Audio Classification from Time-Frequency Texture
Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.
Integrating visual information across camera movements with a visual-motor calibration map
Facing the competing demands for wider field of view and higher spatial resolution, computer vision will evolve toward greater use of foveal sensors and frequent camera movements. Integration of visual information across movements becomes a fundamental problem. We show that integration is possible using a biologically-inspired representation we call the visual-motor calibration map. The map is a memory-based model of the relationship between camera movements and corresponding pixel locations before and after any movement. The map constitutes a self-calibration that can compensate for non-uniform sampling, lens distortion, mechanical misalignments, and arbitrary pixel reordering. Integration takes place entirely in a retinotopic frame, using a short-term, predictive visual memory.
Collective form generation through visual participatory representation
In order to inspire and inform designers with the users data from participatory research, it may be important to represent data in a visual format that is easily understandable to the designers. For a case study in vehicle design, the paper outlines visual representation of data and the use of the same in the collective form generation session with a set of designers (vehicle design students) where designers use sketching as a tool to discuss, conceptualise and negotiate concepts towards the final vehicle form. Further, this paper attempts to demonstrate how deep and tacit context sensitive information from participatory research takes a form manifestation in collective form conceptualization by a set of designers.
We propose a two-stage learning method which implements occluded visual scene analysis into a generative model, a type of hierarchical neural network with bi-directional synaptic connections. Here, top-down connections simulate forward optics to generate predictions for sensory driven low-level representation, whereas bottom-up connections function to send the prediction error, the difference between the sensory based and the predicted low-level representation, to higher areas. The prediction error is then used to update the high-level representation to obtain better agreement with the visual scene. Although the actual forward optics is highly nonlinear and the accuracy of simulated forward optics is crucial for these types of models, the majority of previous studies have only investigated linear and simplified cases of forward optics. Here we take occluded vision as an example of nonlinear forward optics, where an object in front completely masks out the object behind. We propose a two-staged learning method inspired by the staged development of infant visual capacity. In the primary learning stage, a minimal set of object basis is acquired within a linear generative model using the conventional unsupervised learning scheme. In the secondary learning stage, an auxiliary multi-layer neural network is trained to acquire nonlinear forward optics by supervised learning. The important point is that the high-level representation of the linear generative model serves as the input and the sensory driven low-level representation provides the desired output. Numerical simulations show that occluded visual scene analysis can indeed be implemented by the proposed method. Furthermore, considering the format of input to the multi-layer network and analysis of hidden-layer units leads to the prediction that whole object representation of partially occluded objects, together with complex intermediate representation as a consequence of nonlinear transformation from non-occluded to occluded representation may exist in the low-level visual system of the brain. PMID:21094592
Cognitive Imaging in Visual Data-Driven Decision-Support Systems
Within data-driven types of decision-support systems (DDDSS, DSS), visual decision-support systems are those that try to inspire operator to find solution (decision) by producing visual representation of the data. Traditional approaches, that utilize traditional scientific visualization techniques such as 2D and 3D plots, vector fields, surface maps etc, works well when subject to represent is relatively simply structured data, low-dimensioned and weak interconnected. However, modern scientific experiments, as those in astrophysics observations, generate huge volumes of multidimensional complicated data. More sophisticated approach for visualizing of big volumes of multidimensional data is that based on the cognitive machine graphics techniques, which, for example, are used in visualization system Space Walker (SW). In contrast to illustrative ones, the cognitive images are aimed to make clear and evident some difficult scientific concepts and promote us with a new knowledge.
Biologically inspired task oriented gist model for scene classification
Capturing the scene gist is account for rapid and accurate scene classification in human visual system. This paper presents a biologically inspired task oriented gist model (BT-Gist) that attempts to emulate two important attributes of biological gist: holistic scene centered spatial layout representation and task oriented resolution determination. For the first attribute, we enrich the model of Oliva and Torralba by refining the low-level features in several biological plausible ways, extending the spatial layout to multiple resolution and followed by perceptually meaningful manifold analysis for a set of multi-resolution biologically inspired intrinsic manifold spatial layouts (BMSLs). Since the optimal resolution that best represents the spatial layout varies from task to task, we embod...
Intrinsic dimensionality predicts the saliency of natural dynamic scenes.
Since visual attention-based computer vision applications have gained popularity, ever more complex, biologically inspired models seem to be needed to predict salient locations (or interest points) in naturalistic scenes. In this paper, we explore how far one can go in predicting eye movements by using only basic signal processing, such as image representations derived from efficient coding principles, and machine learning. To this end, we gradually increase the complexity of a model from simple single-scale saliency maps computed on grayscale videos to spatiotemporal multiscale and multispectral representations. Using a large collection of eye movements on high-resolution videos, supervised learning techniques fine-tune the free parameters whose addition is inevitable with increasing complexity. The proposed model, although very simple, demonstrates significant improvement in predicting salient locations in naturalistic videos over four selected baseline models and two distinct data labeling scenarios. PMID:22516647
Translation-Invariant Representation for Cumulative Foot Pressure Images
Human can be distinguished by different limb movements and unique ground reaction force. Cumulative foot pressure image is a 2-D cumulative ground reaction force during one gait cycle. Although it contains pressure spatial distribution information and pressure temporal distribution information, it suffers from several problems including different shoes and noise, when putting it into practice as a new biometric for pedestrian identification. In this paper, we propose a hierarchical translation-invariant representation for cumulative foot pressure images, inspired by the success of Convolutional deep belief network for digital classification. Key contribution in our approach is discriminative hierarchical sparse coding scheme which helps to learn useful discriminative high-level visual features. Based on the feature representation of cumulative foot pressure images, we develop a pedestrian recognition system which is invariant to three different shoes and slight local shape change. Experiments are conducted on...
How to Evaluate Dimensionality Reduction? - Improving the Co-ranking Matrix
The growing number of dimensionality reduction methods available for data visualization has recently inspired the development of quality assessment measures, in order to evaluate the resulting low-dimensional representation independently from a methods' inherent criteria. Several (existing) quality measures can be (re)formulated based on the so-called co-ranking matrix, which subsumes all rank errors (i.e. differences between the ranking of distances from every point to all others, comparing the low-dimensional representation to the original data). The measures are often based on the partioning of the co-ranking matrix into 4 submatrices, divided at the K-th row and column, calculating a weighted combination of the sums of each submatrix. Hence, the evaluation process typically involves plotting a graph over several (or even all possible) settings of the parameter K. Considering simple artificial examples, we argue that this parameter controls two notions at once, that need not necessarily be combined, and th...
The State of the Art in Topology-Based Visualization of Unsteady Flow
Abstract Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analysing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available. We give an overview of previous research leading towards topology-based and topology-inspired visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, taking classical (i.e. steady) vector field topology as our starting point. Particularly, we focus on Lagrangian methods, space-time domain approaches, local methods and stochastic...
Active vision and image/video understanding systems for UGV based on network-symbolic models
Vision evolved as a sensory system for reaching, grasping and other motion activities. In advanced creatures, it has become a vital component of situation awareness, navigation and planning systems. Vision is part of a larger information system that converts visual information into knowledge structures. These structures drive the vision process, resolving ambiguity and uncertainty via feedback, and provide image understanding, that is an interpretation of visual information in terms of such knowledge models. It is hard to split such a system apart. Biologically inspired Network-Symbolic representation, where both systematic structural/logical methods and neural/statistical methods are parts of a single mechanism, is the most feasible for natural processing of visual information. It converts visual information into relational Network-Symbolic models, avoiding artificial precise computations of 3-dimensional models. Logic of visual scenes can be captured in such models and used for disambiguation of visual information. Network-Symbolic transformations derive abstract structures, which allows for invariant recognition of an object as exemplar of a class. Active vision helps create unambiguous network-symbolic models. This approach is consistent with NIST RCS. The UGV, equipped with such smart vision, will be able to plan path and navigate in a real environment, perceive and understand complex real-world situations and act accordingly.
Exact and approximate graph matching using random walks.
In this paper, we propose a general framework for graph matching which is suitable for different problems of pattern recognition. The pattern representation we assume is at the same time highly structured, like for classic syntactic and structural approaches, and of subsymbolic nature with real-valued features, like for connectionist and statistic approaches. We show that random walk based models, inspired by Google's PageRank, give rise to a spectral theory that nicely enhances the graph topological features at node level. As a straightforward consequence, we derive a polynomial algorithm for the classic graph isomorphism problem, under the restriction of dealing with Markovian spectrally distinguishable graphs (MSD), a class of graphs that does not seem to be easily reducible to others proposed in the literature. The experimental results that we found on different test-beds of the TC-15 graph database show that the defined MSD class "almost always" covers the database, and that the proposed algorithm is significantly more efficient than top scoring VF algorithm on the same data. Most interestingly, the proposed approach is very well-suited for dealing with partial and approximate graph matching problems, derived for instance from image retrieval tasks. We consider the objects of the COIL-100 visual collection and provide a graph-based representation, whose node's labels contain appropriate visual features. We show that the adoption of classic bipartite graph matching algorithms offers a straightforward generalization of the algorithm given for graph isomorphism and, finally, we report very promising experimental results on the COIL-100 visual collection. PMID:16013757
A Hierarchical Extension of the HOG Model Implemented in the Convolution-net for Human Detection
For the detection of generic objects in the field of image processing, histograms of orientation gradients (HOG) is discussed for these years. The performance of the classification system using HOG shows a good result. However, the performance of using HOG descriptor would be influenced by the detecting object size. In order to overcome this problem, we introduce a kind of hierarchy inspired from the convolution-net, which is a model of our visual processing system in the brain. The hierarchical HOG (H-HOG) integrates several scales of HOG descriptors in its architecture, and represents the input image as the combinatorial of more complex features rather than that of the orientation gradients. We investigate the H-HOG performance and compare with the conventional HOG. In the result, we obtain the better performance rather than the conventional HOG. Especially the size of representation dimension is much smaller than the conventional HOG without reducing the detecting performance.
STORM - A Novel Information Fusion and Cluster Interpretation Technique
Analysis of data without labels is commonly subject to scrutiny by unsupervised machine learning techniques. Such techniques provide more meaningful representations, useful for better understanding of a problem at hand, than by looking only at the data itself. Although abundant expert knowledge exists in many areas where unlabelled data is examined, such knowledge is rarely incorporated into automatic analysis. Incorporation of expert knowledge is frequently a matter of combining multiple data sources from disparate hypothetical spaces. In cases where such spaces belong to different data types, this task becomes even more challenging. In this paper we present a novel immune-inspired method that enables the fusion of such disparate types of data for a specific set of problems. We show that our method provides a better visual understanding of one hypothetical space with the help of data from another hypothetical space. We believe that our model has implications for the field of exploratory data analysis and kno...
Image/video understanding systems based on network-symbolic models and active vision
Vision is a part of information system that converts visual information into knowledge structures. These structures drive the vision process, resolving ambiguity and uncertainty via feedback, and provide image understanding, which is an interpretation of visual information in terms of these knowledge models. It is hard to split the entire system apart, and vision mechanisms cannot be completely understood separately from informational processes related to knowledge and intelligence. Brain reduces informational and computational complexities, using implicit symbolic coding of features, hierarchical compression, and selective processing of visual information. Vision is a component of situation awareness, motion and planning systems. Foveal vision provides semantic analysis, recognizing objects in the scene. Peripheral vision guides fovea to salient objects and provides scene context. Biologically inspired Network-Symbolic representation, in which both systematic structural/logical methods and neural/statistical methods are parts of a single mechanism, converts visual information into relational Network-Symbolic structures, avoiding precise artificial computations of 3-D models. Network-Symbolic transformations derive more abstract structures that allows for invariant recognition of an object as exemplar of a class and for a reliable identification even if the object is occluded. Systems with such smart vision will be able to navigate in real environment and understand real-world situations.
A fast biologically inspired algorithm for recurrent motion estimation.
We have previously developed a neurodynamical model of motion segregation in cortical visual area V1 and MT of the dorsal stream. The model explains how motion ambiguities caused by the motion aperture problem can be solved for coherently moving objects of arbitrary size by means of cortical mechanisms. The major bottleneck in the development of a reliable biologically inspired technical system with real-time motion analysis capabilities based on this neural model is the amount of memory necessary for the representation of neural activation in velocity space. We propose a sparse coding framework for neural motion activity patterns and suggest a means by which initial activities are detected efficiently. We realize neural mechanisms such as shunting inhibition and feedback modulation in the sparse framework to implement an efficient algorithmic version of our neural model of cortical motion segregation. We demonstrate that the algorithm behaves similarly to the original neural model and is able to extract image motion from real world image sequences. Our investigation transfers a neuroscience model of cortical motion computation to achieve technologically demanding constraints such as real-time performance and hardware implementation. In addition, the proposed biologically inspired algorithm provides a tool for modeling investigations to achieve acceptable simulation time. PMID:17170478
One of the crucial issues which often needs to be addressed in structural approaches to speech representation is the choice of fundamental symbolic units of representation. In this paper, a physiologically inspired methodology for defining these symbolic atomic units in terms of primitive articulato...
Using Description Logics for Recognising Textual Entailment
The aim of this paper is to show how we can handle the Recognising Textual Entailment (RTE) task by using Description Logics (DLs). To do this, we propose a representation of natural language semantics in DLs inspired by existing representations in first-order logic. But our most significant contrib...
As the first title in the new series, "New Directions in Communication Disorders Research: Integrative Approaches", this volume discusses a unique phenomenon in cognitive science, single-word reading, which is an essential element in successful reading competence. Single-word reading is an interdisciplinary area of research that incorporates phonological, orthographic, graphemic, and semantic information in the representations suitable for the task demands of reading. Editors Elena L. Grigorenko and Adam J. Naples have organized a collection of essays written by an outstanding group of scholars in order to systematically sample research on this important topic, as well as to describe the research within different experimental paradigms. "Single-Word Reading" provides an introduction to unfamiliar areas of research, and is an inspiration for future study. The introductory chapter sets up a contextual stage for connections between spoken and written word processing, the stage-based nature of their development, and the role of education. Succeeding chapters address visual word processing; the role of morphology in word recognition; the role of lexical representation; the biological bases of single-word reading and related processes; and more. Reading researchers will take interest in this substantial book, as will professionals and practitioners linked to the teaching of reading in the departments of school psychology, special education, communication disorders, neuroscience, cognitive science, linguistics, and reading. Contents of this book include: (1) Introduction (E.L. Grigorenko); (2) Continuity and Discontinuity in the Development of Single-Word Reading: Theoretical Speculations (P.H.K. Seymour); (3) The Visual Skill of "Reading" (T.A. Nazir, A. Huckauf); (4) The Development of Visual Expertise for Words: The Contribution of Electrophysiology (U. Maurer, B.D. McCandliss); (5) Phonological Representations for Reading Acquisition Across Languages (U. Goswami); (6) The Role of Morphology in Visual Word Recognition: Graded Semantic Influences Due to Competing Senses and Semantic Richness of the Stem (L.B. Feldman, D. Basnight-Brown); (7) Learning Words in Zekkish: Implications for Understanding Lexical Representation (L. Hart, C. Perfetti); (8) Cross-Code Consistency in a Functional Architecture for Word Recognition (J. Grainger, J.C. Ziegler); (9) Feedback Consistency Effects in Single-Word Reading (B. Kessler, R. Treiman, J. Mullennix); (10) Three Perspectives on Spelling Development (T.C. Pollo, R. Treiman, B. Kessler); (11) Comprehension of Single Words: The Role of Semantics in Word Identification and Reading Disability (J.M. Keenan, R.S. Betjemann); and (12) Single-Word Reading: Perspectives From Magnetic Source Imaging (P.G. Simos, R. Billingsley-Marshall, S. Sarkari, A.C. Papanicolaou). [Foreword by R. Paul.
Various papers on human vision, visual processing, and digital display are presented. The general topics considered include: physics and psychophysics of displayed information; visual performance and image quality; vision-based algorithms for image processing; visual sampling, compression, and representation; texture, pattern, and motion; color perception, coding, and representation. Some individual topics discussed are: respective fields and visual representations; psychophysical rating of image compression techniques; new paradigm for testing human and machine motion perception; motion perception model with interactions between spatial frequency channels; application of visual psychophysics to the design of video systems for use in space; unified model for human color perception and visual adaptation.
Tactical behavior of UGVs, which is needed for successful autonomous off-road driving, can be in many cases achieved by covering most possible driving situations with a set of rules and switching into a "drive-me-away" semi-autonomous mode when no such rule exists. However, the unpredictable and rapidly changing nature of combat situations requires more intelligent tactical behavior that must be based on predictive situation awareness with ongoing scene understanding and fast autonomous decision making. The implementation of image understanding and active vision is possible in the form of biologically inspired Network-Symbolic models, which combine the power of Computational Intelligence with graph and diagrammatic representation of knowledge. A Network-Symbolic system converts image information into an "understandable" Network-Symbolic format, which is similar to relational knowledge models. The traditional linear bottom-up "segmentation-grouping-learning-recognition" approach cannot provide a reliable separation of an object from its background/clutter, while human vision unambiguously solves this problem. An Image/Video Analysis that is based on Network-Symbolic approach is a combination of recursive hierarchical bottom-up and top-down processes. Logic of visual scenes can be captured in the Network-Symbolic models and used for the reliable disambiguation of visual information, including object detection and identification. Such a system can better interpret images/video for situation awareness, target recognition, navigation and actions and seamlessly integrates into 4D/RCS architecture.
Things to see and do: how scientific images work
Visual representations are an important and integral part of understanding and developing new scientific concepts – both in the laboratory and when engaging a public audience. Images often serve as the primary evidence supporting the claims of the scientific publication (Goodsell & Johnson, 2007). Fifty years ago Kendrew and Geis aimed for the best possible visual representation of myoglobin. Geis later emphasised: “We can only say 'it's something like that' – and only create a visual metaphor" (Paterlini, 2008). This chapter takes you through a series of visual representations made within a broad range of scientific areas, visual approaches and imaging technologies. It explores the way we look at scientific data, why some representations are better than others, and what you can do to achieve clarity, accuracy and aesthetic appearance in a visual representation that will represent your scientific data in the best possible way.
What your visual system sees where you are not looking
What is the representation in early vision? Considerable research has demonstrated that the representation is not equally faithful throughout the visual field; representation appears to be coarser in peripheral and unattended vision, perhaps as a strategy for dealing with an information bottleneck in visual processing. In the last few years, a convergence of evidence has suggested that in peripheral and unattended regions, the information available consists of local summary statistics. Given a rich set of these statistics, many attributes of a pattern may be perceived, yet precise location and configuration information is lost in favor of the statistical summary. This representation impacts a wide range of visual tasks, including peripheral identification, visual search, and visual cognition of complex displays. This paper discusses the implications for understanding visual perception, as well as for imaging applications such as information visualization.
Using Description Logics for Recognising Textual Entailment
The aim of this paper is to show how we can handle the Recognising Textual Entailment (RTE) task by using Description Logics (DLs). To do this, we propose a representation of natural language semantics in DLs inspired by existing representations in first-order logic. But our most significant contribution is the definition of two novel inference tasks: A-Box saturation and subgraph detection which are crucial for our approach to RTE.
Walking the Path—A New Journey to Explore and Discover through Visual Analytics
Visual representations are essential aids to human cognitive tasks and are valued to the extent that they provide stable and external reference points upon which dynamic activities and thought processes may be calibrated and upon which models and theories can be tested and confirmed. The active use and manipulation of visual representations makes many complex and intensive cognitive tasks feasible. As described in the recently published ''Illuminating the Path'', visual analytics is ''the science of analytical reasoning facilitated by interactive visual interfaces''. We describe research and development at PNNL focused on improving the value that interactive visual representations provide to persons engaged in complex cognitive tasks. We describe work at PNNL that carries forward research from multiple disciplines with a goal to improve the capability of visual representations and present examples whose aim is to improve the extraction, and reasoning about information, knowledge, and data.
McKay correspondence and the branching law for finite subgroups of $\\mathbf{SL}_3\\mathbb{C}$
Given $\\Gamma$ a finite subgroup of $\\mathbf{SL}_3\\mathbb{C}$, we determine how an arbitrary finite dimensional irreducible representation of $\\mathbf{SL}_3\\mathbb{C}$ decomposes under the action of $\\Gamma$. To the subgroup $\\Gamma$ we attach a generalized Cartan matrix $C_\\Gamma$. Then, inspired b...
Abstract: Recent literature has critiqued this notion of the 'tourist gaze' for reducing tourism to visual experiences 'sightseeing' and neglecting other senses and bodily experiences of doing tourism. A so-called 'performance turn' within tourist studies highlights how tourists experience places in more multi-sensuous ways, touching, tasting, smelling, hearing and so on, as well as the materiality of objects and not just objects as signs. With inspiration from Goffman's dramaturgical sociology and Nigel Thrift's non-representational theory, the performance turn employs performative metaphors to onceptualise the corporeality of tourist bodies and the embodied actions of and interactions between tourist workers, tourists and 'locals' on various stages. It has been suggested that it is necessary to choose between gazing and performing as the tourism paradigm (Perkin and Thorns 2001). Rather than defending the tourist gaze against this new performance turn, I rethink the concept of the tourist gaze as a performative and embodied practice and interaction by highlighting how each gaze depends on practices, interactions and material relations, as much as on discourses and signs. Through various ethnographic studies I spell out the embodied, hybridised, mobile and performative nature of tourist gazing especially with regard to tourist photography. The talk draws on my recent book Tourism, Performance and the Everyday: Consuming the Orient (Routledge, 2009, With M. Haldrup) and the substantially revised and expanded Tourist Gaze 3.0 that I am writing with John Urry at the moment.
Opposite Modulation of High- and Low-Level Visual Aftereffects by Perceptual Grouping
SummaryA fundamental task of visual perception is to group visual features-sometimes spatially separated and partially occluded-into coherent, unified representations of objects. Perceptual grouping can vastly simplify the description of a visual scene and is critical for our visual system to understand the three-dimensional visual world. Numerous neurophysiological and brain imaging studies have demonstrated that neural mechanisms of perceptual grouping are characterized by the enhancement of neural responses throughout the visual processing hierarchy, from lower visual areas processing grouped features to higher visual areas representing objects and shapes from grouping [1-3]. In a series of psychophysical adaptation experiments, we made the counterintuitive observation that perceptual g...
Visualization of Mined Pattern and Its Human Aspects
Researchers got success in mining the Web usage data effectively and efficiently. But representation of the mined patterns is often not in a form suitable for direct human consumption. Hence mechanisms and tools that can represent mined patterns in easily understandable format are utilized. Different techniques are used for pattern analysis, one of them is visualization. Visualization can provide valuable assistance for data analysis and decision making tasks. In the data visualization process, technical representations of web pages are replaced by user attractive text interpretations. Experiments with the real world problems showed that the visualization can significantly increase the quality and usefulness of web log mining results. However, how decision makers perceive and interact with a visual representation can strongly influence their understanding of the data as well as the usefulness of the visual presentation. Human factors therefore contribute significantly to the visualization process and should p...
SO(1,d+1) Racah coefficients: Type I Representations
We use AdS/CFT inspired methods to study the Lorentz group SO(1,d+1) Racah coefficients for type I representations. For such representations the Racah coefficient can be represented as an integral of a product of 6 bulk-to-bulk propagators over 4 copies of the hyperbolic space H_{d+1}. To compute the integrals we represent the bulk-to-bulk propagators in terms of bulk-to-boundary ones. The bulk integrals can be computed explicitly, and the boundary integrations are carried out by introducing Feynman parameters. The final result is an integral representation of the Racah coefficient given by 4 Barnes-Mellin type integrals.
The Use of Technology and Visualization in Calculus Instruction
This study was inspired by a history of student difficulties in calculus, and innovation in response to those difficulties. The goals of the study were fourfold. First, to design a mathlet for students to explore local linearity. Second, to redesign the curriculum of first semester calculus around the use of technology, an emphasis on visualization, and the use of local linearity to introduce the concept of the derivative, while delaying formal limits until later in the semester. Third, to design a framework to assess learning outcomes on the derivative. Fourth, to assess the impact of the course on the learning and attitudes of students. The study also aimed to assess the impact of learner characteristics, the role of technology, and the role of visualization, as they related to learning and attitude outcomes. The development and justification of the local linearity mathlet, the redesigned first semester calculus curriculum and the framework to assess derivative proficiency are reported. A mathlet is a computer application typically accessed over the internet which allows exploration of a specific mathematical concept. Students in this study developed a robust knowledge of the derivative as measured by the framework. Overall they demonstrated facility with stating definitions, finding the derivative and tangent lines, determining non-differentiability, and optimization. They demonstrated these proficiencies in multiple representations. Prior knowledge in rate and slope as well as proficiency translating between mathematical representations were significant determinants of eventual calculus proficiency. Spatial ability and prior knowledge of function were weaker predictors. There was clear evidence that the use of mathlets and graphs had a positive impact on student learning, and students were very positive about their use in this course. They experienced minimal changes in attitude regarding mathematics and technology in general, except for visually oriented students, who had very positive changes in attitude. The students in the experimental group were significantly more positive about their experiences using technology to learn calculus than students studying calculus with a traditional curriculum and labs using Maple which were not discussed in lecture. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.
Spatial orientations of visual word pairs to improve Bag-of-Visual-Words model
This paper presents a novel approach to incorporate spatial information in the bag-of-visual-words model for category level and scene classi?cation. In the traditional bag-of-visual-words model, feature vectors are histograms of visual words. This representation is appearance based and does not cont...
Voluntary head movement and allocentric perception of space
Although visual input is egocentric, some visual perceptions and representations may be allocentric, i.e., independent of the observer's vantage point or motion. By comparing the visual perception of 3D object motion during voluntary and involuntary motion in human subjects, results of three experim...
Representations in mental imagery and working memory: Evidence from different types of visual masks
Although few studies have systematically investigated the relationship between visual mental imagery and visual working memory, work on the effects of passive visual interference has generally demonstrated a dissociation between the two functions. In four experiments, we investigated a possible commonality between the two functions: We asked whether both rely on depictive representations. Participants judged the visual properties of letters using visual mental images or pictures of unfamiliar letters stored in short-term memory. Participants performed both tasks with two different types of interference: sequences of unstructured visual masks (consisting of randomly changing white and black dots) or sequences of structured visual masks (consisting of fragments of letters). The structured vi...
Kernel polynomial representation of imaginary-time Green's functions
Inspired by the recent proposed Legendre orthogonal polynomial representation of imaginary-time Green's functions, we develop an alternate representation for the Green's functions of quantum impurity models and combine it with the hybridization expansion continuous-time quantum Monte Carlo impurity solver. This representation is based on the kernel polynomial method, which introduces various integral kernels to filter fluctuations caused by the explicit truncations of polynomial expansion series and improve the computational precision significantly. As an illustration of the new representation, we reexamine the imaginary-time Green's functions of single-band Hubbard model in the framework of dynamical mean-field theory. The calculated results suggest that with carefully chosen integral kernels the Gibbs oscillations found in previous orthogonal polynomial representation have been suppressed vastly and remarkable corrections to the measured Green's functions have been obtained.
A novel gray image representation using overlapping rectangular NAM and extended shading approach
In this paper, inspired by the idea of overlapping rectangular region coding of binary images, we extend the SDS design, which is based on overlapping representation from binary images to gray images based on the non-symmetry and anti-packing model (NAM). A novel gray image representation is proposed by using the overlapping rectangular NAM (RNAM) and the extended Gouraud shading approach, which is called ORNAM representation. Also, we present an ORNAM representation algorithm of gray images. The encoding and the decoding of the proposed algorithm can be performed in O(n logn) time and O(n) time, respectively, where n denotes the number of pixels in a gray image. The wrong decoding problem of the hybrid matrix R for the overlapping RNAM representation of gray images is solved by using the ...
Understanding Visualization: A Formal Approach using Category Theory and Semiotics.
This article combines the vocabulary of semiotics and category theory to provide a formal analysis of visualization. It shows how familiar processes of visualization fit the semiotic frameworks of both Saussure and Peirce, and extends these structures using the tools of category theory to provide a general framework for understanding visualization in practice, including: relationships between systems, data collected from those systems, renderings of those data in the form of representations, the reading of those representations to create visualizations, and the use of those visualizations to create knowledge and understanding of the system under inspection. The resulting framework is validated by demonstrating how familiar information visualization concepts (such as literalness, sensitivity, redundancy, ambiguity, generalizability, and chart junk) arise naturally from it and can be defined formally and precisely. This article generalizes previous work on the formal characterization of visualization by, inter alia, Ziemkiewicz and Kosara and allows us to formally distinguish properties of the visualization process that previous work does not. PMID:23006838
The Trade-offs with Space Time Cube Representation of Spatiotemporal Patterns
Space time cube representation is an information visualization technique where spatiotemporal data points are mapped into a cube. Fast and correct analysis of such information is important in for instance geospatial and social visualization applications. Information visualization researchers have previously argued that space time cube representation is beneficial in revealing complex spatiotemporal patterns in a dataset to users. The argument is based on the fact that both time and spatial information are displayed simultaneously to users, an effect difficult to achieve in other representations. However, to our knowledge the actual usefulness of space time cube representation in conveying complex spatiotemporal patterns to users has not been empirically validated. To fill this gap we report on a between-subjects experiment comparing novice users error rates and response times when answering a set of questions using either space time cube or a baseline 2D representation. For some simple questions the error rat...
Design of virtual three-dimensional instruments for sound control
An environment for designing virtual instruments with 3D geometry has been prototyped and applied to real-time sound control and design. It enables a sound artist, musical performer or composer to design an instrument according to preferred or required gestural and musical constraints instead of constraints based only on physical laws as they apply to an instrument with a particular geometry. Sounds can be created, edited or performed in real-time by changing parameters like position, orientation and shape of a virtual 3D input device. The virtual instrument can only be perceived through a visualization and acoustic representation, or sonification, of the control surface. No haptic representation is available. This environment was implemented using CyberGloves, Polhemus sensors, an SGI Onyx and by extending a real- time, visual programming language called Max/FTS, which was originally designed for sound synthesis. The extension involves software objects that interface the sensors and software objects that compute human movement and virtual object features. Two pilot studies have been performed, involving virtual input devices with the behaviours of a rubber balloon and a rubber sheet for the control of sound spatialization and timbre parameters. Both manipulation and sonification methods affect the naturalness of the interaction. Informal evaluation showed that a sonification inspired by the physical world appears natural and effective. More research is required for a natural sonification of virtual input device features such as shape, taking into account possible co- articulation of these features. While both hands can be used for manipulation, left-hand-only interaction with a virtual instrument may be a useful replacement for and extension of the standard keyboard modulation wheel. More research is needed to identify and apply manipulation pragmatics and movement features, and to investigate how they are co-articulated, in the mapping of virtual object parameters. While the virtual instruments can be adapted to exploit many manipulation gestures, further work is required to reduce the need for technical expertise to realize adaptations. Better virtual object simulation techniques and faster sensor data acquisition will improve the performance of virtual instruments. The design environment which has been developed should prove useful as a (musical) instrument prototyping tool and as a tool for researching the optimal adaptation of machines to humans.
Locust System Integration into Demo Vechicles
This thesis project was carried out at Volvo Car Corporation. It is based on an EU project called Locust in which a bio-inspired visual sensor system (the Locust sensor system) for automotive collision avoidance was developed. The Locust sensor system is designed to emulate the collision avoidance f...
Applying Informatics Knowledge to Create 3D Worlds
Designing three-dimensional models using a tool like Google SketchUp is an attractive and inspiring activity fostering spatial thinking and visual creativity. The basic functions of SketchUp are easy to learn (low threshold). But more demanding design projects require computational thinking. This paper discusses some informatics concepts 3D-desigers need to know to be able to use SketchUp efficiently.
Design Democratization with Communities : Drawing Toward Locally Meaningful Design
We present a study on community drawing, a social activity aiming at meaningful representations and their recognition to inform locally valid design of mobile technologies. Furthermore, we investigate recognition within and across cultural borders, thereby exposing variances of localities. The study contributes to the still scarce body of empirical work on culturally meaningful development of visual representations and recognition, as part of a longitudinal research project in which we co-design a 3D visualization for a specific Namibian pilot site.
Three-dimensional display of document set
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional display of document set
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Photography as a Witness of Theatre La photographie comme témoin du théâtre
My paper investigates the meeting of theatre and photography in ‘theatre photography’. Recognizing that both art forms can determine theoretical and philosophical views on representation and self-representation, I aim to compare their visual strategies and the way they construct point of view. In th...
Some Basic Functions for Tree Representations of Bayesian Markov Chain Monte Carlo Clustering
The paper contains description of the implementation of C code for tree representation of Markov Chain Monte Carlo(MCMC) clustering. The aim of the code is to produce results which helps in visual representation of the most frequent pattern, its agglomerations and divisions and thus helps in constru...
Representation and visualization for heterogeneous CAD models
The representation and visualization scheme for heterogeneous CAD models are two key issues in heterogeneous object modeling, and are especially important to interactive heterogeneous CAD systems. In this paper, a hierarchical representation based on the Heterogeneous Feature Tree (HFT) structure is...
A Graphic Representation of States for Quantum Copying Machines
The aim of this paper is to introduce a new graphic representation of quantum states by means of a specific application: the analysis of two models of quantum copying machines. The graphic representation by diagrams of states o®ers a clear and detailed visualization of quantum information's flow dur...
Overview of EVE – the event visualization environment of ROOT
EVE is a high-level visualization library using ROOT's data-processing, GUI and OpenGL interfaces. It is designed as a framework for object management offering hierarchical data organization, object interaction and visualization via GUI and OpenGL representations. Automatic creation of 2D projected views is also supported. On the other hand, it can serve as an event visualization toolkit satisfying most HEP requirements: visualization of geometry, simulated and reconstructed data such as hits, clusters, tracks and calorimeter information. Special classes are available for visualization of raw-data. Object-interaction layer allows for easy selection and highlighting of objects and their derived representations (projections) across several views (3D, Rho-Z, R-Phi). Object-specific tooltips are provided in both GUI and GL views. The visual-configuration layer of EVE is built around a data-base of template objects that can be applied to specific instances of visualization objects to ensure consistent object prese...
Constructing visual tag dictionary by mining community-contributed media corpus
Visual-word based image representation has shown effectiveness in a wide variety of applications such as categorization, annotation and search. By detecting keypoints in images and treating their patterns as visual words, an image can be represented as a bag of visual words, which is analogous to the bag-of-words representation of text documents. In this paper, we construct a corpus named visual tag dictionary by mining community-contributed media corpus. Unlike the conventional dictionaries that define terms with textual words, the visual tag dictionary interprets each tag with visual words. The dictionary is constructed in a fully automatic way by exploring community-contributed images and their associated tags. With this dictionary, tags and images are connected via visual words and man...
A visualization model based on the mathematics of fiber bundles
In this report, we describe a visualization model based on the mathematics of fiber bundles. In a companion report (SAND 88-8972), we introduced the visualization management system (ViMS), a new approach to the development of software for visualization in scientific computing (ViSC). A visualization management system implements a visualization model which specifies the class of geometric objects, the graphic representations of the objects and the operations provided by the system. In the model described here, the geometric objects are sections of fiber bundles. We give a brief, intuitive description of the mathematics of fiber bundles, emphasizing aspects relevant to our visualization model. We describe three important classes of operations on fiber bundles. We develop a flexible scheme for constructing graphic representations of fiber bundles and a simple but useful visualization taxonomy. 7 refs., 5 figs., 1 tab.
"Parallel" transport - revisited
Parallel transport in a fibre bundle with respect to smooth paths in the base space B have recently been extended to representations of the smooth singular simplicial set Sing_{smooth}(B). Inspired by these extensions,I revisit the development of a notion of `parallel' transport in the topological setting of fibrations with the homotopy lifting property and then extend it to representations of Sing(B) on such fibrations. Closely related is the notion of (strong or `infty') homotopy action, which has variants under a variety of names.
China and Colette Brunschwig-s Art of Witnessing
Abstract Steven Shankman discusses the genesis of a remarkable and singular work, influenced by calligraphy and traditional Chinese art, which today forms part of national French collections (Centre Georges Pompidou and the Muse d-art moderne, Paris). Hidden during the Second World War by a friend who introduced her to traditional Chinese art, Colette Brunschwig was seduced by the practice of calligraphy, the -interiority- of painting liberated from the notion of representation, and by -le vide la source de l-inspiration-, in the words of Marinette Bruno. The work of Emmanuel Levinas, particularly his theory that the truth of testimony is not the truth of representation, guides Shankman-s thinking throughout the article.
The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H_2, Banach spaces, covariant functional calculus and many others. Keywords: Wavelets, coherent states, group representations, Hardy space, functional calculus, Berezin calculus, Radon transform, Moebius map, maximal function, affine group, special linear group, numerical range, characteristic function, functional model.
Automatic speech emotion recognition using modulation spectral features
In this study, modulation spectral features (MSFs) are proposed for the automatic recognition of human affective information from speech. The features are extracted from an auditory-inspired long-term spectro-temporal representation. Obtained using an auditory filterbank and a modulation filterbank for speech analysis, the representation captures both acoustic frequency and temporal modulation frequency components, thereby conveying information that is important for human speech perception but missing from conventional short-term spectral features. On an experiment assessing classification of discrete emotion categories, the MSFs show promising performance in comparison with features that are based on mel-frequency cepstral coefficients and perceptual linear prediction coefficients, two co...
Intelligent systems: A semiotic perspective. Volume I: Theoretical semiotics
This report contains the papers from the Proceedings of the 1996 International Multidisciplinary Conference - Theoretical Semiotics. General topics covered are: semiotic in biology: biologically inspired complex systems; intelligence in constructed complex systems; intelligence of learning and evolution; fuzzy logic and the mechanisms of generalization; information representation for decision making; sematic foundations; syntactics of intelligent systems: the kind of logic available; intelligence of recognition: the semiotic tools; and multiresolutional methods.
Emerging Materiality : Reflections on creative use of software in electronic music composition
The authors examine how materiality emerges from complex chains of mediation in creative software use. The primarily theoretical argument is inspired and illustrated by interviews with two composers of electronic music. The authors argue that computer mediated activity should not primarily be understood in terms of simple mediation, but rather as chains of complex mediation in which the dominant form of representation is metonymy rather than metaphor.
Solving quantum master equations in phase space by continued-fraction methods
Inspired on the continued-fraction technique to solve the classical Fokker--Planck equation, we develop continued-fraction methods to solve quantum master equations in phase space (Wigner representation of the density matrix). The approach allows to study several classes of nonlinear quantum systems subjected to environmental effects (fluctuations and dissipation), with the only limitations that the starting master equations may have. We illustrate the method with the canonical problem of quantum Brownian motion in periodic potentials.
Visual Mining of Epidemic Networks
We show how an interactive graph visualization method based on maximal modularity clustering can be used to explore a large epidemic network. The visual representation is used to display statistical tests results that expose the relations between the propagation of HIV in a sexual contact network and the sexual orientation of the patients.
The N170 is an occipito-temporal visual event-related potential that is larger in response to faces than other nonface object categories and has been associated with the early activation of visual face representations in the human brain. It has been recently showed that spatially misaligning the bot...
Attentional load modulates responses of human primary visual cortex to invisible stimuli
Visual neuroscience has long sought to determine the extent to which stimulus-evoked activity in visual cortex depends on attention and awareness. Some influential theories of consciousness maintain that the allocation of attention is restricted to conscious representations [1, 2]. However, in the l...
Neural Mechanisms of Short-term Plasticity in the Human Visual System.
Following circumscribed retinal damage, extensive reorganization of topographically organized visual cortical areas has been demonstrated in several species of mammals (including humans). Although reorganization is often studied over extended time scales, neural response properties change within seconds of retinal deafferentation. Understanding the mechanisms underlying these short-term effects is essential for developing a complete picture of representational plasticity. One approach to the study of short-term plasticity has been to use an artificial scotoma, a stimulus-induced analog of a retinal scotoma, as a model. Here, we use event-related potentials in an artificial scotoma paradigm to examine 2 aspects of short-term plasticity in the human visual system. First, we investigated the changes within visual representations temporarily deprived of patterned visual input by probing the inner boundaries of an artificial scotoma. We found an enhanced early sensory P1, consistent with a reduction in inhibition (disinhibition), a proposed mechanism of short-term visual plasticity. Second, we investigated mechanisms through which representations of surrounding space invade a visually deprived area by probing the outer boundaries of an artificial scotoma. In this case, a later visual component, the N1, was enhanced, suggesting that feedback may provide a source of unmasked, or invading, activity to visually deprived representations. PMID:22235030
Graphical Visualization in the Knowledge Management System Atanor
The interaction between a knowledge management systems and the users requires well-adapted visualization tools with graphical formalization of knowledge. The formalization is often theoretically based on graph-models. Yet, the best associated visual representations use trees but may be more limited ...
Opposite modulation of high- and low-level visual aftereffects by perceptual grouping.
A fundamental task of visual perception is to group visual features - sometimes spatially separated and partially occluded - into coherent, unified representations of objects. Perceptual grouping can vastly simplify the description of a visual scene and is critical for our visual system to understand the three-dimensional visual world. Numerous neurophysiological and brain imaging studies have demonstrated that neural mechanisms of perceptual grouping are characterized by the enhancement of neural responses throughout the visual processing hierarchy, from lower visual areas processing grouped features to higher visual areas representing objects and shapes from grouping. In a series of psychophysical adaptation experiments, we made the counterintuitive observation that perceptual grouping amplified the shape aftereffect but meanwhile, reduced the tilt aftereffect and the threshold elevation aftereffect (TEAE). Furthermore, the modulation of perceptual grouping on the TEAE showed a partial interocular transfer. This finding suggests a 2-fold effect of perceptual grouping - enhancing the high-level shape representation and attenuating the low-level feature representation even at a monocular level. We propose that this effect is a functional manifestation of a predictive coding scheme and reflects an efficient code of visual information across lower and higher visual cortical areas. PMID:22578417
Skeleton Modulated Topological Perception Map for Rapid Viewpoint Selection
Incorporating insights from human visual perception into 3D object processing has become an important research field in computer graphics during the past decades. Many computational models for different applications have been proposed, such as mesh saliency, mesh roughness and mesh skeleton. In this letter, we present a novel Skeleton Modulated Topological Visual Perception Map (SMTPM) integrated with visual attention and visual masking mechanism. A new skeletonisation map is presented and used to modulate the weight of saliency and roughness. Inspired by salient viewpoint selection, a new Loop subdivision stencil decision based rapid viewpoint selection algorithm using our new visual perception is also proposed. Experimental results show that the SMTPM scheme can capture more richer visual perception information and our rapid viewpoint selection achieves high efficiency.
DEVELOPING AN UNDERSTANDING OF IONS IN JUNIOR SECONDARY SCHOOL CHEMISTRY
There is growing research interest in the challenges and opportunities learners face in representing scientific understandings, processes and reasoning. These challenges include integrating verbal, visual and mathematical modes in science discourse to make strong conceptual links between representations and classroom experiences. Our paper reports on a project that aimed to identify practical and theoretical issues entailed in a representation-intensive approach to guiding students? conceptual learning in science. We focus here on a teacher developing students? understanding of the formation of ions and molecules. We argue that the representations produced by students in this process met the criteria for representational competence proposed by diSessa (Cognition and Instruction, 22, 293?33...
Visual modelling electrochemical processes
Visual modelling assumes a graphic form of model description and visual representation of research results. The main element of modelling system representation is a block diagram. Owing to appearance of this line of investigation (<<object-oriented modelling>>) a software was produced (for example, Simulink in MatLab). The examples of ordinary differential equations solving schemes for initial stage discharge of lead-acid battery positive electrode visual modelling are presented. The comparative analysis of two algorithms (a shooting method and algorithm similar to back propagation algorithm used in the neural networks theory) also is carried out. (author)
Scientific knowledge is constructed and communicated through a range of forms in addition to verbal language. Maps, graphs, charts, diagrams, formulae, models, and drawings are just some of the ways in which science concepts can be represented. Representational competence---an aspect of visual literacy that focuses on the ability to interpret, transform, and produce visual representations---is a key component of science literacy and an essential part of science reading and writing. To date, however, most research has examined learning from representations rather than learning with representations. This dissertation consisted of three distinct projects that were related by a common focus on learning from visual representations as an important aspect of scientific literacy. The first project was the development of an exploratory framework that is proposed for use in investigations of students constructing and interpreting multimedia texts. The exploratory framework, which integrates cognition, metacognition, semiotics, and systemic functional linguistics, could eventually result in a model that might be used to guide classroom practice, leading to improved visual literacy, better comprehension of science concepts, and enhanced science literacy because it emphasizes distinct aspects of learning with representations that can be addressed though explicit instruction. The second project was a metasynthesis of the research that was previously conducted as part of the Explicit Literacy Instruction Embedded in Middle School Science project (Pacific CRYSTAL, http://www.educ.uvic.ca/pacificcrystal). Five overarching themes emerged from this case-to-case synthesis: the engaging and effective nature of multimedia genres, opportunities for differentiated instruction using multimodal strategies, opportunities for assessment, an emphasis on visual representations, and the robustness of some multimodal literacy strategies across content areas. The third project was a mixed-methods verification study that was conducted to refine and validate the theoretical framework. This study examined middle school students' representational competence and focused on students' creation of visual representations such as labelled diagrams, a form of representation commonly found in science information texts and textbooks. An analysis of the 31 Grade 6 participants' representations and semistructured interviews revealed five themes, each of which supports one or more dimensions of the exploratory framework: participants' use of color, participants' choice of representation (form and function), participants' method of planning for representing, participants' knowledge of conventions, and participants' selection of information to represent. Together, the results of these three projects highlight the need for further research on learning with rather than learning from representations.
Benefitting InfoVis with visual difficulties.
Many well-cited theories for visualization design state that a visual representation should be optimized for quick and immediate interpretation by a user. Distracting elements like decorative "chartjunk" or extraneous information are avoided so as not to slow comprehension. Yet several recent studies in visualization research provide evidence that non-efficient visual elements may benefit comprehension and recall on the part of users. Similarly, findings from studies related to learning from visual displays in various subfields of psychology suggest that introducing cognitive difficulties to visualization interaction can improve a user's understanding of important information. In this paper, we synthesize empirical results from cross-disciplinary research on visual information representations, providing a counterpoint to efficiency-based design theory with guidelines that describe how visual difficulties can be introduced to benefit comprehension and recall. We identify conditions under which the application of visual difficulties is appropriate based on underlying factors in visualization interaction like active processing and engagement. We characterize effective graph design as a trade-off between efficiency and learning difficulties in order to provide Information Visualization (InfoVis) researchers and practitioners with a framework for organizing explorations of graphs for which comprehension and recall are crucial. We identify implications of this view for the design and evaluation of information visualizations. PMID:22034340
Visual field representation in the newborn rabbit's cortex.
The representation of the visual field in the newborn rabbit's visual cortex appears on about the 10th day after the animal's birth coinciding with the time of its eye opening. Initially the visual response is obtained from a small anterolateral segment of the visual area of the cortex representing a few degrees of the extreme nasal vision of the animal. Even at this early stage, the visually responsive area of the rabbit's cortex seems to organize into V1 and V2 with the binocular response confined to V1 only. By the 15th day after the animal's birth, the visually responsive area in the newborn rabbit extends medially and posteriorly over the cortex, representing more of the animal's temporal and superior visual fields. By this time the binocular response is established over a narrow zone of the animal's visual cortex, representing a few degrees of the nasal visual field, on either side of the boundary between V1 and V2. Between the 16th and 17th day after the rabbit's birth, the cortical representation of the animal's visual field extends medially to the margin of the fissura sagittalis lateralis and caudally to the posterior pole of the hemisphere. In this visually responsive area of the cortex, the band-shaped visual field of the newborn rabbit is asymmetrically represented. PMID:679049
Visual pattern mining in histology image collections using bag of features
Objective: The paper addresses the problem of finding visual patterns in histology image collections. In particular, it proposes a method for correlating basic visual patterns with high-level concepts combining an appropriate image collection representation with state-of-the-art machine learning techniques. Methodology: The proposed method starts by representing the visual content of the collection using a bag-of-features strategy. Then, two main visual mining tasks are performed: finding associations between visual-patterns and high-level concepts, and performing automatic image annotation. Associations are found using minimum-redundancy-maximum-relevance feature selection and co-clustering analysis. Annotation is done by applying a support-vector-machine classifier. Additionally, the pro...
A visualization model based on the mathematics of fiber bundles
In this paper, a visualization model based on the mathematics of fiber bundles is described. A brief, intuitive description of the mathematics of fiber bundles is given, introducing the concepts using typical application examples and emphasizing aspects relevant to our visualization model. Three important classes of operations on fiber bundles are described. A flexible scheme is developed for constructing graphic representations of fiber bundles and a simple but useful visualization taxonomy.
AER synthetic generation in hardware for bio-inspired spiking systems
Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems it is absolutely necessary to have a computer interface that allows (a) to read AER interchip traffic into the computer and visualize it on screen, and (b) convert conventional frame-based video stream in the computer into AER and inject it at some point of the AER structure. This is necessary for test and debugging of complex AER systems. This paper addresses the problem of converting, in a computer, a conventional frame-based video stream into the spike event based representation AER. There exist several proposed software methods for synthetic generation of AER for bio-inspired systems. This paper presents a hardware implementation for one method, which is based on Linear-Feedback-Shift-Register (LFSR) pseudo-random number generation. The sequence of events generated by this hardware, which follows a Poisson distribution like a biological neuron, has been reconstructed using two AER integrator cells. The error of reconstruction for a set of images that produces different traffic loads of event in the AER bus is used as evaluation criteria. A VHDL description of the method, that includes the Xilinx PCI Core, has been implemented and tested using a general purpose PCI-AER board. This PCI-AER board has been developed by authors, and uses a Spartan II 200 FPGA. This system for AER Synthetic Generation is capable of transforming frames of 64x64 pixels, received through a standard computer PCI bus, at a frame rate of 25 frames per second, producing spike events at a peak rate of 107 events per second.
A Novel Visual Speech Representation and HMM Classification for Visual Speech Recognition
This paper presents the development of a novel visual speech recognition (VSR) system based on a new representation that extends the standard viseme concept (that is referred in this paper to as Visual Speech Unit (VSU)) and Hidden Markov Models (HMM). Visemes have been regarded as the smallest visual speech elements in the visual domain and they have been widely applied to model the visual speech, but it is worth noting that they are problematic when applied to the continuous visual speech recognition. To circumvent the problems associated with standard visemes, we propose a new visual speech representation that includes not only the data associated with the articulation of the visemes but also the transitory information between consecutive visemes. To fully evaluate the appropriateness of the proposed visual speech representation, in this paper an extensive set of experiments have been conducted to analyse the performance of the visual speech units when compared with that offered by the standard MPEG-4 visemes. The experimental results indicate that the developed VSR application achieved up to 90% correct recognition when the system has been applied to the identification of 60 classes of VSUs, while the recognition rate for the standard set of MPEG-4 visemes was only in the range 62-72%.
Visualization rhetoric: framing effects in narrative visualization.
Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation. PMID:22034342
An Experiment on Graph Analysis Methodologies for Scenarios
Visual graph representations are increasingly used to represent, display, and explore scenarios and the structure of organizations. The graph representations of scenarios are readily understood, and commercial software is available to create and manage these representations. The purpose of the research presented in this paper is to explore whether these graph representations support quantitative assessments of the underlying scenarios. The underlying structure of the scenarios is the information that is being targeted in the experiment and the extent to which the scenarios are similar in content. An experiment was designed that incorporated both the contents of the scenarios and analysts’ graph representations of the scenarios. The scenarios’ content was represented graphically by analysts, and both the structure and the semantics of the graph representation were attempted to be used to understand the content. The structure information was not found to be discriminating for the content of the scenarios in this experiment; but, the semantic information was discriminating.
We examined the organization and function of the ventral object processing pathway. The prevailing theoretical approach in this field holds that the ventral object processing stream has a modular organization, in which visual perception is carried out in posterior regions and visual memory is carried out, independently, in the anterior temporal lobe. In contrast, recent work has argued against this modular framework, favoring instead a continuous, hierarchical account of cognitive processing in these regions. We join the latter group and illustrate our view with simulations from a computational model that extends the perceptual-mnemonic feature-conjunction model of visual discrimination proposed by Bussey and Saksida [Bussey, T. J., & Saksida, L. M. "The organization of visual object representations: A connectionist model of effects of lesions in perirhinal cortex." "European Journal of Neuroscience, 15," 355-364, 2002]. We use the extended model to revisit early data from Iwai and Mishkin [Iwai, E., & Mishkin, M. "Two visual foci in the temporal lobe of monkeys." In N. Yoshii & N. Buchwald (Eds.), "Neurophysiological basis of learning and behavior" (pp. 1-11). Japan: Osaka University Press, 1968]; this seminal study was interpreted as evidence for the modularity of visual perception and visual memory. The model accounts for a double dissociation in monkeys' visual discrimination performance following lesions to different regions of the ventral visual stream. This double dissociation is frequently cited as evidence for separate systems for perception and memory. However, the model provides a parsimonious, mechanistic, single-system account of the double dissociation data. We propose that the effects of lesions in ventral visual stream on visual discrimination are due to compromised representations within a hierarchical representational continuum rather than impairment in a specific type of learning, memory, or perception. We argue that consideration of the nature of stimulus representations and their processing in cortex is a more fruitful approach than attempting to map cognition onto functional modules.
Synchronized views for exploring populations of neurons
Davis (Data Viewing System) is a general-purpose data viewer designed for the simultaneous display of a large number of dynamic data sets. Davis was inspired by the need to explore computational models of the cerebral cortex. These systems are distinguished by complex dynamic elements interconnected in irregular patterns. Neuroscientists study the detailed behavior of individual elements and how these elements interact to achieve cortical function. This paper describes Davis and its use in cortical visualization. Davis is written in Java and can be run from a browser or as a standalone application. Users must provide an XML description of their data, which Davis uses for its menus, browsing and visualization. Davis visualizations can be applied to any collection of space-time data sets, and the Davis infrastructure allows visualizations to be added easily. Davis handles the synchronization of different visualizations and encapsulates different threading policies.
CityGML - Interoperable semantic 3D city models
CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations.This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its relationship to other standards from the fields of computer graphics and computer-aided architectural design and to the prospective INSPIRE model are discussed, as well as the impact CityGML has and is having on the software industry, on applications of 3D city models, and on science generally.
Three modes of experimentation with art and ethnography
Whilst the Writing culture critique since the mid-1980s has led to a number of experiments with ethnographic writing, the visual side has been neglected. Thus this article argues that by looking at the work of Oppitz, Downey, and Lockhart, which has not been considered in the canon of visual and general anthropology, anthropologists can develop new strategies of visual representation and research in regard to (1) conceptualizing closeness to and distance from the ethnographic subject, (2) the multiple positioning of the participant observer, and (3) developing new formal possibilities of visual representation. In doing so, anthropologists can start to address the unfulfilled potential of visual experimentation inherent in the Writing culture critique. This article then discusses three exam...
Fifty years ago, Serge Moscovici first outlined a theory of social representations. In this article, we attempt to discuss and to contextualize research that has been inspired by this original impetus from the particular angle of its relevance to political psychology. We argue that four defining components of social representations need to be taken into account, and that these elements need to be articulated with insights from the social identity tradition about the centrality of self and group constructions in order to develop original insights into political psychological phenomena. First, social representations are shared knowledge, and the way interpretations of the world are collectively elaborated is critical to the way people are able to act within the world. Second, social represen...
Auditory-inspired sparse representation of audio signals
This article deals with the generation of auditory-inspired spectro-temporal features aimed at audio coding. To do so, we first generate sparse audio representations we call spikegrams, using projections on gammatone/gammachirp kernels that generate neural spikes. Unlike Fourier-based representations, these representations are powerful at identifying auditory events, such as onsets, offsets, transients, and harmonic structures. We show that the introduction of adaptiveness in the selection of gammachirp kernels enhances the compression rate compared to the case where the kernels are non-adaptive. We also integrate a masking model that helps reduce bitrate without loss of perceptible audio quality. We finally propose a method to extract frequent audio objects (patterns) in the aforementione...
Structured cognition and neural systems: From rats to language
Much of animal and human cognition is compositional in nature: higher order, complex representations are formed by (rule-governed) combination of more primitive representations. We review here some of the evidence for compositionality in perception and memory, motivating an approach that takes ideas and techniques from computational linguistics to model aspects of structural representation in cognition. We summarize some recent developments in our work that, on the one hand, use algorithms from computational linguistics to model memory consolidation and the formation of semantic memory, and on the other hand use insights from the neurobiology of memory to develop a neurally inspired model of syntactic parsing that improves over existing (not cognitively motivated) models in computational l...
Developing an Understanding of Ions in Junior Secondary School Chemistry
There is growing research interest in the challenges and opportunities learners face in representing scientific understandings, processes and reasoning. These challenges include integrating verbal, visual and mathematical modes in science discourse to make strong conceptual links between representations and classroom experiences. Our paper reports on a project that aimed to identify practical and theoretical issues entailed in a representation-intensive approach to guiding students' conceptual learning in science. We focus here on a teacher developing students' understanding of the formation of ions and molecules. We argue that the representations produced by students in this process met the criteria for representational competence proposed by diSessa ("Cognition and Instruction," 22, 293-331, 2004) and Kozma & Russell (2005). The students understood that an effective representation needed to show relevant information, focus on pertinent points, be self-sufficient in its claims about the topic and provide coherent links between different parts of the representation. The final activity showed that their representations reached Kozma & Russell's (2005) highest level of competence, where the students were able to use specific features of their representations to critique their suitability for explaining bonding and were able to show how their representation linked to the periodic table as a representation. We conclude by considering the implications of these findings.
Two cerebral blood volume (CBV)-weighted fMRI techniques, gray matter nulled (GMN) and vascular space occupancy (VASO)-dependent techniques at spatial resolution of 2x2x5mm^3, were compared in the study investigating functional responses in the human visual cortex to stimulation in normoxia (inspired O2=21%) and mild hypoxic hypoxia (inspired O2=12%). GMN and VASO signals and T2* were quantified in activated voxels. While the CBV-weighted signal changes in voxels activated by visual stimulation were similar in amplitude in both fMRI techniques in both oxygenation conditions, the number of activated voxels during hypoxic hypoxia was significantly reduced by 72+/-22% in GMN fMRI and 66+/-23% in VASO fMRI. T2* prolonged in GMN and VASO activated voxels in normoxia by 1.6+/-0.5ms and 1.7+/-0.5...
Bird song: in vivo, in vitro, in silico
Bird song, long since an inspiration for artists, writers and poets also poses challenges for scientists interested in dissecting the mechanisms underlying the neural, motor, learning and behavioral systems behind the beak and brain, as a way to recreate and synthesize it. We use a combination of quantitative visualization experiments with physical models and computational theories to understand the simplest aspects of these complex musical boxes, focusing on using the controllable elastohydrodynamic interactions to mimic aural gestures and simple songs.
This workshop paper explores the Web 2.0 journey of the MLC Libraries' teacher-librarians, librarian, library and audio visual technicians. Our journey was initially inspired by Will Richardson and supported by the School Library Association of Victoria (SLAV) Web 2.0 professional development program. The 12 week technological skills program "23 things" assisted in motivating the MLC Libraries' team to adopt Web 2.0 technologies into their daily work with students and staff.
This publication aims to inspire and challenge to: 1) transform energy technology to architectural potentials, 2) introduce visions about daylight's potential into the energy debate, and 3) develop new strategies for interdisciplinary collaboration. In addition to converting solar energy to electricity transparent solar cells can be integrated into glass facades and thereby regulate indoor climate and daylight intake. Furthermore solar cells can contribute new visual dimensions. (BA)
CT scans of the hypopharynx and larynx during inspiration, expiration, breath holding and phonation
CT scans of the hypopharynx and larynx during inspiration, expiration, breath holding and phonation of the letter E were performed on seven volunteers. Two mm contiguous scans were obtained to span the glottis and supraglottic area. The vocal cords were shown in the paramedian or median position on breath holding and phonation. The ditails of the arytenoid cartilages were better visualized with thin slices. The laryngeal ventricles were demonstrable on phonation scans.
Jim Thomas, a visionary scientist and inspirational leader, died on 6 August 2010 in Richland, Washington. His impact on the fields of computer graphics, user interface software, and visualization was extraordinary, his ability to personally change people’s lives even more so. He is remembered for his enthusiasm, his mentorship, his generosity, and, most of all, his laughter. This collection of remembrances images him through the eyes of his many friends.
COMODI: On the Graphical User Interface
We propose a series of features for the graphical user interface (GUI) of the COmputational MOdule Integrator (COMODI) \\cite{Synasc05a}\\cite{COMODI}. In view of the special requirements that a COMODI type of framework for scientific computing imposes and inspiring from existing solutions that provide advanced graphical visual programming environments, we identify those elements and associated behaviors that will have to find their way into the first release of COMODI.
The representation modification hypothesis of perceptual learning attributes the practice-induced improvements in sensitivity and/or discriminability to changes in the early visual areas. We used motion aftereffects (MAE) to probe the representations of motion direction. In two experiments, four practice sessions on a fine direction-discrimination task caused large stimulus-specific improvements in d' but no significant stimulus-specific changes in either static or dynamic MAE duration at posttest relative to a pretest. Power analysis indicated that the data were approximately 100 times more likely given the hypothesis of no MAE change than the hypothesis of a 10% relative change. In light of converging evidence in the MAE literature, this suggests that little or no change occurred in the cortical representations of visual motion up to and including area MT. The task specificity of the learning effect challenges the representation modification hypothesis and supports an alternative-selective reweighting. PMID:21856327
The effect of irrelevant visual input on working memory for sign language.
We report results showing that working memory for American Sign Language (ASL) is sensitive to irrelevant signed input (and other structured visual input) in a manner similar to the effects of irrelevant auditory input on working memory for speech. Deaf signers were disrupted on serial recall of lists of ASL signs when either pseudosigns or moving shapes were presented during a retention interval. Hearing subjects asked to recall lists of printed English words did not show disruption under the same interference conditions. The results favor models that hypothesize modality-specific representations of language within working memory, as opposed to amodal representations. The results further indicate that working memory for sign language involves visual or quasi-visual representations, suggesting parallels to visuospatial working memory. PMID:15448060
Visualization and analysis of classifiers performance in multi-class medical data
The primary role of the thyroid gland is to help regulation of the body's metabolism. The correct diagnosis of thyroid dysfunctions is very important and early diagnosis is the key factor in its successful treatment. In this article, we used four different kinds of classifiers, namely Bayesian, k-NN, k-Means and 2-D SOM to classify the thyroid gland data set. The robustness of classifiers with regard to sampling variations is examined using a cross validation method and the performance of classifiers in medical diagnostic is visualized by using cobweb representation. The cobweb representation is the original contribution of this work to visualize the classifiers performance when the data have more than two classes. This representation is a newly used method to visualize the classifiers per...
Covert reading of letters in a case of global alexia
This study describes the case of a global alexic patient with a severe reading deficit affecting words, letters and Arabic numbers, following a left posterior lesion. The patient (VA) could not match spoken letters to their graphic form. A preserved ability to recognize shape and canonical orientation of letters indicates intact access to the representation of letters and numbers as visual objects. A relatively preserved ability to match lowercase to uppercase letters suggests partially spared access to abstract letter identities independently of their visual forms. The patient was also unable to match spoken letters and numbers to their visual form, indicating that she could not access the graphemic representations of letters from their phonological representations. This pattern of perfor...
Auditory Responsive Naming versus Visual Confrontation Naming in Dementia
Dysnomia is typically assessed during neuropsychological evaluation through visual confrontation naming. Responsive naming to description, however, has been shown to have a more distributed representation in both fMRI and cortical stimulation studies. While naming deficits are common in dementia, the relative sensitivity of visual confrontation versus auditory responsive naming has not been directly investigated. The current study compared visual confrontation naming and auditory responsive naming in a dementia sample of mixed etiologies to examine patterns of performance across these naming tasks. A total of 50 patients with dementia of various etiologies were administered visual confrontation naming and auditory responsive naming tasks using stimuli that were matched in overall word freq...
Exploitation of natural geometrical regularities facilitates target detection
We have evolved to operate within a dynamic visual world in which natural visual signals are not random but have various statistical regularities. Our rich experience of the probability structure of these regularities could influence visual computation. Considering that spatiotemporal regularity, co-linearity and co-circularity are common geometrical regularities in natural scenes, we explored how our visual system exploits these regularities to achieve accurate and efficient representations of the external world. By measuring human contrast detection performance of a briefly presented foveal target embedded in dynamic stimulus sequences (comprising six short bars appearing consecutively towards the fovea) imitating common regularity structures, we found that both contrast sensitivity and ...
Toward a Visually-Oriented School Mathematics Curriculum
What does it mean to have a visual representation of a mathematical object, concept, or process? What visualization strategies support growth in mathematical thinking, reasoning, generalization, and knowledge? Is mathematical seeing culture-free? And how can information drawn from studies in blind subjects help us understand the significance of a multimodal approach to learning mathematics? "Toward a Visually-Oriented School Mathematics Curriculum" explores a unified theory of visualization in school mathematical learning via the notion of progressive modeling. Based on the author's
Augmented Segmentation and Visualization for Presentation Videos
We investigate methods of segmenting, visualizing, and indexing presentation videos by separately considering audio and visual data. The audio track is segmented by speaker, and augmented with key phrases which are extracted using an Automatic Speech Recognizer (ASR). The video track is segmented by visual dissimilarities and augmented by representative key frames. An interactive user interface combines a visual representation of audio, video, text, and key frames, and allows the user to navigate a presentation video. We also explore clustering and labeling of speaker data and present preliminary results.
The purpose of this study was to investigate students' use of visual imagery and its relationship to spatial visualization ability while solving mathematical word problems. Students with learning disabilities (LD), average achievers, and gifted students in sixth grade (N = 66) participated in this study. Students were assessed on measures of mathematical problem solving, visual imagery representation, and spatial visualization ability. The results indicated that gifted students performed better on both spatial visualization measures than students with LD and average-achieving students. Use of visual images was positively correlated with higher mathematical word-problem-solving performance. Furthermore, the use of schematic imagery was significantly and positively correlated with higher performance on each spatial visualization measure; conversely, it was negatively correlated with the use of pictorial images. PMID:17165617
Invariant Visual Object and Face Recognition: Neural and Computational Bases, and a Model, VisNet.
Neurophysiological evidence for invariant representations of objects and faces in the primate inferior temporal visual cortex is described. Then a computational approach to how invariant representations are formed in the brain is described that builds on the neurophysiology. A feature hierarchy model in which invariant representations can be built by self-organizing learning based on the temporal and spatial statistics of the visual input produced by objects as they transform in the world is described. VisNet can use temporal continuity in an associative synaptic learning rule with a short-term memory trace, and/or it can use spatial continuity in continuous spatial transformation learning which does not require a temporal trace. The model of visual processing in the ventral cortical stream can build representations of objects that are invariant with respect to translation, view, size, and also lighting. The model has been extended to provide an account of invariant representations in the dorsal visual system of the global motion produced by objects such as looming, rotation, and object-based movement. The model has been extended to incorporate top-down feedback connections to model the control of attention by biased competition in, for example, spatial and object search tasks. The approach has also been extended to account for how the visual system can select single objects in complex visual scenes, and how multiple objects can be represented in a scene. The approach has also been extended to provide, with an additional layer, for the development of representations of spatial scenes of the type found in the hippocampus. PMID:22723777
Rats in Alberta: looking at pest-control posters from the 1950s.
How did the rat-control program, launched by the Government of Alberta in 1950, become associated with the identity and heritage of the province? The authors answer this question by undertaking close visual analyses of the anti-rat posters and pamphlets that were distributed by the government throughout the 1950s. Using a visual methodology inspired by semiotics, they argue that the early rat-control program ambitiously promoted Alberta as a unified, clean province that was both distinct from its prairie neighbours and for the most part populated with vigilant, hardworking citizens eager to remove unwanted intruders. PMID:22145175
Real-Time Cognitive Computing Architecture for Data Fusion in a Dynamic Environment
A novel cognitive computing architecture is conceptualized for processing multiple channels of multi-modal sensory data streams simultaneously, and fusing the information in real time to generate intelligent reaction sequences. This unique architecture is capable of assimilating parallel data streams that could be analog, digital, synchronous/asynchronous, and could be programmed to act as a knowledge synthesizer and/or an "intelligent perception" processor. In this architecture, the bio-inspired models of visual pathway and olfactory receptor processing are combined as processing components, to achieve the composite function of "searching for a source of food while avoiding the predator." The architecture is particularly suited for scene analysis from visual data and odorant.
Visual short-term memory: activity supporting encoding and maintenance in retinotopic visual cortex.
Recent studies have demonstrated that retinotopic cortex maintains information about visual stimuli during retention intervals. However, the process by which transient stimulus-evoked sensory responses are transformed into enduring memory representations is unknown. Here, using fMRI and short-term visual memory tasks optimized for univariate and multivariate analysis approaches, we report differential involvement of human retinotopic areas during memory encoding of the low-level visual feature orientation. All visual areas show weaker responses when memory encoding processes are interrupted, possibly due to effects in orientation-sensitive primary visual cortex (V1) propagating across extrastriate areas. Furthermore, intermediate areas in both dorsal (V3a/b) and ventral (LO1/2) streams are significantly more active during memory encoding compared with non-memory (active and passive) processing of the same stimulus material. These effects in intermediate visual cortex are also observed during memory encoding of a different stimulus feature (spatial frequency), suggesting that these areas are involved in encoding processes on a higher level of representation. Using pattern-classification techniques to probe the representational content in visual cortex during delay periods, we further demonstrate that simply initiating memory encoding is not sufficient to produce long-lasting memory traces. Rather, active maintenance appears to underlie the observed memory-specific patterns of information in retinotopic cortex. PMID:22776452
Clonal selection: an immunological algorithm for global optimization over continuous spaces
In this research paper we present an immunological algorithm (IA) to solve global numerical optimization problems for high-dimensional instances. Such optimization problems are a crucial component for many real-world applications. We designed two versions of the IA: the first based on binary-code representation and the second based on real values, called opt-IMMALG01 and opt-IMMALG, respectively. A large set of experiments is presented to evaluate the effectiveness of the two proposed versions of IA. Both opt-IMMALG01 and opt-IMMALG were extensively compared against several nature inspired methodologies including a set of Differential Evolution algorithms whose performance is known to be superior to many other bio-inspired and deterministic algorithms on the same test bed. Also hybrid and ...
Hierarchical Classifiers for Robust Topological Robot Localization
This paper presents a novel appearance-based technique for topological robot localization and place recognition. A vocabulary of visual words is formed automatically, representing local features that frequently occur in the set of training images. Using the vocabulary, a spatial pyramid representation is built for each image by repeatedly subdividing it and computing histograms of visual words at increasingly fine resolutions. An information maximization technique is then applied to build a hierarchical classifier for each class by learning informative features. While top-level features in the hierarchy are selected from the coarsest resolution of the representation, capturing the holistic statistical properties of the images, child features are selected from finer resolutions, encoding mo...
Perceptual load influences auditory space perception in the ventriloquist aftereffect
A period of exposure to trains of simultaneous but spatially offset auditory and visual stimuli can induce a temporary shift in the perception of sound location. This phenomenon, known as the `ventriloquist aftereffect', reflects a realignment of auditory and visual spatial representations such that they approach perceptual alignment despite their physical spatial discordance. Such dynamic changes to sensory representations are likely to underlie the brain's ability to accommodate inter-sensory discordance produced by sensory errors (particularly in sound localization) and variability in sensory transduction. It is currently unknown, however, whether these plastic changes induced by adaptation to spatially disparate inputs occurs automatically or whether they are dependent on selectively a...
Prepared or not prepared: Top-down modulation on memory of features and feature bindings
Orienting attention to the to-be-tested representations can enhance representations and protect them from interference. Previous studies have found that this effect on feature and bound representations was comparable despite their difference in stability. This may have occurred because participants were tested in a block design, which is susceptible to participants' effective top-down control on the cued representations based on the predictability of the design. In this study, we investigated how the foreknowledge of when and what to expect would affect visual representations in a change-detection task. Cue onset time was either early or late; changes included either features or feature bindings. When predictability was maximized via a block design (Experiments 1, 5, and 6), early cues equ...
SNARC Hunting: Examining Number Representation in Deaf Students
Many deaf children and adults show lags in mathematical abilities. The current study examines the basic number representations that allow individuals to perform higher-level arithmetical procedures. These representations are normally present in the earliest stages of development, but they may be affected by cultural, developmental, and educational factors. Deaf and hearing participants were asked to perform two number comparison tasks. Analysis of response times revealed that all participants showed effects normally associated with representation of magnitude on a visual-analog mental number line: SNARC, distance, and size effects. However, deaf participants were slower overall in making comparative judgements, suggesting that whilst their numerical representation does not differ from that of hearing individuals, the efficiency with which they process basic numerical information is lower. The results are discussed in terms of interactions between biologically determined numerical representations and cultural and schooling factors that differentially affect deaf and hearing individuals.
Visual memory transformations in dyslexia.
Representational Momentum refers to observers' distortion of recognition memory for pictures that imply motion because of an automatic mental process which extrapolates along the implied trajectory of the picture. Neuroimaging evidence suggests that activity in the magnocellular visual pathway is necessary for representational momentum to occur. It has been proposed that individuals with dyslexia have a magnocellular deficit, so it was hypothesised that these individuals would show reduced or absent representational momentum. In this study, 30 adults with dyslexia and 30 age-matched controls were compared on two tasks, one linear and one rotation, which had previously elicited the representational momentum effect. Analysis indicated significant differences in the performance of the two groups, with the dyslexia group having a reduced susceptibility to representational momentum in both linear and rotational directions. The findings highlight that deficits in temporal spatial processing may contribute to the perceptual profile of dyslexia. PMID:17688144
Constraints of Perception and Cognition in Relativistic Physics
This article explores the constraints of perception and cognition in relativistic physics. Describing reality as a cognitive representation of our sensory inputs, the article shows how the limitations in perception translate to the properties of space and time in physics. This framework of looking at the visual reality as our brain's representation limited by the speed of light unifies and explains a wide array of seemingly unrelated astrophysical and cosmological phenomena. Understanding the constraints on our space and time due to the limitations in perception and cognitive representation opens the possibility of understanding astrophysics and cosmology from a whole new viewpoint.
Geometric Algebra Model of Distributed Representations
Formalism based on GA is an alternative to distributed representation models developed so far --- Smolensky's tensor product, Holographic Reduced Representations (HRR) and Binary Spatter Code (BSC). Convolutions are replaced by geometric products, interpretable in terms of geometry which seems to be the most natural language for visualization of higher concepts. This paper recalls the main ideas behind the GA model and investigates recognition test results using both inner product and a clipped version of matrix representation. The influence of accidental blade equality on recognition is also studied. Finally, the efficiency of the GA model is compared to that of previously developed models.
The aim of our study was to explore whether or not different types of learners in a sensorimotor task possess characteristically different cognitive representations. Participants? sensorimotor adaptation performance was measured with a pointing paradigm which used a distortion of the visual feedback in terms of a left?right reversal. The structure of cognitive representations was assessed using a newly established experimental method, the Cognitive Measurement of Represented Directions. A post hoc analysis revealed inter-individual differences in participants? adaptation performance, and three different skill levels (skilled, average, and poor adapters) have been defined. These differences in performance were correlated with the structure of participants? cognitive representations of movem...
The configuration of mental representation of space plays a major role in successful navigational activities. Therefore, navigational assistance for pedestrians who are blind should help them to better configure their mental representation of the environment. In this paper, we propose and exploit a computational model for the mental representation of urban areas as an aid to orientation and navigation for visually impaired pedestrians. Our model uses image schemata to capture the spatial semantics and configural elements of urban space necessary for this purpose. These image schemata are schematic structures that are continually requested by individuals in their perception, bodily movement and interaction with surrounding objects. Our proposed model also incorporates a hierarchical structu...
Shaping of Object Representations in the Human Medial Temporal Lobe Based on Temporal Regularities
SummaryRegularities are gradually represented in cortex after extensive experience [1], and yet they can influence behavior after minimal exposure [2, 3]. What kind of representations support such rapid statistical learning? The medial temporal lobe (MTL) can represent information from even a single experience [4], making it a good candidate system for assisting in initial learning about regularities. We combined anatomical segmentation of the MTL, high-resolution fMRI, and multivariate pattern analysis to identify representations of objects in cortical and hippocampal areas of human MTL, assessing how these representations were shaped by exposure to regularities. Subjects viewed a continuous visual stream containing hidden temporal relationships-pairs of objects that reliably appeared nea...
It has been proposed that spatial relations are encoded either categorically, such that the relative positions of objects are defined in prepositional terms; or in terms of visual coordinates, such that the precise distances between objects are represented. In humans, it has been assumed that a left hemisphere neural network subserves categorical representations, and that coordinate representations are right lateralised. However, evidence in support of this distinction has been garnered exclusively from tasks that involved static, two-dimensional (2D) arrays. We used functional magnetic resonance imaging (fMRI) to identify neural circuits underlying categorical and coordinate representations during active spatial navigation. Activity in the categorical condition was significantly greater i...
Overview of EVE - the event visualization environment of ROOT
EVE is a high-level visualization library using ROOT's data-processing, GUI and OpenGL interfaces. It is designed as a framework for object management offering hierarchical data organization, object interaction and visualization via GUI and OpenGL representations. Automatic creation of 2D projected views is also supported. On the other hand, it can serve as an event visualization toolkit satisfying most HEP requirements: visualization of geometry, simulated and reconstructed data such as hits, clusters, tracks and calorimeter information. Special classes are available for visualization of raw-data. Object-interaction layer allows for easy selection and highlighting of objects and their derived representations (projections) across several views (3D, Rho-Z, R-Phi). Object-specific tooltips are provided in both GUI and GL views. The visual-configuration layer of EVE is built around a data-base of template objects that can be applied to specific instances of visualization objects to ensure consistent object presentation. The data-base can be retrieved from a file, edited during the framework operation and stored to file. EVE prototype was developed within the ALICE collaboration and has been included into ROOT in December 2007. Since then all EVE components have reached maturity. EVE is used as the base of AliEve visualization framework in ALICE, Firework physics-oriented event-display in CMS, and as the visualization engine of FairRoot in FAIR.
The Impact of Visual Appearance on User Response in Online Display Advertising
Display advertising has been a significant source of revenue for publishers and ad networks in online advertising ecosystem. One of the main goals in display advertising is to maximize user response rate for advertising campaigns, such as click through rates (CTR) or conversion rates. Although in the online advertising industry we believe that the visual appearance of ads (creatives) matters for propensity of user response, there is no published work so far to address this topic via a systematic data-driven approach. In this paper we quantitatively study the relationship between the visual appearance and performance of creatives using large scale data in the world's largest display ads exchange system, RightMedia. We designed a set of 43 visual features, some of which are novel and some are inspired by related work. We extracted these features from real creatives served on RightMedia. We also designed and conducted a series of experiments to evaluate the effectiveness of visual features for CTR prediction, ra...
In order to enable students who are blind and visually impaired to observe chemical changes in solutions, a hand-held device was designed to output light intensity as an audible tone. The submersible audible light sensor (SALS) creates an audio signal by which one can observe reactions in a solution in real time, using standard laboratory glassware such as test tubes or beakers. Because many observations in the chemistry laboratory are visual, the SALS device enables students who are blind and visually impaired to perform a broader range of experiments independently. It is believed that this active participation will inspire more of these students to pursue careers in the science, technology, engineering, and mathematics (STEM) professions. The SALS device can be further refined to provide vibratory and visual outputs for students with learning or physical disabilities. (Contains 3 figures.)
GammaModeler TM 3-D gamma-ray imaging technology
The 3-D GammaModeler{trademark} system was used to survey a portion of the facility and provide 3-D visual and radiation representation of contaminated equipment located within the facility. The 3-D GammaModeler{trademark} system software was used to deconvolve extended sources into a series of point sources, locate the positions of these sources in space and calculate the 30 cm. dose rates for each of these sources. Localization of the sources in three dimensions provides information on source locations interior to the visual objects and provides a better estimate of the source intensities. The three dimensional representation of the objects can be made transparent in order to visualize sources located within the objects. Positional knowledge of all the sources can be used to calculate a map of the radiation in the canyon. The use of 3-D visual and gamma ray information supports improved planning decision-making, and aids in communications with regulators and stakeholders.
The GEANT4 Visualisation System
The Geant4 Visualization System is a multi-driver graphics system designed to serve the Geant4 Simulation Toolkit. It is aimed at the visualization of Geant4 data, primarily detector descriptions and simulated particle trajectories and hits. It can handle a variety of graphical technologies simultaneously and interchangeably, allowing the user to choose the visual representation most appropriate to requirements. It conforms to the low-level Geant4 abstract graphical user interfaces and introduces new abstract classes from which the various drivers are derived and that can be straightforwardly extended, for example, by the addition of a new driver. It makes use of an extendable class library of models and filters for data representation and selection. The Geant4 Visualization System supports a rich set of interactive commands based on the Geant4 command system. It is included in the Geant4 code distribution and maintained and documented like other components of Geant4.
Avatars in flux : blurring the boundaries of a unified phenomenon of bounded contours
There is an almost unquestioned consensus in the virtual worlds’ research communities that an avatar is the representation of a user and player in front of the screen and that the relationship between the two predominantly is about identity and self-construal. Richard Bartle’s (2004) influential work and his claim that “it is all about identity” has been widely adopted. In many studies this conception has been explored and substantial contributions have been made (Downs 2010, Filiciak 2003, Fox & Bailenson 2009, Jin & Park 2009, Wang & Chang 2004, and Yee 2006). In this paper, I will, however, question the consensus to suggest that we nuance and broaden our understanding of the relationships of avatars with their owners. The question that I will set out to answer is: In what ways do actors make sense of their choice and design of avatars? The empirical basis for addressing this question is found in iterative video interviews with actors while they act in their chosen virtual worlds and with their avatars. The video interviews have been conducted in situ together with actors on the locations of their usual play and practice – be it at home or at their work place. The methodological approach of the in situ video interviews is summarized by the notion of “following the actors,” even if it is also recognized that the optic of the researcher is different from that of the engaged actor, who is seen as the expert of his or her engagement and agency. Over time, when located beside the actors while they act and engage, gradually, the conception of an avatar as the representation of the actor has become questionable. During the interviews, discussing with the actors their relationship with the chosen avatars, increasingly the transformative aspects of the relationship has influenced the theoretical understanding explicated by this paper, and it has blurred the boundaries of a seemingly unified phenomenon with bounded contours. Hence, a phenomenon in flux has emerged and become ever more visible during the in situ studies. The paper therefore suggests that we nuance our analysis and explicate the multiple and emergent constructions as well as the stabilizing interpretations of the relationships between actor and avatar. Semiotics (Nöth 2009, Peirce 1994) and actor-network theory (Latour 1998, 2005, Law 2004, Star 1995) are some of the theoretical references that will assist and enable such analysis. Moreover, this paper will discuss how the methodological approach inspired by visual ethnography (Grimshaw 2001, Pink 2001, 2006) and the theoretical analysis of the phenomenon of avatars have mutually constructed and conceptualized the multiplicity of a transformative phenomenon. Following the methodological reflections and the theoretical and empirical analysis, the paper concludes that the relationships of actors and avatars 1) continuously oscillate and change as they 2) translate and transform the actors and their agency when enacted and performed. It is suggested that the understanding of avatars as interpretants and mediators in companionate relations will help us interpret and understand avatars as transformative phenomena in flux with blurred boundaries and not only as a bounded representation of actors in relations of projection, identification, self-construal, and identity-making.
Avatars in Flux : blurring the boundaries of a unified phenomenon of bounded contours
There is an almost unquestioned consensus in the virtual worlds‘ research communities that an avatar is the representation of a user and player in front of the screen and that the relationship between the two predominantly is about identity and self-construal. Richard Bartle‘s (2004) influential work and his claim that ?it is all about identity? has been widely adopted. In many studies this conception has been explored and substantial contributions have been made (Downs 2010, Filiciak 2003, Fox & Bailenson 2009, Jin & Park 2009, Wang & Chang 2004, and Yee 2006). In this paper, I will, however, question the consensus to suggest that we nuance and broaden our understanding of the relationships of avatars with their owners. The question that I will set out to answer is: In what ways do actors make sense of their choice and design of avatars? The empirical basis for addressing this question is found in iterative video interviews with actors while they act in their chosen virtual worlds and with their avatars. The video interviews have been conducted in situ together with actors on the locations of their usual play and practice – be it at home or at their work place. The methodological approach of the in situ video interviews is summarized by the notion of ?following the actors,? even if it is also recognized that the optic of the researcher is different from that of the engaged actor, who is seen as the expert of his or her engagement and agency. Over time, when located beside the actors while they act and engage, gradually, the conception of an avatar as the representation of the actor has become questionable. During the interviews, discussing with the actors their relationship with the chosen avatars, increasingly the transformative aspects of the relationship has influenced the theoretical understanding explicated by this paper, and it has blurred the boundaries of a seemingly unified phenomenon with bounded contours. Hence, a phenomenon in flux has emerged and become ever more visible during the in situ studies. The paper therefore suggests that we nuance our analysis and explicate the multiple and emergent constructions as well as the stabilizing interpretations of the relationships between actor and avatar. Semiotics (Nöth 2009, Peirce 1994) and actor-network theory (Latour 1998, 2005, Law 2004, Star 1995) are some of the theoretical references that will assist and enable such analysis. Moreover, this paper will discuss how the methodological approach inspired by visual ethnography 2 (Grimshaw 2001, Pink 2001, 2006) and the theoretical analysis of the phenomenon of avatars have mutually constructed and conceptualized the multiplicity of a transformative phenomenon. Following the methodological reflections and the theoretical and empirical analysis, the paper concludes that the relationships of actors and avatars 1) continuously oscillate and change as they 2) translate and transform the actors and their agency when enacted and performed. It is suggested that the understanding of avatars as interpretants and mediators in companionate relations will help us interpret and understand avatars as transformative phenomena in flux with blurred boundaries and not only as a bounded representation of actors in relations of projection, identification, self-construal, and identity-making. Keywords: avatars, companionate relations, mediators, flux, video interviews, actor-network theory, semiotics.
This document contains 59 selected papers from the 1996 International Visual Literacy Association (IVLA) conference. Topics include: learning to think visually; information design via the Internet; a program for inner-city at-risk children; dubbing versus subtitling television programs; connecting advertisements and classroom reading through visual literacy; tools for humanizing visual symbols; a review of a video on advertising and obsession with thinness; hypermedia and the fundamentals of electronic literacy; elementary students' perceptions of visuals on the World Wide Web; stereotypes in film; teachers' perceptions of instructional design; visual learning activities; tri-coding of information; diversity in Cyborg images; concept mapping; the meaning of color in trademarks; visual literacy in elementary education; visual learning via computer-based simulations; adapting a paper-and-pencil test to the computer; representational strategies in a documentary about racial relations; studying scientific data through an aesthetic point of view; the role of the media in African American self-hatred; the need for visual literacy in higher education; imagery and synectics for modeling poetry writing; virtual courses; visual icons in myth; the development and demise of 8 millimeter film loops; women's history in visual and audiovisual education; student-developed visual productions; a cartographic interpretation of visual literacy; enabling learners through technology; a graphics systems approach in industry; the philosophy of representation; student nurses' perceptions of hospital staff modelling behaviors; deconstructing visual images of indigenous people; children's spatial visual thinking in a hypermedia environment; creating critical thinkers; perception in physics; using graphics for integrated planning; revisioning in storytelling; a local history preservation project; visual learning in biology; imagery, concept formation and creativity; visual themes in gravestones; visual design principles in World Wide Web construction; digital camera editing; digital cinema principles and techniques for multimedia development; culture reflected in tombstones; challenges for hypermedia designers; visual literacy in Web Page creation; the potential of dynamic computer presentations; technology mass media, society and gender; obstructive interactive television designs; gender equity online; a study of intertextuality in television programming; children's understanding of visuals in television interviews; children's attention in television viewing; instructional design process models; and international use of the electronic presentation. (AEF)
We visualized the intraparotid facial nerve and parotid duct at 3 tesla using 3-dimensional reversed fast imaging with steady-state precession (FSIP) (3D-PSIF) with diffusion weighting. Excellent fat suppression by water-selective excitation, sufficient T2-weighting of 3D-PSIF, vessel suppression by diffusion weighting, and high spatial resolution allowed the simultaneous visualization. We also present volumetric representation of the facial nerve and duct.
The paper gives an overview on the role of the image in the human knowledge process. The mental representation in the visual communication is presented in detailed The Icon is studied and classified for the informatic applications. Emphasis is placed on ENEA activities to realized access interface to Data Bases. These are aimed at the Information Dissemination and Technological Transfer. The research level and the future perspective of the visual interface in the communication field are analyzed.
The Digital Space Shuttle, 3D Graphics, and Knowledge Management
The Digital Shuttle is a knowledge management project that seeks to define symbiotic relationships between 3D graphics and formal knowledge representations (ontologies). 3D graphics provides geometric and visual content, in 2D and 3D CAD forms, and the capability to display systems knowledge. Because the data is so heterogeneous, and the interrelated data structures are complex, 3D graphics combined with ontologies provides mechanisms for navigating the data and visualizing relationships.
Currently, we lack consensus regarding the organization along the anterior border of dorsomedial V2 in primates. Previous studies suggest that this region could be either the dorsomedial area, characterized by both an upper and a lower visual field representation, or the dorsal aspect of area V3, which only contains a lower visual field representation. We examined these proposals by using optical imaging of intrinsic signals to investigate this region in the prosimian galago (Otolemur garnettii). Galagos represent the prosimian radiation of surviving primates; cortical areas that bear strong resemblances across members of primates provide a strong argument for their early origin and conserved existence. Based on our mapping of horizontal and vertical meridian representations, visuotopy, and orientation preference, we find a clear lower field representation anterior to dorsal V2 but no evidence of any upper field representation. We also show statistical differences in orientation preference patches between V2 and V3. We additionally supplement our imaging results with electrode array data that reveal differences in the average spatial frequency preference, average temporal frequency preference, and sizes of the receptive fields between V1, V2, and V3. The lack of upper visual field representation along with the differences between the neighboring visual areas clearly distinguish the region anterior to dorsal V2 from earlier visual areas and argue against a DM that lies along the dorsomedial border of V2. We submit that the region of the cortex in question is the dorsal aspect of V3, thus strengthening the possibility that V3 is conserved among primates. J. Comp. Neurol., 2012. © 2012 Wiley Periodicals, Inc. PMID:22628051
Perceptual control architecture for cyber-physical systems in traffic incident management
Based on Perceptual Control Theory, we study the problem of unified modeling for incompatible approaches of Cyber-Physical Systems (CPSs). Inspired by the effective organization of living systems structure accommodating heterogeneous information processing and environmental interaction, we propose Perceptual Control Architecture of CPSs, and take Traffic Incident Management systems as the modeling research carrier. Throughout the structure of Traffic Incident Management systems, the hierarchical negative feedback is constituted by perceptual and behavioral loops to ensure a mechanism of intelligence behavior. The internal representation is categorized into two intelligent spaces: physical-reflex space and cyber-virtual space. In physical-reflex space, the sensing-actuation mapping of objec...
Searching for the conformal window
Undeniably, the imminent activity of LHC and the quest for the nature of physics beyond the standard model have raised renewed interest in the conformal and quasi-conformal behaviour of gauge field theories with matter content. Theoretically driven questions seem to now acquire a strong experimental appeal and might guide us towards a more realistic string theory to field theory connection, originally inspired by the AdS/CFT conjecture. In this brief report, we discuss the state of the art of our search for the conformal window in the SU(3) colour-gauge theory with fermions in the fundamental representation.
The Endomembrane System: A Representation of the Extracellular Medium?
Both prokaryotic and eukaryotic cells share the basic mechanisms of secretory protein synthesis. However, unlike prokaryotes, eukaryotic cells posses a system of compartments, the so-called endomembrane system, which are involved in the synthesis process. A comparison of the prokaryotic and eukaryotic protein synthesis processes and particularly the observation of the functional and structural similarity between the prokaryotic cell membrane (the interface to the cell exterior) and the membrane of the eukaryotic endoplasmic reticulum (one of the compartments within the endomembrane system) inspire a description that refers to either the eukaryotic endoplasmic reticulum or its membrane or the endomembrane system altogether as a representation of the extracellular medium. However, unless the...
Objective measurement of dysarthric speech intelligibility can assist clinicians in the diagnosis of speech disorder severity as well as in the evaluation of dysarthria treatments. In this paper, several objective measures are proposed and tested as correlates of subjective intelligibility. More specifically, the kurtosis of the linear prediction residual is proposed as a measure of vocal source excitation oddity. Additionally, temporal perturbations resultant from imprecise articulation and atypical speech rates are characterized by short- and long-term temporal dynamics measures, which in turn, are based on log-energy dynamics and on an auditory-inspired modulation spectral signal representation, respectively. Motivated by recent insights in the communication disorders literature, a comp...
Abstract Current theories suggest that disrupting cortical information integration may account for the mechanism of general anesthesia in suppressing consciousness. Human cognitive operations take place in hierarchically structured neural organizations in the brain. The process of low-order neural representation of sensory stimuli becoming integrated in high-order cortices is also known as cognitive binding. Combining neuroimaging, cognitive neuroscience, and anesthetic manipulation, we examined how cognitive networks involved in auditory verbal memory are maintained in wakefulness, disrupted in propofol-induced deep sedation, and re-established in recovery. Inspired by the notion of cognitive binding, an functional magnetic resonance imaging-guided connectivity analysis was utilized to as...
Non-Hermitian model for resonant cavities coupled by a chiral mirror
Inspired by a recently observed asymmetry in the transmission of circularly polarized light through a metamaterial, we present a non-Hermitian PT -symmetric quantum model to describe the interaction of the light fields in two resonant cavities coupled via a 2D-chiral mirror. We compute the time evolution of the light fields in this model, find two sets of operators compatible with the Hamiltonian in a delocalized representation, discover the energies of the system and show that the transmission probability predicted by the model is indeed asymmetric.
Accessing complexity from genome information
This paper studies the information content of the chromosomes of 24 species. In a first phase, a scheme inspired in dynamical system state space representation is developed. For each chromosome the state space dynamical evolution is shed into a two dimensional chart. The plots are then analyzed and characterized in the perspective of fractal dimension. This information is integrated in two measures of the species' complexity addressing its average and variability. The results are in close accordance with phylogenetics pointing quantitative aspects of the species' genomic complexity.
Density-matrix-based algorithm for solving eigenvalue problems
A fast and stable numerical algorithm for solving the symmetric eigenvalue problem is presented. The technique deviates fundamentally from the traditional Krylov subspace iteration based techniques (Arnoldi and Lanczos algorithms) or other Davidson-Jacobi techniques and takes its inspiration from the contour integration and density-matrix representation in quantum mechanics. It will be shown that this algorithm—named FEAST—exhibits high efficiency, robustness, accuracy, and scalability on parallel architectures. Examples from electronic structure calculations of carbon nanotubes are presented, and numerical performances and capabilities are discussed.
CHAMPION: Intelligent Hierarchical Reasoning Agents for Enhanced Decision Support
We describe the design and development of an advanced reasoning framework employing semantic technologies, organized within a hierarchy of computational reasoning agents that interpret domain specific information. Designed based on an inspirational metaphor of the pattern recognition functions performed by the human neocortex, the CHAMPION reasoning framework represents a new computational modeling approach that derives invariant knowledge representations through memory-prediction belief propagation processes that are driven by formal ontological language specification and semantic technologies. The CHAMPION framework shows promise for enhancing complex decision making in diverse problem domains including cyber security, nonproliferation and energy consumption analysis.
Proteus: a web-based, context-specific modelling tool for molecular networks
Summary: Molecular networks are often studied in diverse cellular or experimental contexts, with highly context-specific details. Modelling introduces further choices as to levels of mathematical description. The resulting possibilities are difficult to explore rapidly, hampering the integration of modelling and experiment. We have developed Proteus, a web-based, context-specific tool for building compartmentalized, ordinary differential equation (ODE) models. It is inspired by the idea of a molecular `toolkit' for Ca2+ signalling. Toolkits in Proteus are context-independent representations of biological systems as sets of components, which may correspond to mechanisms of differing levels of complexity. Users pick and choose components from a toolkit and, for each component, pick and choos...
Learning Analytics: A Case Study of the Process of Design of Visualizations
The ability to visualize student engagement and experience data provides valuable opportunities for learning support and curriculum design. With the rise of the use of learning analytics to provide "actionable intelligence" on students' learning, the challenge is to create visualizations of the data, which are clear and useful to the intended audience. This process of finding the best way to visually represent data is often iterative, with many different designs being trialled before the final design is settled upon. This paper presents a case study of the process of refining a visualization of students' learning experience data. In this case the aim was to create a visual representation of the continuity of care students were exposed to during a longitudinal placement as part of a medical degree. The process of visualization refinement is outlined as well as the lessons learned along the way. (Contains 5 figures.)
Abstract in portuguese Apesar de intensamente pesquisados nos últimos trinta anos, os processos cognitivos relacionados à atenção visual humana ainda apresentam várias lacunas e instigam investigações sobre os mecanismos de seleção e integração da informação relevante contida no ambiente. Basicamente, os esforços para a compreensão desta arquitetura cognitiva estão centrados em dois grandes modelos teóricos sobre a atenção visual: um baseado na localização espacial ocupada (more) pelos objetos no campo visual e outro baseado nas características do objeto a ser atendido. A revisão realizada neste artigo busca sistematizar algumas contribuições experimentais importantes a respeito desses modelos bem como evidenciar algumas particularidades da natureza dos processos envolvidos na mobilização da atenção visual humana. Abstract in english The study of visual attention has become an important topic in cognitive psychology research in the last 30 years. However, many questions about the nature of attention are not well understood. The efforts to understand this cognitive architecture are centered in two great theoretical models on the visual attention: the first model supports that visual attention is allocated on visual space (location-based visual attention) while a second model supports that attention cou (more) ld select the objects representations per se (object-based visual attention). In this review, we pooled important researches about these two seminal models and some questions concerning the human visual attention were examined.
A new image representation for compact and secure communication
In many areas of nuclear materials management there is a need for communication, archival, and retrieval of annotated image data between heterogeneous platforms and devices to effectively implement safety, security, and safeguards of nuclear materials. Current image formats such as JPEG are not ideally suited in such scenarios as they are not scalable to different viewing formats, and do not provide a high-level representation of images that facilitate automatic object/change detection or annotation. The new Scalable Vector Graphics (SVG) open standard for representing graphical information, recommended by the World Wide Web Consortium (W3C) is designed to address issues of image scalability, portability, and annotation. However, until now there has been no viable technology to efficiently field images of high visual quality under this standard. Recently, LANL has developed a vectorized image representation that is compatible with the SVG standard and preserves visual quality. This is based on a new geometric framework for characterizing complex features in real-world imagery that incorporates perceptual principles of processing visual information known from cognitive psychology and vision science, to obtain a polygonal image representation of high fidelity. This representation can take advantage of all textual compression and encryption routines unavailable to other image formats. Moreover, this vectorized image representation can be exploited to facilitate automated object recognition that can reduce time required for data review. The objects/features of interest in these vectorized images can be annotated via animated graphics to facilitate quick and easy display and comprehension of processed image content.
This study investigated the modes of representations generated by kindergarteners and first graders while solving standard and problematic problems in mathematics. Furthermore, it examined the influence of pupils' visual representations on the breach of the didactical contract rules in problem solving. The sample of the study consisted of 38 kindergarteners (age 5-6) and 34 first graders (age 6-7). Two standard problems (addition and subtraction) and two problematic problems were given to the participants. The majority of kindergarteners used a variety of spontaneous visual representations in order to solve both types of problems. In contrast, first graders mainly used symbolic representations corresponding to the numbers involved in the text of the problems. Results also suggested that the visual representations prevented kindergarteners from obeying the didactical contract rules. In fact, many kindergarteners were inclined to draw descriptive pictures about the meaning of the problems, without persevering in giving a symbolic answer in the standard problems or providing a stereotyped solution for the problematic problems. First graders, however, gave a routine solution, that is, a symbolic answer to the two problematic problems, complying with the didactical contract rule that every problem given to them has an answer. (Contains 4 tables and 11 figures.)
A visual system module giving internal image representations processes the two images. ... However, when the template models assume a single, unchanging memory ... uncertainty: (i) Gabor versus checkerboard targets and (ii) eccentricity. 13 .... Auditory feedback was given if the keyboard response was incorrect.
The present study aims to investigate the effects of a design experiment developed for third-grade students in the field of mathematics word problems. The main focus of the program was developing students' knowledge about word problem solving strategies with an emphasis on the role of visual representations in mathematical modeling. The experiment involved five experimental and six control classes ("N" = 106 and 138, respectively) of third-grade students. The experiment comprised 20 lessons with 73 word problems, providing a systematic overview of the basic word problem types. Teachers of the experimental classes received a booklet containing lesson plans and overhead transparencies with different types of visual representations attached to the word problems. Students themselves were invited to make drawings for each task, and group work and teacher-led discussion shaped their beliefs about the role of visual representations in word problem solving. The effect sizes of the experiment were calculated from the results of two tests: an arithmetic skill and a word problem test, and the unbiased estimates for Cohen's "d" proved to be 0.20 and 0.62. There were significant changes also in experimental group students' beliefs about mathematics. The experiment pointed to the possibility, feasibility, and importance of learning about visual representations in mathematical word problem solving as early as in grade 3 (around age 9-10).
The neural representation of motion aftereffects induced by various visual flows (translational, rotational, motion-in-depth, and translational transparent flows) was studied under the hypothesis that the imbalances in discharge activities would occur in favor in the direction opposite to the adapti...
Gender in Facial Representations: A Contrast-Based Study of Adaptation within and between the Sexes
Face aftereffects are proving to be an effective means of examining the properties of face-specific processes in the human visual system. We examined the role of gender in the neural representation of faces using a contrast-based adaptation method. If faces of different genders share the same repres...
Are Sparse Representations Really Relevant for Image Classification?
Recent years have seen an increasing interest in sparse representations for image classi?cation and object recognition, probably motivated by evidence from the analysis of the primate visual cortex. It is still unclear, however, whether or not sparsity helps classi?cation. In this paper we evaluate ...
A native XML database supporting approximate match search
XML is becoming the standard representation format for metadata. Metadata for multimedia documents, as for instance MPEG-7, require approximate match search functionalities to be supported in addition to exact match search. As an example, consider image search performed by using MPEG-7 visual descri...
Writing and Speech Recognition : Observing Error Correction Strategies of Professional Writers
In this thesis we describe the organization of speech recognition based writing processes. Writing can be seen as a visual representation of spoken language: a combination that speech recognition takes full advantage of. In the field of writing research, speech recognition is a new writing instrumen...
Laboratory experiments and computer models for studying the mass transfer process of removing CO2 from air using water or dilute NaOH solution as absorbent are presented. Models tie experiment to theory and give a visual representation of concentration profiles and also illustrate the two-film theory and the relative importance of various resistances to mass transfer with and without reaction.
Development of A Taxonomy of Representational Affordances for Electronic Health Record System
The application of Gibson’s concept of affordances in Human-Computer Interaction (HCI) has lead to user interface improvements in many fields, like planning and visual environment. Design of user interface (representation) is very important to the functionality and usability of Electronic Health Rec...
Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.
This article is about the camera operators who worked alongside the key film-directors of the Soviet avant-garde. This was a period when, on a theoretical level, cinema was increasingly defined in terms of photography and as a visual means of representation. Within the collaborative nature of the av...
Visualization strategies for major white matter tracts for intraoperative use
Streamline representation of major fiber tract systems along with high-resolution anatomical data provides a reliable orientation for the neurosurgeon. For intraoperative visualization of these data either on navigation screens near the surgical field or directly in the surgical field applying heads...
Streamline representation of major fiber tract systems along with high-resolution anatomical data provides a reliable orientation for the neurosurgeon. For direct visualization of these data in the surgical field applying heads-up displays of operating microscopes, wrapping of all streamlines of int...
Blind Audiovisual Source Separation Using Sparse Representations
In this work we present a method to jointly separate active audio and visual structures on a given mixture. Blind Audiovisual Source Separation is achieved exploiting the coherence between a video signal and a one-microphone audio track. The efficient representation of audio and video sequences a...
Speech Recognition by Human and Machine
Several feature extraction techniques, algorithms and toolkits are researched to investigate how speech recognition is performed. Spectrograms were found to be the simplest feature extraction techniques for visual representation of speech, and are explored and experimented with to see how phonemes...
Invariance of brain-wave representations of simple visual images and their names
In two experiments, electric brain waves of 14 subjects were recorded under several different conditions to study the invariance of brain-wave representations of simple patches of colors and simple visual shapes and their names, the words blue, circle, etc. As in our earlier work, the analysis consi...
Scale robust adaptive feature density approximation for visual object representation and tracking
Feature density approximation (FDA) based visual object appearance representation is emerging as an effective method for object tracking, but its challenges come from object's complex motion (e.g. scaling, rotation) and the consequent object's appearance variation. The traditional adaptive FDA metho...
Between Gazes: Feminist, Queer, and 'Other' Films
In this book Camelia Elias introduces key terms in feminist, queer, and postcolonial/diaspora film. Taking her point of departure in the question, "what do you want from me?" she detours through Lacanian theory of the gaze and reframes questions of subjectivity and representation in an entertaining entanglement of visual with textual poetics in film.
Large-Area Photo-Mosaics Using Global Alignment and Navigation Data
Seafloor imagery is a rich source of data for the study of biological and geological processes. Among several applications, still images of the ocean floor can be used to build image composites referred to as photo-mosaics. Photo-mosaics provide a wide-area visual representation of the benthos, and ...
Viewgraphs on DataHub knowledge based assistance for science visualization and analysis using large distributed databases. Topics covered include: DataHub functional architecture; data representation; logical access methods; preliminary software architecture; LinkWinds; data knowledge issues; expert systems; and data management.
Maps have been important elements of visual representation in the development of different societies, and for this reason they have mainly been considered from a practical and utilitarian point of view. This means that cartographers or mapmakers have largely focused on the technical aspects of the c...
Graphic Representation and Visualisation as Modelling Support for the Knowledge Acquisition Process
The thesis describes steps taken towards using graphic representation and visual modelling support for the knowledge acquisition process in knowledge-based systems – a process commonly regarded as difficult. The performance of the systems depends on the quality of the embedded knowledge, which ma...
Approximation of Besov vectors by Paley-Wiener vectors in Hilbert spaces
We develop an approximation theory in Hilbert spaces that generalizes the classical theory of approximation by entire functions of exponential type. The results advance harmonic analysis on manifolds and graphs, thus facilitating data representation, compression, denoising and visualization. These tasks are of great importance to machine learning, complex data analysis and computer vision.
Visual tracking with omnidirectional cameras: an efficient approach
An effective technique for applying visual tracking algorithms to omni- directional image sequences is presented. The method is based on a spherical image representation which allows taking into account the distortions and nonlinear resolution of omnidirectional images. Experimental results show tha...
Local Space-Time Smoothing for Versioned Documents
Unlike static documents, versioned documents are continuously edited by one or more authors. Such collaborative revision process makes traditional modeling and visualization techniques inappropriate. In this paper we propose a new representation based on local space-time smoothing that captures important revision patterns. We demonstrate the applicability of our framework using experiments on synthetic and real-world data.
Ontology Based Complex Object Recognition
This paper presents a new approach for object categorization involving the following aspects of cognitive vision: learning, recognition and knowledge representation.A major element of our approach is a visual concept ontology composed of several types of concepts (spatial concepts and relations, col...
AUTONOMOUS NAVIGATION NEAR ASTEROID BASED ON VISUAL SLAM ... The very rugged surface of SCB's makes safe landing sites sparse and narrow, requiring precision ..... signatures and an octree occupancy tree (left) representation in memory (right) ..... Int. Conf. on Computer Vision and Pattern Recognition, San ...
Digital Egypt: reconstructions from Egypt on the World Wide Web
This chapter focuses on a joint project, Digital Egypt for Universities, between CASA and the Petrie Museum of Egyptian Archaeology. Taking copyrighted images, we assemble an online resource on Egyptian archaeology, which offers a wide range of audio-visual representations of this ancient culture an...
Reweighted atomic densities to represent ensembles of NMR structures
A reweighted atomic probability density is introduced as a means of representing ensembles of NMR structures in a simple, concise and informative manner. This density is shown to give a better visual representation of molecular structure information than an unweighted density, and should provide a useful interactive graphics tool during the course of iterative NMR structure refinement. The approach is illustrated using several examples.
Multiresolution modeling and visualization of volume data based on simplicial complexes
A scattered volumetric dataset is regarded as a sampled version of a scalar field defined ona three dimensional domain, whose graph is a hypersurface embedded in a four dimensional space. We propose a multiresolution model for the representation and visualization of such data that is based on a deco...
The movement of motion-defined contours can bias perceived position
Illusory position shifts induced by motion suggest that motion processing can interfere with perceived position. This may be because accurate position representation is lost during successive visual processing steps. We found that complex motion patterns, which can only be extracted at a global leve...
A Multi-Resolution Data Structure for Two-Dimensional Morse Functions
The efficient construction of simplified models is a central problem in the field of visualization. We combine topological and geometric methods to construct a multi-resolution data structure for functions over two-dimensional domains. Starting with the Morse-Smale complex we build a hierarchy by progressively canceling critical points in pairs. The data structure supports mesh traversal operations similar to traditional multi-resolution representations.
Quantum-Like Uncertain Conditionals for Text Analysis
Simple representations of documents based on the occurrences of terms are ubiquitous in areas like Information Retrieval, and also frequent in Natural Language Processing. In this work we propose a logical-probabilistic approach to the analysis of natural language text based in the concept of Uncertain Conditional, on top of a formulation of lexical measurements inspired in the theoretical concept of ideal quantum measurements. The proposed concept can be used for generating topic-specific representations of text, aiming to match in a simple way the perception of a user with a pre-established idea of what the usage of terms in the text should be. A simple example is developed with two versions of a text in two languages, showing how regularities in the use of terms are detected and easily represented.
From Royal Road to Epistatic Road for Variable Length Evolution Algorithm
Although there are some real world applications where the use of variable length representation (VLR) in Evolutionary Algorithm is natural and suitable, an academic framework is lacking for such representations. In this work we propose a family of tunable fitness landscapes based on VLR of genotypes. The fitness landscapes we propose possess a tunable degree of both neutrality and epistasis; they are inspired, on the one hand by the Royal Road fitness landscapes, and the other hand by the NK fitness landscapes. So these landscapes offer a scale of continuity from Royal Road functions, with neutrality and no epistasis, to landscapes with a large amount of epistasis and no redundancy. To gain insight into these fitness landscapes, we first use standard tools such as adaptive walks and correlation length. Second, we evaluate the performances of evolutionary algorithms on these landscapes for various values of the neutral and the epistatic parameters; the results allow us to correlate the performances with the ex...
Hamiltonian and physical Hilbert space in polymer quantum mechanics
In this paper, a version of polymer quantum mechanics, which is inspired by loop quantum gravity, is considered and shown to be equivalent, in a precise sense, to the standard, experimentally tested, Schroedinger quantum mechanics. The kinematical cornerstone of our framework is the so called polymer representation of the Heisenberg-Weyl (H-W) algebra, which is the starting point of the construction. The dynamics is constructed as a continuum limit of effective theories characterized by a scale, and requires a renormalization of the inner product. The result is a physical Hilbert space in which the continuum Hamiltonian can be represented and that is unitarily equivalent to the Schroedinger representation of quantum mechanics. As a concrete implementation of our formalism, the simple harmonic oscillator is fully developed.
Simulating Spiking Neural P systems without delays using GPUs
We present in this paper our work regarding simulating a type of P system known as a spiking neural P system (SNP system) using graphics processing units (GPUs). GPUs, because of their architectural optimization for parallel computations, are well-suited for highly parallelizable problems. Due to the advent of general purpose GPU computing in recent years, GPUs are not limited to graphics and video processing alone, but include computationally intensive scientific and mathematical applications as well. Moreover P systems, including SNP systems, are inherently and maximally parallel computing models whose inspirations are taken from the functioning and dynamics of a living cell. In particular, SNP systems try to give a modest but formal representation of a special type of cell known as the neuron and their interactions with one another. The nature of SNP systems allowed their representation as matrices, which is a crucial step in simulating them on highly parallel devices such as GPUs. The highly parallel natu...
Exploring brain connectivity with two-dimensional neural maps.
We introduce two-dimensional neural maps for exploring connectivity in the brain. For this, we create standard streamtube models from diffusion-weighted brain imaging data sets along with neural paths hierarchically projected into the plane. These planar neural maps combine desirable properties of low-dimensional representations, such as visual clarity and ease of tract-of-interest selection, with the anatomical familiarity of 3D brain models and planar sectional views. We distribute this type of visualization both in a traditional stand-alone interactive application and as a novel, lightweight web-accessible system. The web interface integrates precomputed neural-path representations into a geographical digital-maps framework with associated labels, metrics, statistics, and linkouts. Anecdotal and quantitative comparisons of the present method with a recently proposed 2D point representation suggest that our representation is more intuitive and easier to use and learn. Similarly, users are faster and more accurate in selecting bundles using the 2D path representation than the 2D point representation. Finally, expert feedback on the web interface suggests that it can be useful for collaboration as well as quick exploration of data. PMID:21519105
Visual Representations of DNA Replication: Middle Grades Students' Perceptions and Interpretations
Visual representations play a critical role in the communication of science concepts for scientists and students alike. However, recent research suggests that novice students experience difficulty extracting relevant information from representations. This study examined students' interpretations of visual representations of DNA replication. Each of the four steps of DNA replication included in the instructional presentation was represented as a text slide, a simple 2D graphic, and a rich 3D graphic. Participants were middle grade girls (n = 21) attending a summer math and science program. Students' eye movements were measured as they viewed the representations. Participants were interviewed following instruction to assess their perceived salient features. Eye tracking fixation counts indicated that the same features (look zones) in the corresponding 2D and 3D graphics had different salience. The interviews revealed that students used different characteristics such as color, shape, and complexity to make sense of the graphics. The results of this study have implications for the design of instructional representations. Since many students have difficulty distinguishing between relevant and irrelevant information, cueing and directing student attention through the instructional representation could allow cognitive resources to be directed to the most relevant material.
We propose a two-stage learning method which implements occluded visual scene analysis into a generative model, a type of hierarchical neural network with bi-directional synaptic connections. Here, top-down connections simulate forward optics to generate predictions for sensory driven low-level representation, whereas bottom-up connections function to send the prediction error, the difference between the sensory based and the predicted low-level representation, to higher areas. The prediction error is then used to update the high-level representation to obtain better agreement with the visual scene. Although the actual forward optics is highly nonlinear and the accuracy of simulated forward optics is crucial for these types of models, the majority of previous studies have only investigated...
Decision support systems and methods for complex networks
Methods and systems for automated decision support in analyzing operation data from a complex network. Embodiments of the present invention utilize these algorithms and techniques not only to characterize the past and present condition of a complex network, but also to predict future conditions to help operators anticipate deteriorating and/or problem situations. In particular, embodiments of the present invention characterize network conditions from operation data using a state estimator. Contingency scenarios can then be generated based on those network conditions. For at least a portion of all of the contingency scenarios, risk indices are determined that describe the potential impact of each of those scenarios. Contingency scenarios with risk indices are presented visually as graphical representations in the context of a visual representation of the complex network. Analysis of the historical risk indices based on the graphical representations can then provide trends that allow for prediction of future network conditions.
This article presents a theoretical model of the process by which students construct and elaborate explanations of scientific phenomena using visual representations. The model describes progress in the underlying conceptual processes in students' explanations as a reorganization of fine-grained knowledge elements based on the Knowledge in Pieces perspective. The core case study involved a pair of fifth-grade students who generated visual representations to explain the phases of the moon and collaboratively elaborated and improved their representations and explanations. The model describes the process of developing explanations as iterations of temporarily stable stages of coherence. The progression from one temporary coherent structure to the next is described as the increase of "Resolution" and/or "Range" of the explanation. "Resolution" and "Range" are newly defined theoretical constructs. The model accounts for the continuity in the students' developing understanding and highlights the productive nature of their intuitive knowledge resources. (Contains 7 footnotes and 18 figures.)
Intrinsic signal optical imaging evidence for dorsal V3 in the prosimian galago (Otolemur garnettii)
Abstract Currently, we lack consensus regarding the organization along the anterior border of dorsomedial V2 in primates. Previous studies suggest that this region could be either the dorsomedial area, characterized by both an upper and a lower visual field representation, or the dorsal aspect of area V3, which only contains a lower visual field representation. We examined these proposals by using optical imaging of intrinsic signals to investigate this region in the prosimian galago (Otolemur garnettii). Galagos represent the prosimian radiation of surviving primates; cortical areas that bear strong resemblances across members of primates provide a strong argument for their early origin and conserved existence. Based on our mapping of horizontal and vertical meridian representations, visu...
Data Representations, Transformations, and Statistics for Visual Reasoning
Analytical reasoning techniques are methods by which users explore their data to obtain insight and knowledge that can directly support situational awareness and decision making. Recently, the analytical reasoning process has been augmented through the use of interactive visual representations and tools which utilize cognitive, design and perceptual principles. These tools are commonly referred to as visual analytics tools, and the underlying methods and principles have roots in a variety of disciplines. This chapter provides an introduction to young researchers as an overview of common visual
Summary Crowding is the breakdown in object recognition that occurs in cluttered visual environments [1-4] and the fundamental limit on peripheral vision, affecting identification within many visual modalities [5-9] and across large spatial regions [10]. Though frequently characterized as a disruptive process through which object representations are suppressed [11, 12] or lost altogether [13-15], we demonstrate that crowding systematically changes the appearance of objects. In particular, target patches of visual noise that are surrounded ("crowded") by oriented Gabor flankers become perceptually oriented, matching the flankers. This was established with a change-detection paradigm: under crowded conditions, target changes from noise to Gabor went unnoticed when the Gabor orientation match...
Visual attention to advertising under the influence of alcohol
An eye-tracking experiment is reported in which the effects of alcohol intoxication on visual attention were tested. Based on findings from the psychopharmacological literature, it was hypothesised that the salience of visual elements in complex advertisements would be amplified, whereas the processing of conceptual information would be impaired. The results indicate that the visual salience of logos (either brand and corporate) is selectively increased under the influence of alcohol whilst other pictorial elements (representations of products or human models) are unaffected. Processing of textual elements (headlines, text blocks) is impaired.
Visualization of Force Fields in Protein StructurePrediction
The force fields used in molecular computational biology are not mathematically defined in such a way that their mathematical representation would facilitate the straightforward application of volume visualization techniques. To visualize energy, it is necessary to define a spatial mapping for these fields. Equipped with such a mapping, we can generate volume renderings of the internal energy states in a molecule. We describe our force field, the spatial mapping that we used for energy, and the visualizations that we produced from this mapping. We provide images and animations that offer insight into the computational behavior of the energy optimization algorithms that we employ.
The visual analysis of textual information: Browsing large document sets
Visualization tools have been invaluable in the process of scientific discovery by providing researchers with insights gained through graphical tools and techniques. At PNL, the Multidimensional Visualization and Advanced Browsing (MVAB) project is extending visualization technology to the problems of intelligence analysis of textual documents by creating spatial representations of textual information. By representing an entire corpus of documents as points in a coordinate space of two or more dimensions, the tools developed by the MVAB team give the analyst the ability to quickly browse the entire document base and determine relationships among documents and publication patterns not readily discernible through traditional lexical means.
Effect of spatial sampling on pattern noise in insect-based motion detection
Insects perform highly complicated navigational tasks even though their visual system is relatively simple. The main idea of work in this area is to study the visual system of insects and to incorporate algorithms used by them in electronic circuits to produce low power, computationally simple, highly efficient, robust devices capable of accurate motion detection and velocity estimation. The Reichardt correlator model is one of the earliest and the most prominent biologically inspired models of motion detection developed by Hassentein and Reichardt in 1956. In an attempt to get accurate estimates of yaw velocity using an elaborated Reichardt correlator, we have investigated the effect of pattern noise (deviation of the correlator output resulting from the structure of the visual scene) on the correlator response. We have tested different sampling methods here and it is found that a circular sampled array of elementary motion detectors (EMDs) reduces pattern noise effectively compared to an array of rectangular or randomly selected EMDs for measuring rotational motion.
A Bio-Inspired Flying Robot Sheds Light on Insect Piloting Abilities
SummaryWhen insects are flying forward, the image of the ground sweeps backward across their ventral viewfield and forms an "optic flow," which depends on both the groundspeed and the groundheight. To explain how these animals manage to avoid the ground by using this visual motion cue, we suggest that insect navigation hinges on a visual-feedback loop we have called the optic-flow regulator, which controls the vertical lift. To test this idea, we built a micro-helicopter equipped with an optic-flow regulator and a bio-inspired optic-flow sensor. This fly-by-sight micro-robot can perform exacting tasks such as take-off, level flight, and landing. Our control scheme accounts for many hitherto unexplained findings published during the last 70 years on insects visually guided performances; for...
Disruptive Cartography in Academic Development
Drawing on cartography, urban design and visual data modelling, we consider how people navigate, or fail to navigate, the mental, physical and social spaces of knowledge communities. Cartographically inspired critical thinking offers opportunities to re-examine the assumptions and formal maps of post-secondary institutions, visualizing complexities such as knowledge circulation and ownership, and knowledge seekers' regulated or unregulated traffic. We explore the contrast between the formal view given by typical institutional maps, and the uncovered view shown by maps of collective student activity generated by our prototype visualization tools. We suggest that a critical stance and consultative approaches to institutional mapping might foster collective reflection, empowerment, inquiry and engagement in academic development. (Contains 6 figures.)
Visualizing Energy Data Using Web-Based Applications
I will demonstrate a series of web-based visualizations of domestic state-level and international country-level energy statistics. The time-series energy consumption and production data sets are from the International Energy Agency (IEA) and the United States Department of Energy's Energy Information Administration (EIA). I will demonstrate the capabilities of existing web-based community data analysis sites, such as Swivel.com and IBM's Many-Eyes.com, as well as the capabilities of embeddable visualization gadgets, such as the Gapminder-inspired Motion Charts created by Google. These tools will allow students and the public to interactively explore relationships and trends of energy consumption and production. These visualizations will be particularly useful in exploring energy statistics that are traditionally presented in a multitude of competing units. The tools will also be useful for students in inquiry-based learning programs.
P-363 - Brain activations in relation to cognitive-style
Background: Cognitive-style is a psychological dimension that represents consistencies in how an individual acquires and processes information. It is conceivable that some people are better in processing words, and other people are better in processing images. This basic idea has inspired theories of visual and verbal cognitive-styles. Recently it was shown that a specific pattern of cortex activity distinguishes these two cognitive-styles. Methods: Nine young right-handed healthy adults completed computerized verbal categorization test during fMRI. The test includes three types of conditions: 'MIX': in which each stimulus included 4 word items. one of the four words is functional extraordinary and another one is visual extraordinary. In two other conditions ('FUNCTIONAL' and 'VISUAL') wit...
Beyond Usability: Evaluation Aspects of Visual Analytic Environments
A new field of research, visual analytics, has recently been introduced. This has been defined as “the science of analytical reasoning facilitated by visual interfaces." Visual analytic environments, therefore, support analytical reasoning using visual representations and interactions, with data representations and transformation capabilities, to support production, presentation and dissemination. As researchers begin to develop visual analytic environments, it will be advantageous to develop metrics and methodologies to help researchers measure the progress of their work and understand the impact their work will have on the users who will work in such environments. This paper presents five areas or aspects of visual analytic environments that should be considered as metrics and methodologies for evaluation are developed. Evaluation aspects need to include usability, but it is necessary to go beyond basic usability. The areas of situation awareness, collaboration, interaction, creativity, and utility are proposed as areas for initial consideration. The steps that need to be undertaken to develop systematic evaluation methodologies and metrics for visual analytic environments are outlined.
Most scene segmentation and categorization architectures for the extraction of features in images and patches make exhaustive use of 2D convolution operations for template matching, template search, and denoising. Convolutional Neural Networks (ConvNets) are one example of such architectures that can implement general-purpose bio-inspired vision systems. In standard digital computers 2D convolutions are usually expensive in terms of resource consumption and impose severe limitations for efficient real-time applications. Nevertheless, neuro-cortex inspired solutions, like dedicated Frame-Based or Frame-Free Spiking ConvNet Convolution Processors, are advancing real-time visual processing. These two approaches share the neural inspiration, but each of them solves the problem in different ways. Frame-Based ConvNets process frame by frame video information in a very robust and fast way that requires to use and share the available hardware resources (such as: multipliers, adders). Hardware resources are fixed- and time-multiplexed by fetching data in and out. Thus memory bandwidth and size is important for good performance. On the other hand, spike-based convolution processors are a frame-free alternative that is able to perform convolution of a spike-based source of visual information with very low latency, which makes ideal for very high-speed applications. However, hardware resources need to be available all the time and cannot be time-multiplexed. Thus, hardware should be modular, reconfigurable, and expansible. Hardware implementations in both VLSI custom integrated circuits (digital and analog) and FPGA have been already used to demonstrate the performance of these systems. In this paper we present a comparison study of these two neuro-inspired solutions. A brief description of both systems is presented and also discussions about their differences, pros and cons. PMID:11483297
Four experiments were completed to characterize the utilization of visual imagery and motor imagery during the mental representation of human action. In Experiment 1, movement time functions for a motor imagery human locomotion task conformed to a speed-accuracy trade-off similar to Fitts' Law, whereas those for a visual imagery object motion task did not. However, modality-specific interference effects in Experiment 2 demonstrate visual and motor imagery as cooperative processes when the action represented is tied to visual coordinates in space. Biomechanic-specific motor interference effects found in Experiment 3 suggest one basis for separation of processing channels within motor imagery. Finally, in Experiment 4 representations of motor actions were found to be generated using only visual imagery under certain circumstances: namely, when the imaginer represented the motor action of another individual while placed at an opposing viewpoint. These results suggest that the modality of representation recruited to generate images of human action is dependent on the dynamic relationship between the individual, movement, and environment.
Optimizing Cognitive Load for Learning from Computer-Based Science Simulations
How can cognitive load in visual displays of computer simulations be optimized? Middle-school chemistry students (N = 257) learned with a simulation of the ideal gas law. Visual complexity was manipulated by separating the display of the simulations in two screens (low complexity) or presenting all information on one screen (high complexity). The mode of visual representation in the simulation was manipulated by presenting important information in symbolic form only (symbolic representations) or by adding iconic information to the display (iconic + symbolic representations), locating the sliders controlling the simulation separated from the simulation or integrating them, and graphing either only the most recent simulation result or showing all results taken. Separated screen displays and the use of optimized visual displays each promoted comprehension and transfer, especially for low prior-knowledge learners. An expertise reversal effect was found for learners' prior general science knowledge. Results indicate that intrinsic and extraneous cognitive load in visual displays can be manipulated and that learners' prior knowledge moderates the effectiveness of these load manipulations.
Modelling Cell Cycle using Different Levels of Representation
Understanding the behaviour of biological systems requires a complex setting of in vitro and in vivo experiments, which attracts high costs in terms of time and resources. The use of mathematical models allows researchers to perform computerised simulations of biological systems, which are called in silico experiments, to attain important insights and predictions about the system behaviour with a considerably lower cost. Computer visualisation is an important part of this approach, since it provides a realistic representation of the system behaviour. We define a formal methodology to model biological systems using different levels of representation: a purely formal representation, which we call molecular level, models the biochemical dynamics of the system; visualisation-oriented representations, which we call visual levels, provide views of the biological system at a higher level of organisation and are equipped with the necessary spatial information to generate the appropriate visualisation. We choose Spati...
Flavor A Language for Media Representation
Flavor (Formal Language for Audio-Visual Object Representation) has been created as a language for describing coded multimedia bitstreams in a formal way so that the code for reading and writing bitstreams can be automatically generated. It is an extension of C++ and Java, in which the typing system incorporates bitstream representation semantics. This allows describing in a single place both the in-memory representation of data as well as their bitstream-level (compressed) representation. Flavor also comes with a translator that automatically generates standard C++ or Java code from the Flavor source code so that direct access to compressed multimedia information by application developers can be achieved with essentially zero programming. Flavor has gone through many enhancements and this paper fully describes the latest version of the language and the translator. The software has been made into an open source project as of Version 4.1, and the latest downloadable Flavor package is available at http://flavor...
Hierarchical pose estimation for human gait analysis
Articulated structures like the human body have many degrees of freedom. This makes an evaluation of the configuration's likelihood very challenging. In this work we propose new linked hierarchical graphical models which are able to efficiently evaluate likelihoods of articulated structures by sharing visual primitives. Instead of evaluating all configurations of the human body separately we take advantage of the fact that different configurations of the human body share body parts, and body parts, in turn, share visual primitives. A hierarchical Markov random field is used to integrate the sharing of visual primitives in a probabilistic framework. We propose a scalable hierarchical representation of the human body and show that this representation is especially well suited for human gait ...
Abstract We used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5-years). Visually normal adults and 10-year-olds were tested for comparison. Adults showed the expected opposing aftereffects for upright and inverted faces. Ten-year-olds showed an adultlike aftereffect for upright faces but, unlike the adult group, no aftereffect for inverted faces. Patients failed to show an aftereffect for either upright or inverted faces. Overall, the results suggest that early visual input is necessary for the later development of (at least partially) separable representations of upright and inverted faces...
We used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5 years). Visually normal adults and 10-year-olds were tested for comparison. Adults showed the expected opposing aftereffects for upright and inverted faces. Ten-year-olds showed an adultlike aftereffect for upright faces but, unlike the adult group, no aftereffect for inverted faces. Patients failed to show an aftereffect for either upright or inverted faces. Overall, the results suggest that early visual input is necessary for the later development of (at least partially) separable representations of upright and inverted faces, a developmental process that takes many years to reach an adult-like refinement.
Expertise reversal for iconic representations in science visualizations
The influence of prior knowledge and cognitive development on the effectiveness of iconic representations in science visualizations was examined. Middle and high school students (N?=?186) were given narrated visualizations of two chemistry topics: Kinetic Molecular Theory (Day 1) and Ideal Gas Laws (Day 2). For half of the visualizations, iconic representations of key information were added. Results indicated a main effect of prior knowledge on learning in Day 1. In Day 2, a three-way interaction was found between prior knowledge, age group and icons: icons were effective for all middle school students and for high school students with low prior knowledge, but were not effective for high school students with high prior knowledge. These findings indicate that the expertise reversal effect c...
Where neural information processing is concerned, there is no debate about the fact that spikes are the basic currency for transmitting information between neurons. How the brain actually uses them to encode information remains more controversial. It is commonly assumed that neuronal firing rate is the key variable, but the speed with which images can be analysed by the visual system poses a major challenge for rate-based approaches. We will thus expose here the possibility that the brain makes use of the spatio-temporal structure of spike patterns to encode information. We then consider how such rapid selective neural responses can be generated rapidly through spike-timing-dependent plasticity (STDP) and how these selectivities can be used for visual representation and recognition. Finally, we show how temporal codes and sparse representations may very well arise one from another and explain some of the remarkable features of processing in the visual system. PMID:16275045
Due to an abnormal projection of the temporal retina the albinotic primary visual cortex receives substantial input from the ipsilateral visual field. To test whether representation abnormalities are also evident in higher tier visual, and in motor and somatosensory cortices, brain activity was measured with fMRI in 14 subjects with albinism performing a visuo-motor task. During central fixation, a blue or red target embedded in a distractor array was presented for 250ms in the left or right visual hemifield. After a delay, the subjects were prompted to indicate with left or right thumb button presses the target presence in the upper or lower hemifield. The fMRI responses were evaluated for different regions of interest concerned with visual, motor and somatosensory processing and compared...
Advanced interactive medical visualization on the GPU
Interactive visual analysis of a patient’s anatomy by means of computer-generated 3D imagery is crucial for diagnosis, pre-operative planning, and surgical training. The task of visualization is no longer limited to producing images at interactive rates, but also includes the guided extraction of significant features to assist the user in the data exploration process. An effective visualization module has to perform a problem-specific abstraction of the dataset, leading to a more compact and hence more efficient visual representation. Moreover, many medical applications, such as surgical training simulators and pre-operative planning for plastic and reconstructive surgery, require the visualization of datasets that are dynamically modified or even generated by a physics-based simula...
Visualization of Social Networks
With the ubiquitous characteristic of the Internet, today many online social environments are provided to connect people. Various social relationships are thus created, connected, and migrated from our real lives to the Internet environment from different social groups. Many social communities and relationships are also quickly constructed and connected via instant personal messengers, blogs, Twitter, Facebook, and a great variety of online social services. Since social network visualizations can structure the complex relationships between different groups of individuals or organizations, they are helpful to analyze the social activities and relationships of actors, particularly over a large number of nodes. Therefore, many studies and visualization tools have been investigated to present social networks with graph representations. In this chapter, we will first review the background of social network analysis and visualization methods, and then introduce various novel visualization applications for social networks. Finally, the challenges and the future development of visualizing online social networks are discussed.
Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memo...
Visual representations are central to expert scientific thinking. Meanwhile, novices tend toward narrative conceptions of scientific phenomena. Until recently, however, relationships between visual design, narrative thinking, and their impacts on learning science have only been theoretically pursued. This dissertation first synthesizes different disciplinary perspectives, then offers a mixed-methods investigation into interpretations of scientific representations. Finally, it considers design issues associated with narrative and visual imagery, and explores the possibilities of a pedagogical notation to scaffold the understanding of a standard scientific notation. Throughout, I distinguish two categories of visual media by their relation to narrative: Narrative visual media, which convey content via narrative structure, and Conceptual visual media, which convey states of relationships among objects. Given the role of narrative in framing conceptions of scientific phenomena and perceptions of its representations, I suggest that novices are especially prone to construe both kinds of media in narrative terms. To illustrate, I first describe how novices make meaning of the science conveyed in narrative visual media. Vignettes of an undergraduate student's interpretation of a cartoon about natural selection; and of four 13-year olds' readings of a comic book about human papillomavirus infection, together demonstrate conditions under which designed visual narrative elements facilitate or hinder understanding. I next consider the interpretation of conceptual visual media with an example of an expert notation from evolutionary biology, the cladogram. By combining clinical interview methods with experimental design, I show how undergraduate students' narrative theories of evolution frame perceptions of the diagram (Study 1); I demonstrate the flexibility of symbolic meaning, both with the content assumed (Study 2A), and with alternate manners of presenting the diagram (Study 2B); finally, I show the effects of content assumptions on the diagrams students invent of phylogenetic data (Study 3A), and how first inventing a diagram influences later interpretations of the standard notation (Study 3B). Lastly, I describe the prototype design and pilot test of an interactive diagram to scaffold biology students' understanding of this expert scientific notation. Insights from this dissertation inform the design of more pedagogically useful representations that might support students' developing fluency with expert scientific representations.
Analyzing and Visualizing Whole Program Architectures
This paper describes our work to develop new tool support for analyzing and visualizing the architecture of complete large-scale (millions or more lines of code) programs. Our approach consists of (i) creating a compact, accurate representation of a whole C or C++ program, (ii) analyzing the program in this representation, and (iii) visualizing the analysis results with respect to the program's architecture. We have implemented our approach by extending and combining a compiler infrastructure and a program visualization tool, and we believe our work will be of broad interest to those engaged in a variety of program understanding and transformation tasks. We have added new whole-program analysis support to ROSE [15, 14], a source-to-source C/C++ compiler infrastructure for creating customized analysis and transformation tools. Our whole-program work does not rely on procedure summaries; rather, we preserve all of the information present in the source while keeping our representation compact. In our representation, a million-line application fits in well less than 1 GB of memory. Because whole-program analyses can generate large amounts of data, we believe that abstracting and visualizing analysis results at the architecture level is critical to reducing the cognitive burden on the consumer of the analysis results. Therefore, we have extended Vizz3D [19], an interactive program visualization tool, with an appropriate metaphor and layout algorithm for representing a program's architecture. Our implementation provides developers with an intuitive, interactive way to view analysis results, such as those produced by ROSE, in the context of the program's architecture. The remainder of this paper summarizes our approach to whole-program analysis (Section 2) and provides an example of how we visualize the analysis results (Section 3).
This research investigates the development of symbolic or representational play in two species of the genus "Pan", bonobos ("Pan paniscus") and chimpanzees ("Pan troglodytes"). The participants varied not only by species, but also as to whether they had become proficient in communicating with humans via a set of arbitrary visual symbols, called lexigrams. Using a developmental sequence of representational play based on McCune, we found every level that children manifest to be constructed by "Pan." The most robust and regular ontogenetic sequence for both bonobos and chimpanzee was not McCune's five-level progression, but a three-step ontogenetic sequence: Level 1 (no representation, no pretense) precedes Levels 2-4 (representation but no pretense), which in turn precedes Level 5 (includes pretense as well as representation). A linguistic system for interspecies communication was necessary for Level 5 representational play and "true" pretense. Human scaffolding produced developmental progress within sequences for all the apes, except the bonobo who lacked a system of interspecies communication. This evidence suggests that the potential for representational play and its social stimulation were present in the common ancestor of bonobos, chimpanzees and humans five million years ago.
Drosophila Gene Expression Pattern Annotation Using Sparse Features and Term-Term Interactions.
The Drosophila gene expression pattern images document the spatial and temporal dynamics of gene expression and they are valuable tools for explicating the gene functions, interaction, and networks during Drosophila embryogenesis. To provide text-based pattern searching, the images in the Berkeley Drosophila Genome Project (BDGP) study are annotated with ontology terms manually by human curators. We present a systematic approach for automating this task, because the number of images needing text descriptions is now rapidly increasing. We consider both improved feature representation and novel learning formulation to boost the annotation performance. For feature representation, we adapt the bag-of-words scheme commonly used in visual recognition problems so that the image group information in the BDGP study is retained. Moreover, images from multiple views can be integrated naturally in this representation. To reduce the quantization error caused by the bag-of-words representation, we propose an improved feature representation scheme based on the sparse learning technique. In the design of learning formulation, we propose a local regularization framework that can incorporate the correlations among terms explicitly. We further show that the resulting optimization problem admits an analytical solution. Experimental results show that the representation based on sparse learning outperforms the bag-of-words representation significantly. Results also show that incorporation of the term-term correlations improves the annotation performance consistently. PMID:21614142
Avatars in flux : Blurring the boundaries of a unified phenomenon of bound contours
There is an almost unquestioned consensus in the virtual worlds’ research communities that an avatar is the representation of a user and player in front of the screen and that the relationship between the two predominantly is about identity and self-construal. Richard Bartle’s (2004) influential work and his claim that “it is all about identity” (Ibid: 161) has been widely adopted. In many studies this conception has been explored and substantial contributions have been made (Downs 2010, Filiciak 2003, Fox & Bailenson 2009, Jin & Park 2009, Wang & Chang 2004, and Yee 2006). In this paper, I will, however, question the consensus and conception to suggest that we nuance and broaden our understanding of the relationships of avatars with their owners. The question that I will set out to answer is: In what ways do actors make sense of their choice and design of avatars? The empirical basis for addressing this question is found in iterative video interviews with actors while they act in their chosen virtual worlds and with their avatars. The video interviews have been conducted in situ together with actors on the locations of their usual play and practice – be it at home or at their work place. Over time, when located beside the actors while they act and engage, gradually the conception of an avatar as the representation of an actor has become questionable. The methodological approach of the in situ video interviews is summarized by the notion of “following the actors,” even if it is also recognized that the optic of the researcher is different from that of the engaged actor, who is seen as the expert of his or her engagement and agency. During the interviews, as a researcher sitting beside the actors discussing their relationship with the chosen avatars, increasingly the performative aspects of the relationship has influenced the theoretical understanding explicated by this paper, and it has blurred the boundaries of a seemingly unified phenomenon with bound contours. Thus, a performative phenomenon in flux has emerged and become ever more visible during the in situ studies. Hence, the paper suggests that we nuance our analysis and explicate the multiple and emergent constructions as well as the stabilizing interpretations of the relationships between actor and avatar. Semiotics (Bakhtin 1981, 1993, Nöth 2009, Peirce 1994), and actor-network theory (Latour 1998, 2005, Law 2004) are some of the theoretical references that will assist and enable such analysis. Thus, this paper will discuss how the methodological approach inspired by visual ethnography (Grimshaw 2001, Pink 2001, 2006) and the theoretical analysis of the phenomenon of avatars have mutually constructed and contributed an understanding that emphasizes the multiplicity of the performative phenomenon. Following the methodological reflections and the theoretical analysis, the paper concludes that the relationships of actors and avatars 1) continuously oscillate and change, and they 2) translate and transform the actors and their agencies when enacted and performed. It is suggested that the understanding of avatars as mediators in relations of companionship will help us interpret and understand avatars as a performative phenomenon in flux and with blurred boundaries.
The Tourist Gaze [Urry J, 1990 (Sage, London)] is one of the most discussed and cited tourism books (with about 4000 citations on Google scholar). Whilst wide ranging in scope, the book is known for the Foucault-inspired concept of the tourist gaze that brings out the fundamentally visual and image-saturated nature of tourism encounters. However, some recent literature has critiqued this notion of the ‘tourist gaze’ for reducing tourism to visual experiences—to sightseeing—and neglecting the other senses, bodily experiences, and ‘adventure’. The influential ‘performance turn’ within tourist studies suggests that the doings of tourism are physical or corporeal and not merely visual, and it is necessary to regard ‘performing’ rather than ‘gazing’ as the dominant tourist research paradigm. Yet we argue here that there are, in fact, many similarities between the paradigms of gaze and of performance. They should ‘dance together’ rather than stare at each other at a distance. In this paper we rethink the tourist gaze in the light of this performance turn and of a Goffmanian dramaturgical sociology by examining the embodied and multisensuous nature of gazing as well as the complex social relations and fluid power geometries comprising performances of gazing. The Foucault-inspired notion of the tourist gaze can be enlivened—made more bodily and theatrical—by incorporating Goffman and post-Goffman analyses and aspects of nonrepresentational theory.
Visual Analysis of Weblog Content
In recent years, one of the advances of the World Wide Web is social media and one of the fastest growing aspects of social media is the blogosphere. Blogs make content creation easy and are highly accessible through web pages and syndication. With their growing influence, a need has arisen to be able to monitor the opinions and insight revealed within their content. In this paper we describe a technical approach for analyzing the content of blog data using a visual analytic tool, IN-SPIRE, developed by Pacific Northwest National Laboratory. We highlight the capabilities of this tool that are particularly useful for information gathering from blog data.
At være er at være set : Et visuelt perspektiv på sociale positioner
This article claims that a strengthening of the emphasis on visual embodiment in the analysis of social positions is much needed. It works with the application of an analytic framework inspired by theories of ‘the mimetic faculty' and phenomenological theories of embodiment. This creates a focus on experiences of being seen; experiences of one's ‘seenness'. With an empirical illustrative case, the article shows how this framework makes it possible to address feelings and sensations that are formative of the experience of one's own individual position.
Interdisciplinary Invitations: Exploring Gee's Bend Quilts
Engaging with the quilts of Gee's Bend offers a rich opportunity for students in grades four through eight to develop appreciation for pattern, rhythm, and innovation while learning about history, entrepreneurship, and political activism. By easily accessing print, film, and Internet resources teachers can include these vibrant quilts and quiltmakers in the art classroom for study. This Instructional Resource draws inspiration from several of the Gee's Bend quilts and encourages close examination and thoughtful visual and verbal responses by students. Two interdisciplinary engagements building on students' experiences viewing the quilts and learning about the historical and contemporary context of Gee's Bend are presented in this article. (Contains 7 figures and 3 endnotes.)
Semantic Robot Vision Challenge: Current State and Future Directions
The Semantic Robot Vision Competition provided an excellent opportunity for our research lab to integrate our many ideas under one umbrella, inspiring both collaboration and new research. The task, visual search for an unknown object, is relevant to both the vision and robotics communities. Moreover, since the interplay of robotics and vision is sometimes ignored, the competition provides a venue to integrate two communities. In this paper, we outline a number of modifications to the competition to both improve the state-of-the-art and increase participation.
ViSUS: Visualization Streams for Ultimate Scalability
In this project we developed a suite of progressive visualization algorithms and a data-streaming infrastructure that enable interactive exploration of scientific datasets of unprecedented size. The methodology aims to globally optimize the data flow in a pipeline of processing modules. Each module reads a multi-resolution representation of the input while producing a multi-resolution representation of the output. The use of multi-resolution representations provides the necessary flexibility to trade speed for accuracy in the visualization process. Maximum coherency and minimum delay in the data-flow is achieved by extensive use of progressive algorithms that continuously map local geometric updates of the input stream into immediate updates of the output stream. We implemented a prototype software infrastructure that demonstrated the flexibility and scalability of this approach by allowing large data visualization on single desktop computers, on PC clusters, and on heterogeneous computing resources distributed over a wide area network. When processing terabytes of scientific data, we have achieved an effective increase in visualization performance of several orders of magnitude in two major settings: (i) interactive visualization on desktop workstations of large datasets that cannot be stored locally; (ii) real-time monitoring of a large scientific simulation with negligible impact on the computing resources available. The ViSUS streaming infrastructure enabled the real-time execution and visualization of the two LLNL simulation codes (Miranda and Raptor) run at Supercomputing 2004 on Blue Gene/L at its presentation as the fastest supercomputer in the world. In addition to SC04, we have run live demonstrations at the IEEE VIS conference and at invited talks at the DOE MICS office, DOE computer graphics forum, UC Riverside, and the University of Maryland. In all cases we have shown the capability to stream and visualize interactively data stored remotely at the San Diego Supercomputing Center or monitor in real-time simulation codes executed on a cluster of PC's at LLNL.
Grasping objects with environmentally induced position uncertainty
Presenting simultaneous but spatially discrepant visual and auditory stimuli induces a perceptual translocation of the sound towards the visual input, the ventriloquism effect. General explanation is that vision tends to dominate over audition because of its higher spatial reliability. The underlying neural mechanisms remain unclear. We address this question via a biologically inspired neural network. The model contains two layers of unimodal visual and auditory neurons, with visual neurons having higher spatial resolution than auditory ones. Neurons within each layer communicate via lateral intra-layer synapses; neurons across layers are connected via inter-layer connections. The network accounts for the ventriloquism effect, ascribing it to a positive feedback between the visual and auditory neurons, triggered by residual auditory activity at the position of the visual stimulus. Main results are: i) the less localized stimulus is strongly biased toward the most localized stimulus and not vice versa; ii) amount of the ventriloquism effect changes with visual-auditory spatial disparity; iii) ventriloquism is a robust behavior of the network with respect to parameter value changes. Moreover, the model implements Hebbian rules for potentiation and depression of lateral synapses, to explain ventriloquism aftereffect (that is, the enduring sound shift after exposure to spatially disparate audio-visual stimuli). By adaptively changing the weights of lateral synapses during cross-modal stimulation, the model produces post-adaptive shifts of auditory localization that agree with in-vivo observations. The model demonstrates that two unimodal layers reciprocally interconnected may explain ventriloquism effect and aftereffect, even without the presence of any convergent multimodal area. The proposed study may provide advancement in understanding neural architecture and mechanisms at the basis of visual-auditory integration in the spatial realm. PMID:19834543
Use of Google SketchUp to implement 3D spatio-temporal visualization
Geovisualization is an important means to understand the geographic features and phenomena. Urban space, especially buildings, keeps changing with social development. However, traditional 2D visualization can only represent the plane geometric description, which is unable to support 3D dynamic visualization. Only with 3D dynamic visualization can the buildings' spatial morphology be exhibited temporally, including buildings' creation, expansion, removing, etc. But these buildings' changes are impossible to be studied in traditional 2D and 3D static visualization systems. As a result, it becomes urgent to find an effective solution to implement 3D spatial-temporal visualization of buildings. Inspired by 2D spatial-temporal visualization methods, like snapshot and event-based spatio-temporal data model(ESTDM), we propose a new data model called Spatio-Temporal Page Model(STPM) and implement 3D spatial-temporal visualization in Google SketchUp based on STPM. This paper studies 3D visualization of real estate focusing on its spatio-temporal characteristics. First of all, 3D models are built for every temporal scenario by the Google SketchUp. And every Geo-object is identified by a unique and permanent ObjectID, the linkage of Geo-objects between different time spots. Then, each temporal scenario is represented as page. After having the page series, finally, it is possible to display its spatial-temporal changes and create an animation. Underlying this solution, we have built a prototype system on part of real estate data. It is proven that users are able to understand clearly the real estate's changes from our prototype system. Consequently, we believe our method for 3D spatial-temporal visualization definitely has many merits.
Scientific visualization is the transformation of abstract information into images, and it plays an integral role in the scientific process by facilitating insight into observed or simulated phenomena. Visualization as a discipline spans many research areas from computer science, cognitive psychology and even art. Yet the most successful visualization applications are created when close synergistic interactions with domain scientists are part of the algorithmic design and implementation process, leading to visual representations with clear scientific meaning. Visualization is used to explore, to debug, to gain understanding, and as an analysis tool. Visualization is literally everywhere--images are present in this report, on television, on the web, in books and magazines--the common theme is the ability to present information visually that is rapidly assimilated by human observers, and transformed into understanding or insight. As an indispensable part a modern science laboratory, visualization is akin to the biologist's microscope or the electrical engineer's oscilloscope. Whereas the microscope is limited to small specimens or use of optics to focus light, the power of scientific visualization is virtually limitless: visualization provides the means to examine data that can be at galactic or atomic scales, or at any size in between. Unlike the traditional scientific tools for visual inspection, visualization offers the means to ''see the unseeable.'' Trends in demographics or changes in levels of atmospheric CO{sub 2} as a function of greenhouse gas emissions are familiar examples of such unseeable phenomena. Over time, visualization techniques evolve in response to scientific need. Each scientific discipline has its ''own language,'' verbal and visual, used for communication. The visual language for depicting electrical circuits is much different than the visual language for depicting theoretical molecules or trends in the stock market. There is no ''one visualization too'' that can serve as a panacea for all science disciplines. Instead, visualization researchers work hand in hand with domain scientists as part of the scientific research process to define, create, adapt and refine software that ''speaks the visual language'' of each scientific domain.
The nature of experience determines object representations in the visual system.
Visual perceptual learning (PL) and perceptual expertise (PE) traditionally lead to different training effects and recruit different brain areas, but reasons for these differences are largely unknown. Here, we tested how the learning history influences visual object representations. Two groups were trained with tasks typically used in PL or PE studies, with the same novel objects, training duration and parafoveal stimulus presentation. We observed qualitatively different changes in the cortical representations of these objects following PL and PE training, replicating typical training effects in each field. These effects were also modulated by testing tasks, suggesting that experience interacts with attentional set and that the choice of testing tasks critically determines the pattern of training effects one can observe after a short-term visual training. Experience appears sufficient to account for prior differences in the neural locus of learning between PL and PE. The nature of the experience with an object's category can determine its representation in the visual system. (PsycINFO Database Record (c) 2012 APA, all rights reserved). PMID:22468668
The Role of Visual Representations for Structuring Classroom Mathematical Activity
It is our presupposition that there is still a need for more research about how classroom practices can exploit the use and power of visualization in mathematics education. The aim of this article is to contribute in this direction, investigating how visual representations can structure geometry activity in the classroom and discussing teaching practices that can facilitate students' visualization of mathematical objects. We present one illustrative episode that shows how drawings of geometrical figures have a powerful role in structuring and modifying the mathematical activity in the classroom. It was selected from a database that we have been building to investigate the learning of mathematics in public elementary schools in Brazil. The framework of Activity Theory helped in the characterization of the episode as a system of interconnected activities. We discuss the changes and transformations perceived in those activities; and we explore the idea of miniature cycles of learning actions to focus on the mathematical learning that is taking place. We describe the dynamics and the complexity of the ongoing activity in the calculation of areas; and, how drawings form a part, and show their influence, in it. We argue that part of this influence was associated with the contradiction between abstract mathematical ideas and their empirical representations, revealed by the tensions perceived in the activities analysed; and, simultaneously, that we could see as an impelling force for the learning of the rules and norms which regulate the use of visual representations in school mathematics.
A map of visual space in the primate entorhinal cortex.
Place-modulated activity among neurons in the hippocampal formation presents a means to organize contextual information in the service of memory formation and recall. One particular spatial representation, that of grid cells, has been observed in the entorhinal cortex (EC) of rats and bats, but has yet to be described in single units in primates. Here we examined spatial representations in the EC of head-fixed monkeys performing a free-viewing visual memory task. Individual neurons were identified in the primate EC that emitted action potentials when the monkey fixated multiple discrete locations in the visual field in each of many sequentially presented complex images. These firing fields possessed spatial periodicity similar to a triangular tiling with a corresponding well-defined hexagonal structure in the spatial autocorrelation. Further, these neurons showed theta-band oscillatory activity and changing spatial scale as a function of distance from the rhinal sulcus, which is consistent with previous findings in rodents. These spatial representations may provide a framework to anchor the encoding of stimulus content in a complex visual scene. Together, our results provide a direct demonstration of grid cells in the primate and suggest that EC neurons encode space during visual exploration, even without locomotion. PMID:23103863
After introducing what is known about potential interactions between phonetic/phonological and orthographic representations in first (L1) and second (L2) language speech perception studies, loanword and interphonology, and literacy-related phonological awareness research, the paper describes the case of Japanese learners of French, with particular emphasis on the syllabic/moraic dimension of their interphonology development. We concentrate on French biconsonantal clusters of the Obstruent+Liquid (/r/ and /l/) and /s/+Plosive type. Sixty-two Japanese university students in Japan perform a task of syllabic segmentation of non-words presented in three conditions: auditory, visual and synchronous audiovisual. The results suggest a possible influence of orthography on L2 syllabic representation...
Semantic Reasoning for Scene Interpretation
In this paper, we propose a hierarchical architecture for representing scenes, covering 2D and 3D aspects of visual scenes as well as the semantic relations between the different aspects. We argue that labeled graphs are a suitable representational framework for this representation and demonstrate its potential by two applications. As a first application, we localize lane structures by the semantic descriptors and their relations in a Bayesian framework. As the second application, which is in the context of vision based grasping, we show how the semantic relations can be associated to actions that allow for grasping without using any object knowledge.
Southern Identity in Southern Living Magazine
A fantasy-theme analysis of the editors' letters in Southern Living magazine shows an editorial vision of valuing the past and showcasing unique regional qualities. In addition, a content analysis of the visual representation of race in the magazine's formative years and recent past validates that inhabitants of the region were portrayed overwhelming as white and middle-class, even as affluence among nonwhites has changed. This analysis provides an example of how media products create and proliferate a specific representation of a place and its people. Suggestions for using mass media messages in the classroom to apply geography knowledge and research, as well as media literacy skills, are included.
Southern Identity in "Southern Living" Magazine
A fantasy-theme analysis of the editors' letters in "Southern Living" magazine shows an editorial vision of valuing the past and showcasing unique regional qualities. In addition, a content analysis of the visual representation of race in the magazine's formative years and recent past validates that inhabitants of the region were portrayed overwhelming as white and middle-class, even as affluence among nonwhites has changed. This analysis provides an example of how media products create and proliferate a specific representation of a place and its people. Suggestions for using mass media messages in the classroom to apply geography knowledge and research, as well as media literacy skills, are included. (Contains 6 notes.)
This quasi-experimental study examined 42 high school introductory chemistry students' conceptual understandings of the particulate nature of matter (PNM) before and immediately after instruction. Two groups of students, who were taught by the same teacher, received one of two possible instructional interventions: Reform-Based Teaching (RBT) or Reform-Based Teaching with Multiple Representations (RBTw/MR). The RBTw/MR instruction differed from the RBT instruction in terms of the frequency of using multiple representations (visual, textual, oral) in relationship to the macroscopic phenomenon and the likely actions occurring at the submicroscopic level. Qualitative research methods, including open-ended questionnaires and interviews, were used to investigate and describe participants' concep...
Conversion from Tree to Graph Representation of Requirements
A procedure and software to implement the procedure have been devised to enable conversion from a tree representation to a graph representation of the requirements governing the development and design of an engineering system. The need for this procedure and software and for other requirements-management tools arises as follows: In systems-engineering circles, it is well known that requirements- management capability improves the likelihood of success in the team-based development of complex systems involving multiple technological disciplines. It is especially desirable to be able to visualize (in order to identify and manage) requirements early in the system- design process, when errors can be corrected most easily and inexpensively.
Assessing Spatial Cognition in Stereoscopic Environments
Nineteen middle-school aged students visiting a planetarium were presented with three visuospatial tasks in both 2D (paper) and stereoscopic environments. The students' performance on tasks was evaluated in order to determine the impact of stereoscopic presentation upon accuracy and task completion time. Results show that accuracy did not differ between the two representational environments while completion time was greater for the stereoscopic environment. Post task interviews show that spatial and temporal discontiguity increased the cognitive load. Additionally, the interviews showed that students continued to visualize in two dimensions while using the stereoscopic representations.
Rhetoric, Techne, and the Art of Scientific Inquiry
This article, drawing on Aristotle's concept of techne, develops a framework for exploring rhetoric in the process of scientific inquiry. The Aristotelian “causes” specifically highlight the technical procedures through which scientists carry out their work and the visual representations they deploy to generate meaningful accounts, “bring forth” new findings, and contribute to the existing field of knowledge. The author argues that a techne-based framework makes it possible to maintain a focus on rhetoric as a productive art while broadening the object of rhetorical analysis to include practices and modes of representation that contribute to knowledge production in the physical sciences.
Impact of mental representational systems on design interface.
The purpose of the studies conducted at Argonne National Laboratory is to understand the impact mental representational systems have in identifying how user comfort parameters influence how information is to best be presented. By understanding how each individual perceives information based on the three representational systems (visual, auditory and kinesthetic modalities), it has been found that a different approach must be taken in the design of interfaces resulting in an outcome that is much more effective and representative of the users mental model. This paper will present current findings and future theories to be explored.
Auditory responsive naming versus visual confrontation naming in dementia.
Dysnomia is typically assessed during neuropsychological evaluation through visual confrontation naming. Responsive naming to description, however, has been shown to have a more distributed representation in both fMRI and cortical stimulation studies. While naming deficits are common in dementia, the relative sensitivity of visual confrontation versus auditory responsive naming has not been directly investigated. The current study compared visual confrontation naming and auditory responsive naming in a dementia sample of mixed etiologies to examine patterns of performance across these naming tasks. A total of 50 patients with dementia of various etiologies were administered visual confrontation naming and auditory responsive naming tasks using stimuli that were matched in overall word frequency. Patients performed significantly worse on auditory responsive naming than visual confrontation naming. Additionally, patients with mixed Alzheimer's disease/vascular dementia performed more poorly on auditory responsive naming than did patients with probable Alzheimer's disease, although no group differences were seen on the visual confrontation naming task. Auditory responsive naming correlated with a larger number of neuropsychological tests of executive function than did visual confrontation naming. Auditory responsive naming appears to be more sensitive to effects of increased of lesion burden compared to visual confrontation naming. We believe that this reflects more widespread topographical distribution of auditory naming sites within the temporal lobe, but may also reflect the contributions of working memory and cognitive flexibility to performance. PMID:19626564
Transfer: From the Visual to the Textual in Elena Guro?s Work
The focus of this essay is on the role literary etudes and miniature sketches play in Guro?s work as a whole. I shall ask how the representation of the world around her mediates a distinctive transfer of visual images into verbal images. How does Guro?s visual, and aural attentiveness, as manifested in the fragmentariness of the narration itself, reflect the sensibility of her narrative persona, ???a female flaneur???, who is a modern woman strolling along city streets? A whole taxonomy of sights and discordant sounds forms a ???picture??? of the city street and the city itself. An arsenal of visual signs that Guro?s persona observes signals a transfer from the acoustic to the visual. Guro?s work, moreover, provides numerous examples of the transfer of ???painterly??? devices to poetry...
Electroencephalographic evidence of vector inversion in antipointing
Mirror-symmetrical reaching movements (i.e., antipointing) produce a visual-field-specific pattern of endpoint bias consistent with a perceptual representation of visual space (Heath et al. in Exp Brain Res 192:275???286, 2009a; J Mot Behav 41:383???392 2009b). The goal of the present investigation was to examine the concurrent behavioural and event-related brain potentials (ERP) of pro- and antipointing to determine whether endpoint bias in the latter task is related to a remapping of the environmental parameters of a target (i.e., vector inversion hypothesis) or a shift of visual attention from a veridical to a cognitively represented target location (i.e., reallocation of attention hypothesis). As expected, results for antipointing???but not propointing???yielded a visual-field-specific...
Technology and informal education: what is taught, what is learned.
The informal learning environments of television, video games, and the Internet are producing learners with a new profile of cognitive skills. This profile features widespread and sophisticated development of visual-spatial skills, such as iconic representation and spatial visualization. A pressing social problem is the prevalence of violent video games, leading to desensitization, aggressive behavior, and gender inequity in opportunities to develop visual-spatial skills. Formal education must adapt to these changes, taking advantage of new strengths in visual-spatial intelligence and compensating for new weaknesses in higher-order cognitive processes: abstract vocabulary, mindfulness, reflection, inductive problem solving, critical thinking, and imagination. These develop through the use of an older technology, reading, which, along with audio media such as radio, also stimulates imagination. Informal education therefore requires a balanced media diet using each technology's specific strengths in order to develop a complete profile of cognitive skills. PMID:19119220
Visualizing space, time, and agents: production, performance, and preference.
Visualizations of space, time, and agents (or objects) are ubiquitous in science, business, and everyday life, from weather maps to scheduling meetings. Effective communications, including visual ones, emerge from use in the field, but no conventional visualization form has yet emerged for this confluence of information. The real-world spiral of production, comprehension, and use that fine-tunes communications can be accelerated in the laboratory. Here, we do so in search of effective visualizations of space, time, and agents. Users' production, preference, and performance aligned to favor matrix representations with time as rows or columns and space and agents as entries. Overall, performance and preference were greater for matrices with discrete dots representing cell entries than for matrices with lines, but lines connecting cells may provide an advantage when evaluating temporal sequence. Both the diagram type and the technique have broader applications. PMID:21082213
In this article we consider the implications of using popular visual media as a pedagogic tool for helping teachers acquire critical sociocultural knowledge to work more effectively with students of color, particularly Black males. Drawing from a textual analysis (McKee 2001, 2003; Rose 2001) conducted in the critical visual studies tradition (Barthes 1977; Hall 1993, 1997) and longstanding discourses on Blackness, Black masculinity and critical visual studies, we explore how the critically acclaimed HBO series, "The Wire," positions Black males in the local and larger social milieu. While offering a more complex rendering of the Black male, "The Wire" simultaneously presents a myopic representation of the Black man and his place in the larger Black community. This inquiry highlights the pedagogic limitations of using "The Wire," or any other visual media that reinscribes deficit-oriented knowledge that critical multicultural teacher education seeks to challenge about Blackness and Black people. (Contains 5 notes.)
Three-dimensional visualization analysis for marine field data based on 3D-GIS
Considering large, complex and multi-dimensional marine field data, the general representation and analysis methods based on 2D GIS can not meet the requirements of Ocean Research. For multi-dimensional marine sampling data of sea water properties (ARGO sampling data, ship measured data, etc.), three dimensional interpolation and visual analysis methods can be used to reveal the distribution of sea water properties (such as temperature and salinity), and it is an effective way to detect regional anomaly of marine phenomenon. In order to handle three dimensional sampling data of sea water properties, this paper developed a three dimensional volume visualization analysis GIS component with OpenGL and C++. Three visualization analysis methods are designed and presented, including three-dimensional volume visualization, three dimensional slicing and cutting analysis and three-dimensional contour surface analysis. Example test is conducted, and the test result shows the proposed methods can be effectively used for ocean data analysis.
The Evolution of Developmental Pathways.
The human capacity to recognize complex visual patterns emerges in a sequence of brain areas known as the ventral stream, beginning with primary visual cortex (V1). We develop a population model for mid-ventral processing, in which non-linear combinations of V1 responses are averaged within receptive fields that grow with eccentricity. To test the model, we generate novel forms of visual metamers — stimuli that differ physically, but look the same. We develop a behavioral protocol that uses metameric stimuli to estimate the receptive field sizes in which the model features are represented. Because receptive field sizes change along the ventral stream, the behavioral results can identify the visual area corresponding to the representation. Measurements in human observers implicate V2, providing a new functional account of this area. The model explains deficits of peripheral vision known as “crowding”, and provides a quantitative framework for assessing the capabilities of everyday vision. PMID:10980438
Rapidly Building Visual Management Systems for Context-Aware Services
A component framework for building and operating visual interfaces for context-aware services in ubiquitous computing environments is presented. By using a compound-document technology, it provides physical entities, places, stationary or mobile computing devices, and services with visual components as multimedia representations to enable them to be annotated and controlled them. It can automatically assemble visual components into a visual interface for monitoring and managing context-aware services according to the spatial-containment relationships between their targets in the physical world by using underlying location-sensing systems. End-users can manually deploy and customize context-aware services through user-friendly GUI-based manipulations for editing documents. This paper presents the design for this framework and describes its implementation and practical applications in user/location-aware assistant systems in two museums.
Unsupervised Discovery of Mid-Level Discriminative Patches
The goal of this paper is to discover a set of discriminative patches which can serve as an effective fully unsupervised mid-level visual representation. The desired patches need to satisfy two requirements: 1) to be representative, they need to occur frequently enough in the visual world; 2) to be discriminative, they need to be different enough from the rest of the visual world. The patches could correspond to parts, objects, "visual phrases", etc. but are not restricted to be any one of them (because there is no supervision). We pose this as an unsupervised discriminative clustering problem on a huge dataset of image patches. We use an iterative procedure which alternates between clustering and training discriminative classifiers, while applying careful cross-validation at each step to prevent overfitting. The resulting clusters/detectors are then ranked to find the most representative and discriminative ones. Given the discriminative patch clusters, we also discover "doublets" -- pairs of spatially co-occ...
This study examined whether inspecting and constructing different part-task-specific visualizations differentially affects learning. To this end, a complex business-economics problem was structured into three phase-related part-tasks: (1) determining core concepts, (2) proposing multiple solutions, and (3) coming to a single solution. Each phase was foreseen with a part-task-specific representational tool facilitating visualization of the domain-content (i.e., a conceptual, causal and simulation tool respectively for the subsequent phases). Whereas all teams of learners (N = 17) were scripted to carry out the part-tasks in the predefined order, teams were instructed to (1) inspect expert visualizations (n = 8) or (2) construct their own domain-specific visualizations (n = 9). Results indic...
Alerts Visualization and Clustering in Network-based Intrusion Detection
Today's Intrusion detection systems when deployed on a busy network overload the network with huge number of alerts. This behavior of producing too much raw information makes it less effective. We propose a system which takes both raw data and Snort alerts to visualize and analyze possible intrusions in a network. Then we present with two models for the visualization of clustered alerts. Our first model gives the network administrator with the logical topology of the network and detailed information of each node that involves its associated alerts and connections. In the second model, flocking model, presents the network administrator with the visual representation of IDS data in which each alert is represented in different color and the alerts with maximum similarity move together. This gives network administrator with the idea of detecting various of intrusions through visualizing the alert patterns.
Digital media Experiences for Visual Learning
Visual learning is a topic for didactic studies in all levels of educaion, brought about by an increasing use of digital meida- digital media give rise to discussions of how learning expereienes come about from various media ressources that generate new learning situations. new situations call for new tools and new theoretical approaches with which to understand them. the article argues that the current phase of social practices and technological development makes it difficult to disitnguish between experience with digital media and mediated experiences, because of the use of renegotiation og both possibilites of technology and the nature of the content it facilitates. the discussion comes in three parts: 1. the alteration of visual representations in contemporary teaching and learning brought about by digital interfaces, 2. the functions af visual experience in learning processes brought about by the nature of diverse digital artefacts, 3. the learning potentials in using mobils devices for integrating thebody in visual perception processes.
A 16 pixel yaw sensor for velocity estimation
The insect visual system, with its simplicity and efficiency has gained widespread attention and many biologically inspired models are being used for motion detection and velocity estimation tasks. One of the earliest and most efficient models among them is the Reichardt correlator model. In this paper, we have elaborated the basic Reichardt correlator to include spatial and temporal pre-filtering and additional non-linearites which are believed to be present in the fly visual system to develop a simple yaw sensor. We have used just 16 elaborated EMDs and it is seen that this sensor can detect rotational motion at angular velocities up to several thousand degrees per second. The modelling of these sensors make us realize that the VLSI implementation of such simple detectors can have varied applications for flight control in different fields.
The Planeterrella experiment: from individual initiative to networking
Space weather is a relatively new discipline which is generally unknown to the wider public, despite its increasing importance to all of our daily lives. Outreach activities can help in promoting the concept of space weather. In particular the visual beauty and excitement of the aurora make these lights a wonderful inspirational hook. A century ago Norwegian experimental physicist Kristian Birkeland, one of the founding fathers of modern space science, demonstrated with his Terrella experiment the formation of the aurora. Recently a modernised version of the Terrella has been designed. This Planeterrella experiment is very flexible, allowing the visualization of many phenomena occurring in our space environment. Although the Planeterrella was originally designed to be small to be demonstrated locally by a scientist, the Planeterrella has proved to be a very successful public outreach experiment. We believe that its success is due to two main factors (i) the Planeterrella is not patented and the plans are give...
Visual data mining of multimedia data for social and behavioral studies
With advances in computing techniques, a large amount of high-resolution high-quality multimedia data (video and audio, and so on) has been collected in research laboratories in various scientific disciplines, particularly in cognitive and behavioral studies. How to automatically and effectively discover new knowledge from rich multimedia data poses a compelling challenge because most state-of-the-art data mining techniques can only search and extract pre-defined patterns or knowledge from complex heterogeneous data. In light of this challenge, we propose a hybrid approach that allows scientists to use data mining as a first pass, and then forms a closed loop of visual analysis of current results followed by more data mining work inspired by visualization, the results of which can be in tu...
An immersive path-based study of wind turbines' landscape: A French case in Plouguin
Wind turbines (WT) are socially controversial because of their visual and acoustic impacts. Today, visual impact is studied through photomontages and virtual environments while acoustic impact is rather evaluated through technical studies. This paper aims to study the landscape of WT in situ using an immersive path-based method in which the observer is directly interacting with the environment. In order to evaluate the assets of such a method, first a non-immersive survey based on interviews is performed. Then, the immersive study, the "commented country walks" inspired from an urban space description method, combines pedestrian's perception and motion in order to characterize and contextualize impacts. The study of two different paths - corresponding to the immediate and the intermediate ...
Visualization of large scale geologically related data in virtual 3D scenes with OpenGL
This paper demonstrates a method for three-dimensional (3D) reconstruction and visualization of large scale multidimensional surficial, geological and mine planning data with the programmable visualization environment OpenGL. A simulation system developed by the authors is presented for importing, filtering and visualizing of multidimensional geologically related data. The approach for the visual simulation of complicated mining engineering environment implemented in the system is described in detail. Aspects like presentations of multidimensional data with spatial dependence, navigation in the surficial and geological frame of reference and in time, interaction techniques are presented. The system supports real 3D landscape representations. Furthermore, the system provides many visualization methods for rendering multidimensional data within virtual 3D scenes and combines them with several navigation techniques. Real data derived from an iron mine in Wuhan City of China demonstrates the effectiveness and efficiency of the system. A case study with the results and benefits achieved by using real 3D representations and navigations of the system is given.
Photographical History, Everyday Life, and Memory: Wang Anyi as a Storyteller
Abstract Postmodernists view all reality as representation and visual spectacle. This essay challenges this claim through film analysis of third world cinema and by tracing the tension between photography and history to the earlier debate of modernity in Siegfried Kracauer's work. The essay goes on to show the possibility of historically grounded visual images. By looking at the Chinese novelist Wang Anyi's photo narratives, the essay argues for a photographical image capable of fostering a sense of history deeply rooted in everyday life, communal practice, and social reality. Instead of being the inauthentic mirror of consumer culture, the photographical image is integral to historical imagination, narratives of everyday practice, and cultural memory.
Neural Mechanisms of Short-term Plasticity in the Human Visual System
Following circumscribed retinal damage, extensive reorganization of topographically organized visual cortical areas has been demonstrated in several species of mammals (including humans). Although reorganization is often studied over extended time scales, neural response properties change within seconds of retinal deafferentation. Understanding the mechanisms underlying these short-term effects is essential for developing a complete picture of representational plasticity. One approach to the study of short-term plasticity has been to use an artificial scotoma, a stimulus-induced analog of a retinal scotoma, as a model. Here, we use event-related potentials in an artificial scotoma paradigm to examine 2 aspects of short-term plasticity in the human visual system. First, we investigated the ...
Memory for objects helps us to determine how we can most effectively and appropriately interact with them. This suggests a tightly coupled interplay between action and background knowledge. Three experiments demonstrate that grasping circumference can be affected by the size of a visual stimulus (Experiment 1), whether that stimulus appears to be graspable (Experiment 2), and the presence of a label that renders that object ungraspable (Experiment 3). The results are taken to inform theories on conceptual representation and the functional distinction that has been drawn between the visual systems for perception and action. (Contains 5 figures.)
Perceptual geometry refers to the interdisciplinary research whose objectives focuses on study of geometry from the perspective of visual perception, and in turn, applies such geometric findings to the ecological study of vision. Perceptual geometry attempts to answer fundamental questions in perception of form and representation of space through synthesis of cognitive and biological theories of visual perception with geometric theories of the physical world. Perception of form, space and motion are among fundamental problems in vision science. In cognitive and computational models of human perception, the theories for modeling motion are treated separately from models for perception of form.
Learning to Attend and to Ignore Is a Matter of Gains and Losses
ABSTRACT Efficient goal-directed behavior in a crowded world is crucially mediated by visual selective attention (VSA), which regulates deployment of cognitive resources toward selected, behaviorally relevant visual objects. Acting as a filter on perceptual representations, VSA allows preferential processing of relevant objects and concurrently inhibits traces of irrelevant items, thus preventing harmful distraction. Recent evidence showed that monetary rewards for performance on VSA tasks strongly affect immediately subsequent deployment of attention; a typical aftereffect of VSA (negative priming) was found only following highly rewarded selections. Here we report a much more striking demonstration that the controlled delivery of monetary rewards also affects attentional processing sever...
Mensurações em ciência/ Measurements in science
Abstract in portuguese A natureza da mensuração, terminologias e importância de seus usos em ciência são comentados quanto a sistemas numéricos, representações logarítmicas, unidades (com aplicações a medidas do índice de refração, acuidade visual e ângulos), ordens de grandeza, escalas, sensibilidades, leituras e interpolações, algarismos significativos, precisão e exatidão, fidedignidade e significância (clínica e estatística). Abstract in english The nature of mensurations, terminologies and the importance of their uses are commented regarding numerical systems, logarithmic representations, units (with applications to measurements of the index of refraction, visual acuity and angles), orders of magnitude, scales, sensitivity, instrumental readings and interpolations, significant digits, precision and accuracy, reliability and significance (clinical and statistical).
The many facets of facial interactions in mammals
Facial interactions are prominent behaviors in primates. Primate facial signaling, which includes the expression of emotions, mimicking of facial movements, and gaze interactions, is visually dominated. Correspondingly, in primate brains an elaborate network of face processing areas exists within visual cortex. But other mammals also communicate through facial interactions using additional sensory modalities. In rodents, multisensory facial interactions are involved in aggressive behaviors and social transmission of food preferences. The eusocial naked mole-rat, whose face is dominated by prominent incisors, uses facial aggression to enforce reproductive suppression. In burrow-living mammals like the naked mole-rat in particular, and in rodents in general, somatosensory face representation...
Connectionist models and parallelism in high-level vision. Technical report
Students of human and machine vision share the belief that massively parallel processing characterizes early vision. For higher levels of visual organization, considerably less is known and there is much less agreement about the best computational view of the processing. This paper lays out a computational framework in which all levels of vision can be naturally carried out in highly parallel fashion. One key is the representation of all visual information needed for high-level processing as discrete parameter values that can be represented by units. Two problems that appear to require sequential attention are described and their solutions within the basically parallel structure are presented. Some simple program results are included.
Egocentric/allocentric and coordinate/categorical haptic encoding in blind people
In this research, the impact of visual experience on the capacity to use egocentric (body-centered) and allocentric (object-centered) representations in combination with categorical (invariant non-metric) and coordinate (variable metric) spatial relations was examined. Participants memorized through haptic (congenitally blind, adventitiously blind, and blindfolded) and haptic + visual (sighted) exploration triads of 3D objects and then they were asked to judge: ?which object was closest/farthest to you?? (egocentric-coordinate); ?which object was on your left/right?? (egocentric-categorical); ?which object was closest/farthest to a target object (e.g., cone)?? (allocentric-coordinate); ?which object was on the left/right of the target object (e.g., cone)?? (allocentric-categorical). The re...
Children's Play in the Visual Arts and Literature
Throughout history, society has expressed little interest in early childhood play. Still early literature authors and classical paintings portray childhood play experiences. The way play has been conceived in the past in child development, psychology and other disciplines relates to contemporary early childhood programmes. This article provides an historical overview of the way literature and the visual arts depict play. The early pioneers and historical representations of children's play are briefly discussed to help us understand the way play was portrayed in literature and the visual arts.
Where are Bottlenecks in NK Fitness Landscapes?
Usually the offspring-parent fitness correlation is used to visualize and analyze some caracteristics of fitness landscapes such as evolvability. In this paper, we introduce a more general representation of this correlation, the Fitness Cloud (FC). We use the bottleneck metaphor to emphasise fitness levels in landscape that cause local search process to slow down. For a local search heuristic such as hill-climbing or simulated annealing, FC allows to visualize bottleneck and neutrality of landscapes. To confirm the relevance of the FC representation we show where the bottlenecks are in the well-know NK fitness landscape and also how to use neutrality information from the FC to combine some neutral operator with local search heuristic.
Spatial Aggregation Theory and Applications
Visual thinking plays an important role in scientific reasoning. Based on the research in automating diverse reasoning tasks about dynamical systems, nonlinear controllers, kinematic mechanisms, and fluid motion, we have identified a style of visual thinking, imagistic reasoning. Imagistic reasoning organizes computations around image-like, analogue representations so that perceptual and symbolic operations can be brought to bear to infer structure and behavior. Programs incorporating imagistic reasoning have been shown to perform at an expert level in domains that defy current analytic or numerical methods. We have developed a computational paradigm, spatial aggregation, to unify the description of a class of imagistic problem solvers. A program written in this paradigm has the following properties. It takes a continuous field and optional objective functions as input, and produces high-level descriptions of structure, behavior, or control actions. It computes a multi-layer of intermediate representations, c...
Effects of Multimodal Information on Learning Performance and Judgment of Learning
Two experiments were conducted to investigate the effects of multimodal information on learning performance and judgment of learning (JOL). Experiment 1 examined the effects of representation type (word-only versus word-plus-picture) and presentation channel (visual-only versus visual-plus-auditory) on recall and immediate-JOL in fixed-rate learning conditions. Experiment 2 examined the effects of representation type (word-only versus word-plus-picture) and presentation media (computer versus paper) on recall and delayed-JOL in self-paced learning conditions. The results showed that recall performance was better in word-only conditions than in word-plus-picture conditions in Experiment 1, and better in computer conditions than in paper conditions in Experiment 2. Multimodal information had no influence on magnitude of people's judgment. Participants were overconfident in all conditions, but more overconfident in computer conditions than in paper conditions. (Contains 2 tables.)
Visual knowledge representation of conceptual semantic networks
This article presents methods of using visual analysis to visually represent large amounts of massive, dynamic, ambiguous data allocated in a repository of learning objects. These methods are based on the semantic representation of these resources. We use a graphical model represented as a semantic graph. The formalization of the semantic graph has been intuitively built to solve a real problem which is browsing and searching for lectures in a vast repository of colleges/courses located at Western Kentucky University ( External Reference Not Shown ). This study combines Formal Concept Analysis (FCA) with Semantic Factoring to decompose complex, vast concepts into their primitives in order to develop knowledge representation for the HyperManyMedia [we proposed this term to refer to any educ...
Learning Objects and Grasp Affordances through Autonomous Exploration
We describe a system for autonomous learning of visual object representations and their grasp affordances on a robot-vision system. It segments objects by grasping and moving 3D scene features, and creates probabilistic visual representations for object detection, recognition and pose estimation, which are then augmented by continuous characterizations of grasp affordances generated through biased, random exploration. Thus, based on a careful balance of generic prior knowledge encoded in (1) the embodiment of the system, (2) a vision system extracting structurally rich information from stereo image sequences as well as (3) a number of built-in behavioral modules on the one hand, and autonomous exploration on the other hand, the system is able to generate object and grasping knowledge through interaction with its environment.
Eliciting Subjective Probabilities in Internet Surveys
Individuals' subjective expectations are important in explaining heterogeneity in individual choices, but their elicitation poses some challenges, in particular when one is interested in the subjective probability distribution of an individual. We have developed an innovative visual representation for Internet surveys that has some advantages over previously used formats. In this paper we present our findings from testing this visual representation in the context of individuals' Social Security expectations. Respondents are asked to allocate a total of 20 balls across seven bins to express what they believe the chances to be that their future Social Security benefits would fall into any one of those bins. Our data come from the Internet survey of respondents to the Health and Retirement St...
Characterizing virtual slide exploration through the use of 'search maps'
Currently very little is known about the process by which pathologists arrive at a diagnosis on a case. This process is an integration of the pathologist's slide exploration strategy, perceptual information gathering and cognitive decision making. We have developed a methodology to statically represent the pathologists' dynamic visual search of digital slides by creating a representation of visual sampling called 'search maps'. In these maps slide exploration is divided into three parts, according to the magnification range used. In other words, areas explored at low magnification (4x-10x) and high magnification (>10x-20x) are represented separately. Moreover, representation using the 'search maps' allows for quantitative analysis and pairwise comparison of slide exploration strategy. In this paper we have compared the search maps of experienced pathologists and those of Pathology residents. Our goal was to understand how search differs between the experts and the trainees.
Visual force feedback in laparoscopic training
Background To improve endoscopic surgical skills, an increasing number of surgical residents practice on box or virtual reality (VR) trainers. Current training is focused mainly on hand???eye coordination. Training methods that focus on applying the right amount of force are not yet available. Methods The aim of this project is to develop a low-cost training system that measures the interaction force between tissue and instruments and displays a visual representation of the applied forces inside the camera image. This visual representation continuously informs the subject about the magnitude and the direction of applied forces. To show the potential of the developed training system, a pilot study was conducted in which six novices performed a needle-driving task in a box trainer with visua...
Clustering techniques for personal photo album management
We propose a novel approach for the automatic representation of pictures achieving a more effective organization of personal photo albums. Images are analyzed and described in multiple representation spaces, namely, faces, background, and time of capture. Faces are automatically detected, rectified, and represented, projecting the face itself in a common low-dimensional eigenspace. Backgrounds are represented with low-level visual features based on an RGB histogram and Gabor filter bank. Faces, time, and background information of each image in the collection is automatically organized using a mean-shift clustering technique. Given the particular domain of personal photo libraries, where most of the pictures contain faces of a relatively small number of different individuals, clusters tend to be semantically significant besides containing visually similar data. We report experimental results based on a data set of about 1000 images where automatic detection and rectification of faces lead to approximately 400 faces. Significance of clustering has been evaluated, and results are very encouraging.
We investigated distractor processing in a dual-target rapid serial visual presentation (RSVP) task containing familiar objects, by measuring repetition priming from a priming distractor (PD) to Target 2 (T2). Priming from a visually identical PD was contrasted with priming from a PD in a different orientation from T2. We also tested the effect of attention on distractor processing, by placing the PD either within or outside the attentional blink (AB). PDs outside the AB induced positive priming when they were in a different orientation to T2 and no priming, or negative priming, when they were perceptually identical to T2. PDs within the AB induced positive priming regardless of orientation. These findings demonstrate (1) that distractors are processed at multiple levels of representation; (2) that the view-specific representations of distractors are actively suppressed during RSVP; and (3) that this suppression fails in the absence of attention. (Contains 4 footnotes and 8 figures.)
A Bayes-Maximum Entropy method for multi-sensor data fusion
In this paper we introduce a Bayes-Maximum Entropy formalism for multi-sensor data fusion, and present an application of this methodology to the fusion of ultrasound and visual sensor data as acquired by a mobile robot. In our approach the principle of maximum entropy is applied to the construction of priors and likelihoods from the data. Distances between ultrasound and visual points of interest in a dual representation are used to define Gibbs likelihood distributions. Both one- and two-dimensional likelihoods are presented, and cast into a form which makes explicit their dependence upon the mean. The Bayesian posterior distributions are used to test a null hypothesis, and Maximum Entropy Maps used for navigation are updated using the resulting information from the dual representation. 14 refs., 9 figs.
EMP (electromagnetic pulse) representational tools for personal workstations
The ability to rapidly provide a visual representation of a problem set, its accompanying environment, and the variables that directly impact the analysis is of enormous value to the weapons analyst. Parametric, first-principle tools are directly and immediately usable by the analyst to represent the systems under investigation and the effects on those systems by the weapons under analysis. The three tools described, GEOREP, 3-AXIS, and G RANGE, provide these visual, analytic tools directly to the analyst on personal computer workstations. The simplicity and rapidity with which these tools may be used are especially beneficial to weapons analysts dealing with complex phenomena such as EMP. The potential flexibility of these representational tools is shown through examples of notional weapons applications. Use of GEOREP, 3-AXIS, and G RANGE, which augment, rather than supplant, complex weapons effects physics codes, can help provide the necessary, cost-effective guidance for making decisions on detailed case studies.
Visual classification with multitask joint sparse representation.
We address the problem of visual classification with multiple features and/or multiple instances. Motivated by the recent success of multitask joint covariate selection, we formulate this problem as a multitask joint sparse representation model to combine the strength of multiple features and/or instances for recognition. A joint sparsity-inducing norm is utilized to enforce class-level joint sparsity patterns among the multiple representation vectors. The proposed model can be efficiently optimized by a proximal gradient method. Furthermore, we extend our method to the setup where features are described in kernel matrices. We then investigate into two applications of our method to visual classification: 1) fusing multiple kernel features for object categorization and 2) robust face recognition in video with an ensemble of query images. Extensive experiments on challenging real-world data sets demonstrate that the proposed method is competitive to the state-of-the-art methods in respective applications. PMID:22736645
Given that astronomy heavily relies on visual representations it is especially likely for individuals to assume that instructional materials, such as visual representations of the Earth-Moon system (EMS), would be relatively accurate. However, in our research, we found that images in middle-school textbooks and educational webpages were commonly inaccurate in both: (a) the relative size of the Earth and Moon and (b) the relative distance between the Earth and Moon. More specifically, the students' estimates, textbook images, and web images of the relative "size" of the Moon were too large, and of the relative "distance" were too small. We discuss these findings and provide recommendations to science educators. (Contains 5 figures and 3 tables.)
Diagrams and Proofs in Analysis
The article discusses the role of diagrams in mathematical reasoning based on a case study in analysis. In the presented example certain combinatorial expressions were first found by using diagrams. In the published proofs the pictures are replaced by reasoning about permutation groups. This paper argues that, even though the diagrams are not present in the papers, they still play a role in the formulation of the proofs. It is shown that they play a role in concept formation as well as representations of proofs. In addition we note that `visualizaton' is used in different ways. In the first sense visualization denotes our inner mental pictures, which enables us to see that a certain fact holds, whereas in the other sense, `visualization' denotes a diagram or representation of something.
Music in dreams and the emergence of the self.
This paper deals with the presence and possible 'meaning' of music in dreams. The author explores a possible meaning of music as the most fundamental human symbolic experience, which directly points to the emergence of the Self from the primal union mystique with the Great Mother. The relationships between acoustic and visual experiences are taken into account as two basic human forms of coming into existence, although wholly different from each other. The role of music in dreams seems to be that of the most direct representation of the emerging Self in its pure, pre-representational form. Therefore, when music appears in dreams, providing there is the activation of an emotional tone, all other elements--visual and verbal--should be considered as the expression of the sense to which the music is pointing. A clinical example is described in order to better express the author's opinions. PMID:19161518
Combining Attention Model with Hierarchical Graph Representation for Region-Based Image Retrieval
The manifold-ranking algorithm has been successfully adopted in content-based image retrieval (CBIR) in recent years. However, while the global low-level features are widely utilized in current systems, region-based features have received little attention. In this paper, a novel attention-driven transductive framework based on a hierarchical graph representation is proposed for region-based image retrieval (RBIR). This approach can be characterized by two key properties: (1) Since the issue about region significance is the key problem in region-based retrieval, a visual attention model is chosen here to measure the regions' significance. (2) A hierarchical graph representation which combines region-level with image-level similarities is utilized for the manifold-ranking method. A novel propagation energy function is defined which takes both low-level visual features and regional significance into consideration. Experimental results demonstrate that the proposed approach shows the satisfactory retrieval performance compared to the global-based and the block-based manifold-ranking methods.
A Reference Based Analysis Framework for Analyzing System Call Traces
Reference based analysis (RBA) is a novel data mining tool for exploring a test data set with respect to a reference data set. The power of RBA lies in it ability to transform any complex data type, such as symbolic sequences and multi-variate categorical data instances, into a multivariate continuous representation. The transformed representation not only allows visualization of the complex data, which cannot be otherwise visualized in its original form, but also allows enhanced anomaly detection in the transformed feature space. We demonstrate the application of the RBA framework in analyzing system call traces and show how the transformation results in improved intrusion detection performance over state of art data mining based intrusion detection methods developed for system call traces.
Slowness and sparseness lead to place, head-direction, and spatial-view cells.
We present a model for the self-organized formation of place cells, head-direction cells, and spatial-view cells in the hippocampal formation based on unsupervised learning on quasi-natural visual stimuli. The model comprises a hierarchy of Slow Feature Analysis (SFA) nodes, which were recently shown to reproduce many properties of complex cells in the early visual system []. The system extracts a distributed grid-like representation of position and orientation, which is transcoded into a localized place-field, head-direction, or view representation, by sparse coding. The type of cells that develops depends solely on the relevant input statistics, i.e., the movement pattern of the simulated animal. The numerical simulations are complemented by a mathematical analysis that allows us to accurately predict the output of the top SFA layer. PMID:17784780
Cortical representation of animate and inanimate objects in complex natural scenes
The representations of animate and inanimate objects appear to be anatomically and functionally dissociated in the primate brain. How much of the variation in object-category tuning across cortical locations can be explained in terms of the animate/inanimate distinction? How is the distinction between animate and inanimate reflected in the arrangement of object representations along the cortical surface? To investigate these issues we recorded BOLD activity in visual cortex while subjects viewed streams of natural scenes. We then constructed an explicit model of object-category tuning for each voxel along the cortical surface. We verified that these models accurately predict responses to novel scenes for voxels located in anterior visual areas, and that they can be used to accurately decod...
Implicit body representations and the conscious body image
Recent studies have revealed that somatosensory processing relies on a class of implicit body representations showing large distortions of size and shape. The relation between these representations and the conscious body image remains unclear. Dissociations have been reported in the clinical literature on eating disorders between different body image measures, with larger and more consistent distortions found with depictive measures, in which participants compare their body to a visual depiction of a body, than metric measures, in which participants compare their body to some non-body standard. Here, we compared implicit body representations underlying position sense to the body image measured with both depictive and metric methods. The body image was measured using both a depictive method...
Lexical processing in Spanish Sign Language (LSE)
Lexical access is concerned with how the spoken or visual input of language is projected onto the mental representations of lexical forms. To date, most theories of lexical access have been based almost exclusively on studies of spoken languages and/or orthographic representations of spoken languages. Relatively few studies have examined how lexical access takes place in deaf users of signed languages. This paper examines whether two properties, lexical familiarity and phonological neighborhood, which are known to influence recognition in spoken languages, influence lexical access in Spanish Sign Language-Lengua de Signos Espanola (LSE). Our results indicate that the representational factors of lexical familiarity and phonological neighborhood can be observed in native and non-native deaf ...
David Melcher: Award for Distinguished Scientific Early Career Contributions to Psychology.
Presents David Melcher, the 2011 winner of the American Psychological Association Award for Distinguished Scientific Early Career Contributions to Psychology. "For his elegant and groundbreaking work on one of the most important problems in perceptual psychology, the transfer of perceptual representations across eye movements. David Melcher's innovative experiments used perceptual aftereffects to show how remapping of visual locations underlies the creation of the percept of a clear and stable world. His work on the accumulation of memory contributed importantly to the understanding of natural perceptual representations and their neural underpinnings. His elegant reviews of transsaccadic perception communicated to a broad audience the remarkable capacity of the brain to create seamless perceptual representations despite the disruptions produced by eye movements." (PsycINFO Database Record (c) 2011 APA, all rights reserved). PMID:22082390
We investigated cortical activity in response to abstract and representational paintings in artists and non-artists. Participants engaged in visual inspection of works of art and recalled them immediately afterwards through mental imagery. Meanwhile, we recorded their EEG, and calculated the power of their alpha band and theta band activity afterwards. In accordance with previous studies, theta band and alpha band power differed between artists and non-artists; these differences were found to depend, however, on the abstract or representational character of the paintings. Differences between abstract and representational art, and between inspection and imagery, occurred in alpha band power for non-artists only and in theta band power for artists. These results were taken to suggest that effects in artists reflect sustained focused attention and perceptual flexibility; in non-artists motivation and engagement with the task. The results were essentially whole-head, despite the local character of the measurement. PMID:21425703
Spatial cognition is the ability to reason about geometric relationships in the real (or a metaphorical) world based on one or more internal representations of those relationships. The study of spatial cognition is concerned with the representation of spatial knowledge, and our ability to manipulate these representations to solve spatial problems. Spatial cognition is utilized most critically when direct perceptual cues are absent or impoverished. Examples are provided of how human spatial cognitive abilities impact on three areas of space station operator performance: orientation, path planning, and data base management. A videotape provides demonstrations of relevant phenomena (e.g., the importance of orientation for recognition of complex, configural forms). The presentation is represented by abstract and overhead visuals only.
A High Quality Text-To-Speech System Composed of Multiple Neural Networks
While neural networks have been employed to handle several different text-to-speech tasks, ours is the first system to use neural networks throughout, for both linguistic and acoustic processing. We divide the text-to-speech task into three subtasks, a linguistic module mapping from text to a linguistic representation, an acoustic module mapping from the linguistic representation to speech, and a video module mapping from the linguistic representation to animated images. The linguistic module employs a letter-to-sound neural network and a postlexical neural network. The acoustic module employs a duration neural network and a phonetic neural network. The visual neural network is employed in parallel to the acoustic module to drive a talking head. The use of neural networks that can be retrained on the characteristics of different voices and languages affords our system a degree of adaptability and naturalness heretofore unavailable.
Suppression of premotor cortex disrupts motor coding of peripersonal space
Peripersonal space (PPS) representation depends on the activity of a fronto-parietal network including the premotor cortex (PMc) and the posterior parietal cortex (PPc). PPS representation has a direct effect on the motor system: a stimulus activating the PPS around the hand modulates the excitability of hand representation in the primary motor cortex. However, to date, direct information about the involvement of the PMc-PPc network in the motor mapping of sensory events occurring within PPS is lacking. To address this issue, we used a 'perturb-and-measure' paradigm based on the combination of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) techniques. Cathodal tDCS was applied to transiently suppress neural activity in PMc, PPc and primary visual...
A body-part-specific impairment in the visual recognition of actions in chronic pain patients
Most people suffer musculoskeletal pain sometime in their lives. Although the pain usually disappears with the healing, it may become chronic. Recent evidence suggests that high-level cortical representations play a role in chronic pain. Here we hypothesized that the sensorimotor representations of the affected body parts are specifically inhibited with chronic pain. Thus, if these representations are not accessible for the actions performed by one's own body, neither should they be for the perception of actions performed by others. Chronic pain patients are often focused on possibly painful movements, but visual processes are not affected by chronic pain, so we expected that patients should have no problems recognizing point-light biological motion displays, but should be unable to extrac...
Critical Infrastructures as Complex Systems: A Multi-level Protection Architecture
This paper describes a security platform as a complex system of holonic communities, that are hierarchically organized, but self-reconfigurable when some of them are detached or cannot otherwise operate. Furthermore, every possible subset of holons may work autonomously, while maintaining self-conscience of its own mission, action lines and goals. Each holonic unit, either elementary or composite, retains some capabilities for sensing (perception), transmissive apparatus (communication), computational processes (elaboration), authentication/authorization (information security), support for data exchange (visualization & interaction), actuators (mission), ambient representation (geometric reasoning), knowledge representation (logic reasoning), situation representation and forecasting (simulation), intelligent feedback (command & control). The higher the organizational level of the holonic unit, the more complex and sophisticated each of its characteristic features.
Attention and encoding in physics learning and problem solving
This dissertation presents several studies designed to probe the mental representations that physics experts and novices form when interacting with typical instructional materials, such as diagrams and problem statements. By using recognition tasks and a change detection task, the mental representations of experts and novices are studied in a more direct way than with tasks such as problem sorting or interviews. Results show that the experience and knowledge of physics experts influence the features of visual stimuli that they encode. However, a recognition task designed to probe physics experts' representations of physics problems revealed no evidence for the presence of physics principles. The final study in this dissertation used eye-tracking and a measure of cognitive load to determine that animating multimedia learning content can help to focus learners' attention towards relevant items on the screen and in some cases reduce cognitive load as well.
We develop an Easy Java Simulation (EJS) model for students to experience the physics of idealized one-dimensional collision carts. The physics model is described and simulated by both continuous dynamics and discrete transition during collision. In designing the simulations, we discuss briefly three pedagogical considerations namely (1) a consistent simulation world view with a pen and paper representation, (2) a data table, scientific graphs and symbolic mathematical representations for ease of data collection and multiple representational visualizations and (3) a game for simple concept testing that can further support learning. We also suggest using a physical world setup augmented by simulation by highlighting three advantages of real collision carts equipment such as a tacit 3D experience, random errors in measurement and the conceptual significance of conservation of momentum applied to just before and after collision. General feedback from the students has been relatively positive, and we hope teachers will find the simulation useful in their own classes.
Non-sparse Linear Representations for Visual Tracking with Online Reservoir Metric Learning
Most sparse linear representation-based trackers need to solve a computationally expensive L1-regularized optimization problem. To address this problem, we propose a visual tracker based on non-sparse linear representations, which admit an efficient closed-form solution without sacrificing accuracy. Moreover, in order to capture the correlation information between different feature dimensions, we learn a Mahalanobis distance metric in an online fashion and incorporate the learned metric into the optimization problem for obtaining the linear representation. We show that online metric learning using proximity comparison significantly improves the robustness of the tracking, especially on those sequences exhibiting drastic appearance changes. Furthermore, in order to prevent the unbounded growth in the number of training samples for the metric learning, we design a time-weighted reservoir sampling method to maintain and update limited-sized foreground and background sample buffers for balancing sample diversity ...
Quantifying the implicit process flow abstraction in SBGN-PD diagrams with Bio-PEPA
For a long time biologists have used visual representations of biochemical networks to gain a quick overview of important structural properties. Recently SBGN, the Systems Biology Graphical Notation, has been developed to standardise the way in which such graphical maps are drawn in order to facilitate the exchange of information. Its qualitative Process Diagrams (SBGN-PD) are based on an implicit Process Flow Abstraction (PFA) that can also be used to construct quantitative representations, which can be used for automated analyses of the system. Here we explicitly describe the PFA that underpins SBGN-PD and define attributes for SBGN-PD glyphs that make it possible to capture the quantitative details of a biochemical reaction network. We implemented SBGNtext2BioPEPA, a tool that demonstrates how such quantitative details can be used to automatically generate working Bio-PEPA code from a textual representation of SBGN-PD that we developed. Bio-PEPA is a process algebra that was designed for implementing quant...
On-line monitoring and analysis of reactor vessel integrity
A method is described for on-line monitoring and analysis of nuclear reactor pressure vessel integrity in a unit in which reactor coolant is circulated along the inner wall of the pressure vessel, the method comprising the steps of: generating on an on-line basis, temperature signals representative of the temperature of the reactor coolant circulating along the inner wall of the pressure vessel; generating on an on-line basis, a pressure signal representative of the reactor coolant pressure; generating a signal representative of fast neutron fluence to which the reactor pressure vessel has been subjected; generating as a function of the fluence signal a visual representation of the actual real time reference nil-ductibility transition temperature (RT/sub ndt/) across the entire pressure vessel wall thickness at a preselected critical location in the wall; generating as a function of transients in the reactor coolant temperature and pressur signals, a visual representation of the real time required RT/sub ndt/, across the entire pressure vessel wall thickness at the selected critical location, the required RT/sub ndt/ being the RT/sub ndt/ that would be required in the pressure vessel wall for flaw initiation to occur as a result of stresses set-up by the transients; and superimposing the visual representations of the real-time actual and required RT/sub ndt's/ for flaw initiation across the entire pressure vessel wall thickness for the selected critical location to generate a visual representation of the difference in value between the actual and required RT/sub ndt/ presented as an RT/sub ndt/ margin.
The GR Embedding program displays a representation of the curvature of space near a massive object. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the gr_embedding.jar file will run the program if Java is installed. GR Embedding is part of a suite of Open Source Physics programs that model aspects of General Relativity. Other programs provide additional visualizations. They can be found by searching ComPADRE for Open Source Physics, OSP, or General Relativity.
A common network of functional areas for attention and eye movements
Functional magnetic resonance imaging (fMRI) and surface-based representations of brain activity were used to compare the functional anatomy of two tasks, one involving covert shifts of attention to peripheral visual stimuli, the other involving both attentional and saccadic shifts to the same stimuli. Overlapping regional networks in parietal, frontal, and temporal lobes were active in both tasks. This anatomical overlap is consistent with the hypothesis that attentional and oculomotor processes are tightly integrated at the neural level.
Exercise your visual thinking. [Graphic representation in publishing
Figures and tables are a means of presenting high-density information in a pleasing manner. Editors who exercise their visual thinking can improve dense, uninviting reports by suggesting meaningful illustrations for an author's approval. Illustrations can clarify descriptive passages or even replace them. Editors are urged to sketch what they think is needed. Examples of selecting information for graphic representation are given and the appropriateness of a photograph, illustration, graph, or logic diagram is discussed.
This presentation from green building consultant Dan Saddler provides an introduction to the basics of green building. "Green building" itself is defined, and the sustainability concepts involved are explored. The presentation is mostly visual but also contains some very useful statistics and graphical representations of data. Insulation techniques, sustainable building materials and methods, site protection and location and other related topics are covered. This document may be downloaded in PDF file format.
Graphics and Flow Visualization of Computer Generated Flow Fields
Flow field variables are visualized using color representations described on surfaces that are interpolated from computational grids and transformed to digital images. Techniques for displaying two and three dimensional flow field solutions are addressed. The transformations and the use of an interactive graphics program for CFD flow field solutions, called PLOT3D, which runs on the color graphics IRIS workstation are described. An overview of the IRIS workstation is also described.
Various papers on artificial intelligence in machine vision and robotics are presented. The general topics addressed include: design of a robot head, machine vision inspection techniques, segmentation of fused range and intensity imagery, parallel and VLSI architectures for machine vision, comparison of range image segmentation algorithms, state of the art in postcanny edge detection, simulation and visualization environments for autonomous robots, exploration of recognition by components representation and matching, reactive robotic control strategies, image processing techniques.
A discontinuity-geometry view of the relationship between saddle-node and grazing bifurcations
In this study we will introduce a topological approach termed as discontinuity-geometry for both analysis and visualization of the dynamics of periodically-forced impact oscillators. After a brief outline of the methodology and the general representation of trajectories with impacts the framework will be used to analyse grazing bifurcations. In particular it will be used to geometrically explain why there is sometimes a saddle-node bifurcation present in the vicinity of grazing bifurcations and why it is sometimes absent.
Mining co-distribution patterns for large crime datasets
Crime activities are geospatial phenomena and as such are geospatially, thematically and temporally correlated. We analyze crime datasets in conjunction with socio-economic and socio-demographic factors to discover co-distribution patterns that may contribute to the formulation of crime. We propose a graph based dataset representation that allows us to extract patterns from heterogeneous areal aggregated datasets and visualize the resulting patterns efficiently. We demonstrate our approach with real crime datasets and provide a comparison with other techniques.
A PC based tool for mission plan production
Satellite positioning is managed according to a mission plan (MP) which provides, on a minute accuracy basis, a chronological list of events and associated actions to be performed. This tool, called MM2, is designed under the Windows environment. Excel is used to provide the MP itself. A Visual Basic process then translates it into a graphic symbolic representation called flight plan (FP). During operations, MM2 is also used to log the actual event dates and/or dated OPS Manager live comments.
This visual essay reports on the production of the photographic text Mum's got to sell the house. The project arose from qualitative action research based upon the strategies of collaborative memory work within the family. The analysis of the project presented here posits that the photograph, and indeed the practice of photography, can be positively understood as the site for the production and representation of memory, one which is future oriented and active in the construction of identity and agency.
2D Log-Gabor Wavelet Based Action Recognition
The frequency response of log-Gabor function matches well the frequency response of primate visual neurons. In this letter, motion-salient regions are extracted based on the 2D log-Gabor wavelet transform of the spatio-temporal form of actions. A supervised classification technique is then used to classify the actions. The proposed method is robust to the irregular segmentation of actors. Moreover, the 2D log-Gabor wavelet permits more compact representation of actions than the recent neurobiological models using Gabor wavelet.
This paper explores contemporary Greek political praxis and social imagination through the study of Crete's position in engagements with the -crisis-. The essay employs the visual as an object and a method of analysis and examines a series of social spheres ranging from public protesting to televisual representation. The paper explores the cultural productivity of notions of native resistance in the current context as well as Cretan responses to the use of traditionalist idioms within the -crisis-.
The role of magnetic resonance imaging in tumors of the inner nose and the paranasal sinuses
In the examination of the inner nose and the paranasal sinuses, magnetic resonance imaging impresses by its excellent representation of anatomical structures, due above all to the multiplanar orientation of slices, the good possibility to differentiate soft tissue structures, and the accurate visualization of lymph nodes and vessels without contrast medium. Osseous lesions can be better assessed by computed tomography, however, magnetic resonance imaging can indirectly demonstrate bone destructions, too. (orig.).
Case role filling as a side effect of visual search
This paper addresses the problem of generating communicatively adequate extended responses in the absence of specific knowledge concerning the intentions of the questioner. The authors formulate and justify a heuristic for the selection of optional deep case slots not contained in the question as candidates for the additional information contained in an extended response. It is shown that, in a visually present domain of discourse, case role filling for the construction of an extended response can be regarded as a side effect of the visual search necessary to answer a question containing a locomotion verb. The paper describes the various representation constructions used in the German language dialog system HAM-ANS for dealing with the semantics of locomotion verbs and illustrates their use in generating extended responses. In particular, it outlines the structure of the geometrical scene description, the representation of events in a logic-oriented semantic representation language, the case-frame lexicon and the representation of the referential semantics based on the flavor system. The emphasis is on a detailed presentation of the application of object-oriented programming methods for coping with the semantics of locomotion verbs. The process of generating an extended response is illustrated by an extensively annotated trace. 13 references.
Transformation-invariant visual representations in self-organizing spiking neural networks.
The ventral visual pathway achieves object and face recognition by building transformation-invariant representations from elementary visual features. In previous computer simulation studies with rate-coded neural networks, the development of transformation-invariant representations has been demonstrated using either of two biologically plausible learning mechanisms, Trace learning and Continuous Transformation (CT) learning. However, it has not previously been investigated how transformation-invariant representations may be learned in a more biologically accurate spiking neural network. A key issue is how the synaptic connection strengths in such a spiking network might self-organize through Spike-Time Dependent Plasticity (STDP) where the change in synaptic strength is dependent on the relative times of the spikes emitted by the presynaptic and postsynaptic neurons rather than simply correlated activity driving changes in synaptic efficacy. Here we present simulations with conductance-based integrate-and-fire (IF) neurons using a STDP learning rule to address these gaps in our understanding. It is demonstrated that with the appropriate selection of model parameters and training regime, the spiking network model can utilize either Trace-like or CT-like learning mechanisms to achieve transform-invariant representations. PMID:22848199
A new approach to machine-based perception of monocular images
A new approach to machine-based visual perception of monocular images is presented and demonstrated. The approach employs a recursive procedure to generate a series of ''reconstructed'' versions of the raw video image. The procedure is designed to imitate certain perceptual organization functions of the human visual system. Recognition of object categories is attempted at each step by comparing the newly generated regions to stored object categories. These generated regions may have relatively few edges or region pixels in common with any of the regions in the raw video image. Category retrieval is carried out using a software-based content-addressing scheme which provides access to complete object representations in memory using incomplete portions of the representation. The category representation scheme is sufficiently general to allow a variety of poorly correlated images of specific category examples to be represented and recognized by a single general category representation. These properties are illustrated using a group of distorted, defective and idealized images of ascii A's and handguns. 7 refs., 10 figs.
Forces are experienced in actions on objects. The mechanoreceptor system is stimulated by proximal forces in interactions with objects, and experiences of force occur in a context of information yielded by other sensory modalities, principally vision. These experiences are registered and stored as episodic traces in the brain. These stored representations are involved in generating visual impressions of forces and causality in object motion and interactions. Kinematic information provided by vision is matched to kinematic features of stored representations, and the information about forces and causality in those representations then forms part of the perceptual interpretation. I apply this account to the perception of interactions between objects and to motions of objects that do not have perceived external causes, in which motion tends to be perceptually interpreted as biological or internally caused. I also apply it to internal simulations of events involving mental imagery, such as mental rotation, trajectory extrapolation and judgment, visual memory for the location of moving objects, and the learning of perceptual judgments and motor skills. Simulations support more accurate judgments when they represent the underlying dynamics of the event simulated. Mechanoreception gives us whatever limited ability we have to perceive interactions and object motions in terms of forces and resistances; it supports our practical interventions on objects by enabling us to generate simulations that are guided by inferences about forces and resistances, and it helps us learn novel, visually based judgments about object behavior. PMID:22730922
Forces are experienced in actions on objects. The mechanoreceptor system is stimulated by proximal forces in interactions with objects, and experiences of force occur in a context of information yielded by other sensory modalities, principally vision. These experiences are registered and stored as episodic traces in the brain. These stored representations are involved in generating visual impressions of forces and causality in object motion and interactions. Kinematic information provided by vision is matched to kinematic features of stored representations, and the information about forces and causality in those representations then forms part of the perceptual interpretation. I apply this account to the perception of interactions between objects and to motions of objects that do not have perceived external causes, in which motion tends to be perceptually interpreted as biological or internally caused. I also apply it to internal simulations of events involving mental imagery, such as mental rotation, trajectory extrapolation and judgment, visual memory for the location of moving objects, and the learning of perceptual judgments and motor skills. Simulations support more accurate judgments when they represent the underlying dynamics of the event simulated. Mechanoreception gives us whatever limited ability we have to perceive interactions and object motions in terms of forces and resistances; it supports our practical interventions on objects by enabling us to generate simulations that are guided by inferences about forces and resistances, and it helps us learn novel, visually based judgments about object behavior. (Contains 13 footnotes.)
Involuntary images and visual memories are prominent in many types of psychopathology. Patients with posttraumatic stress disorder, other anxiety disorders, depression, eating disorders, and psychosis frequently report repeated visual intrusions corresponding to a small number of real or imaginary events, usually extremely vivid, detailed, and with highly distressing content. Both memory and imagery appear to rely on common networks involving medial prefrontal regions, posterior regions in the medial and lateral parietal cortices, the lateral temporal cortex, and the medial temporal lobe. Evidence from cognitive psychology and neuroscience implies distinct neural bases to abstract, flexible, contextualized representations (C-reps) and to inflexible, sensory-bound representations (S-reps). We revise our previous dual representation theory of posttraumatic stress disorder to place it within a neural systems model of healthy memory and imagery. The revised model is used to explain how the different types of distressing visual intrusions associated with clinical disorders arise, in terms of the need for correct interaction between the neural systems supporting S-reps and C-reps via visuospatial working memory. Finally, we discuss the treatment implications of the new model and relate it to existing forms of psychological therapy. (Contains 2 tables, 2 figures and 1 footnote.)
Behavior model for performance assessment.
Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result.
With the two dimensional (2D) site and the three dimensional (3D) cube representations in two-photon absorption [M.T. Sun, J.N. Chen, H.X. Xu, J. Chem. Phys. 128(1-6) (2008) 064106], the charge transfer and electron-hole coherence for centrosymmetric and asymmetric fluorene derivatives have been investigated theoretically. For centrosymmetric fluorene derivative, the excitation from the ground state to intermediate excited state by the first photon is a Frenkel excitation; while the excitation by the second photon from the intermediate excited state to the final excited state is an intraband excitation, and charge transfers from one substituent to the other substituent. For asymmetric fluorene derivative in TPA, the excitations by the first and second photons are all charge transfer excited states. Theoretical visual evidence has been provided that diphenylamino-end groups do not strongly participate in pure 2PA, which confirmed the experimental assumption. We also visualize the orientation and strength of transition polarizability density (TPD) in TPA with 3D cube representation. The transition probability in TPA also was visualized with 2D site representation.
There is a growing recognition with the visual analytics community that interaction and inquiry are inextricable. It is through the interactive manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the interaction challenges raised in the original visual analytics research and development agenda and further explores the relationship between interaction and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of interaction, which must include theories and testable premises about the most appropriate mechanisms for human-information interaction. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied interaction; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of interaction is to support the visual analytics community through the recognition and implementation of best practices in the representation of and interaction with visual displays.
This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest and polaroid glasses were used for the examination of stereoscopic vision, while Cover test and Hirschberg's pupils reflex test were used for the evaluation of strabismus. In the area of non-verbal abilities was evaluated visual discrimination, visuomotor integration, constructive praxia, visual memory, strategy formation, non-verbal reasoning and the representational dimension of drawings. Subtests of ACADIA test of developmental abilities were used for the evaluation of non-verbal abilities (Atkinson et al., 1972). Statistically significant relations between strabismus and constructive praxia (p = 0.009), visual memory (p = 0.037), strategy formation (0.040) and the quality of drawings were determined by the results analysis. According to our findings, children with divergent strabismus achieve the best results. Children with stereoscopic vision generally achieve better results in all the examined areas of non-verbal abilities, and statistically significant relations were determined in the areas of visuomotor coordination (0.002), constructive praxia (0.026) and non-verbal reasoning (0.015), which are directly connected to visuospatial abilities. Children with convergent strabismus achieve significantly lower results in the areas of constructive praxia, visual memory, strategy formation and representational dimension of drawings, and children with the lack of stereoscopic vision--in the areas of visuomotor integration, constructive praxia and non-verbal reasoning. (Contains 2 tables.)
This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest and polaroid glasses were used for the examination of stereoscopic vision, while Cover test and Hirschberg's pupils reflex test were used for the evaluation of strabismus. In the area of non-verbal abilities was evaluated visual discrimination, visuomotor integration, constructive praxia, visual memory, strategy formation, non-verbal reasoning and the representational dimension of drawings. Subtests of ACADIA test of developmental abilities were used for the evaluation of non-verbal abilities (Atkinson et al., 1972). Statistically significant relations between strabismus and constructive praxia (p=0.009), visual memory (p=0.037), strategy formation (0.040) and the quality of drawings were determined by the results analysis. According to our findings, children with divergent strabismus achieve the best results. Children with stereoscopic vision generally achieve better results in all the examined areas of non-verbal abilities, and statistically significant relations were determined in the areas of visuomotor coordination (0.002), constructive praxia (0.026) and non-verbal reasoning (0.015), which are directly connected to visuospatial abilities. Children with convergent strabismus achieve significantly lower results in the areas of constructive praxia, visual memory, strategy formation and representational dimension of drawings, and children with the lack of stereoscopic vision--in the areas of visuomotor integration, constructive praxia and non-verbal reasoning. PMID:21536409
Electrophysiological methods were employed to determine whether or not partial visual cortical lesions in neonatal (7--11-day) hamster produced large scotomas in the cortical visual representation. In cases where such scotomas were present electrophoretic deposits of radioactive amino acids in the visually responsive ''cortical remnant'' of the damaged hemisphere resulted in labelling throughout the lower portion of the stratum griseum superficiale and the stratum opticum of the ipsilateral superior colliculus. No differential labeling of the part of the colliculus which was topographically matched with the remaining visual representation in the cortical remnant was observed. In normal hamsters relatively localized, visual cortical deposits of radioactive amino acids resulted in superficial layer labeling only in portions of the colliculus which corresponded to the locus of the cortical deposit. In a similar fashion, small lesions at physiologically defined loci in the cortical remnant produced degeneration throughout most of the superficial tectal laminae, but a more restricted ''focus'' of denser degeneration was also visible in these cases. The position of this focus in the colliculus for a given cortical lesion varied with the nature of the visual map in the cortical remnant. In several additional neonatally brain-damaged hamsters large lesions of the visual cortex in the intact hemisphere were combined with radioactive amino acid deposits in the cortical remnant to determine whether or not axons from the crossed corticocollicular pathway previously demonstrated in such hamsters were intermingled with fibers from the ipsilateral corticotectal projection. In alternate sections processed for autoradiography or by the Fink-Heimer ('67) method autoradiographic label and degeneration argyrophilia were both observed in the medical part of the colliculus ipsilateral to the neonatal cortical lesion.
Abstract in portuguese Três tarefas intervenientes (verbal, visual e aritmética), realizadas durante estudo de uma cena, foram utilizadas com o objetivo de explicitar a natureza da representação memorizada das distâncias entre os objetos da cena. O efeito delas sobre a representação das distâncias foi estimado por expoentes da função potência baseados em julgamentos da distância relembrada entre pares de objetos e reprodução em desenho da disposição espacial dos objetos da cena. (more) Os resultados mostram que expoentes obtidos não diferem da unidade. Por outro lado, os estimados pelas coordenadas x e y com base nos desenhos são menores. Tanto os expoentes obtidos nos julgamentos de magnitude de distância aos pares como aqueles a partir do eixo y do desenho foram afetados pela realização da tarefa aritmética durante o tempo de estudo, mas não pela realização da tarefa visual. Estes resultados sugerem que componentes visuais e espaciais contribuem com pesos diferenciados para a qualidade da representação. Abstract in english Three intervening tasks (verbal, visual and arithmetical) performed by participants during the study of a scene were used to explicit the nature of the memorized representations of the distances between scene objects. The effect of the intervening task on the distances representation was determined through the exponent of the power function estimated from the judgments of distances based on estimation and the distances between objects in scene. The results showed that the (more) exponents obtained by magnitude estimation do not differ from unit. On the contrary, the exponents obtained on the basis of the x and y coordinates of the drawing have lower values. The exponents obtained with judgments of magnitude and from the y axe of the drawing were affected by the arithmetical task performed during the study time, but not by visual one. These results suggest that visual and spatial components contribute with differentiated weights for the representation quality.
Visual Short-term Memory Load Reduces Retinotopic Cortex Response to Contrast.
Load Theory of attention suggests that high perceptual load in a task leads to reduced sensory visual cortex response to task-unrelated stimuli resulting in "load-induced blindness" [e.g., Lavie, N. Attention, distraction and cognitive control under load. Current Directions in Psychological Science, 19, 143-148, 2010; Lavie, N. Distracted and confused?: Selective attention under load. Trends in Cognitive Sciences, 9, 75-82, 2005]. Consideration of the findings that visual STM (VSTM) involves sensory recruitment [e.g., Pasternak, T., & Greenlee, M. Working memory in primate sensory systems. Nature Reviews Neuroscience, 6, 97-107, 2005] within Load Theory led us to a new hypothesis regarding the effects of VSTM load on visual processing. If VSTM load draws on sensory visual capacity, then similar to perceptual load, high VSTM load should also reduce visual cortex response to incoming stimuli leading to a failure to detect them. We tested this hypothesis with fMRI and behavioral measures of visual detection sensitivity. Participants detected the presence of a contrast increment during the maintenance delay in a VSTM task requiring maintenance of color and position. Increased VSTM load (manipulated by increased set size) led to reduced retinotopic visual cortex (V1-V3) responses to contrast as well as reduced detection sensitivity, as we predicted. Additional visual detection experiments established a clear tradeoff between the amount of information maintained in VSTM and detection sensitivity, while ruling out alternative accounts for the effects of VSTM load in terms of differential spatial allocation strategies or task difficulty. These findings extend Load Theory to demonstrate a new form of competitive interactions between early visual cortex processing and visual representations held in memory under load and provide a novel line of support for the sensory recruitment hypothesis of VSTM. PMID:22905823
Being able to access educational or training resources or programmes anytime and anywhere is one of the challenges that e-learning and now m-learning seek to address, with the aim of maintaining the highest possible level of professional skills. Although hardware and software solutions are now firmly established, instructional design issues are still far from resolved. In this respect, the concept of instrumental conflict, which was inspired by activity theory and by the instrumental genesis concept, explains the obstacles to learning in situations where technical systems are involved. When they are combined, disciplinary objects such as certain educational or training content, pedagogical objects like certain scenarios and formalisms for representation, and technical objects such as softw...
Data-Driven Time-Frequency Analysis
In this paper, we introduce a new adaptive data analysis method to study trend and instantaneous frequency of nonlinear and non-stationary data. This method is inspired by the Empirical Mode Decomposition method (EMD) and the recently developed compressed (compressive) sensing theory. The main idea is to look for the sparsest representation of multiscale data within the largest possible dictionary consisting of intrinsic mode functions of the form $\\{a(t) \\cos(\\theta(t))\\}$, where $a \\in V(\\theta)$, $V(\\theta)$ consists of the functions smoother than $\\cos(\\theta(t))$ and $\\theta'\\ge 0$. This problem can be formulated as a nonlinear $L^0$ optimization problem. In order to solve this optimization problem, we propose a nonlinear matching pursuit method by generalizing the classical matching pursuit for the $L^0$ optimization problem. One important advantage of this nonlinear matching pursuit method is it can be implemented very efficiently and is very stable to noise. Further, we provide a convergence analysis ...
Simulation of Spread and Control of Lesions in Brain
A simulation model for the spread and control of lesions in the brain is constructed using a planar network (graph) representation for the Central Nervous System (CNS). The model is inspired by the lesion structures observed in the case of Multiple Sclerosis (MS), a chronic disease of the CNS. The initial lesion site is at the center of a unit square and spreads outwards based on the success rate in damaging edges (axons) of the network. The damaged edges send out alarm signals which, at appropriate intensity levels, generate programmed cell death. Depending on the extent and timing of the programmed cell death, the lesion may get controlled or aggravated akin to the control of wild fires by burning of peripheral vegetation. The parameter phase space of the model shows smooth transition from uncontrolled situation to controlled situation. The simulations show that the model is capable of generating a wide variety of lesion growth and arrest scenarios.
Archetypal analysis for machine learning and data mining
Archetypal analysis (aa) proposed by Cutler and Breiman (1994) [7] estimates the principal convex hull (pch) of a data set. As such aa favors features that constitute representative ‘corners’ of the data, i.e., distinct aspects or archetypes. We currently show that aa enjoys the interpretability of clustering – without being limited to hard assignment and the uniqueness of svd – without being limited to orthogonal representations. In order to do large scale aa, we derive an efficient algorithm based on projected gradient as well as an initialization procedure we denote FurthestSum that is inspired by the FurthestFirst approach widely used for k-means (Hochbaum and Shmoys, 1985 [14]). We generalize the aa procedure to kernel-aa in order to extract the princip...
Imagine a "machine" where there is no pre-commitment to any particular representational scheme: the desired behaviour is distributed and roughly specified simultaneously among many parts, but there is minimal specification of the mechanism required to generate that behaviour, i.e. the global behaviour evolves from the many relations of multiple simple behaviours. A machine that lives to and from/with Synergy. An artificial super-organism that avoids specific constraints and emerges within multiple low-level implicit bio-inspired mechanisms. KEYWORDS: Complex Science, ArtSBots Project, Swarm Intelligence, Stigmergy, UnManned Art, Symbiotic Art, Swarm Paintings, Robot Paintings, Non-Human Art, Painting Emergence and Cooperation, Art and Complexity, ArtBots: The Robot Talent Show.
Semantic image classification using statistical local spatial relations model
In this paper, a statistical model called statistical local spatial relations (SLSR) is presented as a novel technique of a learning model with spatial and statistical information for semantic image classification. The model is inspired by probabilistic Latent Semantic Analysis (PLSA) for text mining. In text analysis, PLSA is used to discover topics in a corpus using the bag-of-word document representation. In SLSR, we treat image categories as topics, therefore an image containing instances of multiple categories can be modeled as a mixture of topics. More significantly, SLSR introduces spatial relation information as a factor which is not present in PLSA. SLSR has rotation, scale, translation and affine invariant properties and can solve partial occlusion problems. Using the Dirichlet p...
Modeling Reading Vocabulary Learning in Deaf Children in Bilingual Education Programs
The acquisition of reading vocabulary is one of the major challenges for deaf children in bilingual education programs. Deaf children have to acquire a written lexicon that can effectively be used in reading. In this paper, we present a developmental model that describes reading vocabulary acquisition of deaf children in bilingual education programs. The model is inspired by Jiang's model of vocabulary development in a second language (N. Jiang, 2000, 2004a) and the hierarchical model of lexical representation and processing in bilinguals (J. F. Kroll & E. Stewart, 1988). We argue that lexical development in the written language often fossilizes and that many words deaf readers acquire will not reach the final stage of lexical development. We argue that this feature is consistent with many...
Modeling reading vocabulary learning in deaf children in bilingual education programs.
The acquisition of reading vocabulary is one of the major challenges for deaf children in bilingual education programs. Deaf children have to acquire a written lexicon that can effectively be used in reading. In this paper, we present a developmental model that describes reading vocabulary acquisition of deaf children in bilingual education programs. The model is inspired by Jiang's model of vocabulary development in a second language (N. Jiang, 2000, 2004a) and the hierarchical model of lexical representation and processing in bilinguals (J. F. Kroll & E. Stewart, 1988). We argue that lexical development in the written language often fossilizes and that many words deaf readers acquire will not reach the final stage of lexical development. We argue that this feature is consistent with many findings reported in the literature. Finally, we discuss the pedagogical implications of the model. PMID:18048369
Bio-inspired adaptive feedback error learning architecture for motor control
This study proposes an adaptive control architecture based on an accurate regression method called Locally Weighted Projection Regression (LWPR) and on a bio-inspired module, such as a cerebellar-like engine. This hybrid architecture takes full advantage of the machine learning module (LWPR kernel) to abstract an optimized representation of the sensorimotor space while the cerebellar component integrates this to generate corrective terms in the framework of a control task. Furthermore, we illustrate how the use of a simple adaptive error feedback term allows to use the proposed architecture even in the absence of an accurate analytic reference model. The presented approach achieves an accurate control with low gain corrective terms (for compliant control schemes). We evaluate the contribut...
Mirror-Curves and Knot Mosaics
Inspired by the paper on quantum knots and knot mosaics [20] and grid diagrams (or arc presentations) used extensively in the computations of Heegaard-Floer knot homologies [3,6,21] we constructed the equivalent geometrical, but more concise representation of knot mosaics and grid diagrams by using mirror-curves. For mirror-curves treated as knot or link diagrams placed in rectangular square grid RG[p,q] of dimensions p, q we introduced the coding suitable for computers. We proved that the knot mosaic approach [20], mirror-curve approach, and grid diagram approach [3,6,19,21], are equivalent to the tame knot theory. All knots and links that can be obtained from RG[p,2] (p<5) and RG[3,3] we represented by their minimal mirror-curve codes. From mirror-curves we directly computed Kauffman bracket polynomial and L-polynomial [16,17,18].
A 'Neural Sampling Theory (NST)' of learning and memory mechanisms.
The purpose of the Neural Sampling Theory (NST) is to propose a plausible neurobiological explanation for some general properties of learning and memory (LM) phenomena, based on the parallelism and redundancy of the nervous system organization; on the psychological side, the NST is inspired by the Stimulus Sampling and Encoding Variability theories. The sampling process which is its core, is not purely random; it depends on temporal and intensity factors. The NST may be implemented at different levels of the nervous system: synapse, neuron, assembly of neurons. Moreover, it may be incorporated in other formal models and improve their degree of neural realism. For instance it allows to give a more realistic representation of the connection weight in the connectionist models and of the noisy character of the nervous system. PMID:9460562
q-deformed harmonic and Clifford analysis and the q-Hermite and Laguerre polynomials
We define a q-deformation of the Dirac operator, inspired by the one-dimensional q-derivative. This implies a q-deformation of the partial derivatives. By taking the square of this Dirac operator we find a q-deformation of the Laplace operator. This allows us to construct q-deformed Schrödinger equations in higher dimensions. The equivalence of these Schrödinger equations with those defined on q-Euclidean space in quantum variables is shown. We also define the m-dimensional q-Clifford-Hermite polynomials and show their connection with the q-Laguerre polynomials. These polynomials are orthogonal with respect to an m-dimensional q-integration, which is related to integration on q-Euclidean space. The q-Laguerre polynomials are the eigenvectors of an suq(1|1)-representation.
Handling uncertainties in SVM classification
This paper addresses the pattern classification problem arising when available target data include some uncertainty information. Target data considered here is either qualitative (a class label) or quantitative (an estimation of the posterior probability). Our main contribution is a SVM inspired formulation of this problem allowing to take into account class label through a hinge loss as well as probability estimates using epsilon-insensitive cost function together with a minimum norm (maximum margin) objective. This formulation shows a dual form leading to a quadratic problem and allows the use of a representer theorem and associated kernel. The solution provided can be used for both decision and posterior probability estimation. Based on empirical evidence our method outperforms regular SVM in terms of probability predictions and classification performances.
The Application of Architecture Frameworks to Modelling Exploration Operations Costs
Developments in architectural frameworks and system-of-systems thinking have provided useful constructs for systems engineering. DoDAF concepts, language, and formalisms, in particular, provide a natural way of conceptualizing an operations cost model applicable to NASA's space exploration vision. Not all DoDAF products have meaning or apply to a DoDAF inspired operations cost model, but this paper describes how such DoDAF concepts as nodes, systems, and operational activities relate to the development of a model to estimate exploration operations costs. The paper discusses the specific implementation to the Mission Operations Directorate (MOD) operational functions/activities currently being developed and presents an overview of how this powerful representation can apply to robotic space missions as well.
Evolving localizations in reaction-diffusion cellular automata
We consider hexagonal cellular automata with immediate cell neighbourhood and three cell-states. Every cell calculates its next state depending on the integral representation of states in its neighbourhood, i.e. how many neighbours are in each one state. We employ evolutionary algorithms to breed local transition functions that support mobile localizations (gliders), and characterize sets of the functions selected in terms of quasi-chemical systems. Analysis of the set of functions evolved allows to speculate that mobile localizations are likely to emerge in the quasi-chemical systems with limited diffusion of one reagent, a small number of molecules is required for amplification of travelling localizations, and reactions leading to stationary localizations involve relatively equal amount of quasi-chemical species. Techniques developed can be applied in cascading signals in nature-inspired spatially extended computing devices, and phenomenological studies and classification of non-linear discrete systems.
Breaking Bread with the Brethren: Fraternalism and Text in a Black Atlantic Church Community
This ethnographic article examines the constitution of brotherhood at Dixon Bible Chapel (DBC)?a West Indian and African American Brethren church community located in Lithonia, Georgia, a suburb of the Atlanta metropolitan area. Based on my analysis of interview, oral history, and church historical texts collected during fieldwork from 2006 to 2008, I propose that DBC members conceptualize brotherhood as an egalitarian, closely knit form of religious belonging inspired by New Testament representations of the church. Furthermore, I argue that is through DBC brothers? textual rituals that brotherhood is substantiated as a framework for male democratic religious participation and leadership. Though hierarchies of class, ethnicity, gender, and generation segment the ranks of DBC brotherhood an...
Masculinities and the Aesthetics of Love: Reading Terrorism in De Niro's Game and Paradise Now
This article examines Rawi Hage's (2006) De Niro's Game and Hany Abu-Assad's (2005) Paradise Now for their capacity to give us insight into the meanings of racialized masculinities. Neither text represents a very consoling picture of men in war and conflict, but they have a great deal to teach us about the fragility that underpins masculinity in volatile political contexts. Indeed, they give us insight into the affective realities of racial traumas that inhabit our constructions of identity, ideological positionalities, and cultural representation. Inspired by Frantz Fanon's (1952) plea for a new humanism and Paul Gilroy's (2005) assertion that we attend to and politicize human suffering, I propose a psychoanalytic aesthetics of loss as a model for understanding and renewing cultural and p...
QCD inspired relativistic bound state model and meson structures
A QCD inspired relativistic effective Hamiltonian model for the bound states of mesons has been constructed, which integrates the advantages of several QCD effective Hamiltonian models. Based on light-front QCD effective Hamiltonian model, the squared invariant mass operator of meson is used as the effective Hamiltonian. The model has been improved significantly in four aspects: i)it is proved that in center of mass frame and in internal coordinate Hilbert subspace, the total angular momentum of meson is conserved and the mass eigen equation can be expressed in total angular momentum representation and in terms of a set of coupled radial eigen equations for each J; ii)Based on lattice QCD results, a relativistic confining potential is introduced into the effective interaction and the excited states of mesons can be well described; iii)a su(3) flavor mixing interaction is introduced phenomenologically to describe the flavor mixing mesons and the mass eigen equations contain the coupling among different flavor ...
QCD inspired relativistic effective Hamiltonian model for mesons
A QCD inspired relativistic effective Hamiltonian model for mesons has been proposed based on light-front QCD effective Hamiltonian. The squared invariant rest mass operator is used as the effective Hamiltonian. The model has been improved significantly in four major aspects: i) it is proved that in constituent rest frame and in internal Hilbert subspace, the total angular momentum of mesons is conserved, the mass eigen equation can be expressed in total angular momentum representation and in terms of a set of coupled radial eigen equations; ii) a relativistic confining potential is introduced to describe the excited states; iii) an SU(3) flavor mixing interaction is included and a set of coupled mass eigen equations are obtained for different flavor components; iv) the Formula Not Shown c...
The Automatic Evolution of Distributed Controllers to Configure Sensor Network Operation
Tuning the parameters that control the operation of a wireless sensor network, such as sampling rate, is not a simple task. This is partly due to the distributed nature of the problem, but is also a result of the time-varying dynamics that a network experiences. Inspired by the way in which cells alter their behaviour in response to diffused protein concentrations, an abstract representation, termed a discrete gene regulatory network (dGRN), is introduced. Each node runs an identical dGRN controller which controls node activity and interaction. The controllers are authored automatically using an evolutionary algorithm. The communication that occurs between nodes is neither specified nor designed, but emerges naturally. As a particular example, we illustrate that our approach can generate e...
Working memory has been an important concept for psychological science for over 30 years, taking its modern form and inspiration from the work of Baddeley and Hitch (1974). Whilst our collective understanding of the term has evolved and diversified, we show that working memory still remains highly relevant to issues in cognition; contemporary research indicates how both theoretical models and the concept of working memory has much to offer the research discipline. We introduce five empirical studies for this special issue on working memory and show how each paper contributes to the broader understanding of cognition. More specifically these papers constrain ongoing debates about the domain-specific nature of short-term and working memory, the binding of different types of representations, the nature of executive control, and the role of working memory in action control. We attempt to place these four research themes under a larger research framework into which the five experimental articles are located.
Models of Earning and Caring: Determinants of the Division of Work
Les auteurs examinent les determinants possibles des modeles de la repartition des revenus et des activites de soins chez les couples canadiens. En utilisant l'Enquete sociale generale-L'emploi du temps (ESG), ils enumerent cinq modeles de division du travail: complementaire-traditionnel, complementaire-genre inverse, double tache de la femme, double tache de l'homme et roles partages. Tandis que le modele complementaire-traditionnel est en declin, il se retrouve encore chez le tiers des couples. La double tache de la femme constitue la deuxieme categorie en importance, c'est-a-dire qu'on la constate chez 27% des couples en 2005, alors que la double tache de l'homme represente 11%. Les roles partages conviennent a environ un quart des couples. S'inspirant de ces typologies des revenus et d...
4d {N}=2 gauge theories and quivers: the non-simply laced case
We construct the BPS quivers with superpotential for the 4d {N}=2 gauge theories with non-simply laced Lie groups ( B n , C n , F 4 and G 2). The construction is inspired by the BIKMSV geometric engineering of these gauge groups as non-split singular elliptic fibrations. From the categorical viewpoint of arXiv:1203.6734 http://arxiv.org/abs/1203.6734" TargetType="URL"/> , the fibration of the light category L( {g} ) over the (degenerate) Gaiotto curve has a monodromy given by the action of the outer automorphism of the corresponding unfolded Lie algebra. In view of the Katz-Vafa `matter from geometry' mechanism, the monodromic idea may be extended to the construction of ( Q, W) for SYM coupled to higher matter representations. This is done through a construction we call specialization.
Unitary invariants for Hilbert modules of finite rank
A refined notion of curvature for a linear system of Hermitian vector spaces, in the sense of Grothendieck, leads to the unitary classification of a large class of analytic Hilbert modules. Specifically, we study Hilbert sub-modules, for which the localizations are of finite (but not constant) dimension, of an analytic function space with a reproducing kernel. The correspondence between analytic Hilbert modules of constant rank and holomorphic Hermitian bundles on domains of $\\mathbb C^n$ due to Cowen and Douglas, as well as a natural analytic localization technique derived from the Hochschild cohomology of topological algebras play a major role in the proofs. A series of concrete computations, inspired by representation theory of linear groups, illustrate the abstract concepts of the paper.
Bioinspired sparse spectro-temporal representation of speech for robust classification
In this work, a first approach to a robust phoneme recognition task by means of a biologically inspired feature extraction method is presented. The proposed technique provides an approximation to the speech signal representation at the auditory cortical level. It is based on an optimal dictionary of atoms, estimated from auditory spectrograms, and the Matching Pursuit algorithm to approximate the cortical activations. This provides a sparse coding with intrinsic noise robustness, which can be therefore exploited when using the system in adverse environments. The recognition task consisted in the classification of a set of 5 easily confused English phonemes, in both clean and noisy conditions. Multilayer perceptrons were trained as classifiers and the performance was compared to other class...
Semi-supervised action recognition in video via Labeled Kernel Sparse Coding and sparse L1 graph
Recognizing human actions in a video sequence using small number of labeled data are very desirable in practical applications. In this paper an action recognition approach via Labeled Kernel Sparse Coding (LKSC) and sparse L1 graph is proposed under the framework of semi-supervised learning framework. Inspired by the fact that kernel trick can capture the nonlinear similarity of features, we extend the sparse representation classifier (SRC) is extended to the empirical kernel projection space. By using the calculated sparse coding coefficients of both labeled and unlabeled samples as the graph weights, a sparse L1 graph is established in a parameter-free manner. Some experiments are taken on Weizmann human action datasets and a movie sequence of a ballet dance, to investigate the performan...
Simulation of spread and control of lesions in brain.
A simulation model for the spread and control of lesions in the brain is constructed using a planar network (graph) representation for the central nervous system (CNS). The model is inspired by the lesion structures observed in the case of multiple sclerosis (MS), a chronic disease of the CNS. The initial lesion site is at the center of a unit square and spreads outwards based on the success rate in damaging edges (axons) of the network. The damaged edges send out alarm signals which, at appropriate intensity levels, generate programmed cell death. Depending on the extent and timing of the programmed cell death, the lesion may get controlled or aggravated akin to the control of wild fires by burning of peripheral vegetation. The parameter phase space of the model shows smooth transition from uncontrolled situation to controlled situation. The simulations show that the model is capable of generating a wide variety of lesion growth and arrest scenarios. PMID:22319549
Analytical investigation of self-organized criticality in neural networks.
Dynamical criticality has been shown to enhance information processing in dynamical systems, and there is evidence for self-organized criticality in neural networks. A plausible mechanism for such self-organization is activity-dependent synaptic plasticity. Here, we model neurons as discrete-state nodes on an adaptive network following stochastic dynamics. At a threshold connectivity, this system undergoes a dynamical phase transition at which persistent activity sets in. In a low-dimensional representation of the macroscopic dynamics, this corresponds to a transcritical bifurcation. We show analytically that adding activity-dependent rewiring rules, inspired by homeostatic plasticity, leads to the emergence of an attractive steady state at criticality and present numerical evidence for the system's evolution to such a state. PMID:22977096
Mirror-curves and knot mosaics
Inspired by the paper on quantum knots and knot mosaics (Lomonaco and Kauffman, 2008 [18]) and grid diagrams (or arc presentations), used extensively in the computations of Heegaard-Floer knot homology (Bar-Natan, 0000 [16], Cromwell, 1995 [21], Manolescu et al., 2007 [22]), we construct the more concise representation of knot mosaics and grid diagrams via mirror-curves. Tame knot theory is equivalent to knot mosaics (Lomonaco and Kauffman, 2008 [18]), mirror-curves, and grid diagrams (Bar-Natan, 0000 [16], Cromwell, 1995 [21], Kuriya, 2008 [20], Manolescu et al., 2007 [22]). Hence, we introduce codes for mirror-curves treated as knot or link diagrams placed in rectangular square grids, suitable for software implementation. We provide tables of minimal mirror-curve codes for knots and link...
Texture classification from random features.
Inspired by theories of sparse representation and compressed sensing, this paper presents a simple, novel, yet very powerful approach for texture classification based on random projection, suitable for large texture database applications. At the feature extraction stage, a small set of random features is extracted from local image patches. The random features are embedded into a bag-of-words model to perform texture classification; thus, learning and classification are carried out in a compressed domain. The proposed unconventional random feature extraction is simple, yet by leveraging the sparse nature of texture images, our approach outperforms traditional feature extraction methods which involve careful design and complex steps. We have conducted extensive experiments on each of the CUReT, the Brodatz, and the MSRC databases, comparing the proposed approach to four state-of-the-art texture classification methods: Patch, Patch-MRF, MR8, and LBP. We show that our approach leads to significant improvements in classification accuracy and reductions in feature dimensionality. PMID:21768653
Discriminative Local Sparse Representations for Robust Face Recognition
A key recent advance in face recognition models a test face image as a sparse linear combination of a set of training face images. The resulting sparse representations have been shown to possess robustness against a variety of distortions like random pixel corruption, occlusion and disguise. This approach however makes the restrictive (in many scenarios) assumption that test faces must be perfectly aligned (or registered) to the training data prior to classification. In this paper, we propose a simple yet robust local block-based sparsity model, using adaptively-constructed dictionaries from local features in the training data, to overcome this misalignment problem. Our approach is inspired by human perception: we analyze a series of local discriminative features and combine them to arrive at the final classification decision. We propose a probabilistic graphical model framework to explicitly mine the conditional dependencies between these distinct sparse local features. In particular, we learn discriminative...
Automatic Face Recognition System Based on Local Fourier-Bessel Features
We present an automatic face verification system inspired by known properties of biological systems. In the proposed algorithm the whole image is converted from the spatial to polar frequency domain by a Fourier-Bessel Transform (FBT). Using the whole image is compared to the case where only face image regions (local analysis) are considered. The resulting representations are embedded in a dissimilarity space, where each image is represented by its distance to all the other images, and a Pseudo-Fisher discriminator is built. Verification test results on the FERET database showed that the local-based algorithm outperforms the global-FBT version. The local-FBT algorithm performed as state-of-the-art methods under different testing conditions, indicating that the proposed system is highly robust for expression, age, and illumination variations. We also evaluated the performance of the proposed system under strong occlusion conditions and found that it is highly robust for up to 50% of face occlusion. Finally, we...
OpenPsi: A novel computational affective model and its application in video games
This paper introduces OpenPsi, a computational model for emotion generation and function by formalizing part of Dorner's PSI theory, which is an extensive psychological model of human brains, including knowledge representation, perception and bounded rationality. We also borrowed some technical ideas from MicroPsi, one of the concrete implementations of PSI theory by Joscha Bach. The proposed emotional model is then applied to control a virtual robot living in a game world inspired by Minecraft. Simulation experiments have been performed and evaluated for three different scenarios. The emergent emotions fit quite well with these circumstances. The dynamics of this affective model are also analyzed using Lewis's dynamic theory of emotions. Evidences of phase transitions suggested by Lewis a...
From calorimetry to medical imaging: a shining example of successful transfer!
A team at CERN has drawn inspiration from calorimetry methods developed for high-energy physics to create a new positron-emission tomography system for use in medical imaging, which they’ve dubbed AX-PET. With support from European and American laboratories*, the project is reaching fruition, as initial tests confirm its promise. Snapshot of a “phantom”, a test object, surrounded by the AX-PET photon detectors. Positron-emission tomography (PET) is a medical imaging technique based on the matter-antimatter interaction that can provide a three-dimensional representation of the metabolic activity of an organ. To do so, radioactive marker molecules are first injected into the subject. As the marker decays, it emits positrons (antimatter particles), which are annihilated upon encountering electrons in the surrounding environment. The resulting flash, consisting of two photons, is detected by the PET machine. In conventional PET systems, it is impossible to improv...
CHICANA/O STUDENT JOURNALISTS MAP OUT A CHICANA/O JOURNALISM PRACTICE
Research documenting the media under-representation of people of color indicates that unless journalists re-imagine the way they report on communities of color, those growing segments may be left without a stake in the “public imaginary.” In this paper, I suggest that journalism educators turn their attention to Chicano/a student journalists in order to begin the process of re-envisioning newsgathering and writing in ways that more accurately depict and inform Latino/a communities. Driven by a collaboration between myself and undergraduate student producers of Venceremos, a bilingual Chicano/a student publication at a western state university, this paper builds a case for why these student journalists are an important source of knowledge and inspiration for journalism educato...
Archetypal Analysis for Machine Learning
Archetypal analysis (AA) proposed by Cutler and Breiman in [1] estimates the principal convex hull of a data set. As such AA favors features that constitute representative ’corners’ of the data, i.e. distinct aspects or archetypes. We will show that AA enjoys the interpretability of clustering - without being limited to hard assignment and the uniqueness of SVD - without being limited to orthogonal representations. In order to do large scale AA, we derive an efficient algorithm based on projected gradient as well as an initialization procedure inspired by the FURTHESTFIRST approach widely used for K-means [2]. We demonstrate that the AA model is relevant for feature extraction and dimensional reduction for a large variety of machine learning problems taken from computer vision, neuroimaging, text mining and collaborative filtering.
Mathematical aspects of quantum field theory
Over the last century quantum field theory has made a significant impact on the formulation and solution of mathematical problems and inspired powerful advances in pure mathematics. However, most accounts are written by physicists, and mathematicians struggle to find clear definitions and statements of the concepts involved. This graduate-level introduction presents the basic ideas and tools from quantum field theory to a mathematical audience. Topics include classical and quantum mechanics, classical field theory, quantization of classical fields, perturbative quantum field theory, renormalization, and the standard model. The material is also accessible to physicists seeking a better understanding of the mathematical background, providing the necessary tools from differential geometry on such topics as connections and gauge fields, vector and spinor bundles, symmetries and group representations.
Shaking the Tree, Making a Rhizome: Towards a Nomadic Geophilosophy of Science Education
This essay enacts a philosophy of science education inspired by Gilles Deleuze and Felix Guattari's figurations of rhizomatic and nomadic thought. It imagines rhizomes shaking the tree of modern Western science and science education by destabilising arborescent conceptions of knowledge as hierarchically articulated branches of a central stem or trunk rooted in firm foundations, and explores how becoming nomadic might liberate science educators from the sedentary judgmental positions that serve as the nodal points of Western academic science education theorising. This is demonstrated by commencing two rhizomatic textual assemblages that generate questions, provocations and challenges to dominant discourses and assumptions of contemporary science education. The first of these addresses cultural representations of Sir Isaac Newton and the second makes multiple, hybrid connections among the parasites, mosquitoes, humans, technologies and socio-technical relations signified by malaria.
From the Big Bang to the Multiverse: Translations in Space and Time
Since 2004, I have been collaborating with artist Josiah McElheny on the design of cosmological sculptures, inspired originally by the chandeliers of the Metropolitan Opera House in New York. This article describes the science behind the four works that have emerged from this collaboration to date: An End to Modernity (2005), The Last Scattering Surface (2006), The End of the Dark Ages (2008), and Island Universe (2008). These works incorporate idealized representations of many fundamental aspects of contemporary cosmology, including expansion of the universe, the last scattering surface, cosmic microwave background anisotropies, the growth and morphological transformation of galaxies, the rise and fall of the quasar population, the development of large scale structure, and the possibility that our universe is one of many cosmic islands in an eternally inflating multiverse. A companion article describes the history of the collaboration.
The Gestalt heuristic: emerging abstraction to improve combinatorial search
Nowadays, many engineering applications require the minimization of a cost function such as decreasing the delivery time or the used space, reducing the development effort, and so on. Not surprisingly, research in optimization is one of the most active fields of computer science. Metaheuristics are part of the state-of-the-art techniques for combinatorial optimization. But their success comes at the price of considerable efforts in design and development time. Can we go further and automate their preparation? Especially when time is limited, dedicated techniques are unknown or the tackled problem is not well understood? The Gestalt heuristic, a search based on meta-modeling, answers those questions. Our approach, inspired by Gestalt psychology, considers the problem representation as a key...
Fundamental length in quantum theories with PT-symmetric Hamiltonians II: The case of quantum graphs
Manifestly non-Hermitian quantum graphs with real spectra are introduced and shown tractable as a new class of phenomenological models with several appealing descriptive properties. For illustrative purposes, just equilateral star-graphs are considered here in detail, with non-Hermiticities introduced by interactions attached to the vertices. The facilitated feasibility of the analysis of their spectra is achieved via their systematic approximative Runge-Kutta-inspired reduction to star-shaped discrete lattices. The resulting bound-state spectra are found real in a discretization-independent interval of couplings. This conclusion is reinterpreted as the existence of a hidden Hermiticity of our models, i.e., as the standard and manifest Hermiticity of the underlying Hamiltonian in one of less usual, {\\em ad hoc} representations ${\\cal H}_j$ of the Hilbert space of states in which the inner product is local (at $j=0$) or increasingly nonlocal (at $j=1,2, ...$). Explicit examples of these (of course, Hamiltonian...
ABSTRACT This paper proposes a dynamic theory of embodiment that aims to get beyond the absent moving body in embodied social theory. The first somatic revolution, inspired by Merleau Ponty, provided theories based on the feeling and experience of the body. The theory of dynamic embodiment focuses instead on the doing itself as embodied social action, in which the embodied person is fore-grounded as a complex resource for meaning making. This represents a theoretical enrichment of the earlier turn to the body in social theory, which tended to separate the semiotic, as necessarily representational and/or linguistic, from the somatic as a wide range of corporeal processes and practices assumed to be separated from mind, language and/or conscious thought. We argue that overcoming this persist...
Stable Takens' Embeddings for Linear Dynamical Systems
Takens' Embedding Theorem remarkably established that concatenating M previous outputs of a dynamical system into a vector (called a delay coordinate map) can be a one-to-one mapping of a low-dimensional attractor from the system state-space. However, Takens' theorem is fragile because even small imperfections can induce arbitrarily large errors in the attractor representation. We extend Takens' result to establish explicit, non-asymptotic sufficient conditions for a delay coordinate map to form a stable embedding in the restricted case of linear dynamical systems and observation functions. Our work is inspired by the field of Compressive Sensing (CS), where results guarantee that low-dimensional signal families can be robustly reconstructed if they are stably embedded by a measurement operator. However, in contrast to typical CS results, i) our sufficient conditions are independent of the size of the ambient state space (N), and ii) some system and measurement pairs have fundamental limits on the conditionin...
Simplifying the growth of hybrid single-crystals by using nanoparticle precursors: the case of AgI
We report the synthesis of a series of AAgmIn single-crystals within 24 h, at room temperature, utilizing AgI nanoparticles (NPs) as the precursor. The AgI NPs impart high reactivity under mild conditions and favor the growth kinetics. 0D, 1D and 2D iodoargentate crystals can be obtained. This work represents the first application of NPs in the field of organo-metal-halide crystals and will inspire the design of other AMmXn crystals.We report the synthesis of a series of AAgmIn single-crystals within 24 h, at room temperature, utilizing AgI nanoparticles (NPs) as the precursor. The AgI NPs impart high reactivity under mild conditions and favor the growth kinetics. 0D, 1D and 2D iodoargentate crystals can be obtained. This work represents the first application of NPs in the field of organo-metal-halide crystals and will inspire the design of other AMmXn crystals. Electronic supplementary information (ESI) available: XPS spectra of AgI NPs, schematic representation of the formation process of [Ag4I8]4- in 2, UV-Vis spectra of the DTMA-Ag-I clusters, analysis of force balance of a crystal at the interface between H2O and CH2Cl2 and crystal structure depiction of 1-4. CIF files of 1-4 are also provided. CCDC reference numbers 863848, 863849, 863850 and 863851. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2nr30139c
Art and Social Justice Education: Culture as Commons
"Art and Social Justice Education" offers inspiration and tools for educators to craft critical, meaningful, and transformative arts education curriculum and arts integration projects. The images, descriptive texts, essays, and resources are grounded within a clear social justice framework and linked to ideas about culture as commons. Essays and a section written by and for teachers who have already incorporated contemporary artists and ideas into their curriculums help readers to imagine ways to use the content in their own settings. This book is enhanced by a Companion Website (www.routledge.com/cw/quinn) featuring artists and artworks, project examples, and dialogue threads for educators. Proposing that art can contribute in a wide range of ways to the work of envisioning and making a more just world, this imaginative, practical, and engaging sourcebook of contemporary artists' works and education resources advances the field of arts education, locally, nationally, and internationally, by moving beyond models of discipline-based or expressive art education. It will be welcomed by all educators seeking to include the arts and social justice in their curricula. Part I, The Commons: Redistribution of Resources and Power, begins with an introduction to section one by Therese Quinn and contains the following: (1) Justseeds: An Artists' Cooperative (David Darts); (2) Heidi Cody: Letters to the World and the ABCs of Visual Culture (Kevin Tavin); (3) Kutiman: It's the Mother of All Funk Chords (K. Wayne Yang); (4) ToroLab: Border Research Gone Molecular (Nato Thompson); (5) Mequitta Ahuja: Afro-Galaxy (Romi Crawford); (6) Emily Jacir: The Intersection of Art and Politics (Edie Pistolesi); (7) Paula Nicho Cumez: Crossing Borders (Kryssi Staikidis); (8) Rafael Trelles: Cleaning Up the Stain of Militarism (Nicolas Lampert); (9) Experience, Discover, Interpret, and Communicate: Material Culture Studies and Social Justice in Art Education (Doug Bandy); (10) Educational Crisis: An Artistic Intervention (Dipti Desai and Elizabeth Koch); and (11) Social Media/Social Justice: The (Creative) Commons and K-12 Art Education (Robert W. Sweeny and Hannah Johnston). Part II, Our Cultures: Recognition and Representation, begins with an introduction to section two by John Ploof and contains the following: (12) Kaisa Leka: Confusing the Disability/Ability Divide (Carrie Sandahl); (13) Darrel Morris: Men Don't Sew in Public (Donal O'Donoghue); (14) Nicholas Galanin: Imaginary Indian and the Indigenous Gaze (Anne-Marie Tupuola); (15) Kimsooja: The Performance of Universality (Dalida Maria Benfield); (16) Xu Bing: Words of Art (Buzz Spector); (17) Bernard Williams: Art as Reinterpretation, Identity as Art (James Haywood Rolling, Jr.); (18) Hock E Aye Vi Edgar Heap of Birds: Beyond the Chief (Elizabeth Delacruz); (19) Samuel Fosso: Queering Performances of Realness (G. E. Washington); (20) Cultural Conversations in Spiral Curriculum (Olivia Gude); (21) Arts Making as an Act of Theory (Miia Collanus and Tiina Heinonen); and (22) Pedagogy, Collaboration, and Transformation: A Conversation with Brett Cook (Korina Jocson and Brett Cook). Part III, Toward Futures: Social and Personal Transformation, begins with an introduction to section three by Lisa Hochtritt and contains the following: (23) Harrell Fletcher: Shaping a New Social (Juan Carlos Castro); (24) Pinky & Bunny: Critical Pedagogy 2.0 (Steven Ciampaglia); (25) La Pocha Nostra: Practicing Mere Life (Jorge Lucero); (26) Future Farmers: Leaping Over the Impossible Present (A. Laurie Palmer); (27) Appalshop: Learning from Rural Youth Media (Maritza Bautista); (28) Navjot Altaf: What Public, Whose Art? (Manisha Sharma); (29) The Chiapas Photography Project: You Can't Unsee It (Lisa Yun Lee); (30) Dilomprizulike: Art as Political Agency (Raimundo Martins); (31) In Search of Clean Water and Critical Environmental Justice: Collaborative Artistic Responses Through the Possibilities of Sustainability and Appropriate Technologies (B. Stephen Carpenter, II and Marissa Munoz); (32) Opening Spaces for Subj
A Knowledge-Based Representation Scheme for Environmental Science Models
One of the primary methods available for studying environmental phenomena is the construction and analysis of computational models. We have been studying how artificial intelligence techniques can be applied to assist in the development and use of environmental science models within the context of NASA-sponsored activities. We have identified several high-utility areas as potential targets for research and development: model development; data visualization, analysis, and interpretation; model publishing and reuse, training and education; and framing, posing, and answering questions. Central to progress on any of the above areas is a representation for environmental models that contains a great deal more information than is present in a traditional software implementation. In particular, a traditional software implementation is devoid of any semantic information that connects the code with the environmental context that forms the background for the modeling activity. Before we can build AI systems to assist in model development and usage, we must develop a representation for environmental models that adequately describes a model's semantics and explicitly represents the relationship between the code and the modeling task at hand. We have developed one such representation in conjunction with our work on the SIGMA (Scientists' Intelligent Graphical Modeling Assistant) environment. The key feature of the representation is that it provides a semantic grounding for the symbols in a set of modeling equations by linking those symbols to an explicit representation of the underlying environmental scenario.
The current research extends our framework for embodied language and action comprehension to include a teleological representation that allows goal-based reasoning for novel actions. The objective of this work is to implement and demonstrate the advantages of a hybrid, embodied-teleological approach to action–language interaction, both from a theoretical perspective, and via results from human–robot interaction experiments with the iCub robot. We first demonstrate how a framework for embodied language comprehension allows the system to develop a baseline set of representations for processing goal-directed actions such as “take,” “cover,” and “give.” Spoken language and visual perception are input modes for these representations, and the generation of spoken language is the output mode. Moving toward a teleological (goal-based reasoning) approach, a crucial component of the new system is the representation of the subcomponents of these actions, which includes relations between initial enabling states, and final resulting states for these actions. We demonstrate how grammatical categories including causal connectives (e.g., because, if–then) can allow spoken language to enrich the learned set of state-action-state (SAS) representations. We then examine how this enriched SAS inventory enhances the robot's ability to represent perceived actions in which the environment inhibits goal achievement. The paper addresses how language comes to reflect the structure of action, and how it can subsequently be used as an input and output vector for embodied and teleological aspects of action. PMID:10585516
Linking language with embodied and teleological representations of action for humanoid cognition.
The current research extends our framework for embodied language and action comprehension to include a teleological representation that allows goal-based reasoning for novel actions. The objective of this work is to implement and demonstrate the advantages of a hybrid, embodied-teleological approach to action-language interaction, both from a theoretical perspective, and via results from human-robot interaction experiments with the iCub robot. We first demonstrate how a framework for embodied language comprehension allows the system to develop a baseline set of representations for processing goal-directed actions such as "take," "cover," and "give." Spoken language and visual perception are input modes for these representations, and the generation of spoken language is the output mode. Moving toward a teleological (goal-based reasoning) approach, a crucial component of the new system is the representation of the subcomponents of these actions, which includes relations between initial enabling states, and final resulting states for these actions. We demonstrate how grammatical categories including causal connectives (e.g., because, if-then) can allow spoken language to enrich the learned set of state-action-state (SAS) representations. We then examine how this enriched SAS inventory enhances the robot's ability to represent perceived actions in which the environment inhibits goal achievement. The paper addresses how language comes to reflect the structure of action, and how it can subsequently be used as an input and output vector for embodied and teleological aspects of action. PMID:20577629
Representational Task Formats and Problem Solving Strategies in Kinematics and Work
Previous studies have reported that students employed different problem solving approaches when presented with the same task structured with different representations. In this study, we explored and compared students' strategies as they attempted tasks from two topical areas, kinematics and work. Our participants were 19 engineering students taking a calculus-based physics course. The tasks were presented in linguistic, graphical, and symbolic forms and requested either a qualitative solution or a value. The analysis was both qualitative and quantitative in nature focusing principally on the characteristics of the strategies employed as well as the underlying reasoning for their applications. A comparison was also made for the same student's approach with the same kind of representation across the two topics. Additionally, the participants' overall strategies across the different tasks, in each topic, were considered. On the whole, we found that the students prefer manipulating equations irrespective of the representational format of the task. They rarely recognized the applicability of a "qualitative" approach to solve the problem although they were aware of the concepts involved. Even when the students included visual representations in their solutions, they seldom used these representations in conjunction with the mathematical part of the problem. Additionally, the students were not consistent in their approach for interpreting and solving problems with the same kind of representation across the two topical areas. The representational format, level of prior knowledge, and familiarity with a topic appeared to influence their strategies, their written responses, and their ability to recognize qualitative ways to attempt a problem. The nature of the solution does not seem to impact the strategies employed to handle the problem. (Contains 13 figures and 12 tables.)
Media and the making of scientists
This dissertation explores how scientists and science students respond to fictional, visual media about science. I consider how scientists think about images of science in relation to their own career paths from childhood onwards. I am especially interested in the possibility that entertainment media can inspire young people to learn about science. Such inspiration is badly needed, as schools are failing to provide it. Science education in the United States is in a state of crisis. Studies repeatedly find low levels of science literacy in the U.S. This bleak situation exists during a boom in the popularity of science-oriented television shows and science fiction movies. How might entertainment media play a role in helping young people engage with science? To grapple with these questions, I interviewed a total of fifty scientists and students interested in science careers, representing a variety of scientific fields and demographic backgrounds, and with varying levels of interest in science fiction. Most respondents described becoming attracted to the sciences at a young age, and many were able to identify specific sources for this interest. The fact that interest in the sciences begins early in life, demonstrates a potentially important role for fictional media in the process of inspiration, perhaps especially for children without access to real-life scientists. One key aspect to the appeal of fiction about science is how scientists are portrayed as characters. Scientists from groups traditionally under-represented in the sciences often sought out fictional characters with whom they could identify, and viewers from all backgrounds preferred well-rounded characters to the extreme stereotypes of mad or dorky scientists. Genre is another aspect of appeal. Some respondents identified a specific role for science fiction: conveying a sense of wonder. Visual media introduce viewers to the beauty of science. Special effects, in particular, allow viewers to explore the unknown. Advocates of informal science learning initiatives suggest that media can be used as a tool for teaching science content. The potential of entertainment media to provide a sense of wonder is a powerful aspect of its potential to inspire the next generation of scientists.
Perceptual Load Influences Auditory Space Perception in the Ventriloquist Aftereffect
A period of exposure to trains of simultaneous but spatially offset auditory and visual stimuli can induce a temporary shift in the perception of sound location. This phenomenon, known as the "ventriloquist aftereffect", reflects a realignment of auditory and visual spatial representations such that they approach perceptual alignment despite their physical spatial discordance. Such dynamic changes to sensory representations are likely to underlie the brain's ability to accommodate inter-sensory discordance produced by sensory errors (particularly in sound localization) and variability in sensory transduction. It is currently unknown, however, whether these plastic changes induced by adaptation to spatially disparate inputs occurs automatically or whether they are dependent on selectively attending to the visual or auditory stimuli. Here, we demonstrate that robust auditory spatial aftereffects can be induced even in the presence of a competing visual stimulus. Importantly, we found that when attention is directed to the competing stimuli, the pattern of aftereffects is altered. These results indicate that attention can modulate the ventriloquist aftereffect. (Contains 2 tables and 4 figures.)
Deciding How to Act Is Not Achieved by Watching Mental Movies
In the early days of research on visual imagery, it was believed that visual images are like pictures in one's head. Only as the field matured did it come to be appreciated that visual images do not bear a first-order isomorphic relation to visual percepts. Now that the early days of research on motor imagery are coming to an end, it is important to ask whether motor images bear a first-order isomorphic relation to movements. We asked whether they do by focusing on internal simulations for motor planning. Our participants indicated which of two possible actions they preferred either by performing the preferred action or by indicating which action they would prefer to perform. We reasoned that if internal simulations of physical actions bear a first-order isomorphic relation to actual physical actions, the choices would be the same in the two conditions. They were not. We discuss the reasons for this outcome, including the adaptive advantage of a representational system for action which, like the representational system for vision, does not bear a first-order isomorphic relation to its external analog. (Contains 6 figures.)
The visual system is able to represent and integrate large amounts of information as we move our gaze across a scene. This process, called spatial remapping, enables the construction of a stable representation of our visual environment despite constantly changing retinal images. Converging evidence implicates the parietal lobes in this process, with the right hemisphere having a dominant role. Indeed, lesions to the right parietal lobe (e.g., leading to hemispatial neglect) frequently result in deficits in spatial remapping. Research has demonstrated that recalibrating visual, proprioceptive and motor reference frames using prism adaptation ameliorates neglect symptoms and induces neglect-like performance in healthy people - one example of the capacity for rapid neural plasticity in response to new sensory demands. Because of the influence of prism adaptation on parietal functions, the present research investigates whether prism adaptation alters spatial remapping in healthy individuals. To this end twenty-eight undergraduates completed blocks of a double-step saccade (DSS) task after sham adaptation and adaptation to leftward- or rightward-shifting prisms. The results were consistent with an impairment in spatial remapping for left visual field targets following adaptation to leftward-shifting prisms. These results suggest that temporarily realigning spatial representations using sensory-motor adaptation alters right-hemisphere remapping processes in healthy individuals. The implications for the possible mechanisms of the amelioration of hemispatial neglect after prism adaptation are discussed. PMID:22386659
Paint4Net: COBRA Toolbox extension for visualization of stoichiometric models of metabolism.
A visual analysis of reconstructions and large stoichiometric models with elastic change of the visualization scope and representation methods becomes increasingly important due to the rapidly growing size and number of available reconstructions. The Paint4Net is a novel COBRA Toolbox extension for automatic generation of a hypergraph layout of defined scope with the steady state rates of reaction fluxes of stoichiometric models. Directionalities and fluxes of reactions are constantly represented in the visualization while detailed information about reaction (ID, name and synonyms, and formula) and metabolite (ID, name and synonyms, and charged formula) appears placing the cursor on the item of interest. Additionally Paint4Net functionality can be used to: (1) get lists of involved metabolites and dead end metabolites of the visualized part of the network, (2) exclude (filter) particular metabolites from representation, (3) find isolated parts of a network and (4) find running cycles when all the substrates are cut down. Layout pictures can be saved in various formats and easily distributed. The Paint4Net is open source software under the GPL v3 license. Relevant documentation and sample data is available at http://www.biosystems.lv/paint4net. The Paint4Net works on MATLAB starting from version of 2009. PMID:22446067
CloudLines: compact display of event episodes in multiple time-series.
We propose incremental logarithmic time-series technique as a way to deal with time-based representations of large and dynamic event data sets in limited space. Modern data visualization problems in the domains of news analysis, network security and financial applications, require visual analysis of incremental data, which poses specific challenges that are normally not solved by static visualizations. The incremental nature of the data implies that visualizations have to necessarily change their content and still provide comprehensible representations. In particular, in this paper we deal with the need to keep an eye on recent events together with providing a context on the past and to make relevant patterns accessible at any scale. Our technique adapts to the incoming data by taking care of the rate at which data items occur and by using a decay function to let the items fade away according to their relevance. Since access to details is also important, we also provide a novel distortion magnifying lens technique which takes into account the distortions introduced by the logarithmic time scale to augment readability in selected areas of interest. We demonstrate the validity of our techniques by applying them on incremental data coming from online news streams in different time frames. PMID:22034364
Abstract in spanish Explorar la representación gráfica vía la interpretación global permite establecer modificaciones en la expresión algebraica para identificar su correspondiente variable visual en la gráfica, lo que concede asociar una variable visual con una variable categórica en la expresión algebraica, favoreciendo la articulación entre dichas variables. Sin embargo, desarrollar la interpretación global en polinomios de grado mayor que dos parece ser una tarea compleja, debi (more) do al comportamiento del trazo, lo que complica identificar e interpretar las correspondientes variables visuales que experimentan múltiples variaciones. Frente a esta problemática, se propuso una alternativa orientada a explorar cualitativa y cuantitativamente el trazo para identificar las "características visuales", información que se enriqueció con la representación numérica, lo que permitió identificar el contenido de la parábola y el trazo cúbico. Esta propuesta se implementó en dos grupos del nivel medio superior que cursaban la asignatura de álgebra (15 a 16 años); la finalidad de la investigación es el análisis de las estrategias que el alumno emplea cuando ha tenido la vivencia de explorar las representaciones gráfica, numérica, y algebraica vía la interpretación global en situaciones que demandan la construcción de la expresión algebraica de una gráfica (recta, parábola y cúbica). Durante la experiencia, los alumnos contaron con el apoyo del software Cabri géomètre para realizar las tareas diseñadas. Abstract in english Exploring the graphical representation by means of the Global Interpre-tation allows to establish modifications in the algebraic expression to identify the corresponding visual variable in the graphic, allowing the association of a visual variable within the algebraic expression, contributing to the articulation between such variables. However, developing the global interpretation in polynomials of higher degree than two seems to be a complex task because of the behavior (more) of the trace which makes difficult to identify and interpret the corresponding visual variables that experiment multiple variations. To overcome this problem an alternative was proposed oriented to explore in a qualitative and quantitative way traces to identify the "visual characteristics", information that is enriched with the numerical representation; this allows to identify the content of the parabola and the cubic trace. This proposal was applied in two high-school groups, where students were studying an algebra course (15 to 16 year-old students). The objective of this research is the analysis of the strategies that the students employed when they have had the experience to explore the graphic, numeric and algebraic representations using the global interpretation in situations that demand the construction of the algebraic expression in a graph (straight line, parabola and cubic). During the experience, the students employed the dynamic software Cabry géomètry to do the designed tasks.
BrainVoyager - Past, present, future
BrainVoyager started as a simple fMRI analysis tool in the mid 1990s; the software was primarily created to fulfill the needs of its author and his colleagues to analyze anatomical and functional MRI data in a way that would be most appropriate for their research questions in visual and auditory perception. More specifically, the software was designed with three major goals in mind. First, it should allow analyses that would exploit optimally the high-resolution information available in fMRI data. Second, it should integrate volume-based analysis and cortex-based analysis including the possibility to visualize topographic activation data on flattened cortex representations. Third, it should combine hypothesis testing with data-driven analysis including interactive visualization tools that ...
Teaching Science Through Pictorial Models During Read-Alouds
This study examines how three elementary teachers refer to pictorial models (photographs, drawings, and cartoons) during science read-alouds. While one teacher used realistic photographs for the purpose of visually verifying facts about crystals, another employed analytical diagrams as heuristic tools to help students visualize complex target systems (rainbow formation and human eye functioning). Another teacher used fictional cartoons to engage students in analogical storytelling, communicating animal camouflage as analogous to human "blending in." However, teachers did not always explicitly convey the representational nature of pictorial models (analog and target as separate entities). It is argued that teachers need to become more aware of how they refer to pictorial models in children's science books and how to promote student visual literacy.
Facilitating Understanding of Movements in Dynamic Visualizations: An Embodied Perspective
Learners studying mechanical or technical processes via dynamic visualizations often fail to build an accurate mental representation of the system's movements. Based on embodied theories of cognition assuming that action, perception, and cognition are closely intertwined, this paper proposes that the learning effectiveness of dynamic visualizations could be enhanced by grounding the movements of the presentation in people's own bodily experiences during learning. We discuss recent research on embodied cognition and provide specific strategies for how the body can be used to ground movements during the learning process: (1) making or observing gestures, (2) manipulating and interacting with objects, (3) using body metaphors, and (4) using eye movements as retrieval cues. Implications for the design of dynamic visualizations as well as directions for future research are presented.
A Proposal for a BBS with Visual Presentation for Online Data Analysis
The concept of a bulletin board system (BBS) equipped with information visualization techniques is proposed for supporting online data analysis. Although group discussion is known to be effective for analyzing data from various viewpoints, the number of participants is limited by time and space constraints. To solve that problem, this paper proposes to augment a BBS, a popular web based tool. In order for discussion participants to share data online, the system provides them with a visual representation of target data, which elicits comments from participants as well as compares these comments. In order to illustrate the concept's potential, a BBS equipped with KeyGraph is also developed for supporting online chance discovery. It has functions for making visual annotations on the KeyGraph as well as a function for retrieving similar scenarios. The experimental results show the effectiveness of the BBS in terms of the usefulness of scenario generation support functions as well as that of scenario retrieval engines.
Spatio-temporal dynamics of attention to color: evidence from human electrophysiology
On cross-modal interactions, top-down controls such as attention and explicit identification of cross-modal inputs were assumed to play crucial roles for the optimization. Here we show the establishment of cross-modal associations without such top-down controls. The onsets of two circles producing apparent motion perception were accompanied by indiscriminable sounds consisting of six identical and one unique sound frequencies. After adaptation to the visual apparent motion with the sounds, the sounds acquired a driving effect for illusory visual apparent motion perception. Moreover, the pure tones with each unique frequency of the sounds acquired the same effect after the adaptation, indicating that the difference in the indiscriminable sounds was implicitly coded. We further confrimed that the aftereffect didnot transfer between eyes. These results suggest that the brain establishes new neural representations between sound frequency and visual motion without clear identification of the specific relationship between cross-modal stimuli in early perceptual processing stages. PMID:9704262
Abstract in english In this paper, the topology of cortical visuotopic maps in adult primates is reviewed, with emphasis on recent studies. The observed visuotopic organisation can be summarised with reference to two basic rules. First, adjacent radial columns in the cortex represent partially overlapping regions of the visual field, irrespective of whether these columns are part of the same or different cortical areas. This primary rule is seldom, if ever, violated. Second, adjacent regions (more) of the visual field tend to be represented in adjacent radial columns of a same area. This rule is not as rigid as the first, as many cortical areas form discontinuous, second-order representations of the visual field. A developmental model based on these physiological observations, and on comparative studies of cortical organisation, is then proposed, in order to explain how a combination of molecular specification steps and activity-driven processes can generate the variety of visuotopic organisations observed in adult cortex.
The role of visual representations for structuring classroom mathematical activity
It is our presupposition that there is still a need for more research about how classroom practices can exploit the use and power of visualization in mathematics education. The aim of this article is to contribute in this direction, investigating how visual representations can structure geometry activity in the classroom and discussing teaching practices that can facilitate students? visualization of mathematical objects. We present one illustrative episode that shows how drawings of geometrical figures have a powerful role in structuring and modifying the mathematical activity in the classroom. It was selected from a database that we have been building to investigate the learning of mathematics in public elementary schools in Brazil. The framework of Activity Theory helped in the characte...
Learning to attend and to ignore is a matter of gains and losses.
Efficient goal-directed behavior in a crowded world is crucially mediated by visual selective attention (VSA), which regulates deployment of cognitive resources toward selected, behaviorally relevant visual objects. Acting as a filter on perceptual representations, VSA allows preferential processing of relevant objects and concurrently inhibits traces of irrelevant items, thus preventing harmful distraction. Recent evidence showed that monetary rewards for performance on VSA tasks strongly affect immediately subsequent deployment of attention; a typical aftereffect of VSA (negative priming) was found only following highly rewarded selections. Here we report a much more striking demonstration that the controlled delivery of monetary rewards also affects attentional processing several days later. Thus, the propensity to select or to ignore specific visual objects appears to be strongly biased by the more or less rewarding consequences of past attentional encounters with the same objects. PMID:19422618
A three-dimensional (3D) visualization technique was developed to visualize the distributions of protein and starch inside the whole body of a brown rice grain. The automatic precision microtome system that was developed for microscopy was applied to obtain sections from the whole body of a single grain. The obtained sections were sequentially adhered onto a specialized adhesive tape for 3D reconstruction. All sections were stained by a chemical technique to visualize the protein and starch. Each stained section was digitally imaged using a color charge-coupled device (CCD) camera. The two-dimensional (2D) digital images contained the color information representing protein and starch. A 3D image of the whole body of a brown rice grain was reconstructed by accumulating the 2D digital images in a personal computer. A three-dimensional representation of the distributions of protein and starch in a grain of brown rice was thus constructed.
A visual inquiry into ethics and change
Purpose - The purpose of this paper is to introduce the practices and findings of a visual inquiry developed by the co-authors with students in a Business School in the south west of England. The authors are interested in how students engaged with the visual as a practice of inquiry and how this contributed to their development of a critical approach to the concept of ethics in business organisations. Design/methodology/approach - Students visited an exhibition shown as part of the 100 days countdown to the COP15 UN climate change conference, and constructed visual representation of questions and dilemmas related to ethical business practice. The analysis focuses on student presentations, and the discussions that these provoked on the relationship between "business" and "ethical practice"....
Three-dimensional visual feature representation in the primary visual cortex
In the cat primary visual cortex, it is accepted that neurons optimally responding to similar stimulus orientations are clustered in a column extending from the superficial to deep layers. The cerebral cortex is, however, folded inside a skull, which makes gyri and fundi. The primary visual area of cats, area 17, is located on the fold of the cortex called the lateral gyrus. These facts raise the question of how to reconcile the tangential arrangement of the orientation columns with the curvature of the gyrus. In the present study, we show a possible configuration of feature representation in the visual cortex using a three-dimensional (3D) self-organization model. We took into account preferred orientation, preferred direction, ocular dominance and retinotopy, assuming isotropic interacti...
Alpha-1 Adrenergic Receptors Gate Rapid Orientation-Specific Reduction in Visual Discrimination
Prolonged imbalance in sensory experience leads to dramatic readjustments in cortical representation. Neuromodulatory systems play a critical role in habilitating experience-induced plasticity and regulate memory processes in vivo. Here, we show that a brief period of intense patterned visual stimulation combined with systemic activation of alpha-1 adrenergic neuromodulator receptors (a1-ARs) leads to a rapid, reversible, and NMDAR-dependent depression of AMPAR-mediated transmission from ascending inputs to layer II/III pyramidal cells in the visual cortex of young and adult mice. The magnitude of this form of a1-AR long-term depression (LTD), measured ex vivo with miniature EPSC recordings, is graded by the number of orientations used during visual experience. Moreover, behavioral tests o...
CLPGUI a generic graphical user interface for constraint logic programming over finite domains
CLPGUI is a graphical user interface for visualizing and interacting with constraint logic programs over finite domains. In CLPGUI, the user can control the execution of a CLP program through several views of constraints, of finite domain variables and of the search tree. CLPGUI is intended to be used both for teaching purposes, and for debugging and improving complex programs of realworld scale. It is based on a client-server architecture for connecting the CLP process to a Java-based GUI process. Communication by message passing provides an open architecture which facilitates the reuse of graphical components and the porting to different constraint programming systems. Arbitrary constraints and goals can be posted incrementally from the GUI. We propose several dynamic 2D and 3D visualizations of the search tree and of the evolution of finite domain variables. We argue that the 3D representation of search trees proposed in this paper provides the most appropriate visualization of large search trees. We descr...
A Regularized Graph Layout Framework for Dynamic Network Visualization
Many real-world networks, including social and information networks, are dynamic structures that evolve over time. Such dynamic networks are typically visualized using a sequence of static graph layouts. In addition to providing a visual representation of the network topology at each time step, the sequence should preserve the mental map between layouts of consecutive time steps to allow a human to interpret the temporal evolution of the network. In this paper, we propose a framework for dynamic network visualization using regularized graph layouts. Regularization encourages stability of the layouts over time, thus preserving the mental map. The proposed framework involves optimizing a modified cost function that augments the cost function of a static graph layout algorithm with a grouping penalty, which encourages nodes to stay close to other nodes belonging to the same group, and a temporal penalty, which encourages smooth movements of the nodes over time. We introduce two dynamic layout algorithms under th...
Memory for perceptual events includes the neural representation of the sensory information at short or longer time scales. Recent transcranial magnetic stimulation (TMS) studies of human visual cortex provided evidence that sensory cortex contributes to memory functions. In this review, we provide an exhaustive overview of these studies and ascertain how well the available evidence supports the idea of a causal role of sensory cortex in memory retention and retrieval. We discuss the validity and implications of the studies using a number of methodological and theoretical criteria that are relevant for brain stimulation of visual cortex. While most studies applied TMS to visual cortex to interfere with memory functions, a handful of pioneering studies used TMS to 'reactivate' memories in vi...
Modeling Bottom-Up Visual Attention for Color Images
Modeling visual attention provides an alternative methodology to image description in many applications such as adaptive content delivery and image retrieval. In this paper, we propose a robust approach to the modeling bottom-up visual attention. The main contributions are twofold: 1) We use a principal component analysis (PCA) to transform the RGB color space into three principal components, which intrinsically leads to an opponent representation of colors to ensure good saliency analysis. 2) A practicable framework for modeling visual attention is presented based on a region-level reliability analysis for each feature map. And then the salient map can be robustly generated for a variety of nature images. Experiments show that the proposed algorithm is effective and can characterize the human perception well.
In this article we consider the implications of using popular visual media as a pedagogic tool for helping teachers acquire critical sociocultural knowledge to work more effectively with students of color, particularly Black males. Drawing from a textual analysis (McKee 2001, 2003; Rose 2001) conducted in the critical visual studies tradition (Barthes 1977; Hall 1993, 1997) and longstanding discourses on Blackness, Black masculinity and critical visual studies, we explore how the critically acclaimed HBO series, The Wire, positions Black males in the local and larger social milieu. While offering a more complex rendering of the Black male, The Wire simultaneously presents a myopic representation of the Black man and his place in the larger Black community. This inquiry highlights the pedag...
The Automaticity of Visual Statistical Learning
The visual environment contains massive amounts of information involving the relations between objects in space and time, and recent studies of visual statistical learning (VSL) have suggested that this information can be automatically extracted by the visual system. The experiments reported in this article explore the automaticity of VSL in several ways, using both explicit familiarity and implicit response-time measures. The results demonstrate that (a) the input to VSL is gated by selective attention, (b) VSL is nevertheless an implicit process because it operates during a cover task and without awareness of the underlying statistical patterns, and (c) VSL constructs abstracted representations that are then invariant to changes in extraneous surface features. These results fuel the conclusion that VSL both is and is not automatic: It requires attention to select the relevant population of stimuli, but the resulting learning then occurs without intent or awareness.
Uniform signal redundancy of parasol and midget ganglion cells in primate retina.
The collective representation of visual space in high resolution visual pathways was explored by simultaneously measuring the receptive fields of hundreds of ON and OFF midget and parasol ganglion cells in isolated primate retina. As expected, the receptive fields of all four cell types formed regular mosaics uniformly tiling the visual scene. Surprisingly, comparison of all four mosaics revealed that the overlap of neighboring receptive fields was nearly identical, for both the excitatory center and inhibitory surround components of the receptive field. These observations contrast sharply with the large differences in the dendritic overlap between the parasol and midget cell populations, revealing a surprising lack of correspondence between the anatomical and functional architecture in the dominant circuits of the primate retina. PMID:19357292
State of the Art Report on Video-Based Graphics and Video Visualization
Abstract In recent years, a collection of new techniques which deal with video as input data, emerged in computer graphics and visualization. In this survey, we report the state of the art in video-based graphics and video visualization. We provide a review of techniques for making photo-realistic or artistic computer-generated imagery from videos, as well as methods for creating summary and/or abstract visual representations to reveal important features and events in videos. We provide a new taxonomy to categorize the concepts and techniques in this newly emerged body of knowledge. To support this review, we also give a concise overview of the major advances in automated video analysis, as some techniques in this field (e.g. feature extraction, detection, tracking and so on) have been fea...
Unintentional temporal context-based prediction of emotional faces: an electrophysiological study.
The ability to extract sequential regularities embedded in the temporal context or temporal structure of sensory events and to predict upcoming events based on the extracted sequential regularities plays a central role in human cognition. In the present study, we demonstrate that, without any intention, upcoming emotional faces can be predicted based on sequential regularities, by showing that prediction error responses as reflected by visual mismatch negativity (MMN), an event-related brain potential (ERP) component, were evoked in response to emotional faces that violated a regular alternation pattern of 2 emotional faces (fearful and happy faces) under a situation where the emotional faces themselves were unrelated to the participant's task. Face-inversion and negative-bias effects in the visual MMN further indicated the involvement of holistic face representations. In addition, through successive source analyses of the visual MMN, it was revealed that the prediction error responses were composed of activations mainly in the face-responsible visual extrastriate areas and the prefrontal areas. The present results provide primary evidence for the existence of the unintentional temporal context-based prediction of biologically relevant visual stimuli as well as empirical support for the major engagement of the visual and prefrontal areas in unintentional temporal context-based prediction in vision. PMID:21945904
Exploitation of natural geometrical regularities facilitates target detection.
We have evolved to operate within a dynamic visual world in which natural visual signals are not random but have various statistical regularities. Our rich experience of the probability structure of these regularities could influence visual computation. Considering that spatiotemporal regularity, co-linearity and co-circularity are common geometrical regularities in natural scenes, we explored how our visual system exploits these regularities to achieve accurate and efficient representations of the external world. By measuring human contrast detection performance of a briefly presented foveal target embedded in dynamic stimulus sequences (comprising six short bars appearing consecutively towards the fovea) imitating common regularity structures, we found that both contrast sensitivity and reaction time for target detection was facilitated by predictable spatiotemporal stimulus structure. Qualitatively consistent with natural image analysis that co-linearity is a stronger statistical feature than co-circularity, the facilitation in target detection was more evident for predictable stimulus sequences following a co-linear path than a co-circular path. Control experiments further showed that response bias and uncertainty reduction could not fully account for our observation. It seems that our visual system exploits geometrical natural regularities to facilitate the interpretation of incoming visual signals, such as constraining interpretation on the basis of contextual priors. PMID:20850468
GPU-based interactive cut-surface extraction from high-order finite element fields.
We present a GPU-based ray-tracing system for the accurate and interactive visualization of cut-surfaces through 3D simulations of physical processes created from spectral/hp high-order finite element methods. When used by the numerical analyst to debug the solver, the ability for the imagery to precisely reflect the data is critical. In practice, the investigator interactively selects from a palette of visualization tools to construct a scene that can answer a query of the data. This is effective as long as the implicit contract of image quality between the individual and the visualization system is upheld. OpenGL rendering of scientific visualizations has worked remarkably well for exploratory visualization for most solver results. This is due to the consistency between the use of first-order representations in the simulation and the linear assumptions inherent in OpenGL (planar fragments and color-space interpolation). Unfortunately, the contract is broken when the solver discretization is of higher-order. There have been attempts to mitigate this through the use of spatial adaptation and/or texture mapping. These methods do a better job of approximating what the imagery should be but are not exact and tend to be view-dependent. This paper introduces new rendering mechanisms that specifically deal with the kinds of native data generated by high-order finite element solvers. The exploratory visualization tools are reassessed and cast in this system with the focus on image accuracy. This is accomplished in a GPU setting to ensure interactivity. PMID:22034297
Supporting Computational Visual Theories in Biology
At the Pacific Northwest National Laboratory, the Visual Modeling Environment for Biology (VMEB) is being developed to allow biologists to construct visual representations of scientific concepts and theories. Unlike existing scientific visual modeling environments, VMEB captures and manages visual concepts and diagrams in a computational form that may be transferred across sessions, shared among collaborators, linked to external data sources, and searched against to identify relevant or matching information. VMEB captures not only generated graphical objects and their spatial relationships, but also the underlying biological meanings of those objects as defined by biologists. The biological meanings are translated into graphical rules that are saved to a rules base. With a set of rules, VMEB may then automatically identify and attach biological meaning to graphical objects and patterns as they are constructed if those objects and patterns match existing entries in the rules base. The collection of graphical rules constitutes an underlying visual language built upon emerging user-defined symbols and concepts. As such, the visual language dynamically evolves along with the biological theory under investigation.
Memory for perceptual events includes the neural representation of the sensory information at short or longer time scales. Recent transcranial magnetic stimulation (TMS) studies of human visual cortex provided evidence that sensory cortex contributes to memory functions. In this review, we provide an exhaustive overview of these studies and ascertain how well the available evidence supports the idea of a causal role of sensory cortex in memory retention and retrieval. We discuss the validity and implications of the studies using a number of methodological and theoretical criteria that are relevant for brain stimulation of visual cortex. While most studies applied TMS to visual cortex to interfere with memory functions, a handful of pioneering studies used TMS to 'reactivate' memories in visual cortex. Interestingly, similar effects of TMS on memory were found in different memory tasks, which suggests that different memory systems share a neural mechanism of memory in visual cortex. At the same time, this neural mechanism likely interacts with higher order brain areas. Based on this overview and evaluation, we provide a first attempt to an integrative framework that describes how sensory processes contribute to memory in visual cortex, and how higher order areas contribute to this mechanism. PMID:22921373
The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily presented words and either meaningless objects or locations in a 3-D space. During the retrieval phase one day later, participants had to decide whether two auditorily presented words shared an association with a common object or location. Thus, perceptual stimulation during retrieval was always equivalent, whereas either visually or haptically encoded object or location associations had to be reactivated. Moreover, the number of associations fanning out from each word varied systematically, enabling a parametric increase of the number of reactivated representations. Recall of visual objects predominantly activated the left superior frontal gyrus and the intraparietal cortex, whereas visually learned locations activated the superior parietal cortex of both hemispheres. Retrieval of haptically encoded material activated the left medial frontal gyrus and the intraparietal cortex in the object condition, and the bilateral superior parietal cortex in the location condition. A direct test for modality-specific effects showed that visually encoded material activated more vision-related areas (BA 18/19) and haptically encoded material more motor and somatosensory-related areas. A conjunction analysis identified supramodal and material-unspecific activations within the medial and superior frontal gyrus and the superior parietal lobe including the intraparietal sulcus. These activation patterns strongly support the idea that code-specific representations are consolidated and reactivated within anatomically distributed cell assemblies that comprise sensory and motor processing systems.
Abstract in spanish El cine ficción es uno de los medios de comunicación visual de mayor influencia en la circulación de valores y creencias en el mundo contemporáneo. Se trata de una práctica cultural de extremo control, planificación y manipulación audiovisual que ha permanecido en los márgenes de la preocupación antropológica. Sin embargo, nuevos intereses relativos a la comprensión de los modos de ver nos han permitido indagar con cierta profundidad en el funcionamiento de est (more) e dominio y sus artefactos visuales. En el presente artículo se describen los dispositivos y procedimientos visuales relativos al cine ficción chileno, en particular aquel que ha introducido en sus obras de modo protagónico la imagen de los nativos de Chile. Nuestros resultados sugieren la presencia de una estrategia cultural cuyas representaciones sólo tratan formalmente con la diversidad cultural, un recurso audiovisual que ha favorecido el establecimiento de un modo utópico de imaginar al "otro" y su mundo social. Abstract in english The cinema is one ofthe visual media ofmore influence in the circulation of valúes and beliefs in the contemporary world. It is a cultural practice that has remained in the margins ofthe anthropology. However, new relative interests to the understanding in the ways of seeing, it has allowed us to investígate with certain depth in the operations ofthis domain and their visual devices. This article described the devices and visual procedures to native representations a Ch (more) ilean cinema fiction. Our results suggest the presence a cultural strategy whose representations don 't try with the cultural diversity, but rather they appear as a utopian way of imagining the social world.
The OpenEarth Framework (OEF) for the 3D Visualization of Integrated Earth Science Data
Data integration is increasingly important as we strive to combine data from disparate sources and assemble better models of the complex processes operating at the Earth's surface and within its interior. These data are often large, multi-dimensional, and subject to differing conventions for data structures, file formats, coordinate spaces, and units of measure. When visualized, these data require differing, and sometimes conflicting, conventions for visual representations, dimensionality, symbology, and interaction. All of this makes the visualization of integrated Earth science data particularly difficult. The OpenEarth Framework (OEF) is an open-source data integration and visualization suite of applications and libraries being developed by the GEON project at the University of California, San Diego, USA. Funded by the NSF, the project is leveraging virtual globe technology from NASA's WorldWind to create interactive 3D visualization tools that combine and layer data from a wide variety of sources to create a holistic view of features at, above, and beneath the Earth's surface. The OEF architecture is open, cross-platform, modular, and based upon Java. The OEF's modular approach to software architecture yields an array of mix-and-match software components for assembling custom applications. Available modules support file format handling, web service communications, data management, user interaction, and 3D visualization. File parsers handle a variety of formal and de facto standard file formats used in the field. Each one imports data into a general-purpose common data model supporting multidimensional regular and irregular grids, topography, feature geometry, and more. Data within these data models may be manipulated, combined, reprojected, and visualized. The OEF's visualization features support a variety of conventional and new visualization techniques for looking at topography, tomography, point clouds, imagery, maps, and feature geometry. 3D data such as seismic tomography may be sliced by multiple oriented cutting planes and isosurfaced to create 3D skins that trace feature boundaries within the data. Topography may be overlaid with satellite imagery, maps, and data such as gravity and magnetics measurements. Multiple data sets may be visualized simultaneously using overlapping layers within a common 3D coordinate space. Data management within the OEF handles and hides the inevitable quirks of differing file formats, web protocols, storage structures, coordinate spaces, and metadata representations. Heuristics are used to extract necessary metadata used to guide data and visual operations. Derived data representations are computed to better support fluid interaction and visualization while the original data is left unchanged in its original form. Data is cached for better memory and network efficiency, and all visualization makes use of 3D graphics hardware support found on today's computers. The OpenEarth Framework project is currently prototyping the software for use in the visualization, and integration of continental scale geophysical data being produced by EarthScope-related research in the Western US. The OEF is providing researchers with new ways to display and interrogate their data and is anticipated to be a valuable tool for future EarthScope-related research.
3D city models are mostly seen as static or at least as background for various animations types. In the last couple of years, experts have realized that 3D city models (technical maps of the future) should be maintained in order to be used in a continuous and dynamical planning and administration. Therefore it is important that temporal information is attached to the different parts of a city model so that it can be used as part of metadata for city models. Another and just as important use of time is related to the temporal characteristics of the 3D city models. There is a huge difference between traditional static city models and those models that are built for realtime applications. The difference between the city models applies both to the spatial modelling and also when using the phenomenon time in the models. If the city models are used in visualizations without any variation in time or when the variation in time is non-synchronous with real-time, usually more effort can be put on the fi delity in relation to the aesthetic and geometric representation. This means that the models are more realistic or contain another level of detail. However, if one looks at virtual environments with an in-built dynamic or a model suitable for visualization in realtime, it is required that modelling is done with level-of-detail and simplification of both the aesthetics and the geometry. If a temporal characteristic is combined with a visual characteristic, the situation can easily be seen as a t/v matrix where t is the temporal characteristic or representation and v is the visual characteristic or representation.
Coronarography and tomo-scintigraphy (SPECT, Single Photon Emission Tomography) are two imaging techniques used broadly for the diagnosis of cardiovascular diseases. The first modality consists of X-ray image sequences visualizing each, in a same plane, the coronary arteries located on the front and the back side of the heart. The X-ray images give anatomical information relating to the arterial tree and highlight eventual artery narrowing (stenoses). The SPECT modality (nuclear imaging) provide a 3-dimensional (3D) representation of the myocardial volume perfusion. This functional information authorizes the visualization of myocardial regions suffering from irrigation defaults. The aim of the presented work is to superimpose (in the 3D space) the functional and anatomical information in order to establish the visual link between arterial lesions and their consequence in terms of irrigation defaults. In the 3D representation chosen to facilitate the diagnosis, the structure of a schematic arterial tree and the stenoses are placed onto the perfusion volume. The initial data consist of a list of points representative for the arterial tree (start and end points of arterial segments, bifurcations, stenoses, etc) and marked by coronary-graphs on the X-ray images of the different incidences. The perfusion volume is then projected under the incidences of the coronary-graphic images. A registration algorithm superimposing the X-ray images and the corresponding SPECT projections provides the parameters of the geometrical transformations bringing the points marked in the X rays images in equivalent positions in the 2-dimensional SPECT images. A 3D reconstruction algorithm is then used to place the arterial points and the stenoses on the perfusion volume and build a schematic tree acting as landmark for the clinician. A 28 patient database was used to realize 40 3D superimposition of anatomical-functional data. These reconstructions have shown that the 3D representation is precise enough for the establishment of the visual relationship between stenoses and perfusion defaults. (author)
A team consisting of Teledyne Scientific Company, the University of California at Santa Barbara and the Army Research Laboratory* is developing technologies in support of automated data exfiltration from heterogeneous battlefield sensor networks to enhance situational awareness for dismounts and command echelons. Unmanned aerial vehicles (UAV) provide an effective means to autonomously collect data from a sparse network of unattended ground sensors (UGSs) that cannot communicate with each other. UAVs are used to reduce the system reaction time by generating autonomous collection routes that are data-driven. Bio-inspired techniques for search provide a novel strategy to detect, capture and fuse data. A fast and accurate method has been developed to localize an event by fusing data from a sparse number of UGSs. This technique uses a bio-inspired algorithm based on chemotaxis or the motion of bacteria seeking nutrients in their environment. A unique acoustic event classification algorithm was also developed based on using swarm optimization. Additional studies addressed the problem of routing multiple UAVs, optimally placing sensors in the field and locating the source of gunfire at helicopters. A field test was conducted in November of 2009 at Camp Roberts, CA. The field test results showed that a system controlled by bio-inspired software algorithms can autonomously detect and locate the source of an acoustic event with very high accuracy and visually verify the event. In nine independent test runs of a UAV, the system autonomously located the position of an explosion nine times with an average accuracy of 3 meters. The time required to perform source localization using the UAV was on the order of a few minutes based on UAV flight times. In June 2011, additional field tests of the system will be performed and will include multiple acoustic events, optimal sensor placement based on acoustic phenomenology and the use of the International Technology Alliance (ITA) Sensor Network Fabric (IBM).
Overcoming the guidance effect in motor skill learning: feedback all the time can be beneficial.
Extensive research has shown that augmented feedback presented too often can create a dependency on the feedback and hinder long-term memory formation of a motor skill. This dependency has been labeled the guidance effect, and one way to overcome the guidance effect is to reduce how often augmented feedback is presented during training. In two experiments, participants were presented with visual augmented feedback during every trial in a 5-min training interval. Participants were provided visual augmented feedback in the form of a Lissajous template of a 1:2 multi-frequency pattern and a cursor representing the coordination between the limbs. Some participants were trained with the cursor superimposed (behind group) on the Lissajous template, and others were trained with the cursor presented in a separate window (side group) from the Lissajous template. In experiment 1, motion of the end-effectors was constrained to the medial-lateral direction in the horizontal plane. In experiment 2, end-effector motion was possible in both the medial-lateral and anterior-posterior directions in the horizontal plane. The location of the cursor did not influence performance during the 5-min training interval in either experiment. After a 15-min break, a retention test performed without the visual feedback provided by the cursor revealed that the behind groups' performance was guided by the visual feedback in both experiments, whereas the side groups were able to perform without visual feedback. In experiment two, the side group's performance without feedback was influenced when anterior-posterior motion was not constrained; however, the extent of the guidance effect was significantly less compared to the behind trained group in both experiments. The results show that the emergence of guided motor performance depends on the format of the display that provides visually based augmented feedback, and not just on how often the feedback is provided. In conclusion, visually based augmented feedback leads to the simultaneous development of a spatial and motor representation of the task. The behind format led to a dependence on the spatial representation developed during training, while the side format facilitated the development of the motor representation as a means to overcome guidance. PMID:22526952
Data Fusion and Visualization with the OpenEarth Framework (OEF)
Data fusion is an increasingly important problem to solve as we strive to integrate data from multiple sources and build better models of the complex processes operating at the Earth’s surface and its interior. These data are often large, multi-dimensional, and subject to differing conventions for file formats, data structures, coordinate spaces, units of measure, and metadata organization. When visualized, these data require differing, and often conflicting, conventions for visual representations, dimensionality, icons, color schemes, labeling, and interaction. These issues make the visualization of fused Earth science data particularly difficult. The OpenEarth Framework (OEF) is an open-source data fusion and visualization suite of software being developed at the Supercomputer Center at the University of California, San Diego. Funded by the NSF, the project is leveraging virtual globe technology from NASA’s WorldWind to create interactive 3D visualization tools that combine layered data from a variety of sources to create a holistic view of features at, above, and beneath the Earth’s surface. The OEF architecture is cross-platform, multi-threaded, modular, and based upon Java. The OEF’s modular approach yields a collection of compatible mix-and-match components for assembling custom applications. Available modules support file format handling, web service communications, data management, data filtering, user interaction, and 3D visualization. File parsers handle a variety of formal and de facto standard file formats. Each one imports data into a general-purpose data representation that supports multidimensional grids, topography, points, lines, polygons, images, and more. From there these data then may be manipulated, merged, filtered, reprojected, and visualized. Visualization features support conventional and new visualization techniques for looking at topography, tomography, maps, and feature geometry. 3D grid data such as seismic tomography may be sliced by multiple oriented cutting planes and isosurfaced to create 3D skins that trace feature boundaries within the data. Topography may be overlaid with satellite imagery along with data such as gravity and magnetics measurements. Multiple data sets may be visualized simultaneously using overlapping layers and a common 3D+time coordinate space. Data management within the OEF handles and hides the quirks of differing file formats, web protocols, storage structures, coordinate spaces, and metadata representations. Derived data are computed automatically to support interaction and visualization while the original data is left unchanged in its original form. Data is cached for better memory and network efficiency, and all visualization is accelerated by 3D graphics hardware found on today’s computers. The OpenEarth Framework project is currently prototyping the software for use in the visualization, and integration of continental scale geophysical data being produced by EarthScope-related research in the Western US. The OEF is providing researchers with new ways to display and interrogate their data and is anticipated to be a valuable tool for future EarthScope-related research.
In spite of its success, the standard 2-D discrete wavelet transform (2D-DWT) is not completely adapted to represent image entities like edges or oriented textures. Indeed the DWT is limited by the spatial isotropy of its basis functions that can not take advantage of edges regularity and moreover, direction edge that is neither vertical or horizontal is represented using many of these wavelet basis functions which does mean that DWT does not provide a sparse representation for such discontinuities. Several representations have been proposed to overcome this lack. Some of them deal with more orientations while introducing redundancy (e.g. ridgelets, curvelets, contourlets) and their implementations are not trivial or require 2-D non separable filtering. We present two oriented lifting-based schemes using separable filtering, lead by edge extraction, and inspired from bandelets and curved wavelets. An image is decomposed into a quadtree according to the edge elements orientation. For each leaf, a wavelet transform is performed along the most regular orientation, and then along its orthogonal direction. Different adapted filters may be used for these two directions in order to achieve anisotropic filtering. Our method permits also a perfect reconstruction and a critical sampling.
Visual processing and the bodily self
The 'body schema' has traditionally been defined as a passively updated, proprioceptive representation of the body. However, recent work has suggested that body representations are more complex and flexible than previously thought. They may integrate current perceptual information from all sensory modalities, and can be extended to incorporate indirect representations of the body and functional portions of tools. In the present study, we investigate the source of a facilitatory effect of viewing the body on speeded visual discrimination reaction times. Participants responded to identical visual stimuli that varied only in their context: being presented on the participant's own body, on the experimenter's body, or in a neutral context. The stimuli were filmed and viewed in real-time on a projector screen. Careful controls for attention, biological saliency, and attribution confirmed that the facilitatory effect depends critically on participants attributing the context to a real body. An intermediate effect was observed when the stimuli were presented on another person's body, suggesting that the effect of viewing one's own body might represent a conjunction of an interpersonal body effect and an egocentric effect.
A number of recent behavioral studies have shown that emotional expressions are differently perceived depending on the race of a face, and that perception of race cues is influenced by emotional expressions. However, neural processes related to the perception of invariant cues that indicate the identity of a face (such as race) are often described to proceed independently of processes related to the perception of cues that can vary over time (such as emotion). Using a visual face adaptation paradigm, we tested whether these behavioral interactions between emotion and race also reflect interdependent neural representation of emotion and race. We compared visual emotion aftereffects when the adapting face and ambiguous test face differed in race or not. Emotion aftereffects were much smaller in different race (DR) trials than same race (SR) trials, indicating that the neural representation of a facial expression is significantly different depending on whether the emotional face is black or white. It thus seems that invariable cues such as race interact with variable face cues such as emotion not just at a response level, but also at the level of perception and neural representation. PMID:19810791
A number of recent behavioral studies have shown that emotional expressions are differently perceived depending on the race of a face, and that perception of race cues is influenced by emotional expressions. However, neural processes related to the perception of invariant cues that indicate the identity of a face (such as race) are often described to proceed independently of processes related to the perception of cues that can vary over time (such as emotion). Using a visual face adaptation paradigm, we tested whether these behavioral interactions between emotion and race also reflect interdependent neural representation of emotion and race. We compared visual emotion aftereffects when the adapting face and ambiguous test face differed in race or not. Emotion aftereffects were much smaller in different race (DR) trials than same race (SR) trials, indicating that the neural representation of a facial expression is significantly different depending on whether the emotional face is black or white. It thus seems that invariable cues such as race interact with variable face cues such as emotion not just at a response level, but also at the level of perception and neural representation. PMID:22403531
Understanding the levator ani complex architecture is of major clinical relevance. The aim of this study was to determine the feasibility of magnetic resonance (MR) fiber tractography with diffusion tensor imaging (DTI) as a tool for the three-dimensional (3D) representation of normal subdivisions of the levator ani. Ten young nulliparous female volunteers underwent DTI at 1.5 T MR imaging. Diffusion-weighted axial sequence of the pelvic floor was performed with additional T2-weighted multiplanar sequences for anatomical reference. Fiber tractography for visualization of each Terminologia Anatomica-listed major levator ani subdivision was performed. Numeric muscular fibers extracted after tractography were judged as accurate when localized within the boundaries of the muscle, and inaccurate when projecting out of the boundaries of the muscle. From the fiber tracking of each subdivision the number of numeric fibers (inaccurate and accurate) and a score (from 3 to 0) of the adequacy of the 3D representation were calculated. All but two volunteers completed the protocol. The mean number of accurate fibers was 17 ± 2 for the pubovisceralis, 14 ± 6 for the puborectalis and 1 ± 1 for the iliococcygeus. The quality of the 3D representation was judged as good (score = 2) for the pubovisceralis and puborectalis, and inaccurate (score = 0) for the iliococcygeus. Our study is the first step to a 3D visualization of the three major levator ani subdivisions, which could help to better understand their in vivo functional anatomy. PMID:22757638
Integrating human- and computer-based approaches to feature extraction and analysis
A major goal of imaging systems is to help doctors, scientists, engineers, and analysts identify patterns and features in complex data. There is a wide range of imaging, visualization, and graphics systems, ranging from fully automatic systems that extract features algorithmically to interactive systems that allow the analyst to manipulate visual representations directly to discover features. Although automatic feature-extraction algorithms are often directed by human observation, and human pattern recognition is often supported by algorithmic tools, very little work has been done to explore how to capitalize on the interaction between human and machine pattern recognition. This paper introduces a preliminary roadmap for guiding research in this space. One key concept is the explicit consideration of the task, which determines which methods and tools will be most effective. The second is the explicit inclusion of a "human-in-the-loop," who interacts with the data, the algorithms, and representations, to identify meaningful features. The third is the inclusion of a process for creating a mathematical representation of the features that have been "carved out" by the human analyst, for use in comparison, database query or analysis.
A body-part-specific impairment in the visual recognition of actions in chronic pain patients.
Most people suffer musculoskeletal pain sometime in their lives. Although the pain usually disappears with the healing, it may become chronic. Recent evidence suggests that high-level cortical representations play a role in chronic pain. Here we hypothesized that the sensorimotor representations of the affected body parts are specifically inhibited with chronic pain. Thus, if these representations are not accessible for the actions performed by one's own body, neither should they be for the perception of actions performed by others. Chronic pain patients are often focused on possibly painful movements, but visual processes are not affected by chronic pain, so we expected that patients should have no problems recognizing point-light biological motion displays, but should be unable to extract detailed somatosensory and motor information from such displays. Indeed, we found that patients had no difficulty perceiving point-light biological motion, and were not impaired in judging manipulated weight from movements they would be able to perform. However, patients with chronic shoulder pain were specifically impaired to judge the weight from observed manual transfer movements, whereas chronic low-back pain patients were specifically impaired for trunk-rotation movements. This result gives important new insights into chronic pain. Also, this new impairment of biological motion perception is unique in that it is unrelated to visual deficits. PMID:22609431
Don't Shoot the Messnger: Memory for Misspellings in Context
Misspellings in sentences are usually easy to understand by readers due to top-down influences. Although top-down processing allows for fluent reading of misspelled items, the nature of their representations in memory is not known. If representations of misspellings are distinct from representations of correctly spelled words, their influence should be seen in later recognition decisions. In this set of experiments, participants read words and misspellings embedded in sentences and were later given a recognition test. The sentences contained semantically biased or neutral contexts. In Experiment 1, misspellings were created by removing a single letter (e.g., "drveway"). In Experiment 2, the recognition items probes were presented in uppercase letters (e.g., "DRVEWAY") to reduce the visual similarity between study and test items. In Experiment 3, the misspellings were created by substituting visually similar letters (e.g., "driweway"). In contrast to the previous experiments, in Experiment 4, participants were explicitly told about the memory test to see how response strategies affect performance. Overall, the results indicate
