained graphite. This corresponds to the requirements of the ISO standard 945-1, which deals with 2D metallographic samples. We illustrate how the necessary analysis steps can be carried out much more efficiently using our system for 3D volumes. Overall, we show that a visual approach with custom transfer functions in specific application domains offers significant benefits and has the potential of greatly improving and optimizing the workflows of domain scientists and engineers.

Evidence of gradual loss of precision for simple features and complex objects in visual working memory.

Science.gov (United States)

Rademaker, Rosanne L; Park, Young Eun; Sack, Alexander T; Tong, Frank

2018-03-01

Previous studies have suggested that people can maintain prioritized items in visual working memory for many seconds, with negligible loss of information over time. Such findings imply that working memory representations are robust to the potential contaminating effects of internal noise. However, once visual information is encoded into working memory, one might expect it to inevitably begin degrading over time, as this actively maintained information is no longer tethered to the original perceptual input. Here, we examined this issue by evaluating working memory for single central presentations of an oriented grating, color patch, or face stimulus, across a range of delay periods (1, 3, 6, or 12 s). We applied a mixture-model analysis to distinguish changes in memory precision over time from changes in the frequency of outlier responses that resemble random guesses. For all 3 types of stimuli, participants exhibited a clear and consistent decline in the precision of working memory as a function of temporal delay, as well as a modest increase in guessing-related responses for colored patches and face stimuli. We observed a similar loss of precision over time while controlling for temporal distinctiveness. Our results demonstrate that visual working memory is far from lossless: while basic visual features and complex objects can be maintained in a quite stable manner over time, these representations are still subject to noise accumulation and complete termination. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

An automated paradigm for Drosophila visual psychophysics.

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Oliver Evans

Full Text Available BACKGROUND: Mutations that cause learning and memory defects in Drosophila melanogaster have been found to also compromise visual responsiveness and attention. A better understanding of attention-like defects in such Drosophila mutants therefore requires a more detailed characterization of visual responsiveness across a range of visual parameters. METHODOLOGY/PRINCIPAL FINDINGS: We designed an automated behavioral paradigm for efficiently dissecting visual responsiveness in Drosophila. Populations of flies walk through multiplexed serial choice mazes while being exposed to moving visuals displayed on computer monitors, and infra-red fly counters at the end of each maze automatically score the responsiveness of a strain. To test our new design, we performed a detailed comparison between wild-type flies and a learning and memory mutant, dunce(1. We first confirmed that the learning mutant dunce(1 displays increased responsiveness to a black/green moving grating compared to wild type in this new design. We then extended this result to explore responses to a wide range of psychophysical parameters for moving gratings (e.g., luminosity, contrast, spatial frequency, velocity as well as to a different stimulus, moving dots. Finally, we combined these visuals (gratings versus dots in competition to investigate how dunce(1 and wild-type flies respond to more complex and conflicting motion effects. CONCLUSIONS/SIGNIFICANCE: We found that dunce(1 responds more strongly than wild type to high contrast and highly structured motion. This effect was found for simple gratings, dots, and combinations of both stimuli presented in competition.

Flow visualization in models of high speed centrifugal separators

International Nuclear Information System (INIS)

Lagerstedt, T.; Nabo, O.

1987-01-01

The modern centrifugal separator is a fluid machine where the high ''G'' forces set up by rotation are utilized to separate phases of different densities. The fluid dynamics of the separator is complex and poorly known. Hundred years of (practical) experience has, however, turned the separator into an efficient machine. The present report shows how straight forward visualization experiments in model rigs provide valuable information on the flow inside the separator. The report concentrates on describing the flow between the closely spaced discs in a separator disc stack

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets.

Science.gov (United States)

Bola, Łukasz; Radziun, Dominika; Siuda-Krzywicka, Katarzyna; Sowa, Joanna E; Paplińska, Małgorzata; Sumera, Ewa; Szwed, Marcin

2017-01-01

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a "normal" script (e.g., Cyrillic). Using a lexical decision task, we examined Visual Braille reading speed and efficiency in sighted Braille teachers. As a control, we tested learners of a natural visual script, Cyrillic. Both groups participated in a two semester course of either visual Braille or Russian while their reading speed and accuracy was tested at regular intervals. The results show that visual Braille reading is slow, prone to errors and highly serial, even in Braille readers with years of prior reading experience. Although subjects showed some improvements in their visual Braille reading accuracy and speed following the course, the effect of word length on reading speed (typically observed in beginning readers) was remained very sizeable through all testing sessions. These results are in stark contrast to Cyrillic, a natural script, where only 3 months of learning were sufficient to achieve relative proficiency. Taken together, these results suggest that visual features such as line junctions and their combinations might be necessary for efficient reading.

Seeing More by Showing Less: Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization

OpenAIRE

Tax, Chantal M. W.; Chamberland, Maxime; van Stralen, Marijn; Viergever, Max A.; Whittingstall, Kevin; Fortin, David; Descoteaux, Maxime; Leemans, Alexander

2015-01-01

Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI) approaches that can also model "crossing fibers", the complexity of the fiber network as reconstructed with tractography has increased tremendously. Many pathways interdigitate and overlap, which hampers an unequivocal 3D visualization of the network and impedes an efficient study of...

VisComposer: A Visual Programmable Composition Environment for Information Visualization

Directory of Open Access Journals (Sweden)

Honghui Mei

2018-03-01

Full Text Available As the amount of data being collected has increased, the need for tools that can enable the visual exploration of data has also grown. This has led to the development of a variety of widely used programming frameworks for information visualization. Unfortunately, such frameworks demand comprehensive visualization and coding skills and require users to develop visualization from scratch. An alternative is to create interactive visualization design environments that require little to no programming. However, these tools only supports a small portion of visual forms.We present a programmable integrated development environment (IDE, VisComposer, that supports the development of expressive visualization using a drag-and-drop visual interface. VisComposer exposes the programmability by customizing desired components within a modularized visualization composition pipeline, effectively balancing the capability gap between expert coders and visualization artists. The implemented system empowers users to compose comprehensive visualizations with real-time preview and optimization features, and supports prototyping, sharing and reuse of the effects by means of an intuitive visual composer. Visual programming and textual programming integrated in our system allow users to compose more complex visual effects while retaining the simplicity of use. We demonstrate the performance of VisComposer with a variety of examples and an informal user evaluation. Keywords: Information Visualization, Visualization authoring, Interactive development environment

Complex scenes and situations visualization in hierarchical learning algorithm with dynamic 3D NeoAxis engine

Science.gov (United States)

Graham, James; Ternovskiy, Igor V.

2013-06-01

We applied a two stage unsupervised hierarchical learning system to model complex dynamic surveillance and cyber space monitoring systems using a non-commercial version of the NeoAxis visualization software. The hierarchical scene learning and recognition approach is based on hierarchical expectation maximization, and was linked to a 3D graphics engine for validation of learning and classification results and understanding the human - autonomous system relationship. Scene recognition is performed by taking synthetically generated data and feeding it to a dynamic logic algorithm. The algorithm performs hierarchical recognition of the scene by first examining the features of the objects to determine which objects are present, and then determines the scene based on the objects present. This paper presents a framework within which low level data linked to higher-level visualization can provide support to a human operator and be evaluated in a detailed and systematic way.

Improved motion contrast and processing efficiency in OCT angiography using complex-correlation algorithm

International Nuclear Information System (INIS)

Guo, Li; Li, Pei; Pan, Cong; Cheng, Yuxuan; Ding, Zhihua; Li, Peng; Liao, Rujia; Hu, Weiwei; Chen, Zhong

2016-01-01

The complex-based OCT angiography (Angio-OCT) offers high motion contrast by combining both the intensity and phase information. However, due to involuntary bulk tissue motions, complex-valued OCT raw data are processed sequentially with different algorithms for correcting bulk image shifts (BISs), compensating global phase fluctuations (GPFs) and extracting flow signals. Such a complicated procedure results in massive computational load. To mitigate such a problem, in this work, we present an inter-frame complex-correlation (CC) algorithm. The CC algorithm is suitable for parallel processing of both flow signal extraction and BIS correction, and it does not need GPF compensation. This method provides high processing efficiency and shows superiority in motion contrast. The feasibility and performance of the proposed CC algorithm is demonstrated using both flow phantom and live animal experiments. (paper)

Utilizing Visual Effects Software for Efficient and Flexible Isostatic Adjustment Modelling

Science.gov (United States)

Meldgaard, A.; Nielsen, L.; Iaffaldano, G.

2017-12-01

The isostatic adjustment signal generated by transient ice sheet loading is an important indicator of past ice sheet extent and the rheological constitution of the interior of the Earth. Finite element modelling has proved to be a very useful tool in these studies. We present a simple numerical model for 3D visco elastic Earth deformation and a new approach to the design of such models utilizing visual effects software designed for the film and game industry. The software package Houdini offers an assortment of optimized tools and libraries which greatly facilitate the creation of efficient numerical algorithms. In particular, we make use of Houdini's procedural work flow, the SIMD programming language VEX, Houdini's sparse matrix creation and inversion libraries, an inbuilt tetrahedralizer for grid creation, and the user interface, which facilitates effortless manipulation of 3D geometry. We mitigate many of the time consuming steps associated with the authoring of efficient algorithms from scratch while still keeping the flexibility that may be lost with the use of commercial dedicated finite element programs. We test the efficiency of the algorithm by comparing simulation times with off-the-shelf solutions from the Abaqus software package. The algorithm is tailored for the study of local isostatic adjustment patterns, in close vicinity to present ice sheet margins. In particular, we wish to examine possible causes for the considerable spatial differences in the uplift magnitude which are apparent from field observations in these areas. Such features, with spatial scales of tens of kilometres, are not resolvable with current global isostatic adjustment models, and may require the inclusion of local topographic features. We use the presented algorithm to study a near field area where field observations are abundant, namely, Disko Bay in West Greenland with the intention of constraining Earth parameters and ice thickness. In addition, we assess how local

An integrative view of storage of low- and high-level visual dimensions in visual short-term memory.

Science.gov (United States)

Magen, Hagit

2017-03-01

Efficient performance in an environment filled with complex objects is often achieved through the temporal maintenance of conjunctions of features from multiple dimensions. The most striking finding in the study of binding in visual short-term memory (VSTM) is equal memory performance for single features and for integrated multi-feature objects, a finding that has been central to several theories of VSTM. Nevertheless, research on binding in VSTM focused almost exclusively on low-level features, and little is known about how items from low- and high-level visual dimensions (e.g., colored manmade objects) are maintained simultaneously in VSTM. The present study tested memory for combinations of low-level features and high-level representations. In agreement with previous findings, Experiments 1 and 2 showed decrements in memory performance when non-integrated low- and high-level stimuli were maintained simultaneously compared to maintaining each dimension in isolation. However, contrary to previous findings the results of Experiments 3 and 4 showed decrements in memory performance even when integrated objects of low- and high-level stimuli were maintained in memory, compared to maintaining single-dimension objects. Overall, the results demonstrate that low- and high-level visual dimensions compete for the same limited memory capacity, and offer a more comprehensive view of VSTM.

Spatial complexity of carcass location influences vertebrate scavenger efficiency and species composition.

Science.gov (United States)

Smith, Joshua B; Laatsch, Lauren J; Beasley, James C

2017-08-31

Scavenging plays an important role in shaping communities through inter- and intra-specific interactions. Although vertebrate scavenger efficiency and species composition is likely influenced by the spatial complexity of environments, heterogeneity in carrion distribution has largely been disregarded in scavenging studies. We tested this hypothesis by experimentally placing juvenile bird carcasses on the ground and in nests in trees to simulate scenarios of nestling bird carrion availability. We used cameras to record scavengers removing carcasses and elapsed time to removal. Carrion placed on the ground was scavenged by a greater diversity of vertebrates and at > 2 times the rate of arboreal carcasses, suggesting arboreal carrion may represent an important resource to invertebrate scavengers, particularly in landscapes with efficient vertebrate scavenging communities. Nonetheless, six vertebrate species scavenged arboreal carcasses. Rat snakes (Elaphe obsolete), which exclusively scavenged from trees, and turkey vultures (Cathartes aura) were the primary scavengers of arboreal carrion, suggesting such resources are potentially an important pathway of nutrient acquisition for some volant and scansorial vertebrates. Our results highlight the intricacy of carrion-derived food web linkages, and how consideration of spatial complexity in carcass distribution (i.e., arboreal) may reveal important pathways of nutrient acquisition by invertebrate and vertebrate scavenging guilds.

Customizable Time-Oriented Visualizations

DEFF Research Database (Denmark)

Kuhail, Mohammad Amin; Pantazos, Kostas; Lauesen, Søren

2012-01-01

Most commercial visualization tools support an easy and quick creation of conventional time-oriented visualizations such as line charts, but customization is limited. In contrast, some academic visualization tools and programming languages support the creation of some customizable time......-oriented visualizations but it is time consuming and hard. To combine efficiency, the effort required to develop a visualization, and customizability, the ability to tailor a visualization, we developed time-oriented building blocks that address the specifics of time (e.g. linear vs. cyclic or point-based vs. interval......-based) and consist of inner customizable parts (e.g. ticks). A combination of the time-oriented and other primitive graphical building blocks allowed the creation of several customizable advanced time-oriented visualizations. The appearance and behavior of the blocks are specified using spreadsheet-like formulas. We...

CONTROLLING AS A MECHANISM TO INCREASE THE EFFICIENCY OF MANAGEMENT ENTERPRISES OF FUEL-ENERGY COMPLEX

Directory of Open Access Journals (Sweden)

M. A. Ostashkin

2013-01-01

Full Text Available This article discusses the possibility of application of controlling as mechanism of increasing the efficiency of management of enterprises of fuel- energy complex. The research was conducted on the materials of the JSC «Gazprom».

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

Science.gov (United States)

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

2015-08-01

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

Visual attention.

Science.gov (United States)

Evans, Karla K; Horowitz, Todd S; Howe, Piers; Pedersini, Roccardo; Reijnen, Ester; Pinto, Yair; Kuzmova, Yoana; Wolfe, Jeremy M

2011-09-01

A typical visual scene we encounter in everyday life is complex and filled with a huge amount of perceptual information. The term, 'visual attention' describes a set of mechanisms that limit some processing to a subset of incoming stimuli. Attentional mechanisms shape what we see and what we can act upon. They allow for concurrent selection of some (preferably, relevant) information and inhibition of other information. This selection permits the reduction of complexity and informational overload. Selection can be determined both by the 'bottom-up' saliency of information from the environment and by the 'top-down' state and goals of the perceiver. Attentional effects can take the form of modulating or enhancing the selected information. A central role for selective attention is to enable the 'binding' of selected information into unified and coherent representations of objects in the outside world. In the overview on visual attention presented here we review the mechanisms and consequences of selection and inhibition over space and time. We examine theoretical, behavioral and neurophysiologic work done on visual attention. We also discuss the relations between attention and other cognitive processes such as automaticity and awareness. WIREs Cogni Sci 2011 2 503-514 DOI: 10.1002/wcs.127 For further resources related to this article, please visit the WIREs website. Copyright © 2011 John Wiley & Sons, Ltd.

Critical visualization: a case for rethinking how we visualize risk and security

OpenAIRE

Hall, Peter; Heath, Claude; Coles-Kemp, Lizzie

2015-01-01

In an era of high-profile hacks, information leaks and cybercrime, cybersecurity is the focus of much corporate and state-funded research. Data visualization is regarded as an important tool in the detection and prediction of risk and vulnerability in cybersecurity, but discussion tends to remain at the level of the usability of visualization tools and how to reduce the cognitive load on the consumers of the visualizations. This focus is rooted in a desire to simplify the complexity of cybers...

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

Directory of Open Access Journals (Sweden)

Guozheng Yao

2010-03-01

Full Text Available Abstract Background What kind of neural computation is actually performed by the primary visual cortex and how is this represented mathematically at the system level? It is an important problem in the visual information processing, but has not been well answered. In this paper, according to our understanding of retinal organization and parallel multi-channel topographical mapping between retina and primary visual cortex V1, we divide an image into orthogonal and orderly array of image primitives (or patches, in which each patch will evoke activities of simple cells in V1. From viewpoint of information processing, this activated process, essentially, involves optimal detection and optimal matching of receptive fields of simple cells with features contained in image patches. For the reconstruction of the visual image in the visual cortex V1 based on the principle of minimum mean squares error, it is natural to use the inner product expression in neural computation, which then is transformed into matrix form. Results The inner product is carried out by using Kronecker product between patches and function architecture (or functional column in localized and oriented neural computing. Compared with Fourier Transform, the mathematical description of Kronecker product is simple and intuitive, so is the algorithm more suitable for neural computation of visual cortex V1. Results of computer simulation based on two-dimensional Gabor pyramid wavelets show that the theoretical analysis and the proposed model are reasonable. Conclusions Our results are: 1. The neural computation of the retinal image in cortex V1 can be expressed to Kronecker product operation and its matrix form, this algorithm is implemented by the inner operation between retinal image primitives and primary visual cortex's column. It has simple, efficient and robust features, which is, therefore, such a neural algorithm, which can be completed by biological vision. 2. It is more suitable

Examining Practice in Secondary Visual Arts Education

Science.gov (United States)

Mitchell, Donna Mathewson

2015-01-01

Teaching in secondary visual arts classrooms is complex and challenging work. While it is implicated in much research, the complexity of the lived experience of secondary visual arts teaching has rarely been the subject of sustained and synthesized research. In this paper, the potential of practice as a concept to examine and represent secondary…

Highly efficient photocatalytic hydrogen evolution from nickel quinolinethiolate complexes under visible light irradiation

Science.gov (United States)

Rao, Heng; Yu, Wen-Qian; Zheng, Hui-Qin; Bonin, Julien; Fan, Yao-Ting; Hou, Hong-Wei

2016-08-01

Earth-abundant metal complexes have emerged as promising surrogates of platinum for catalyzing the hydrogen evolution reaction (HER). In this study, we report the design and synthesis of two novel nickel quinolinethiolate complexes, namely [Ni(Hqt)2(4, 4‧-Z-2, 2‧-bpy)] (Hqt = 8-quinolinethiol, Z = sbnd H [1] or sbnd CH3 [2], bpy = bipyridine). An efficient three-component photocatalytic homogeneous system for hydrogen generation working under visible light irradiation was constructed by using the target complexes as catalysts, triethylamine (TEA) as sacrificial electron donor and xanthene dyes as photosensitizer. We obtain turnover numbers (TON, vs. catalyst) for H2 evolution of 5923/7634 under the optimal conditions with 5.0 × 10-6 M complex 1/2 respectively, 1.0 × 10-3 M fluorescein and 5% (v/v) TEA at pH 12.3 in EtOH/H2O (1:1, v/v) mixture after 8 h irradiation (λ > 420 nm). We discuss the mechanism of H2 evolution in the homogeneous photocatalytic system based on fluorescence spectrum and cyclic voltammetry data.

StreamExplorer: A Multi-Stage System for Visually Exploring Events in Social Streams.

Science.gov (United States)

Wu, Yingcai; Chen, Zhutian; Sun, Guodao; Xie, Xiao; Cao, Nan; Liu, Shixia; Cui, Weiwei

2017-10-18

Analyzing social streams is important for many applications, such as crisis management. However, the considerable diversity, increasing volume, and high dynamics of social streams of large events continue to be significant challenges that must be overcome to ensure effective exploration. We propose a novel framework by which to handle complex social streams on a budget PC. This framework features two components: 1) an online method to detect important time periods (i.e., subevents), and 2) a tailored GPU-assisted Self-Organizing Map (SOM) method, which clusters the tweets of subevents stably and efficiently. Based on the framework, we present StreamExplorer to facilitate the visual analysis, tracking, and comparison of a social stream at three levels. At a macroscopic level, StreamExplorer uses a new glyph-based timeline visualization, which presents a quick multi-faceted overview of the ebb and flow of a social stream. At a mesoscopic level, a map visualization is employed to visually summarize the social stream from either a topical or geographical aspect. At a microscopic level, users can employ interactive lenses to visually examine and explore the social stream from different perspectives. Two case studies and a task-based evaluation are used to demonstrate the effectiveness and usefulness of StreamExplorer.Analyzing social streams is important for many applications, such as crisis management. However, the considerable diversity, increasing volume, and high dynamics of social streams of large events continue to be significant challenges that must be overcome to ensure effective exploration. We propose a novel framework by which to handle complex social streams on a budget PC. This framework features two components: 1) an online method to detect important time periods (i.e., subevents), and 2) a tailored GPU-assisted Self-Organizing Map (SOM) method, which clusters the tweets of subevents stably and efficiently. Based on the framework, we present Stream

Visual attention mitigates information loss in small- and large-scale neural codes

Science.gov (United States)

Sprague, Thomas C; Saproo, Sameer; Serences, John T

2015-01-01

Summary The visual system transforms complex inputs into robust and parsimonious neural codes that efficiently guide behavior. Because neural communication is stochastic, the amount of encoded visual information necessarily decreases with each synapse. This constraint requires processing sensory signals in a manner that protects information about relevant stimuli from degradation. Such selective processing – or selective attention – is implemented via several mechanisms, including neural gain and changes in tuning properties. However, examining each of these effects in isolation obscures their joint impact on the fidelity of stimulus feature representations by large-scale population codes. Instead, large-scale activity patterns can be used to reconstruct representations of relevant and irrelevant stimuli, providing a holistic understanding about how neuron-level modulations collectively impact stimulus encoding. PMID:25769502

Creativity, Complexity, and Precision: Information Visualization for (Landscape) Architecture

DEFF Research Database (Denmark)

Buscher, Monika; Christensen, Michael; Mogensen, Preben Holst

2000-01-01

Drawing on ethnographic studies of (landscape) architects at work, this paper presents a human-centered approach to information visualization. A 3D collaborative electronic workspace allows people to configure, save and browse arrangements of heterogeneous work materials. Spatial arrangements...... and links are created and maintained as an integral part of ongoing work with `live' documents and objects. The result is an extension of the physical information space of the architects' studio that utilizes the potential of electronic data storage, visualization and network technologies to support work...... with information in context...

An integrated theory of attention and decision making in visual signal detection.

Science.gov (United States)

Smith, Philip L; Ratcliff, Roger

2009-04-01

The simplest attentional task, detecting a cued stimulus in an otherwise empty visual field, produces complex patterns of performance. Attentional cues interact with backward masks and with spatial uncertainty, and there is a dissociation in the effects of these variables on accuracy and on response time. A computational theory of performance in this task is described. The theory links visual encoding, masking, spatial attention, visual short-term memory (VSTM), and perceptual decision making in an integrated dynamic framework. The theory assumes that decisions are made by a diffusion process driven by a neurally plausible, shunting VSTM. The VSTM trace encodes the transient outputs of early visual filters in a durable form that is preserved for the time needed to make a decision. Attention increases the efficiency of VSTM encoding, either by increasing the rate of trace formation or by reducing the delay before trace formation begins. The theory provides a detailed, quantitative account of attentional effects in spatial cuing tasks at the level of response accuracy and the response time distributions. (c) 2009 APA, all rights reserved

Efficient ConvNet Feature Extraction with Multiple RoI Pooling for Landmark-Based Visual Localization of Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Yi Hou

2017-01-01

Full Text Available Efficient and robust visual localization is important for autonomous vehicles. By achieving impressive localization accuracy under conditions of significant changes, ConvNet landmark-based approach has attracted the attention of people in several research communities including autonomous vehicles. Such an approach relies heavily on the outstanding discrimination power of ConvNet features to match detected landmarks between images. However, a major challenge of this approach is how to extract discriminative ConvNet features efficiently. To address this challenging, inspired by the high efficiency of the region of interest (RoI pooling layer, we propose a Multiple RoI (MRoI pooling technique, an enhancement of RoI, and a simple yet efficient ConvNet feature extraction method. Our idea is to leverage MRoI pooling to exploit multilevel and multiresolution information from multiple convolutional layers and then fuse them to improve the discrimination capacity of the final ConvNet features. The main advantages of our method are (a high computational efficiency for real-time applications; (b GPU memory efficiency for mobile applications; and (c use of pretrained model without fine-tuning or retraining for easy implementation. Experimental results on four datasets have demonstrated not only the above advantages but also the high discriminating power of the extracted ConvNet features with state-of-the-art localization accuracy.

Enhanced visual performance in obsessive compulsive personality disorder.

Science.gov (United States)

Ansari, Zohreh; Fadardi, Javad Salehi

2016-12-01

Visual performance is considered as commanding modality in human perception. We tested whether Obsessive-compulsive personality disorder (OCPD) people do differently in visual performance tasks than people without OCPD. One hundred ten students of Ferdowsi University of Mashhad and non-student participants were tested by Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II), among whom 18 (mean age = 29.55; SD = 5.26; 84% female) met the criteria for OCPD classification; controls were 20 persons (mean age = 27.85; SD = 5.26; female = 84%), who did not met the OCPD criteria. Both groups were tested on a modified Flicker task for two dimensions of visual performance (i.e., visual acuity: detecting the location of change, complexity, and size; and visual contrast sensitivity). The OCPD group had responded more accurately on pairs related to size, complexity, and contrast, but spent more time to detect a change on pairs related to complexity and contrast. The OCPD individuals seem to have more accurate visual performance than non-OCPD controls. The findings support the relationship between personality characteristics and visual performance within the framework of top-down processing model. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Relationship between the supramolecular structure and the transfection efficiency for cationic micelle/DNA complexes

International Nuclear Information System (INIS)

Sakuragi, Mina; Kusuki, Shota; Hamada, Emi; Sakurai, Kazuo; Masunaga, Hiroyasu; Sasaki, Sono

2009-01-01

We synthesized a cationic lipid benzyl amine derivative bearing a primary amine as the head group and evaluated its transfection efficiency as a DNA carrier. A lipoplex (complex of DNA and lipid micelle) was prepared by mixing BA and two neutral colipids (DOPE and DLPC). When we compared the transfection efficiency at various compositions, we found that B-lipoplex (BA/DOPE/DLPC=1/2/1) was the most efficient while A-lipoplex (BA/DLPC=1/1) showed no transfection. We compared A-lipoplex with B-lipoplex by use of SAXS, fluorescence spectrum of ethidium bromide and pyrene. These results indicated that A-lipoplex formed a lamellar or cylinder structure within which DNA molecules were trapped in the lipid alkyl chain, while B-lipoplex formed cylinders where DNAs were intercalated between the lipid micelle cylinders. (author)

Efficient light-harvesting using non-carbonyl carotenoids: Energy transfer dynamics in the VCP complex from Nannochloropsis oceanica.

Science.gov (United States)

Keşan, Gürkan; Litvín, Radek; Bína, David; Durchan, Milan; Šlouf, Václav; Polívka, Tomáš

2016-04-01

Violaxanthin-chlorophyll a protein (VCP) from Nannochloropsis oceanica is a Chl a-only member of the LHC family of light-harvesting proteins. VCP binds carotenoids violaxanthin (Vio), vaucheriaxanthin (Vau), and vaucheriaxanthin-ester (Vau-ester). Here we report on energy transfer pathways in the VCP complex. The overall carotenoid-to-Chla energy transfer has efficiency over 90%. Based on their energy transfer properties, the carotenoids in VCP can be divided into two groups; blue carotenoids with the lowest energy absorption band around 480nm and red carotenoids with absorption extended up to 530nm. Both carotenoid groups transfer energy efficiently from their S2 states, reaching efficiencies of ~70% (blue) and ~60% (red). The S1 pathway, however, is efficient only for the red carotenoid pool for which two S1 routes characterized by 0.33 and 2.4ps time constants were identified. For the blue carotenoids the S1-mediated pathway is represented only by a minor route likely involving a hot S1 state. The relaxed S1 state of blue carotenoids decays to the ground state within 21ps. Presence of a fraction of non-transferring red carotenoids with the S1 lifetime of 13ps indicates some specific carotenoid-protein interaction that must shorten the intrinsic S1 lifetime of Vio and/or Vau whose S1 lifetimes in methanol are 26 and 29ps, respectively. The VCP complex from N. oceanica is the first example of a light-harvesting complex binding only non-carbonyl carotenoids with carotenoid-to-chlorophyll energy transfer efficiency over 90%. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel stable 3D luminescent uranyl complex for highly efficient and sensitive recognition of Ru3+ and biomolecules

Science.gov (United States)

Tian, Hong-Hong; Chen, Liang-Ting; Zhang, Rong-Lan; Zhao, Jian-She; Liu, Chi-Yang; Weng, Ng Seik

2018-02-01

A novel highly stable 3D luminescent uranyl coordination polymer, namely {[UO2(L)]·DMA}n (1), was assembled with uranyl salt and a glycine-derivative ligand [6-(carboxymethyl-amino)-4-oxo-4,5-dihydro-[1,3,5]triazin-2-ylamino]-acetic acid (H2L) under solvothermal reaction. Besides, It was found that complex 1 possesses excellent luminescent properties, particularly the efficient selectivity and sensitivity in the recognition of Ru3+, biomacromolecule bovine serum albumin (BSA), biological small molecules dopamine (DA), ascorbic acid (AA) and uric acid (UA) in the water solution based on a "turn-off" mechanism. Accordingly, the luminescent explorations also demonstrated that complex 1 could be acted as an efficient luminescent probe with high quenching efficiency and low detection limit for selectively detecting Ru3+ and biomolecules (DA, AA, UA and BSA). It was noted that the framework structure of complex 1 still remains highly stable after quenching, which was verified by powder X-ray diffraction (PXRD).

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

Science.gov (United States)

Schiltz, Holly Kristine

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

Non-toxic lead sulfide nanodots as efficient contrast agents for visualizing gastrointestinal tract.

Science.gov (United States)

Liu, Zhen; Ran, Xiang; Liu, Jianhua; Du, Yingda; Ren, Jinsong; Qu, Xiaogang

2016-09-01

Non-invasive imaging of gastrointestinal (GI) tract using novel but efficient contrast agents is of the most important issues in the diagnosis and prognosis of GI diseases. Here, for the first time, we reported the design and synthesis of biothiol-decorated lead sulfide nanodots, as well as their usages in functional dual-modality imaging of GI tract in vivo. Due to the presence of glutathione on the surface of the nanodots, these well-prepared contrast agents could decrease the unwanted ion leakage, withstand the harsh conditions in GI tract, and avoid the systemic absorption after oral administration. Compared with clinical barium meal and iodine-based contrast agents, these nanodots exhibited much more significant enhancement in contrast efficiency during both 2D X-ray imaging and 3D CT imaging. Different from some conventional invasive imaging modalities, such as gastroscope and enteroscope, non-invasive imaging strategy by using glutathione modified PbS nanodots as contrast agents could reduce the painfulness towards patients, facilitate the imaging procedure, and economize the manipulation period. Moreover, long-term toxicity and bio-distribution of these nanodots after oral administration were evaluated in detail, which indicated their overall safety. Based on our present study, these nanodots could act as admirable contrast agents to integrate X-ray imaging and CT imaging for the direct visualization of GI tract. Copyright © 2016 Elsevier Ltd. All rights reserved.

Efficient growth of complex graph states via imperfect path erasure

International Nuclear Information System (INIS)

Campbell, Earl T; Fitzsimons, Joseph; Benjamin, Simon C; Kok, Pieter

2007-01-01

Given a suitably large and well connected (complex) graph state, any quantum algorithm can be implemented purely through local measurements on the individual qubits. Measurements can also be used to create the graph state: path erasure techniques allow one to entangle multiple qubits by determining only global properties of the qubits. Here, this powerful approach is extended by demonstrating that even imperfect path erasure can produce the required graph states with high efficiency. By characterizing the degree of error in each path erasure attempt, one can subsume the resulting imperfect entanglement into an extended graph state formalism. The subsequent growth of the improper graph state can be guided, through a series of strategic decisions, in such a way as to bound the growth of the error and eventually yield a high-fidelity graph state. As an implementation of these techniques, we develop an analytic model for atom (or atom-like) qubits in mismatched cavities, under the double-heralding entanglement procedure of Barrett and Kok (2005 Phys. Rev. A 71 060310). Compared to straightforward post-selection techniques our protocol offers a dramatic improvement in growing complex high-fidelity graph states

Effect of task complexity on intelligence and neural efficiency in children: an event-related potential study.

Science.gov (United States)

Zhang, Qiong; Shi, Jiannong; Luo, Yuejia; Liu, Sainan; Yang, Jie; Shen, Mowei

2007-10-08

The present study investigates the effects of task complexity, intelligence and neural efficiency on children's performance on an Elementary Cognitive Task. Twenty-three children were divided into two groups on the basis of their Raven Progressive Matrix scores and were then asked to complete a choice reaction task with two test conditions. We recorded the electroencephalogram and calculated the peak latencies and amplitudes for anteriorly distributed P225, N380 and late positive component. Our results suggested shorter late positive component latencies in brighter children, possibly reflecting a higher processing speed in these individuals. Increased P225 amplitude and increased N380 amplitudes for brighter children may indicate a more efficient allocation of attention for brighter children. No moderating effect of task complexity on brain-intelligence relationship was found.

Complex networks-based energy-efficient evolution model for wireless sensor networks

Energy Technology Data Exchange (ETDEWEB)

Zhu Hailin [Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia, Beijing University of Posts and Telecommunications, P.O. Box 106, Beijing 100876 (China)], E-mail: zhuhailin19@gmail.com; Luo Hong [Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia, Beijing University of Posts and Telecommunications, P.O. Box 106, Beijing 100876 (China); Peng Haipeng; Li Lixiang; Luo Qun [Information Secure Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China)

2009-08-30

Based on complex networks theory, we present two self-organized energy-efficient models for wireless sensor networks in this paper. The first model constructs the wireless sensor networks according to the connectivity and remaining energy of each sensor node, thus it can produce scale-free networks which have a performance of random error tolerance. In the second model, we not only consider the remaining energy, but also introduce the constraint of links to each node. This model can make the energy consumption of the whole network more balanced. Finally, we present the numerical experiments of the two models.

Complex networks-based energy-efficient evolution model for wireless sensor networks

International Nuclear Information System (INIS)

Zhu Hailin; Luo Hong; Peng Haipeng; Li Lixiang; Luo Qun

2009-01-01

Based on complex networks theory, we present two self-organized energy-efficient models for wireless sensor networks in this paper. The first model constructs the wireless sensor networks according to the connectivity and remaining energy of each sensor node, thus it can produce scale-free networks which have a performance of random error tolerance. In the second model, we not only consider the remaining energy, but also introduce the constraint of links to each node. This model can make the energy consumption of the whole network more balanced. Finally, we present the numerical experiments of the two models.

Storytelling and Visualization: An Extended Survey

OpenAIRE

Chao Tong; Richard Roberts; Rita Borgo; Sean Walton; Robert S. Laramee; Kodzo Wegba; Aidong Lu; Yun Wang; Huamin Qu; Qiong Luo; Xiaojuan Ma

2018-01-01

Throughout history, storytelling has been an effective way of conveying information and knowledge. In the field of visualization, storytelling is rapidly gaining momentum and evolving cutting-edge techniques that enhance understanding. Many communities have commented on the importance of storytelling in data visualization. Storytellers tend to be integrating complex visualizations into their narratives in growing numbers. In this paper, we present a survey of storytelling literature in visual...

Efficient reconfigurable hardware architecture for accurately computing success probability and data complexity of linear attacks

DEFF Research Database (Denmark)

Bogdanov, Andrey; Kavun, Elif Bilge; Tischhauser, Elmar

2012-01-01

An accurate estimation of the success probability and data complexity of linear cryptanalysis is a fundamental question in symmetric cryptography. In this paper, we propose an efficient reconfigurable hardware architecture to compute the success probability and data complexity of Matsui's Algorithm...... block lengths ensures that any empirical observations are not due to differences in statistical behavior for artificially small block lengths. Rather surprisingly, we observed in previous experiments a significant deviation between the theory and practice for Matsui's Algorithm 2 for larger block sizes...

Research on Visual Servo Grasping of Household Objects for Nonholonomic Mobile Manipulator

Directory of Open Access Journals (Sweden)

Huangsheng Xie

2014-01-01

Full Text Available This paper focuses on the problem of visual servo grasping of household objects for nonholonomic mobile manipulator. Firstly, a new kind of artificial object mark based on QR (Quick Response Code is designed, which can be affixed to the surface of household objects. Secondly, after summarizing the vision-based autonomous mobile manipulation system as a generalized manipulator, the generalized manipulator’s kinematic model is established, the analytical inverse kinematic solutions of the generalized manipulator are acquired, and a novel active vision based camera calibration method is proposed to determine the hand-eye relationship. Finally, a visual servo switching control law is designed to control the service robot to finish object grasping operation. Experimental results show that QR Code-based artificial object mark can overcome the difficulties brought by household objects’ variety and operation complexity, and the proposed visual servo scheme makes it possible for service robot to grasp and deliver objects efficiently.

Visual search of Mooney faces

Directory of Open Access Journals (Sweden)

Jessica Emeline Goold

2016-02-01

Full Text Available Faces spontaneously capture attention. However, which special attributes of a face underlie this effect are unclear. To address this question, we investigate how gist information, specific visual properties and differing amounts of experience with faces affect the time required to detect a face. Three visual search experiments were conducted investigating the rapidness of human observers to detect Mooney face images. Mooney images are two-toned, ambiguous images. They were used in order to have stimuli that maintain gist information but limit low-level image properties. Results from the experiments show: 1 although upright Mooney faces were searched inefficiently, they were detected more rapidly than inverted Mooney face targets, demonstrating the important role of gist information in guiding attention towards a face. 2 Several specific Mooney face identities were searched efficiently while others were not, suggesting the involvement of specific visual properties in face detection. 3 By providing participants with unambiguous gray-scale versions of the Mooney face targets prior to the visual search task, the targets were detected significantly more efficiently, suggesting that prior experience with Mooney faces improves the ability to extract gist information for rapid face detection. However, a week of training with Mooney face categorization did not lead to even more efficient visual search of Mooney face targets. In summary, these results reveal that specific local image properties cannot account for how faces capture attention. On the other hand, gist information alone cannot account for how faces capture attention either. Prior experience facilitates the effect of gist on visual search of faces, making faces a special object category for guiding attention.

Modulation of the Singlet Oxygen Generation from the Double Strand DNA-SYBR Green I Complex Mediated by T-Melamine-T Mismatch for Visual Detection of Melamine.

Science.gov (United States)

Hu, Hao; Zhang, Jinyi; Ding, Yu; Zhang, Xinfeng; Xu, Kailai; Hou, Xiandeng; Wu, Peng

2017-05-02

Singlet oxygen ( 1 O 2 ), generated via photosensitization, has been proved to oxidize chromogenic substrates with neither H 2 O 2 oxidation nor enzyme (horseradish peroxidase, HRP) catalysis. Of the various methods for modulation of the 1 O 2 generation, DNA-controlled photosensitization received great attention. Therefore, integration of the formation/deformation DNA structures with DNA-controlled photosensitization will be extremely appealing in visual biosensor developments. Here, the stable melamine-thymine complex was explored in combination with DNA-controlled photosensitization for visual detection of melamine. A T-rich single stand DNA was utilized as the recognition unit. Upon the formation of the T-M-T complex, double stand DNA was formed, which was ready for the binding of SYBR Green I and activated the photosensitization. Subsequent oxidation of TMB allowed visual detection of melamine in dairy products, with spike-recoveries ranging from 94% to 106%.

Training complexity is not decisive factor for improving adaptation to visual sensory conflict.

Science.gov (United States)

Yang, Yang; Pu, Fang; Li, Shuyu; Li, Yan; Li, Deyu; Fan, Yubo

2012-01-01

Ground-based preflight training utilizing unusual visual stimuli is useful for decreasing the susceptibility to space motion sickness (SMS). The effectiveness of the sensorimotor adaptation training is affected by the training tasks, but what kind of task is more effective remains unknown. Whether the complexity is the decisive factor to consider for designing the training and if other factors are more important need to be analyzed. The results from the analysis can help to optimize the preflight training tasks for astronauts. Twenty right-handed subjects were asked to draw the right path of 45° rotated maze before and after 30 min training. Subjects wore an up-down reversing prism spectacle in test and training sessions. Two training tasks were performed: drawing the right path of the horizontal maze (complex task but with different orientation feature) and drawing the L-shape lines (easy task with same orientation feature). The error rate and the executing time were measured during the test. Paired samples t test was used to compare the effects of the two training tasks. After each training, the error rate and the executing time were significantly decreased. However, the training effectiveness of the easy task was better as the test was finished more quickly and accurately. The complexity is not always the decisive factor for designing the adaptation training task, e.g. the orientation feature is more important in this study. In order to accelerate the adaptation and to counter SMS, the task for astronauts preflight adaptation training could be simple activities with the key features.

Designing Data Visualizations Representing Informational Relationships

CERN Document Server

Steele, Julie

2011-01-01

Data visualization is an efficient and effective medium for communicating large amounts of information, but the design process can often seem like an unexplainable creative endeavor. This concise book aims to demystify the design process by showing you how to use a linear decision-making process to encode your information visually. Delve into different kinds of visualization, including infographics and visual art, and explore the influences at work in each one. Then learn how to apply these concepts to your design process. Learn data visualization classifications, including explanatory, expl

Selection of bi-level image compression method for reduction of communication energy in wireless visual sensor networks

Science.gov (United States)

Khursheed, Khursheed; Imran, Muhammad; Ahmad, Naeem; O'Nils, Mattias

2012-06-01

Wireless Visual Sensor Network (WVSN) is an emerging field which combines image sensor, on board computation unit, communication component and energy source. Compared to the traditional wireless sensor network, which operates on one dimensional data, such as temperature, pressure values etc., WVSN operates on two dimensional data (images) which requires higher processing power and communication bandwidth. Normally, WVSNs are deployed in areas where installation of wired solutions is not feasible. The energy budget in these networks is limited to the batteries, because of the wireless nature of the application. Due to the limited availability of energy, the processing at Visual Sensor Nodes (VSN) and communication from VSN to server should consume as low energy as possible. Transmission of raw images wirelessly consumes a lot of energy and requires higher communication bandwidth. Data compression methods reduce data efficiently and hence will be effective in reducing communication cost in WVSN. In this paper, we have compared the compression efficiency and complexity of six well known bi-level image compression methods. The focus is to determine the compression algorithms which can efficiently compress bi-level images and their computational complexity is suitable for computational platform used in WVSNs. These results can be used as a road map for selection of compression methods for different sets of constraints in WVSN.

Seeing More by Showing Less: Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization.

Directory of Open Access Journals (Sweden)

Chantal M W Tax

Full Text Available Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI approaches that can also model "crossing fibers", the complexity of the fiber network as reconstructed with tractography has increased tremendously. Many pathways interdigitate and overlap, which hampers an unequivocal 3D visualization of the network and impedes an efficient study of its organization. We propose a novel fiber tractography visualization approach that interactively and selectively adapts the transparency rendering of fiber trajectories as a function of their orientation to enhance the visibility of the spatial context. More specifically, pathways that are oriented (locally or globally along a user-specified opacity axis can be made more transparent or opaque. This substantially improves the 3D visualization of the fiber network and the exploration of tissue configurations that would otherwise be largely covered by other pathways. We present examples of fiber bundle extraction and neurosurgical planning cases where the added benefit of our new visualization scheme is demonstrated over conventional fiber visualization approaches.

Functional size of human visual area V1: a neural correlate of top-down attention.

Science.gov (United States)

Verghese, Ashika; Kolbe, Scott C; Anderson, Andrew J; Egan, Gary F; Vidyasagar, Trichur R

2014-06-01

Heavy demands are placed on the brain's attentional capacity when selecting a target item in a cluttered visual scene, or when reading. It is widely accepted that such attentional selection is mediated by top-down signals from higher cortical areas to early visual areas such as the primary visual cortex (V1). Further, it has also been reported that there is considerable variation in the surface area of V1. This variation may impact on either the number or specificity of attentional feedback signals and, thereby, the efficiency of attentional mechanisms. In this study, we investigated whether individual differences between humans performing attention-demanding tasks can be related to the functional area of V1. We found that those with a larger representation in V1 of the central 12° of the visual field as measured using BOLD signals from fMRI were able to perform a serial search task at a faster rate. In line with recent suggestions of the vital role of visuo-spatial attention in reading, the speed of reading showed a strong positive correlation with the speed of visual search, although it showed little correlation with the size of V1. The results support the idea that the functional size of the primary visual cortex is an important determinant of the efficiency of selective spatial attention for simple tasks, and that the attentional processing required for complex tasks like reading are to a large extent determined by other brain areas and inter-areal connections. Copyright © 2014 Elsevier Inc. All rights reserved.

Contingency Analysis Post-Processing With Advanced Computing and Visualization

Energy Technology Data Exchange (ETDEWEB)

Chen, Yousu; Glaesemann, Kurt; Fitzhenry, Erin

2017-07-01

Contingency analysis is a critical function widely used in energy management systems to assess the impact of power system component failures. Its outputs are important for power system operation for improved situational awareness, power system planning studies, and power market operations. With the increased complexity of power system modeling and simulation caused by increased energy production and demand, the penetration of renewable energy and fast deployment of smart grid devices, and the trend of operating grids closer to their capacity for better efficiency, more and more contingencies must be executed and analyzed quickly in order to ensure grid reliability and accuracy for the power market. Currently, many researchers have proposed different techniques to accelerate the computational speed of contingency analysis, but not much work has been published on how to post-process the large amount of contingency outputs quickly. This paper proposes a parallel post-processing function that can analyze contingency analysis outputs faster and display them in a web-based visualization tool to help power engineers improve their work efficiency by fast information digestion. Case studies using an ESCA-60 bus system and a WECC planning system are presented to demonstrate the functionality of the parallel post-processing technique and the web-based visualization tool.

Immunogenetic Management Software: a new tool for visualization and analysis of complex immunogenetic datasets.

Science.gov (United States)

Johnson, Z P; Eady, R D; Ahmad, S F; Agravat, S; Morris, T; Else, J; Lank, S M; Wiseman, R W; O'Connor, D H; Penedo, M C T; Larsen, C P; Kean, L S

2012-04-01

Here we describe the Immunogenetic Management Software (IMS) system, a novel web-based application that permits multiplexed analysis of complex immunogenetic traits that are necessary for the accurate planning and execution of experiments involving large animal models, including nonhuman primates. IMS is capable of housing complex pedigree relationships, microsatellite-based MHC typing data, as well as MHC pyrosequencing expression analysis of class I alleles. It includes a novel, automated MHC haplotype naming algorithm and has accomplished an innovative visualization protocol that allows users to view multiple familial and MHC haplotype relationships through a single, interactive graphical interface. Detailed DNA and RNA-based data can also be queried and analyzed in a highly accessible fashion, and flexible search capabilities allow experimental choices to be made based on multiple, individualized and expandable immunogenetic factors. This web application is implemented in Java, MySQL, Tomcat, and Apache, with supported browsers including Internet Explorer and Firefox on Windows and Safari on Mac OS. The software is freely available for distribution to noncommercial users by contacting Leslie.kean@emory.edu. A demonstration site for the software is available at http://typing.emory.edu/typing_demo , user name: imsdemo7@gmail.com and password: imsdemo.

Social negative bootstrapping for visual categorization

NARCIS (Netherlands)

Li, X.; Snoek, C.G.M.; Worring, M.; Smeulders, A.W.M.

2011-01-01

To learn classifiers for many visual categories, obtaining labeled training examples in an efficient way is crucial. Since a classifier tends to misclassify negative examples which are visually similar to positive examples, inclusion of such informative negatives should be stressed in the learning

Improved efficiency of organic light-emitting diodes based on a europium complex by fluorescent dye

Energy Technology Data Exchange (ETDEWEB)

You Han [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Fang Junfeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Gao Jia [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Ma Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China)]. E-mail: mdg1014@ciac.jl.cn

2007-01-15

Improved efficiency of organic light-emitting diodes (OLEDs) based on europium complexes have been realized by using a fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6 (1,1,7,7-tetramethyljulolidyl-9-enyl))-4H-pyran (DCJTB) doping .The luminous efficiency of the devices with a fluorescent dye in the emissive layer was found to improve two times of that in devices without fluorescent dye. The devices showed pure red light, which is the characteristic emission of trivalent europium ion with a full-width at half-maximum of 3 nm.The maximum brightness and luminous efficiency reached 1200 cd/m{sup 2} at 23 V and 7.3 cd/A (2.0 lm/w), respectively, at a current density of 0.35 mA/cm{sup 2}.

Visual attention mitigates information loss in small- and large-scale neural codes.

Science.gov (United States)

Sprague, Thomas C; Saproo, Sameer; Serences, John T

2015-04-01

The visual system transforms complex inputs into robust and parsimonious neural codes that efficiently guide behavior. Because neural communication is stochastic, the amount of encoded visual information necessarily decreases with each synapse. This constraint requires that sensory signals are processed in a manner that protects information about relevant stimuli from degradation. Such selective processing--or selective attention--is implemented via several mechanisms, including neural gain and changes in tuning properties. However, examining each of these effects in isolation obscures their joint impact on the fidelity of stimulus feature representations by large-scale population codes. Instead, large-scale activity patterns can be used to reconstruct representations of relevant and irrelevant stimuli, thereby providing a holistic understanding about how neuron-level modulations collectively impact stimulus encoding. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficient catalytic cycloalkane oxidation employing a "helmet" phthalocyaninato iron(III) complex.

Science.gov (United States)

Brown, Elizabeth S; Robinson, Jerome R; McCoy, Aaron M; McGaff, Robert W

2011-06-14

We have examined the catalytic activity of an iron(III) complex bearing the 14,28-[1,3-diiminoisoindolinato]phthalocyaninato (diiPc) ligand in oxidation reactions with three substrates (cyclohexane, cyclooctane, and indan). This modified metallophthalocyaninato complex serves as an efficient and selective catalyst for the oxidation of cyclohexane and cyclooctane, and to a far lesser extent indan. In the oxidations of cyclohexane and cyclooctane, in which hydrogen peroxide is employed as the oxidant under inert atmosphere, we have observed turnover numbers of 100.9 and 122.2 for cyclohexanol and cyclooctanol, respectively. The catalyst shows strong selectivity for alcohol (vs. ketone) formation, with alcohol to ketone (A/K) ratios of 6.7 and 21.0 for the cyclohexane and cyclooctane oxidations, respectively. Overall yields (alcohol + ketone) were 73% for cyclohexane and 92% for cyclooctane, based upon the total hydrogen peroxide added. In the catalytic oxidation of indan under similar conditions, the TON for 1-indanol was 10.1, with a yield of 12% based upon hydrogen peroxide. No 1-indanone was observed in the product mixture.

Enhanced Massive Visualization of Engines Performance

International Nuclear Information System (INIS)

Rostand, N D; Eglantine, H; Jerôme, L

2012-01-01

Today, we are witnessing an increasing complexity of transport in order to deal with requirements of safety, security, reliability and efficiency. Such transport is generally equipped with drive systems; it is nevertheless for engine manufacturers to overcome the performance requirements of energy efficiency throughout their operations. To this end, this article proposes a performance monitoring solution for a large fleet of engines in operation. It uses a pre-calibrated physical model developed by the engine manufacturer regarding the performance objectives as reference. The physical model is firstly decomposed into critical performance modules, and is secondly updated on current observations extracted at specific predefined operating conditions in order to derive residual errors status of each engine tested. Through a process of standardization of those contextual differences remaining, the solution offers a synthesis mapping to visualize the evolution of performance of each engine throughout its operations. This article describes the theoretical methodology of implementation mainly based on universal mathematical foundations, and vindicates the interests of its industrialization in the light of the proactive findings.

Automatic User Interface Generation for Visualizing Big Geoscience Data

Science.gov (United States)

Yu, H.; Wu, J.; Zhou, Y.; Tang, Z.; Kuo, K. S.

2016-12-01

Along with advanced computing and observation technologies, geoscience and its related fields have been generating a large amount of data at an unprecedented growth rate. Visualization becomes an increasingly attractive and feasible means for researchers to effectively and efficiently access and explore data to gain new understandings and discoveries. However, visualization has been challenging due to a lack of effective data models and visual representations to tackle the heterogeneity of geoscience data. We propose a new geoscience data visualization framework by leveraging the interface automata theory to automatically generate user interface (UI). Our study has the following three main contributions. First, geoscience data has its unique hierarchy data structure and complex formats, and therefore it is relatively easy for users to get lost or confused during their exploration of the data. By applying interface automata model to the UI design, users can be clearly guided to find the exact visualization and analysis that they want. In addition, from a development perspective, interface automaton is also easier to understand than conditional statements, which can simplify the development process. Second, it is common that geoscience data has discontinuity in its hierarchy structure. The application of interface automata can prevent users from suffering automation surprises, and enhance user experience. Third, for supporting a variety of different data visualization and analysis, our design with interface automata could also make applications become extendable in that a new visualization function or a new data group could be easily added to an existing application, which reduces the overhead of maintenance significantly. We demonstrate the effectiveness of our framework using real-world applications.

Efficient Simulation Modeling of an Integrated High-Level-Waste Processing Complex

International Nuclear Information System (INIS)

Gregory, Michael V.; Paul, Pran K.

2000-01-01

An integrated computational tool named the Production Planning Model (ProdMod) has been developed to simulate the operation of the entire high-level-waste complex (HLW) at the Savannah River Site (SRS) over its full life cycle. ProdMod is used to guide SRS management in operating the waste complex in an economically efficient and environmentally sound manner. SRS HLW operations are modeled using coupled algebraic equations. The dynamic nature of plant processes is modeled in the form of a linear construct in which the time dependence is implicit. Batch processes are modeled in discrete event-space, while continuous processes are modeled in time-space. The ProdMod methodology maps between event-space and time-space such that the inherent mathematical discontinuities in batch process simulation are avoided without sacrificing any of the necessary detail in the batch recipe steps. Modeling the processes separately in event- and time-space using linear constructs, and then coupling the two spaces, has accelerated the speed of simulation compared to a typical dynamic simulation. The ProdMod simulator models have been validated against operating data and other computer codes. Case studies have demonstrated the usefulness of the ProdMod simulator in developing strategies that demonstrate significant cost savings in operating the SRS HLW complex and in verifying the feasibility of newly proposed processes

Visual Guided Navigation

National Research Council Canada - National Science Library

Banks, Martin

1999-01-01

.... Similarly, the problem of visual navigation is the recovery of an observer's self-motion with respect to the environment from the moving pattern of light reaching the eyes and the complex of extra...

Using Visual Analytics to Maintain Situation Awareness in Astrophysics

Energy Technology Data Exchange (ETDEWEB)

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.

Designing and visualizing the water-energy-food nexus system

Science.gov (United States)

Endo, A.; Kumazawa, T.; Yamada, M.; Kato, T.

2017-12-01

The objective of this study is to design and visualize a water-energy-food nexus system to identify the interrelationships between water-energy-food (WEF) resources and to understand the subsequent complexity of WEF nexus systems holistically, taking an interdisciplinary approach. Object-oriented concepts and ontology engineering methods were applied according to the hypothesis that the chains of changes in linkages between water, energy, and food resources holistically affect the water-energy-food nexus system, including natural and social systems, both temporally and spatially. The water-energy-food nexus system that is developed is significant because it allows us to: 1) visualize linkages between water, energy, and food resources in social and natural systems; 2) identify tradeoffs between these resources; 3) find a way of using resources efficiently or enhancing the synergy between the utilization of different resources; and 4) aid scenario planning using economic tools. The paper also discusses future challenges for applying the developed water-energy-food nexus system in other areas.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-03-01

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

Efficient human face detection in infancy.

Science.gov (United States)

Jakobsen, Krisztina V; Umstead, Lindsey; Simpson, Elizabeth A

2016-01-01

Adults detect conspecific faces more efficiently than heterospecific faces; however, the development of this own-species bias (OSB) remains unexplored. We tested whether 6- and 11-month-olds exhibit OSB in their attention to human and animal faces in complex visual displays with high perceptual load (25 images competing for attention). Infants (n = 48) and adults (n = 43) passively viewed arrays containing a face among 24 non-face distractors while we measured their gaze with remote eye tracking. While OSB is typically not observed until about 9 months, we found that, already by 6 months, human faces were more likely to be detected, were detected more quickly (attention capture), and received longer looks (attention holding) than animal faces. These data suggest that 6-month-olds already exhibit OSB in face detection efficiency, consistent with perceptual attunement. This specialization may reflect the biological importance of detecting conspecific faces, a foundational ability for early social interactions. © 2015 Wiley Periodicals, Inc.

Investigating long-range correlation properties in EEG during complex cognitive tasks

International Nuclear Information System (INIS)

Karkare, Siddharth; Saha, Goutam; Bhattacharya, Joydeep

2009-01-01

Previous work shows the presence of scale invariance and long-range correlations in ongoing and spontaneous activity of large scale brain responses (i.e. EEG), and such scaling behavior can also be modulated by simple sensory stimulus. However, little is known whether such alteration but not destruction in scaling properties also occurs during complex cognitive processing and if neuroplasticity plays any role in mediating such changes. In this study, we addressed these issues by investigating scaling properties of multivariate EEG signals obtained from two broad groups - artists and non-artists - while they performed complex tasks of perception and mental imagery of visual art objects. We found that brain regions showing increased correlation properties from rest were similar for both tasks, suggesting that brain networks responsible for visual perception are reactivated for mental imagery. Further, we observed that the two groups could be differentiated by scaling exponents and an artificial neural network based classifier achieved a classification efficiency of over 80%. These results altogether suggest that specific complex cognitive task demands and task-specific expertise can modify the temporal scale-free dynamics of brain responses.

Investigating long-range correlation properties in EEG during complex cognitive tasks

Energy Technology Data Exchange (ETDEWEB)

Karkare, Siddharth [Department of Electrical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Saha, Goutam [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhattacharya, Joydeep [Department of Psychology, Goldsmiths College, University of London, New Cross, London SE14 6NW (United Kingdom); Commission for Scientific Visualization, Austrian Academy of Sciences, Vienna A1220 (Austria)], E-mail: j.bhattacharya@gold.ac.uk

2009-11-30

Previous work shows the presence of scale invariance and long-range correlations in ongoing and spontaneous activity of large scale brain responses (i.e. EEG), and such scaling behavior can also be modulated by simple sensory stimulus. However, little is known whether such alteration but not destruction in scaling properties also occurs during complex cognitive processing and if neuroplasticity plays any role in mediating such changes. In this study, we addressed these issues by investigating scaling properties of multivariate EEG signals obtained from two broad groups - artists and non-artists - while they performed complex tasks of perception and mental imagery of visual art objects. We found that brain regions showing increased correlation properties from rest were similar for both tasks, suggesting that brain networks responsible for visual perception are reactivated for mental imagery. Further, we observed that the two groups could be differentiated by scaling exponents and an artificial neural network based classifier achieved a classification efficiency of over 80%. These results altogether suggest that specific complex cognitive task demands and task-specific expertise can modify the temporal scale-free dynamics of brain responses.

Psycho acoustical Measures in Individuals with Congenital Visual Impairment.

Science.gov (United States)

Kumar, Kaushlendra; Thomas, Teenu; Bhat, Jayashree S; Ranjan, Rajesh

2017-12-01

In congenital visual impaired individuals one modality is impaired (visual modality) this impairment is compensated by other sensory modalities. There is evidence that visual impaired performed better in different auditory task like localization, auditory memory, verbal memory, auditory attention, and other behavioural tasks when compare to normal sighted individuals. The current study was aimed to compare the temporal resolution, frequency resolution and speech perception in noise ability in individuals with congenital visual impaired and normal sighted. Temporal resolution, frequency resolution, and speech perception in noise were measured using MDT, GDT, DDT, SRDT, and SNR50 respectively. Twelve congenital visual impaired participants with age range of 18 to 40 years were taken and equal in number with normal sighted participants. All the participants had normal hearing sensitivity with normal middle ear functioning. Individual with visual impairment showed superior threshold in MDT, SRDT and SNR50 as compared to normal sighted individuals. This may be due to complexity of the tasks; MDT, SRDT and SNR50 are complex tasks than GDT and DDT. Visual impairment showed superior performance in auditory processing and speech perception with complex auditory perceptual tasks.

Familiarity Enhances Visual Working Memory for Faces

Science.gov (United States)

Jackson, Margaret C.; Raymond, Jane E.

2008-01-01

Although it is intuitive that familiarity with complex visual objects should aid their preservation in visual working memory (WM), empirical evidence for this is lacking. This study used a conventional change-detection procedure to assess visual WM for unfamiliar and famous faces in healthy adults. Across experiments, faces were upright or…

Organizational and visual memory deficits in schizophrenia and bipolar psychoses using the Rey-Osterrieth complex figure: effects of duration of illness.

Science.gov (United States)

Seidman, Larry J; Lanca, Margaret; Kremen, William S; Faraone, Stephen V; Tsuang, Ming T

2003-10-01

Verbal declarative memory deficits in schizophrenia are well documented whereas visual declarative memory is less studied. Moreover, there are limited data on whether organizational and visual memory deficits are specific to schizophrenic psychoses. We compared visual memory and organizational function in patients with chronic schizophrenia (n=79) and chronic bipolar psychotic disorder (n=14), and in healthy controls (n=84) using the Rey-Osterrieth Complex Figure (ROCF), testing whether organizational impairments (i.e., executive dysfunctions) account for the visual memory deficit. Groups were comparable on age, handedness and expected intellectual ability (based on single word reading). Using analyses of covariance with sex, parental SES and ethnicity as co-variates, patients with schizophrenia were significantly more impaired than controls on copy accuracy, on recall accuracy, and on percent accuracy of recall. Patients with schizophrenia used a more detail-oriented style on copy and recall and had significantly worse recognition memory. After co-varying IQ, copy organization was also significantly different between the groups. Results for accuracy of copy and recall were not significantly attenuated when controlling for copy organization. Duration of illness was associated with visual memory. Bipolar patients performed at an intermediate level between controls and patients with schizophrenia. The data suggest that in schizophrenia, patients have a visual memory disorder characterized by both organizational processing impairments and retention difficulties, and that there is a decline in visual memory functions with duration of illness. Further research is required to determine whether similar mechanisms underlie the neurocognitive deficits in these psychotic disorders.

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

International Nuclear Information System (INIS)

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

1981-01-01

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

Sunfall: a collaborative visual analytics system for astrophysics

Energy Technology Data Exchange (ETDEWEB)

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.

Sunfall: a collaborative visual analytics system for astrophysics

International Nuclear Information System (INIS)

Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C

2008-01-01

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

Sunfall: a collaborative visual analytics system for astrophysics

Energy Technology Data Exchange (ETDEWEB)

Aragon, C R; Bailey, S J; Poon, S; Runge, K; Thomas, R C [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: CRAragon@lbl.gov

2008-07-15

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.

Information theoretical assessment of visual communication with wavelet coding

Science.gov (United States)

Rahman, Zia-ur

1995-06-01

A visual communication channel can be characterized by the efficiency with which it conveys information, and the quality of the images restored from the transmitted data. Efficient data representation requires the use of constraints of the visual communication channel. Our information theoretic analysis combines the design of the wavelet compression algorithm with the design of the visual communication channel. Shannon's communication theory, Wiener's restoration filter, and the critical design factors of image gathering and display are combined to provide metrics for measuring the efficiency of data transmission, and for quantitatively assessing the visual quality of the restored image. These metrics are: a) the mutual information (Eta) between the radiance the radiance field and the restored image, and b) the efficiency of the channel which can be roughly measured by as the ratio (Eta) /H, where H is the average number of bits being used to transmit the data. Huck, et al. (Journal of Visual Communication and Image Representation, Vol. 4, No. 2, 1993) have shown that channels desinged to maximize (Eta) , also maximize. Our assessment provides a framework for designing channels which provide the highest possible visual quality for a given amount of data under the critical design limitations of the image gathering and display devices. Results show that a trade-off exists between the maximum realizable information of the channel and its efficiency: an increase in one leads to a decrease in the other. The final selection of which of these quantities to maximize is, of course, application dependent.

Differential Visual Processing of Animal Images, with and without Conscious Awareness.

Science.gov (United States)

Zhu, Weina; Drewes, Jan; Peatfield, Nicholas A; Melcher, David

2016-01-01

The human visual system can quickly and efficiently extract categorical information from a complex natural scene. The rapid detection of animals in a scene is one compelling example of this phenomenon, and it suggests the automatic processing of at least some types of categories with little or no attentional requirements (Li et al., 2002, 2005). The aim of this study is to investigate whether the remarkable capability to categorize complex natural scenes exist in the absence of awareness, based on recent reports that "invisible" stimuli, which do not reach conscious awareness, can still be processed by the human visual system (Pasley et al., 2004; Williams et al., 2004; Fang and He, 2005; Jiang et al., 2006, 2007; Kaunitz et al., 2011a). In two experiments, we recorded event-related potentials (ERPs) in response to animal and non-animal/vehicle stimuli in both aware and unaware conditions in a continuous flash suppression (CFS) paradigm. Our results indicate that even in the "unseen" condition, the brain responds differently to animal and non-animal/vehicle images, consistent with rapid activation of animal-selective feature detectors prior to, or outside of, suppression by the CFS mask.

A Survey on Visual Approaches for Analyzing Scientific Literature and Patents.

Science.gov (United States)

Federico, Paolo; Heimerl, Florian; Koch, Steffen; Miksch, Silvia

2017-09-01

The increasingly large number of available writings describing technical and scientific progress, calls for advanced analytic tools for their efficient analysis. This is true for many application scenarios in science and industry and for different types of writings, comprising patents and scientific articles. Despite important differences between patents and scientific articles, both have a variety of common characteristics that lead to similar search and analysis tasks. However, the analysis and visualization of these documents is not a trivial task due to the complexity of the documents as well as the large number of possible relations between their multivariate attributes. In this survey, we review interactive analysis and visualization approaches of patents and scientific articles, ranging from exploration tools to sophisticated mining methods. In a bottom-up approach, we categorize them according to two aspects: (a) data type (text, citations, authors, metadata, and combinations thereof), and (b) task (finding and comparing single entities, seeking elementary relations, finding complex patterns, and in particular temporal patterns, and investigating connections between multiple behaviours). Finally, we identify challenges and research directions in this area that ask for future investigations.

Coding visual features extracted from video sequences.

Science.gov (United States)

Baroffio, Luca; Cesana, Matteo; Redondi, Alessandro; Tagliasacchi, Marco; Tubaro, Stefano

2014-05-01

Visual features are successfully exploited in several applications (e.g., visual search, object recognition and tracking, etc.) due to their ability to efficiently represent image content. Several visual analysis tasks require features to be transmitted over a bandwidth-limited network, thus calling for coding techniques to reduce the required bit budget, while attaining a target level of efficiency. In this paper, we propose, for the first time, a coding architecture designed for local features (e.g., SIFT, SURF) extracted from video sequences. To achieve high coding efficiency, we exploit both spatial and temporal redundancy by means of intraframe and interframe coding modes. In addition, we propose a coding mode decision based on rate-distortion optimization. The proposed coding scheme can be conveniently adopted to implement the analyze-then-compress (ATC) paradigm in the context of visual sensor networks. That is, sets of visual features are extracted from video frames, encoded at remote nodes, and finally transmitted to a central controller that performs visual analysis. This is in contrast to the traditional compress-then-analyze (CTA) paradigm, in which video sequences acquired at a node are compressed and then sent to a central unit for further processing. In this paper, we compare these coding paradigms using metrics that are routinely adopted to evaluate the suitability of visual features in the context of content-based retrieval, object recognition, and tracking. Experimental results demonstrate that, thanks to the significant coding gains achieved by the proposed coding scheme, ATC outperforms CTA with respect to all evaluation metrics.

Highly efficient red phosphorescent Ir(III) complexes for organic light- emitting diodes based on aryl(6-arylpyridin-3-yl)methanone ligands

Energy Technology Data Exchange (ETDEWEB)

Kang, Hyun Ju; Lee, Kum Hee [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Lee, Seok Jae; Seo, Ji Hyun [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@wow.hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

2011-07-29

A series of phosphorescent Ir(III) complexes 1-4 were synthesized based on aryl(6-arylpyridin-3-yl)methanone ligands, and their photophysical and electroluminescent properties were characterized. Multilayer devices with the configuration, Indium tin oxide/4,4',4''-tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine (60 nm)/4,4'-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (20 nm)/Ir(III) complexes doped in N,N'-dicarbazolyl-4,4'-biphenyl (30 nm, 8%)/2,9-dimethyl-4,7-diphenyl-phenathroline (10 nm)/tris(8-hydroxyquinoline)-aluminum (20 nm)/lithium quinolate (2 nm)/ Al (100 nm), were fabricated. Among these, the device employing complex 2 as a dopant exhibited efficient red emission with a maximum luminance, luminous efficiency, power efficiency and quantum efficiency of 16200 cd/m{sup 2} at 14.0 V, 12.20 cd/A at 20 mA/cm{sup 2}, 4.26 lm/W and 9.26% at 20 mA/cm{sup 2}, respectively, with Commission Internationale de l'Enclairage coordinates of (0.63, 0.37) at 12.0 V.

Lateralized visual behavior in bottlenose dolphins (Tursiops truncatus) performing audio-visual tasks: the right visual field advantage.

Science.gov (United States)

Delfour, F; Marten, K

2006-01-10

Analyzing cerebral asymmetries in various species helps in understanding brain organization. The left and right sides of the brain (lateralization) are involved in different cognitive and sensory functions. This study focuses on dolphin visual lateralization as expressed by spontaneous eye preference when performing a complex cognitive task; we examine lateralization when processing different visual stimuli displayed on an underwater touch-screen (two-dimensional figures, three-dimensional figures and dolphin/human video sequences). Three female bottlenose dolphins (Tursiops truncatus) were submitted to a 2-, 3- or 4-, choice visual/auditory discrimination problem, without any food reward: the subjects had to correctly match visual and acoustic stimuli together. In order to visualize and to touch the underwater target, the dolphins had to come close to the touch-screen and to position themselves using monocular vision (left or right eye) and/or binocular naso-ventral vision. The results showed an ability to associate simple visual forms and auditory information using an underwater touch-screen. Moreover, the subjects showed a spontaneous tendency to use monocular vision. Contrary to previous findings, our results did not clearly demonstrate right eye preference in spontaneous choice. However, the individuals' scores of correct answers were correlated with right eye vision, demonstrating the advantage of this visual field in visual information processing and suggesting a left hemispheric dominance. We also demonstrated that the nature of the presented visual stimulus does not seem to have any influence on the animals' monocular vision choice.

Reduced Graphene Oxide-Immobilized Tris(bipyridine)ruthenium(II) Complex for Efficient Visible-Light-Driven Reductive Dehalogenation Reaction.

Science.gov (United States)

Li, Xiaoyan; Hao, Zhongkai; Zhang, Fang; Li, Hexing

2016-05-18

A sodium benzenesulfonate (PhSO3Na)-functionalized reduced graphene oxide was synthesized via a two-step aryl diazonium coupling and subsequent NaCl ion-exchange procedure, which was used as a support to immobilize tris(bipyridine)ruthenium(II) complex (Ru(bpy)3Cl2) by coordination reaction. This elaborated Ru(bpy)3-rGO catalyst exhibited excellent catalytic efficiency in visible-light-driven reductive dehalogenation reactions under mild conditions, even for ary chloride. Meanwhile, it showed the comparable reactivity with the corresponding homogeneous Ru(bpy)3Cl2 catalyst. This high catalytic performance could be attributed to the unique two-dimensional sheet-like structure of Ru(bpy)3-rGO, which efficiently diminished diffusion resistance of the reactants. Meanwhile, the nonconjugated PhSO3Na-linkage between Ru(II) complex and the support and the very low electrical conductivity of the catalyst inhibited energy/electron transfer from Ru(II) complex to rGO support, resulting in the decreased support-induced quenching effect. Furthermore, it could be easily recycled at least five times without significant loss of catalytic reactivity.

Visual dataflow language for educational robots programming

OpenAIRE

ZIMIN G.A.; MORDVINOV D.A.

2016-01-01

Visual domain-specific languages usually have low entry barrier. Sometimes even children can program on such languages by working with visual representations. This is widely used in educational robotics domain, where most commonly used programming environments are visual. The paper describes a novel dataflow visual programming environment for embedded robotic platforms. Obviously, complex dataflow languages are not simple for understanding. The purpose of our tool is to "bridge" between light...

Complexity Level Analysis Revisited: What Can 30 Years of Hindsight Tell Us about How the Brain Might Represent Visual Information?

Directory of Open Access Journals (Sweden)

John K. Tsotsos

2017-08-01

Full Text Available Much has been written about how the biological brain might represent and process visual information, and how this might inspire and inform machine vision systems. Indeed, tremendous progress has been made, and especially during the last decade in the latter area. However, a key question seems too often, if not mostly, be ignored. This question is simply: do proposed solutions scale with the reality of the brain's resources? This scaling question applies equally to brain and to machine solutions. A number of papers have examined the inherent computational difficulty of visual information processing using theoretical and empirical methods. The main goal of this activity had three components: to understand the deep nature of the computational problem of visual information processing; to discover how well the computational difficulty of vision matches to the fixed resources of biological seeing systems; and, to abstract from the matching exercise the key principles that lead to the observed characteristics of biological visual performance. This set of components was termed complexity level analysis in Tsotsos (1987 and was proposed as an important complement to Marr's three levels of analysis. This paper revisits that work with the advantage that decades of hindsight can provide.

Efficient transfer hydrogenation reaction Catalyzed by a dearomatized PN 3P ruthenium pincer complex under base-free Conditions

KAUST Repository

He, Lipeng

2012-03-01

A dearomatized complex [RuH(PN 3P)(CO)] (PN 3PN, N′-bis(di-tert-butylphosphino)-2,6-diaminopyridine) (3) was prepared by reaction of the aromatic complex [RuH(Cl)(PN 3P)(CO)] (2) with t-BuOK in THF. Further treatment of 3 with formic acid led to the formation of a rearomatized complex (4). These new complexes were fully characterized and the molecular structure of complex 4 was further confirmed by X-ray crystallography. In complex 4, a distorted square-pyramidal geometry around the ruthenium center was observed, with the CO ligand trans to the pyridinic nitrogen atom and the hydride located in the apical position. The dearomatized complex 3 displays efficient catalytic activity for hydrogen transfer of ketones in isopropanol. © 2011 Elsevier B.V. All rights reserved.

On the road to a stronger public health workforce: visual tools to address complex challenges.

Science.gov (United States)

Drehobl, Patricia; Stover, Beth H; Koo, Denise

2014-11-01

The public health workforce is vital to protecting the health and safety of the public, yet for years, state and local governmental public health agencies have reported substantial workforce losses and other challenges to the workforce that threaten the public's health. These challenges are complex, often involve multiple influencing or related causal factors, and demand comprehensive solutions. However, proposed solutions often focus on selected factors and might be fragmented rather than comprehensive. This paper describes approaches to characterizing the situation more comprehensively and includes two visual tools: (1) a fishbone, or Ishikawa, diagram that depicts multiple factors affecting the public health workforce; and (2) a roadmap that displays key elements-goals and strategies-to strengthen the public health workforce, thus moving from the problems depicted in the fishbone toward solutions. The visual tools aid thinking about ways to strengthen the public health workforce through collective solutions and to help leverage resources and build on each other's work. The strategic roadmap is intended to serve as a dynamic tool for partnership, prioritization, and gap assessment. These tools reflect and support CDC's commitment to working with partners on the highest priorities for strengthening the workforce to improve the public's health. Published by Elsevier Inc.

Dual lanthanide-doped complexes: the development of a time-resolved ratiometric fluorescent probe for anthrax biomarker and a paper-based visual sensor.

Science.gov (United States)

Wang, Qi-Xian; Xue, Shi-Fan; Chen, Zi-Han; Ma, Shi-Hui; Zhang, Shengqiang; Shi, Guoyue; Zhang, Min

2017-08-15

In this work, a novel time-resolved ratiometric fluorescent probe based on dual lanthanide (Tb: terbium, and Eu: europium)-doped complexes (Tb/DPA@SiO 2 -Eu/GMP) has been designed for detecting anthrax biomarker (dipicolinic acid, DPA), a unique and major component of anthrax spores. In such complexes-based probe, Tb/DPA@SiO 2 can serve as a stable reference signal with green fluorescence and Eu/GMP act as a sensitive response signal with red fluorescence for ratiometric fluorescent sensing DPA. Additionally, the probe exhibits long fluorescence lifetime, which can significantly reduce the autofluorescence interferences from biological samples by using time-resolved fluorescence measurement. More significantly, a paper-based visual sensor for DPA has been devised by using filter paper embedded with Tb/DPA@SiO 2 -Eu/GMP, and we have proved its utility for fluorescent detection of DPA, in which only a handheld UV lamp is used. In the presence of DPA, the paper-based visual sensor, illuminated by a handheld UV lamp, would result in an obvious fluorescence color change from green to red, which can be easily observed with naked eyes. The paper-based visual sensor is stable, portable, disposable, cost-effective and easy-to-use. The feasibility of using a smartphone with easy-to-access color-scanning APP as the detection platform for quantitative scanometric assays has been also demonstrated by coupled with our proposed paper-based visual sensor. This work unveils an effective method for accurate, sensitive and selective monitoring anthrax biomarker with backgroud-free and self-calibrating properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Data Visualization: Conversion of Data to Animation Files

National Research Council Canada - National Science Library

Kimbler, Nate

2004-01-01

.... Because visualization tools are vital to understanding complex physical phenomena, these visualization tools attempt to facilitate converting data into animations that can be saved and used in data...

Three Cases with Visual Hallucinations following Combined Ocular and Occipital Damage

Directory of Open Access Journals (Sweden)

Bogusław Paradowski

2013-01-01

Full Text Available Charles Bonnet syndrome is an underrecognized disease that involves visual hallucinations in visually impaired patients. We present the cases of three patients who experienced complex visual hallucinations following various pathomechanisms. In two cases, diagnosis showed coexistence of occipital lobe damage with ocular damage, while in the third case it showed occipital lobe damage with retrobulbar optic neuritis. Theories of pathogenesis and the neuroanatomical basis of complex visual hallucinations are discussed and supported by literature review.

Creating Effective Data Visualizations - Lecture 1

CERN Multimedia

CERN. Geneva

2017-01-01

In this course I aim to give an overview of data visualisation as a field, including many of the important theoretical groundings in data visualization. We will explore the different ways of representing visual information, and the strengths/weaknesses of those approaches. Using real-world case studies, I will demonstrate techniques and best practices for visualizing complex multi-dimensional data common to high energy physics and other fields.

Creating Effective Data Visualizations - Lecture 2

CERN Multimedia

CERN. Geneva

2017-01-01

In this course I aim to give an overview of data visualisation as a field, including many of the important theoretical groundings in data visualization. We will explore the different ways of representing visual information, and the strengths/weaknesses of those approaches. Using real-world case studies, I will demonstrate techniques and best practices for visualizing complex multi-dimensional data common to high energy physics and other fields.

Positioning matrix of economic efficiency and complexity: a case study in a university hospital.

Science.gov (United States)

Ippolito, Adelaide; Viggiani, Vincenzo

2014-01-01

At the end of 2010, the Federico II University Hospital in Naples, Italy, initiated a series of discussions aimed at designing and applying a positioning matrix to its departments. This analysis was developed to create a tool able to extract meaningful information both to increase knowledge about individual departments and to inform the choices of general management during strategic planning. The name given to this tool was the positioning matrix of economic efficiency and complexity. In the matrix, the x-axis measures the ratio between revenues and costs, whereas the y-axis measures the index of complexity, thus showing "profitability" while bearing in mind the complexity of activities. By using the positioning matrix, it was possible to conduct a critical analysis of the characteristics of the Federico II University Hospital and to extract useful information for general management to use during strategic planning at the end of 2010 when defining medium-term objectives. Copyright © 2013 John Wiley & Sons, Ltd.

J-TEXT WebScope: An efficient data access and visualization system for long pulse fusion experiment

Energy Technology Data Exchange (ETDEWEB)

Zheng, Wei, E-mail: zhenghaku@gmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology in Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering in Huazhong University of Science and Technology, Wuhan 430074 (China); Wan, Kuanhong; Chen, Zhi; Hu, Feiran; Liu, Qiang [State Key Laboratory of Advanced Electromagnetic Engineering and Technology in Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering in Huazhong University of Science and Technology, Wuhan 430074 (China)

2016-11-15

Highlights: • No matter how large the data is, the response time is always less than 500 milliseconds. • It is intelligent and just gives you the data you want. • It can be accessed directly over the Internet without installing special client software if you already have a browser. • Adopt scale and segment technology to organize data. • To support a new database for the WebScope is quite easy. • With the configuration stored in user’s profile, you have your own portable WebScope. - Abstract: Fusion research is an international collaboration work. To enable researchers across the world to visualize and analyze the experiment data, a web based data access and visualization tool is quite important [1]. Now, a new WebScope based on RIA (Rich Internet Application) is designed and implemented to meet these requirements. On the browser side, a fluent and intuitive interface is provided for researchers at J-TEXT laboratory and collaborators from all over the world to view experiment data and related metadata. The fusion experiments will feature long pulse and high sampling rate in the future. The data access and visualization system in this work has adopted segment and scale concept. Large data samples are re-sampled in different scales and then split into segments for instant response. It allows users to view extremely large data on the web browser efficiently, without worrying about the limitation on the size of the data. The HTML5 and JavaScript based web front-end can provide intuitive and fluent user experience. On the server side, a RESTful (Representational State Transfer) web API, which is based on ASP.NET MVC (Model View Controller), allows users to access the data and its metadata through HTTP (HyperText Transfer Protocol). An interface to the database has been designed to decouple the data access and visualization system from the data storage. It can be applied upon any data storage system like MDSplus or JTEXTDB, and this system is very easy to

J-TEXT WebScope: An efficient data access and visualization system for long pulse fusion experiment

International Nuclear Information System (INIS)

Zheng, Wei; Wan, Kuanhong; Chen, Zhi; Hu, Feiran; Liu, Qiang

2016-01-01

Highlights: • No matter how large the data is, the response time is always less than 500 milliseconds. • It is intelligent and just gives you the data you want. • It can be accessed directly over the Internet without installing special client software if you already have a browser. • Adopt scale and segment technology to organize data. • To support a new database for the WebScope is quite easy. • With the configuration stored in user’s profile, you have your own portable WebScope. - Abstract: Fusion research is an international collaboration work. To enable researchers across the world to visualize and analyze the experiment data, a web based data access and visualization tool is quite important [1]. Now, a new WebScope based on RIA (Rich Internet Application) is designed and implemented to meet these requirements. On the browser side, a fluent and intuitive interface is provided for researchers at J-TEXT laboratory and collaborators from all over the world to view experiment data and related metadata. The fusion experiments will feature long pulse and high sampling rate in the future. The data access and visualization system in this work has adopted segment and scale concept. Large data samples are re-sampled in different scales and then split into segments for instant response. It allows users to view extremely large data on the web browser efficiently, without worrying about the limitation on the size of the data. The HTML5 and JavaScript based web front-end can provide intuitive and fluent user experience. On the server side, a RESTful (Representational State Transfer) web API, which is based on ASP.NET MVC (Model View Controller), allows users to access the data and its metadata through HTTP (HyperText Transfer Protocol). An interface to the database has been designed to decouple the data access and visualization system from the data storage. It can be applied upon any data storage system like MDSplus or JTEXTDB, and this system is very easy to

Highly efficient and heavily-doped organic light-emitting devices based on an orange phosphorescent iridium complex

International Nuclear Information System (INIS)

Zhou, Shunliang; Wang, Qi; Li, Ming; Lu, Zhiyun; Yu, Junsheng

2014-01-01

Heavily doped and highly efficient phosphorescent organic light-emitting devices (PhOLEDs) had been fabricated by utilizing an orange iridium complex, bis[2-(3′,5′-di-tert-butylbiphenyl-4-yl)benzothiazolato-N,C 2' ]iridium(III) (acetylacetonate) [(tbpbt) 2 Ir(acac)], as a phosphor. When the doping concentration of [(tbpbt) 2 Ir(acac)] reached as high as 15 wt%, the PhOLEDs exhibited a power efficiency, current efficiency, and external quantum efficiency of 24.5 lm/W, 32.1 cd/A, 15.7%, respectively, implying a promising quenching-resistant characteristics of this novel phosphor. Furthermore, the efficient white PhOLEDs had been obtained by employing (tbpbt) 2 Ir(acac) as a self-host orange emitter, indicating that (tbpbt) 2 Ir(acac) could serve as a promising phosphor to fabricate white organic light-emitting devices with simplified manufacturing process. - Highlights: • Efficient phosphorescent devices were fabricated. • Optimized phosphor doping ratio reached as high as 15 wt%. • The results proved a promising quench-resistant property of the phosphor. • Efficient white devices based on this phosphor as self-host layer had been realized

Highly efficient and heavily-doped organic light-emitting devices based on an orange phosphorescent iridium complex

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shunliang; Wang, Qi [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Li, Ming [College of Chemistry, Sichuan University, Chengdu, 610064 (China); Lu, Zhiyun, E-mail: luzhiyun@scu.edu.cn [College of Chemistry, Sichuan University, Chengdu, 610064 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

2014-10-15

Heavily doped and highly efficient phosphorescent organic light-emitting devices (PhOLEDs) had been fabricated by utilizing an orange iridium complex, bis[2-(3′,5′-di-tert-butylbiphenyl-4-yl)benzothiazolato-N,C{sup 2'}]iridium(III) (acetylacetonate) [(tbpbt){sub 2}Ir(acac)], as a phosphor. When the doping concentration of [(tbpbt){sub 2}Ir(acac)] reached as high as 15 wt%, the PhOLEDs exhibited a power efficiency, current efficiency, and external quantum efficiency of 24.5 lm/W, 32.1 cd/A, 15.7%, respectively, implying a promising quenching-resistant characteristics of this novel phosphor. Furthermore, the efficient white PhOLEDs had been obtained by employing (tbpbt){sub 2}Ir(acac) as a self-host orange emitter, indicating that (tbpbt){sub 2}Ir(acac) could serve as a promising phosphor to fabricate white organic light-emitting devices with simplified manufacturing process. - Highlights: • Efficient phosphorescent devices were fabricated. • Optimized phosphor doping ratio reached as high as 15 wt%. • The results proved a promising quench-resistant property of the phosphor. • Efficient white devices based on this phosphor as self-host layer had been realized.

Visualizing Practices in Project-based Design

DEFF Research Database (Denmark)

Whyte, Jennifer; Tryggestad, Kjell; Comi, Alice

2016-01-01

Project-based design involves a variety of visual representations, which are evolved to make decisions and accomplish project objectives. Yet, such mediated and distributed ways of working are difficult to capture through ethnographies that examine situated design. A novel approach is developed t...... representations enabled participants in project-based design to develop and share understanding. The complexity of projects and their distributed and mediated nature makes this approach timely and important in addressing new research questions and practical challenges.......Project-based design involves a variety of visual representations, which are evolved to make decisions and accomplish project objectives. Yet, such mediated and distributed ways of working are difficult to capture through ethnographies that examine situated design. A novel approach is developed...... of situated design. This allows the researcher to be nimble, tracing connections across complex engineering projects; reconstructing practices through their visual representations; and observing their effects. Second, it articulates how, in these empirical cases, interaction with a cascade of visual...

Microsphere-liposome complexes protect adenoviral vectors from neutralising antibody without losses in transfection efficiency, in-vitro.

Science.gov (United States)

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Kalle, Wouter H J

2004-11-01

Adenoviral vectors have been commonly used in gene therapy protocols but the success of their use is often limited by the induction of host immunity to the vector. Following exposure to the adenoviral vector, adenoviral-specific neutralising antibodies are produced, which limits further administration. This study examines the effectiveness of a novel combination of microspheres and liposomes for the shielding of adenovirus from neutralising antibodies in an in-vitro setting. We show that liposomes are effective in the protection of adenovirus from neutralising antibody and that the conjugation of these complexes to microspheres augments the level of protection. This study further reveals that previously neutralised adenovirus may still be transported into the cell via liposome-cell interactions and is still capable of expressing its genes, making this vector an effective tool for circumvention of the humoral immune response. We also looked at possible side effects of using the complexes, namely increases in cytotoxicity and reductions in transfection efficiency. Our results showed that varying the liposome:adenovirus ratio can reduce the cytotoxicity of the vector as well as increase the transfection efficiency. In addition, in cell lines that are adenoviral competent, transfection efficiencies on par with uncomplexed adenoviral vectors were achievable with the combination vector.

Associative visual learning by tethered bees in a controlled visual environment.

Science.gov (United States)

Buatois, Alexis; Pichot, Cécile; Schultheiss, Patrick; Sandoz, Jean-Christophe; Lazzari, Claudio R; Chittka, Lars; Avarguès-Weber, Aurore; Giurfa, Martin

2017-10-10

Free-flying honeybees exhibit remarkable cognitive capacities but the neural underpinnings of these capacities cannot be studied in flying insects. Conversely, immobilized bees are accessible to neurobiological investigation but display poor visual learning. To overcome this limitation, we aimed at establishing a controlled visual environment in which tethered bees walking on a spherical treadmill learn to discriminate visual stimuli video projected in front of them. Freely flying bees trained to walk into a miniature Y-maze displaying these stimuli in a dark environment learned the visual discrimination efficiently when one of them (CS+) was paired with sucrose and the other with quinine solution (CS-). Adapting this discrimination to the treadmill paradigm with a tethered, walking bee was successful as bees exhibited robust discrimination and preferred the CS+ to the CS- after training. As learning was better in the maze, movement freedom, active vision and behavioral context might be important for visual learning. The nature of the punishment associated with the CS- also affects learning as quinine and distilled water enhanced the proportion of learners. Thus, visual learning is amenable to a controlled environment in which tethered bees learn visual stimuli, a result that is important for future neurobiological studies in virtual reality.

Rapid visualization of latent fingermarks using gold seed-mediated enhancement

Directory of Open Access Journals (Sweden)

Chia-Hao Su

2016-11-01

Full Text Available Abstract Background Fingermarks are one of the most important and useful forms of physical evidence in forensic investigations. However, latent fingermarks are not directly visible, but can be visualized due to the presence of other residues (such as inorganic salts, proteins, polypeptides, enzymes and human metabolites which can be detected or recognized through various strategies. Convenient and rapid techniques are still needed to provide obvious contrast between the background and the fingermark ridges and to then visualize latent fingermark with a high degree of selectivity and sensitivity. Results In this work, lysozyme-binding aptamer-conjugated Au nanoparticles (NPs are used to recognize and target lysozyme in the fingermark ridges, and Au+-complex solution is used as a growth agent to reduce Au+ from Au+ to Au0 on the surface of the Au NPs. Distinct fingermark patterns were visualized on a range of professional forensic within 3 min; the resulting images could be observed by the naked eye without background interference. The entire processes from fingermark collection to visualization only entails two steps and can be completed in less than 10 min. The proposed method provides cost and time savings over current fingermark visualization methods. Conclusions We report a simple, inexpensive, and fast method for the rapid visualization of latent fingermarks on the non-porous substrates using Au seed-mediated enhancement. Au seed-mediated enhancement is used to achieve the rapid visualization of latent fingermarks on non-porous substrates by the naked eye without the use of expensive or sophisticated instruments. The proposed approach offers faster detection and visualization of latent fingermarks than existing methods. The proposed method is expected to increase detection efficiency for latent fingermarks and reduce time requirements and costs for forensic investigations.

Customizable Visualizations with Formula-Linked Building Blocks

DEFF Research Database (Denmark)

Kuhail, Mohammad Amin; Lauesen, Søren

different appearance or behavior than what the widgets support. Another approach is to combine primitive graphical elements using traditional programming or visualization toolkits. Traditional programming allows high customizability, but it is time consuming and hard to develop advanced visualizations......One approach to visualization construction is to use complex blocks (widgets) that are tailored for specific visualizations, and customize the visualizations by setting the properties of the widgets. This approach allows fast and easy visualization construction but falls short if the user wants....... Visualization toolkits allow easier visualization creation in some cases, but customization and interaction are tedious. As an alternative, we developed uVis visualization tool that uses spreadsheet-like formulas to connect building blocks. uVis formulas can refer to building blocks and database tables. We...

Visual perception and medical imaging

International Nuclear Information System (INIS)

Jaffe, C.C.

1985-01-01

Medical imaging represents a particularly distinct discipline for image processing since it uniquely depends on the ''expert observer'' and yet models of the human visual system are totally inadequate at the complex level to allow satisfactory prediction of observer response to a given image modification. An illustration of the difficulties in assessing observer performance is shown by a series of optical illustrations which demonstrate that net cognitive behavior is not readily predictable. Although many of these phenomena are often considered as exceptional visual events, the setting of complex images makes it difficult to entirely exclude at least partial operation of these impairments during performance of the diagnostic medical imaging task

LOD map--A visual interface for navigating multiresolution volume visualization.

Science.gov (United States)

Wang, Chaoli; Shen, Han-Wei

2006-01-01

In multiresolution volume visualization, a visual representation of level-of-detail (LOD) quality is important for us to examine, compare, and validate different LOD selection algorithms. While traditional methods rely on ultimate images for quality measurement, we introduce the LOD map--an alternative representation of LOD quality and a visual interface for navigating multiresolution data exploration. Our measure for LOD quality is based on the formulation of entropy from information theory. The measure takes into account the distortion and contribution of multiresolution data blocks. A LOD map is generated through the mapping of key LOD ingredients to a treemap representation. The ordered treemap layout is used for relative stable update of the LOD map when the view or LOD changes. This visual interface not only indicates the quality of LODs in an intuitive way, but also provides immediate suggestions for possible LOD improvement through visually-striking features. It also allows us to compare different views and perform rendering budget control. A set of interactive techniques is proposed to make the LOD adjustment a simple and easy task. We demonstrate the effectiveness and efficiency of our approach on large scientific and medical data sets.

Information visualization for the Structural Complexity Management Approach

OpenAIRE

Maurer, Maik;Braun, Thomas;Lindemann, Udo

2017-01-01

The handling of complexity poses an important challenge and a success factor for product design. A considerable percentage of complexity results from dependencies between system elements – as adaptations to single system elements can cause far-reaching consequences. The Structural Complexity Management (SCM) approach provides a five-step procedure that supports users in the identification, acquisition, analysis and optimization of system dependencies. The approach covers the handling of multi...

The effects of acute bout of cycling on auditory & visual reaction times.

Science.gov (United States)

Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

2015-04-01

The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Visualization, Light Transport, and Big Data

CERN Multimedia

CERN. Geneva

2014-01-01

Scientific data treated by current peta-scale computers and coming exa-scale computers is quite huge and it is known as "Big Data". For a better understanding and analysis of this massive amount of information, visualization is an important task. Large scale, efficient, and visually compelling visualization has many challenges. In this talk, I will introduce the most promising visualization technique for big data. Namely, ray tracing method from Light Transport theory and image composition. I will also show some recent large scale visualization results using this technique on the K computer, a 10 peta-flops supercomputer with up to 65,536 computing nodes. About the speaker Please find the speaker's LinkedIn profile here.

A visible-light-excited europium(III) complex-based luminescent probe for visualizing copper ions and hydrogen sulfide in living cells

Science.gov (United States)

Wang, Yiren; Wang, Huan; Yang, Mei; Yuan, Jingli; Wu, Jing

2018-01-01

Development of visible-light-excited lanthanide (III) complex-based luminescent probes is highly appealing due to their superiority of less damage to the living biosystems over the conventional UV-light-excited ones. In this work, a visible-light-excited europium (III) complex-based luminescent probe, BPED-BHHCT-Eu3+-BPT, has been designed and synthesized by conjugating the Cu2+-binding N,N-bis(2-pyridylmethyl)ethanediamine (BPED) to a tetradentate β-diketone ligand 4,4‧-bis(1″,1″,1″,2″,2″,3″,3″-heptafluoro-4″,6″-hexanedione-6″-yl)chlorosulfo-o-terphenyl (BHHCT) and coordinating with a coligand 2-(N,N-diethylanilin-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-triazine) (BPT) for the time-gated luminescence detection of Cu2+ ions and hydrogen sulfide (H2S) in living cells. BPED-BHHCT-Eu3+-BPT exhibited a sharp excitation peak at 407 nm and a wide excitation window extending to beyond 460 nm. Upon its reaction with Cu2+ ions, the luminescence of BPED-BHHCT-Eu3+-BPT was efficiently quenched, which could be reversibly restored by the addition of H2S due to the strong affinity between Cu2+ ions and H2S. The "on-off-on" type luminescence behavior of BPED-BHHCT-Eu3+-BPT towards Cu2+ ions and H2S enabled the sensing of the two species with high sensitivity and selectivity. The performances of BPED-BHHCT-Eu3+-BPT for visualizing intracellular Cu2+ ions and H2S were investigated, and the results have demonstrated the practical applicability of the probe for molecular imaging of cells.

Scalable modulation technology and the tradeoff of reach, spectral efficiency, and complexity

Science.gov (United States)

Bosco, Gabriella; Pilori, Dario; Poggiolini, Pierluigi; Carena, Andrea; Guiomar, Fernando

2017-01-01

Bandwidth and capacity demand in metro, regional, and long-haul networks is increasing at several tens of percent per year, driven by video streaming, cloud computing, social media and mobile applications. To sustain this traffic growth, an upgrade of the widely deployed 100-Gbit/s long-haul optical systems, based on polarization multiplexed quadrature phase-shift keying (PM-QPSK) modulation format associated with coherent detection and digital signal processing (DSP), is mandatory. In fact, optical transport techniques enabling a per-channel bit rate beyond 100 Gbit/s have recently been the object of intensive R and D activities, aimed at both improving the spectral efficiency and lowering the cost per bit in fiber transmission systems. In this invited contribution, we review the different available options to scale the per-channel bit-rate to 400 Gbit/s and beyond, i.e. symbol-rate increase, use of higher-order quadrature amplitude modulation (QAM) modulation formats and use of super-channels with DSP-enabled spectral shaping and advanced multiplexing technologies. In this analysis, trade-offs of system reach, spectral efficiency and transceiver complexity are addressed. Besides scalability, next generation optical networks will require a high degree of flexibility in the transponders, which should be able to dynamically adapt the transmission rate and bandwidth occupancy to the light path characteristics. In order to increase the flexibility of these transponders (often referred to as "flexponders"), several advanced modulation techniques have recently been proposed, among which sub-carrier multiplexing, hybrid formats (over time, frequency and polarization), and constellation shaping. We review these techniques, highlighting their limits and potential in terms of performance, complexity and flexibility.

High-efficiency and heavily doped organic light-emitting devices based on quench-resistant red iridium complex

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhao, Juan; Wang, Jun [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Li, Ming [College of Chemistry, Sichuan University, Chengdu 610064 (China); Lu, Zhiyun, E-mail: luzhiyun@scu.edu.cn [College of Chemistry, Sichuan University, Chengdu 610064 (China)

2013-02-15

Highly efficient red phosphorescent organic light-emitting devices had been fabricated using a new iridium complex, bis[2-(9,9-dimethyl-9H-fluoren-2-yl) benzothiazolato-N,C{sup 2'}]iridium(III) (acetylacetonate) [(fbt){sub 2}Ir(acac)] as phosphor. With a high doping concentration of 15 wt%, the device exhibited a maximum luminance efficiency, power efficiency and external quantum efficiency (EQE) of 35.2 cd/A, 21.3 lm/W, 18.2%, respectively, indicating an excellent quench-resistant property of (fbt){sub 2}Ir(acac). The results are appealing towards the development of 'easy-to-make' OLEDs. It has been demonstrated that the high efficiency arises from more balanced charge carriers in the emissive layer. - Highlight: Black-Right-Pointing-Pointer We obtained efficient OLEDs based on newly synthesized quench-resistant phosphor. Black-Right-Pointing-Pointer Peak performance was obtained with 15 wt% (fbt){sub 2}Ir(acac) doped device. Black-Right-Pointing-Pointer Our devices gave one of the best performance among heavily-doped red devices. Black-Right-Pointing-Pointer Balanced carrier transport is crucial for the high performance of our devices.

Unraveling the Complexity of the Jevons Paradox: The Link Between Innovation, Efficiency, and Sustainability

Directory of Open Access Journals (Sweden)

Mario Giampietro

2018-04-01

Full Text Available The term “Jevons Paradox” flags the need to consider the different hierarchical scales at which a system under analysis changes its identity in response to an innovation. Accordingly, an analysis of the implications of the Jevons Paradox must abandon the realm of reductionism and deal with the complexity inherent in the issue of sustainability: when studying evolution and real change how can we define “what has to be sustained” in a system that continuously becomes something else? In an attempt to address this question this paper presents three theoretical concepts foreign to conventional scientific analysis: (i complex adaptive systems—to address the peculiar characteristics of learning and self-producing systems; (ii holons and holarchy—to explain the implications of the ambiguity found when observing the relation between functional and structural elements across different scales (steady-state vs. evolution; and (iii Holling's adaptive cycle—to illustrate the existence of different phases in the evolutionary trajectory of a complex adaptive system interacting with its context in which either external or internal constraints can become limiting. These concepts are used to explain systemic drivers of the Jevons Paradox. Looking at society's thermodynamic foundations, sustainability is based on a dynamic balance of two contrasting principles regulating the evolution of complex adaptive systems: the minimum entropy production and the maximum energy flux. The co-existence of these two principles explains why in different situations innovation has to play a different role in the “sustainable development” of society: (i when society is not subject to external biophysical constraints improvements in efficiency serve to increase the final consumption of society and expand its diversity of functions and structures; (ii when the expansion of society is limited by external constraints improvements in efficiency should be used to avoid as

Environmental influences on neural systems of relational complexity

Directory of Open Access Journals (Sweden)

Layne eKalbfleisch

2013-09-01

Full Text Available Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC, defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task. To specify the contributions of sensory demand and relational integration to reasoning, our participants performed a non-verbal matrix task comprised of color, no-color line, or black-white visual contrast conditions parametrically varied by complexity (relations 0, 1, 2. The use of matrix reasoning is ecologically valid for its psychometric relevance and for its potential to link the processing of psychophysically specific visual properties with various levels of relational complexity during reasoning. The role of these elements is important because matrix tests assess intellectual aptitude based on these seemingly context-less exercises. This experiment is a first step toward examining the psychophysical underpinnings of performance on these types of problems. The importance of this is increased in light of recent evidence that intelligence can be linked to visual discrimination. We submit three main findings. First, color and black-white visual contrast add demand at a basic sensory level, but contributions from color and from black-white visual contrast are dissociable in cortex such that color engages a reasoning heuristic and black-white visual contrast engages a sensory heuristic. Second, color supports contextual sense-making by boosting salience resulting in faster problem solving. Lastly, when visual complexity reaches 2-relations, color and visual contrast relinquish salience to other dimensions of problem

Processing speed training increases the efficiency of attentional resource allocation in young adults

Directory of Open Access Journals (Sweden)

Wesley K Burge

2013-10-01

Full Text Available Cognitive training has been shown to improve performance on a range of tasks. However, the mechanisms underlying these improvements are still unclear. Given the wide range of transfer effects, it is likely that these effects are due to a factor common to a wide range of tasks. One such factor is a participant’s efficiency in allocating limited cognitive resources. The impact of a cognitive training program, Processing Speed Training (PST, on the allocation of resources to a set of visual tasks was measured using pupillometry in 10 young adults as compared to a control group of a 10 young adults (n = 20. PST is a well-studied computerized training program that involves identifying simultaneously presented central and peripheral stimuli. As training progresses, the task becomes increasingly more difficult, by including peripheral distracting stimuli and decreasing the duration of stimulus presentation. Analysis of baseline data confirmed that pupil diameter reflected cognitive effort. After training, participants randomized to PST used fewer attentional resources to perform complex visual tasks as compared to the control group. These pupil diameter data indicated that PST appears to increase the efficiency of attentional resource allocation. Increases in cognitive efficiency have been hypothesized to underlie improvements following experience with action video games, and improved cognitive efficiency has been hypothesized to underlie the benefits of processing speed training in older adults. These data reveal that these training schemes may share a common underlying mechanism of increasing cognitive efficiency in younger adults.

Visuals Matter! Designing and using effective visual representations to support project and portfolio decisions

DEFF Research Database (Denmark)

Geraldi, Joana; Arlt, Mario

. They can help managers to be sharper and quicker, especially if visuals are used in a mindful manner. The intent of this book is to increase the awareness of project, program and portfolio practitioners and scholars about the importance of visuals and to provide practical recommendations on how they can......This book is the result of a two-year research project, funded by Project Management Institute and University College London on data visualization in the project and portfolio management contexts. Visuals are powerful and constitute an integral part of analyzing problems and making decisions...... be used and designed mindfully. The research, which underpins this book, focuses on the impact of visuals on cognition of data in project portfolio decisions. The complexity of portfolio problems often exceed human cognitive limitations as a result of a number of factors, such as the large number...

Visualization-by-Sketching: An Artist's Interface for Creating Multivariate Time-Varying Data Visualizations.

Science.gov (United States)

Schroeder, David; Keefe, Daniel F

2016-01-01

We present Visualization-by-Sketching, a direct-manipulation user interface for designing new data visualizations. The goals are twofold: First, make the process of creating real, animated, data-driven visualizations of complex information more accessible to artists, graphic designers, and other visual experts with traditional, non-technical training. Second, support and enhance the role of human creativity in visualization design, enabling visual experimentation and workflows similar to what is possible with traditional artistic media. The approach is to conceive of visualization design as a combination of processes that are already closely linked with visual creativity: sketching, digital painting, image editing, and reacting to exemplars. Rather than studying and tweaking low-level algorithms and their parameters, designers create new visualizations by painting directly on top of a digital data canvas, sketching data glyphs, and arranging and blending together multiple layers of animated 2D graphics. This requires new algorithms and techniques to interpret painterly user input relative to data "under" the canvas, balance artistic freedom with the need to produce accurate data visualizations, and interactively explore large (e.g., terabyte-sized) multivariate datasets. Results demonstrate a variety of multivariate data visualization techniques can be rapidly recreated using the interface. More importantly, results and feedback from artists support the potential for interfaces in this style to attract new, creative users to the challenging task of designing more effective data visualizations and to help these users stay "in the creative zone" as they work.

Fault-patch stress-transfer efficiency in presence of sub-patch geometric complexity

KAUST Repository

Zielke, Olaf

2015-04-01

It is well known that faults are not planar surfaces. Instead they exhibit self-similar or self-affine properties that span a wide range of spatial (sub-micrometer to tens-of-kilometer). This geometric fault roughness has a distinct impact on amount and distribution of stresses/strains induced in the medium and on other portions of the fault. However, when numerically simulated (for example in multi-cycle EQ rupture simulations or Coulomb failure stress calculations) this roughness is largely ignored: individual fault patches --the incremental elements that build the fault surface in the respective computer models-- are planar and fault roughness at this and lower spatial scales is not considered. As a result, the fault-patch stress-transfer efficiency may be systematically too large in those numerical simulations with respect to the "actual" efficiency level. Here, we investigate the effect of sub-patch geometric complexity on fault-patch stress-transfer efficiency. For that, we sub-divide a fault patch (e.g., 1x1km) into a large number of sub-patches (e.g., 20x20m) and determine amount of induced stresses at selected positions around that patch for different levels and realizations of fault roughness. For each fault roughness level, we compute mean and standard deviation of the induced stresses, enabling us to compute the coefficient of variation. We normalize those values with stresses from the corresponding single (planar) fault patch, providing scaling factors and their variability for stress transfer efficiency. Given a certain fault roughness that is assumed for a fault, this work provides the means to implement the sub-patch fault roughness into investigations based on fault-patch interaction schemes.

Data mining and visualization techniques

Science.gov (United States)

Wong, Pak Chung [Richland, WA; Whitney, Paul [Richland, WA; Thomas, Jim [Richland, WA

2004-03-23

Disclosed are association rule identification and visualization methods, systems, and apparatus. An association rule in data mining is an implication of the form X.fwdarw.Y where X is a set of antecedent items and Y is the consequent item. A unique visualization technique that provides multiple antecedent, consequent, confidence, and support information is disclosed to facilitate better presentation of large quantities of complex association rules.

Visual dysfunction in Parkinson’s disease

Science.gov (United States)

Weil, Rimona S.; Schrag, Anette E.; Warren, Jason D.; Crutch, Sebastian J.; Lees, Andrew J.; Morris, Huw R.

2016-01-01

Patients with Parkinson’s disease have a number of specific visual disturbances. These include changes in colour vision and contrast sensitivity and difficulties with complex visual tasks such as mental rotation and emotion recognition. We review changes in visual function at each stage of visual processing from retinal deficits, including contrast sensitivity and colour vision deficits to higher cortical processing impairments such as object and motion processing and neglect. We consider changes in visual function in patients with common Parkinson’s disease-associated genetic mutations including GBA and LRRK2. We discuss the association between visual deficits and clinical features of Parkinson’s disease such as rapid eye movement sleep behavioural disorder and the postural instability and gait disorder phenotype. We review the link between abnormal visual function and visual hallucinations, considering current models for mechanisms of visual hallucinations. Finally, we discuss the role of visuo-perceptual testing as a biomarker of disease and predictor of dementia in Parkinson’s disease. PMID:27412389

Learning representation hierarchies by sharing visual features: a computational investigation of Persian character recognition with unsupervised deep learning.

Science.gov (United States)

Sadeghi, Zahra; Testolin, Alberto

2017-08-01

In humans, efficient recognition of written symbols is thought to rely on a hierarchical processing system, where simple features are progressively combined into more abstract, high-level representations. Here, we present a computational model of Persian character recognition based on deep belief networks, where increasingly more complex visual features emerge in a completely unsupervised manner by fitting a hierarchical generative model to the sensory data. Crucially, high-level internal representations emerging from unsupervised deep learning can be easily read out by a linear classifier, achieving state-of-the-art recognition accuracy. Furthermore, we tested the hypothesis that handwritten digits and letters share many common visual features: A generative model that captures the statistical structure of the letters distribution should therefore also support the recognition of written digits. To this aim, deep networks trained on Persian letters were used to build high-level representations of Persian digits, which were indeed read out with high accuracy. Our simulations show that complex visual features, such as those mediating the identification of Persian symbols, can emerge from unsupervised learning in multilayered neural networks and can support knowledge transfer across related domains.

The role of memory for visual search in scenes.

Science.gov (United States)

Le-Hoa Võ, Melissa; Wolfe, Jeremy M

2015-03-01

Many daily activities involve looking for something. The ease with which these searches are performed often allows one to forget that searching represents complex interactions between visual attention and memory. Although a clear understanding exists of how search efficiency will be influenced by visual features of targets and their surrounding distractors or by the number of items in the display, the role of memory in search is less well understood. Contextual cueing studies have shown that implicit memory for repeated item configurations can facilitate search in artificial displays. When searching more naturalistic environments, other forms of memory come into play. For instance, semantic memory provides useful information about which objects are typically found where within a scene, and episodic scene memory provides information about where a particular object was seen the last time a particular scene was viewed. In this paper, we will review work on these topics, with special emphasis on the role of memory in guiding search in organized, real-world scenes. © 2015 New York Academy of Sciences.

Teach yourself visually Apple Watch

CERN Document Server

Hart-Davis, Guy

2015-01-01

Master your new smartwatch quickly and easily with this highly visual guide Teach Yourself VISUALLY Apple Watch is a practical, accessible guide to mastering the powerful features and functionality of your new smartwatch. For Apple devotees and new users alike, this easy-to-follow guide features visually rich tutorials and step-by-step instructions that show you how to take advantage of all of the Apple watch's capabilities. You'll learn how to track your health, control household devices, download and install apps, sync your music, sync other Apple devices, and efficiently use the current O

Complex analysis of energy efficiency in operated high-rise residential building: Case study

Science.gov (United States)

Korniyenko, Sergey

2018-03-01

Energy conservation and human thermal comfort enhancement in buildings is a topical issue of modern architecture and construction. The innovative solution of this problem makes it possible to enhance building ecological and maintenance safety, to reduce hydrocarbon fuel consumption, and to improve life standard of people. The requirements to increase of energy efficiency in buildings should be provided at all the stages of building's life cycle that is at the stage of design, construction and maintenance of buildings. The research purpose is complex analysis of energy efficiency in operated high-rise residential building. Many actions for building energy efficiency are realized according to the project; mainly it is the effective building envelope and engineering systems. Based on results of measurements the energy indicators of the building during annual period have been calculated. The main reason of increase in heat losses consists in the raised infiltration of external air in the building through a building envelope owing to the increased air permeability of windows and balcony doors (construction defects). Thermorenovation of the building based on ventilating and infiltration heat losses reduction through a building envelope allows reducing annual energy consumption. Energy efficiency assessment based on the total annual energy consumption of building, including energy indices for heating and a ventilation, hot water supply and electricity supply, in comparison with heating is more complete. The account of various components in building energy balance completely corresponds to modern direction of researches on energy conservation and thermal comfort enhancement in buildings.

Effects of Temporal Congruity Between Auditory and Visual Stimuli Using Rapid Audio-Visual Serial Presentation.

Science.gov (United States)

An, Xingwei; Tang, Jiabei; Liu, Shuang; He, Feng; Qi, Hongzhi; Wan, Baikun; Ming, Dong

2016-10-01

Combining visual and auditory stimuli in event-related potential (ERP)-based spellers gained more attention in recent years. Few of these studies notice the difference of ERP components and system efficiency caused by the shifting of visual and auditory onset. Here, we aim to study the effect of temporal congruity of auditory and visual stimuli onset on bimodal brain-computer interface (BCI) speller. We designed five visual and auditory combined paradigms with different visual-to-auditory delays (-33 to +100 ms). Eleven participants attended in this study. ERPs were acquired and aligned according to visual and auditory stimuli onset, respectively. ERPs of Fz, Cz, and PO7 channels were studied through the statistical analysis of different conditions both from visual-aligned ERPs and audio-aligned ERPs. Based on the visual-aligned ERPs, classification accuracy was also analyzed to seek the effects of visual-to-auditory delays. The latencies of ERP components depended mainly on the visual stimuli onset. Auditory stimuli onsets influenced mainly on early component accuracies, whereas visual stimuli onset determined later component accuracies. The latter, however, played a dominate role in overall classification. This study is important for further studies to achieve better explanations and ultimately determine the way to optimize the bimodal BCI application.

High-efficiency tris(8-hydroxyquinoline)aluminum (Alq3) complexes for organic white-light-emitting diodes and solid-state lighting.

Science.gov (United States)

Pérez-Bolívar, César; Takizawa, Shin-ya; Nishimura, Go; Montes, Victor A; Anzenbacher, Pavel

2011-08-08

Combinations of electron-withdrawing and -donating substituents on the 8-hydroxyquinoline ligand of the tris(8-hydroxyquinoline)aluminum (Alq(3)) complexes allow for control of the HOMO and LUMO energies and the HOMO-LUMO gap responsible for emission from the complexes. Here, we present a systematic study on tuning the emission and electroluminescence (EL) from Alq(3) complexes from the green to blue region. In this study, we explored the combination of electron-donating substituents on C4 and C6. Compounds 1-6 displayed the emission tuning between 478 and 526 nm, and fluorescence quantum yield between 0.15 and 0.57. The compounds 2-6 were used as emitters and hosts in organic light-emitting diodes (OLEDs). The highest OLED external quantum efficiency (EQE) observed was 4.6%, which is among the highest observed for Alq(3) complexes. Also, the compounds 3-5 were used as hosts for red phosphorescent dopants to obtain white light-emitting diodes (WOLED). The WOLEDs displayed high efficiency (EQE up to 19%) and high white color purity (color rendering index (CRI≈85). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hierarchically organized layout for visualization of biochemical pathways.

Science.gov (United States)

Tsay, Jyh-Jong; Wu, Bo-Liang; Jeng, Yu-Sen

2010-01-01

Many complex pathways are described as hierarchical structures in which a pathway is recursively partitioned into several sub-pathways, and organized hierarchically as a tree. The hierarchical structure provides a natural way to visualize the global structure of a complex pathway. However, none of the previous research on pathway visualization explores the hierarchical structures provided by many complex pathways. In this paper, we aim to develop algorithms that can take advantages of hierarchical structures, and give layouts that explore the global structures as well as local structures of pathways. We present a new hierarchically organized layout algorithm to produce layouts for hierarchically organized pathways. Our algorithm first decomposes a complex pathway into sub-pathway groups along the hierarchical organization, and then partition each sub-pathway group into basic components. It then applies conventional layout algorithms, such as hierarchical layout and force-directed layout, to compute the layout of each basic component. Finally, component layouts are joined to form a final layout of the pathway. Our main contribution is the development of algorithms for decomposing pathways and joining layouts. Experiment shows that our algorithm is able to give comprehensible visualization for pathways with hierarchies, cycles as well as complex structures. It clearly renders the global component structures as well as the local structure in each component. In addition, it runs very fast, and gives better visualization for many examples from previous related research. 2009 Elsevier B.V. All rights reserved.

Graph-based clustering and data visualization algorithms

CERN Document Server

Vathy-Fogarassy, Ágnes

2013-01-01

This work presents a data visualization technique that combines graph-based topology representation and dimensionality reduction methods to visualize the intrinsic data structure in a low-dimensional vector space. The application of graphs in clustering and visualization has several advantages. A graph of important edges (where edges characterize relations and weights represent similarities or distances) provides a compact representation of the entire complex data set. This text describes clustering and visualization methods that are able to utilize information hidden in these graphs, based on

Visual impairment secondary to congenital glaucoma in children: visual responses, optical correction and use of low vision AIDS

Directory of Open Access Journals (Sweden)

Maria Aparecida Onuki Haddad

2009-01-01

Full Text Available INTRODUCTION: Congenital glaucoma is frequently associated with visual impairment due to optic nerve damage, corneal opacities, cataracts and amblyopia. Poor vision in childhood is related to global developmental problems, and referral to vision habilitation/rehabilitation services should be without delay to promote efficient management of the impaired vision. OBJECTIVE: To analyze data concerning visual response, the use of optical correction and prescribed low vision aids in a population of children with congenital glaucoma. METHOD: The authors analyzed data from 100 children with congenital glaucoma to assess best corrected visual acuity, prescribed optical correction and low vision aids. RESULTS: Fifty-five percent of the sample were male, 43% female. The mean age was 6.3 years. Two percent presented normal visual acuity levels, 29% mild visual impairment, 28% moderate visual impairment, 15% severe visual impairment, 11% profound visual impairment, and 15% near blindness. Sixty-eight percent received optical correction for refractive errors. Optical low vision aids were adopted for distance vision in 34% of the patients and for near vision in 6%. A manual monocular telescopic system with 2.8 × magnification was the most frequently prescribed low vision aid for distance, and for near vision a +38 diopter illuminated stand magnifier was most frequently prescribed. DISCUSSION AND CONCLUSION: Careful low vision assessment and the appropriate prescription of optical corrections and low vision aids are mandatory in children with congenital glaucoma, since this will assist their global development, improving efficiency in daily life activities and promoting social and educational inclusion.

A Multilevel Gamma-Clustering Layout Algorithm for Visualization of Biological Networks

Science.gov (United States)

Hruz, Tomas; Lucas, Christoph; Laule, Oliver; Zimmermann, Philip

2013-01-01

Visualization of large complex networks has become an indispensable part of systems biology, where organisms need to be considered as one complex system. The visualization of the corresponding network is challenging due to the size and density of edges. In many cases, the use of standard visualization algorithms can lead to high running times and poorly readable visualizations due to many edge crossings. We suggest an approach that analyzes the structure of the graph first and then generates a new graph which contains specific semantic symbols for regular substructures like dense clusters. We propose a multilevel gamma-clustering layout visualization algorithm (MLGA) which proceeds in three subsequent steps: (i) a multilevel γ-clustering is used to identify the structure of the underlying network, (ii) the network is transformed to a tree, and (iii) finally, the resulting tree which shows the network structure is drawn using a variation of a force-directed algorithm. The algorithm has a potential to visualize very large networks because it uses modern clustering heuristics which are optimized for large graphs. Moreover, most of the edges are removed from the visual representation which allows keeping the overview over complex graphs with dense subgraphs. PMID:23864855

Visualizing the Arithmetic of Complex Numbers

Science.gov (United States)

Soto-Johnson, Hortensia

2014-01-01

The Common Core State Standards Initiative stresses the importance of developing a geometric and algebraic understanding of complex numbers in their different forms (i.e., Cartesian, polar and exponential). Unfortunately, most high school textbooks do not offer such explanations much less exercises that encourage students to bridge geometric and…

Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

Science.gov (United States)

Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

2015-11-01

In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

A visual approach for modeling spatiotemporal relations

NARCIS (Netherlands)

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

2008-01-01

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

Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells

International Nuclear Information System (INIS)

Huang, Jian-Feng; Liu, Jun-Min; Su, Pei-Yang; Chen, Yi-Fan; Shen, Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong

2015-01-01

Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF 3 -sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF 3 and D-bisCF 3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF 3 , D-CF 3 , D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF 3 , CF 3 , OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF 3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF 3 , D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF 3 and -OH groups at the TiO 2 surface, moderate dye loading on TiO 2 , and high charge collection efficiency. Moreover, the D-bisCF 3 and D-CF 3 based DSSCs exhibit good stability under 100 mW cm −2 light soaking at 60 °C for 400 h

Relationship between macular ganglion cell complex parameters and visual field parameters after tumor resection in chiasmal compression.

Science.gov (United States)

Ohkubo, Shinji; Higashide, Tomomi; Takeda, Hisashi; Murotani, Eiji; Hayashi, Yasuhiko; Sugiyama, Kazuhisa

2012-01-01

To evaluate the relationship between macular ganglion cell complex (GCC) parameters and visual field (VF) parameters in chiasmal compression and the potential for GCC parameters in order to predict the short-term postsurgical VF. Twenty-three eyes of 12 patients with chiasmal compression and 33 control eyes were studied. All patients underwent transsphenoidal tumor resection. Before surgery a 3D scan of the macula was taken using spectral-domain optical coherence tomography. All patients underwent Humphrey 24-2 VF testing after surgery. Spearman's rank correlation coefficients were used to evaluate the relationship between the GCC parameters and VF parameters [mean deviation (MD), pattern standard deviation]. Coefficients of determination (R2) were calculated using linear regression. Average thickness in the patients was significantly thinner than that of controls. Average thickness, global loss volume and focal loss volume (FLV) significantly correlated with the MD. We observed the greatest R2 between FLV and MD. Examining the macular GCC was useful for evaluating structural damage in patients with chiasmal compression. Preoperative GCC parameters, especially FLV, may be useful in predicting visual function following surgical decompression of chiasmal compression.

Visual motion imagery neurofeedback based on the hMT+/V5 complex: evidence for a feedback-specific neural circuit involving neocortical and cerebellar regions

Science.gov (United States)

Banca, Paula; Sousa, Teresa; Catarina Duarte, Isabel; Castelo-Branco, Miguel

2015-12-01

Objective. Current approaches in neurofeedback/brain-computer interface research often focus on identifying, on a subject-by-subject basis, the neural regions that are best suited for self-driven modulation. It is known that the hMT+/V5 complex, an early visual cortical region, is recruited during explicit and implicit motion imagery, in addition to real motion perception. This study tests the feasibility of training healthy volunteers to regulate the level of activation in their hMT+/V5 complex using real-time fMRI neurofeedback and visual motion imagery strategies. Approach. We functionally localized the hMT+/V5 complex to further use as a target region for neurofeedback. An uniform strategy based on motion imagery was used to guide subjects to neuromodulate hMT+/V5. Main results. We found that 15/20 participants achieved successful neurofeedback. This modulation led to the recruitment of a specific network as further assessed by psychophysiological interaction analysis. This specific circuit, including hMT+/V5, putative V6 and medial cerebellum was activated for successful neurofeedback runs. The putamen and anterior insula were recruited for both successful and non-successful runs. Significance. Our findings indicate that hMT+/V5 is a region that can be modulated by focused imagery and that a specific cortico-cerebellar circuit is recruited during visual motion imagery leading to successful neurofeedback. These findings contribute to the debate on the relative potential of extrinsic (sensory) versus intrinsic (default-mode) brain regions in the clinical application of neurofeedback paradigms. This novel circuit might be a good target for future neurofeedback approaches that aim, for example, the training of focused attention in disorders such as ADHD.

Assessment of visual communication by information theory

Science.gov (United States)

Huck, Friedrich O.; Fales, Carl L.

1994-01-01

This assessment of visual communication integrates the optical design of the image-gathering device with the digital processing for image coding and restoration. Results show that informationally optimized image gathering ordinarily can be relied upon to maximize the information efficiency of decorrelated data and the visual quality of optimally restored images.

Visualizing turbulent mixing of gases and particles

Science.gov (United States)

Ma, Kwan-Liu; Smith, Philip J.; Jain, Sandeep

1995-01-01

A physical model and interactive computer graphics techniques have been developed for the visualization of the basic physical process of stochastic dispersion and mixing from steady-state CFD calculations. The mixing of massless particles and inertial particles is visualized by transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Groups of particles are traced through the vector field for the mean path as well as their statistical dispersion about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of particles in a turbulent environment are traced, not just mean paths. In combustion simulations of many industrial processes, good mixing is required to achieve a sufficient degree of combustion efficiency. The ability to visualize this multiphase mixing can not only help identify poor mixing but also explain the mechanism for poor mixing. The information gained from the visualization can be used to improve the overall combustion efficiency in utility boilers or propulsion devices. We have used this technique to visualize steady-state simulations of the combustion performance in several furnace designs.

Efficient estimators for likelihood ratio sensitivity indices of complex stochastic dynamics

Energy Technology Data Exchange (ETDEWEB)

Arampatzis, Georgios; Katsoulakis, Markos A.; Rey-Bellet, Luc [Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

2016-03-14

We demonstrate that centered likelihood ratio estimators for the sensitivity indices of complex stochastic dynamics are highly efficient with low, constant in time variance and consequently they are suitable for sensitivity analysis in long-time and steady-state regimes. These estimators rely on a new covariance formulation of the likelihood ratio that includes as a submatrix a Fisher information matrix for stochastic dynamics and can also be used for fast screening of insensitive parameters and parameter combinations. The proposed methods are applicable to broad classes of stochastic dynamics such as chemical reaction networks, Langevin-type equations and stochastic models in finance, including systems with a high dimensional parameter space and/or disparate decorrelation times between different observables. Furthermore, they are simple to implement as a standard observable in any existing simulation algorithm without additional modifications.

Chemical complexity induced by efficient ice evaporation in the Barnard 5 molecular cloud

Science.gov (United States)

Taquet, V.; Wirström, E. S.; Charnley, S. B.; Faure, A.; López-Sepulcre, A.; Persson, C. M.

2017-10-01

Cold gas-phase water has recently been detected in a cold dark cloud, Barnard 5 located in the Perseus complex, by targeting methanol peaks as signposts for ice mantle evaporation. Observed morphology and abundances of methanol and water are consistent with a transient non-thermal evaporation process only affecting the outermost ice mantle layers, possibly triggering a more complex chemistry. Here we present the detection of the complex organic molecules (COMs) acetaldehyde (CH3CHO) and methyl formate (CH3OCHO), as well as formic acid (HCOOH) and ketene (CH2CO), and the tentative detection of di-methyl ether (CH3OCH3) towards the "methanol hotspot" of Barnard 5 located between two dense cores using the single dish OSO 20 m, IRAM 30 m, and NRO 45 m telescopes. The high energy cis-conformer of formic acid is detected, suggesting that formic acid is mostly formed at the surface of interstellar grains and then evaporated. The detection of multiple transitions for each species allows us to constrain their abundances through LTE and non-LTE methods. All the considered COMs show similar abundances between 1 and 10% relative to methanol depending on the assumed excitation temperature. The non-detection of glycolaldehyde, an isomer of methyl formate, with a [glycolaldehyde]/[methyl formate] abundance ratio lower than 6%, favours gas phase formation pathways triggered by methanol evaporation. According to their excitation temperatures derived in massive hot cores, formic acid, ketene, and acetaldehyde have been designated as "lukewarm" COMs whereas methyl formate and di-methyl ether were defined as "warm" species. Comparison with previous observations of other types of sources confirms that lukewarm and warm COMs show similar abundances in low-density cold gas whereas the warm COMs tend to be more abundant than the lukewarm species in warm protostellar cores. This abundance evolution suggests either that warm COMs are indeed mostly formed in protostellar environments and

Juggling Efficiency

DEFF Research Database (Denmark)

Andersen, Rikke Sand; Vedsted, Peter

2015-01-01

on institutional logics, we illustrate how a logic of efficiency organise and give shape to healthcare seeking practices as they manifest in local clinical settings. Overall, patient concerns are reconfigured to fit the local clinical setting and healthcare professionals and patients are required to juggle...... efficiency in order to deal with uncertainties and meet more complex or unpredictable needs. Lastly, building on the empirical case of cancer diagnostics, we discuss the implications of the pervasiveness of the logic of efficiency in the clinical setting and argue that provision of medical care in today......'s primary care settings requires careful balancing of increasing demands of efficiency, greater complexity of biomedical knowledge and consideration for individual patient needs....

Visualization in medicine and life sciences

International Nuclear Information System (INIS)

Linsen, L.; Hamann, B.

2008-01-01

Visualization technology is becoming increasingly important for medical and biomedical data processing and analysis. This technology complements traditional image processing methods as it allows scientists to visually interact with large, high-resolution three-dimensional image data, for example. Furthermore, an ever increasing number of new data acquisition methods are being used in medicine and the life sciences, in particular in genomics and proteomics. This book discusses some of the latest visualization techniques and systems for effective analysis of such diverse, large, complex, and multi-source data. Experts from all over the world were invited to participate in a workshop held in July 2006 on the island Ruegen in Germany. About 40 participants presented state-of-the-art research on the topic. Research and survey papers have been solicited and carefully refereed, resulting in this collection. The topics covered include Segmentation and Feature Detection, Surface Extraction, Volume Visualization, Graph and Network Visualization, Visual Data Exploration, Multivariate and Multidimensional Data Visualization, Large Data Visualization. (orig.)

Integrated Data Visualization and Virtual Reality Tool

Science.gov (United States)

Dryer, David A.

1998-01-01

The Integrated Data Visualization and Virtual Reality Tool (IDVVRT) Phase II effort was for the design and development of an innovative Data Visualization Environment Tool (DVET) for NASA engineers and scientists, enabling them to visualize complex multidimensional and multivariate data in a virtual environment. The objectives of the project were to: (1) demonstrate the transfer and manipulation of standard engineering data in a virtual world; (2) demonstrate the effects of design and changes using finite element analysis tools; and (3) determine the training and engineering design and analysis effectiveness of the visualization system.

Creating visual explanations improves learning.

Science.gov (United States)

Bobek, Eliza; Tversky, Barbara

2016-01-01

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

Complex administrative procedures between administrative efficiency and the obligation to protect individual rights

International Nuclear Information System (INIS)

Steinberg, R.

1982-01-01

Due to their structural premise, administrative procedures possess an inordinate amount of influence, especially in complex situations of judicial decision making, to arrive at the ''right decision'' during the passing of binding regulatory ordinances. Since their system of organization is primarily subject to legislative influence, they are governed by the rules of administrative efficiency in the sense of extensive usage of performance - oriented governmental effectuation of constitutional rights. The demands for adequate judicial protection, of which wide administrative court procedure controls are part, will also serve the goal of reaching the ''right administrative decisions.'' (orig.) [de

Complex analysis of energy efficiency in operated high-rise residential building: Case study

Directory of Open Access Journals (Sweden)

Korniyenko Sergey

2018-01-01

Full Text Available Energy conservation and human thermal comfort enhancement in buildings is a topical issue of modern architecture and construction. The innovative solution of this problem makes it possible to enhance building ecological and maintenance safety, to reduce hydrocarbon fuel consumption, and to improve life standard of people. The requirements to increase of energy efficiency in buildings should be provided at all the stages of building's life cycle that is at the stage of design, construction and maintenance of buildings. The research purpose is complex analysis of energy efficiency in operated high-rise residential building. Many actions for building energy efficiency are realized according to the project; mainly it is the effective building envelope and engineering systems. Based on results of measurements the energy indicators of the building during annual period have been calculated. The main reason of increase in heat losses consists in the raised infiltration of external air in the building through a building envelope owing to the increased air permeability of windows and balcony doors (construction defects. Thermorenovation of the building based on ventilating and infiltration heat losses reduction through a building envelope allows reducing annual energy consumption. Energy efficiency assessment based on the total annual energy consumption of building, including energy indices for heating and a ventilation, hot water supply and electricity supply, in comparison with heating is more complete. The account of various components in building energy balance completely corresponds to modern direction of researches on energy conservation and thermal comfort enhancement in buildings.

Comparative study of the efficiency of complex formation and extraction of thorium by solutions of certain alkylaromatic α-hydroxy acids in heptanol

International Nuclear Information System (INIS)

Charykov, A.K.; Aleksandrova, E.A.; Vasil'eva, O.N.

1986-01-01

The constants for the extraction of thorium by solutions of alkylaromatic α-hydroxy acids in heptanol occur in the order log K/sub ex/ (hydroxydiphenylacetic acid) > log K/sub ex/ (phenoxyacetic acid) > log K/sub ex/ (hydroxyphenylacetic acid). For the example of extraction equilibria involving the participation of thorium carboxylate complexes an extraction efficiency parameter is introduced which enables the efficiency of extraction to be predicted on the basis of information on the formation constants of the neutral complexes and the dissociation constants of the extractant acids in the aqueous phase

Computerized diagnostic data analysis and 3-D visualization

International Nuclear Information System (INIS)

Schuhmann, D.; Haubner, M.; Krapichler, C.; Englmeier, K.H.; Seemann, M.; Schoepf, U.J.; Gebicke, K.; Reiser, M.

1998-01-01

Purpose: To survey methods for 3D data visualization and image analysis which can be used for computer based diagnostics. Material and methods: The methods available are explained in short terms and links to the literature are presented. Methods which allow basic manipulation of 3D data are windowing, rotation and clipping. More complex methods for visualization of 3D data are multiplanar reformation, volume projections (MIP, semi-transparent projections) and surface projections. Methods for image analysis comprise local data transformation (e.g. filtering) and definition and application of complex models (e.g. deformable models). Results: Volume projections produce an impression of the 3D data set without reducing the data amount. This supports the interpretation of the 3D data set and saves time in comparison to any investigation which requires examination of all slice images. More advanced techniques for visualization, e.g. surface projections and hybrid rendering visualize anatomical information to a very detailed extent, but both techniques require the segmentation of the structures of interest. Image analysis methods can be used to extract these structures (e.g. an organ) from the image data. Discussion: At the present time volume projections are robust and fast enough to be used routinely. Surface projections can be used to visualize complex and presegmented anatomical features. (orig.) [de

License plate localization in complex scenes based on oriented FAST and rotated BRIEF feature

Science.gov (United States)

Wang, Ran; Xia, Yuanchun; Wang, Guoyou; Tian, Jiangmin

2015-09-01

Within intelligent transportation systems, fast and robust license plate localization (LPL) in complex scenes is still a challenging task. Real-world scenes introduce complexities such as variation in license plate size and orientation, uneven illumination, background clutter, and nonplate objects. These complexities lead to poor performance using traditional LPL features, such as color, edge, and texture. Recently, state-of-the-art performance in LPL has been achieved by applying the scale invariant feature transform (SIFT) descriptor to LPL for visual matching. However, for applications that require fast processing, such as mobile phones, SIFT does not meet the efficiency requirement due to its relatively slow computational speed. To address this problem, a new approach for LPL, which uses the oriented FAST and rotated BRIEF (ORB) feature detector, is proposed. The feature extraction in ORB is much more efficient than in SIFT and is invariant to scale and grayscale as well as rotation changes, and hence is able to provide superior performance for LPL. The potential regions of a license plate are detected by considering spatial and color information simultaneously, which is different from previous approaches. The experimental results on a challenging dataset demonstrate the effectiveness and efficiency of the proposed method.

Evolutionary relevance facilitates visual information processing.

Science.gov (United States)

Jackson, Russell E; Calvillo, Dusti P

2013-11-03

Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search. Animacy is a significant component to evolutionary relevance of visual stimuli because perceiving animate entities is time-sensitive in ways that pose significant evolutionary consequences. Participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load. Evolutionarily novel and inanimate objects were located slowest and with the highest impact of perceptual load. Evolutionary relevance may importantly affect everyday visual information processing.

Interrelationships between trait anxiety, situational stress and mental effort predict phonological processing efficiency, but not effectiveness.

Science.gov (United States)

Edwards, Elizabeth J; Edwards, Mark S; Lyvers, Michael

2016-08-01

Attentional control theory (ACT) describes the mechanisms associated with the relationship between anxiety and cognitive performance. We investigated the relationship between cognitive trait anxiety, situational stress and mental effort on phonological performance using a simple (forward-) and complex (backward-) word span task. Ninety undergraduate students participated in the study. Predictor variables were cognitive trait anxiety, indexed using questionnaire scores; situational stress, manipulated using ego threat instructions; and perceived level of mental effort, measured using a visual analogue scale. Criterion variables (a) performance effectiveness (accuracy) and (b) processing efficiency (accuracy divided by response time) were analyzed in separate multiple moderated-regression analyses. The results revealed (a) no relationship between the predictors and performance effectiveness, and (b) a significant 3-way interaction on processing efficiency for both the simple and complex tasks, such that at higher effort, trait anxiety and situational stress did not predict processing efficiency, whereas at lower effort, higher trait anxiety was associated with lower efficiency at high situational stress, but not at low situational stress. Our results were in full support of the assumptions of ACT and implications for future research are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A model of primate visual cortex based on category-specific redundancies in natural images

Science.gov (United States)

Malmir, Mohsen; Shiry Ghidary, S.

2010-12-01

Neurophysiological and computational studies have proposed that properties of natural images have a prominent role in shaping selectivity of neurons in the visual cortex. An important property of natural images that has been studied extensively is the inherent redundancy in these images. In this paper, the concept of category-specific redundancies is introduced to describe the complex pattern of dependencies between responses of linear filters to natural images. It is proposed that structural similarities between images of different object categories result in dependencies between responses of linear filters in different spatial scales. It is also proposed that the brain gradually removes these dependencies in different areas of the ventral visual hierarchy to provide a more efficient representation of its sensory input. The authors proposed a model to remove these redundancies and trained it with a set of natural images using general learning rules that are developed to remove dependencies between responses of neighbouring neurons. Results of experiments demonstrate the close resemblance of neuronal selectivity between different layers of the model and their corresponding visual areas.

Advanced analysis of free visual exploration patterns in schizophrenia

Directory of Open Access Journals (Sweden)

Andreas eSprenger

2013-10-01

Full Text Available Background: Visual scanpath analyses provide important information about attention allocation and attention shifting during visual exploration of social situations. This study investigated whether patients with schizophrenia simply show restricted free visual exploration behaviour reflected by reduced saccade frequency and increased fixation duration or whether patients use qualitatively different exploration strategies than healthy controls. Methods: Scanpaths of 32 patients with schizophrenia and age-matched 33 healthy controls were assessed while participants freely explored six photos of daily life situations (20 seconds/photo evaluated for cognitive complexity and emotional strain. Using fixation and saccade parameters, we compared temporal changes in exploration behaviour, cluster analyses, attentional landscapes and analyses of scanpath similarities between both groups. Results: We found fewer fixation clusters, longer fixation durations within a cluster, fewer changes between clusters, and a greater increase of fixation duration over time in patients compared to controls. Scanpath patterns and attentional landscapes in patients also differed significantly from those of controls. Generally, cognitive complexity and emotional strain had significant effects on visual exploration behaviour. This effect was similar in both groups as were physical properties of fixation locations.Conclusions: Longer attention allocation to a given feature in a scene and less attention shifts in patients suggest a more focal processing mode compared to a more ambient exploration strategy in controls. These visual exploration alterations were present in patients independently of cognitive complexity, emotional strain or physical properties of visual cues implying that they represent a rather general deficit. Despite this impairment, patients were able to adapt their scanning behaviour to changes in cognitive complexity and emotional strain similar to controls.

Using Auditory Cues to Perceptually Extract Visual Data in Collaborative, Immersive Big-Data Display Systems

Science.gov (United States)

Lee, Wendy

The advent of multisensory display systems, such as virtual and augmented reality, has fostered a new relationship between humans and space. Not only can these systems mimic real-world environments, they have the ability to create a new space typology made solely of data. In these spaces, two-dimensional information is displayed in three dimensions, requiring human senses to be used to understand virtual, attention-based elements. Studies in the field of big data have predominately focused on visual representations and extractions of information with little focus on sounds. The goal of this research is to evaluate the most efficient methods of perceptually extracting visual data using auditory stimuli in immersive environments. Using Rensselaer's CRAIVE-Lab, a virtual reality space with 360-degree panorama visuals and an array of 128 loudspeakers, participants were asked questions based on complex visual displays using a variety of auditory cues ranging from sine tones to camera shutter sounds. Analysis of the speed and accuracy of participant responses revealed that auditory cues that were more favorable for localization and were positively perceived were best for data extraction and could help create more user-friendly systems in the future.

Electrophysiological evidence of altered visual processing in adults who experienced visual deprivation during infancy.

Science.gov (United States)

Segalowitz, Sidney J; Sternin, Avital; Lewis, Terri L; Dywan, Jane; Maurer, Daphne

2017-04-01

We examined the role of early visual input in visual system development by testing adults who had been born with dense bilateral cataracts that blocked all patterned visual input during infancy until the cataractous lenses were removed surgically and the eyes fitted with compensatory contact lenses. Patients viewed checkerboards and textures to explore early processing regions (V1, V2), Glass patterns to examine global form processing (V4), and moving stimuli to explore global motion processing (V5). Patients' ERPs differed from those of controls in that (1) the V1 component was much smaller for all but the simplest stimuli and (2) extrastriate components did not differentiate amongst texture stimuli, Glass patterns, or motion stimuli. The results indicate that early visual deprivation contributes to permanent abnormalities at early and mid levels of visual processing, consistent with enduring behavioral deficits in the ability to process complex textures, global form, and global motion. © 2017 Wiley Periodicals, Inc.

A method of reconstructing complex stratigraphic surfaces with multitype fault constraints

Science.gov (United States)

Deng, Shi-Wu; Jia, Yu; Yao, Xing-Miao; Liu, Zhi-Ning

2017-06-01

The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations (PDEs) is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between threedimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.

Characterization of Visual Scanning Patterns in Air Traffic Control.

Science.gov (United States)

McClung, Sarah N; Kang, Ziho

2016-01-01

Characterization of air traffic controllers' (ATCs') visual scanning strategies is a challenging issue due to the dynamic movement of multiple aircraft and increasing complexity of scanpaths (order of eye fixations and saccades) over time. Additionally, terminologies and methods are lacking to accurately characterize the eye tracking data into simplified visual scanning strategies linguistically expressed by ATCs. As an intermediate step to automate the characterization classification process, we (1) defined and developed new concepts to systematically filter complex visual scanpaths into simpler and more manageable forms and (2) developed procedures to map visual scanpaths with linguistic inputs to reduce the human judgement bias during interrater agreement. The developed concepts and procedures were applied to investigating the visual scanpaths of expert ATCs using scenarios with different aircraft congestion levels. Furthermore, oculomotor trends were analyzed to identify the influence of aircraft congestion on scan time and number of comparisons among aircraft. The findings show that (1) the scanpaths filtered at the highest intensity led to more consistent mapping with the ATCs' linguistic inputs, (2) the pattern classification occurrences differed between scenarios, and (3) increasing aircraft congestion caused increased scan times and aircraft pairwise comparisons. The results provide a foundation for better characterizing complex scanpaths in a dynamic task and automating the analysis process.

Fractal Analysis of Radiologists Visual Scanning Pattern in Screening Mammography

Energy Technology Data Exchange (ETDEWEB)

Alamudun, Folami T [ORNL; Yoon, Hong-Jun [ORNL; Hudson, Kathy [University of Tennessee, Knoxville (UTK); Morin-Ducote, Garnetta [University of Tennessee, Knoxville (UTK); Tourassi, Georgia [ORNL

2015-01-01

Several investigators have investigated radiologists visual scanning patterns with respect to features such as total time examining a case, time to initially hit true lesions, number of hits, etc. The purpose of this study was to examine the complexity of the radiologists visual scanning pattern when viewing 4-view mammographic cases, as they typically do in clinical practice. Gaze data were collected from 10 readers (3 breast imaging experts and 7 radiology residents) while reviewing 100 screening mammograms (24 normal, 26 benign, 50 malignant). The radiologists scanpaths across the 4 mammographic views were mapped to a single 2-D image plane. Then, fractal analysis was applied on the derived scanpaths using the box counting method. For each case, the complexity of each radiologist s scanpath was estimated using fractal dimension. The association between gaze complexity, case pathology, case density, and radiologist experience was evaluated using 3 factor fixed effects ANOVA. ANOVA showed that case pathology, breast density, and experience level are all independent predictors of the visual scanning pattern complexity. Visual scanning patterns are significantly different for benign and malignant cases than for normal cases as well as when breast parenchyma density changes.

Complex sparse spatial filter for decoding mixed frequency and phase coded steady-state visually evoked potentials.

Science.gov (United States)

Morikawa, Naoki; Tanaka, Toshihisa; Islam, Md Rabiul

2018-07-01

Mixed frequency and phase coding (FPC) can achieve the significant increase of the number of commands in steady-state visual evoked potential-based brain-computer interface (SSVEP-BCI). However, the inconsistent phases of the SSVEP over channels in a trial and the existence of non-contributing channels due to noise effects can decrease accurate detection of stimulus frequency. We propose a novel command detection method based on a complex sparse spatial filter (CSSF) by solving ℓ 1 - and ℓ 2,1 -regularization problems for a mixed-coded SSVEP-BCI. In particular, ℓ 2,1 -regularization (aka group sparsification) can lead to the rejection of electrodes that are not contributing to the SSVEP detection. A calibration data based canonical correlation analysis (CCA) and CSSF with ℓ 1 - and ℓ 2,1 -regularization cases were demonstrated for a 16-target stimuli with eleven subjects. The results of statistical test suggest that the proposed method with ℓ 1 - and ℓ 2,1 -regularization significantly achieved the highest ITR. The proposed approaches do not need any reference signals, automatically select prominent channels, and reduce the computational cost compared to the other mixed frequency-phase coding (FPC)-based BCIs. The experimental results suggested that the proposed method can be usable implementing BCI effectively with reduce visual fatigue. Copyright © 2018 Elsevier B.V. All rights reserved.

Advances in Multi-Sensor Scanning and Visualization of Complex Plants: the Utmost Case of a Reactor Building

Science.gov (United States)

Hullo, J.-F.; Thibault, G.; Boucheny, C.

2015-02-01

In a context of increased maintenance operations and workers generational renewal, a nuclear owner and operator like Electricité de France (EDF) is interested in the scaling up of tools and methods of "as-built virtual reality" for larger buildings and wider audiences. However, acquisition and sharing of as-built data on a large scale (large and complex multi-floored buildings) challenge current scientific and technical capacities. In this paper, we first present a state of the art of scanning tools and methods for industrial plants with very complex architecture. Then, we introduce the inner characteristics of the multi-sensor scanning and visualization of the interior of the most complex building of a power plant: a nuclear reactor building. We introduce several developments that made possible a first complete survey of such a large building, from acquisition, processing and fusion of multiple data sources (3D laser scans, total-station survey, RGB panoramic, 2D floor plans, 3D CAD as-built models). In addition, we present the concepts of a smart application developed for the painless exploration of the whole dataset. The goal of this application is to help professionals, unfamiliar with the manipulation of such datasets, to take into account spatial constraints induced by the building complexity while preparing maintenance operations. Finally, we discuss the main feedbacks of this large experiment, the remaining issues for the generalization of such large scale surveys and the future technical and scientific challenges in the field of industrial "virtual reality".

Vision and visual information processing in cubozoans

DEFF Research Database (Denmark)

Bielecki, Jan

relationship between acuity and light sensitivity. Animals have evolved a wide variety of solutions to this problem such as folded membranes, to have a larger receptive surfaces, and lenses, to focus light onto the receptive membranes. On the neural capacity side, complex eyes demand huge processing network...... animals in a wide range of behaviours. It is intuitive that a complex eye is energetically very costly, not only in components but also in neural involvement. The increasing behavioural demand added pressure on design specifications and eye evolution is considered an optimization of the inverse...... fit their need. Visual neuroethology integrates optics, sensory equipment, neural network and motor output to explain how animals can perform behaviour in response to a specific visual stimulus. In this doctoral thesis, I will elucidate the individual steps in a visual neuroethological pathway...

Storytelling and Visualization: An Extended Survey

Directory of Open Access Journals (Sweden)

Chao Tong

2018-03-01

Full Text Available Throughout history, storytelling has been an effective way of conveying information and knowledge. In the field of visualization, storytelling is rapidly gaining momentum and evolving cutting-edge techniques that enhance understanding. Many communities have commented on the importance of storytelling in data visualization. Storytellers tend to be integrating complex visualizations into their narratives in growing numbers. In this paper, we present a survey of storytelling literature in visualization and present an overview of the common and important elements in storytelling visualization. We also describe the challenges in this field as well as a novel classification of the literature on storytelling in visualization. Our classification scheme highlights the open and unsolved problems in this field as well as the more mature storytelling sub-fields. The benefits offer a concise overview and a starting point into this rapidly evolving research trend and provide a deeper understanding of this topic.

Why people see things that are not there: a novel Perception and Attention Deficit model for recurrent complex visual hallucinations.

Science.gov (United States)

Collerton, Daniel; Perry, Elaine; McKeith, Ian

2005-12-01

As many as two million people in the United Kingdom repeatedly see people, animals, and objects that have no objective reality. Hallucinations on the border of sleep, dementing illnesses, delirium, eye disease, and schizophrenia account for 90% of these. The remainder have rarer disorders. We review existing models of recurrent complex visual hallucinations (RCVH) in the awake person, including cortical irritation, cortical hyperexcitability and cortical release, top-down activation, misperception, dream intrusion, and interactive models. We provide evidence that these can neither fully account for the phenomenology of RCVH, nor for variations in the frequency of RCVH in different disorders. We propose a novel Perception and Attention Deficit (PAD) model for RCVH. A combination of impaired attentional binding and poor sensory activation of a correct proto-object, in conjunction with a relatively intact scene representation, bias perception to allow the intrusion of a hallucinatory proto-object into a scene perception. Incorporation of this image into a context-specific hallucinatory scene representation accounts for repetitive hallucinations. We suggest that these impairments are underpinned by disturbances in a lateral frontal cortex-ventral visual stream system. We show how the frequency of RCVH in different diseases is related to the coexistence of attentional and visual perceptual impairments; how attentional and perceptual processes can account for their phenomenology; and that diseases and other states with high rates of RCVH have cholinergic dysfunction in both frontal cortex and the ventral visual stream. Several tests of the model are indicated, together with a number of treatment options that it generates.

Evolutionary Relevance Facilitates Visual Information Processing

Directory of Open Access Journals (Sweden)

Russell E. Jackson

2013-07-01

Full Text Available Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search. Animacy is a significant component to evolutionary relevance of visual stimuli because perceiving animate entities is time-sensitive in ways that pose significant evolutionary consequences. Participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load. Evolutionarily novel and inanimate objects were located slowest and with the highest impact of perceptual load. Evolutionary relevance may importantly affect everyday visual information processing.

Loss of vision: imaging the visual pathways

International Nuclear Information System (INIS)

Jaeger, H.R.

2005-01-01

This is an overview of diseases presenting with visual impairment, which aims to provide an understanding of the anatomy and pathology of the visual pathways. It discusses the relevant clinical background and neuroimaging findings on CT and standard and advanced MRI of diseases affecting the globe; optic nerve/sheath complex; optic chiasm, tract and radiation; and visual cortex. The overview covers common tumours, trauma, inflammatory and vascular pathology, and conditions such as benign intracranial hypertension and posterior reversible leukoencephalopathy syndrome. (orig.)

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (11) Visualization Study on the Start-Up of the Steam Injector

International Nuclear Information System (INIS)

Koji Okamoto; Tadashi Narabayashi; Chikako Iwaki; Shuichi Ohmori; Michitsugu Mori

2006-01-01

The Steam Injector is the superior system to pump the fluid without rotating machine. Because the water column is surrounded by the saturated steam, very high heat transfer is also expected with direct condensation. The inside of the Steam Injector is very complicated. To improve the efficiency of the Steam Injector, the water column behavior inside the Injector is visualized using the Dynamic PIV system. Dynamic PIV system consists of the high-speed camera and lasers. In this study, 384 x 180 pixel resolution with 30,000 fps camera is used to visualize the flow. For the illumination CW green laser with 300 mW is applied. To view inside the Injector, relay lens system is set at the Injector wall. Very high speed water column during the starting up of Steam Injector had been clearly visualized with 30,000 fps. The wave velocity on the water column had been analyzed using PIV technique. The instability of the water column is also detected. (authors)

Implicit Learning of Complex Visual Contexts Under Non-Optimal Conditions

National Research Council Canada - National Science Library

Jiang, Yuhong V

2007-01-01

.... We can recognize an object or a face in a single glimpse and type 70 words per minute, yet we cannot hold more than a few objects at a time in visual working memory or split our attention to several locations...

Costs of storing colour and complex shape in visual working memory: Insights from pupil size and slow waves.

Science.gov (United States)

Kursawe, Michael A; Zimmer, Hubert D

2015-06-01

We investigated the impact of perceptual processing demands on visual working memory of coloured complex random polygons during change detection. Processing load was assessed by pupil size (Exp. 1) and additionally slow wave potentials (Exp. 2). Task difficulty was manipulated by presenting different set sizes (1, 2, 4 items) and by making different features (colour, shape, or both) task-relevant. Memory performance in the colour condition was better than in the shape and both condition which did not differ. Pupil dilation and the posterior N1 increased with set size independent of type of feature. In contrast, slow waves and a posterior P2 component showed set size effects but only if shape was task-relevant. In the colour condition slow waves did not vary with set size. We suggest that pupil size and N1 indicates different states of attentional effort corresponding to the number of presented items. In contrast, slow waves reflect processes related to encoding and maintenance strategies. The observation that their potentials vary with the type of feature (simple colour versus complex shape) indicates that perceptual complexity already influences encoding and storage and not only comparison of targets with memory entries at the moment of testing. Copyright © 2015 Elsevier B.V. All rights reserved.

Common neural substrates for visual working memory and attention.

Science.gov (United States)

Mayer, Jutta S; Bittner, Robert A; Nikolić, Danko; Bledowski, Christoph; Goebel, Rainer; Linden, David E J

2007-06-01

Humans are severely limited in their ability to memorize visual information over short periods of time. Selective attention has been implicated as a limiting factor. Here we used functional magnetic resonance imaging to test the hypothesis that this limitation is due to common neural resources shared by visual working memory (WM) and selective attention. We combined visual search and delayed discrimination of complex objects and independently modulated the demands on selective attention and WM encoding. Participants were presented with a search array and performed easy or difficult visual search in order to encode one or three complex objects into visual WM. Overlapping activation for attention-demanding visual search and WM encoding was observed in distributed posterior and frontal regions. In the right prefrontal cortex and bilateral insula blood oxygen-level-dependent activation additively increased with increased WM load and attentional demand. Conversely, several visual, parietal and premotor areas showed overlapping activation for the two task components and were severely reduced in their WM load response under the condition with high attentional demand. Regions in the left prefrontal cortex were selectively responsive to WM load. Areas selectively responsive to high attentional demand were found within the right prefrontal and bilateral occipital cortex. These results indicate that encoding into visual WM and visual selective attention require to a high degree access to common neural resources. We propose that competition for resources shared by visual attention and WM encoding can limit processing capabilities in distributed posterior brain regions.

Anatomical coupling between distinct metacognitive systems for memory and visual perception.

Science.gov (United States)

McCurdy, Li Yan; Maniscalco, Brian; Metcalfe, Janet; Liu, Ka Yuet; de Lange, Floris P; Lau, Hakwan

2013-01-30

A recent study found that, across individuals, gray matter volume in the frontal polar region was correlated with visual metacognition capacity (i.e., how well one's confidence ratings distinguish between correct and incorrect judgments). A question arises as to whether the putative metacognitive mechanisms in this region are also used in other metacognitive tasks involving, for example, memory. A novel psychophysical measure allowed us to assess metacognitive efficiency separately in a visual and a memory task, while taking variations in basic task performance capacity into account. We found that, across individuals, metacognitive efficiencies positively correlated between the two tasks. However, voxel-based morphometry analysis revealed distinct brain structures for the two kinds of metacognition. Replicating a previous finding, variation in visual metacognitive efficiency was correlated with volume of frontal polar regions. However, variation in memory metacognitive efficiency was correlated with volume of the precuneus. There was also a weak correlation between visual metacognitive efficiency and precuneus volume, which may account for the behavioral correlation between visual and memory metacognition (i.e., the precuneus may contain common mechanisms for both types of metacognition). However, we also found that gray matter volumes of the frontal polar and precuneus regions themselves correlated across individuals, and a formal model comparison analysis suggested that this structural covariation was sufficient to account for the behavioral correlation of metacognition in the two tasks. These results highlight the importance of the precuneus in higher-order memory processing and suggest that there may be functionally distinct metacognitive systems in the human brain.

Visual training paired with electrical stimulation of the basal forebrain improves orientation-selective visual acuity in the rat.

Science.gov (United States)

Kang, Jun Il; Groleau, Marianne; Dotigny, Florence; Giguère, Hugo; Vaucher, Elvire

2014-07-01

The cholinergic afferents from the basal forebrain to the primary visual cortex play a key role in visual attention and cortical plasticity. These afferent fibers modulate acute and long-term responses of visual neurons to specific stimuli. The present study evaluates whether this cholinergic modulation of visual neurons results in cortical activity and visual perception changes. Awake adult rats were exposed repeatedly for 2 weeks to an orientation-specific grating with or without coupling this visual stimulation to an electrical stimulation of the basal forebrain. The visual acuity, as measured using a visual water maze before and after the exposure to the orientation-specific grating, was increased in the group of trained rats with simultaneous basal forebrain/visual stimulation. The increase in visual acuity was not observed when visual training or basal forebrain stimulation was performed separately or when cholinergic fibers were selectively lesioned prior to the visual stimulation. The visual evoked potentials show a long-lasting increase in cortical reactivity of the primary visual cortex after coupled visual/cholinergic stimulation, as well as c-Fos immunoreactivity of both pyramidal and GABAergic interneuron. These findings demonstrate that when coupled with visual training, the cholinergic system improves visual performance for the trained orientation probably through enhancement of attentional processes and cortical plasticity in V1 related to the ratio of excitatory/inhibitory inputs. This study opens the possibility of establishing efficient rehabilitation strategies for facilitating visual capacity.

Evidence suggesting superiority of visual (verbal) vs. auditory test presentation modality in the P300-based, Complex Trial Protocol for concealed autobiographical memory detection.

Science.gov (United States)

Rosenfeld, J Peter; Ward, Anne; Frigo, Vincent; Drapekin, Jesse; Labkovsky, Elena

2015-04-01

One group of participants received a series of city name stimuli presented on trials of the Complex Trial Protocol (CTP) version of a P300-based, concealed information test (CIT). Stimuli were presented on alternating trials in either auditory or visual presentation modality. In 1/7 of the trials the participant's home town (probe) repeatedly appeared in a series of 6 other (irrelevant) repeated city names. In both modalities, probe stimuli produced larger P300s than irrelevant stimuli. Visual stimuli produced shorter behavioral reaction times and P300 latencies, as well as larger P300 probe amplitudes, probe-irrelevant amplitude differences, and individual diagnostic accuracies than the same stimuli presented in the auditory modality. Possible reasons for these effects are discussed, and subject to discussed limitations, the applied conclusion reached is that in all CITs, visual presentation of stimuli, if feasible, should be preferentially used. Copyright © 2015 Elsevier B.V. All rights reserved.

Immersive Visualization of the Solid Earth

Science.gov (United States)

Kreylos, O.; Kellogg, L. H.

2017-12-01

Immersive visualization using virtual reality (VR) display technology offers unique benefits for the visual analysis of complex three-dimensional data such as tomographic images of the mantle and higher-dimensional data such as computational geodynamics models of mantle convection or even planetary dynamos. Unlike "traditional" visualization, which has to project 3D scalar data or vectors onto a 2D screen for display, VR can display 3D data in a pseudo-holographic (head-tracked stereoscopic) form, and does therefore not suffer the distortions of relative positions, sizes, distances, and angles that are inherent in 2D projection and interfere with interpretation. As a result, researchers can apply their spatial reasoning skills to 3D data in the same way they can to real objects or environments, as well as to complex objects like vector fields. 3D Visualizer is an application to visualize 3D volumetric data, such as results from mantle convection simulations or seismic tomography reconstructions, using VR display technology and a strong focus on interactive exploration. Unlike other visualization software, 3D Visualizer does not present static visualizations, such as a set of cross-sections at pre-selected positions and orientations, but instead lets users ask questions of their data, for example by dragging a cross-section through the data's domain with their hands and seeing data mapped onto that cross-section in real time, or by touching a point inside the data domain, and immediately seeing an isosurface connecting all points having the same data value as the touched point. Combined with tools allowing 3D measurements of positions, distances, and angles, and with annotation tools that allow free-hand sketching directly in 3D data space, the outcome of using 3D Visualizer is not primarily a set of pictures, but derived data to be used for subsequent analysis. 3D Visualizer works best in virtual reality, either in high-end facility-scale environments such as CAVEs

Sodium Caseinate-Carrageenan Biopolymeric Nanocomplexes as a Carrier of Vitamin D: Study of Complex Formation, Particles Size and Encapsulation Efficiency

Directory of Open Access Journals (Sweden)

Maryam Khoshmanzar

2014-04-01

Full Text Available The protein-polysaccharide complex-based nanocapsule is one type of polymeric nanocarrier which can be potentially useful for encapsulation of hydrophobic nutraceuticals. In this research, caseinate-carrageenan complex was used for encapsulation of vitamin D. The complex formation between caseinate and carrageenan was carried out by lowering the pH under isoelectric point of protein. The Fourier transform infrared spectroscopy (FTIR and differential scanning colorimetry (DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of 1% caseinate particles was in the range of 150-300 nanometer and by addition of vitamin D the particle size increased to 450-750 nanometer. Moreover, carrageenan of all concentrations (at constant concentration of caseinate (1% and pH4.9 resulted in lower particle size below 100 nanometer. The stability of caseinate and its complex formation with carrageenan showed that encapsulation was achieved at 45% efficiency and also vitamin D stability (during 5 days storage was higher in nanocomplex compared to pure caseinate particles (60-63% compared to 53%. The complex formation between caseinate and carrageenan was carried out by pH decreasing under isoelectric point of protein. The FTIR and DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of caseinate 1% particles were in the range of 150 -300 nanometer and with adding vitamin D, particle size increased to 450-750 nanometer. Moreover, adding carrageenan at all used concentration (at constant concentration of caseinate (1% and pH4.9 resulted in reduced particle size to less than 100 nanometer and vitamin D stability (during 5 days storage was higher (60-63% in nanocomplex compared to pure caseinate particles (53%.The protein-polysaccharide complex based nanocapsule is one type of the polymeric nanocarriers which can potentially be used for encapsulation of hydrophobic nutraceuticals. In

A feast of visualization

Science.gov (United States)

2008-12-01

Strength through structure The visualization and assessment of inner human bone structures can provide better predictions of fracture risk due to osteoporosis. Using micro-computed tomography (µCT), Christoph Räth from the Max Planck Institute for Extraterrestrial Physics and colleagues based in Munich, Vienna and Salzburg have shown how complex lattice-shaped bone structures can be visualized. The structures were quantified by calculating certain "texture measures" that yield new information about the stability of the bone. A 3D visualization showing the variation with orientation of one of the texture measures for four different bone specimens (from left to right) is shown above. Such analyses may help us to improve our understanding of disease and drug-induced changes in bone structure (C Räth et al. 2008 New J. Phys. 10 125010).

End-User Development of Visualizations

DEFF Research Database (Denmark)

Lauesen, Søren; Pantazos, Kostas

2016-01-01

view. With uVis, developers construct a visualization from simple visual components such as boxes, curvePoints, and textboxes. All component properties such as Top and BackColor can be complex formulas similar to spreadsheet formulas. The operands in the formula can address relational data......In this article the authors investigated a visualization tool (uVis) for end-user developers, in order to see how end users actually use it. The tool was an early version and the investigation helped the authors to improve it. The investigation showed that users appreciated the simple formula...... language, the coordinated panels, and the drag-and-drop mechanism. However, the most important thing for them was the immediate response when they changed something, for instance part of a formula. The entire visualization was updated immediately without having to switch from development view to production...

Maximizing mutagenesis with solubilized CRISPR-Cas9 ribonucleoprotein complexes.

Science.gov (United States)

Burger, Alexa; Lindsay, Helen; Felker, Anastasia; Hess, Christopher; Anders, Carolin; Chiavacci, Elena; Zaugg, Jonas; Weber, Lukas M; Catena, Raul; Jinek, Martin; Robinson, Mark D; Mosimann, Christian

2016-06-01

CRISPR-Cas9 enables efficient sequence-specific mutagenesis for creating somatic or germline mutants of model organisms. Key constraints in vivo remain the expression and delivery of active Cas9-sgRNA ribonucleoprotein complexes (RNPs) with minimal toxicity, variable mutagenesis efficiencies depending on targeting sequence, and high mutation mosaicism. Here, we apply in vitro assembled, fluorescent Cas9-sgRNA RNPs in solubilizing salt solution to achieve maximal mutagenesis efficiency in zebrafish embryos. MiSeq-based sequence analysis of targeted loci in individual embryos using CrispRVariants, a customized software tool for mutagenesis quantification and visualization, reveals efficient bi-allelic mutagenesis that reaches saturation at several tested gene loci. Such virtually complete mutagenesis exposes loss-of-function phenotypes for candidate genes in somatic mutant embryos for subsequent generation of stable germline mutants. We further show that targeting of non-coding elements in gene regulatory regions using saturating mutagenesis uncovers functional control elements in transgenic reporters and endogenous genes in injected embryos. Our results establish that optimally solubilized, in vitro assembled fluorescent Cas9-sgRNA RNPs provide a reproducible reagent for direct and scalable loss-of-function studies and applications beyond zebrafish experiments that require maximal DNA cutting efficiency in vivo. © 2016. Published by The Company of Biologists Ltd.