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Sample records for khuri representation

  1. Why Representations?

    ERIC Educational Resources Information Center

    Schultz, James E.; Waters, Michael S.

    2000-01-01

    Discusses representations in the context of solving a system of linear equations. Views representations (concrete, tables, graphs, algebraic, matrices) from perspectives of understanding, technology, generalization, exact versus approximate solution, and learning style. (KHR)

  2. Representation is representation of similarities.

    PubMed

    Edelman, S

    1998-08-01

    Advanced perceptual systems are faced with the problem of securing a principled (ideally, veridical) relationship between the world and its internal representation. I propose a unified approach to visual representation, addressing the need for superordinate and basic-level categorization and for the identification of specific instances of familiar categories. According to the proposed theory, a shape is represented internally by the responses of a small number of tuned modules, each broadly selective for some reference shape, whose similarity to the stimulus it measures. This amounts to embedding the stimulus in a low-dimensional proximal shape space spanned by the outputs of the active modules. This shape space supports representations of distal shape similarities that are veridical as Shepard's (1968) second-order isomorphisms (i.e., correspondence between distal and proximal similarities among shapes, rather than between distal shapes and their proximal representations). Representation in terms of similarities to reference shapes supports processing (e.g., discrimination) of shapes that are radically different from the reference ones, without the need for the computationally problematic decomposition into parts required by other theories. Furthermore, a general expression for similarity between two stimuli, based on comparisons to reference shapes, can be used to derive models of perceived similarity ranging from continuous, symmetric, and hierarchical ones, as in multidimensional scaling (Shepard 1980), to discrete and nonhierarchical ones, as in the general contrast models (Shepard & Arabie 1979; Tversky 1977). PMID:10097019

  3. Representing Representation

    ERIC Educational Resources Information Center

    Kuntz, Aaron M.

    2010-01-01

    What can be known and how to render what we know are perpetual quandaries met by qualitative research, complicated further by the understanding that the everyday discourses influencing our representations are often tacit, unspoken or heard so often that they seem to warrant little reflection. In this article, I offer analytic memos as a means for…

  4. Manipulating Representations.

    PubMed

    Recchia-Luciani, Angelo N M

    2012-04-01

    The present paper proposes a definition for the complex polysemic concepts of consciousness and awareness (in humans as well as in other species), and puts forward the idea of a progressive ontological development of consciousness from a state of 'childhood' awareness, in order to explain that humans are not only able to manipulate objects, but also their mental representations. The paper builds on the idea of qualia intended as entities posing regular invariant requests to neural processes, trough the permanence of different properties. The concept of semantic differential introduces the properties of metaphorical qualia as an exclusively human ability. Furthermore this paper proposes a classification of qualia, according to the models-with different levels of abstraction-they are implied in, in a taxonomic perspective. This, in turn, becomes a source of categorization of divergent representations, sign systems, and forms of intentionality, relying always on biological criteria. New emerging image-of-the-world-devices are proposed, whose qualia are likely to be only accessible to humans: emotional qualia, where emotion accounts for the invariant and dominant property; and the qualic self where continuity, combined with the oneness of the self, accounts for the invariant and dominant property. The concept of congruence between different domains in a metaphor introduces the possibility of a general evaluation of truth and falsity of all kinds of metaphorical constructs, while the work of Matte Blanco enables us to classify conscious versus unconscious metaphors, both in individuals and in social organizations. PMID:22347988

  5. Representation in Memory.

    ERIC Educational Resources Information Center

    Rumelhart, David E.; Norman, Donald A.

    This paper reviews work on the representation of knowledge from within psychology and artificial intelligence. The work covers the nature of representation, the distinction between the represented world and the representing world, and significant issues concerned with propositional, analogical, and superpositional representations. Specific topics…

  6. XML-BASED REPRESENTATION

    SciTech Connect

    R. KELSEY

    2001-02-01

    For focused applications with limited user and use application communities, XML can be the right choice for representation. It is easy to use, maintain, and extend and enjoys wide support in commercial and research sectors. When the knowledge and information to be represented is object-based and use of that knowledge and information is a high priority, then XML-based representation should be considered. This paper discusses some of the issues involved in using XML-based representation and presents an example application that successfully uses an XML-based representation.

  7. Inscriptions Becoming Representations in Representational Practices

    ERIC Educational Resources Information Center

    Medina, Richard; Suthers, Daniel

    2013-01-01

    We analyze the interaction of 3 students working on mathematics problems over several days in a virtual math team. Our analysis traces out how successful collaboration in a later session is contingent upon the work of prior sessions and shows how the development of representational practices is an important aspect of these participants' problem…

  8. Reading Visual Representations

    ERIC Educational Resources Information Center

    Rubenstein, Rheta N.; Thompson, Denisse R.

    2012-01-01

    Mathematics is rich in visual representations. Such visual representations are the means by which mathematical patterns "are recorded and analyzed." With respect to "vocabulary" and "symbols," numerous educators have focused on issues inherent in the language of mathematics that influence students' success with mathematics communication.…

  9. Contacts de langues et representations (Language Contacts and Representations).

    ERIC Educational Resources Information Center

    Matthey, Marinette, Ed.

    1997-01-01

    Essays on language contact and the image of language, entirely in French, include: "Representations 'du' contexte et representations 'en' contexte? Eleves et enseignants face a l'apprentissage de la langue" ("Representations 'of' Context or Representations 'in' Context? Students and Teachers Facing Language Learning" (Laurent Gajo); "Le crepuscule…

  10. Grassmannian sparse representations

    NASA Astrophysics Data System (ADS)

    Azary, Sherif; Savakis, Andreas

    2015-05-01

    We present Grassmannian sparse representations (GSR), a sparse representation Grassmann learning framework for efficient classification. Sparse representation classification offers a powerful approach for recognition in a variety of contexts. However, a major drawback of sparse representation methods is their computational performance and memory utilization for high-dimensional data. A Grassmann manifold is a space that promotes smooth surfaces where points represent subspaces and the relationship between points is defined by the mapping of an orthogonal matrix. Grassmann manifolds are well suited for computer vision problems because they promote high between-class discrimination and within-class clustering, while offering computational advantages by mapping each subspace onto a single point. The GSR framework combines Grassmannian kernels and sparse representations, including regularized least squares and least angle regression, to improve high accuracy recognition while overcoming the drawbacks of performance and dependencies on high dimensional data distributions. The effectiveness of GSR is demonstrated on computationally intensive multiview action sequences, three-dimensional action sequences, and face recognition datasets.

  11. Spacecraft Attitude Representations

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis

    1999-01-01

    The direction cosine matrix or attitude matrix is the most fundamental representation of the attitude, but it is very inefficient: It has six redundant parameters, it is difficult to enforce the six (orthogonality) constraints. the four-component quaternion representation is very convenient: it has only one redundant parameter, it is easy to enforce the normalization constraint, the attitude matrix is a homogeneous quadratic function of q, quaternion kinematics are bilinear in q and m. Euler angles are extensively used: they often have a physical interpretation, they provide a natural description of some spacecraft motions (COBE, MAP), but kinematics and attitude matrix involve trigonometric functions, "gimbal lock" for certain values of the angles. Other minimum (three-parameter) representations: Gibbs vector is infinite for 180 deg rotations, but useful for analysis, Modified Rodrigues Parameters are nonsingular, no trig functions, Rotation vector phi is nonsingular, but requires trig functions.

  12. Umbra's system representation.

    SciTech Connect

    McDonald, Michael James

    2005-07-01

    This document describes the Umbra System representation. Umbra System representation, initially developed in the spring of 2003, is implemented in Incr/Tcl using concepts borrowed from Carnegie Mellon University's Architecture Description Language (ADL) called Acme. In the spring of 2004 through January 2005, System was converted to Umbra 4, extended slightly, and adopted as the underlying software system for a variety of Umbra applications that support Complex Systems Engineering (CSE) and Complex Adaptive Systems Engineering (CASE). System is now a standard part Of Umbra 4. While Umbra 4 also includes an XML parser for System, the XML parser and Schema are not described in this document.

  13. Reading Students' Representations

    ERIC Educational Resources Information Center

    Diezmann, Carmel M.; McCosker, Natalie T.

    2011-01-01

    Representations play a key role in mathematical thinking: They offer "a medium" to express mathematical knowledge or organize mathematical information and to discern mathematical relationships (e.g., relative household expenditures on a pie chart) using text, symbols, or graphics. They also furnish "tools" for mathematical processes (e.g., use of…

  14. The Problem of Representation

    ERIC Educational Resources Information Center

    Tervo, Juuso

    2012-01-01

    In "Postphysical Vision: Art Education's Challenge in an Age of Globalized Aesthetics (AMondofesto)" (2008) and "Beyond Aesthetics: Returning Force and Truth to Art and Its Education" (2009), jan jagodzinski argued for politics that go "beyond" representation--a project that radically questions visual culture…

  15. [Time perceptions and representations].

    PubMed

    Tordjman, S

    2015-09-01

    Representations of time and time measurements depend on subjective constructs that vary according to changes in our concepts, beliefs, societal needs and technical advances. Similarly, the past, the future and the present are subjective representations that depend on each individual's psychic time and biological time. Therefore, there is no single, one-size-fits-all time for everyone, but rather a different, subjective time for each individual. We need to acknowledge the existence of different inter-individual times but also intra-individual times, to which different functions and different rhythms are attached, depending on the system of reference. However, the construction of these time perceptions and representations is influenced by objective factors (physiological, physical and cognitive) related to neuroscience which will be presented and discussed in this article. Thus, studying representation and perception of time lies at the crossroads between neuroscience, human sciences and philosophy. Furthermore, it is possible to identify several constants among the many and various representations of time and their corresponding measures, regardless of the system of time reference. These include the notion of movements repeated in a stable rhythmic pattern involving the recurrence of the same interval of time, which enables us to define units of time of equal and invariable duration. This rhythmicity is also found at a physiological level and contributes through circadian rhythms, in particular the melatonin rhythm, to the existence of a biological time. Alterations of temporality in mental disorders will be also discussed in this article illustrated by certain developmental disorders such as autism spectrum disorders. In particular, the hypothesis will be developed that children with autism would need to create discontinuity out of continuity through stereotyped behaviors and/or interests. This discontinuity repeated at regular intervals could have been

  16. The Functions of Multiple Representations.

    ERIC Educational Resources Information Center

    Ainsworth, Shaaron

    1999-01-01

    Discusses multiple representations and multimedia learning environments; describes a functional taxonomy of MERs (multiple external representations); and considers how MERs are used to support cognitive processes in learning and problem solving with computers. (Contains 41 references.) (Author/LRW)

  17. Standard model of knowledge representation

    NASA Astrophysics Data System (ADS)

    Yin, Wensheng

    2016-03-01

    Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

  18. Representation in incremental learning

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Work focused on two areas in machine learning: representation for inductive learning and how to apply concept learning techniques to learning state preferences, which can represent search control knowledge for problem solving. Specifically, in the first area the issues of the effect of representation on learning, on how learning formalisms are biased, and how concept learning can benefit from the use of a hybrid formalism are addressed. In the second area, the issues of developing an agent to learn search control knowledge from the relative values of states, of the source of that qualitative information, and of the ability to use both quantitative and qualitative information in order to develop an effective problem-solving policy are examined.

  19. Naturalising Representational Content

    PubMed Central

    Shea, Nicholas

    2014-01-01

    This paper sets out a view about the explanatory role of representational content and advocates one approach to naturalising content – to giving a naturalistic account of what makes an entity a representation and in virtue of what it has the content it does. It argues for pluralism about the metaphysics of content and suggests that a good strategy is to ask the content question with respect to a variety of predictively successful information processing models in experimental psychology and cognitive neuroscience; and hence that data from psychology and cognitive neuroscience should play a greater role in theorising about the nature of content. Finally, the contours of the view are illustrated by drawing out and defending a surprising consequence: that individuation of vehicles of content is partly externalist. PMID:24563661

  20. Gabor representation with oversampling

    NASA Astrophysics Data System (ADS)

    Zibulski, Meir; Zeevi, Yehoshua Y.

    1992-11-01

    An approach for characterizing the properties of the basis functions of the Gabor representation in the context of oversampling is presented. The approach is based on the concept of frames and utilizes the Piecewise Zak Transform (PZT). The frame operator associated with the Gabor-type frame, the so-called Weyl-Heisenberg frame, is examined for a rational oversampling rate by representing the frame operator as a matrix-valued function in the PZT domain. Completeness and frame properties of the Gabor representation functions are examined in relation to the properties of the matrix-valued function. The frame bounds are calculated by means of the eigenvalues of the matrix-valued function, and the dual-frame, which is used in calculation of the expansion coefficients, is expressed by means of the inverse matrix.

  1. Naturalising Representational Content.

    PubMed

    Shea, Nicholas

    2013-05-01

    This paper sets out a view about the explanatory role of representational content and advocates one approach to naturalising content - to giving a naturalistic account of what makes an entity a representation and in virtue of what it has the content it does. It argues for pluralism about the metaphysics of content and suggests that a good strategy is to ask the content question with respect to a variety of predictively successful information processing models in experimental psychology and cognitive neuroscience; and hence that data from psychology and cognitive neuroscience should play a greater role in theorising about the nature of content. Finally, the contours of the view are illustrated by drawing out and defending a surprising consequence: that individuation of vehicles of content is partly externalist. PMID:24563661

  2. Supramodal representation of emotions.

    PubMed

    Klasen, Martin; Kenworthy, Charles A; Mathiak, Krystyna A; Kircher, Tilo T J; Mathiak, Klaus

    2011-09-21

    Supramodal representation of emotion and its neural substrates have recently attracted attention as a marker of social cognition. However, the question whether perceptual integration of facial and vocal emotions takes place in primary sensory areas, multimodal cortices, or in affective structures remains unanswered yet. Using novel computer-generated stimuli, we combined emotional faces and voices in congruent and incongruent ways and assessed functional brain data (fMRI) during an emotional classification task. Both congruent and incongruent audiovisual stimuli evoked larger responses in thalamus and superior temporal regions compared with unimodal conditions. Congruent emotions were characterized by activation in amygdala, insula, ventral posterior cingulate (vPCC), temporo-occipital, and auditory cortices; incongruent emotions activated a frontoparietal network and bilateral caudate nucleus, indicating a greater processing load in working memory and emotion-encoding areas. The vPCC alone exhibited differential reactions to congruency and incongruency for all emotion categories and can thus be considered a central structure for supramodal representation of complex emotional information. Moreover, the left amygdala reflected supramodal representation of happy stimuli. These findings document that emotional information does not merge at the perceptual audiovisual integration level in unimodal or multimodal areas, but in vPCC and amygdala. PMID:21940454

  3. Spatial representation of soundscape

    NASA Astrophysics Data System (ADS)

    Boubezari, Mohammed; Bento Coelho, Jos-Luis

    2001-05-01

    For the last 30 years the concept of soundscape has been largely adopted in many scientific disciplines and by the urban experts for the benefit of a better comprehension and management of the sound environment. However, the spatial representation of the soundscape as a simple tool for the description, management or composition of sound environment is always needed. In this article a method is presented for the spatial sound representation with differentiated sources. The first results are shown. This method gives an account of the soundscape as close as possible to the way it can be perceived by the listener in each location. This method generates qualitative sound maps in a reduced urban scale, based on in situ measurements and on the implication of the measuring subject perception. The maps are sufficient enough to isolate many sound sources of the overall sound field. In this manner, sound quality refers to the sound attribute of a perceived object. It is neither an aesthetic judgment nor traditional psychoacoustics criteria. Concrete examples of application to squares in the city of Lisbon will be shown and discussed. The limits and the prospects of such a qualitative representation will also be presented and discussed.

  4. Mental Representations of Weekdays

    PubMed Central

    Ellis, David A.; Wiseman, Richard; Jenkins, Rob

    2015-01-01

    Keeping social appointments involves keeping track of what day it is. In practice, mismatches between apparent day and actual day are common. For example, a person might think the current day is Wednesday when in fact it is Thursday. Here we show that such mismatches are highly systematic, and can be traced to specific properties of their mental representations. In Study 1, mismatches between apparent day and actual day occurred more frequently on midweek days (Tuesday, Wednesday, and Thursday) than on other days, and were mainly due to intrusions from immediately neighboring days. In Study 2, reaction times to report the current day were fastest on Monday and Friday, and slowest midweek. In Study 3, participants generated fewer semantic associations for “Tuesday”, “Wednesday” and “Thursday” than for other weekday names. Similarly, Google searches found fewer occurrences of midweek days in webpages and books. Analysis of affective norms revealed that participants’ associations were strongly negative for Monday, strongly positive for Friday, and graded over the intervening days. Midweek days are confusable because their mental representations are sparse and similar. Mondays and Fridays are less confusable because their mental representations are rich and distinctive, forming two extremes along a continuum of change. PMID:26288194

  5. Translation between representation languages

    NASA Technical Reports Server (NTRS)

    Vanbaalen, Jeffrey

    1994-01-01

    A capability for translating between representation languages is critical for effective knowledge base reuse. A translation technology for knowledge representation languages based on the use of an interlingua for communicating knowledge is described. The interlingua-based translation process consists of three major steps: translation from the source language into a subset of the interlingua, translation between subsets of the interlingua, and translation from a subset of the interlingua into the target language. The first translation step into the interlingua can typically be specified in the form of a grammar that describes how each top-level form in the source language translates into the interlingua. In cases where the source language does not have a declarative semantics, such a grammar is also a specification of a declarative semantics for the language. A methodology for building translators that is currently under development is described. A 'translator shell' based on this methodology is also under development. The shell has been used to build translators for multiple representation languages and those translators have successfully translated nontrivial knowledge bases.

  6. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1990-02-19

    The central research problem of this project is the effective representation, computation, and display of surfaces interpolating to information in three or more dimensions. If the given information is located on another surface, then the problem is to construct a surface defined on a surface''. Sometimes properties of an already defined surface are desired, which is geometry processing''. Visualization of multivariate surfaces is possible by means of contouring higher dimensional surfaces. These problems and more are discussed below. The broad sweep from constructive mathematics through computational algorithms to computer graphics illustrations is utilized in this research. The breadth and depth of this research activity makes this research project unique.

  7. Sparse representation with kernels.

    PubMed

    Gao, Shenghua; Tsang, Ivor Wai-Hung; Chia, Liang-Tien

    2013-02-01

    Recent research has shown the initial success of sparse coding (Sc) in solving many computer vision tasks. Motivated by the fact that kernel trick can capture the nonlinear similarity of features, which helps in finding a sparse representation of nonlinear features, we propose kernel sparse representation (KSR). Essentially, KSR is a sparse coding technique in a high dimensional feature space mapped by an implicit mapping function. We apply KSR to feature coding in image classification, face recognition, and kernel matrix approximation. More specifically, by incorporating KSR into spatial pyramid matching (SPM), we develop KSRSPM, which achieves a good performance for image classification. Moreover, KSR-based feature coding can be shown as a generalization of efficient match kernel and an extension of Sc-based SPM. We further show that our proposed KSR using a histogram intersection kernel (HIK) can be considered a soft assignment extension of HIK-based feature quantization in the feature coding process. Besides feature coding, comparing with sparse coding, KSR can learn more discriminative sparse codes and achieve higher accuracy for face recognition. Moreover, KSR can also be applied to kernel matrix approximation in large scale learning tasks, and it demonstrates its robustness to kernel matrix approximation, especially when a small fraction of the data is used. Extensive experimental results demonstrate promising results of KSR in image classification, face recognition, and kernel matrix approximation. All these applications prove the effectiveness of KSR in computer vision and machine learning tasks. PMID:23014744

  8. Geographic representation in spatial analysis

    NASA Astrophysics Data System (ADS)

    Miller, Harvey J.

    Spatial analysis mostly developed in an era when data was scarce and computational power was expensive. Consequently, traditional spatial analysis greatly simplifies its representations of geography. The rise of geographic information science (GISci) and the changing nature of scientific questions at the end of the 20th century suggest a comprehensive re-examination of geographic representation in spatial analysis. This paper reviews the potential for improved representations of geography in spatial analysis. Existing tools in spatial analysis and new tools available from GISci have tremendous potential for bringing more sophisticated representations of geography to the forefront of spatial analysis theory and application.

  9. Resource representation in COMPASS

    NASA Technical Reports Server (NTRS)

    Fox, Barry R.

    1991-01-01

    A set of viewgraphs on resource representation in COMPASS is given. COMPASS is an incremental, interactive, non-chronological scheduler written in Ada with an X-windows user interface. Beginning with an empty schedule, activities are added to the schedule one at a time, taking into consideration the placement of the activities already on the timeline and the resources that have been reserved for them. The order that the activities are added to the timeline and their location on the timeline are controlled by selection and placement commands invoked by the user. The order that activities are added to the timeline and their location are independent. The COMPASS code library is a cost effective platform for the development of new scheduling applications. It can be effectively used off the shelf for compatible scheduling applications or it can be used as a parts library for the development of custom scheduling systems.

  10. Parental representations of transsexuals.

    PubMed

    Parker, G; Barr, R

    1982-06-01

    The parental representations of 30 male-to-female transsexuals were rated using a measure of fundamental parental dimensions and shown to be of acceptable validity as a measure both of perceived and actual parental characteristics. Scores on that measure were compared separately against scores returned by matched male and female controls. The transsexuals did not differ from the male controls in their scoring of their mothers but did score their fathers as less caring and more overprotective. These differences were weaker for the comparisons made against the female controls. Item analyses suggested that the greater paternal "overprotection" experienced by transsexuals was due to their fathers being perceived as offering less encouragement to their sons' independence and autonomy. Several interpretations of the findings are considered. PMID:7138296

  11. Intentionality, Representation, and Anticipation

    NASA Astrophysics Data System (ADS)

    De Preester, Helena

    2002-09-01

    Both Brentano and Merleau-Ponty have developed an account of intentionality, which nevertheless differ profoundly in the following respect. According to Brentano, intentionality mainly is a matter of mental presentations. This marks the beginning of phenomenology's difficult relation with the nature of the intentional reference. Merleau-Ponty, on the other hand, has situated intentionality on the level of the body, a turn which has important implications for the nature of intentionality. Intentionality no longer is primarily based on having (re)presentations, but is rooted in the dynamics of the living body. To contrast those approaches enables us to make clear in what way intentionality is studied nowadays. On the one hand, intentionality is conceived of as a matter of formal-syntactical causality in cognitive science, and in particular in classical-computational theory. On the other hand, a interactivist approach offers a more Merleau-Ponty-like point of view, in which autonomy, embodiment and interaction are stressed.

  12. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1991-04-02

    Modern computing resources permit the generation of large amounts of numerical data. These large data sets, if left in numerical form, can be overwhelming. Such large data sets are usually discrete points from some underlying physical phenomenon. Because we need to evaluate the phenomenon at places where we don't have data, a continuous representation (a surface'') is required. A simple example is a weather map obtained from a discrete set of weather stations. (For more examples including multi-dimensional ones, see the article by Dr. Rosemary Chang in the enclosed IRIS Universe). In order to create a scientific structure encompassing the data, we construct an interpolating mathematical surface which can evaluate at arbitrary locations. We can also display and analyze the results via interactive computer graphics. In our research we construct a very wide variety of surfaces for applied geometry problems that have sound theoretical foundations. However, our surfaces have the distinguishing feature that they are constructed to solve short or long term practical problems. This DOE-funded project has developed the premiere research team in the subject of constructing surfaces (3D and higher dimensional) that provide smooth representations of real scientific and engineering information, including state of the art computer graphics visualizations. However, our main contribution is in the development of fundamental constructive mathematical methods and visualization techniques which can be incorporated into a wide variety of applications. This project combines constructive mathematics, algorithms, and computer graphics, all applied to real problems. The project is a unique resource, considered by our peers to be a de facto national center for this type of research.

  13. Age Differences in Symbolic Representation: Fluidity in Representational Construction.

    ERIC Educational Resources Information Center

    Reifel, Stuart

    This paper reports a cross-sectional, developmental study of the fluidity of children's mental functioning (representational skills) in contexts involving the representational use of blocks. Data were collected from a sample of 40 children from a laboratory school: 20 four-year-olds and 20 seven-year-olds, with an equal number of boys and girls in…

  14. Knowledge Representation: A Brief Review.

    ERIC Educational Resources Information Center

    Vickery, B. C.

    1986-01-01

    Reviews different structures and techniques of knowledge representation: structure of database records and files, data structures in computer programming, syntatic and semantic structure of natural language, knowledge representation in artificial intelligence, and models of human memory. A prototype expert system that makes use of some of these…

  15. A Philosophical Discussion of Representation.

    ERIC Educational Resources Information Center

    Moriarty, Sandra E.; Kenney, Keith

    One of the most basic theoretical areas in the study of visual communication and visual literacy is the nature of representation. Some of the important research in this area is reviewed in this paper, and a model of representation is developed that satisfies many of the philosophical concerns. The paper begins with a discussion on the relationship…

  16. Symbolic Representation of Probabilistic Worlds

    ERIC Educational Resources Information Center

    Feldman, Jacob

    2012-01-01

    Symbolic representation of environmental variables is a ubiquitous and often debated component of cognitive science. Yet notwithstanding centuries of philosophical discussion, the efficacy, scope, and validity of such representation has rarely been given direct consideration from a mathematical point of view. This paper introduces a quantitative…

  17. The Representational Value of Hats

    ERIC Educational Resources Information Center

    Watson, Jane M.; Fitzallen, Noleine E.; Wilson, Karen G.; Creed, Julie F.

    2008-01-01

    The literature that is available on the topic of representations in mathematics is vast. One commonly discussed item is graphical representations. From the history of mathematics to modern uses of technology, a variety of graphical forms are available for middle school students to use to represent mathematical ideas. The ideas range from algebraic…

  18. Revealing children's implicit spelling representations.

    PubMed

    Critten, Sarah; Pine, Karen J; Messer, David J

    2013-06-01

    Conceptualizing the underlying representations and cognitive mechanisms of children's spelling development is a key challenge for literacy researchers. Using the Representational Redescription model (Karmiloff-Smith), Critten, Pine and Steffler (2007) demonstrated that the acquisition of phonological and morphological knowledge may be underpinned by increasingly explicit levels of spelling representation. However, their proposal that implicit representations may underlie early 'visually based' spelling remains unresolved. Children (N = 101, aged 4-6 years) were given a recognition task (Critten et al., 2007) and a novel production task, both involving verbal justifications of why spellings are correct/incorrect, strategy use and word pattern similarity. Results for both tasks supported an implicit level of spelling characterized by the ability to correctly recognize/produce words but the inability to explain operational strategies or generalize knowledge. Explicit levels and multiple representations were also in evidence across the two tasks. Implications for cognitive mechanisms underlying spelling development are discussed. PMID:23659891

  19. A generalized wavelet extrema representation

    SciTech Connect

    Lu, Jian; Lades, M.

    1995-10-01

    The wavelet extrema representation originated by Stephane Mallat is a unique framework for low-level and intermediate-level (feature) processing. In this paper, we present a new form of wavelet extrema representation generalizing Mallat`s original work. The generalized wavelet extrema representation is a feature-based multiscale representation. For a particular choice of wavelet, our scheme can be interpreted as representing a signal or image by its edges, and peaks and valleys at multiple scales. Such a representation is shown to be stable -- the original signal or image can be reconstructed with very good quality. It is further shown that a signal or image can be modeled as piecewise monotonic, with all turning points between monotonic segments given by the wavelet extrema. A new projection operator is introduced to enforce piecewise inonotonicity of a signal in its reconstruction. This leads to an enhancement to previously developed algorithms in preventing artifacts in reconstructed signal.

  20. Stable face representations

    PubMed Central

    Jenkins, Rob; Burton, A. Mike

    2011-01-01

    Photographs are often used to establish the identity of an individual or to verify that they are who they claim to be. Yet, recent research shows that it is surprisingly difficult to match a photo to a face. Neither humans nor machines can perform this task reliably. Although human perceivers are good at matching familiar faces, performance with unfamiliar faces is strikingly poor. The situation is no better for automatic face recognition systems. In practical settings, automatic systems have been consistently disappointing. In this review, we suggest that failure to distinguish between familiar and unfamiliar face processing has led to unrealistic expectations about face identification in applied settings. We also argue that a photograph is not necessarily a reliable indicator of facial appearance, and develop our proposal that summary statistics can provide more stable face representations. In particular, we show that image averaging stabilizes facial appearance by diluting aspects of the image that vary between snapshots of the same person. We review evidence that the resulting images can outperform photographs in both behavioural experiments and computer simulations, and outline promising directions for future research. PMID:21536553

  1. Archival Representation in the Digital Age

    ERIC Educational Resources Information Center

    Zhang, Jane

    2012-01-01

    This study analyzes the representation systems of three digitized archival collections using the traditional archival representation framework of provenance, order, and content. The results of the study reveal a prominent role of provenance representation, a compromised role of order representation, and an active role of content representation in…

  2. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1989-02-09

    The central research problem of this project is the effective representation and display of surfaces, interpolating to given information, in three or more dimensions. In a typical problem, we wish to create a surface from some discrete information. If this information is itself on another surface, the problem is to determine a surface defined on a surface,'' which is discussed below. Often, properties of an already constructed surface are desired: such geometry processing'' is described below. The Summary of Proposed Research from our original proposal describes the aims of this research project. This Summary and the Table of Contents from the original proposal are enclosed as an Appendix to this Progress Report. The broad sweep from constructive mathematics through algorithms and computer graphics displays is utilized in the research. The wide range of activity, directed in both theory and applications, makes this project unique. Last month in the first Ardent Titan delivered in the State of Arizona came to our group, funded by the DOE and Arizona State University. Although the Titan is a commercial product, its newness requires our close collaboration with Ardent to maximize results. During the past year, four faculty members and several graduate research assistants have worked on this DOE project. The gaining of new professionals is an important aspect of this project. A listing of the students and their topics is given in the Appendix. The most significant publication during the past year is the book, Curves and Surfaces for Computer Aided Geometric Design, by Dr. Gerald Farin. This 300 page volume helps fill a considerable gap in the subject and includes many new results on Bernstein-Bezier curves and surfaces.

  3. Representations of mechanical assembly sequences

    NASA Astrophysics Data System (ADS)

    Homem de Mello, Luiz S.; Sanderson, Arthur C.

    1991-04-01

    Five types of representations for assembly sequences are reviewed: the directed graph of feasible assembly sequences, the AND/OR graph of feasible assembly sequences, the set of establishment conditions, and two types of sets of precedence relationships. (precedence relationships between the establishment of one connection between parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process). The mappings of one representation into the others are established. The correctness and completeness of these representations are established. The results presented are needed in the proof of correctness and completeness of algorithms for the generation of mechanical assembly sequences.

  4. Attitude Representations for Kalman Filtering

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The four-component quaternion has the lowest dimensionality possible for a globally nonsingular attitude representation, it represents the attitude matrix as a homogeneous quadratic function, and its dynamic propagation equation is bilinear in the quaternion and the angular velocity. The quaternion is required to obey a unit norm constraint, though, so Kalman filters often employ a quaternion for the global attitude estimate and a three-component representation for small errors about the estimate. We consider these mixed attitude representations for both a first-order Extended Kalman filter and a second-order filter, as well for quaternion-norm-preserving attitude propagation.

  5. Representations of mechanical assembly sequences

    NASA Technical Reports Server (NTRS)

    Homem De Mello, Luiz S.; Sanderson, Arthur C.

    1991-01-01

    Five types of representations for assembly sequences are reviewed: the directed graph of feasible assembly sequences, the AND/OR graph of feasible assembly sequences, the set of establishment conditions, and two types of sets of precedence relationships. (precedence relationships between the establishment of one connection between parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process). The mappings of one representation into the others are established. The correctness and completeness of these representations are established. The results presented are needed in the proof of correctness and completeness of algorithms for the generation of mechanical assembly sequences.

  6. Computer representation of molecular surfaces

    SciTech Connect

    Max, N.L.

    1981-07-06

    This review article surveys recent work on computer representation of molecular surfaces. Several different algorithms are discussed for producing vector or raster drawings of space-filling models formed as the union of spheres. Other smoother surfaces are also considered.

  7. Vietnamese Document Representation and Classification

    NASA Astrophysics Data System (ADS)

    Nguyen, Giang-Son; Gao, Xiaoying; Andreae, Peter

    Vietnamese is very different from English and little research has been done on Vietnamese document classification, or indeed, on any kind of Vietnamese language processing, and only a few small corpora are available for research. We created a large Vietnamese text corpus with about 18000 documents, and manually classified them based on different criteria such as topics and styles, giving several classification tasks of different difficulty levels. This paper introduces a new syllable-based document representation at the morphological level of the language for efficient classification. We tested the representation on our corpus with different classification tasks using six classification algorithms and two feature selection techniques. Our experiments show that the new representation is effective for Vietnamese categorization, and suggest that best performance can be achieved using syllable-pair document representation, an SVM with a polynomial kernel as the learning algorithm, and using Information gain and an external dictionary for feature selection.

  8. Texture Representations Using Subspace Embeddings

    PubMed Central

    Yang, Xiaodong; Tian, YingLi

    2013-01-01

    In this paper, we propose a texture representation framework to map local texture patches into a low-dimensional texture subspace. In natural texture images, textons are entangled with multiple factors, such as rotation, scaling, viewpoint variation, illumination change, and non-rigid surface deformation. Mapping local texture patches into a low-dimensional subspace can alleviate or eliminate these undesired variation factors resulting from both geometric and photometric transformations. We observe that texture representations based on subspace embeddings have strong resistance to image deformations, meanwhile, are more distinctive and more compact than traditional representations. We investigate both linear and non-linear embedding methods including Principle Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Locality Preserving Projections (LPP) to compute the essential texture subspace. The experiments in the context of texture classification on benchmark datasets demonstrate that the proposed subspace embedding representations achieve the state-of-the-art results while with much fewer feature dimensions. PMID:23710105

  9. Texture Representations Using Subspace Embeddings.

    PubMed

    Yang, Xiaodong; Tian, Yingli

    2013-07-15

    In this paper, we propose a texture representation framework to map local texture patches into a low-dimensional texture subspace. In natural texture images, textons are entangled with multiple factors, such as rotation, scaling, viewpoint variation, illumination change, and non-rigid surface deformation. Mapping local texture patches into a low-dimensional subspace can alleviate or eliminate these undesired variation factors resulting from both geometric and photometric transformations. We observe that texture representations based on subspace embeddings have strong resistance to image deformations, meanwhile, are more distinctive and more compact than traditional representations. We investigate both linear and non-linear embedding methods including Principle Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Locality Preserving Projections (LPP) to compute the essential texture subspace. The experiments in the context of texture classification on benchmark datasets demonstrate that the proposed subspace embedding representations achieve the state-of-the-art results while with much fewer feature dimensions. PMID:23710105

  10. World representations for unmanned vehicles

    NASA Astrophysics Data System (ADS)

    Broten, Gregory S.; Monckton, Simon P.; Mackay, David; Collier, Jack

    2007-04-01

    Unmanned vehicles (UxV) operate in numerous environments, with air, ground and marine representing the majority of the implementations. All unmanned vehicles, when traversing unknown space, have similar requirements. They must sense their environment, create a world representation, and, then plan a path that safely avoids obstacles and hazards. Traditionally, each unmanned vehicle class used environment specific assumptions to create a unique world representation that was tailored to it operating environment. Thus, an unmanned aerial vehicle (UAV) used the simplest possible world representation, where all space above the ground plane was free of obstacles. Conversely, an unmanned ground vehicle (UGV) required a world representation that was suitable to its complex and unstructured environment. Such a clear cut differentiation between UAV and UGV environments is no longer valid as UAVs have migrated down to elevations where terrestrial structures are located. Thus, the operating environment for a low flying UAV contains similarities to the environments experienced by UGVs. As a result, the world representation techniques and algorithms developed for UGVs are now applicable to UAVs, since low flying UAVs must sense and represent its world in order to avoid obstacles. Defence R&D Canada (DRDC) conducts research and development in both the UGV and UAV fields. Researchers have developed a platform neutral world representation, based upon a uniform 21/ II-D elevation grid, that is applicable to many UxV classes, including aerial and ground vehicles. This paper describes DRDC's generic world representation, known as the Global Terrain map, and provides an example of unmanned ground vehicle implementation, along with details of it applicability to aerial vehicles.

  11. Data Representations for Geographic Information Systems.

    ERIC Educational Resources Information Center

    Shaffer, Clifford A.

    1992-01-01

    Surveys the field and literature of geographic information systems (GIS) and spatial data representation as it relates to GIS. Highlights include GIS terms, data types, and operations; vector representations and raster, or grid, representations; spatial indexing; elevation data representations; large spatial databases; and problem areas and future…

  12. Relativity of representations in quantum mechanics

    NASA Astrophysics Data System (ADS)

    de la Torre, A. C.

    2002-03-01

    Only the position representation is used in introductory quantum mechanics and the momentum representation is not usually presented until advanced undergraduate courses. To emphasize the relativity of the representations of the abstract formulation of quantum mechanics, two examples of representations related to the operators αX+(1-α)P and 1/2(XP+PX) are presented.

  13. Culture as shared cognitive representations.

    PubMed Central

    Romney, A K; Boyd, J P; Moore, C C; Batchelder, W H; Brazill, T J

    1996-01-01

    Culture consists of shared cognitive representations in the minds of individuals. This paper investigates the extent to which English speakers share the "same" semantic structure of English kinship terms. The semantic structure is defined as the arrangement of the terms relative to each other as represented in a metric space in which items judged more similar are placed closer to each other than items judged as less similar. The cognitive representation of the semantic structure, residing in the mind of an individual, is measured by judged similarity tasks involving comparisons among terms. Using six independent measurements, from each of 122 individuals, correspondence analysis represents the data in a common multidimensional spatial representation. Judged by a variety of statistical procedures, the individuals in our sample share virtually identical cognitive representations of the semantic structure of kinship terms. This model of culture accounts for 70-90% of the total variability in these data. We argue that our findings on kinship should generalize to all semantic domains--e.g., animals, emotions, etc. The investigation of semantic domains is important because they may reside in localized functional units in the brain, because they relate to a variety of cognitive processes, and because they have the potential to provide methods for diagnosing individual breakdowns in the structure of cognitive representations typical of such ailments as Alzheimer disease. PMID:11607678

  14. Active maintenance of semantic representations.

    PubMed

    Nishiyama, Ryoji

    2014-12-01

    In research on verbal working memory, articulatory rehearsal, a maintenance mechanism for phonological representations, has undergone intensive and excellent study. Possible mechanisms for semantic representation have received less attention. However, several studies have reported a double dissociation in types of memory deficits (semantic memory difficulties vs. phonological memory difficulties). This suggests the separability of two maintenance mechanisms. The present study focused on this separability in individuals with normal memory abilities, using a dual-task interference paradigm. The results indicate a crossover interaction between memory and interference task effects: Preventing articulatory rehearsal more strongly disrupted the phonological memory task, whereas performing a tapping task that interfered with attentional control more strongly disrupted semantic memory. These results suggest that semantic representations are actively maintained by a mechanism other than phonological maintenance. PMID:24687734

  15. Representation of Ideal Magnetohydrodynamic Modes

    SciTech Connect

    Roscoe B. White

    2013-01-15

    One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through δ Β = ∇ X (xi X B) ensures that δ B • ∇ ψ = 0 at a resonance, with ψ labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation δ Β = ∇ X αB. These two representations are equivalent, but the vanishing of δ B • ∇ψ at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in xi to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed

  16. Assessing value representation in animals.

    PubMed

    San-Galli, Aurore; Bouret, Sebastien

    2015-01-01

    Among all factors modulating our motivation to perform a given action, the ability to represent its outcome is clearly the most determining. Representation of outcomes, rewards in particular, and how they guide behavior, have sparked much research. Both practically and theoretically, understanding the relationship between the representation of outcome value and the organization of goal directed behavior implies that these two processes can be assessed independently. Most of animal studies essentially used instrumental actions as a proxy for the expected goal-value. The purpose of this article is to consider alternative measures of expected outcome value in animals, which are critical to understand the behavioral and neurobiological mechanisms relating the representation of the expected outcome to the organization of the behavior oriented towards its obtention. This would be critical in the field of decision making or social interactions, where the value of multiple items must often be compared and/or shared among individuals to determine the course of actions. PMID:25092260

  17. Social representations of female orgasm.

    PubMed

    Lavie-Ajayi, Maya; Joffe, Hélène

    2009-01-01

    This study examines women's social representations of female orgasm. Fifty semi-structured interviews were conducted with British women. The data were thematically analysed and compared with the content of female orgasm-related writing in two women's magazines over a 30-year period. The results indicate that orgasm is deemed the goal of sex with emphasis on its physiological dimension. However, the women and the magazines graft onto this scientifically driven representation the importance of relational and emotive aspects of orgasm. For the women, particularly those who experience themselves as having problems with orgasm, the scientifically driven representations induce feelings of failure, but are also resisted. The findings highlight the role played by the social context in women's subjective experience of their sexual health. PMID:19129342

  18. Interferometric seismoelectric Green's function representations

    NASA Astrophysics Data System (ADS)

    de Ridder, Sjoerd A. L.; Slob, Evert; Wapenaar, Kees

    2009-09-01

    Interferometric Green's function representations can be used to retrieve a Green's function between two receiver stations, effectively turning one receiver into a source. Through reciprocity theorems of the convolution and correlation types, we derive interferometric Green's function representations for coupled electromagnetic and seismic wave propagation in 1-D. These representations express a symmetrized Green's function in terms of correlations of sources distributed throughout the domain of reciprocity and on its boundary. The main challenge for practical implementation is the necessity of sources throughout a domain. Numerical examples show how this constraint can be relaxed for different configurations. In a configuration of two layers bounded by a vacuum, seismic noise sources behind the interface can be used to recover seismoelectric reflection responses that suffer from small amplitude losses, but are not corrupted by spurious events.

  19. Learning multiple layers of representation.

    PubMed

    Hinton, Geoffrey E

    2007-10-01

    To achieve its impressive performance in tasks such as speech perception or object recognition, the brain extracts multiple levels of representation from the sensory input. Backpropagation was the first computationally efficient model of how neural networks could learn multiple layers of representation, but it required labeled training data and it did not work well in deep networks. The limitations of backpropagation learning can now be overcome by using multilayer neural networks that contain top-down connections and training them to generate sensory data rather than to classify it. Learning multilayer generative models might seem difficult, but a recent discovery makes it easy to learn nonlinear distributed representations one layer at a time. PMID:17921042

  20. The Statistics of Visual Representation

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The experience of retinex image processing has prompted us to reconsider fundamental aspects of imaging and image processing. Foremost is the idea that a good visual representation requires a non-linear transformation of the recorded (approximately linear) image data. Further, this transformation appears to converge on a specific distribution. Here we investigate the connection between numerical and visual phenomena. Specifically the questions explored are: (1) Is there a well-defined consistent statistical character associated with good visual representations? (2) Does there exist an ideal visual image? And (3) what are its statistical properties?

  1. Acquired Equivalence Changes Stimulus Representations

    ERIC Educational Resources Information Center

    Meeter, M.; Shohamy, D.; Myers, C. E.

    2009-01-01

    Acquired equivalence is a paradigm in which generalization is increased between two superficially dissimilar stimuli (or antecedents) that have previously been associated with similar outcomes (or consequents). Several possible mechanisms have been proposed, including changes in stimulus representations, either in the form of added associations or…

  2. A qualia representation of cyberspace

    NASA Astrophysics Data System (ADS)

    Lacey, Timothy H.; Mills, Robert F.; Raines, Richard A.; Oxley, Mark E.; Bauer, Kenneth W.; Rogers, Steven K.

    2008-04-01

    E.C Adam defined Situational Awareness (SA) as "the mental representation and understanding of objects, events, people, system states, interactions, environmental conditions, and other situation-specific factors affecting human performance in complex and dynamic tasks. Stated in lay terms, SA is simply knowing what is going on so you can figure out what to do." We propose a novel idea to assist the human in gaining SA. Our hypothesis is that nature uses qualia as a compression scheme to represent the many concepts encountered in everyday life. Qualia enable humans to quickly come up with SA based on many complex measurements from their sensors, (eyes, ears, taste, touch, memory, etc.), expectations, and experiences. Our ultimate objective is to develop a computer that uses qualia concepts to transform sensor data to assist the human in gaining and maintaining improved SA. However, before any computer can use qualia, we must first define a representation for qualia that can be implemented computationally. This paper will present our representation for qualia. The representation is not simply a hierarchical aggregation of input data. Instead, it is a prediction of what will happen next, derived from computations resulting from sensory inputs and the computational engine of a qualia generator and qualia processor.

  3. Mental Representations of Social Status

    ERIC Educational Resources Information Center

    Chiao, Joan Y.; Bordeaux, Andrew R.; Ambady, Nalni

    2004-01-01

    How do people think about social status? We investigated the nature of social status and number representations using a semantic distance latency test. In Study 1, 21 college students compared words connoting different social status as well as numbers, which served as a control task. Participants were faster at comparing occupations and numbers…

  4. Lie antialgebras: cohomology and representations

    SciTech Connect

    Ovsienko, V.

    2008-11-18

    We describe the main algebraic and geometric properties of the class of algebras introduced in [1]. We discuss their origins in symplectic geometry and associative algebra, and the notions of cohomology and representations. We formulate classification theorems and give a number of examples.

  5. Grobner Basis Representations of Sudoku

    ERIC Educational Resources Information Center

    Taalman, Laura; Arnold, Elizabeth; Lucas, Stephen

    2010-01-01

    This paper uses Grobner bases to explore the inherent structure of Sudoku puzzles and boards. In particular, we develop three different ways of representing the constraints of Sudoku puzzles with a system of polynomial equations. In one case, we explicitly show how a Grobner basis can be used to obtain a more meaningful representation of the…

  6. Correct Representation of Conformational Equilibria.

    ERIC Educational Resources Information Center

    Fulop, F.; And Others

    1983-01-01

    In representing conformational equilibria of compounds having only one chiral center, erroneous formulas showing different antipodes on the two sides of the equilibrium are rare. In contrast, with compounds having two or more chiral centers especially with saturated heterocycles, this erroneous representation occurs frequently in the chemical…

  7. Representational Momentum in Older Adults

    ERIC Educational Resources Information Center

    Piotrowski, Andrea S.; Jakobson, Lorna S.

    2011-01-01

    Humans have a tendency to perceive motion even in static images that simply "imply" movement. This tendency is so strong that our memory for actions depicted in static images is distorted in the direction of implied motion--a phenomenon known as representational momentum (RM). In the present study, we created an RM display depicting a pattern of…

  8. Knowledge representation in fuzzy logic

    NASA Technical Reports Server (NTRS)

    Zadeh, Lotfi A.

    1989-01-01

    The author presents a summary of the basic concepts and techniques underlying the application of fuzzy logic to knowledge representation. He then describes a number of examples relating to its use as a computational system for dealing with uncertainty and imprecision in the context of knowledge, meaning, and inference. It is noted that one of the basic aims of fuzzy logic is to provide a computational framework for knowledge representation and inference in an environment of uncertainty and imprecision. In such environments, fuzzy logic is effective when the solutions need not be precise and/or it is acceptable for a conclusion to have a dispositional rather than categorical validity. The importance of fuzzy logic derives from the fact that there are many real-world applications which fit these conditions, especially in the realm of knowledge-based systems for decision-making and control.

  9. Sparse representation for vehicle recognition

    NASA Astrophysics Data System (ADS)

    Monnig, Nathan D.; Sakla, Wesam

    2014-06-01

    The Sparse Representation for Classification (SRC) algorithm has been demonstrated to be a state-of-the-art algorithm for facial recognition applications. Wright et al. demonstrate that under certain conditions, the SRC algorithm classification performance is agnostic to choice of linear feature space and highly resilient to image corruption. In this work, we examined the SRC algorithm performance on the vehicle recognition application, using images from the semi-synthetic vehicle database generated by the Air Force Research Laboratory. To represent modern operating conditions, vehicle images were corrupted with noise, blurring, and occlusion, with representation of varying pose and lighting conditions. Experiments suggest that linear feature space selection is important, particularly in the cases involving corrupted images. Overall, the SRC algorithm consistently outperforms a standard k nearest neighbor classifier on the vehicle recognition task.

  10. Ephemeris representations for communications satellites

    NASA Astrophysics Data System (ADS)

    Proulx, R. J.; Cefola, P. J.; McClain, W. D.

    1984-08-01

    Large orbit determination (OD) centers are the primary source of artificial satellite ephemeris data. The ephemeris message of the OD facility contains implicitly the predicted satellite trajectory. The user can recover ephemeris data on the basis of two conceptual approaches. The current investigation is concerned with an alternative solution to the ephemeris representation problem. According to the procedure employed in this case, the mean equinoctial element time histories corresponding to the predicted satellite trajectory generated by the OD facility are approximated by low degree Legendre polynomials to represent their secular behavior and by trigonometric terms to represent their mean periodic behavior. This approach provides a simple, low cost, and accurate ephemeris representation, which satisfies the potential autonomy requirements for Military Satellite Communications.

  11. Berry phase in Heisenberg representation

    NASA Technical Reports Server (NTRS)

    Andreev, V. A.; Klimov, Andrei B.; Lerner, Peter B.

    1994-01-01

    We define the Berry phase for the Heisenberg operators. This definition is motivated by the calculation of the phase shifts by different techniques. These techniques are: the solution of the Heisenberg equations of motion, the solution of the Schrodinger equation in coherent-state representation, and the direct computation of the evolution operator. Our definition of the Berry phase in the Heisenberg representation is consistent with the underlying supersymmetry of the model in the following sense. The structural blocks of the Hamiltonians of supersymmetrical quantum mechanics ('superpairs') are connected by transformations which conserve the similarity in structure of the energy levels of superpairs. These transformations include transformation of phase of the creation-annihilation operators, which are generated by adiabatic cyclic evolution of the parameters of the system.

  12. Representations of mad cow disease.

    PubMed

    Washer, Peter

    2006-01-01

    This paper examines the reporting of the story of Bovine Spongiform Encephalopathy (BSE) and its human derivative variant Creutzfeld-Jacob Disease (vCJD) in the British newspapers. Three 'snapshots' of newspaper coverage are sampled and analysed between the period 1986 and 1996 focusing on how representations of the disease evolved over the 10-year period. Social representations theory is used to elucidate how this new disease threat was conceptualised in the newspaper reporting and how it was explained to the UK public. This paper examines who or what was said to be at risk from the new disease, and whether some individuals or groups held to blame for the diseases' putative origins, the appearance of vCJD in human beings, and its spread. PMID:16046039

  13. Representations to support terrain reasoning

    SciTech Connect

    Powell, D.R.; Wright, J.C.; Slentz, G.E.; Knudsen, P.D.

    1988-01-01

    Los Alamos National Laboratory has been cooperating with the Training and Doctrine Command of the US Army to develop a Corps level combat simulation for quick turn around studies. The simulation of ground combat requires representation of combat units, unit activities, command and control, and terrain. This simulation model emphasizes command and control with particular attention to the potential for automating operational planning. As terrain analysis is an essential part of Army operational planning, this has direct influence on the representation of terrain. The availability of digitized terrain makes it feasible to apply computer based techniques to emulate the terrain analysis process for use in the planning cycle. This paper describes processes used to calculate relevant terrain features for use in a simulation model. 13 refs., 6 figs., 6 tabs.

  14. Free boundary ballooning mode representation

    SciTech Connect

    Zheng, L. J.

    2012-10-15

    A new type of ballooning mode invariance is found in this paper. Application of this invariance is shown to be able to reduce the two-dimensional problem of free boundary high n modes, such as the peeling-ballooning modes, to a one-dimensional problem. Here, n is toroidal mode number. In contrast to the conventional ballooning representation, which requires the translational invariance of the Fourier components of the perturbations, the new invariance reflects that the independent solutions of the high n mode equations are translationally invariant from one radial interval surrounding a single singular surface to the other intervals. The conventional ballooning mode invariance breaks down at the vicinity of plasma edge, since the Fourier components with rational surfaces in vacuum region are completely different from those with rational surfaces in plasma region. But, the new type of invariance remains valid. This overcomes the limitation of the conventional ballooning mode representation for studying free boundary modes.

  15. Time representations in social science

    PubMed Central

    Schulz, Yvan

    2012-01-01

    Time has long been a major topic of study in social science, as in other sciences or in philosophy. Social scientists have tended to focus on collective representations of time, and on the ways in which these representations shape our everyday experiences. This contribution addresses work from such disciplines as anthropology, sociology and history. It focuses on several of the main theories that have preoccupied specialists in social science, such as the alleged “acceleration” of life and overgrowth of the present in contemporary Western societies, or the distinction between so-called linear and circular conceptions of time. The presentation of these theories is accompanied by some of the critiques they have provoked, in order to enable the reader to form her or his own opinion of them. PMID:23393420

  16. SAR Image Complex Pixel Representations

    SciTech Connect

    Doerry, Armin W.

    2015-03-01

    Complex pixel values for Synthetic Aperture Radar (SAR) images of uniform distributed clutter can be represented as either real/imaginary (also known as I/Q) values, or as Magnitude/Phase values. Generally, these component values are integers with limited number of bits. For clutter energy well below full-scale, Magnitude/Phase offers lower quantization noise than I/Q representation. Further improvement can be had with companding of the Magnitude value.

  17. Temporal Representation in Semantic Graphs

    SciTech Connect

    Levandoski, J J; Abdulla, G M

    2007-08-07

    A wide range of knowledge discovery and analysis applications, ranging from business to biological, make use of semantic graphs when modeling relationships and concepts. Most of the semantic graphs used in these applications are assumed to be static pieces of information, meaning temporal evolution of concepts and relationships are not taken into account. Guided by the need for more advanced semantic graph queries involving temporal concepts, this paper surveys the existing work involving temporal representations in semantic graphs.

  18. Fock representation for quaternion fields

    SciTech Connect

    Govorkov, A.B.

    1987-04-01

    A Fock representation is determined for a nonrelativistic self-adjoint (Majorana) field based on quaternions, and the quantum mechanics of the parafermions of third order corresponding to it is formulated. Attention is drawn to the difference between the gauge pseudocolor SO(3) symmetry of the automorphisms of such a field and the global SU(3) symmetry of the states of the particles corresponding to it in the Fock space.

  19. Computational representation of biological systems

    SciTech Connect

    Frazier, Zach; McDermott, Jason E.; Guerquin, Michal; Samudrala, Ram

    2009-04-20

    Integration of large and diverse biological data sets is a daunting problem facing systems biology researchers. Exploring the complex issues of data validation, integration, and representation, we present a systematic approach for the management and analysis of large biological data sets based on data warehouses. Our system has been implemented in the Bioverse, a framework combining diverse protein information from a variety of knowledge areas such as molecular interactions, pathway localization, protein structure, and protein function.

  20. Representations of metabolic knowledge: pathways.

    PubMed

    Karp, P D; Paley, S M

    1994-01-01

    The automatic generation of drawings of metabolic pathways is a challenging problem that depends intimately on exactly what information has been recorded for each pathway, and on how that information is encoded. The chief contributions of the paper are a minimized representation for biochemical pathways called the predecessor list, and inference procedures for converting the predecessor list into a pathway-graph representation that can serve as input to a pathway-drawing algorithm. The predecessor list has several advantages over the pathway graph, including its compactness and its lack of redundancy. The conversion between the two representations can be formulated as both a constraint-satisfaction problem and a logical inference problem, whose goal is to assign directions to reactions, and to determine which are the main chemical compounds in the reaction. We describe a set of production rules that solves this inference problem. We also present heuristics for inferring whether the exterior compounds that are substrates of reactions at the periphery of a pathway are side or main compounds. These techniques were evaluated on 18 metabolic pathways from the EcoCyc knowledge base. PMID:7584392

  1. On Performance Skill Representation Framework

    NASA Astrophysics Data System (ADS)

    Furukawa, Koichi; Shimizu, Satoshi; Yoshinaga, Saori

    In this paper, we propose a framework for representing performance skill. Firstly, we notice the importance of performance skill representation. We introduce five different representation targets: performance tasks, performance rules, pre-shaping actions, dynamic integrity constraints, and performance states. Performance task description consists of a sequence of performance tasks and expressions. It acts as a goal description in planning. Performance rules describe model performance methods for given tasks including how to shape body parts and how to use various muscles. Pre-shaping action rules are similar to performance rules. Its role is to pre-shape in between consecutive tasks to prepare for the next task. Dynamic integrity constraints specify constraints to be satisfied during performance. They provide such general rules as prohibiting simultaneous strong activations of agonist and antagonist. Performance states are for describing real performance done by players including professionals and amateurs. The aim of the framework is to provide a uniform scheme for representing model performance methods given performance score such as music score. The representation framework will define targets of inducing formal skill rules as well as describing performance states automatically from biomechanical performance data. It also is related to a fundamental research issue of attributes finding/selection in discovering useful rules for skillful performance. We conclude our paper by stating future research direction.

  2. Body representations and brain damage.

    PubMed

    Rousseaux, M; Honoré, J; Saj, A

    2014-01-01

    We review changes in body representation in patients with brain hemisphere damage and discuss their relationship with impaired limb movements in peripersonal space, navigation between objects/obstacles and control of the body's general posture and balance. The egocentric representation of the body's median sagittal axis (considered as the main zone around which movements are anchored) has been studied in most detail. This reference is distorted in patients with spatial neglect and involves a combination of ipsilesional translation and contralesional tilt. There are clear links with the patients' difficulties in egocentric tasks, activities of daily living and postural control. In both healthy subjects and patients, this reference axis can be modulated by somaesthetic, vestibular and visual stimulations; these phenomena have been used in rehabilitation programmes to reduce disease-induced deviations. A few studies have analyzed other lateral body reference (at the shoulders, in particular). These references were found to be more severely affected than the body midline (notably on the contralesional side). The severity of the distortion was related to the presence of lesions that mainly affected the parietal, somatosensory and multimodal association cortex (notably around the intraparietal sulcus) and, to a lesser extent, the middle temporal and frontal dorsolateral premotor cortex. These convergent results suggested that patients (notably those with neglect) have a complex distortion of the body schema and the perceptive representations of the body, that does not simply correspond to poor awareness of the contralateral hemicorpus. PMID:24502906

  3. Learning Sparse Representations of Depth

    NASA Astrophysics Data System (ADS)

    Tosic, Ivana; Olshausen, Bruno A.; Culpepper, Benjamin J.

    2011-09-01

    This paper introduces a new method for learning and inferring sparse representations of depth (disparity) maps. The proposed algorithm relaxes the usual assumption of the stationary noise model in sparse coding. This enables learning from data corrupted with spatially varying noise or uncertainty, typically obtained by laser range scanners or structured light depth cameras. Sparse representations are learned from the Middlebury database disparity maps and then exploited in a two-layer graphical model for inferring depth from stereo, by including a sparsity prior on the learned features. Since they capture higher-order dependencies in the depth structure, these priors can complement smoothness priors commonly used in depth inference based on Markov Random Field (MRF) models. Inference on the proposed graph is achieved using an alternating iterative optimization technique, where the first layer is solved using an existing MRF-based stereo matching algorithm, then held fixed as the second layer is solved using the proposed non-stationary sparse coding algorithm. This leads to a general method for improving solutions of state of the art MRF-based depth estimation algorithms. Our experimental results first show that depth inference using learned representations leads to state of the art denoising of depth maps obtained from laser range scanners and a time of flight camera. Furthermore, we show that adding sparse priors improves the results of two depth estimation methods: the classical graph cut algorithm by Boykov et al. and the more recent algorithm of Woodford et al.

  4. Neural Representations of Physics Concepts.

    PubMed

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems. PMID:27113732

  5. Double groups and projective representations

    NASA Astrophysics Data System (ADS)

    Altmann, S. L.; Herzig, P.

    Some problems are discussed in relation to the usual treatment of improper groups through their double groups, in particular the identification (rather than the mere isomorphism) of such groups as C3v and D3. The enhancement of SU(2) by the addition of the inversion is analysed for this purpose. This requires a careful discussion of the behaviour of spinors under inversion and two types of spinors are defined, Cartan and Pauli spinors, that behave differently with respect to inversion, although it is shown that this difference merely entails a choice of gauge in the language of projective representations. A distinction is proposed between the inversion operation and the parity operator: when the former is realized as a binary rotation in 4-space, the latter can be identified with its infinitesimal generator. The passage from SO(3) to O(3) (group of all proper and improper rotations) is studied and a hitherto unknown faithful projective representations of O(3) is given. It is shown how spinor representations can be constructed for improper point groups in either the Cartan or Pauli gauges. A choice of gauge is proposed to ensure agreement with current practice in angular momentum theory and with that in single point groups. As an example, Clebsch-Gordan coefficients are constructed for C3v.

  6. Representation of ideal magnetohydrodynamic modes

    SciTech Connect

    White, R. B.

    2013-02-15

    One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through {delta}B(vector sign)={nabla} Multiplication-Sign ({xi}(vector sign) Multiplication-Sign B(vector sign)) ensures that {delta}B(vector sign){center_dot}{nabla}{psi}=0 at a resonance, with {psi} labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation {delta}B(vector sign)={nabla} Multiplication-Sign {alpha}B(vector sign). These two representations are equivalent, but the vanishing of {delta}B(vector sign){center_dot}{nabla}{psi} at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in {xi}(vector sign) to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed.

  7. Connected Representations: From Proportion to Linear Functions

    ERIC Educational Resources Information Center

    Baltus, Christopher

    2010-01-01

    Mathematics may be inconceivable without its diagrams and symbols--its representations. Mathematical representations help individuals organize their thinking; they bring a visual component to abstract ideas and serve as templates for computation with understanding. But the inevitability of representations is no guarantee that they are used…

  8. Imitation and the Dialectic of Representation.

    ERIC Educational Resources Information Center

    Zelazo, Philip David; Lourenco, Stella Felix

    2003-01-01

    Describes a theory of the understanding and use of representations, drawing heavily on Paul Ricoeur's and James Mark Baldwin's theories. Presents this theory as construing representation as intrinsically mimetic, characterizing the development of representational understanding as internalization, and emphasizing the importance of self-reflection…

  9. 48 CFR 1480.802 - Representation provision.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Representation provision... AFFAIRS SUPPLEMENT ACQUISITIONS UNDER THE BUY INDIAN ACT Representation by an Indian Economic Enterprise Offeror 1480.802 Representation provision. (a) IA contracting offices must provide copies of the...

  10. 48 CFR 1480.802 - Representation provision.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Representation provision... AFFAIRS SUPPLEMENT ACQUISITIONS UNDER THE BUY INDIAN ACT Representation by an Indian Economic Enterprise Offeror 1480.802 Representation provision. (a) IA contracting offices must provide copies of the...

  11. Methods and Strategies: The Science Representation Continuum

    ERIC Educational Resources Information Center

    Olson, Joanne K.

    2008-01-01

    Research indicates that people more easily understand abstractions when they are preceded by concrete representations (Lawson 2002). This article describes how educators can use science representations to help students form lasting understandings of abstract concepts. A spectrum illustrating some commonly used representation types and their level…

  12. Promoting Decimal Number Sense and Representational Fluency

    ERIC Educational Resources Information Center

    Suh, Jennifer M.; Johnston, Chris; Jamieson, Spencer; Mills, Michelle

    2008-01-01

    The abstract nature of mathematics requires the communication of mathematical ideas through multiple representations, such as words, symbols, pictures, objects, or actions. Building representational fluency involves using mathematical representations flexibly and being able to interpret and translate among these different models and mathematical…

  13. Solution Representations and Pedagogical Representations in Chinese and U.S. Classrooms

    ERIC Educational Resources Information Center

    Cai, Jinfa; Lester, Frank K., Jr.

    2005-01-01

    This study involved an investigation of the relationship between the kinds of solution representations Chinese and U.S. students use and the sorts of pedagogical representations Chinese and U.S. teachers use during instruction. The findings suggest that the representations teachers use influence the representations their students use and, hence,…

  14. Negotiated Representational Mediators: How Young Children Decide What to Include in Their Science Representations

    ERIC Educational Resources Information Center

    Danish, Joshua A.; Enyedy, Noel

    2007-01-01

    In this paper, we synthesize two bodies of work related to students' representational activities: the notions of meta-representational competence and representation as a form of practice. We report on video analyses of kindergarten and first-grade students as they create representations of pollination in a science classroom, as well as summarize…

  15. Alternative Approach to Nuclear Data Representation

    SciTech Connect

    Pruet, J; Brown, D; Beck, B; McNabb, D P

    2005-07-27

    This paper considers an approach for representing nuclear data that is qualitatively different from the approach currently adopted by the nuclear science community. Specifically, they examine a representation in which complicated data is described through collections of distinct and self contained simple data structures. This structure-based representation is compared with the ENDF and ENDL formats, which can be roughly characterized as dictionary-based representations. A pilot data representation for replacing the format currently used at LLNL is presented. Examples are given as is a discussion of promises and shortcomings associated with moving from traditional dictionary-based formats to a structure-rich or class-like representation.

  16. Unitary Representations of Gauge Groups

    NASA Astrophysics Data System (ADS)

    Huerfano, Ruth Stella

    I generalize to the case of gauge groups over non-trivial principal bundles representations that I. M. Gelfand, M. I. Graev and A. M. Versik constructed for current groups. The gauge group of the principal G-bundle P over M, (G a Lie group with an euclidean structure, M a compact, connected and oriented manifold), as the smooth sections of the associated group bundle is presented and studied in chapter I. Chapter II describes the symmetric algebra associated to a Hilbert space, its Hilbert structure, a convenient exponential and a total set that later play a key role in the construction of the representation. Chapter III is concerned with the calculus needed to make the space of Lie algebra valued 1-forms a Gaussian L^2-space. This is accomplished by studying general projective systems of finitely measurable spaces and the corresponding systems of sigma -additive measures, all of these leading to the description of a promeasure, a concept modeled after Bourbaki and classical measure theory. In the case of a locally convex vector space E, the corresponding Fourier transform, family of characters and the existence of a promeasure for every quadratic form on E^' are established, so the Gaussian L^2-space associated to a real Hilbert space is constructed. Chapter III finishes by exhibiting the explicit Hilbert space isomorphism between the Gaussian L ^2-space associated to a real Hilbert space and the complexification of its symmetric algebra. In chapter IV taking as a Hilbert space H the L^2-space of the Lie algebra valued 1-forms on P, the gauge group acts on the motion group of H defining in an straight forward fashion the representation desired.

  17. Neural representation of probabilistic information.

    PubMed

    Barber, M J; Clark, J W; Anderson, C H

    2003-08-01

    It has been proposed that populations of neurons process information in terms of probability density functions (PDFs) of analog variables. Such analog variables range, for example, from target luminance and depth on the sensory interface to eye position and joint angles on the motor output side. The requirement that analog variables must be processed leads inevitably to a probabilistic description, while the limited precision and lifetime of the neuronal processing units lead naturally to a population representation of information. We show how a time-dependent probability density rho(x; t) over variable x, residing in a specified function space of dimension D, may be decoded from the neuronal activities in a population as a linear combination of certain decoding functions phi(i)(x), with coefficients given by the N firing rates a(i)(t) (generally with D < N). We show how the neuronal encoding process may be described by projecting a set of complementary encoding functions phi;(i)(x) on the probability density rho(x; t), and passing the result through a rectifying nonlinear activation function. We show how both encoders phi;(i)(x) and decoders phi(i)(x) may be determined by minimizing cost functions that quantify the inaccuracy of the representation. Expressing a given computation in terms of manipulation and transformation of probabilities, we show how this representation leads to a neural circuit that can carry out the required computation within a consistent Bayesian framework, with the synaptic weights being explicitly generated in terms of encoders, decoders, conditional probabilities, and priors. PMID:14511515

  18. Quantum correlations and tomographic representation

    NASA Astrophysics Data System (ADS)

    Man'ko, O. V.; Chernega, V. N.

    2013-07-01

    We review the probabilistic representation of quantum mechanics within which states are described by the probability distribution rather than by the wavefunction and density matrix. Uncertainty relations have been obtained in the form of integral inequalities containing measurable optical tomograms of quantum states. Formulas for the transition probabilities and purity parameter have been derived in terms of the tomographic probability distributions. Inequalities for Shannon and Rényi entropies associated with quantum tomograms have been obtained. A scheme of the star product of tomograms has been developed.

  19. Superalgebraic representation of Dirac matrices

    NASA Astrophysics Data System (ADS)

    Monakhov, V. V.

    2016-01-01

    We consider a Clifford extension of the Grassmann algebra in which operators are constructed from products of Grassmann variables and derivatives with respect to them. We show that this algebra contains a subalgebra isomorphic to a matrix algebra and that it additionally contains operators of a generalized matrix algebra that mix states with different numbers of Grassmann variables. We show that these operators are extensions of spin-tensors to the case of superspace. We construct a representation of Dirac matrices in the form of operators of a generalized matrix algebra.

  20. Efficient Type Representation in TAL

    NASA Technical Reports Server (NTRS)

    Chen, Juan

    2009-01-01

    Certifying compilers generate proofs for low-level code that guarantee safety properties of the code. Type information is an essential part of safety proofs. But the size of type information remains a concern for certifying compilers in practice. This paper demonstrates type representation techniques in a large-scale compiler that achieves both concise type information and efficient type checking. In our 200,000-line certifying compiler, the size of type information is about 36% of the size of pure code and data for our benchmarks, the best result to the best of our knowledge. The type checking time is about 2% of the compilation time.

  1. Argumentation-Based Collaborative Inquiry in Science Through Representational Work: Impact on Primary Students' Representational Fluency

    NASA Astrophysics Data System (ADS)

    Nichols, Kim; Gillies, Robyn; Hedberg, John

    2016-06-01

    This study explored the impact of argumentation-promoting collaborative inquiry and representational work in science on primary students' representational fluency. Two hundred sixty-six year 6 students received instruction on natural disasters with a focus on collaborative inquiry. Students in the Comparison condition received only this instruction. Students in the Explanation condition were also instructed with a focus on explanations using representations. Students in the Argumentation condition received similar instruction to the Comparison and Explanation conditions but were also instructed with a focus on argumentation using representations. Conceptual understanding and representational competencies (interpreting, explaining and constructing representations) were measured prior to and immediately following the instruction. A small group collaborative representational task was video recorded at the end of the instruction and coded for modes of knowledge-building discourse; knowledge-sharing and knowledge-construction. Higher measures of conceptual understanding, representational competencies and knowledge-construction discourse were taken together as representational fluency. Students in all conditions showed significant improvement in conceptual understanding, interpreting representations and explaining representations. Students in the Comparison and Argumentation conditions also showed significantly improved scores in constructing representations. When compared to the other conditions, the Explanation group had the highest scores in conceptual understanding and also interpreting and explaining representations. While the Argumentation group had the highest scores for constructing representations, their scores for conceptual understanding as well as interpreting and explaining representations were also high. There was no difference between the groups in knowledge-sharing discourse; however, the Argumentation group displayed the highest incidence of knowledge

  2. On volume-source representations based on the representation theorem

    NASA Astrophysics Data System (ADS)

    Ichihara, Mie; Kusakabe, Tetsuya; Kame, Nobuki; Kumagai, Hiroyuki

    2016-01-01

    We discuss different ways to characterize a moment tensor associated with an actual volume change of ΔV C , which has been represented in terms of either the stress glut or the corresponding stress-free volume change ΔV T . Eshelby's virtual operation provides a conceptual model relating ΔV C to ΔV T and the stress glut, where non-elastic processes such as phase transitions allow ΔV T to be introduced and subsequent elastic deformation of - ΔV T is assumed to produce the stress glut. While it is true that ΔV T correctly represents the moment tensor of an actual volume source with volume change ΔV C , an explanation as to why such an operation relating ΔV C to ΔV T exists has not previously been given. This study presents a comprehensive explanation of the relationship between ΔV C and ΔV T based on the representation theorem. The displacement field is represented using Green's function, which consists of two integrals over the source surface: one for displacement and the other for traction. Both integrals are necessary for representing volumetric sources, whereas the representation of seismic faults includes only the first term, as the second integral over the two adjacent fault surfaces, across which the traction balances, always vanishes. Therefore, in a seismological framework, the contribution from the second term should be included as an additional surface displacement. We show that the seismic moment tensor of a volume source is directly obtained from the actual state of the displacement and stress at the source without considering any virtual non-elastic operations. A purely mathematical procedure based on the representation theorem enables us to specify the additional imaginary displacement necessary for representing a volume source only by the displacement term, which links ΔV C to ΔV T . It also specifies the additional imaginary stress necessary for representing a moment tensor solely by the traction term, which gives the "stress glut." The

  3. Visual representations of Iranian transgenders.

    PubMed

    Shakerifar, Elhum

    2011-01-01

    Transsexuality in Iran has gained much attention and media coverage in the past few years, particularly in its questionable depiction as a permitted loophole for homosexuality, which is prohibited under Iran's Islamic-inspired legal system. Of course, attention in the West is also encouraged by the “shock” that sex change is available in Iran, a country that Western media and society delights in portraying as monolithically repressive. As a result, Iranian filmmakers inevitably have their own agendas, which are unsurprisingly brought into the film making process—from a desire to sell a product that will appeal to the Western market, to films that endorse specific socio-political agendas. This paper is an attempt to situate sex change and representations of sex change in Iran within a wider theoretical framework than the frequently reiterated conflation with homosexuality, and to open and engage with a wider debate concerning transsexuality in Iran, as well as to specifically analyze the representation of transexuality, in view of its current prominent presence in media. PMID:21910275

  4. Spatial Representation of Ordinal Information

    PubMed Central

    Zhang, Meng; Gao, Xuefei; Li, Baichen; Yu, Shuyuan; Gong, Tianwei; Jiang, Ting; Hu, Qingfen; Chen, Yinghe

    2016-01-01

    Right hand responds faster than left hand when shown larger numbers and vice-versa when shown smaller numbers (the SNARC effect). Accumulating evidence suggests that the SNARC effect may not be exclusive for numbers and can be extended to other ordinal sequences (e.g., months or letters in the alphabet) as well. In this study, we tested the SNARC effect with a non-numerically ordered sequence: the Chinese notations for the color spectrum (Red, Orange, Yellow, Green, Blue, Indigo, and Violet). Chinese color word sequence reserves relatively weak ordinal information, because each element color in the sequence normally appears in non-sequential contexts, making it ideal to test the spatial organization of sequential information that was stored in the long-term memory. This study found a reliable SNARC-like effect for Chinese color words (deciding whether the presented color word was before or after the reference color word “green”), suggesting that, without access to any quantitative information or exposure to any previous training, ordinal representation can still activate a sense of space. The results support that weak ordinal information without quantitative magnitude encoded in the long-term memory can activate spatial representation in a comparison task. PMID:27092100

  5. Spatial Representation of Ordinal Information.

    PubMed

    Zhang, Meng; Gao, Xuefei; Li, Baichen; Yu, Shuyuan; Gong, Tianwei; Jiang, Ting; Hu, Qingfen; Chen, Yinghe

    2016-01-01

    Right hand responds faster than left hand when shown larger numbers and vice-versa when shown smaller numbers (the SNARC effect). Accumulating evidence suggests that the SNARC effect may not be exclusive for numbers and can be extended to other ordinal sequences (e.g., months or letters in the alphabet) as well. In this study, we tested the SNARC effect with a non-numerically ordered sequence: the Chinese notations for the color spectrum (Red, Orange, Yellow, Green, Blue, Indigo, and Violet). Chinese color word sequence reserves relatively weak ordinal information, because each element color in the sequence normally appears in non-sequential contexts, making it ideal to test the spatial organization of sequential information that was stored in the long-term memory. This study found a reliable SNARC-like effect for Chinese color words (deciding whether the presented color word was before or after the reference color word "green"), suggesting that, without access to any quantitative information or exposure to any previous training, ordinal representation can still activate a sense of space. The results support that weak ordinal information without quantitative magnitude encoded in the long-term memory can activate spatial representation in a comparison task. PMID:27092100

  6. Representation and Re-Presentation in Litigation Science

    PubMed Central

    Jasanoff, Sheila

    2008-01-01

    Federal appellate courts have devised several criteria to help judges distinguish between reliable and unreliable scientific evidence. The best known are the U.S. Supreme Court’s criteria offered in 1993 in Daubert v. Merrell Dow Pharmaceuticals, Inc. This article focuses on another criterion, offered by the Ninth Circuit Court of Appeals, that instructs judges to assign lower credibility to “litigation science” than to science generated before litigation. In this article I argue that the criterion-based approach to judicial screening of scientific evidence is deeply flawed. That approach buys into the faulty premise that there are external criteria, lying outside the legal process, by which judges can distinguish between good and bad science. It erroneously assumes that judges can ascertain the appropriate criteria and objectively apply them to challenged evidence before litigation unfolds, and before methodological disputes are sorted out during that process. Judicial screening does not take into account the dynamics of litigation itself, including gaming by the parties and framing by judges, as constitutive factors in the production and representation of knowledge. What is admitted through judicial screening, in other words, is not precisely what a jury would see anyway. Courts are sites of repeated re-representations of scientific knowledge. In sum, the screening approach fails to take account of the wealth of existing scholarship on the production and validation of scientific facts. An unreflective application of that approach thus puts courts at risk of relying upon a “junk science” of the nature of scientific knowledge. PMID:18197311

  7. Extended loop representation of quantum gravity

    SciTech Connect

    Di Bartolo, C. ); Gambini, R.; Griego, J. )

    1995-01-15

    A new representation of quantum gravity is developed. This formulation is based on an extension of the group of loops. The enlarged group that we call the extended loop group behaves locally as an infinite dimensional Lie group. Quantum gravity can be realized on the state space of extended loop-dependent wave functions. The extended representation generalizes the loop representation and contains this representation as a particular case. The resulting diffeomorphism and Hamiltonian constraints take a very simple form and allow us to apply functional methods and simplify the loop calculus. In particular we show that the constraints are linear in the momenta. The nondegenerate solutions known in the loop representation are also solutions of the constraints in the new representation. An approach to the regularization problems associated with the formal calculus is performed. We show that the solutions are generalized knot invariants, smooth in the extended variables, and any framing is unnecessary.

  8. Braid group representation on quantum computation

    SciTech Connect

    Aziz, Ryan Kasyfil; Muchtadi-Alamsyah, Intan

    2015-09-30

    There are many studies about topological representation of quantum computation recently. One of diagram representation of quantum computation is by using ZX-Calculus. In this paper we will make a diagrammatical scheme of Dense Coding. We also proved that ZX-Calculus diagram of maximally entangle state satisfies Yang-Baxter Equation and therefore, we can construct a Braid Group representation of set of maximally entangle state.

  9. Attitude Error Representations for Kalman Filtering

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The quaternion has the lowest dimensionality possible for a globally nonsingular attitude representation. The quaternion must obey a unit norm constraint, though, which has led to the development of an extended Kalman filter using a quaternion for the global attitude estimate and a three-component representation for attitude errors. We consider various attitude error representations for this Multiplicative Extended Kalman Filter and its second-order extension.

  10. Precedence relationship representations of mechanical assembly sequences

    NASA Technical Reports Server (NTRS)

    Homendemello, L. S.; Sanderson, A. C.

    1989-01-01

    Two types of precedence relationship representations for mechanical assembly sequences are presented: precedence relationships between the establishment of one connection between two parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process. Precedence relationship representations have the advantage of being very compact. The problem with these representations was how to guarantee their correctness and completeness. Two theorems are presented each of which leads to the generation of one type of precedence relationship representation guaranteeing its correctness and completeness for a class of assemblies.

  11. Standardization of beam line representations

    NASA Astrophysics Data System (ADS)

    Carey, David C.

    1999-05-01

    Standardization of beam line representations means that a single set of data can be used in many situations to represent a beam line. This set of data should be the same no matter what the program to be run or the calculation to be made. We have concerned ourselves with three types of standardization: (1) The same set of data should be usable by different programs. (2) The inclusion of other items in the data, such as calculations to be done, units to be used, or preliminary specifications, should be in a notation similar to the lattice specification. (3) A single set of data should be used to represent a given beam line, no matter what is being modified or calculated. The specifics of what is to be modified or calculated can be edited into the data as part of the calculation. These three requirements all have aspects not previously discussed in a public forum. Implementations into TRANSPORT [1] will be discussed.

  12. SLE and Virasoro Representations: Fusion

    NASA Astrophysics Data System (ADS)

    Dubédat, Julien

    2015-06-01

    We continue the study of null-vector equations in relation with partition functions of (systems of) Schramm-Loewner Evolutions (SLEs) by considering the question of fusion. Starting from n commuting SLEs seeded at distinct points, the partition function satisfies n null-vector equations (at level 2). We show how to obtain higher level null-vector equations by coalescing the seeds one by one. As an example, we extend Schramm's formula (for the position of a marked bulk point relatively to a chordal SLE trace) to an arbitrary number of SLE strands. The argument combines input from representation theory—the study of Verma modules for the Virasoro algebra—with regularity estimates, themselves based on hypoellipticity and stochastic flow arguments.

  13. Wavelet Representation of Contour Sets

    SciTech Connect

    Bertram, M; Laney, D E; Duchaineau, M A; Hansen, C D; Hamann, B; Joy, K I

    2001-07-19

    We present a new wavelet compression and multiresolution modeling approach for sets of contours (level sets). In contrast to previous wavelet schemes, our algorithm creates a parametrization of a scalar field induced by its contoum and compactly stores this parametrization rather than function values sampled on a regular grid. Our representation is based on hierarchical polygon meshes with subdivision connectivity whose vertices are transformed into wavelet coefficients. From this sparse set of coefficients, every set of contours can be efficiently reconstructed at multiple levels of resolution. When applying lossy compression, introducing high quantization errors, our method preserves contour topology, in contrast to compression methods applied to the corresponding field function. We provide numerical results for scalar fields defined on planar domains. Our approach generalizes to volumetric domains, time-varying contours, and level sets of vector fields.

  14. Updating representations of temporal intervals.

    PubMed

    Danckert, James; Anderson, Britt

    2015-12-01

    Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings. PMID:26303026

  15. College Students' Perceptions toward the Multi Modal Representations and Instruction of Representations in Learning Modern Physics

    ERIC Educational Resources Information Center

    Yesildag Hasançebi, Funda; Günel, Murat

    2013-01-01

    Problem Statement: In recent years, researchers on learning have focused on learning with multimodal representation and this research has shown that when learners can interact with an appropriate representation their performance is enhanced. If students have the opportunity to interact consciously with modal representation, learning can be…

  16. Numerical Magnitude Representations Influence Arithmetic Learning

    ERIC Educational Resources Information Center

    Booth, Julie L.; Siegler, Robert S.

    2008-01-01

    This study examined whether the quality of first graders' (mean age = 7.2 years) numerical magnitude representations is correlated with, predictive of, and causally related to their arithmetic learning. The children's pretest numerical magnitude representations were found to be correlated with their pretest arithmetic knowledge and to be…

  17. Geometric Representations for Discrete Fourier Transforms

    NASA Technical Reports Server (NTRS)

    Cambell, C. W.

    1986-01-01

    Simple geometric representations show symmetry and periodicity of discrete Fourier transforms (DFT's). Help in visualizing requirements for storing and manipulating transform value in computations. Representations useful in any number of dimensions, but particularly in one-, two-, and three-dimensional cases often encountered in practice.

  18. Body-Specific Representations of Spatial Location

    ERIC Educational Resources Information Center

    Brunye, Tad T.; Gardony, Aaron; Mahoney, Caroline R.; Taylor, Holly A.

    2012-01-01

    The body specificity hypothesis (Casasanto, 2009) posits that the way in which people interact with the world affects their mental representation of information. For instance, right- versus left-handedness affects the mental representation of affective valence, with right-handers categorically associating good with rightward areas and bad with…

  19. Improving Representational Competence with Concrete Models

    ERIC Educational Resources Information Center

    Stieff, Mike; Scopelitis, Stephanie; Lira, Matthew E.; DeSutter, Dane

    2016-01-01

    Representational competence is a primary contributor to student learning in science, technology, engineering, and math (STEM) disciplines and an optimal target for instruction at all educational levels. We describe the design and implementation of a learning activity that uses concrete models to improve students' representational competence and…

  20. Identities, Social Representations and Critical Thinking

    ERIC Educational Resources Information Center

    Lopez-Facal, Ramon; Jimenez-Aleixandre, Maria Pilar

    2009-01-01

    This comment on L. Simonneaux and J. Simonneaux paper focuses on the role of "identities" in dealing with socio-scientific issues. We argue that there are two types of identities (social representations) influencing the students' positions: On the one hand their social representations of the bears' and wolves' identities as belonging to particular…

  1. Drawings as Representations of Children's Conceptions

    ERIC Educational Resources Information Center

    Ehrlen, Karin

    2009-01-01

    Drawings are often used to obtain an idea of children's conceptions. Doing so takes for granted an unambiguous relation between conceptions and their representations in drawings. This study was undertaken to gain knowledge of the relation between children's conceptions and their representation of these conceptions in drawings. A theory of…

  2. Characterizing Interaction with Visual Mathematical Representations

    ERIC Educational Resources Information Center

    Sedig, Kamran; Sumner, Mark

    2006-01-01

    This paper presents a characterization of computer-based interactions by which learners can explore and investigate visual mathematical representations (VMRs). VMRs (e.g., geometric structures, graphs, and diagrams) refer to graphical representations that visually encode properties and relationships of mathematical structures and concepts.…

  3. Representations of the Magnitudes of Fractions

    ERIC Educational Resources Information Center

    Schneider, Michael; Siegler, Robert S.

    2010-01-01

    We tested whether adults can use integrated, analog, magnitude representations to compare the values of fractions. The only previous study on this question concluded that even college students cannot form such representations and instead compare fraction magnitudes by representing numerators and denominators as separate whole numbers. However,…

  4. Transqueer Representations and How We Educate

    ERIC Educational Resources Information Center

    Siebler, Kay

    2010-01-01

    This article examines the representations of transqueers (specifically female to male transsexuals) in popular media and how these representations shape attitudes of transqueers both with those outside the LGBT community and those within the community. The article discusses how these cultural images of FTM transqueers imply that being accepted…

  5. School Board Election Structure and Democratic Representation

    ERIC Educational Resources Information Center

    Allen, Ann; Plank, David N.

    2005-01-01

    Policies governing the organization and timing of school elections affect democratic representation in school decision making. Some argue that school board elections should be consolidated with general municipal elections on the grounds that this will increase participation and representation, but little empirical work addresses the consequences…

  6. Representational Issues in Students Learning about Evaporation

    ERIC Educational Resources Information Center

    Tytler, Russell; Prain, Vaughan; Peterson, Suzanne

    2007-01-01

    This study draws on recent research on the central role of representation in learning. While there has been considerable research on students' understanding of evaporation, the representational issues entailed in this understanding have not been investigated in depth. The study explored students' engagement with evaporation phenomena through…

  7. Elementary School Students' Mental Representation of Fractions

    ERIC Educational Resources Information Center

    Pitta-Pantazi, Demetra; Gray, Eddie M.; Christou, Constantinos

    2004-01-01

    Based on psychological approaches that evoke mental representations through verbal and visual cues, this paper investigates the different kinds of mental representations projected by 8 to 11 year old children of identified arithmetical achievement when responding to verbal and visual stimuli associated with fractions. It examines how the visual…

  8. Representable states on quasilocal quasi *-algebras

    SciTech Connect

    Bagarello, F.; Trapani, C.; Triolo, S.

    2011-01-15

    Continuing a previous analysis originally motivated by physics, we consider representable states on quasilocal quasi *-algebras, starting with examining the possibility for a compatible family of local states to give rise to a global state. Some properties of local modifications of representable states and some aspects of their asymptotic behavior are also considered.

  9. Parts, Cavities, and Object Representation in Infancy

    ERIC Educational Resources Information Center

    Hayden, Angela; Bhatt, Ramesh S.; Kangas, Ashley; Zieber, Nicole

    2011-01-01

    Part representation is not only critical to object perception but also plays a key role in a number of basic visual cognition functions, such as figure-ground segregation, allocation of attention, and memory for shapes. Yet, virtually nothing is known about the development of part representation. If parts are fundamental components of object shape…

  10. Identifying Bilingual Semantic Neural Representations across Languages

    ERIC Educational Resources Information Center

    Buchweitz, Augusto; Shinkareva, Svetlana V.; Mason, Robert A.; Mitchell, Tom M.; Just, Marcel Adam

    2012-01-01

    The goal of the study was to identify the neural representation of a noun's meaning in one language based on the neural representation of that same noun in another language. Machine learning methods were used to train classifiers to identify which individual noun bilingual participants were thinking about in one language based solely on their…

  11. Elementary Teachers' Instructional Practices Involving Graphical Representations

    ERIC Educational Resources Information Center

    Coleman, Julianne

    2010-01-01

    The goal of this study was to gather data on US elementary school teachers' (K-5) instructional practices with graphical representations. The results revealed high percentages of usage for graphical representations but with varying levels of frequency. Overall, the most frequently reported instructional practices by teachers included 1) pointing…

  12. Self-Representation and Brain Development

    ERIC Educational Resources Information Center

    Lewis, Michael; Carmody, Dennis P.

    2008-01-01

    This study examined the relation between self-representation and brain development in infants and young children. Self-representation was assessed by mirror recognition, personal pronoun use, and pretend play. Structural brain images were obtained from magnetic resonance imaging (MRI). Brain development was assessed by a quantitative measure of…

  13. Sparse representation for the ISAR image reconstruction

    NASA Astrophysics Data System (ADS)

    Hu, Mengqi; Montalbo, John; Li, Shuxia; Sun, Ligang; Qiao, Zhijun G.

    2016-05-01

    In this paper, a sparse representation of the data for an inverse synthetic aperture radar (ISAR) system is provided in two dimensions. The proposed sparse representation motivates the use a of a Convex Optimization that recovers the image with far less samples, which is required by Nyquist-Shannon sampling theorem to increases the efficiency and decrease the cost of calculation in radar imaging.

  14. Efficient online bootstrapping of sensory representations.

    PubMed

    Gepperth, Alexander

    2013-05-01

    This is a simulation-based contribution exploring a novel approach to the open-ended formation of multimodal representations in autonomous agents. In particular, we address the issue of transferring ("bootstrapping") feature selectivities between two modalities, from a previously learned or innate reference representation to a new induced representation. We demonstrate the potential of this algorithm by several experiments with synthetic inputs modeled after a robotics scenario where multimodal object representations are "bootstrapped" from a (reference) representation of object affordances. We focus on typical challenges in autonomous agents: absence of human supervision, changing environment statistics and limited computing power. We propose an autonomous and local neural learning algorithm termed PROPRE (projection-prediction) that updates induced representations based on predictability: competitive advantages are given to those feature-sensitive elements that are inferable from activities in the reference representation. PROPRE implements a bi-directional interaction of clustering ("projection") and inference ("prediction"), the key ingredient being an efficient online measure of predictability controlling learning in the projection step. We show that the proposed method is computationally efficient and stable, and that the multimodal transfer of feature selectivity is successful and robust under resource constraints. Furthermore, we successfully demonstrate robustness to noisy reference representations, non-stationary input statistics and uninformative inputs. PMID:23266481

  15. The Decimal Representation of Real Numbers

    ERIC Educational Resources Information Center

    Kalapodi, A.

    2010-01-01

    The representation of natural numbers in decimal form is an unequivocal procedure while for the representation of real numbers some ambiguities concerning the existence of infinitely many digits equal to 9 still emerge. One of the most frequently confronted misunderstandings is whether 0.999...equals 1 or not, and if not what number does this…

  16. Media Representation of Teachers across Five Countries

    ERIC Educational Resources Information Center

    Alhamdan, Bandar; Al-Saadi, Khalid; Baroutsis, Aspa; Du Plessis, Anna; Hamid, Obaidul M.; Honan, Eileen

    2014-01-01

    This paper reports on an investigation into the representation of teachers in newspapers in five countries. An innovative methodology was used to develop a method of inquiry that supports a deeper understanding of media representations of teachers which can also be used by other researchers in comparative education. The paper explores relevant…

  17. 48 CFR 1480.803 - Representation process.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Representation process. 1480.803 Section 1480.803 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR INDIAN... Offeror 1480.803 Representation process. (a) Only IEEs may participate in acquisitions set aside...

  18. Generating Descriptions of Motion from Cognitive Representations

    ERIC Educational Resources Information Center

    Keil, Benjamin

    2010-01-01

    This dissertation presents a novel method of sentence generation, drawing on the insight from Cognitive Semantics (Talmy, 2000a,b) that the effect of uttering a sentence is to evoke a Cognitive Representation in the mind of the listener. Under the assumption that this Cognitive Representation is also present in the speaker and defines (part of)…

  19. The logical model for pattern representation

    NASA Astrophysics Data System (ADS)

    Telnarova, Zdenka; Schenk, Jiri

    2016-06-01

    Patterns are mentioned usually in the extraction context. Little stress is posed in their representation and management. This paper is focused on representation of the patterns, manipulation with patterns and query patterns. Crucial issue can be seen in systematic approach to pattern management and specific pattern query language which takes into consideration semantics of patterns..

  20. How Do Students Misunderstand Number Representations?

    ERIC Educational Resources Information Center

    Herman, Geoffrey L.; Zilles, Craig; Loui, Michael C.

    2011-01-01

    We used both student interviews and diagnostic testing to reveal students' misconceptions about number representations in computing systems. This article reveals that students who have passed an undergraduate level computer organization course still possess surprising misconceptions about positional notations, two's complement representation, and…

  1. 32 CFR 724.215 - Military representation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Military representation. 724.215 Section 724.215 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation....

  2. 32 CFR 724.215 - Military representation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Military representation. 724.215 Section 724.215 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation....

  3. 32 CFR 724.215 - Military representation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Military representation. 724.215 Section 724.215 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation....

  4. Information entrophy via Glauber's Q-representation

    NASA Technical Reports Server (NTRS)

    Keitel, C. H.; Wodkiewicz, K.

    1993-01-01

    We present a convenient way to evaluate the information entropy of a quantum mechanical state via the Glauber Q-representation. As an example we discuss the information entropy of a thermally relaxing squeezed state in terms of its Q-representation and show the validity of the corresponding entropic uncertainty- and Araki-Lieb inequalities.

  5. 10 CFR 60.65 - Representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Representation. 60.65 Section 60.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Participation by State Governments and Affected Indian Tribes § 60.65 Representation. Any person who acts...

  6. 10 CFR 60.65 - Representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Representation. 60.65 Section 60.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Participation by State Governments and Affected Indian Tribes § 60.65 Representation. Any person who acts...

  7. 10 CFR 60.65 - Representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Representation. 60.65 Section 60.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Participation by State Governments and Affected Indian Tribes § 60.65 Representation. Any person who acts...

  8. 10 CFR 60.65 - Representation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Representation. 60.65 Section 60.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Participation by State Governments and Affected Indian Tribes § 60.65 Representation. Any person who acts...

  9. 10 CFR 60.65 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Representation. 60.65 Section 60.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Participation by State Governments and Affected Indian Tribes § 60.65 Representation. Any person who acts...

  10. 32 CFR 724.215 - Military representation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Military representation. 724.215 Section 724.215 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation....

  11. 32 CFR 724.215 - Military representation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Military representation. 724.215 Section 724.215 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation....

  12. Representing Energy. II. Energy Tracking Representations

    ERIC Educational Resources Information Center

    Scherr, Rachel E.; Close, Hunter G.; Close, Eleanor W.; Vokos, Stamatis

    2012-01-01

    The Energy Project at Seattle Pacific University has developed representations that embody the substance metaphor and support learners in conserving and tracking energy as it flows from object to object and changes form. Such representations enable detailed modeling of energy dynamics in complex physical processes. We assess student learning by…

  13. Gifted Children's Representations of Learner Identities

    ERIC Educational Resources Information Center

    Porath, Marion; Lupart, Judy

    2009-01-01

    Elementary and secondary students identified as gifted produced representations of themselves as readers, writers, and mathematicians and were interviewed about what they chose to represent. Interviews indicated a developmental progression in the way academic learning is understood, a progression that also was evident in their representations.…

  14. Efficient image representations and features

    NASA Astrophysics Data System (ADS)

    Dorr, Michael; Vig, Eleonora; Barth, Erhardt

    2013-03-01

    Interdisciplinary research in human vision and electronic imaging has greatly contributed to the current state of the art in imaging technologies. Image compression and image quality are prominent examples and the progress made in these areas relies on a better understanding of what natural images are and how they are perceived by the human visual system. A key research question has been: given the (statistical) properties of natural images, what are the most efficient and perceptually relevant image representations, what are the most prominent and descriptive features of images and videos? We give an overview of how these topics have evolved over the 25 years of HVEI conferences and how they have influenced the current state of the art. There are a number of striking parallels between human vision and electronic imaging. The retina does lateral inhibition, one of the early coders was using a Laplacian pyramid; primary visual cortical areas have orientation- and frequency-selective neurons, the current JPEG standard defines similar wavelet transforms; the brain uses a sparse code, engineers are currently excited about sparse coding and compressed sensing. Some of this has indeed happened at the HVEI conferences and we would like to distill that.

  15. Continuum representations of cellular solids

    SciTech Connect

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  16. Representation of probabilistic scientific knowledge

    PubMed Central

    2013-01-01

    The theory of probability is widely used in biomedical research for data analysis and modelling. In previous work the probabilities of the research hypotheses have been recorded as experimental metadata. The ontology HELO is designed to support probabilistic reasoning, and provides semantic descriptors for reporting on research that involves operations with probabilities. HELO explicitly links research statements such as hypotheses, models, laws, conclusions, etc. to the associated probabilities of these statements being true. HELO enables the explicit semantic representation and accurate recording of probabilities in hypotheses, as well as the inference methods used to generate and update those hypotheses. We demonstrate the utility of HELO on three worked examples: changes in the probability of the hypothesis that sirtuins regulate human life span; changes in the probability of hypotheses about gene functions in the S. cerevisiae aromatic amino acid pathway; and the use of active learning in drug design (quantitative structure activity relation learning), where a strategy for the selection of compounds with the highest probability of improving on the best known compound was used. HELO is open source and available at https://github.com/larisa-soldatova/HELO PMID:23734675

  17. Phase space representation of quantum dynamics

    SciTech Connect

    Polkovnikov, Anatoli

    2010-08-15

    We discuss a phase space representation of quantum dynamics of systems with many degrees of freedom. This representation is based on a perturbative expansion in quantum fluctuations around one of the classical limits. We explicitly analyze expansions around three such limits: (i) corpuscular or Newtonian limit in the coordinate-momentum representation, (ii) wave or Gross-Pitaevskii limit for interacting bosons in the coherent state representation, and (iii) Bloch limit for the spin systems. We discuss both the semiclassical (truncated Wigner) approximation and further quantum corrections appearing in the form of either stochastic quantum jumps along the classical trajectories or the nonlinear response to such jumps. We also discuss how quantum jumps naturally emerge in the analysis of non-equal time correlation functions. This representation of quantum dynamics is closely related to the phase space methods based on the Wigner-Weyl quantization and to the Keldysh technique. We show how such concepts as the Wigner function, Weyl symbol, Moyal product, Bopp operators, and others automatically emerge from the Feynmann's path integral representation of the evolution in the Heisenberg representation. We illustrate the applicability of this expansion with various examples mostly in the context of cold atom systems including sine-Gordon model, one- and two-dimensional Bose-Hubbard model, Dicke model and others.

  18. Localization of Unitary Braid Group Representations

    NASA Astrophysics Data System (ADS)

    Rowell, Eric C.; Wang, Zhenghan

    2012-05-01

    Governed by locality, we explore a connection between unitary braid group representations associated to a unitary R-matrix and to a simple object in a unitary braided fusion category. Unitary R-matrices, namely unitary solutions to the Yang-Baxter equation, afford explicitly local unitary representations of braid groups. Inspired by topological quantum computation, we study whether or not it is possible to reassemble the irreducible summands appearing in the unitary braid group representations from a unitary braided fusion category with possibly different positive multiplicities to get representations that are uniformly equivalent to the ones from a unitary R-matrix. Such an equivalence will be called a localization of the unitary braid group representations. We show that the q = e π i/6 specialization of the unitary Jones representation of the braid groups can be localized by a unitary 9 × 9 R-matrix. Actually this Jones representation is the first one in a family of theories ( SO( N), 2) for an odd prime N > 1, which are conjectured to be localizable. We formulate several general conjectures and discuss possible connections to physics and computer science.

  19. Spatially variant morphological restoration and skeleton representation.

    PubMed

    Bouaynaya, Nidhal; Charif-Chefchaouni, Mohammed; Schonfeld, Dan

    2006-11-01

    The theory of spatially variant (SV) mathematical morphology is used to extend and analyze two important image processing applications: morphological image restoration and skeleton representation of binary images. For morphological image restoration, we propose the SV alternating sequential filters and SV median filters. We establish the relation of SV median filters to the basic SV morphological operators (i.e., SV erosions and SV dilations). For skeleton representation, we present a general framework for the SV morphological skeleton representation of binary images. We study the properties of the SV morphological skeleton representation and derive conditions for its invertibility. We also develop an algorithm for the implementation of the SV morphological skeleton representation of binary images. The latter algorithm is based on the optimal construction of the SV structuring element mapping designed to minimize the cardinality of the SV morphological skeleton representation. Experimental results show the dramatic improvement in the performance of the SV morphological restoration and SV morphological skeleton representation algorithms in comparison to their translation-invariant counterparts. PMID:17076415

  20. Knowledge representation techniques for seismic signal understanding

    SciTech Connect

    Not Available

    1986-03-01

    Seismic monitoring and discrimination of seismic events for purposes of nuclear test ban verification require the interpretation of large volumes of uncertain signal data by seismic experts. Several levels of knowledge representation are envisioned to make the transduction from raw signal data to the level of symbolic representation used to represent knowledge by AI techniques. At the lower level, techniques drawn from the feature based approach to speech recognition and syntactic pattern recognition address primitive features and segmentation into symbolic units of syntax which apply to various representations or transforms of the seismic signal, such as seismograms. At a higher level, conventional knowledge representation schemes and new algebraic approaches to knowledge representation based on algebraic systems are considered as they might apply to representations of the signal established by the lower level techniques. This report defines and outlines these techniques as well as describes how they are likely to be successfully integrated into a unified approach for representing knowledge in seismic signals for symbolic signal processing. The report also recommends further steps and directions the research should take and includes a preliminary bibliography covering both theoretical and applied aspects of the knowledge representation techniques discussed. (ACR)

  1. General Regression and Representation Model for Classification

    PubMed Central

    Qian, Jianjun; Yang, Jian; Xu, Yong

    2014-01-01

    Recently, the regularized coding-based classification methods (e.g. SRC and CRC) show a great potential for pattern classification. However, most existing coding methods assume that the representation residuals are uncorrelated. In real-world applications, this assumption does not hold. In this paper, we take account of the correlations of the representation residuals and develop a general regression and representation model (GRR) for classification. GRR not only has advantages of CRC, but also takes full use of the prior information (e.g. the correlations between representation residuals and representation coefficients) and the specific information (weight matrix of image pixels) to enhance the classification performance. GRR uses the generalized Tikhonov regularization and K Nearest Neighbors to learn the prior information from the training data. Meanwhile, the specific information is obtained by using an iterative algorithm to update the feature (or image pixel) weights of the test sample. With the proposed model as a platform, we design two classifiers: basic general regression and representation classifier (B-GRR) and robust general regression and representation classifier (R-GRR). The experimental results demonstrate the performance advantages of proposed methods over state-of-the-art algorithms. PMID:25531882

  2. Artistic Representation with Pulsed Holography

    NASA Astrophysics Data System (ADS)

    Ishii, S.

    2013-02-01

    This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.

  3. Students' Representational Fluency at University: A Cross-Sectional Measure of How Multiple Representations Are Used by Physics Students Using the Representational Fluency Survey

    ERIC Educational Resources Information Center

    Hill, Matthew; Sharma, Manjula Devi

    2015-01-01

    To succeed within scientific disciplines, using representations, including those based on words, graphs, equations, and diagrams, is important. Research indicates that the use of discipline specific representations (sometimes referred to as expert generated representations), as well as multi-representational use, is critical for problem solving…

  4. Associative memory - An optimum binary neuron representation

    NASA Technical Reports Server (NTRS)

    Awwal, A. A.; Karim, M. A.; Liu, H. K.

    1989-01-01

    Convergence mechanism of vectors in the Hopfield's neural network is studied in terms of both weights (i.e., inner products) and Hamming distance. It is shown that Hamming distance should not always be used in determining the convergence of vectors. Instead, weights (which in turn depend on the neuron representation) are found to play a more dominant role in the convergence mechanism. Consequently, a new binary neuron representation for associative memory is proposed. With the new neuron representation, the associative memory responds unambiguously to the partial input in retrieving the stored information.

  5. Death representation of caregivers in hospice.

    PubMed

    Andruccioli, Jessica; Russo, Maria Maffia; Bruschi, Angela; Pedrabissi, Luigi; Sarti, Donatella; Monterubbianesi, Maria Cristina; Rossi, Sabina; Rocconi, Sabina; Raffaeli, William

    2012-11-01

    In this study, we investigated caregiver's death representation in hospice. The results presented here are a further analysis of the data collected in our previous study, concerning the evaluation of the caregiver in hospice. The data analysis of 24 caregivers of patients hospitalized in Rimini Hospice (Italy) underlined that caregivers avoiding death representation of the patient admitted to hospice had fewer protective factors (52.3%) and more risk factors (47.7%) than caregivers nonavoiding (66.5% and 33.5%, respectively). Caregivers avoiding death representation, moreover, experienced a greater distress (58%) than those nonavoiding (42%). PMID:22241459

  6. Understanding as Integration of Heterogeneous Representations

    NASA Astrophysics Data System (ADS)

    Martínez, Sergio F.

    2014-03-01

    The search for understanding is a major aim of science. Traditionally, understanding has been undervalued in the philosophy of science because of its psychological underpinnings; nowadays, however, it is widely recognized that epistemology cannot be divorced from psychology as sharp as traditional epistemology required. This eliminates the main obstacle to give scientific understanding due attention in philosophy of science. My aim in this paper is to describe an account of scientific understanding as an emergent feature of our mastering of different (causal) explanatory frameworks that takes place through the mastering of scientific practices. Different practices lead to different kinds of representations. Such representations are often heterogeneous. The integration of such representations constitute understanding.

  7. Sparse representation of complex MRI images.

    PubMed

    Nandakumar, Hari Prasad; Ji, Jim

    2008-01-01

    Sparse representation of images acquired from Magnet Resonance Imaging (MRI) has several potential applications. MRI is unique in that the raw images are complex. Complex wavelet transforms (CWT) can be used to produce flexible signal representations when compared to Discrete Wavelet Transform (DWT). In this work, five different schemes using CWT or DWT are tested for sparse representation of MRI images which are in the form of complex values, separate real/imaginary, or separate magnitude/phase. The experimental results on real in-vivo MRI images show that appropriate CWT, e.g., dual-tree CWT (DTCWT), can achieve sparsity better than DWT with similar Mean Square Error. PMID:19162677

  8. Minimal representations, geometric quantization, and unitarity.

    PubMed Central

    Brylinski, R; Kostant, B

    1994-01-01

    In the framework of geometric quantization we explicitly construct, in a uniform fashion, a unitary minimal representation pio of every simply-connected real Lie group Go such that the maximal compact subgroup of Go has finite center and Go admits some minimal representation. We obtain algebraic and analytic results about pio. We give several results on the algebraic and symplectic geometry of the minimal nilpotent orbits and then "quantize" these results to obtain the corresponding representations. We assume (Lie Go)C is simple. PMID:11607478

  9. Sparse representation in speech signal processing

    NASA Astrophysics Data System (ADS)

    Lee, Te-Won; Jang, Gil-Jin; Kwon, Oh-Wook

    2003-11-01

    We review the sparse representation principle for processing speech signals. A transformation for encoding the speech signals is learned such that the resulting coefficients are as independent as possible. We use independent component analysis with an exponential prior to learn a statistical representation for speech signals. This representation leads to extremely sparse priors that can be used for encoding speech signals for a variety of purposes. We review applications of this method for speech feature extraction, automatic speech recognition and speaker identification. Furthermore, this method is also suited for tackling the difficult problem of separating two sounds given only a single microphone.

  10. On a categorial aspect of knowledge representation

    NASA Astrophysics Data System (ADS)

    Tataj, Emanuel; Mulawka, Jan; Nieznański, Edward

    Adequate representation of data is crucial for modeling any type of data. To faithfully present and describe the relevant section of the world it is necessary to select the method that can easily be implemented on a computer system which will help in further description allowing reasoning. The main objective of this contribution is to present methods of knowledge representation using categorial approach. Next to identify the main advantages for computer implementation. Categorical aspect of knowledge representation is considered in semantic networks realisation. Such method borrows already known metaphysics properties for data modeling process. The potential topics of further development of categorical semantic networks implementations are also underlined.

  11. Dispersive approaches for three-particle final state interaction

    DOE PAGESBeta

    Guo, Peng; Danilkin, Igor V.; Szczepaniak, Adam P.

    2015-10-30

    In this work, we presented different representations of Khuri-Treiman equation, the advantage and disadvantage of each representations are discussed. With a scattering amplitude toy model, we also studied the sensitivity of solution of KT equation to left-hand cut of toy model and to the different approximate methods. At last, we give a brief discussion of Watson's theorem when three particles in final states are involved.

  12. 16 CFR 322.3 - Prohibited representations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and relies upon competent and reliable evidence that substantiates that the representation is true. For the purposes of this paragraph, “competent and reliable evidence” means tests, analyses, research... accepted in the profession to yield accurate and reliable results....

  13. 16 CFR 322.3 - Prohibited representations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and relies upon competent and reliable evidence that substantiates that the representation is true. For the purposes of this paragraph, “competent and reliable evidence” means tests, analyses, research... accepted in the profession to yield accurate and reliable results....

  14. Identities, social representations and critical thinking

    NASA Astrophysics Data System (ADS)

    López-Facal, Ramón; Jiménez-Aleixandre, María Pilar

    2009-09-01

    This comment on L. Simonneaux and J. Simonneaux paper focuses on the role of identities in dealing with socio-scientific issues. We argue that there are two types of identities (social representations) influencing the students' positions: On the one hand their social representations of the bears' and wolves' identities as belonging to particular countries (Slovenia versus France for bears, France and Italy for wolves), in other words, as having national identities; on the other hand representations of their own identities as belonging to the field of agricultural practitioners, and so sharing this socio-professional identity with shepherds and breeders, as opposed to ecologists. We discuss how these representations of identities influenced students' reasoning and argumentation, blocking in some cases the evaluation of evidence. Implications for developing critical thinking and for dealing with SSI in the classrooms are outlined.

  15. 29 CFR 452.127 - Proportionate representation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the election provisions of the Act. Congress did not attempt to specify the organizational structure... delegates who have been chosen by secret ballot, the structure of representation of the membership is...

  16. 48 CFR 2009.570-4 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational Conflicts of Interest 2009.570-4 Representation... whether situations or relationships exist which may constitute organizational conflicts of interest with... criteria stated in the following paragraph (b) of this section. (b) The organizational conflicts...

  17. through the Use of Aesthetic Representations

    ERIC Educational Resources Information Center

    Crim, Courtney L.; Kennedy, Kimberley D.; Thornton, Jenifer S.

    2013-01-01

    multiple intelligences, and aesthetic representations. Next, it presents the methodology, reports findings, and discusses themes related to the authors' research questions. Finally, it concludes that tapping into students' multiple intelligence strength(s) is an…

  18. 2-Group Representations for Spin Foams

    SciTech Connect

    Baratin, Aristide; Wise, Derek K.

    2009-12-15

    Just as 3d state sum models, including 3d quantum gravity, can be built using categories of group representations, '2-categories of 2-group representations' may provide interesting state sum models for 4d quantum topology, if not quantum gravity. Here we focus on the 'Euclidean 2-group', built from the rotation group SO (4) and its action on the translation group R{sup 4} of Euclidean space. We explain its infinite-dimensional unitary representations, and construct a model based on the resulting representation 2-category. This model, with clear geometric content and explicit 'metric data' on triangulation edges, shows up naturally in an attempt to write the amplitudes of ordinary quantum field theory in a background independent way.

  19. Galois Representations Connected with Hyperbolic Curves

    NASA Astrophysics Data System (ADS)

    Voevodskiĭ, V. A.

    1992-06-01

    The author considers Galois group actions on the fundamental groups of curves of hyperbolic type, and proves certain cases of Grothendieck's conjecture about the possibility of recovering a curve from its Galois representation.

  20. Mental Representations Formed From Educational Website Formats

    SciTech Connect

    Elizabeth T. Cady; Kimberly R. Raddatz; Tuan Q. Tran; Bernardo de la Garza; Peter D. Elgin

    2006-10-01

    The increasing popularity of web-based distance education places high demand on distance educators to format web pages to facilitate learning. However, limited guidelines exist regarding appropriate writing styles for web-based distance education. This study investigated the effect of four different writing styles on reader’s mental representation of hypertext. Participants studied hypertext written in one of four web-writing styles (e.g., concise, scannable, objective, and combined) and were then administered a cued association task intended to measure their mental representations of the hypertext. It is hypothesized that the scannable and combined styles will bias readers to scan rather than elaborately read, which may result in less dense mental representations (as identified through Pathfinder analysis) relative to the objective and concise writing styles. Further, the use of more descriptors in the objective writing style will lead to better integration of ideas and more dense mental representations than the concise writing style.

  1. Students' understanding of molecular structure representations

    NASA Astrophysics Data System (ADS)

    Ferk, Vesna; Vrtacnik, Margareta; Blejec, Andrej; Gril, Alenka

    2003-10-01

    The purpose of the investigation was to determine the meanings attached by students to the different kinds of molecular structure representations used in chemistry teaching. The students (n = 124) were from primary (aged 13-14 years) and secondary (aged 17-18 years) schools and a university (aged 21-25 years). A computerised 'Chemical Visualisation Test' was developed and applied. The research indicates that students' appreciation of three-dimensional molecular structures differs according to the kind of representation used. The best results were achieved with the use of concrete, and pseudo-concrete types of representations (e.g. three-dimensional models, their photographs, computer-generated models). However, the use of more abstract types (e.g. schematic representations, stereochemical formula) was less effective. A correlation between students' results on the Chemical Visualisation Test and their educational level, spatial visualisation, and spatial relations skills was shown statistically, but no statistically significant gender differences were observed.

  2. Applied research in auditory data representation

    NASA Astrophysics Data System (ADS)

    Frysinger, Steve P.

    1990-08-01

    A class of data displays, characterized generally as Auditory Data Representation, is described and motivated. This type of data representation takes advantage of the tremendous pattern recognition capability of the human auditory channel. Audible displays offer an alternative means of conveying quantitative data to the analyst to facilitate information extraction, and are successfully used alone and in conjunction with visual displays. The Auditory Data Representation literature is reviewed, along with elements of the allied fields of investigation, Psychoacoustics and Musical Perception. A methodology for applied research in this field, based upon the well-developed discipline of psychophysics, is elaborated using a recent experiment as a case study. This method permits objective estimation of a data representation technique by comparing it to alternative displays for the pattern recognition task at hand. The psychophysical threshold of signal to noise level, for constant pattern recognition performance, is the measure of display effectiveness.

  3. Representation and perception of scenic layout.

    PubMed

    Sanocki, Thomas

    2003-08-01

    This paper presents a cognitive approach to on-line spatial perception within scenes. A theoretical framework is developed, based on the idea that experience with a scene can activate a complex representation of layout that facilitates subsequent processing of spatial relations within the scene. The representations integrate significant, relevant scenic information and are substantial in amount or extent. The representations are active across short periods of time and across changes in the retinal position of the image. These claims were supported in a series of experiments in which pictures of scenes (primes) facilitated subsequent spatial relations processing within the scenes. The prime-induced representations integrated object identity and layout, were broad in scope, involved both foreground and background information, and were effective across changes in image position. PMID:12852935

  4. Interactive information retrieval systems with minimalist representation

    SciTech Connect

    Domeshek, E.; Kedar, S.; Gordon, A.

    1996-12-31

    Almost any information you might want is becoming available on-line. The problem is how to find what you need. One strategy to improve access to existing information sources, is intelligent information agents - an approach based on extensive representation and inference. Another alternative is to simply concentrate on better information organization and indexing. Our systems use a form of conceptual indexing sensitive to users` task-specific information needs. We aim for minimalist representation, coding only select aspects of stored items. Rather than supporting reliable automated inference, the primary purpose of our representations is to provide sufficient discrimination and guidance to a user for a given domain and task. This paper argues, using case studies, that minimal representations can make strong contributions to the usefulness and usability of interactive information systems, while minimizing knowledge engineering effort. We demonstrate this approach in several broad spectrum applications including video retrieval and advisory systems.

  5. Division algebra representations of SO(4, 2)

    NASA Astrophysics Data System (ADS)

    Kincaid, Joshua; Dray, Tevian

    2014-08-01

    Representations of SO(4, 2) are constructed using 4×4 and 2×2 matrices with elements in ℍ' ⊗ ℂ and the known isomorphism between the conformal group and SO(4, 2) is written explicitly in terms of the 4×4 representation. The Clifford algebra structure of SO(4, 2) is briefly discussed in this language, as is its relationship to other groups of physical interest.

  6. One dimensional representations in quantum optics

    NASA Technical Reports Server (NTRS)

    Janszky, J.; Adam, P.; Foldesi, I.; Vinogradov, An. V.

    1993-01-01

    The possibility of representing the quantum states of a harmonic oscillator not on the whole alpha-plane but on its one dimensional manifolds is considered. It is shown that a simple Gaussian distribution along a straight line describes a quadrature squeezed state while a similar Gaussian distribution along a circle leads to the amplitude squeezed state. The connection between the one dimensional representations and the usual Glauber representation is discussed.

  7. Compact 2-D graphical representation of DNA

    NASA Astrophysics Data System (ADS)

    Randić, Milan; Vračko, Marjan; Zupan, Jure; Novič, Marjana

    2003-05-01

    We present a novel 2-D graphical representation for DNA sequences which has an important advantage over the existing graphical representations of DNA in being very compact. It is based on: (1) use of binary labels for the four nucleic acid bases, and (2) use of the 'worm' curve as template on which binary codes are placed. The approach is illustrated on DNA sequences of the first exon of human β-globin and gorilla β-globin.

  8. Properties of Artifact Representations for Evolutionary Design

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2004-01-01

    To achieve evolutionary design systems that scale to the levels achieved by man-made artifacts we can look to their characteristics of modularity, hierarchy and regularity to guide us. For this we focus on design representations, since they strongly determine the ability of evolutionary design systems to evolve artifacts with these characteristics. We identify three properties of design representations - combination, control-flow and abstraction - and discuss how they relate to hierarchy, modularity and regularity.

  9. Exploring the Structure of Spatial Representations.

    PubMed

    Madl, Tamas; Franklin, Stan; Chen, Ke; Trappl, Robert; Montaldi, Daniela

    2016-01-01

    It has been suggested that the map-like representations that support human spatial memory are fragmented into sub-maps with local reference frames, rather than being unitary and global. However, the principles underlying the structure of these 'cognitive maps' are not well understood. We propose that the structure of the representations of navigation space arises from clustering within individual psychological spaces, i.e. from a process that groups together objects that are close in these spaces. Building on the ideas of representational geometry and similarity-based representations in cognitive science, we formulate methods for learning dissimilarity functions (metrics) characterizing participants' psychological spaces. We show that these learned metrics, together with a probabilistic model of clustering based on the Bayesian cognition paradigm, allow prediction of participants' cognitive map structures in advance. Apart from insights into spatial representation learning in human cognition, these methods could facilitate novel computational tools capable of using human-like spatial concepts. We also compare several features influencing spatial memory structure, including spatial distance, visual similarity and functional similarity, and report strong correlations between these dimensions and the grouping probability in participants' spatial representations, providing further support for clustering in spatial memory. PMID:27347681

  10. Mental representation and motor imagery training

    PubMed Central

    Schack, Thomas; Essig, Kai; Frank, Cornelia; Koester, Dirk

    2014-01-01

    Research in sports, dance and rehabilitation has shown that basic action concepts (BACs) are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, the structural dimensional analysis of mental representation (SDA-M), to assess action-relevant representational structures that reflect the organization of BACs. The SDA-M reveals a strong relationship between cognitive representation and performance if complex actions are performed. We show how the SDA-M can improve motor imagery training and how it contributes to our understanding of coaching processes. The SDA-M capitalizes on the objective measurement of individual mental movement representations before training and the integration of these results into the motor imagery training. Such motor imagery training based on mental representations (MTMR) has been applied successfully in professional sports such as golf, volleyball, gymnastics, windsurfing, and recently in the rehabilitation of patients who have suffered a stroke. PMID:24904368

  11. Exploring the Structure of Spatial Representations

    PubMed Central

    Madl, Tamas; Franklin, Stan; Chen, Ke; Trappl, Robert; Montaldi, Daniela

    2016-01-01

    It has been suggested that the map-like representations that support human spatial memory are fragmented into sub-maps with local reference frames, rather than being unitary and global. However, the principles underlying the structure of these ‘cognitive maps’ are not well understood. We propose that the structure of the representations of navigation space arises from clustering within individual psychological spaces, i.e. from a process that groups together objects that are close in these spaces. Building on the ideas of representational geometry and similarity-based representations in cognitive science, we formulate methods for learning dissimilarity functions (metrics) characterizing participants’ psychological spaces. We show that these learned metrics, together with a probabilistic model of clustering based on the Bayesian cognition paradigm, allow prediction of participants’ cognitive map structures in advance. Apart from insights into spatial representation learning in human cognition, these methods could facilitate novel computational tools capable of using human-like spatial concepts. We also compare several features influencing spatial memory structure, including spatial distance, visual similarity and functional similarity, and report strong correlations between these dimensions and the grouping probability in participants’ spatial representations, providing further support for clustering in spatial memory. PMID:27347681

  12. Spinor representations of affine Lie algebras

    PubMed Central

    Frenkel, I. B.

    1980-01-01

    Let [unk] be an infinite-dimensional Kac-Moody Lie algebra of one of the types Dl+1(2), Bl(1), or Dl(1). These algebras are characterized by the property that an elimination of any endpoint of their Dynkin diagrams gives diagrams of types Bl or Dl of classical orthogonal Lie algebras. We construct two representations of a Lie algebra [unk], which we call spinor representations, following the analogy with the classical case. We obtain that every spinor representation is either irreducible or has two irreducible components. This provides us with an explicit construction of fundamental representations of [unk], two for the type Dl+1(2), three for Bl(1), and four for Dl(1). We note the profound connection of our construction with quantum field theory—in particular, with fermion fields. Comparing the character formulas of our representations with another construction of the fundamental representations of Kac-Moody Lie algebras of types Al(1), Dl(1), El(1), we obtain classical Jacobi identities and addition formulas for elliptic θ-functions. PMID:16592912

  13. Seismic-source representation for spall

    SciTech Connect

    Day, S.M.; McLaughlin, K.L.

    1990-11-21

    Spall may be a significant secondary source of seismic waves from underground explosions. The proper representation of spall as a seismic source is important for forward and inverse modeling of explosions for yield estimation and discrimination studies. We present a new derivation of a widely used point force representation for spall, which is based on a horizontal tension crack model. The derivation clarifies the relationship between point force and moment tensor representations of the tension crack. For wavelengths long compared with spall depth, the two representations are equivalent, and the moment tensor time history is proportional to the doubly integrated time history of the point force. Numerical experiments verify that, for regional seismic phases, this equivalence is valid for all frequencies for which the point-source (long wavelength) approximation is valid. Further analysis shows that the moment tensor and point force representations retain their validity for non-planar spall surfaces, provided that the average dip of the surface is small. The equivalency of the two representations implies that a singular inverse problem will result from attempts to infer simultaneously the spectra of both these source terms from seismic waveforms. If the spall moment tensor alone is estimated by inversion of waveform data, the inferred numerical values of its components will depend inversely upon the source depth which is assumed in the inversion formalism.

  14. The Representation and Parametrization of Orthogonal Matrices.

    PubMed

    Shepard, Ron; Brozell, Scott R; Gidofalvi, Gergely

    2015-07-16

    Four representations and parametrizations of orthogonal matrices Q ∈ R(m×n) in terms of the minimal number of essential parameters {φ} are discussed: the exponential representation, the Householder reflector representation, the Givens rotation representation, and the rational Cayley transform representation. Both square n = m and rectangular n < m situations are considered. Two separate kinds of parametrizations are considered: one in which the individual columns of Q are distinct, the Stiefel manifold, and the other in which only span(Q) is significant, the Grassmann manifold. The practical issues of numerical stability, continuity, and uniqueness are discussed. The computation of Q in terms of the essential parameters {φ}, and also the extraction of {φ} for a given Q are considered for all of the parametrizations. The transformation of gradient arrays between the Q and {φ} variables is discussed for all representations. It is our hope that developers of new methods will benefit from this comparative presentation of an important but rarely analyzed subject. PMID:25946418

  15. The Representation of Polysemy: MEG Evidence

    PubMed Central

    Pylkkänen, Liina; Llinás, Rodolfo; Murphy, Gregory L.

    2006-01-01

    Most words in natural language are polysemous; i.e., they can be used in more than one way. For example, paper can be used to refer to a substance made out of wood pulp or to a daily publication printed on that substance. Even though virtually every sentence contains polysemy, there is little agreement as to how polysemy is represented in the mental lexicon. Do different uses of polysemous words involve access to a single representation or do our minds store distinct representations for each different sense? Here we investigated priming between senses with a combination of behavioral and magnetoencephalographic (MEG) measures in order to test whether different senses of the same word involve identity or mere formal and semantic similarity. Our results show that polysemy effects are clearly distinct from similarity effects bilaterally. In the left hemisphere, sense-relatedness elicited shorter latencies of the M350 source, which has been hypothesized to index lexical activation. Concurrent activity in the right hemisphere, on the other hand, peaked later for sense-related than for unrelated target stimuli, suggesting competition between related senses. The obtained pattern of results supports models in which the representation of polysemy involves both representational identity and difference: Related senses connect to same abstract lexical representation, but are distinctly listed within that representation. PMID:16417686

  16. Mental representation and motor imagery training.

    PubMed

    Schack, Thomas; Essig, Kai; Frank, Cornelia; Koester, Dirk

    2014-01-01

    Research in sports, dance and rehabilitation has shown that basic action concepts (BACs) are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, the structural dimensional analysis of mental representation (SDA-M), to assess action-relevant representational structures that reflect the organization of BACs. The SDA-M reveals a strong relationship between cognitive representation and performance if complex actions are performed. We show how the SDA-M can improve motor imagery training and how it contributes to our understanding of coaching processes. The SDA-M capitalizes on the objective measurement of individual mental movement representations before training and the integration of these results into the motor imagery training. Such motor imagery training based on mental representations (MTMR) has been applied successfully in professional sports such as golf, volleyball, gymnastics, windsurfing, and recently in the rehabilitation of patients who have suffered a stroke. PMID:24904368

  17. The representation of polysemy: MEG evidence.

    PubMed

    Pylkkänen, Liina; Llinás, Rodolfo; Murphy, Gregory L

    2006-01-01

    Most words in natural language are polysemous, that is, they can be used in more than one way. For example, paper can be used to refer to a substance made out of wood pulp or to a daily publication printed on that substance. Although virtually every sentence contains polysemy, there is little agreement as to how polysemy is represented in the mental lexicon. Do different uses of polysemous words involve access to a single representation or do our minds store distinct representations for each different sense? Here we investigated priming between senses with a combination of behavioral and magnetoencephalographic measures in order to test whether different senses of the same word involve identity or mere formal and semantic similarity. Our results show that polysemy effects are clearly distinct from similarity effects bilaterally. In the left hemisphere, sense-relatedness elicited shorter latencies of the M350 source, which has been hypothesized to index lexical activation. Concurrent activity in the right hemisphere, on the other hand, peaked later for sense-related than for unrelated target stimuli, suggesting competition between related senses. The obtained pattern of results supports models in which the representation of polysemy involves both representational identity and difference: Related senses connect to same abstract lexical representation, but are distinctly listed within that representation. PMID:16417686

  18. Learning with Multiple Representations. Advances in Learning and Instruction Series.

    ERIC Educational Resources Information Center

    van Someren, Maarten W., Ed.; Reimann, Peter, Ed.; Boshuizen, Henny P. A., Ed.; de Jong, Ton, Ed.

    This book addresses questions of multiple representations in human reasoning and learning. Computational approaches to learning with multiple representations are introduced, and the role of multiple representations in teaching is discussed. The following chapters are included in Part I: Multiple Representations in Learning Concepts form Physics…

  19. The Development of Numerical Estimation: Evidence against a Representational Shift

    ERIC Educational Resources Information Center

    Barth, Hilary C.; Paladino, Annie M.

    2011-01-01

    How do our mental representations of number change over development? The dominant view holds that children (and adults) possess multiple representations of number, and that age and experience lead to a shift from greater reliance upon logarithmically organized number representations to greater reliance upon more accurate, linear representations.…

  20. Representations and uses of light distribution functions

    NASA Astrophysics Data System (ADS)

    Lalonde, Paul Albert

    1998-11-01

    At their lowest level, all rendering algorithms depend on models of local illumination to define the interplay of light with the surfaces being rendered. These models depend both on the representations of light scattering at a surface due to reflection and to an equal extent on the representation of light sources and light fields. Both emission and reflection have in common that they describe how light leaves a surface as a function of direction. Reflection also depends on an incident light direction. Emission can depend on the position on the light source We call the functions representing emission and reflection light distribution functions (LDF's). There are some difficulties to using measured light distribution functions. The data sets are very large-the size of the data grows with the fourth power of the sampling resolution. For example, a bidirectional reflectance distribution function (BRDF) sampled at five degrees angular resolution, which is arguably insufficient to capture highlights and other high frequency effects in the reflection, can easily require one and a half million samples. Once acquired this data requires some form of interpolation to use them. Any compression method used must be efficient, both in space and in the time required to evaluate the function at a point or over a range of points. This dissertation examines a wavelet representation of light distribution functions that addresses these issues. A data structure is presented that allows efficient reconstruction of LDFs for a given set of parameters, making the wavelet representation feasible for rendering tasks. Texture mapping methods that take advantage of our LDF representations are examined, as well as techniques for filtering LDFs, and methods for using wavelet compressed bidirection reflectance distribution functions (BRDFs) and light sources with Monte Carlo path tracing algorithms. The wavelet representation effectively compresses BRDF and emission data while inducing only a

  1. A-Optimal Projection for Image Representation.

    PubMed

    He, Xiaofei; Zhang, Chiyuan; Zhang, Lijun; Li, Xuelong

    2016-05-01

    We consider the problem of image representation from the perspective of statistical design. Recent studies have shown that images are possibly sampled from a low dimensional manifold despite of the fact that the ambient space is usually very high dimensional. Learning low dimensional image representations is crucial for many image processing tasks such as recognition and retrieval. Most of the existing approaches for learning low dimensional representations, such as principal component analysis (PCA) and locality preserving projections (LPP), aim at discovering the geometrical or discriminant structures in the data. In this paper, we take a different perspective from statistical experimental design, and propose a novel dimensionality reduction algorithm called A-Optimal Projection (AOP). AOP is based on a linear regression model. Specifically, AOP finds the optimal basis functions so that the expected prediction error of the regression model can be minimized if the new representations are used for training the model. Experimental results suggest that the proposed approach provides a better representation and achieves higher accuracy in image retrieval. PMID:26353361

  2. Biologically Plausible, Human-Scale Knowledge Representation.

    PubMed

    Crawford, Eric; Gingerich, Matthew; Eliasmith, Chris

    2016-05-01

    Several approaches to implementing symbol-like representations in neurally plausible models have been proposed. These approaches include binding through synchrony (Shastri & Ajjanagadde, ), "mesh" binding (van der Velde & de Kamps, ), and conjunctive binding (Smolensky, ). Recent theoretical work has suggested that most of these methods will not scale well, that is, that they cannot encode structured representations using any of the tens of thousands of terms in the adult lexicon without making implausible resource assumptions. Here, we empirically demonstrate that the biologically plausible structured representations employed in the Semantic Pointer Architecture (SPA) approach to modeling cognition (Eliasmith, ) do scale appropriately. Specifically, we construct a spiking neural network of about 2.5 million neurons that employs semantic pointers to successfully encode and decode the main lexical relations in WordNet, which has over 100,000 terms. In addition, we show that the same representations can be employed to construct recursively structured sentences consisting of arbitrary WordNet concepts, while preserving the original lexical structure. We argue that these results suggest that semantic pointers are uniquely well-suited to providing a biologically plausible account of the structured representations that underwrite human cognition. PMID:26173464

  3. Action simulation: time course and representational mechanisms

    PubMed Central

    Springer, Anne; Parkinson, Jim; Prinz, Wolfgang

    2013-01-01

    The notion of action simulation refers to the ability to re-enact foreign actions (i.e., actions observed in other individuals). Simulating others' actions implies a mirroring of their activities, based on one's own sensorimotor competencies. Here, we discuss theoretical and experimental approaches to action simulation and the study of its representational underpinnings. One focus of our discussion is on the timing of internal simulation and its relation to the timing of external action, and a paradigm that requires participants to predict the future course of actions that are temporarily occluded from view. We address transitions between perceptual mechanisms (referring to action representation before and after occlusion) and simulation mechanisms (referring to action representation during occlusion). Findings suggest that action simulation runs in real-time; acting on newly created action representations rather than relying on continuous visual extrapolations. A further focus of our discussion pertains to the functional characteristics of the mechanisms involved in predicting other people's actions. We propose that two processes are engaged, dynamic updating and static matching, which may draw on both semantic and motor information. In a concluding section, we discuss these findings in the context of broader theoretical issues related to action and event representation, arguing that a detailed functional analysis of action simulation in cognitive, neural, and computational terms may help to further advance our understanding of action cognition and motor control. PMID:23847563

  4. Negation in the brain: modulating action representations.

    PubMed

    Tettamanti, Marco; Manenti, Rosa; Della Rosa, Pasquale A; Falini, Andrea; Perani, Daniela; Cappa, Stefano F; Moro, Andrea

    2008-11-01

    Sentential negation is a universal syntactic feature of human languages that reverses the truth value expressed by a sentence. An intriguing question concerns what brain mechanisms underlie our ability to represent and understand the meaning of negative sentences. We approach this issue by investigating action-related language processing and the associated neural representations. Using functional magnetic resonance imaging we measured brain activity in 18 healthy subjects during passive listening of sentences characterized by a factorial combination of polarity (affirmative vs. negative) and concreteness (action-related vs. abstract). Negation deactivated cortical areas and the left pallidum. Compared to abstract sentences, action-related sentences activated the left-hemispheric action-representation system. Crucially, the polarity by concreteness interactions showed that the activity within the action-representation system was specifically reduced for negative action-related vs. affirmative action-related sentences (compared to abstract sentences). Accordingly, functional integration within this system as measured by Dynamic Causal Modeling was specifically weaker for negative action-related than for affirmative action-related sentences. This modulation of action representations indicates that sentential negation transiently reduces the access to mental representations of the negated information. PMID:18771737

  5. In defense of abstract conceptual representations.

    PubMed

    Binder, Jeffrey R

    2016-08-01

    An extensive program of research in the past 2 decades has focused on the role of modal sensory, motor, and affective brain systems in storing and retrieving concept knowledge. This focus has led in some circles to an underestimation of the need for more abstract, supramodal conceptual representations in semantic cognition. Evidence for supramodal processing comes from neuroimaging work documenting a large, well-defined cortical network that responds to meaningful stimuli regardless of modal content. The nodes in this network correspond to high-level "convergence zones" that receive broadly crossmodal input and presumably process crossmodal conjunctions. It is proposed that highly conjunctive representations are needed for several critical functions, including capturing conceptual similarity structure, enabling thematic associative relationships independent of conceptual similarity, and providing efficient "chunking" of concept representations for a range of higher order tasks that require concepts to be configured as situations. These hypothesized functions account for a wide range of neuroimaging results showing modulation of the supramodal convergence zone network by associative strength, lexicality, familiarity, imageability, frequency, and semantic compositionality. The evidence supports a hierarchical model of knowledge representation in which modal systems provide a mechanism for concept acquisition and serve to ground individual concepts in external reality, whereas broadly conjunctive, supramodal representations play an equally important role in concept association and situation knowledge. PMID:27294428

  6. Asymmetric translation between multiple representations in chemistry

    NASA Astrophysics Data System (ADS)

    Lin, Yulan I.; Son, Ji Y.; Rudd, James A., II

    2016-03-01

    Experts are more proficient in manipulating and translating between multiple representations (MRs) of a given concept than novices. Studies have shown that instruction using MR can increase student understanding of MR, and one model for MR instruction in chemistry is the chemistry triplet proposed by Johnstone. Concreteness fading theory suggests that presenting concrete representations before abstract representations can increase the effectiveness of MR instruction; however, little work has been conducted on varying the order of different representations during instruction and the role of concreteness in assessment. In this study, we investigated the application of concreteness fading to MR instruction and assessment in teaching chemistry. In two experiments, undergraduate students in either introductory psychology courses or general chemistry courses were given MR instruction on phase changes using different orders of presentation and MR assessment questions based on the representations in the chemistry triplet. Our findings indicate that the order of presentation based on levels of concreteness in MR chemistry instruction is less important than implementation of comprehensive MR assessments. Even after MR instruction, students display an asymmetric understanding of the chemical phenomenon on the MR assessments. Greater emphasis on MR assessments may be an important component in MR instruction that effectively moves novices toward more expert MR understanding.

  7. Natural geometric representation for electron local observables

    SciTech Connect

    Minogin, V.G.

    2014-03-15

    An existence of the quartic identities for the electron local observables that define orthogonality relations for the 3D quantities quadratic in the electron observables is found. It is shown that the joint solution of the quartic and bilinear identities for the electron observables defines a unique natural representation of the observables. In the natural representation the vector type electron local observables have well-defined fixed positions with respect to a local 3D orthogonal reference frame. It is shown that the natural representation of the electron local observables can be defined in six different forms depending on a choice of the orthogonal unit vectors. The natural representation is used to determine the functional dependence of the electron wave functions on the local observables valid for any shape of the electron wave packet. -- Highlights: •Quartic identities that define the orthogonality relations for the electron local observables are found. •Joint solution of quartic and bilinear identities defines a unique natural representation of the electron local observables. •Functional dependence of the electron wave functions on the electron local observables is determined.

  8. The interaction of representation and reasoning

    PubMed Central

    Bundy, Alan

    2013-01-01

    Automated reasoning is an enabling technology for many applications of informatics. These applications include verifying that a computer program meets its specification; enabling a robot to form a plan to achieve a task and answering questions by combining information from diverse sources, e.g. on the Internet, etc. How is automated reasoning possible? Firstly, knowledge of a domain must be stored in a computer, usually in the form of logical formulae. This knowledge might, for instance, have been entered manually, retrieved from the Internet or perceived in the environment via sensors, such as cameras. Secondly, rules of inference are applied to old knowledge to derive new knowledge. Automated reasoning techniques have been adapted from logic, a branch of mathematics that was originally designed to formalize the reasoning of humans, especially mathematicians. My special interest is in the way that representation and reasoning interact. Successful reasoning is dependent on appropriate representation of both knowledge and successful methods of reasoning. Failures of reasoning can suggest changes of representation. This process of representational change can also be automated. We will illustrate the automation of representational change by drawing on recent work in my research group. PMID:24062623

  9. Unifying Geometrical Representations of Gauge Theory

    NASA Astrophysics Data System (ADS)

    Alsid, Scott; Serna, Mario

    2015-01-01

    We unify three approaches within the vast body of gauge-theory research that have independently developed distinct representations of a geometrical surface-like structure underlying the vector-potential. The three approaches that we unify are: those who use the compactified dimensions of Kaluza-Klein theory, those who use Grassmannian models (also called gauge theory embedding or models) to represent gauge fields, and those who use a hidden spatial metric to replace the gauge fields. In this paper we identify a correspondence between the geometrical representations of the three schools. Each school was mostly independently developed, does not compete with other schools, and attempts to isolate the gauge-invariant geometrical surface-like structures that are responsible for the resulting physics. By providing a mapping between geometrical representations, we hope physicists can now isolate representation-dependent physics from gauge-invariant physical results and share results between each school. We provide visual examples of the geometrical relationships between each school for electric and magnetic fields. We highlight a first new result: in all three representations a static electric field (electric field from a fixed ring of charge or a sphere of charge) has a hidden gauge-invariant time dependent surface that is underlying the vector potential.

  10. Learning through Constructing Representations in Science: A Framework of Representational Construction Affordances

    ERIC Educational Resources Information Center

    Prain, Vaughan; Tytler, Russell

    2012-01-01

    Compared with research on the role of student engagement with expert representations in learning science, investigation of the use and theoretical justification of student-generated representations to learn science is less common. In this paper, we present a framework that aims to integrate three perspectives to explain how and why…

  11. Disponibilite sociale des representations: approche linguistique (Social Availability and Representations: Linguistic Approach).

    ERIC Educational Resources Information Center

    Gajo, Laurent

    2000-01-01

    This article uses linguistic tools to analyze the social dimension of representations. The dynamics of social representations are viewed as the result of two processes: preconstruction and co-construction. More precisely, the notions of "social availability" and "reference-O" are developed and applied in a conversational analysis perspective. The…

  12. Traitement discursif et conversationnel des representations sociales (Discourse and Conversational Analysis of Social Representations).

    ERIC Educational Resources Information Center

    Serra, Cecilia

    2000-01-01

    This article examines the interpretive process of social representations of bilingualism by means of discourse and conversational analysis. Representations are to be understood as an interpretive set of assumptions conveyed by discourse, creating recurrent and habitual systems of dispositions and expectations. The article shows how discourse is…

  13. Probing Lexical Representations: Simultaneous Modeling of Word and Reader Contributions to Multidimensional Lexical Representations

    ERIC Educational Resources Information Center

    Goodwin, Amanda P.; Gilbert, Jennifer K.; Cho, Sun-Joo; Kearns, Devin M.

    2014-01-01

    The current study models reader, item, and word contributions to the lexical representations of 39 morphologically complex words for 172 middle school students using a crossed random-effects item response model with multiple outcomes. We report 3 findings. First, results suggest that lexical representations can be characterized by separate but…

  14. Development of the Bonding Representations Inventory to Identify Student Misconceptions about Covalent and Ionic Bonding Representations

    ERIC Educational Resources Information Center

    Luxford, Cynthia J.; Bretz, Stacey Lowery

    2014-01-01

    Teachers use multiple representations to communicate the concepts of bonding, including Lewis structures, formulas, space-filling models, and 3D manipulatives. As students learn to interpret these multiple representations, they may develop misconceptions that can create problems in further learning of chemistry. Interviews were conducted with 28…

  15. Argumentation-Based Collaborative Inquiry in Science through Representational Work: Impact on Primary Students' Representational Fluency

    ERIC Educational Resources Information Center

    Nichols, Kim; Gillies, Robyn; Hedberg, John

    2016-01-01

    This study explored the impact of argumentation-promoting collaborative inquiry and representational work in science on primary students' representational fluency. Two hundred sixty-six year 6 students received instruction on natural disasters with a focus on collaborative inquiry. Students in the Comparison condition received only this…

  16. Representations of the POINCARÉ Group from Positive Energy Representations of SO(2,3)

    NASA Astrophysics Data System (ADS)

    Moylan, P.

    2004-10-01

    We describe representations of the simply connected covering group of the Poincaré group, {˜ {B}}, which are associated with certain positive energy representations of SO0(2, 3), the simply connected cover of SO0(2, 3). The translation generators of these representations of {˜ {B}} can be viewed as solutions of certain algebraic equations with coefficients from a commutative algebraic extension of the skew field of {˜ {B}}. These representations of {˜ {B}} depend upon a parameter λ that is essentially the reciprocal of the radius of anti-deSitter space, and they go over into the Segal-Inönü-Wigner contractions of the corresponding representations of SO0(2, 3) as λ → 0. Explicit results are given for the Di and Rac representations and the representations of SO0(2, 3) which extend to massless, unitary irreducible representations of SU(2, 2), the four-fold cover of the conformal group of Minkowski space-time.

  17. On 2D graphical representation of DNA sequence of nondegeneracy

    NASA Astrophysics Data System (ADS)

    Zhang, Yusen; Liao, Bo; Ding, Kequan

    2005-08-01

    Some two-dimensional (2D) graphical representations of DNA sequences have been given by Gates, Nandy, Leong and Mogenthaler, Randić, and Liao et al., which give visual characterizations of DNA sequences. In this Letter, we introduce a nondegeneracy 2D graphical representation of DNA sequence, which is different from Randić's novel 2D representation and Liao's 2D representation. We also present the nondegeneracy forms corresponding to the representations of Gates, Nandy, Leong and Mogenthaler.

  18. Representational Competence in Chemistry: A Comparison between Students with Different Levels of Understanding of Basic Chemical Concepts and Chemical Representations

    ERIC Educational Resources Information Center

    Sim, Joong Hiong; Daniel, Esther Gnanamalar Sarojini

    2014-01-01

    Representational competence is defined as "skills in interpreting and using representations". This study attempted to compare students' of high, medium, and low levels of understanding of (1) basic chemical concepts, and (2) chemical representations, in their representational competence. A total of 411 Form 4 science students (mean age =…

  19. Functional representation for fermionic quantum fields

    NASA Astrophysics Data System (ADS)

    Floreanini, R.; Jackiw, R.

    1988-04-01

    A functional representation for fermionic quantum fields is developed in analogy to familiar results for bosonic fields. The infinite Clifford algebra of the field anticommutator is realized reducibly on a Grassmann functional space. On this space, transformation groups may be represented without normal ordering with respect to a Fock vacuum, and a projective representation for the two-dimensional conformal group is found, which is compared to the corresponding representation in terms of bosonic fields. When a quadratic Hamiltonian for the Fermi fields is posited, a Fock space can be constructed after a prescription for filling the Dirac sea is selected. Different filling prescriptions lead to inequivalent Fock spaces within the functional space. Explicit eigenfunctionals exhibit the peculiarities of fermionic field theory, such as fractional charge, Berry's phase, and anomalies.

  20. Cognitive and artificial representations in handwriting recognition

    NASA Astrophysics Data System (ADS)

    Lenaghan, Andrew P.; Malyan, Ron

    1996-03-01

    Both cognitive processes and artificial recognition systems may be characterized by the forms of representation they build and manipulate. This paper looks at how handwriting is represented in current recognition systems and the psychological evidence for its representation in the cognitive processes responsible for reading. Empirical psychological work on feature extraction in early visual processing is surveyed to show that a sound psychological basis for feature extraction exists and to describe the features this approach leads to. The first stage of the development of an architecture for a handwriting recognition system which has been strongly influenced by the psychological evidence for the cognitive processes and representations used in early visual processing, is reported. This architecture builds a number of parallel low level feature maps from raw data. These feature maps are thresholded and a region labeling algorithm is used to generate sets of features. Fuzzy logic is used to quantify the uncertainty in the presence of individual features.

  1. Quantum measurement in coherence-vector representation

    NASA Astrophysics Data System (ADS)

    Zhou, Tao

    2016-04-01

    We consider the quantum measurements on a finite quantum system in coherence-vector representation. In this representation, all the density operators of an N-level ( N ⩾ 2) quantum system constitute a convex set M (N) embedded in an ( N 2 - 1)-dimensional Euclidean space R^{N^2 - 1}, and we find that an orthogonal measurement is an ( N - 1)-dimensional projector operator on R^{N^2 - 1}. The states unchanged by an orthogonal measurement form an ( N - 1)-dimensional simplex, and in the case when N is prime or power of prime, the space of the density operator is a direct sum of ( N + 1) such simplices. The mathematical description of quantum measurement is plain in this representation, and this may have further applications in quantum information processing.

  2. Configuration space representation in parallel coordinates

    NASA Technical Reports Server (NTRS)

    Fiorini, Paolo; Inselberg, Alfred

    1989-01-01

    By means of a system of parallel coordinates, a nonprojective mapping from R exp N to R squared is obtained for any positive integer N. In this way multivariate data and relations can be represented in the Euclidean plane (embedded in the projective plane). Basically, R squared with Cartesian coordinates is augmented by N parallel axes, one for each variable. The N joint variables of a robotic device can be represented graphically by using parallel coordinates. It is pointed out that some properties of the relation are better perceived visually from the parallel coordinate representation, and that new algorithms and data structures can be obtained from this representation. The main features of parallel coordinates are described, and an example is presented of their use for configuration space representation of a mechanical arm (where Cartesian coordinates cannot be used).

  3. Knowledge representation in space flight operations

    NASA Technical Reports Server (NTRS)

    Busse, Carl

    1989-01-01

    In space flight operations rapid understanding of the state of the space vehicle is essential. Representation of knowledge depicting space vehicle status in a dynamic environment presents a difficult challenge. The NASA Jet Propulsion Laboratory has pursued areas of technology associated with the advancement of spacecraft operations environment. This has led to the development of several advanced mission systems which incorporate enhanced graphics capabilities. These systems include: (1) Spacecraft Health Automated Reasoning Prototype (SHARP); (2) Spacecraft Monitoring Environment (SME); (3) Electrical Power Data Monitor (EPDM); (4) Generic Payload Operations Control Center (GPOCC); and (5) Telemetry System Monitor Prototype (TSM). Knowledge representation in these systems provides a direct representation of the intrinsic images associated with the instrument and satellite telemetry and telecommunications systems. The man-machine interface includes easily interpreted contextual graphic displays. These interactive video displays contain multiple display screens with pop-up windows and intelligent, high resolution graphics linked through context and mouse-sensitive icons and text.

  4. Local-time representation of path integrals

    NASA Astrophysics Data System (ADS)

    Jizba, Petr; Zatloukal, Václav

    2015-12-01

    We derive a local-time path-integral representation for a generic one-dimensional time-independent system. In particular, we show how to rephrase the matrix elements of the Bloch density matrix as a path integral over x -dependent local-time profiles. The latter quantify the time that the sample paths x (t ) in the Feynman path integral spend in the vicinity of an arbitrary point x . Generalization of the local-time representation that includes arbitrary functionals of the local time is also provided. We argue that the results obtained represent a powerful alternative to the traditional Feynman-Kac formula, particularly in the high- and low-temperature regimes. To illustrate this point, we apply our local-time representation to analyze the asymptotic behavior of the Bloch density matrix at low temperatures. Further salient issues, such as connections with the Sturm-Liouville theory and the Rayleigh-Ritz variational principle, are also discussed.

  5. Cusped Wilson lines in symmetric representations

    NASA Astrophysics Data System (ADS)

    Correa, Diego H.; Massolo, Fidel I. Schaposnik; Trancanelli, Diego

    2015-08-01

    We study the cusped Wilson line operators and Bremsstrahlung functions associated to particles transforming in the rank- k symmetric representation of the gauge group U( N) for super Yang-Mills. We find the holographic D3-brane description for Wilson loops with internal cusps in two different limits: small cusp angle and . This allows for a non-trivial check of a conjectured relation between the Bremsstrahlung function and the expectation value of the 1/2 BPS circular loop in the case of a representation other than the fundamental. Moreover, we observe that in the limit of k ≫ N, the cusped Wilson line expectation value is simply given by the exponential of the 1-loop diagram. Using group theory arguments, this eikonal exponentiation is conjectured to take place for all Wilson loop operators in symmetric representations with large k, independently of the contour on which they are supported.

  6. Dissimilarity representations in lung parenchyma classification

    NASA Astrophysics Data System (ADS)

    Sørensen, Lauge; de Bruijne, Marleen

    2009-02-01

    A good problem representation is important for a pattern recognition system to be successful. The traditional approach to statistical pattern recognition is feature representation. More specifically, objects are represented by a number of features in a feature vector space, and classifiers are built in this representation. This is also the general trend in lung parenchyma classification in computed tomography (CT) images, where the features often are measures on feature histograms. Instead, we propose to build normal density based classifiers in dissimilarity representations for lung parenchyma classification. This allows for the classifiers to work on dissimilarities between objects, which might be a more natural way of representing lung parenchyma. In this context, dissimilarity is defined between CT regions of interest (ROI)s. ROIs are represented by their CT attenuation histogram and ROI dissimilarity is defined as a histogram dissimilarity measure between the attenuation histograms. In this setting, the full histograms are utilized according to the chosen histogram dissimilarity measure. We apply this idea to classification of different emphysema patterns as well as normal, healthy tissue. Two dissimilarity representation approaches as well as different histogram dissimilarity measures are considered. The approaches are evaluated on a set of 168 CT ROIs using normal density based classifiers all showing good performance. Compared to using histogram dissimilarity directly as distance in a emph{k} nearest neighbor classifier, which achieves a classification accuracy of 92.9%, the best dissimilarity representation based classifier is significantly better with a classification accuracy of 97.0% (text{emph{p" border="0" class="imgtopleft"> = 0.046).

  7. Context representation and fusion: advancements and opportunities.

    PubMed

    Khattak, Asad Masood; Akbar, Noman; Aazam, Mohammad; Ali, Taqdir; Khan, Adil Mehmood; Jeon, Seokhee; Hwang, Myunggwon; Lee, Sungyoung

    2014-01-01

    The acceptance and usability of context-aware systems have given them the edge of wide use in various domains and has also attracted the attention of researchers in the area of context-aware computing. Making user context information available to such systems is the center of attention. However, there is very little emphasis given to the process of context representation and context fusion which are integral parts of context-aware systems. Context representation and fusion facilitate in recognizing the dependency/relationship of one data source on another to extract a better understanding of user context. The problem is more critical when data is emerging from heterogeneous sources of diverse nature like sensors, user profiles, and social interactions and also at different timestamps. Both the processes of context representation and fusion are followed in one way or another; however, they are not discussed explicitly for the realization of context-aware systems. In other words most of the context-aware systems underestimate the importance context representation and fusion. This research has explicitly focused on the importance of both the processes of context representation and fusion and has streamlined their existence in the overall architecture of context-aware systems' design and development. Various applications of context representation and fusion in context-aware systems are also highlighted in this research. A detailed review on both the processes is provided in this research with their applications. Future research directions (challenges) are also highlighted which needs proper attention for the purpose of achieving the goal of realizing context-aware systems. PMID:24887042

  8. Context Representation and Fusion: Advancements and Opportunities

    PubMed Central

    Khattak, Asad Masood; Akbar, Noman; Aazam, Mohammad; Ali, Taqdir; Khan, Adil Mehmood; Jeon, Seokhee; Hwang, Myunggwon; Lee, Sungyoung

    2014-01-01

    The acceptance and usability of context-aware systems have given them the edge of wide use in various domains and has also attracted the attention of researchers in the area of context-aware computing. Making user context information available to such systems is the center of attention. However, there is very little emphasis given to the process of context representation and context fusion which are integral parts of context-aware systems. Context representation and fusion facilitate in recognizing the dependency/relationship of one data source on another to extract a better understanding of user context. The problem is more critical when data is emerging from heterogeneous sources of diverse nature like sensors, user profiles, and social interactions and also at different timestamps. Both the processes of context representation and fusion are followed in one way or another; however, they are not discussed explicitly for the realization of context-aware systems. In other words most of the context-aware systems underestimate the importance context representation and fusion. This research has explicitly focused on the importance of both the processes of context representation and fusion and has streamlined their existence in the overall architecture of context-aware systems’ design and development. Various applications of context representation and fusion in context-aware systems are also highlighted in this research. A detailed review on both the processes is provided in this research with their applications. Future research directions (challenges) are also highlighted which needs proper attention for the purpose of achieving the goal of realizing context-aware systems. PMID:24887042

  9. The string tension of SU(3) representations

    NASA Astrophysics Data System (ADS)

    Deldar, Sedigheh

    In this thesis, I study the theory of confinement by measuring the potentials and in particular the string tension, between static sources in a background of gluons in pure gauge SU(3). The potentials between static sources in a variety of representations (fundamental, 8, 6, 15-antisymmetric, 10, 27 and 15- symmetric) have been computed by measuring Wilson loops. Wilson loops for higher representations have been measured in terms of Wilson loops of the fundamental representation. The string tensions have been computed from fitting the potentials to a Coloumbic plus a linear term. The simulations have been done primarily on anisotropic lattices, using a O(a2) tadpole improved action. A range of lattice spacings (0.43 fm, 0.25 fm and 0.11 fm) and volumes (83 × 24, 103 × 24, 163 × 24 and 183 × 24) has been used to extrapolate to the continuum and to control finite volume effects. In addition, a simulation at a single lattice spacing has been performed on an isotropic (84) lattice. The potentials between static sources in various representations in SU(3) have also been calculated based on the fat-center-vortices model. At intermediate distances, the results from both the numerical and model calculations are in qualitative agreement with ``Casimir scaling,'' which says that the string tension is proportional to the quadratic operator of the representation. For large distances (as large as 2.4 fm) no color screening or change of the potential slope has been observed from the lattice calculations of this work. However, from the fat-center- vortices model, screening and change of the potential slope is seen for zero triality and non-zero triality representations, respectively.

  10. Evaluating illness representations in heart transplant patients.

    PubMed

    Janelle, Caroline; O'Connor, Kieron; Dupuis, Gilles

    2016-09-01

    The aim was to see whether qualitative analysis improved quantitative measurement of illness perception after heart transplant. Two methods of evaluating illness representations were compared: one quantitative (administration of the Illness Perception Questionnaire-Revised) and one qualitative (phenomenological reduction). The qualitative analysis provided greater insight into the idiosyncratic and dynamic nature of the concept of illness representations. Adjustments to the Illness Perception Questionnaire-Revised are suggested to improve the evaluation of illness perception in terms of dispersion of scores, emotional impact, coping strategies and treatment, and social support, and ultimately to enhance interventions designed to promote treatment compliance. PMID:25626700

  11. A survey of quantum image representations

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Iliyasu, Abdullah M.; Venegas-Andraca, Salvador E.

    2016-01-01

    Quantum image processing (QIMP) is devoted to utilizing the quantum computing technologies to capture, manipulate, and recover quantum images in different formats and for different purposes. Logically, percolating this requires that representations to encode images based on the quantum mechanical composition of any potential quantum computing hardware be conjured. This paper gathers the current mainstream quantum image representations (QIRs) and discusses the advances made in the area. Some similarities, differences, and likely applications for some of the available QIRs are reviewed. We believe this compendium will provide the readership an overview of progress witnessed in the area of QIMP while also simulating further interest to pursue more advanced research in it.

  12. The Feynman-Schwinger representation in QCD

    SciTech Connect

    Yu. A. Simonov; J.A. Tjon

    2002-05-01

    The proper time path integral representation is derived explicitly for Green's functions in QCD. After an introductory analysis of perturbative properties, the total gluonic field is separated in a rigorous way into a nonperturbative background and valence gluon part. For nonperturbative contributions the background perturbation theory is used systematically, yielding two types of expansions,illustrated by direct physical applications. As an application, we discuss the collinear singularities in the Feynman-Schwinger representation formalism. Moreover, the generalization to nonzero temperature is made and expressions for partition functions in perturbation theory and nonperturbative background are explicitly written down.

  13. On Matrix Representations of Participation Constraints

    NASA Astrophysics Data System (ADS)

    Hartmann, Sven; Leck, Uwe; Link, Sebastian

    We discuss the existence of matrix representations for generalised and minimum participation constraints which are frequently used in database design and conceptual modelling. Matrix representations, also known as Armstrong relations, have been studied in literature e.g. for functional dependencies and play an important role in example-based design and for the implication problem of database constraints. The major tool to achieve the results in this paper is a theorem of Hajnal and Szemerédi on the occurrence of clique graphs in a given graph.

  14. Human spatial representation: insights from animals.

    PubMed

    Wang, Ranxiao; Spelke, Elizabeth

    2002-09-01

    HUMAN NAVIGATION IS SPECIAL: we use geographic maps to capture a world far beyond our unaided locomotion. In consequence, human navigation is widely thought to depend on internalized versions of these maps - enduring, geocentric 'cognitive maps' capturing diverse information about the environment. Contrary to this view, we argue that human navigation is best studied in relation to research on navigating animals as humble as ants. This research provides evidence that animals, including humans, navigate primarily by representations that are momentary rather than enduring, egocentric rather than geocentric, and limited in the environmental information that they capture. Uniquely human forms of navigation build on these representations. PMID:12200179

  15. Dispersion Representation of Deeply Virtual Compton Scattering

    NASA Astrophysics Data System (ADS)

    Pasquini, B.

    2015-09-01

    We discuss the dispersive representation of the D-term form factor for hard exclusive reactions, using unsubtracted t-channel dispersion relations. This representation provides a microscopical interpretation of the physical content of the D-term form factor in terms of t-channel exchanges with the appropriate quantum numbers. The contribution from two-pion intermediate states is explicitly evaluated, and the corresponding results for the D-term form factor as function of t as well as at t = 0 are discussed in comparison with available model predictions and phenomenological parametrizations.

  16. [The fragmentation of representational space in schizophrenia].

    PubMed

    Plagnol, A; Oïta, M; Montreuil, M; Granger, B; Lubart, T

    2003-01-01

    Existent neurocognitive models of schizophrenia converge towards a core of impairments involving working memory, context processing, action planning, controlled and intentional processing. However, the emergence of this core remains itself difficult to explain and more specific hypotheses do not explain the heterogeneity of schizophrenia. To overcome these limits, we propose a new paradigm based on representational theory from cognitive science. Some recent developments of this theory enable us to describe a subjective universe as a representational space which is displayed from memory. We outline a conceptual framework to construct such a representational space from analogical -representations that can be activated in working memory and are connected to a network of symbolic structures. These connections are notably made through an analytic process of the analogical fragments, which involves the attentional focus. This framework allows us to define rigorously some defense processes in response to traumatic tensions that are expressed on the representational space. The fragmentation of representational space is a consequence of a defensive denial based on an impairment of the analytic process. The fragmentation forms some parasitic areas in memory which are excluded from the main part of the representational space and disturb information processing. The key clinical concepts of paranoid syndromes can be defined in this conceptual framework: mental automatism, delusional intuition, acute destructuration, psychotic dissociation, and autistic withdrawal. We show that these syndromes imply each other, which in return increases the fragmentation of the representational space. Some new concepts emerge naturally in this framework, such as the concept of "suture" which is defined as a link between a parasitic area and the main representational space. Schizophrenia appears as a borderline case of fragmentation of the representational space. This conceptual framework is

  17. Building Hierarchical Representations for Oracle Character and Sketch Recognition.

    PubMed

    Jun Guo; Changhu Wang; Roman-Rangel, Edgar; Hongyang Chao; Yong Rui

    2016-01-01

    In this paper, we study oracle character recognition and general sketch recognition. First, a data set of oracle characters, which are the oldest hieroglyphs in China yet remain a part of modern Chinese characters, is collected for analysis. Second, typical visual representations in shape- and sketch-related works are evaluated. We analyze the problems suffered when addressing these representations and determine several representation design criteria. Based on the analysis, we propose a novel hierarchical representation that combines a Gabor-related low-level representation and a sparse-encoder-related mid-level representation. Extensive experiments show the effectiveness of the proposed representation in both oracle character recognition and general sketch recognition. The proposed representation is also complementary to convolutional neural network (CNN)-based models. We introduce a solution to combine the proposed representation with CNN-based models, and achieve better performances over both approaches. This solution has beaten humans at recognizing general sketches. PMID:26571529

  18. Elemental Representations of Stimuli in Associative Learning

    ERIC Educational Resources Information Center

    Harris, Justin A.

    2006-01-01

    This article reviews evidence and theories concerning the nature of stimulus representations in Pavlovian conditioning. It focuses on the elemental approach developed in stimulus sampling theory (R. C. Atkinson & W. K. Estes, 1963; R. R. Bush & F. Mosteller, 1951b) and extended by I. P. L. McLaren and N. J. Mackintosh (2000, 2002) and contrasts…

  19. 8 CFR 1003.16 - Representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... choice in accordance with 8 CFR part 1292, at no expense to the government. ... Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation....

  20. 8 CFR 1003.16 - Representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... choice in accordance with 8 CFR part 1292, at no expense to the government. ... Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation....

  1. 8 CFR 1003.16 - Representation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... choice in accordance with 8 CFR part 1292, at no expense to the government. ... Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation....

  2. 8 CFR 1003.16 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... choice in accordance with 8 CFR part 1292, at no expense to the government. ... Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation....

  3. 8 CFR 1003.16 - Representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... choice in accordance with 8 CFR part 1292, at no expense to the government. ... Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation....

  4. Representation of magnetic fields in space

    NASA Technical Reports Server (NTRS)

    Stern, D. P.

    1975-01-01

    Several methods by which a magnetic field in space can be represented are reviewed with particular attention to problems of the observed geomagnetic field. Time dependence is assumed to be negligible, and five main classes of representation are described by vector potential, scalar potential, orthogonal vectors, Euler potentials, and expanded magnetic field.

  5. Effects of Spatial Cueing on Representational Momentum

    ERIC Educational Resources Information Center

    Hubbard, Timothy L.; Kumar, Anuradha Mohan; Carp, Charlotte L.

    2009-01-01

    Effects of a spatial cue on representational momentum were examined. If a cue was present during or after target motion and indicated the location at which the target would vanish or had vanished, forward displacement of that target decreased. The decrease in forward displacement was larger when cues were present after target motion than when cues…

  6. The Impact of Immigration on Congressional Representation.

    ERIC Educational Resources Information Center

    Bouvier, Leon

    Explanation of shifts in U.S. Congressional representation among states have often overlooked the effects of international migration on the size and distribution of the U.S. population. Seventy percent of recent U.S. immigrants have settled in California, New York, Texas, Florida, New Jersey, and Illinois. Estimates of the distribution of…

  7. Graphical Representations of Electronic Search Patterns.

    ERIC Educational Resources Information Center

    Lin, Xia; And Others

    1991-01-01

    Discussion of search behavior in electronic environments focuses on the development of GRIP (Graphic Representor of Interaction Patterns), a graphing tool based on HyperCard that produces graphic representations of search patterns. Search state spaces are explained, and forms of data available from electronic searches are described. (34…

  8. Diagrammatic Representation and Event Memory in Preschoolers

    ERIC Educational Resources Information Center

    Lambert, E. Beverley

    2007-01-01

    This study investigated the use of diagrammatic representation as an aid for recalling a past event for 30 4-5-year-olds in their preschool year prior to commencing primary school. The children were randomly placed into one of two groups: "talkers" (verbal memory) or "drawers" (diagrammatic memory). They were interviewed individually, both one day…

  9. Retrieving Enduring Spatial Representations after Disorientation

    ERIC Educational Resources Information Center

    Li, Xiaoou; Mou, Weimin; McNamara, Timothy P.

    2012-01-01

    Four experiments tested whether there are enduring spatial representations of objects' locations in memory. Previous studies have shown that under certain conditions the internal consistency of pointing to objects using memory is disrupted by disorientation. This disorientation effect has been attributed to an absence of or to imprecise enduring…

  10. 77 FR 25547 - Representation-Case Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... unchanged. The final rule, published December 22, 2011, at 76 FR 80138, will be effective on April 30, 2012... FR 80138, stated that any dissenting or concurring statements would be published separately in the... dissenting statements regarding the Board's final rule concerning representation- case procedures, 76...

  11. Electromagnetic Concepts in Mathematical Representation of Physics.

    ERIC Educational Resources Information Center

    Albe, Virginie; Venturini, Patrice; Lascours, Jean

    2001-01-01

    Addresses the use of mathematics when studying the physics of electromagnetism. Focuses on common electromagnetic concepts and their associated mathematical representation and arithmetical tools. Concludes that most students do not understand the significant aspects of physical situations and have difficulty using relationships and models specific…

  12. Mind games: the mental representation of conflict.

    PubMed

    Halevy, Nir; Chou, Eileen Y; Murnighan, J Keith

    2012-01-01

    Perception and misperception play a pivotal role in conflict and negotiation. We introduce a framework that explains how people think about their outcome interdependence in conflict and negotiation and how their views shape their behavior. Seven studies show that people's mental representations of conflict are predictably constrained to a small set of possibilities with important behavioral and social consequences. Studies 1 and 2 found that, when prompted to represent a conflict in matrix form, more than 70% of the people created 1 of 4 archetypal mixed-motive games (out of 576 possibilities): Maximizing Difference, Assurance, Chicken, and Prisoner's Dilemma. Study 3 demonstrated that these mental representations relate in predictable ways to negotiators' fixed-pie perceptions. Studies 4-6 showed that these mental representations shape individuals' behavior and interactions with others, including cooperation, perspective taking, and use of deception in negotiation, and through them, conflict's outcomes. Study 7 found that the games that people think they are playing influence how their counterparts see them, as well as their counterparts' negotiation expectations. Overall, the findings document noteworthy regularities in people's mental representations of outcome interdependence in conflict and illustrate that 4 archetypal games can encapsulate fundamental psychological processes that emerge repeatedly in conflict and negotiation. PMID:21910551

  13. Domain Knowledge Representation for Instructional Analysis.

    ERIC Educational Resources Information Center

    Jones, Mark K.; And Others

    1990-01-01

    Presents a knowledge representation model that was designed for instructional decision making. Topics discussed include classification models for instructional design; artificial intelligence; semantic networks; natural language; and data models, including network and hierarchical models. An example is given of knowledge analysis for a secondary…

  14. Nuclear dynamics in the Wigner representation

    SciTech Connect

    Bonasera, A.; Kondratyev, V.N.; Smerzi, A.; Remler, E.A. Dipartimento di Fisica dell' Universita di Catania, 57, Corso Italia, 95129 Catania Institute for Nuclear Research, 47, Pr. Nauki, Kiev, 252 028 Department of Physics, The College of William Mary, Williamsburg, Virginia 23185 )

    1993-07-26

    The quantum equation of motion of the density operator in the Wigner representation is solved using a stochastic approach. Nuclear ground states and an asymmetric nucleus-nucleus collision below the Coulomb barrier are studied. Quantum effects are shown to cause significant differences in comparison to results obtained from the classical Vlasov equation.

  15. A Mathematical Representation of the Genetic Code

    NASA Astrophysics Data System (ADS)

    Hill, Vanessa J.; Rowlands, Peter

    Algebraic and geometric representations of the genetic code are used to show their functions in coding for amino acids. The algebra is a 64-part vector quaternion combination, and the geometry is based on the structure of the regular icosidodecahedron. An almost perfect pattern suggests that this is a biologically significant way of representing the genetic code.

  16. 15 CFR 90.18 - Representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Representation. 90.18 Section 90.18 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE PROCEDURE FOR CHALLENGING CERTAIN POPULATION AND INCOME ESTIMATES §...

  17. 15 CFR 90.18 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Representation. 90.18 Section 90.18 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE PROCEDURE FOR CHALLENGING CERTAIN POPULATION AND INCOME ESTIMATES §...

  18. 15 CFR 90.18 - Representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Representation. 90.18 Section 90.18 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE PROCEDURE FOR CHALLENGING CERTAIN POPULATION AND INCOME ESTIMATES §...

  19. 15 CFR 90.18 - Representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Representation. 90.18 Section 90.18 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE PROCEDURE FOR CHALLENGING CERTAIN POPULATION AND INCOME ESTIMATES §...

  20. Phonological Representations and Early Literacy in Chinese

    ERIC Educational Resources Information Center

    Kidd, Joanna C.; Shum, Kathy Kar-Man; Ho, Connie Suk-Han; Au, Terry Kit-fong

    2015-01-01

    Phonological processing skills predict early reading development, but what underlies developing phonological processing skills? Phonological representations of 140 native Cantonese-speaking Chinese children (age 4-10) were assessed with speech gating, mispronunciation detection, and nonword repetition tasks; their nonverbal IQ, reading, and…

  1. 15 CFR 785.5 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Representation. 785.5 Section 785.5 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE ADDITIONAL PROTOCOL REGULATIONS ENFORCEMENT §...

  2. Asymmetric Translation between Multiple Representations in Chemistry

    ERIC Educational Resources Information Center

    Lin, Yulan I.; Son, Ji Y.; Rudd, James A., II

    2016-01-01

    Experts are more proficient in manipulating and translating between multiple representations (MRs) of a given concept than novices. Studies have shown that instruction using MR can increase student understanding of MR, and one model for MR instruction in chemistry is the chemistry triplet proposed by Johnstone. Concreteness fading theory suggests…

  3. 15 CFR 280.205 - Representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Representation. 280.205 Section 280.205 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS...

  4. 15 CFR 280.205 - Representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Representation. 280.205 Section 280.205 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS...

  5. 15 CFR 280.205 - Representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Representation. 280.205 Section 280.205 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS...

  6. 15 CFR 280.205 - Representation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Representation. 280.205 Section 280.205 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS...

  7. 15 CFR 280.205 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Representation. 280.205 Section 280.205 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS...

  8. Schoolchildren's Social Representations on Bullying Causes

    ERIC Educational Resources Information Center

    Thornberg, Robert

    2010-01-01

    The aim of the present study is to investigate schoolchildren's social representations on the causes of bullying. Individual qualitative interviews were conducted with 56 schoolchildren recruited from five elementary schools in Sweden. Mixed methods (grounded theory as well as descriptive statistic methods) were used to analyze data. According to…

  9. 7 CFR 917.15 - Representation area.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Representation area. 917.15 Section 917.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN...

  10. Cultural Representations of Minorities in Hungarian Textbooks

    ERIC Educational Resources Information Center

    Weninger, Csilla; Williams, J. Patrick

    2005-01-01

    This article reports research analyzing cultural representations of minorities in Hungarian elementary school textbooks currently used throughout the country. A convenient sample representing more than 75% of first and fourth grade reading books was collected from three academic and public libraries in Hungary. Using content analysis techniques,…

  11. Processing of Color Words Activates Color Representations

    ERIC Educational Resources Information Center

    Richter, Tobias; Zwaan, Rolf A.

    2009-01-01

    Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

  12. Attachment Representation of Institutionalized Children in Japan

    ERIC Educational Resources Information Center

    Katsurada, Emiko

    2007-01-01

    This exploratory study represents one of the first attachment investigations of Japanese children who have been institutionalized. Mental representation of attachment was assessed using George and Solomon's (1990, 1996, 2000) Attachment Doll Play Classification System of the Bretherton et al. (1990) doll play story stems. Participants were 32…

  13. 10 CFR 72.206 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Representation. 72.206 Section 72.206 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C WASTE Provision of...

  14. Maximum likelihood representation of MIPAS profiles

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.; Glatthor, N.; Plieninger, J.

    2015-03-01

    In order to avoid problems connected with the content of a priori information in volume mixing ratio vertical profiles measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a user-friendly representation of the data has been developed which will be made available in addition to the regular data product. In this representation, the data will be provided on a fixed pressure grid coarse enough to allow a virtually unconstrained retrieval. As to avoid data interpolation, the grid is chosen to be a subset of the pressure grids used by the Chemistry Climate Model Initiative and the Data Initiative within the Stratosphere-troposphere Processes And their Role in Climate (SPARC) project as well as the Intergovernmental Panel of Climate Change climatologies and model calculations. For representation, the profiles have been transformed to boxcar base functions, which means that volume mixing ratios are constant within a layer. This representation is thought to be more adequate for comparison with model data. While this method is applicable also to vertical profiles of other species, the method is discussed using ozone as an example.

  15. Maximum likelihood representation of MIPAS profiles

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.; Glatthor, N.; Plieninger, J.

    2015-07-01

    In order to avoid problems connected with the content of a priori information in volume mixing ratio vertical profiles measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a user-friendly representation of the data has been developed which will be made available in addition to the regular data product. In this representation, the data will be provided on a fixed pressure grid coarse enough to allow a virtually unconstrained retrieval. To avoid data interpolation, the grid is chosen to be a subset of the pressure grids used by the Chemistry-Climate Model Initiative and the Data Initiative within the Stratosphere-troposphere Processes And their Role in Climate (SPARC) project as well as the Intergovernmental Panel of Climate Change climatologies and model calculations. For representation, the profiles have been transformed to boxcar base functions, which means that volume mixing ratios are constant within a layer. This representation is thought to be more adequate for comparison with model data. While this method is applicable also to vertical profiles of other species, the method is discussed using ozone as an example.

  16. 7 CFR 981.31 - Membership representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board... who market their almonds through cooperative handlers; and (2) Those growers who market their...

  17. 7 CFR 981.31 - Membership representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board... who market their almonds through cooperative handlers; and (2) Those growers who market their...

  18. 7 CFR 981.31 - Membership representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board... who market their almonds through cooperative handlers; and (2) Those growers who market their...

  19. 7 CFR 981.31 - Membership representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board... who market their almonds through cooperative handlers; and (2) Those growers who market their...

  20. 7 CFR 981.31 - Membership representation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board... who market their almonds through cooperative handlers; and (2) Those growers who market their...

  1. 75 FR 26062 - Representation Election Procedure

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ... representative. 74 FR 56,750. In its NPRM, the Board stated its belief, based on the language of the RLA... rule changes regarding representation election procedures. Meeting Notice, 74 FR 57,427 (Nov. 6, 2009... a comment period of not less than 60 days.'' Exec. Order No. 12,866, 58 FR 51,735 (1993). ATA...

  2. Process and representation in graphical displays

    NASA Technical Reports Server (NTRS)

    Gillan, Douglas J.; Lewis, Robert; Rudisill, Marianne

    1990-01-01

    How people comprehend graphics is examined. Graphical comprehension involves the cognitive representation of information from a graphic display and the processing strategies that people apply to answer questions about graphics. Research on representation has examined both the features present in a graphic display and the cognitive representation of the graphic. The key features include the physical components of a graph, the relation between the figure and its axes, and the information in the graph. Tests of people's memory for graphs indicate that both the physical and informational aspect of a graph are important in the cognitive representation of a graph. However, the physical (or perceptual) features overshadow the information to a large degree. Processing strategies also involve a perception-information distinction. In order to answer simple questions (e.g., determining the value of a variable, comparing several variables, and determining the mean of a set of variables), people switch between two information processing strategies: (1) an arithmetic, look-up strategy in which they use a graph much like a table, looking up values and performing arithmetic calculations; and (2) a perceptual strategy in which they use the spatial characteristics of the graph to make comparisons and estimations. The user's choice of strategies depends on the task and the characteristics of the graph. A theory of graphic comprehension is presented.

  3. Twentieth-Century Art: Issues of Representation.

    ERIC Educational Resources Information Center

    Springer, Julie

    1990-01-01

    Presents lesson plans designed for secondary students that assess the role of naturalistic representation in twentieth-century art by examining the artwork of four artists: Pablo Picasso, Rene Magritte, David Smith, and Jackson Pollock. Provides background information on each illustration, and outlines discussion and art production activities for…

  4. A Hybrid Constraint Representation and Reasoning Framework

    NASA Technical Reports Server (NTRS)

    Golden, Keith; Pang, Wan-Lin

    2003-01-01

    This paper introduces JNET, a novel constraint representation and reasoning framework that supports procedural constraints and constraint attachments, providing a flexible way of integrating the constraint reasoner with a run- time software environment. Attachments in JNET are constraints over arbitrary Java objects, which are defined using Java code, at runtime, with no changes to the JNET source code.

  5. Uncertainty Representation in Stochastic Reservoir Optimization

    NASA Astrophysics Data System (ADS)

    Lamontagne, J. R.; Stedinger, J. R.; Shoemaker, C. A.; Tan, S. N.

    2014-12-01

    Water resources managers attempt to operate reservoir and hydropower systems to maximize system objectives, subject to a host of physical and policy constraints, and in light of uncertainty about future conditions. Optimization models are widely used to advise the decision making process. An important aspect of such models is how uncertainties related to future hydrologic and economic conditions are represented, and the extent to which different uncertainty representations affect the quality of recommended decisions. This study explores the consequences of different uncertainty representations in stochastic optimization models of hydropower systems by comparing simulated system performance using different stochastic optimization models. An important question is whether the added computational burden from greater uncertainty resolution (which can be prohibitive for operational models in many cases) actually improves model recommendations. This is particularly relevant as more complex, ensemble forecasts are incorporated into short- and mid-term planning models. Another important consideration is how watershed hydrology (both seasonal and episodic characteristics), system size, economic context, and the temporal resolution of the model influence how uncertainty should be represented. These topics are explored through several US examples including a sampling stochastic dynamic programming (SSDP) model of a small single-reservoir system on the Kennebec River in Maine, and a stochastic programming model of the large multi-reservoir Federal Columbia River system in the Pacific Northwest. These studies highlight the importance of flexible model frameworks which allow exploration of different representations of a system and of uncertainties before locking operational decision support system development into a specific representation.

  6. Knowledge representation issues for explaining plans

    NASA Technical Reports Server (NTRS)

    Prince, Mary Ellen; Johannes, James D.

    1988-01-01

    Explanations are recognized as an important facet of intelligent behavior. Unfortunately, expert systems are currently limited in their ability to provide useful, intelligent justifications of their results. We are currently investigating the issues involved in providing explanation facilities for expert planning systems. This investigation addresses three issues: knowledge content, knowledge representation, and explanation structure.

  7. Genetics Reasoning with Multiple External Representations.

    ERIC Educational Resources Information Center

    Tsui, Chi-Yan; Treagust, David F.

    2003-01-01

    Explores a case study of a class of 10th grade students whose learning of genetics involved activities using BioLogica, a computer program that features multiple external representations (MERs). Findings indicate that the MERs in BioLogica contributed to students' development of genetics reasoning by engendering their motivation and interest but…

  8. Identification and Representation of Leadership Problems.

    ERIC Educational Resources Information Center

    Forsythe, George B.; And Others

    The first step in a long-term research effort to investigate the relationship between knowledge and its use in the practice of leadership is described in this paper. Detailed interviews with a random sample of 37 senior West Point cadets to were conducted investigate the identification and causal representation of human performance problem…

  9. Representation of Legal Knowledge for Conceptual Retrieval.

    ERIC Educational Resources Information Center

    Cross, George R.; deBessonet, Cary G.

    1985-01-01

    Describes traditional legal information retrieval systems--Juris, Lexis, Westlaw--and several new rule-based, knowledge-based, legal knowledge reasoning, and analytical legal information systems--Waterman and Peterson's Legal Decisionmaking System, Hafner's Legal Information Retrieval System, McCarty's TAXMAN, and the deBessonet representation of…

  10. Children's Understanding of Pictorial and Mental Representations.

    ERIC Educational Resources Information Center

    Slaughter, Virginia

    1998-01-01

    Two studies demonstrated dissociation between preschoolers' understanding of pictorial and mental representations. Results showed that false picture tasks were significantly easier than false belief tasks. There was no correlation between performance on the two. Children were trained on false belief, false picture, or number conservation tasks;…

  11. Female Representation by Type of Class

    ERIC Educational Resources Information Center

    Physics Teacher, 2012

    2012-01-01

    Last month we saw that females make up about 47% of all high school physics students in the United States. This number has changed little since 1997. This month, we take a closer look at female representation by type of class. We last collected class-specific data in 1993; that year, 43% of all high school physics students were female. However,…

  12. Media and the Representation of Others

    ERIC Educational Resources Information Center

    Fursich, Elfriede

    2010-01-01

    This article criticises the role the mass media has played in constructing an idea of the Other, that is, people outside the national mainstream or other nationalities. It explains how the media promote or hinder a positive outlook on cultural diversity. Based on a review of the scholarly debate on media representations of Others, it identifies…

  13. 76 FR 37291 - Representation Case Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-27

    ...., Washington, DC 20570. During the public meeting, interested persons may share their views on the proposed amendments to the Board's rules governing representation case procedures, published at 76 FR 15307 (June 22... Rulemaking (NPRM) (76 FR 15307), proposing to amend its rules and regulations governing the filing...

  14. Multisensory body representation in autoimmune diseases.

    PubMed

    Finotti, Gianluca; Costantini, Marcello

    2016-01-01

    Body representation has been linked to the processing and integration of multisensory signals. An outstanding example of the pivotal role played by multisensory mechanisms in body representation is the Rubber Hand Illusion (RHI). In this paradigm, multisensory stimulation induces a sense of ownership over a fake limb. Previous work has shown high interindividual differences in the susceptibility to the RHI. The origin of this variability remains largely unknown. Given the tight and bidirectional communication between the brain and the immune system, we predicted that the origin of this variability could be traced, in part, to the immune system's functioning, which is altered by several clinical conditions, including Coeliac Disease (CD). Consistent with this prediction, we found that the Rubber Hand Illusion is stronger in CD patients as compared to healthy controls. We propose a biochemical mechanism accounting for the dependency of multisensory body representation upon the Immune system. Our finding has direct implications for a range of neurological, psychiatric and immunological conditions where alterations of multisensory integration, body representation and dysfunction of the immune system co-exist. PMID:26867786

  15. Language Influence on Children's Cognitive Number Representation

    ERIC Educational Resources Information Center

    Alsawaie, Othman N.

    2004-01-01

    This study examined the effect of language on children's cognitive representation of number. The sample for the study consisted of 90 Arabic speaking children with a mean age of 80 months. Children were interviewed individually and asked to represent written two-digit numbers using base-10 blocks. A new approach for testing the linguistic…

  16. Understanding Linear Functions and Their Representations

    ERIC Educational Resources Information Center

    Wells, Pamela J.

    2015-01-01

    Linear functions are an important part of the middle school mathematics curriculum. Students in the middle grades gain fluency by working with linear functions in a variety of representations (NCTM 2001). Presented in this article is an activity that was used with five eighth-grade classes at three different schools. The activity contains 15 cards…

  17. Digital Art Making as a Representational Process

    ERIC Educational Resources Information Center

    Halverson, Erica Rosenfeld

    2013-01-01

    In this article I bring artistic production into the learning sciences conversation by using the production of representations as a bridging concept between art making and the new literacies. Through case studies with 4 youth media arts organizations across the United States I ask how organizations structure the process of producing…

  18. Information Graphic Classification, Decomposition and Alternative Representation

    ERIC Educational Resources Information Center

    Gao, Jinglun

    2012-01-01

    This thesis work is mainly focused on two problems related to improving accessibility of information graphics for visually impaired users. The first problem is automated analysis of information graphics for information extraction and the second problem is multi-modal representations for accessibility. Information graphics are graphical…

  19. 7 CFR 917.15 - Representation area.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Representation area. 917.15 Section 917.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN...

  20. Conceptual size representation in ventral visual cortex.

    PubMed

    Gabay, Shai; Kalanthroff, Eyal; Henik, Avishai; Gronau, Nurit

    2016-01-29

    Recent findings suggest that visual objects may be mapped along the ventral occipitotemporal cortex according to their real-world size (Konkle and Oliva, 2012). It has been argued that such mapping does not reflect an abstract, conceptual size representation, but rather the visual or functional properties associated with small versus big real-world objects. To determine whether a more abstract conceptual size representation may affect visual cortical activation we used meaningless geometrical shapes, devoid of semantic or functional associations, which were associated with specific size representations by virtue of extensive training. Following training, participants underwent functional magnetic resonance imaging (fMRI) scanning while performing a conceptual size comparison task on the geometrical shapes. In addition, a size comparison task was conducted for numeral digits denoting small and big numbers. A region-of-interest analysis revealed larger blood oxygenation level dependent (BOLD) responses for conceptually 'big' than for conceptually 'small' shapes, as well as for big versus small numbers, within medial (parahippocampal place area, PPA) and lateral (occipital place area, OPA) place-selective regions. Processing of the 'big' visual shapes further elicited enhanced activation in early visual cortex, possibly reflecting top-down projections from PPA. By using arbitrary shapes and numbers we minimized visual, categorical, or functional influences on fMRI measurement, providing evidence for a possible neural mechanism underlying the representation of abstract conceptual size within the ventral visual stream. PMID:26731198

  1. Employing Multiple Representations for Chinese Information Retrieval.

    ERIC Educational Resources Information Center

    Kwok, K. L.

    1999-01-01

    Discusses information retrieval in the Chinese language and describes three representation methods for texts: 1-gram or character, bigram, and short-word. Describes a study that investigated using more than one method simultaneously to improve retrieval effectiveness and considers word segmentation and costs. (Author/LRW)

  2. Designing and Evaluating Representations to Model Pedagogy

    ERIC Educational Resources Information Center

    Masterman, Elizabeth; Craft, Brock

    2013-01-01

    This article presents the case for a theory-informed approach to designing and evaluating representations for implementation in digital tools to support Learning Design, using the framework of epistemic efficacy as an example. This framework, which is rooted in the literature of cognitive psychology, is operationalised through dimensions of fit…

  3. Atypical Neural Self-Representation in Autism

    ERIC Educational Resources Information Center

    Lombardo, Michael V.; Chakrabarti, Bhismadev; Bullmore, Edward T.; Sadek, Susan A.; Pasco, Greg; Wheelwright, Sally J.; Suckling, John; Baron-Cohen, Simon

    2010-01-01

    The "self" is a complex multidimensional construct deeply embedded and in many ways defined by our relations with the social world. Individuals with autism are impaired in both self-referential and other-referential social cognitive processing. Atypical neural representation of the self may be a key to understanding the nature of such impairments.…

  4. Multisensory body representation in autoimmune diseases

    PubMed Central

    Finotti, Gianluca; Costantini, Marcello

    2016-01-01

    Body representation has been linked to the processing and integration of multisensory signals. An outstanding example of the pivotal role played by multisensory mechanisms in body representation is the Rubber Hand Illusion (RHI). In this paradigm, multisensory stimulation induces a sense of ownership over a fake limb. Previous work has shown high interindividual differences in the susceptibility to the RHI. The origin of this variability remains largely unknown. Given the tight and bidirectional communication between the brain and the immune system, we predicted that the origin of this variability could be traced, in part, to the immune system’s functioning, which is altered by several clinical conditions, including Coeliac Disease (CD). Consistent with this prediction, we found that the Rubber Hand Illusion is stronger in CD patients as compared to healthy controls. We propose a biochemical mechanism accounting for the dependency of multisensory body representation upon the Immune system. Our finding has direct implications for a range of neurological, psychiatric and immunological conditions where alterations of multisensory integration, body representation and dysfunction of the immune system co-exist. PMID:26867786

  5. Social Representations as Dynamic Social Impact.

    ERIC Educational Resources Information Center

    Huguet, Pascal; Latane, Bibb

    1996-01-01

    Describes Social Representation Theory (SRT), an important and controversial development in European social constructivism. Argues that, although SRT and Dynamic Social Impact Theory (DSIT) come from different research traditions, they are complementary. Maintains that DSIT goes further in providing a clear mechanism for how dialog creates…

  6. Social representations and normative beliefs of aging.

    PubMed

    Torres, Tatiana de Lucena; Camargo, Brigido Vizeu; Boulsfield, Andréa Barbará; Silva, Antônia Oliveira

    2015-12-01

    This study adopted the theory of social representations as a theoretical framework in order to characterize similarities and differences in social representations and normative beliefs of aging for different age groups. The 638 participants responded to self-administered questionnaire and were equally distributed by sex and age. The results show that aging is characterized by positive stereotypes (knowledge and experience); however, retirement is linked to aging, but in a negative way, particularly for men, involving illness, loneliness and disability. When age was considered, it was verified that the connections with the representational elements became more complex for older groups, showing social representation functionality, largely for the elderly. Adulthood seems to be preferred and old age is disliked. There were divergences related to the perception of the beginning of life phases, especially that of old age. Work was characterized as the opposite of aging, and it revealed the need for actions intended for the elderly and retired workers, with post-retirement projects. In addition, it suggests investment in public policies that encourage intergenerational contact, with efforts to reduce intolerance and discrimination based on age of people. PMID:26691788

  7. Rethinking the Representation Problem in Curriculum Inquiry

    ERIC Educational Resources Information Center

    Green, Bill

    2010-01-01

    The consolidation of reconceptualism as a distinctive tradition in curriculum inquiry is commonly understood to go hand-in-hand with the decline and even eclipse of an explicit political orientation in such work. This paper offers an alternative argument, focusing on a re-assessment of what has been called the representation problem, and exploring…

  8. Understanding Primes: The Role of Representation

    ERIC Educational Resources Information Center

    Zazkis, Rina; Liljedahl, Peter

    2004-01-01

    In this article we investigate how preservice elementary school (K-7) teachers understand the concept of prime numbers. We describe participants' understanding of primes and attempt to detect factors that influence their understanding. Representation of number properties serves as a lens for the analysis of participants' responses. We suggest that…

  9. 29 CFR 18.34 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ADMINISTRATIVE LAW JUDGES General § 18.34 Representation. (a) Appearances. Any party shall have the right to... appearance is made. (c) Rights of parties. Every party shall have the right of timely notice and all other... the right to make a written or oral statement of position. At the discretion of the administrative...

  10. 24 CFR 180.305 - Representation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Representation. 180.305 Section 180... BUSINESS OPPORTUNITY CONSOLIDATED HUD HEARING PROCEDURES FOR CIVIL RIGHTS MATTERS Parties § 180.305... appearance. (c) An attorney must be admitted to practice before a Federal Court or the highest court in...

  11. 24 CFR 180.305 - Representation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Representation. 180.305 Section 180... BUSINESS OPPORTUNITY CONSOLIDATED HUD HEARING PROCEDURES FOR CIVIL RIGHTS MATTERS Parties § 180.305... appearance. (c) An attorney must be admitted to practice before a Federal Court or the highest court in...

  12. 7 CFR 917.15 - Representation area.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Representation area. 917.15 Section 917.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN...

  13. 7 CFR 917.15 - Representation area.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Representation area. 917.15 Section 917.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN...

  14. 7 CFR 917.15 - Representation area.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Representation area. 917.15 Section 917.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN...

  15. Representations of stem cell clinics on Twitter.

    PubMed

    Kamenova, Kalina; Reshef, Amir; Caulfield, Timothy

    2014-12-01

    The practice of travelling abroad to receive unproven and unregulated stem cell treatments has become an increasingly problematic global phenomenon known as 'stem cell tourism'. In this paper, we examine representations of nine major clinics and providers of such treatments on the microblogging network Twitter. We collected and conducted a content analysis of Twitter posts (n = 363) by these establishments and by other users mentioning them, focusing specifically on marketing claims about treatment procedures and outcomes, discussions of safety and efficacy of stem cell transplants, and specific representations of patients' experiences. Our analysis has shown that there were explicit claims or suggestions of benefits associated with unproven stem cell treatments in approximately one third of the tweets and that patients' experiences, whenever referenced, were presented as invariably positive and as testimonials about the efficacy of stem cell transplants. Furthermore, the results indicated that the tone of most tweets (60.2 %) was overwhelmingly positive and there were rarely critical discussions about significant health risks associated with unproven stem cell therapies. When placed in the context of past research on the problems associated with the marketing of unproven stem cell therapies, this analysis of representations on Twitter suggests that discussions in social media have also remained largely uncritical of the stem cell tourism phenomenon, with inaccurate representations of risks and benefits for patients. PMID:24970380

  16. Software GOLUCA: Knowledge Representation in Mental Calculation

    ERIC Educational Resources Information Center

    Casas-Garcia, Luis M.; Luengo-Gonzalez, Ricardo; Godinho-Lopes, Vitor

    2011-01-01

    We present a new software, called Goluca (Godinho, Luengo, and Casas, 2007), based on the technique of Pathfinder Associative Networks (Schvaneveldt, 1989), which produces graphical representations of the cognitive structure of individuals in a given field knowledge. In this case, we studied the strategies used by teachers and its relationship…

  17. Internal representation of two-dimensional shape.

    PubMed

    Makioka, S; Inui, T; Yamashita, H

    1996-01-01

    The psychological space of shapes has been studied in many experiments. However, how shapes are represented in the brain has not been a major issue in psychological literature. Here, the characteristics of internal representation and how it was formed have been considered and an attempt has been made to explain the results of experiments in a unified manner. First, the data of similarity of alphabetic characters and random-dot patterns were reexamined. Multivariate analysis suggested that those patterns were represented by the combination of global features. Second, three-layer neural networks were trained to perform categorization or identity transformation of the same sets of patterns as used in psychological experiments, and activation patterns of the hidden units were analyzed. When the network learned categorization of the patterns, its internal representation was not similar to the representation suggested by psychological experiments. But a network which learned identity transformation of the patterns could acquire such an internal representation. The transformation performed by this kind of network is similar to principal-component analysis in that it projects the input image onto a lower-dimensional space. From these results it is proposed that two-dimensional shapes are represented in human brain by a process like principal-component analysis. This idea is compatible with the findings in neurophysiological studies about higher visual areas. PMID:8938008

  18. Tilt representation beyond the retinotopic level.

    PubMed

    Parwaga, Sandeep; Buckley, David; Duke, Philip A

    2016-01-01

    We perceive a stable visual world, which enables successful interaction with our environment, despite movements of the eyes, head, and body. How are such perceptions formed? One possibility is that retino-centric visual input is transformed into representations at higher levels, such as head-, body-, or world-centered representations. We investigated this hypothesis using the tilt aftereffect in a balanced adaptation paradigm designed to isolate head-, body-, and world-centered aftereffects. Observers adapted to two oppositely tilted stimuli, each contingent on one of two different gaze, head, or body directions. We found aftereffects contingent on gaze direction, but not head or body direction. This demonstrates that adaptable tilt representations exist in a head-centric frame but not in higher reference frames. These aftereffects may be attributed to adaptation of retinotopic tilt-sensitive neurons whose responses are modulated by gaze direction (gain fields). Such neurons could support functionally head-centric tilt representations and are found as early as V1. On the basis of our results we would not expect activity in tilt-sensitive neurons to be modulated by head or body direction. The balanced adaptation paradigm is a useful tool for examining properties of the process responsible for gaze modulation of activity in visual neurons. PMID:26868889

  19. Action co-representation and social exclusion.

    PubMed

    Costantini, Marcello; Ferri, Francesca

    2013-05-01

    Humans are thought to be able to form shared representations, considered a keystone of social cognition. However, whether and to what extent such representations are social in nature is still open for debate. In the present study, we address the question of whether action co-representation can be modulated by social attitudes, such as judgments about one's own social status. Two groups of participants performed an Interactive Simon task after the experimental induction of a feeling of social inclusion or exclusion (ostracism) by means of a virtual ball tossing game. Results showed a compatibility effect in included, but not in excluded participants. This indicates that judgments about one's own social status modulate action co-representation. We suggest that this modulation may occur by way of a redirection of one's attentional focus away from others when one experiences social exclusion. This is a far-reaching issue given the increasing need for integration in modern society. Indeed, if integration fails, modern society fails also. PMID:23543105

  20. Unilateral Vestibular Loss Impairs External Space Representation

    PubMed Central

    Borel, Liliane; Redon-Zouiteni, Christine; Cauvin, Pierre; Dumitrescu, Michel; Devèze, Arnaud; Magnan, Jacques; Péruch, Patrick

    2014-01-01

    The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss. PMID:24523916

  1. 12 CFR 349.11 - Unlawful representations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... forex account, for or on behalf of any person: (1) Guarantee such person or account against loss; (2... established for retail forex customers. (b) No implication of representation of engaging in prohibited acts... represent or imply in any manner whatsoever that any retail forex transaction or retail forex product...

  2. 12 CFR 349.11 - Unlawful representations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... forex account, for or on behalf of any person: (1) Guarantee such person or account against loss; (2... established for retail forex customers. (b) No implication of representation of engaging in prohibited acts... represent or imply in any manner whatsoever that any retail forex transaction or retail forex product...

  3. 12 CFR 240.11 - Unlawful representations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... forex account, for or on behalf of any person: (1) Guarantee such person or account against loss; (2... established for retail forex customers. (b) No implication of representation of engaging in prohibited acts... that any retail forex transaction or retail forex product has been sponsored, recommended, or...

  4. 12 CFR 349.11 - Unlawful representations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... forex account, for or on behalf of any person: (1) Guarantee such person or account against loss; (2... established for retail forex customers. (b) No implication of representation of engaging in prohibited acts... represent or imply in any manner whatsoever that any retail forex transaction or retail forex product...

  5. Representations of the Human Circulatory System

    ERIC Educational Resources Information Center

    Lopez-Manjon, Asuncion; Angon, Yolanda Postigo

    2009-01-01

    There is no agreement about the robustness of intuitive representations of the circulatory system and their susceptibility to change by instruction. In this paper, we analyse to what extent students with varying degrees of biology instruction and different ages (High School Health Science and Social Science students and first and final year…

  6. Probabilistic graphical model representation in phylogenetics.

    PubMed

    Höhna, Sebastian; Heath, Tracy A; Boussau, Bastien; Landis, Michael J; Ronquist, Fredrik; Huelsenbeck, John P

    2014-09-01

    Recent years have seen a rapid expansion of the model space explored in statistical phylogenetics, emphasizing the need for new approaches to statistical model representation and software development. Clear communication and representation of the chosen model is crucial for: (i) reproducibility of an analysis, (ii) model development, and (iii) software design. Moreover, a unified, clear and understandable framework for model representation lowers the barrier for beginners and nonspecialists to grasp complex phylogenetic models, including their assumptions and parameter/variable dependencies. Graphical modeling is a unifying framework that has gained in popularity in the statistical literature in recent years. The core idea is to break complex models into conditionally independent distributions. The strength lies in the comprehensibility, flexibility, and adaptability of this formalism, and the large body of computational work based on it. Graphical models are well-suited to teach statistical models, to facilitate communication among phylogeneticists and in the development of generic software for simulation and statistical inference. Here, we provide an introduction to graphical models for phylogeneticists and extend the standard graphical model representation to the realm of phylogenetics. We introduce a new graphical model component, tree plates, to capture the changing structure of the subgraph corresponding to a phylogenetic tree. We describe a range of phylogenetic models using the graphical model framework and introduce modules to simplify the representation of standard components in large and complex models. Phylogenetic model graphs can be readily used in simulation, maximum likelihood inference, and Bayesian inference using, for example, Metropolis-Hastings or Gibbs sampling of the posterior distribution. PMID:24951559

  7. The development of representation in young children.

    PubMed

    DeLoache, J S

    1989-01-01

    The research summarized here shows that young children undergo an abrupt transition in their ability to understand the relation between a scale model and a larger space. Virtually none of our 2.5-year-old subjects seemed to understand the relationship between the model and the room; almost all of the 3-year-olds did understand it. The difference seems to be that the 2.5-year-olds do not respond to the model both as a real thing and as a representation of something else. Its status as a complex, meaningful real object prevents their apprehension of its abstract relation to the room. The resistance to instruction, abrupt developmental shift, and negligible individual differences in the model task suggest the possibility of a strong maturational underpinning (Espenschade & Eckert, 1967). Further research, including a longitudinal study and cross-cultural comparisons, will be addressed to the issue of the role of experience in the development of mastery of the model task. The primary contribution of this research lies in the revelation of a hitherto undocumented abrupt developmental shift in very young children's representational flexibility--in their ability to form and coordinate multiple representations. The ability to think of one thing in two ways is an important aspect of early symbolic development. In Western cultures, where so much of a child's learning occurs via various representational media, this is a crucial step. More generally, the cognitive advance that occurs between 2.5 and 3 years of age provides a foundation for further developments in the understanding of multiple representations. PMID:2480700

  8. Probabilistic Graphical Model Representation in Phylogenetics

    PubMed Central

    Höhna, Sebastian; Heath, Tracy A.; Boussau, Bastien; Landis, Michael J.; Ronquist, Fredrik; Huelsenbeck, John P.

    2014-01-01

    Recent years have seen a rapid expansion of the model space explored in statistical phylogenetics, emphasizing the need for new approaches to statistical model representation and software development. Clear communication and representation of the chosen model is crucial for: (i) reproducibility of an analysis, (ii) model development, and (iii) software design. Moreover, a unified, clear and understandable framework for model representation lowers the barrier for beginners and nonspecialists to grasp complex phylogenetic models, including their assumptions and parameter/variable dependencies. Graphical modeling is a unifying framework that has gained in popularity in the statistical literature in recent years. The core idea is to break complex models into conditionally independent distributions. The strength lies in the comprehensibility, flexibility, and adaptability of this formalism, and the large body of computational work based on it. Graphical models are well-suited to teach statistical models, to facilitate communication among phylogeneticists and in the development of generic software for simulation and statistical inference. Here, we provide an introduction to graphical models for phylogeneticists and extend the standard graphical model representation to the realm of phylogenetics. We introduce a new graphical model component, tree plates, to capture the changing structure of the subgraph corresponding to a phylogenetic tree. We describe a range of phylogenetic models using the graphical model framework and introduce modules to simplify the representation of standard components in large and complex models. Phylogenetic model graphs can be readily used in simulation, maximum likelihood inference, and Bayesian inference using, for example, Metropolis–Hastings or Gibbs sampling of the posterior distribution. [Computation; graphical models; inference; modularization; statistical phylogenetics; tree plate.] PMID:24951559

  9. Semiclassical initial value representation for the quantum propagator in the Heisenberg interaction representation

    SciTech Connect

    Petersen, Jakob; Pollak, Eli

    2015-12-14

    One of the challenges facing on-the-fly ab initio semiclassical time evolution is the large expense needed to converge the computation. In this paper, we suggest that a significant saving in computational effort may be achieved by employing a semiclassical initial value representation (SCIVR) of the quantum propagator based on the Heisenberg interaction representation. We formulate and test numerically a modification and simplification of the previous semiclassical interaction representation of Shao and Makri [J. Chem. Phys. 113, 3681 (2000)]. The formulation is based on the wavefunction form of the semiclassical propagation instead of the operator form, and so is simpler and cheaper to implement. The semiclassical interaction representation has the advantage that the phase and prefactor vary relatively slowly as compared to the “standard” SCIVR methods. This improves its convergence properties significantly. Using a one-dimensional model system, the approximation is compared with Herman-Kluk’s frozen Gaussian and Heller’s thawed Gaussian approximations. The convergence properties of the interaction representation approach are shown to be favorable and indicate that the interaction representation is a viable way of incorporating on-the-fly force field information within a semiclassical framework.

  10. Semiclassical initial value representation for the quantum propagator in the Heisenberg interaction representation

    NASA Astrophysics Data System (ADS)

    Petersen, Jakob; Pollak, Eli

    2015-12-01

    One of the challenges facing on-the-fly ab initio semiclassical time evolution is the large expense needed to converge the computation. In this paper, we suggest that a significant saving in computational effort may be achieved by employing a semiclassical initial value representation (SCIVR) of the quantum propagator based on the Heisenberg interaction representation. We formulate and test numerically a modification and simplification of the previous semiclassical interaction representation of Shao and Makri [J. Chem. Phys. 113, 3681 (2000)]. The formulation is based on the wavefunction form of the semiclassical propagation instead of the operator form, and so is simpler and cheaper to implement. The semiclassical interaction representation has the advantage that the phase and prefactor vary relatively slowly as compared to the "standard" SCIVR methods. This improves its convergence properties significantly. Using a one-dimensional model system, the approximation is compared with Herman-Kluk's frozen Gaussian and Heller's thawed Gaussian approximations. The convergence properties of the interaction representation approach are shown to be favorable and indicate that the interaction representation is a viable way of incorporating on-the-fly force field information within a semiclassical framework.

  11. An XML Representation for Crew Procedures

    NASA Technical Reports Server (NTRS)

    Simpson, Richard C.

    2005-01-01

    NASA ensures safe operation of complex systems through the use of formally-documented procedures, which encode the operational knowledge of the system as derived from system experts. Crew members use procedure documentation on the ground for training purposes and on-board space shuttle and space station to guide their activities. Investigators at JSC are developing a new representation for procedures that is content-based (as opposed to display-based). Instead of specifying how a procedure should look on the printed page, the content-based representation will identify the components of a procedure and (more importantly) how the components are related (e.g., how the activities within a procedure are sequenced; what resources need to be available for each activity). This approach will allow different sets of rules to be created for displaying procedures on a computer screen, on a hand-held personal digital assistant (PDA), verbally, or on a printed page, and will also allow intelligent reasoning processes to automatically interpret and use procedure definitions. During his NASA fellowship, Dr. Simpson examined how various industries represent procedures (also called business processes or workflows), in areas such as manufacturing, accounting, shipping, or customer service. A useful method for designing and evaluating workflow representation languages is by determining their ability to encode various workflow patterns, which depict abstract relationships between the components of a procedure removed from the context of a specific procedure or industry. Investigators have used this type of analysis to evaluate how well-suited existing workflow representation languages are for various industries based on the workflow patterns that commonly arise across industry-specific procedures. Based on this type of analysis, it is already clear that existing workflow representations capture discrete flow of control (i.e., when one activity should start and stop based on when other

  12. Creating Multiple Representations in Algebra: All Chocolate, No Change

    ERIC Educational Resources Information Center

    Hyde, Arthur; George, Katie; Mynard, Suzanne; Hull, Christina; Watson, Sharon; Watson, Patrick

    2006-01-01

    This article describes an approach to teaching linear equations using multiple representations in a highly motivating context. Connections among representations are made explicit to enhance understanding and empower students. (Contains 4 figures.)

  13. Identifying bilingual semantic neural representations across languages

    PubMed Central

    Buchweitz, Augusto; Shinkareva, Svetlana V.; Mason, Robert A.; Mitchell, Tom M.; Just, Marcel Adam

    2015-01-01

    The goal of the study was to identify the neural representation of a noun's meaning in one language based on the neural representation of that same noun in another language. Machine learning methods were used to train classifiers to identify which individual noun bilingual participants were thinking about in one language based solely on their brain activation in the other language. The study shows reliable (p < .05) pattern-based classification accuracies for the classification of brain activity for nouns across languages. It also shows that the stable voxels used to classify the brain activation were located in areas associated with encoding information about semantic dimensions of the words in the study. The identification of the semantic trace of individual nouns from the pattern of cortical activity demonstrates the existence of a multi-voxel pattern of activation across the cortex for a single noun common to both languages in bilinguals. PMID:21978845

  14. Representations of some quantum tori Lie subalgebras

    SciTech Connect

    Jiang, Jingjing; Wang, Song

    2013-03-15

    In this paper, we define the q-analog Virasoro-like Lie subalgebras in x{sub {infinity}}=a{sub {infinity}}(b{sub {infinity}}, c{sub {infinity}}, d{sub {infinity}}). The embedding formulas into x{sub {infinity}} are introduced. Irreducible highest weight representations of A(tilde sign){sub q}, B(tilde sign){sub q}, and C(tilde sign){sub q}-series of the q-analog Virasoro-like Lie algebras in terms of vertex operators are constructed. We also construct the polynomial representations of the A(tilde sign){sub q}, B(tilde sign){sub q}, C(tilde sign){sub q}, and D(tilde sign){sub q}-series of the q-analog Virasoro-like Lie algebras.

  15. Planning Complex Sequences Using Compressed Representations

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Knight, Russell

    2009-01-01

    A method that notably includes the use of compressed representations interleaved with non-compressed (time-line) representations of a general scheduling problem has been conceived as a means of increasing, by orders of magnitude, the speeds of computations needed for scheduling complex sequences of activities that include cycles wherein subsets of the activities and/or sequences are repeated. The method was originally intended to be used in scheduling large campaigns of scientific observations by instruments aboard a spacecraft. A typical such campaign could include observations of millions of targets, many observations to be made during long repeated passes. The method would also be useful on Earth for scheduling complex sequences of activities that include cycles.

  16. Acuity of mental representations of pitch.

    PubMed

    Janata, Petr

    2012-04-01

    Singing in one's mind or forming expectations about upcoming notes both require that mental images of one or more pitches will be generated. As with other musical abilities, the acuity with which such images are formed might be expected to vary across individuals and may depend on musical training. Results from several behavioral tasks involving intonation judgments indicate that multiple memory systems contribute to the formation of accurate mental images for pitch, and that the functionality of each is affected by musical training. Electrophysiological measures indicate that the ability to form accurate mental images is associated with greater engagement of auditory areas and associated error-detection circuitry when listeners imagine ascending scales and make intonation judgments about target notes. A view of auditory mental images is espoused in which unified mental image representations are distributed across multiple brain areas. Each brain area helps shape the acuity of the unified representation based on current behavioral demands and past experience. PMID:22524362

  17. Deep learning of orthographic representations in baboons.

    PubMed

    Hannagan, Thomas; Ziegler, Johannes C; Dufau, Stéphane; Fagot, Joël; Grainger, Jonathan

    2014-01-01

    What is the origin of our ability to learn orthographic knowledge? We use deep convolutional networks to emulate the primate's ventral visual stream and explore the recent finding that baboons can be trained to discriminate English words from nonwords. The networks were exposed to the exact same sequence of stimuli and reinforcement signals as the baboons in the experiment, and learned to map real visual inputs (pixels) of letter strings onto binary word/nonword responses. We show that the networks' highest levels of representations were indeed sensitive to letter combinations as postulated in our previous research. The model also captured the key empirical findings, such as generalization to novel words, along with some intriguing inter-individual differences. The present work shows the merits of deep learning networks that can simulate the whole processing chain all the way from the visual input to the response while allowing researchers to analyze the complex representations that emerge during the learning process. PMID:24416300

  18. [Social representations of elders' quality of life].

    PubMed

    Silva, Luípa Michele; Silva, Antonia Oliveira; Tura, Luiz Fernando Rangel; Moreira, Maria Adelaide Silva Paredes; Rodrigues, Rosalina Aparecida Partezani; Marques, Maria do Céu

    2012-03-01

    This study aimed to identify elders' social representations of quality of life. This is an exploratory study with a sample of 240 elders, of both sexes. For data collection we used a Free Association Test with Words, using the inductive stimulus 'quality of life" and sociodemographic variables. The interviews were analyzed with the software Alceste. Of the 240 studied eslders, 167 were women, with the dominant age from 60 to 69 years, income between two and three minimum wages, most of the married and with catholicism as the predominant religion. The results from Alceste pointed towards seven hierarchical classes: accessibility, work, activity, support affection, care and interactions. Social representations of quality of life by elders can support professionals in understanding the adhesion to preventive practices for the elderly and in strengthening policies directed to this population. PMID:22737803

  19. Deep Learning of Orthographic Representations in Baboons

    PubMed Central

    Hannagan, Thomas; Ziegler, Johannes C.; Dufau, Stéphane; Fagot, Joël; Grainger, Jonathan

    2014-01-01

    What is the origin of our ability to learn orthographic knowledge? We use deep convolutional networks to emulate the primate's ventral visual stream and explore the recent finding that baboons can be trained to discriminate English words from nonwords [1]. The networks were exposed to the exact same sequence of stimuli and reinforcement signals as the baboons in the experiment, and learned to map real visual inputs (pixels) of letter strings onto binary word/nonword responses. We show that the networks' highest levels of representations were indeed sensitive to letter combinations as postulated in our previous research. The model also captured the key empirical findings, such as generalization to novel words, along with some intriguing inter-individual differences. The present work shows the merits of deep learning networks that can simulate the whole processing chain all the way from the visual input to the response while allowing researchers to analyze the complex representations that emerge during the learning process. PMID:24416300

  20. Symbolic representation of number in chimpanzees.

    PubMed

    Matsuzawa, Tetsuro

    2009-02-01

    This paper aims to summarize the existing evidence for the symbolic representation of number in chimpanzees. Chimpanzees can represent, to some extent, both the cardinal and the ordinal aspect of number. Through the medium of Arabic numerals we compared working memory in humans and chimpanzees using the same apparatus and following the same procedure. Three young chimpanzees outperformed human adults in memorizing briefly presented numerals. However, we found that chimpanzees were less proficient at a variety of other cognitive tasks including imitation, cross-modal matching, symmetry of symbols and referents, and one-to-one correspondence. In sum, chimpanzees do not possess human-like capabilities for representation at an abstract level. The present paper will discuss the constraints of the number concept in chimpanzees, and illuminate some unique features of human cognition. PMID:19447029

  1. Process and representation in graphical displays

    NASA Technical Reports Server (NTRS)

    Gillan, Douglas J.; Lewis, Robert; Rudisill, Marianne

    1993-01-01

    Our initial model of graphic comprehension has focused on statistical graphs. Like other models of human-computer interaction, models of graphical comprehension can be used by human-computer interface designers and developers to create interfaces that present information in an efficient and usable manner. Our investigation of graph comprehension addresses two primary questions: how do people represent the information contained in a data graph?; and how do they process information from the graph? The topics of focus for graphic representation concern the features into which people decompose a graph and the representations of the graph in memory. The issue of processing can be further analyzed as two questions: what overall processing strategies do people use?; and what are the specific processing skills required?

  2. Complete Gabor transformation for signal representation.

    PubMed

    Yao, J

    1993-01-01

    Properties of the Gabor transformation used for image representation are discussed. The properties can be expressed in matrix notation, and the complete Gabor coefficients can be found by multiplying the inverse of the Gabor (1946) matrix and the signal vector. The Gabor matrix can be decomposed into the product of a sparse constant complex matrix and another sparse matrix that depends only on the window function. A fast algorithm is suggested to compute the inverse of the window function matrix, enabling discrete signals to be transformed into generalized nonorthogonal Gabor representations efficiently. A comparison is made between this method and the analytical method. The relation between the window function matrix and the biorthogonal functions is demonstrated. A numerical computation method for the biorthogonal functions is proposed. PMID:18296205

  3. Accurate metacognition for visual sensory memory representations.

    PubMed

    Vandenbroucke, Annelinde R E; Sligte, Ilja G; Barrett, Adam B; Seth, Anil K; Fahrenfort, Johannes J; Lamme, Victor A F

    2014-04-01

    The capacity to attend to multiple objects in the visual field is limited. However, introspectively, people feel that they see the whole visual world at once. Some scholars suggest that this introspective feeling is based on short-lived sensory memory representations, whereas others argue that the feeling of seeing more than can be attended to is illusory. Here, we investigated this phenomenon by combining objective memory performance with subjective confidence ratings during a change-detection task. This allowed us to compute a measure of metacognition--the degree of knowledge that subjects have about the correctness of their decisions--for different stages of memory. We show that subjects store more objects in sensory memory than they can attend to but, at the same time, have similar metacognition for sensory memory and working memory representations. This suggests that these subjective impressions are not an illusion but accurate reflections of the richness of visual perception. PMID:24549293

  4. Adjoints and Low-rank Covariance Representation

    NASA Technical Reports Server (NTRS)

    Tippett, Michael K.; Cohn, Stephen E.

    2000-01-01

    Quantitative measures of the uncertainty of Earth System estimates can be as important as the estimates themselves. Second moments of estimation errors are described by the covariance matrix, whose direct calculation is impractical when the number of degrees of freedom of the system state is large. Ensemble and reduced-state approaches to prediction and data assimilation replace full estimation error covariance matrices by low-rank approximations. The appropriateness of such approximations depends on the spectrum of the full error covariance matrix, whose calculation is also often impractical. Here we examine the situation where the error covariance is a linear transformation of a forcing error covariance. We use operator norms and adjoints to relate the appropriateness of low-rank representations to the conditioning of this transformation. The analysis is used to investigate low-rank representations of the steady-state response to random forcing of an idealized discrete-time dynamical system.

  5. Composite wavelet representations for reconstruction of missing data

    NASA Astrophysics Data System (ADS)

    Czaja, Wojciech; Dobrosotskaya, Julia; Manning, Benjamin

    2013-05-01

    We shall introduce a novel methodology for data reconstruction and recovery, based on composite wavelet representations. These representations include shearlets and crystallographic wavelets, among others, and they allow for an increased directional sensitivity in comparison with the standard multiscale techniques. Our new approach allows us to recover missing data, due to sparsity of composite wavelet representations, especially when compared to inpainting algorithms induced by traditional wavelet representations, and also due to the flexibility of our variational approach.

  6. Magnetic monopole in the loop representation

    SciTech Connect

    Leal, Lorenzo; Lopez, Alexander

    2006-01-15

    We quantize, within the Loop Representation formalism, the electromagnetic field in the presence of a static magnetic pole. It is found that the loop-dependent physical wave functionals of the quantum Maxwell theory become multivalued, through a topological phase factor depending on the solid angle subtended at the monopole by a surface bounded by the loop. It is discussed how this fact generalizes what occurs in ordinary quantum mechanics in multiply connected spaces.

  7. Robust kernel collaborative representation for face recognition

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Wang, Xiaohui; Ma, Yanbo; Jiang, Yuzheng; Zhu, Yinghui; Jin, Zhong

    2015-05-01

    One of the greatest challenges of representation-based face recognition is that the training samples are usually insufficient. In other words, the training set usually does not include enough samples to show varieties of high-dimensional face images caused by illuminations, facial expressions, and postures. When the test sample is significantly different from the training samples of the same subject, the recognition performance will be sharply reduced. We propose a robust kernel collaborative representation based on virtual samples for face recognition. We think that the virtual training set conveys some reasonable and possible variations of the original training samples. Hence, we design a new object function to more closely match the representation coefficients generated from the original and virtual training sets. In order to further improve the robustness, we implement the corresponding representation-based face recognition in kernel space. It is noteworthy that any kind of virtual training samples can be used in our method. We use noised face images to obtain virtual face samples. The noise can be approximately viewed as a reflection of the varieties of illuminations, facial expressions, and postures. Our work is a simple and feasible way to obtain virtual face samples to impose Gaussian noise (and other types of noise) specifically to the original training samples to obtain possible variations of the original samples. Experimental results on the FERET, Georgia Tech, and ORL face databases show that the proposed method is more robust than two state-of-the-art face recognition methods, such as CRC and Kernel CRC.

  8. Bayesian learning of sparse multiscale image representations.

    PubMed

    Hughes, James Michael; Rockmore, Daniel N; Wang, Yang

    2013-12-01

    Multiscale representations of images have become a standard tool in image analysis. Such representations offer a number of advantages over fixed-scale methods, including the potential for improved performance in denoising, compression, and the ability to represent distinct but complementary information that exists at various scales. A variety of multiresolution transforms exist, including both orthogonal decompositions such as wavelets as well as nonorthogonal, overcomplete representations. Recently, techniques for finding adaptive, sparse representations have yielded state-of-the-art results when applied to traditional image processing problems. Attempts at developing multiscale versions of these so-called dictionary learning models have yielded modest but encouraging results. However, none of these techniques has sought to combine a rigorous statistical formulation of the multiscale dictionary learning problem and the ability to share atoms across scales. We present a model for multiscale dictionary learning that overcomes some of the drawbacks of previous approaches by first decomposing an input into a pyramid of distinct frequency bands using a recursive filtering scheme, after which we perform dictionary learning and sparse coding on the individual levels of the resulting pyramid. The associated image model allows us to use a single set of adapted dictionary atoms that is shared--and learned--across all scales in the model. The underlying statistical model of our proposed method is fully Bayesian and allows for efficient inference of parameters, including the level of additive noise for denoising applications. We apply the proposed model to several common image processing problems including non-Gaussian and nonstationary denoising of real-world color images. PMID:24002002

  9. A Hybrid Constraint Representation and Reasoning Framework

    NASA Technical Reports Server (NTRS)

    Golden, Keith; Pang, Wanlin

    2004-01-01

    In this paper, we introduce JNET, a novel constraint representation and reasoning framework that supports procedural constraints and constraint attachments, providing a flexible way of integrating the constraint system with a runtime software environment and improving its applicability. We describe how JNET is applied to a real-world problem - NASA's Earth-science data processing domain, and demonstrate how JNET can be extended, without any knowledge of how it is implemented, to meet the growing demands of real-world applications.

  10. Shape Representation And Recognition With Depth Information

    NASA Astrophysics Data System (ADS)

    Gorman, John W.; Mitchell, O. Robert

    1988-02-01

    Many global shape recognition techniques, such as moments and Fourier Descriptors, are used almost exclusively with two-dimensional images. It would be desirable to extend these global shape recognition concepts to three dimensional images. Specifically, the concepts associated with Fourier Descriptors will be extended to both three dimensional object representation and recognition and the representation and recognition of objects which are described by depth data. With Fourier Descriptors, two dimensional shape boundaries are described in terms of a set of complex sinusoidal basis functions. Extending this concept to three dimensions, the surface of a shape will be described in terms of a set of three .dimensional basis functions. The basis functions which will be used are known as spherical harmonics. Spherical harmonics can be used to describe a function on the surface of the unit sphere. In this application, the function on the unit sphere will describe the shape to be represented. The representation presented here is restricted to the class of objects for which each ray from the origin intersects the surface of the object only once. Basic definitions and properties of spherical harmonics will be discussed. A distance measure for shape discrimination will be derived as a function of the spherical harmonic coefficients for two shapes. The question of representation of objects described by depth data will then be addressed. A functional description for the objects will be introduced, along with methods of normalizing the spherical harmonic coefficients for scale, translation, and orientation so that meaningful library comparisons might be possible. Classification results obtained with a set of simple objects will be discussed.

  11. Spatial representations of words and nonwords.

    PubMed

    Nicoletti, R; Umiltà, C; Mapelli, D

    1992-06-01

    The first two experiments investigated whether the representations of words, besides being unitary, are also spatial in nature. Subjects were required to search for target letters in either five-letter words or five-letter nonwords. They were instructed to press the right-side key for one target and the left-side key for the other target. The center item of the letter string was always at fixation. Targets appeared one at a time, located at the second (left side) or the fourth (right side) position within the letter string. The results showed that: a) responses to targets within words were faster than responses to targets within nonwords (the word-superiority effect); b) responses to compatible stimulus-response pairings were faster than responses to incompatible stimulus-response pairings (the spatial compatibility, or, more precisely, the Simon effect); and c) in Experiment 2, left-side targets were responded to faster than right-side targets within nonwords (the left-right scanning effect). It was concluded that representations of both words and nonwords are spatial in nature. Experiment 3 was aimed at testing whether the spatial layout of the representations of words is always along the left-right horizontal dimension, regardless of the topographic transformation of the stimulus. The same words and nonwords used in the previous experiments were shown vertically and the subjects were required to make left-right discriminative responses to upper and lower target letters. The results showed the word-superiority effect but no spatial compatibility effects. It was concluded that the representation of a vertically presented word is vertically arranged. PMID:1499303

  12. Neonatal Atlas Construction Using Sparse Representation

    PubMed Central

    Shi, Feng; Wang, Li; Wu, Guorong; Li, Gang; Gilmore, John H.; Lin, Weili; Shen, Dinggang

    2014-01-01

    Atlas construction generally includes first an image registration step to normalize all images into a common space and then an atlas building step to fuse the information from all the aligned images. Although numerous atlas construction studies have been performed to improve the accuracy of the image registration step, unweighted or simply weighted average is often used in the atlas building step. In this article, we propose a novel patch-based sparse representation method for atlas construction after all images have been registered into the common space. By taking advantage of local sparse representation, more anatomical details can be recovered in the built atlas. To make the anatomical structures spatially smooth in the atlas, the anatomical feature constraints on group structure of representations and also the overlapping of neighboring patches are imposed to ensure the anatomical consistency between neighboring patches. The proposed method has been applied to 73 neonatal MR images with poor spatial resolution and low tissue contrast, for constructing a neonatal brain atlas with sharp anatomical details. Experimental results demonstrate that the proposed method can significantly enhance the quality of the constructed atlas by discovering more anatomical details especially in the highly convoluted cortical regions. The resulting atlas demonstrates superior performance of our atlas when applied to spatially normalizing three different neonatal datasets, compared with other start-of-the-art neonatal brain atlases. PMID:24638883

  13. Generative Representations for Evolving Families of Designs

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2003-01-01

    Since typical evolutionary design systems encode only a single artifact with each individual, each time the objective changes a new set of individuals must be evolved. When this objective varies in a way that can be parameterized, a more general method is to use a representation in which a single individual encodes an entire class of artifacts. In addition to saving time by preventing the need for multiple evolutionary runs, the evolution of parameter-controlled designs can create families of artifacts with the same style and a reuse of parts between members of the family. In this paper an evolutionary design system is described which uses a generative representation to encode families of designs. Because a generative representation is an algorithmic encoding of a design, its input parameters are a way to control aspects of the design it generates. By evaluating individuals multiple times with different input parameters the evolutionary design system creates individuals in which the input parameter controls specific aspects of a design. This system is demonstrated on two design substrates: neural-networks which solve the 3/5/7-parity problem and three-dimensional tables of varying heights.

  14. Formalization and representation of expert systems

    SciTech Connect

    Tausner, M.R.

    1986-01-01

    Based on a critical analysis of the canonical forms of expert systems, definitions of classical forward-chaining production rule-based expert systems and classical backward-chaining production rule based expert systems are isolated as the fundamental basic definitions of an expert system. Two representation theorems are presented for the two fundamental types of expert systems defined. Both the classical forward-chaining production rule based expert systems and classical backward chaining production rule based expert systems are shown to be representable as type 3 languages (finite state automata). The pragmatic usefulness of the finite state representation of an expert system is established in the design of a multilevel expert system for general systems problems solving. A type 3 language is used to encapsulate the knowledge base and reasoning strategies of the front-end of the expert system, thus representing the front-end as a deterministic finite automation. This provides a new approach to the problem of interfacing multilevel expert systems.

  15. Quaternionic representation of the genetic code.

    PubMed

    Carlevaro, C Manuel; Irastorza, Ramiro M; Vericat, Fernando

    2016-03-01

    A heuristic diagram of the evolution of the standard genetic code is presented. It incorporates, in a way that resembles the energy levels of an atom, the physical notion of broken symmetry and it is consistent with original ideas by Crick on the origin and evolution of the code as well as with the chronological order of appearance of the amino acids along the evolution as inferred from work that mixtures known experimental results with theoretical speculations. Suggested by the diagram we propose a Hamilton quaternions based mathematical representation of the code as it stands now-a-days. The central object in the description is a codon function that assigns to each amino acid an integer quaternion in such a way that the observed code degeneration is preserved. We emphasize the advantages of a quaternionic representation of amino acids taking as an example the folding of proteins. With this aim we propose an algorithm to go from the quaternions sequence to the protein three dimensional structure which can be compared with the corresponding experimental one stored at the Protein Data Bank. In our criterion the mathematical representation of the genetic code in terms of quaternions merits to be taken into account because it describes not only most of the known properties of the genetic code but also opens new perspectives that are mainly derived from the close relationship between quaternions and rotations. PMID:26751396

  16. Local-time representation of path integrals.

    PubMed

    Jizba, Petr; Zatloukal, Václav

    2015-12-01

    We derive a local-time path-integral representation for a generic one-dimensional time-independent system. In particular, we show how to rephrase the matrix elements of the Bloch density matrix as a path integral over x-dependent local-time profiles. The latter quantify the time that the sample paths x(t) in the Feynman path integral spend in the vicinity of an arbitrary point x. Generalization of the local-time representation that includes arbitrary functionals of the local time is also provided. We argue that the results obtained represent a powerful alternative to the traditional Feynman-Kac formula, particularly in the high- and low-temperature regimes. To illustrate this point, we apply our local-time representation to analyze the asymptotic behavior of the Bloch density matrix at low temperatures. Further salient issues, such as connections with the Sturm-Liouville theory and the Rayleigh-Ritz variational principle, are also discussed. PMID:26764662

  17. Document image representation using XML technologies

    NASA Astrophysics Data System (ADS)

    El-Kwae, Essam A.; Atmakuri, Kusuma H.

    2001-12-01

    Electronic documents have gained wide acceptance due to the ease of editing and sharing of information. However, paper documents are still widely used in many environments. Moving into a paperless and distributed office has become a major goal for document image research. A new approach for form document representation is presented. This approach allows for electronic document sharing over the World Wide Web (WWW) using Extensible Markup Language (XML) technologies. Each document is mapped into three different views, an XML view to represent the preprinted and filled-in data, an XSL (Extensible style Sheets) view to represent the structure of the document, and a DTD (Document Type Definition) view to represent the document grammar and field constraints. The XML and XSL views are generated from a document template, either automatically using image processing techniques, or semi-automatically with minimal user interaction. The DTD representation may be fixed for general documents or may be generated semi-automatically by mining a number of filled-in document examples. Document templates need to be entered once to create the proposed representation. Afterwards, documents may be displayed, updated, or shared over the web. The merits of this approach are demonstrated using a number of examples of widely used forms.

  18. Aerial Scene Recognition using Efficient Sparse Representation

    SciTech Connect

    Cheriyadat, Anil M

    2012-01-01

    Advanced scene recognition systems for processing large volumes of high-resolution aerial image data are in great demand today. However, automated scene recognition remains a challenging problem. Efficient encoding and representation of spatial and structural patterns in the imagery are key in developing automated scene recognition algorithms. We describe an image representation approach that uses simple and computationally efficient sparse code computation to generate accurate features capable of producing excellent classification performance using linear SVM kernels. Our method exploits unlabeled low-level image feature measurements to learn a set of basis vectors. We project the low-level features onto the basis vectors and use simple soft threshold activation function to derive the sparse features. The proposed technique generates sparse features at a significantly lower computational cost than other methods~\\cite{Yang10, newsam11}, yet it produces comparable or better classification accuracy. We apply our technique to high-resolution aerial image datasets to quantify the aerial scene classification performance. We demonstrate that the dense feature extraction and representation methods are highly effective for automatic large-facility detection on wide area high-resolution aerial imagery.

  19. Properties of gray and binary representations.

    PubMed

    Rowe, Jonathan; Whitley, Darrell; Barbulescu, Laura; Watson, Jean-Paul

    2004-01-01

    Representations are formalized as encodings that map the search space to the vertex set of a graph. We define the notion of bit equivalent encodings and show that for such encodings the corresponding Walsh coefficients are also conserved. We focus on Gray codes as particular types of encoding and present a review of properties related to the use of Gray codes. Gray codes are widely used in conjunction with genetic algorithms and bit-climbing algorithms for parameter optimization problems. We present new convergence proofs for a special class of unimodal functions; the proofs show that a steepest ascent bit climber using any reflected Gray code representation reaches the global optimum in a number of steps that is linear with respect to the encoding size. There are in fact many different Gray codes. Shifting is defined as a mechanism for dynamically switching from one Gray code representation to another in order to escape local optima. Theoretical results that substantially improve our understanding of the Gray codes and the shifting mechanism are presented. New proofs also shed light on the number of unique Gray code neighborhoods accessible via shifting and on how neighborhood structure changes during shifting. We show that shifting can improve the performance of both a local search algorithm as well as one of the best genetic algorithms currently available. PMID:15096305

  20. Are face representations depth cue invariant?

    PubMed

    Dehmoobadsharifabadi, Armita; Farivar, Reza

    2016-06-01

    The visual system can process three-dimensional depth cues defining surfaces of objects, but it is unclear whether such information contributes to complex object recognition, including face recognition. The processing of different depth cues involves both dorsal and ventral visual pathways. We investigated whether facial surfaces defined by individual depth cues resulted in meaningful face representations-representations that maintain the relationship between the population of faces as defined in a multidimensional face space. We measured face identity aftereffects for facial surfaces defined by individual depth cues (Experiments 1 and 2) and tested whether the aftereffect transfers across depth cues (Experiments 3 and 4). Facial surfaces and their morphs to the average face were defined purely by one of shading, texture, motion, or binocular disparity. We obtained identification thresholds for matched (matched identity between adapting and test stimuli), non-matched (non-matched identity between adapting and test stimuli), and no-adaptation (showing only the test stimuli) conditions for each cue and across different depth cues. We found robust face identity aftereffect in both experiments. Our results suggest that depth cues do contribute to forming meaningful face representations that are depth cue invariant. Depth cue invariance would require integration of information across different areas and different pathways for object recognition, and this in turn has important implications for cortical models of visual object recognition. PMID:27271993

  1. Incidental statistical summary representation over time.

    PubMed

    Oriet, Chris; Hozempa, Kadie

    2016-01-01

    Information taken in by the human visual system allows individuals to form statistical representations of sets of items. One's knowledge of natural categories includes statistical information, such as average size of category members and the upper and lower boundaries of the set. Previous research suggests that when subjects attend to a particular dimension of a set of items presented over an extended duration, they quickly learn about the central tendency of the set. However, it is unclear whether such learning can occur incidentally, when subjects are not attending to the relevant dimension of the set. The present study explored whether subjects could reproduce global statistical properties of a set presented over an extended duration when oriented to task-irrelevant properties of the set. Subjects were tested for their memory of its mean, its smallest and largest exemplars, the direction of its skew, and the relative distribution of the items. Subjects were able to accurately recall the average size circle, as well as the upper and lower boundaries of a set of 4,200 circles displayed over an extended period. This suggests that even without intending to do so, they were encoding and updating a statistical summary representation of a task-irrelevant attribute of the circles over time. Such incidental encoding of statistical properties of sets is thus a plausible mechanism for establishing a representation of typicality in category membership. PMID:26830709

  2. The representation of uniform motion in vision.

    PubMed

    Swanston, M T; Wade, N J; Day, R H

    1987-01-01

    For veridical detection of object motion any moving detecting system must allocate motion appropriately between itself and objects in space. A model for such allocation is developed for simplified situations (points of light in uniform motion in a frontoparallel plane). It is proposed that motion of objects is registered and represented successively at four levels within frames of reference that are defined by the detectors themselves or by their movements. The four levels are referred to as retinocentric, orbitocentric, egocentric, and geocentric. Thus the retinocentric signal is combined with that for eye rotation to give an orbitocentric signal, and the left and right orbitocentric signals are combined to give an egocentric representation. Up to the egocentric level, motion representation is angular rather than three-dimensional. The egocentric signal is combined with signals for head and body movement and for egocentric distance to give a geocentric representation. It is argued that although motion perception is always geocentric, relevant registrations also occur at the three earlier levels. The model is applied to various veridical and nonveridical motion phenomena. PMID:3684477

  3. Grid-cell representations in mental simulation

    PubMed Central

    Bellmund, Jacob LS; Deuker, Lorena; Navarro Schröder, Tobias; Doeller, Christian F

    2016-01-01

    Anticipating the future is a key motif of the brain, possibly supported by mental simulation of upcoming events. Rodent single-cell recordings suggest the ability of spatially tuned cells to represent subsequent locations. Grid-like representations have been observed in the human entorhinal cortex during virtual and imagined navigation. However, hitherto it remains unknown if grid-like representations contribute to mental simulation in the absence of imagined movement. Participants imagined directions between building locations in a large-scale virtual-reality city while undergoing fMRI without re-exposure to the environment. Using multi-voxel pattern analysis, we provide evidence for representations of absolute imagined direction at a resolution of 30° in the parahippocampal gyrus, consistent with the head-direction system. Furthermore, we capitalize on the six-fold rotational symmetry of grid-cell firing to demonstrate a 60° periodic pattern-similarity structure in the entorhinal cortex. Our findings imply a role of the entorhinal grid-system in mental simulation and future thinking beyond spatial navigation. DOI: http://dx.doi.org/10.7554/eLife.17089.001 PMID:27572056

  4. On state representations of nonlinear implicit systems

    NASA Astrophysics Data System (ADS)

    Pereira da Silva, Paulo Sergio; Batista, Simone

    2010-03-01

    This work considers a semi-implicit system Δ, that is, a pair (S, y), where S is an explicit system described by a state representation ? , where x(t) ∈ ℝ n and u(t) ∈ ℝ m , which is subject to a set of algebraic constraints y(t) = h(t, x(t), u(t)) = 0, where y(t) ∈ ℝ l . An input candidate is a set of functions v = (v 1, …, v s ), which may depend on time t, on x, and on u and its derivatives up to a finite order. The problem of finding a (local) proper state representation ż = g(t, z, v) with input v for the implicit system Δ is studied in this article. The main result shows necessary and sufficient conditions for the solution of this problem, under mild assumptions on the class of admissible state representations of Δ. These solvability conditions rely on an integrability test that is computed from the explicit system S. The approach of this article is the infinite-dimensional differential geometric setting of Fliess, Lévine, Martin, and Rouchon (1999) ('A Lie-Bäcklund Approach to Equivalence and Flatness of Nonlinear Systems', IEEE Transactions on Automatic Control, 44(5), (922-937)).

  5. Grid-cell representations in mental simulation.

    PubMed

    Bellmund, Jacob Ls; Deuker, Lorena; Navarro Schröder, Tobias; Doeller, Christian F

    2016-01-01

    Anticipating the future is a key motif of the brain, possibly supported by mental simulation of upcoming events. Rodent single-cell recordings suggest the ability of spatially tuned cells to represent subsequent locations. Grid-like representations have been observed in the human entorhinal cortex during virtual and imagined navigation. However, hitherto it remains unknown if grid-like representations contribute to mental simulation in the absence of imagined movement. Participants imagined directions between building locations in a large-scale virtual-reality city while undergoing fMRI without re-exposure to the environment. Using multi-voxel pattern analysis, we provide evidence for representations of absolute imagined direction at a resolution of 30° in the parahippocampal gyrus, consistent with the head-direction system. Furthermore, we capitalize on the six-fold rotational symmetry of grid-cell firing to demonstrate a 60° periodic pattern-similarity structure in the entorhinal cortex. Our findings imply a role of the entorhinal grid-system in mental simulation and future thinking beyond spatial navigation. PMID:27572056

  6. The Ability of Young Korean Children to Use Spatial Representations

    ERIC Educational Resources Information Center

    Kim, Minsung; Bednarz, Robert; Kim, Jaeyil

    2012-01-01

    The National Research Council emphasizes using tools of representation as an essential element of spatial thinking. However, it is debatable at what age the use of spatial representation for spatial thinking skills should begin. This study investigated whether young Korean children possess the potential to understand map-like representation using…

  7. Community Racial Segregation, Electoral Structure, and Minority Representation.

    ERIC Educational Resources Information Center

    Vedlitz, Arnold; Johnson, Charles A.

    1982-01-01

    Community electoral structures and segregation levels affect minority representation. Single-member district electorate systems provide significantly more favorable minority representation levels in segregated communities. In nonsegregated cities type of election system makes little difference in the equality of minority representation. (Author/AM)

  8. Squeezing, Striking, and Vocalizing: Is Number Representation Fundamentally Spatial?

    ERIC Educational Resources Information Center

    Nunez, Rafael; Doan, D.; Nikoulina, Anastasia

    2011-01-01

    Numbers are fundamental entities in mathematics, but their cognitive bases are unclear. Abundant research points to linear space as a natural grounding for number representation. But, is number representation fundamentally spatial? We disentangle number representation from standard number-to-line reporting methods, and compare numerical…

  9. 20 CFR 801.401 - Representation before the Board.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Representation before the Board. 801.401 Section 801.401 Employees' Benefits BENEFITS REVIEW BOARD, DEPARTMENT OF LABOR ESTABLISHMENT AND OPERATION OF THE BOARD Representation § 801.401 Representation before the Board. On any issues...

  10. 40 CFR 96.13 - Account certificate of representation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Account certificate of representation... IMPLEMENTATION PLANS NOX Authorized Account Representative for NOX Budget Sources § 96.13 Account certificate of representation. (a) A complete account certificate of representation for a NOX authorized account...

  11. 40 CFR 97.13 - Account certificate of representation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Account certificate of representation... Authorized Account Representative for NOX Budget Sources § 97.13 Account certificate of representation. (a) A complete account certificate of representation for a NOX authorized account representative or an...

  12. Single or Dual Representations for Reading and Spelling?

    ERIC Educational Resources Information Center

    Holmes, Virginia M.; Babauta, Mariko L.

    2005-01-01

    Neuropsychological models postulate that the memory representation acquired for use in reading words is separate from the one acquired for use in spelling, while developmental models assume that the same representation is developed for access in both reading and spelling. The dual-representation model contends that there is often more precise…

  13. Technology Focus: Multi-Representational Approaches to Equation Solving

    ERIC Educational Resources Information Center

    Garofalo, Joe; Trinter, Christine

    2009-01-01

    Most mathematical functions can be represented in numerous ways. The main representations typically addressed in school, often referred to as "the big three," are graphical, algebraic, and numerical representations, but there are others as well (e.g., diagrams, words, simulations). These different types of representations "often illuminate…

  14. 20 CFR 501.9 - Representation; appearances and fees.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Representation; appearances and fees. 501.9 Section 501.9 Employees' Benefits EMPLOYEES' COMPENSATION APPEALS BOARD, DEPARTMENT OF LABOR RULES OF PROCEDURE § 501.9 Representation; appearances and fees. (a) Representation. In any proceeding before the Board, an Appellant may appear in person...

  15. 15 CFR 2009.1 - Information required in representation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... 2009.1 Section 2009.1 Commerce and Foreign Trade Regulations Relating to Foreign Trade Agreements... TRADE AGREEMENTS ACT OF 1979 § 2009.1 Information required in representation. (a) Each representation submitted under section 422 should state clearly on the first page that the representation is a request...

  16. 15 CFR 2009.1 - Information required in representation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... 2009.1 Section 2009.1 Commerce and Foreign Trade Regulations Relating to Foreign Trade Agreements... TRADE AGREEMENTS ACT OF 1979 § 2009.1 Information required in representation. (a) Each representation submitted under section 422 should state clearly on the first page that the representation is a request...

  17. 15 CFR 2009.1 - Information required in representation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... 2009.1 Section 2009.1 Commerce and Foreign Trade Regulations Relating to Foreign Trade Agreements... TRADE AGREEMENTS ACT OF 1979 § 2009.1 Information required in representation. (a) Each representation submitted under section 422 should state clearly on the first page that the representation is a request...

  18. 15 CFR 2009.1 - Information required in representation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... 2009.1 Section 2009.1 Commerce and Foreign Trade Regulations Relating to Foreign Trade Agreements... TRADE AGREEMENTS ACT OF 1979 § 2009.1 Information required in representation. (a) Each representation submitted under section 422 should state clearly on the first page that the representation is a request...

  19. 40 CFR 72.24 - Certificate of representation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Certificate of representation. 72.24 Section 72.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Designated Representative § 72.24 Certificate of representation. (a) A complete certificate of representation for...

  20. Role of Multiple Representations in Physics Problem Solving

    ERIC Educational Resources Information Center

    Maries, Alexandru

    2013-01-01

    This thesis explores the role of multiple representations in introductory physics students' problem solving performance through several investigations. Representations can help students focus on the conceptual aspects of physics and play a major role in effective problem solving. Diagrammatic representations can play a particularly important role…

  1. Cognitive Dissonance as an Instructional Tool for Understanding Chemical Representations

    ERIC Educational Resources Information Center

    Corradi, David; Clarebout, Geraldine; Elen, Jan

    2015-01-01

    Previous research on multiple external representations (MER) indicates that sequencing representations (compared with presenting them as a whole) can, in some cases, increase conceptual understanding if there is interference between internal and external representations. We tested this mechanism by sequencing different combinations of scientific…

  2. External Representations for Data Distributions: In Search of Cognitive Fit

    ERIC Educational Resources Information Center

    Lem, Stephanie; Onghana, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2013-01-01

    Data distributions can be represented using different external representations, such as histograms and boxplots. Although the role of external representations has been extensively studied in mathematics, this is less the case in statistics. This study helps to fill this gap by systematically varying the representation that accompanies a task…

  3. Models as Feedback: Developing Representational Competence in Chemistry

    ERIC Educational Resources Information Center

    Padalkar, Shamin; Hegarty, Mary

    2015-01-01

    Spatial information in science is often expressed through representations such as diagrams and models. Learning the strengths and limitations of these representations and how to relate them are important aspects of developing scientific understanding, referred to as "representational competence." Diagram translation is particularly…

  4. Prosodic Phonological Representations Early in Visual Word Recognition

    ERIC Educational Resources Information Center

    Ashby, Jane; Martin, Andrea E.

    2008-01-01

    Two experiments examined the nature of the phonological representations used during visual word recognition. We tested whether a minimality constraint (R. Frost, 1998) limits the complexity of early representations to a simple string of phonemes. Alternatively, readers might activate elaborated representations that include prosodic syllable…

  5. Using Computer-Assisted Multiple Representations in Learning Geometry Proofs

    ERIC Educational Resources Information Center

    Wong, Wing-Kwong; Yin, Sheng-Kai; Yang, Hsi-Hsun; Cheng, Ying-Hao

    2011-01-01

    Geometry theorem proving involves skills that are difficult to learn. Instead of working with abstract and complicated representations, students might start with concrete, graphical representations. A proof tree is a graphical representation of a formal proof, with each node representing a proposition or given conditions. A computer-assisted…

  6. 46 CFR 502.410 - Representation of parties.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Alternative Dispute Resolution § 502.410 Representation of parties. (a) The provisions of § 502.21 apply to the representation of parties in dispute resolution proceedings, as do the provisions of § 502.27 regarding the representation of parties by nonattorneys. (b) A neutral in a dispute resolution...

  7. 46 CFR 502.410 - Representation of parties.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Alternative Dispute Resolution § 502.410 Representation of parties. (a) The provisions of § 502.21 apply to the representation of parties in dispute resolution proceedings, as do the provisions of § 502.27 regarding the representation of parties by nonattorneys. (b) A neutral in a dispute resolution...

  8. A Rational Analysis of the Acquisition of Multisensory Representations

    ERIC Educational Resources Information Center

    Yildirim, Ilker; Jacobs, Robert A.

    2012-01-01

    How do people learn multisensory, or amodal, representations, and what consequences do these representations have for perceptual performance? We address this question by performing a rational analysis of the problem of learning multisensory representations. This analysis makes use of a Bayesian nonparametric model that acquires latent multisensory…

  9. Learning Through Constructing Representations in Science: A framework of representational construction affordances

    NASA Astrophysics Data System (ADS)

    Prain, Vaughan; Tytler, Russell

    2012-11-01

    Compared with research on the role of student engagement with expert representations in learning science, investigation of the use and theoretical justification of student-generated representations to learn science is less common. In this paper, we present a framework that aims to integrate three perspectives to explain how and why representational construction supports learning in science. The first or semiotic perspective focuses on student use of particular features of symbolic and material tools to make meanings in science. The second or epistemic perspective focuses on how this representational construction relates to the broader picture of knowledge-building practices of inquiry in this disciplinary field, and the third or epistemological perspective focuses on how and what students can know through engaging in the challenge of representing causal accounts through these semiotic tools. We argue that each perspective entails productive constraints on students' meaning-making as they construct and interpret their own representations. Our framework seeks to take into account the interplay of diverse cultural and cognitive resources students use in these meaning-making processes. We outline the basis for this framework before illustrating its explanatory value through a sequence of lessons on the topic of evaporation.

  10. Translating between Representations in a Social Context: A Study of Undergraduate Science Students' Representational Fluency

    ERIC Educational Resources Information Center

    Nichols, Kim; Ranasinghe, Muditha; Hanan, Jim

    2013-01-01

    Interacting with and translating across multiple representations is an essential characteristic of expertise and representational fluency. In this study, we explored the effect of interacting with and translating between representations in a computer simulation or in a paper-based assignment on scientific accuracy of undergraduate science…

  11. Facial expression recognition with facial parts based sparse representation classifier

    NASA Astrophysics Data System (ADS)

    Zhi, Ruicong; Ruan, Qiuqi

    2009-10-01

    Facial expressions play important role in human communication. The understanding of facial expression is a basic requirement in the development of next generation human computer interaction systems. Researches show that the intrinsic facial features always hide in low dimensional facial subspaces. This paper presents facial parts based facial expression recognition system with sparse representation classifier. Sparse representation classifier exploits sparse representation to select face features and classify facial expressions. The sparse solution is obtained by solving l1 -norm minimization problem with constraint of linear combination equation. Experimental results show that sparse representation is efficient for facial expression recognition and sparse representation classifier obtain much higher recognition accuracies than other compared methods.

  12. An Overview of Recent Research on Multiple Representations

    NASA Astrophysics Data System (ADS)

    Rosengrant, David; Etkina, Eugenia; Van Heuvelen, Alan

    2007-01-01

    In this paper we focus on some of the recent findings of the physics education research community in the area of multiple representations. The overlying trend with the research is how multiple representations help students learn concepts and skills and assist them in problem solving. Two trends developed from the latter are: how students use multiple representations when solving problems and how different representational formats affect student performance in problem solving. We show how our work relates to these trends and provide the reader with an overall synopsis of the findings related to the advantages and disadvantages of multiple representations for learning physics.

  13. Efficient visual tracking via low-complexity sparse representation

    NASA Astrophysics Data System (ADS)

    Lu, Weizhi; Zhang, Jinglin; Kpalma, Kidiyo; Ronsin, Joseph

    2015-12-01

    Thanks to its good performance on object recognition, sparse representation has recently been widely studied in the area of visual object tracking. Up to now, little attention has been paid to the complexity of sparse representation, while most works are focused on the performance improvement. By reducing the computation load related to sparse representation hundreds of times, this paper proposes by far the most computationally efficient tracking approach based on sparse representation. The proposal simply consists of two stages of sparse representation, one is for object detection and the other for object validation. Experimentally, it achieves better performance than some state-of-the-art methods in both accuracy and speed.

  14. Generative Representations for Computer-Automated Design Systems

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2004-01-01

    With the increasing computational power of Computers, software design systems are progressing from being tools for architects and designers to express their ideas to tools capable of creating designs under human guidance. One of the main limitations for these computer-automated design programs is the representation with which they encode designs. If the representation cannot encode a certain design, then the design program cannot produce it. Similarly, a poor representation makes some types of designs extremely unlikely to be created. Here we define generative representations as those representations which can create and reuse organizational units within a design and argue that reuse is necessary for design systems to scale to more complex and interesting designs. To support our argument we describe GENRE, an evolutionary design program that uses both a generative and a non-generative representation, and compare the results of evolving designs with both types of representations.

  15. A method to convert algebraic boundary representations to CSG representations for three-dimensional solids

    SciTech Connect

    Buchele, S.F.; Ellingson, W.A.

    1997-06-01

    Recent advances in reverse engineering have focused on recovering a boundary representation (b-rep) of an object, often for integration with rapid prototyping. This boundary representation may be a 3-D point cloud, a triangulation of points, or piecewise algebraic or parametric surfaces. This paper presents work in progress to develop an algorithm to extend the current state of the art in reverse engineering of mechanical parts. This algorithm will take algebraic surface representations as input and will produce a constructive solid geometry (CSG) description that uses solid primitives such as rectangular block, pyramid, sphere, cylinder, and cone. The proposed algorithm will automatically generate a CSG solid model of a part given its algebraic b-rep, thus allowing direct input into a CAD system and subsequent CSG model generation.

  16. Dictionary Learning Algorithms for Sparse Representation

    PubMed Central

    Kreutz-Delgado, Kenneth; Murray, Joseph F.; Rao, Bhaskar D.; Engan, Kjersti; Lee, Te-Won; Sejnowski, Terrence J.

    2010-01-01

    Algorithms for data-driven learning of domain-specific overcomplete dictionaries are developed to obtain maximum likelihood and maximum a posteriori dictionary estimates based on the use of Bayesian models with concave/Schur-concave (CSC) negative log priors. Such priors are appropriate for obtaining sparse representations of environmental signals within an appropriately chosen (environmentally matched) dictionary. The elements of the dictionary can be interpreted as concepts, features, or words capable of succinct expression of events encountered in the environment (the source of the measured signals). This is a generalization of vector quantization in that one is interested in a description involving a few dictionary entries (the proverbial “25 words or less”), but not necessarily as succinct as one entry. To learn an environmentally adapted dictionary capable of concise expression of signals generated by the environment, we develop algorithms that iterate between a representative set of sparse representations found by variants of FOCUSS and an update of the dictionary using these sparse representations. Experiments were performed using synthetic data and natural images. For complete dictionaries, we demonstrate that our algorithms have improved performance over other independent component analysis (ICA) methods, measured in terms of signal-to-noise ratios of separated sources. In the overcomplete case, we show that the true underlying dictionary and sparse sources can be accurately recovered. In tests with natural images, learned overcomplete dictionaries are shown to have higher coding efficiency than complete dictionaries; that is, images encoded with an over-complete dictionary have both higher compression (fewer bits per pixel) and higher accuracy (lower mean square error). PMID:12590811

  17. The "hospital superbug": social representations of MRSA.

    PubMed

    Washer, Peter; Joffe, Helene

    2006-10-01

    The so-called 'hospital superbug' methcillin-resistant Staphylococcus aureus (MRSA) became a topic of media and political concern in Britain from the middle of the 1990s. It was increasingly politicised in the period leading up to the British General Election of 2005. This study examines the meanings of MRSA that circulate in Britain by analysing newspaper coverage of the disease over the 10-year period 1995-2005. It utilises social representations theory and contextualises MRSA within existing research on representations of emerging infectious diseases (EIDs). A key pattern in the representation of EIDs is to externalise the threat they pose by linking the origin, risk and blame to 'the other' of those who represent them. It is in this light that this study investigates who and what MRSA is associated with and the impact that these associations have on levels of alarm and blame. Key findings are that MRSA is represented as a potentially lethal 'superbug', marking the end of a 'golden age of medicine' in which the story of the discovery of antibiotics has played such a key role. Furthermore, MRSA is constructed around an "it could be you/me" set of assumptions by way of the plethora of human interest stories that dominate the coverage. Finally, the blame for MRSA focuses not on its genesis, but rather on why it spreads. This is attributed to poor hygiene in hospitals, which is ultimately caused by mismanagement of the National Health Service and erosion of the authority and morality symbolised by the 'matron' role. This constellation of meanings informs a somewhat different pattern of response to MRSA when compared to many past EIDs. PMID:16782254

  18. Coordinating different representations in the hippocampus.

    PubMed

    Kelemen, Eduard; Fenton, André A

    2016-03-01

    The processes that organize different thoughts and memories, allowing the separation of currently relevant and irrelevant information, are collectively known as cognitive control. The neuronal mechanisms of these processes can be investigated by place cell ensemble recordings during behaviors and environmental manipulations that present cognitive control challenges to selectively represent one of multiple possible alternative estimates of location. We review place cell studies that investigate responses to manipulations that dissociate the environment into two or more spatial frames of locations, often times to test notions of pattern separation. Manipulations, such as continuously rotating the recording chamber reveal that the ensemble discharge in hippocampus self-organizes into multiple, transiently-organized representations of space, each defined by the subset of coactive cells. Ensemble discharge in the hippocampus alternates between separate representations of frame-specific positions on timescales from 25ms to several seconds. The dynamic, functional grouping of discharge into transiently co-active subsets of cells is predicted by the animal's changing behavioral needs. In addition to identifying neural correlates of cognitive control in hippocampus, these observations demonstrate that the separation of neuronal activity into distinctive representations depends on ongoing cognitive demands and that what can appear as noise, deviations from receptive field tuning, can substantially be the result of these internal knowledge-guided fluctuations. These findings inspire a new perspective that should be taken into account when investigating pattern separation - a perspective that emphasizes changes in hippocampal neural discharge that are happening on a short timescale and does not assume that patterns of neural discharge are steady and stationary across the several minutes of the recordings. PMID:26748023

  19. Neural representation of probabilities for Bayesian inference.

    PubMed

    Rich, Dylan; Cazettes, Fanny; Wang, Yunyan; Peña, José Luis; Fischer, Brian J

    2015-04-01

    Bayesian models are often successful in describing perception and behavior, but the neural representation of probabilities remains in question. There are several distinct proposals for the neural representation of probabilities, but they have not been directly compared in an example system. Here we consider three models: a non-uniform population code where the stimulus-driven activity and distribution of preferred stimuli in the population represent a likelihood function and a prior, respectively; the sampling hypothesis which proposes that the stimulus-driven activity over time represents a posterior probability and that the spontaneous activity represents a prior; and the class of models which propose that a population of neurons represents a posterior probability in a distributed code. It has been shown that the non-uniform population code model matches the representation of auditory space generated in the owl's external nucleus of the inferior colliculus (ICx). However, the alternative models have not been tested, nor have the three models been directly compared in any system. Here we tested the three models in the owl's ICx. We found that spontaneous firing rate and the average stimulus-driven response of these neurons were not consistent with predictions of the sampling hypothesis. We also found that neural activity in ICx under varying levels of sensory noise did not reflect a posterior probability. On the other hand, the responses of ICx neurons were consistent with the non-uniform population code model. We further show that Bayesian inference can be implemented in the non-uniform population code model using one spike per neuron when the population is large and is thus able to support the rapid inference that is necessary for sound localization. PMID:25561333

  20. A link representation for gravity amplitudes

    NASA Astrophysics Data System (ADS)

    He, Song

    2013-10-01

    We derive a link representation for all tree amplitudes in supergravity, from a recent conjecture by Cachazo and Skinner. The new formula explicitly writes amplitudes as contour integrals over constrained link variables, with an integrand naturally expressed in terms of determinants, or equivalently tree diagrams. Important symmetries of the amplitude, such as supersymmetry, parity and (partial) permutation invariance, are kept manifest in the formulation. We also comment on rewriting the formula in a GL( k)-invariant manner, which may serve as a starting point for the generalization to possible Grassmannian contour integrals.

  1. Representations and particles of orthosymplectic supersymmetry generalization

    NASA Astrophysics Data System (ADS)

    Salom, Igor

    2014-12-01

    Orthosymplectic osp(1|2 n) supersymmetry (alternative names: Generalized conformal supersymmetry with tensorial central charges, conformal M-algebra, parabose algebra) has been considered as an alternative to d-dimensional conformal superalgebra. Due to mathematical difficulties, even classification of its unitary irreducible representations (UIR's) have not been entirely accomplished. We give this classification for n = 4 case (corresponding to four dimensional space-time) and then show how the discrete subset of these UIR's can be constructed in a Clifford algebra variation of the Green's ansatz.

  2. Steering in spin tomographic probability representation

    NASA Astrophysics Data System (ADS)

    Man'ko, V. I.; Markovich, L. A.

    2016-09-01

    The steering property known for two-qubit state in terms of specific inequalities for the correlation function is translated for the state of qudit with the spin j = 3 / 2. Since most steering detection inequalities are based on the correlation functions we introduce analogs of such functions for the single qudit systems. The tomographic probability representation for the qudit states is applied. The connection between the correlation function in the two-qubit system and the single qudit is presented in an integral form with an intertwining kernel calculated explicitly in tomographic probability terms.

  3. Shear representations of beam transfer matrices.

    PubMed

    Başkal, S; Kim, Y S

    2001-05-01

    The beam transfer matrix, often called the ABCD matrix, is one of the essential mathematical instruments in optics. It is a unimodular matrix whose determinant is 1. If all the elements are real with three independent parameters, this matrix is a 2 x 2 representation of the group Sp(2). It is shown that a real ABCD matrix can be generated by two shear transformations. It is then noted that, in para-axial lens optics, the lens and translation matrices constitute two shear transformations. It is shown that a system with an arbitrary number of lenses can be reduced to a system consisting of three lenses. PMID:11415030

  4. Knowledge representation into Ada parallel processing

    NASA Technical Reports Server (NTRS)

    Masotto, Tom; Babikyan, Carol; Harper, Richard

    1990-01-01

    The Knowledge Representation into Ada Parallel Processing project is a joint NASA and Air Force funded project to demonstrate the execution of intelligent systems in Ada on the Charles Stark Draper Laboratory fault-tolerant parallel processor (FTPP). Two applications were demonstrated - a portion of the adaptive tactical navigator and a real time controller. Both systems are implemented as Activation Framework Objects on the Activation Framework intelligent scheduling mechanism developed by Worcester Polytechnic Institute. The implementations, results of performance analyses showing speedup due to parallelism and initial efficiency improvements are detailed and further areas for performance improvements are suggested.

  5. Fock representations of exchange algebras with involution

    SciTech Connect

    Liguori, A.; Mintchev, M.; Rossi, M.

    1997-06-01

    An associative algebra scr(A){sub R} with exchange properties generalizing the canonical (anti)commutation relations is considered. We introduce a family of involutions in scr(A){sub R} and construct the relative Fock representations, examining the positivity of the metric. As an application of the general results, we rigorously prove unitarity of the scattering operator of integrable models in 1+1 space-time dimensions. In this context the possibility of adopting various involutions in the Zamolodchikov{endash}Faddeev algebra is also explored. {copyright} {ital 1997 American Institute of Physics.}

  6. Representation and disconnection in imaginal neglect.

    PubMed

    Rode, G; Cotton, F; Revol, P; Jacquin-Courtois, S; Rossetti, Y; Bartolomeo, P

    2010-08-01

    Patients with neglect failure to detect, orient, or respond to stimuli from a spatially confined region, usually on their left side. Often, the presence of perceptual input increases left omissions, while sensory deprivation decreases them, possibly by removing attention-catching right-sided stimuli (Bartolomeo, 2007). However, such an influence of visual deprivation on representational neglect was not observed in patients while they were imagining a map of France (Rode et al., 2007). Therefore, these patients with imaginal neglect either failed to generate the left side of mental images (Bisiach & Luzzatti, 1978), or suffered from a co-occurrence of deficits in automatic (bottom-up) and voluntary (top-down) orienting of attention. However, in Rode et al.'s experiment visual input was not directly relevant to the task; moreover, distraction from visual input might primarily manifest itself when representation guides somatomotor actions, beyond those involved in the generation and mental exploration of an internal map (Thomas, 1999). To explore these possibilities, we asked a patient with right hemisphere damage, R.D., to explore visual and imagined versions of a map of France in three conditions: (1) 'imagine the map in your mind' (imaginal); (2) 'describe a real map' (visual); and (3) 'list the names of French towns' (propositional). For the imaginal and visual conditions, verbal and manual pointing responses were collected; the task was also given before and after mental rotation of the map by 180 degrees . R.D. mentioned more towns on the right side of the map in the imaginal and visual conditions, but showed no representational deficit in the propositional condition. The rightward inner exploration bias in the imaginal and visual conditions was similar in magnitude and was not influenced by mental rotation or response type (verbal responses or manual pointing to locations on a map), thus suggesting that the representational deficit was robust and independent of

  7. Thermal operator representation for Matsubara sums

    SciTech Connect

    Espinosa, Olivier

    2005-03-15

    We prove in full generality the thermal operator representation for Matsubara sums in a relativistic field theory of scalar and fermionic particles. It states that the full result of performing the Matsubara sum associated to any given Feynman graph, in the imaginary-time formalism of finite-temperature field theory, can be directly obtained from its corresponding zero-temperature energy integral, by means of a simple linear operator, which is independent of the external Euclidean energies and whose form depends solely on the topology of the graph.

  8. An ellipsoidal representation of human hand anthropometry

    NASA Technical Reports Server (NTRS)

    Buchholz, Bryan; Armstrong, Thomas J.

    1991-01-01

    Anthropometric data concerning the heometry of the hand's surface are presently modeled as a function of gross external hand measurements; an effort is made to evaluate the accuracy with which ellipsoids describe the geometry of the hand segments. Graphical comparisons indicate that differences between the ellipsoidal approximations and the breadth and depth measurements were greatest near the joints. On the bases of the present data, a set of overlapping ellipsoids could furnish a more accurate representation of hand geometry for adaptation to ellipsoid segment-geometry employing biomechanical models.

  9. A Representation for Fermionic Correlation Functions

    NASA Astrophysics Data System (ADS)

    Feldman, Joel; Knörrer, Horst; Trubowitz, Eugene

    Let dμS(a) be a Gaussian measure on the finitely generated Grassmann algebra A. Given an even W(a)∈A, we construct an operator R on A such that for all f(a)∈A. This representation of the Schwinger functional iteratively builds up Feynman graphs by successively appending lines farther and farther from f. It allows the Pauli exclusion principle to be implemented quantitatively by a simple application of Gram's inequality.

  10. Influence of TFT-LCD pixel structure on holographic representation

    NASA Astrophysics Data System (ADS)

    Wang, Hongjun; Wang, Zhao; Tian, Ailing; Liu, Bingcai

    2008-09-01

    As a new holographic display device, TFT-LCD (Thin Film Transistor Liquid Crystal Displays) is key technical component of holographic representation for easy controlled by computer. With the development of exquisite processing technology, that it instead of the traditional holographic plate become historical necessity and would be the development direction of holographic optics. Based on principles of holography and display character of LCD, the property which the LCD was used as a holographic plate was analyzed. The emphasis on discuss influence of LCD black matrix on holographic representation. First, analyzed on LCD pixel structure, the LCD pixel structure mathematical model was established. LCD was character representation by pixel structure parameters. Then, the influence of LCD pixels structure on holographic representation was analyzed by computer simulation. Meanwhile, the SONY LCX023 was chosen for holographic plate, the He-Ne laser which the wavelength is 0.6328um was holographic representation light source. The holographic representation system was established for test influence of LCD on holographic representation. Final, compared between computer simulations and optical experimental results, the mathematical model of LCD was proved to be true. When aperture ratio is 0.625, the holographic representation wouldn't be distinguished between representation images. At the same time, some useful results was acquired for improve application effects of LCD in holographic representation.

  11. Spin Circuit Representation for Spin Pumping Phenomena

    NASA Astrophysics Data System (ADS)

    Roy, Kuntal; Datta, Supriyo

    2015-03-01

    There has been enormous progress in the field of spintronics and nanomagnetics in recent years with the discovery of many new materials and phenomena and it remains a formidable challenge to integrate these phenomena into functional devices and evaluate their potential. To facilitate this process a modular approach has been proposed whereby different phenomena are represented by spin circuit components. Unlike ordinary circuit components, these spin circuit components are characterized by 4-component voltages and currents (one for charge and three for spin). In this talk we will (1) present a spin circuit representation for spin pumping phenomena, (2) combine it with a spin circuit representation for the spin Hall effect to show that it reproduces established results obtained earlier by other means, and finally (3) use it to propose a possible method for enhancing the spin pumping efficiency by an order of magnitude through the addition of a spin sink layer. This work was supported by FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA.

  12. A numerical study of thin flame representations

    SciTech Connect

    Rotman, D.A.; Pindera, M.Z.

    1989-08-11

    In studies of reacting flows, the flame may be viewed as a moving discontinuity endowed with certain properties; notably, it acts as a source of velocity and vorticity. Asymptotic analysis shows this to be justified provided that the flame curvature is small compared to the flame thickness. Such an approach is useful when one is interested in the hydrodynamic effects of the flame on the surrounding flowfield. In numerical models of this kind it is customary to treat the discontinuity as a collection of discrete velocity blobs. In this study, we show that the velocities associated with such a representation can be very non-smooth, particularly very near to the flame surface. As an alternative, we propose the use of a finite line source as the basic flame element. Comparisons of the two flame representations are made for several simple test cases as well as for a flame propagating through an enclosure forming the tulip shape. The results show that the use of line sources eliminates spurious fluctuations in nearfield velocities thus allowing for a more accurate calculation of flame propagation and flame-flowfield interactions. 7 refs., 15 figs.

  13. Competition and Cooperation among Relational Memory Representations.

    PubMed

    Schwarb, Hillary; Watson, Patrick D; Campbell, Kelsey; Shander, Christopher L; Monti, Jim M; Cooke, Gillian E; Wang, Jane X; Kramer, Arthur F; Cohen, Neal J

    2015-01-01

    Mnemonic processing engages multiple systems that cooperate and compete to support task performance. Exploring these systems' interaction requires memory tasks that produce rich data with multiple patterns of performance sensitive to different processing sub-components. Here we present a novel context-dependent relational memory paradigm designed to engage multiple learning and memory systems. In this task, participants learned unique face-room associations in two distinct contexts (i.e., different colored buildings). Faces occupied rooms as determined by an implicit gender-by-side rule structure (e.g., male faces on the left and female faces on the right) and all faces were seen in both contexts. In two experiments, we use behavioral and eye-tracking measures to investigate interactions among different memory representations in both younger and older adult populations; furthermore we link these representations to volumetric variations in hippocampus and ventromedial PFC among older adults. Overall, performance was very accurate. Successful face placement into a studied room systematically varied with hippocampal volume. Selecting the studied room in the wrong context was the most typical error. The proportion of these errors to correct responses positively correlated with ventromedial prefrontal volume. This novel task provides a powerful tool for investigating both the unique and interacting contributions of these systems in support of relational memory. PMID:26619203

  14. Competition and Cooperation among Relational Memory Representations

    PubMed Central

    Schwarb, Hillary; Watson, Patrick D.; Campbell, Kelsey; Shander, Christopher L.; Monti, Jim M.; Cooke, Gillian E.; Wang, Jane X.; Kramer, Arthur F.; Cohen, Neal J.

    2015-01-01

    Mnemonic processing engages multiple systems that cooperate and compete to support task performance. Exploring these systems’ interaction requires memory tasks that produce rich data with multiple patterns of performance sensitive to different processing sub-components. Here we present a novel context-dependent relational memory paradigm designed to engage multiple learning and memory systems. In this task, participants learned unique face-room associations in two distinct contexts (i.e., different colored buildings). Faces occupied rooms as determined by an implicit gender-by-side rule structure (e.g., male faces on the left and female faces on the right) and all faces were seen in both contexts. In two experiments, we use behavioral and eye-tracking measures to investigate interactions among different memory representations in both younger and older adult populations; furthermore we link these representations to volumetric variations in hippocampus and ventromedial PFC among older adults. Overall, performance was very accurate. Successful face placement into a studied room systematically varied with hippocampal volume. Selecting the studied room in the wrong context was the most typical error. The proportion of these errors to correct responses positively correlated with ventromedial prefrontal volume. This novel task provides a powerful tool for investigating both the unique and interacting contributions of these systems in support of relational memory. PMID:26619203

  15. Language dependent vowel representation in speech production

    PubMed Central

    Mitsuya, Takashi; Samson, Fabienne; Ménard, Lucie; Munhall, Kevin G.

    2013-01-01

    The representation of speech goals was explored using an auditory feedback paradigm. When talkers produce vowels the formant structure of which is perturbed in real time, they compensate to preserve the intended goal. When vowel formants are shifted up or down in frequency, participants change the formant frequencies in the opposite direction to the feedback perturbation. In this experiment, the specificity of vowel representation was explored by examining the magnitude of vowel compensation when the second formant frequency of a vowel was perturbed for speakers of two different languages (English and French). Even though the target vowel was the same for both language groups, the pattern of compensation differed. French speakers compensated to smaller perturbations and made larger compensations overall. Moreover, French speakers modified the third formant in their vowels to strengthen the compensation even though the third formant was not perturbed. English speakers did not alter their third formant. Changes in the perceptual goodness ratings by the two groups of participants were consistent with the threshold to initiate vowel compensation in production. These results suggest that vowel goals not only specify the quality of the vowel but also the relationship of the vowel to the vowel space of the spoken language. PMID:23654403

  16. Representations of Super Yang-Mills Algebras

    NASA Astrophysics Data System (ADS)

    Herscovich, Estanislao

    2013-06-01

    We study in this article the representation theory of a family of super algebras, called the super Yang-Mills algebras, by exploiting the Kirillov orbit method à la Dixmier for nilpotent super Lie algebras. These super algebras are an extension of the so-called Yang-Mills algebras, introduced by A. Connes and M. Dubois-Violette in (Lett Math Phys 61(2):149-158, 2002), and in fact they appear as a "background independent" formulation of supersymmetric gauge theory considered in physics, in a similar way as Yang-Mills algebras do the same for the usual gauge theory. Our main result states that, under certain hypotheses, all Clifford-Weyl super algebras {{Cliff}q(k) ⊗ Ap(k)}, for p ≥ 3, or p = 2 and q ≥ 2, appear as a quotient of all super Yang-Mills algebras, for n ≥ 3 and s ≥ 1. This provides thus a family of representations of the super Yang-Mills algebras.

  17. Optimizing protein representations with information theory.

    PubMed

    Mintseris, Julian; Weng, Zhiping

    2004-01-01

    The problem of describing a protein representation by breaking up the amino acids atoms into functionally similar atom groups has been addressed by many researchers in the past 25 years. They have used a variety of physical, chemical and biological criteria of varying degrees of rigor to essentially impose our understanding of protein structures onto various atom-typing schemes used in studies of protein folding, protein-protein and protein-ligand interactions, and others. Here, instead, we have chosen to rely primarily on the data and use information-theoretic techniques to dissect it. We show that we can obtain an optimized protein representation for a given alphabet size from protein monomers or protein interface datasets that are in agreement with general concepts of protein energetics. Closer inspection of the atom partitions led to interesting observations pointing to the greater importance of the hydrophobic interactions in protein monomers compared to interfaces and, conversely, greater importance of polar/charged interaction in protein interfaces. Comparing the atom partitions from the two datasets we show that the two are strikingly similar at alphabet size of five, proving that despite some differences, the general energetic concepts are very similar for folding and binding. Implications for further structural studies are discussed. PMID:15712119

  18. Geometric representation of fundamental particles' inertial mass

    SciTech Connect

    Schachter, L.; Spencer, James

    2015-07-22

    A geometric representation of the (N = 279) masses of quarks, leptons, hadrons and gauge bosons was introduced by employing a Riemann Sphere facilitating the interpretation of the N masses in terms of a single particle, the Masson, which might be in one of the N eigen-states. Geometrically, its mass is the radius of the Riemann Sphere. Dynamically, its derived mass is near the mass of the nucleon regardless of whether it is determined from all N particles of only the hadrons, the mesons or the baryons separately. Ignoring all the other properties of these particles, it is shown that the eigen-values, the polar representation θν of the masses on the Sphere, satisfy the symmetry θν + θN+1-ν = π within less than 1% relative error. In addition, these pair correlations include the pairs θγ + θtop ≃ π and θgluon + θH ≃ π as well as pairing the weak gauge bosons with the three neutrinos.

  19. Attention Stabilizes Representations in the Human Hippocampus.

    PubMed

    Aly, Mariam; Turk-Browne, Nicholas B

    2016-02-01

    Attention and memory are intricately linked, but how attention modulates brain areas that subserve memory, such as the hippocampus, is unknown. We hypothesized that attention may stabilize patterns of activity in human hippocampus, resulting in distinct but reliable activity patterns for different attentional states. To test this prediction, we utilized high-resolution functional magnetic resonance imaging and a novel "art gallery" task. On each trial, participants viewed a room containing a painting, and searched a stream of rooms for a painting from the same artist (art state) or a room with the same layout (room state). Bottom-up stimulation was the same in both tasks, enabling the isolation of neural effects related to top-down attention. Multivariate analyses revealed greater pattern similarity in all hippocampal subfields for trials from the same, compared with different, attentional state. This stability was greater for the room than art state, was unrelated to univariate activity, and, in CA2/CA3/DG, was correlated with behavior. Attention therefore induces representational stability in the human hippocampus, resulting in distinct activity patterns for different attentional states. Modulation of hippocampal representational stability highlights the far-reaching influence of attention outside of sensory systems. PMID:25766839

  20. Representation of chromatic distribution for lighting system

    NASA Astrophysics Data System (ADS)

    Rossi, Maurizio; Musante, Fulvio

    2015-01-01

    For the luminaire manufacturer, the measurement of the lighting intensity distribution (LID) emitted by lighting fixture is based on photometry. So light is measured as an achromatic value of intensity and there is no the possibility to discriminate the measurement of white vs. colored light. At the Laboratorio Luce of Politecnico di Milano a new instrument for the measurement of spectral radiant intensities distribution for lighting system has been built: the goniospectra- radiometer. This new measuring tool is based on a traditional mirror gonio-photometer with a CCD spectraradiometer controlled by a PC. Beside the traditional representation of photometric distribution we have introduced a new representation where, in addition to the information about the distribution of luminous intensity in space, new details about the chromaticity characteristic of the light sources have been implemented. Some of the results of this research have been applied in developing and testing a new line of lighting system "My White Light" (the research project "Light, Environment and Humans" funded in the Italian Lombardy region Metadistretti Design Research Program involving Politecnico di Milano, Artemide, Danese, and some other SME of the Lighting Design district), giving scientific notions and applicative in order to support the assumption that colored light sources can be used for the realization of interior luminaries that, other than just have low power consumption and long life, may positively affect the mood of people.

  1. Lyapunov Exponents for Surface Group Representations

    NASA Astrophysics Data System (ADS)

    Deroin, Bertrand; Dujardin, Romain

    2015-12-01

    Let be a holomorphic family of representations of a surface group into , where S is a topological (possibly punctured) surface with negative Euler characteristic. Given a structure of Riemann surface of finite type on S we construct a bifurcation current on the parameter space Λ, that is a (1,1) positive closed current attached to the bifurcations of the family. It is defined as the dd c of the Lyapunov exponent of the representation with respect to the Brownian motion on the Riemann surface S, endowed with its Poincaré metric. We show that this bifurcation current describes the asymptotic distribution of various codimension 1 phenomena in Λ. For instance, the random hypersurfaces of Λ defined by the condition that a random closed geodesic on S is mapped under ρ λ to a parabolic element or the identity are asymptotically equidistributed with respect to the bifurcation current. The proofs are based on our previous work (Deroin and Dujardin, Invent Math 190:57-118, 2012), and on a careful control of a discretization procedure of the Brownian motion.

  2. Neuronal foundations of human numerical representations.

    PubMed

    Eger, E

    2016-01-01

    The human species has developed complex mathematical skills which likely emerge from a combination of multiple foundational abilities. One of them seems to be a preverbal capacity to extract and manipulate the numerosity of sets of objects which is shared with other species and in humans is thought to be integrated with symbolic knowledge to result in a more abstract representation of numerical concepts. For what concerns the functional neuroanatomy of this capacity, neuropsychology and functional imaging have localized key substrates of numerical processing in parietal and frontal cortex. However, traditional fMRI mapping relying on a simple subtraction approach to compare numerical and nonnumerical conditions is limited to tackle with sufficient precision and detail the issue of the underlying code for number, a question which more easily lends itself to investigation by methods with higher spatial resolution, such as neurophysiology. In recent years, progress has been made through the introduction of approaches sensitive to within-category discrimination in combination with fMRI (adaptation and multivariate pattern recognition), and the present review summarizes what these have revealed so far about the neural coding of individual numbers in the human brain, the format of these representations and parallels between human and monkey neurophysiology findings. PMID:27339006

  3. Processing geometric representations on SIMD computers

    SciTech Connect

    Hung, Y.

    1988-01-01

    This thesis contributes to designing parallel algorithms to process border and linear quadtree representations on mesh-connected computers (MCCs) and hypercubes. This thesis consists of two parts. The first part studies some primitive operations on mesh-connected computers and hypercubes. These include various routing tasks and several versions of the parallel prefix algorithms. It is shown how general routings can be done in O(n) time on an n {times} n mesh and O(d{sup 2}) on a d-dimensional hypercube (d-cube). Also presented are optimal routing algorithms for some classes of permutation routings. For the parallel prefix problem, the author describes how the initial prefixes can be computed efficiently when the data are mapped into the MCC or the hypercube in some specific manners. The second part deals with processing border codes and linear quadtrees. These include generating border codes and linear quadtrees from a given image, reconstructing the image from its geometric representations, computing various geometric properties, answering the point-in-region query, performing set operations, etc. For linear quadtrees, algorithms are also designed for finding neighbors of equal or larger size for all nodes simultaneously. A connected component-labeling algorithm is also presented.

  4. Computing with scale-invariant neural representations

    NASA Astrophysics Data System (ADS)

    Howard, Marc; Shankar, Karthik

    The Weber-Fechner law is perhaps the oldest quantitative relationship in psychology. Consider the problem of the brain representing a function f (x) . Different neurons have receptive fields that support different parts of the range, such that the ith neuron has a receptive field at xi. Weber-Fechner scaling refers to the finding that the width of the receptive field scales with xi as does the difference between the centers of adjacent receptive fields. Weber-Fechner scaling is exponentially resource-conserving. Neurophysiological evidence suggests that neural representations obey Weber-Fechner scaling in the visual system and perhaps other systems as well. We describe an optimality constraint that is solved by Weber-Fechner scaling, providing an information-theoretic rationale for this principle of neural coding. Weber-Fechner scaling can be generated within a mathematical framework using the Laplace transform. Within this framework, simple computations such as translation, correlation and cross-correlation can be accomplished. This framework can in principle be extended to provide a general computational language for brain-inspired cognitive computation on scale-invariant representations. Supported by NSF PHY 1444389 and the BU Initiative for the Physics and Mathematics of Neural Systems,.

  5. Geohazards storytelling between reality and representation

    NASA Astrophysics Data System (ADS)

    Musacchio, Gemma; Candela, Andrea; Canel, Samanta; Roi, Cinzia

    2015-04-01

    Ethics towards geohazards might start at early age and it might radicate on narratives occuring in the media, as disfuctional ideas and perception are passed from school or society to children. In this paper we study the representations and imaginaries of natural hazards as they are in the media and how they are passed on chidren and laypeople. The investigation is led on an experimental basis on primary schools in Northern Italy (Varese province), where data concerning school education are collected. The approach is that of the storytelling that allow evaluation of children perception of hazard and risk. Narratives (news, rhetorics, images and pictures, symbols, metaphores and interpretations) that mass media and education generally used in order to explain and represent geohazards (earthquakes, volcanoes, hydrogeological instability, climate change and so on) are also analysed. They are responsible for certain individual and collective perceptions, indeed. The research has attempted to analyze how imaginaries and common "wrong" ideas can influence environmental education and public communication of natural hazards. A better understanding of feelings (fears and hopes), and all cultural behaviours included in the social construction of collective narratives and representations of environmental emergencies could be useful in order to re-orient education and communication strategies on the basis of more targeted and participatory approaches.

  6. Representational Constraints on the Development of Memory and Metamemory: A Developmental-Representational Theory

    ERIC Educational Resources Information Center

    Ceci, Stephen J.; Fitneva, Stanka A.; Williams, Wendy M.

    2010-01-01

    Traditional accounts of memory development suggest that maturation of prefrontal cortex (PFC) enables efficient metamemory, which enhances memory. An alternative theory is described, in which changes in early memory and metamemory are mediated by representational changes, independent of PFC maturation. In a pilot study and Experiment 1, younger…

  7. The body schema and the multisensory representation(s) of peripersonal space

    PubMed Central

    Holmes, Nicholas P.; Spence, Charles

    2005-01-01

    In order to guide the movement of the body through space, the brain must constantly monitor the position and movement of the body in relation to nearby objects. The effective ‘piloting’ of the body to avoid or manipulate objects in pursuit of behavioural goals (Popper & Eccles, 1977, p. 129), requires an integrated neural representation of the body (the ‘body schema’) and of the space around the body (‘peripersonal space’). In the review that follows, we describe and evaluate recent results from neurophysiology, neuropsychology, and psychophysics in both human and non-human primates that support the existence of an integrated representation of visual, somatosensory, and auditory peripersonal space. Such a representation involves primarily visual, somatosensory, and proprioceptive modalities, operates in body part-centred reference frames, and demonstrates significant plasticity. Recent research shows that the use of tools, the viewing of one’s body or body parts in mirrors, and in video-monitors, may also modulate the visuotactile representation of peripersonal space. PMID:16467906

  8. Representational Classroom Practices that Contribute to Students' Conceptual and Representational Understanding of Chemical Bonding

    ERIC Educational Resources Information Center

    Hilton, Annette; Nichols, Kim

    2011-01-01

    Understanding bonding is fundamental to success in chemistry. A number of alternative conceptions related to chemical bonding have been reported in the literature. Research suggests that many alternative conceptions held by chemistry students result from previous teaching; if teachers are explicit in the use of representations and explain their…

  9. Partners' representations of diabetes as mediators between patients' representations and adherence to self-care behaviors, in type 2 diabetes.

    PubMed

    Pereira, M Graça; Pedras, Susana; Machado, José C; Ferreira, Gabriela

    2016-09-01

    The purpose of this study was to analyze partners' representations of diabetes as mediators between patients' illness representations and adherence to all self-care behaviors, in recently diagnosed type 2 diabetes (T2DM) patients. The sample included 340 patients and their respective partners. The instruments used were: Revised Summary of Diabetes Self-Care Activities (RSDSCA); Medication Adherence Report Scale (MARS); and the Brief Illness Perception Questionnaire  (Brief-IPQ). A mediational effect of partners' representation of diabetes consequences was found between the same patients' representations and  exercise, foot care, and self-monitoring of blood glucose. Partners' representations of personal and treatment control, were mediators between the same partners' representations and self-monitoring of blood glucose. No partners' representations mediated patients' representation and adherence to medication or diet . This study emphasized partners' representations on patient's adherence to exercise, foot care and monitoring of blood glucose, in recent diagnosed T2DM patients. Interventions to promote adherence in T2DM should promote convergence between patients and partners' diabetes representations. This study provides some evidence for the need to treat T2DM within the dyad to improve adherence, starting after the diagnosis. PMID:26718034

  10. Reevaluating the two-representation model of numerical magnitude processing.

    PubMed

    Jiang, Ting; Zhang, Wenfeng; Wen, Wen; Zhu, Haiting; Du, Han; Zhu, Xiangru; Gao, Xuefei; Zhang, Hongchuan; Dong, Qi; Chen, Chuansheng

    2016-01-01

    One debate in mathematical cognition centers on the single-representation model versus the two-representation model. Using an improved number Stroop paradigm (i.e., systematically manipulating physical size distance), in the present study we tested the predictions of the two models for number magnitude processing. The results supported the single-representation model and, more importantly, explained how a design problem (failure to manipulate physical size distance) and an analytical problem (failure to consider the interaction between congruity and task-irrelevant numerical distance) might have contributed to the evidence used to support the two-representation model. This study, therefore, can help settle the debate between the single-representation and two-representation models. PMID:26268066

  11. Cognitive Dissonance as an Instructional Tool for Understanding Chemical Representations

    NASA Astrophysics Data System (ADS)

    Corradi, David; Clarebout, Geraldine; Elen, Jan

    2015-10-01

    Previous research on multiple external representations (MER) indicates that sequencing representations (compared with presenting them as a whole) can, in some cases, increase conceptual understanding if there is interference between internal and external representations. We tested this mechanism by sequencing different combinations of scientific and abstract chemical representations and presenting them to 133 learners with low prior knowledge of the represented domain. The results provide insight into three separate mechanisms of learning with MER. (1) A memory (number of ideas reproduced) and (2) an accuracy (correctness of these ideas) effects occur when two representations are presented in a sequence. An accuracy and a (3) redundancy (number of redundant ideas remembered) effects occur when three representations are presented in a sequence. A necessary precondition for these effects is that descriptive formats are placed before depictive formats. The identified effects are analyzed in terms of the concept of cognitive dissonance.

  12. The heterogeneity of mental representation: Ending the imagery debate

    PubMed Central

    Pearson, Joel; Kosslyn, Stephen M.

    2015-01-01

    The possible ways that information can be represented mentally have been discussed often over the past thousand years. However, this issue could not be addressed rigorously until late in the 20th century. Initial empirical findings spurred a debate about the heterogeneity of mental representation: Is all information stored in propositional, language-like, symbolic internal representations, or can humans use at least two different types of representations (and possibly many more)? Here, in historical context, we describe recent evidence that humans do not always rely on propositional internal representations but, instead, can also rely on at least one other format: depictive representation. We propose that the debate should now move on to characterizing all of the different forms of human mental representation. PMID:26175024

  13. When Does Changing Representation Improve Problem-Solving Performance?

    NASA Technical Reports Server (NTRS)

    Holte, Robert; Zimmer, Robert; MacDonald, Alan

    1992-01-01

    The aim of changing representation is the improvement of problem-solving efficiency. For the most widely studied family of methods of change of representation it is shown that the value of a single parameter, called the expulsion factor, is critical in determining (1) whether the change of representation will improve or degrade problem-solving efficiency and (2) whether the solutions produced using the change of representation will or will not be exponentially longer than the shortest solution. A method of computing the expansion factor for a given change of representation is sketched in general and described in detail for homomorphic changes of representation. The results are illustrated with homomorphic decompositions of the Towers of Hanoi problem.

  14. The heterogeneity of mental representation: Ending the imagery debate.

    PubMed

    Pearson, Joel; Kosslyn, Stephen M

    2015-08-18

    The possible ways that information can be represented mentally have been discussed often over the past thousand years. However, this issue could not be addressed rigorously until late in the 20th century. Initial empirical findings spurred a debate about the heterogeneity of mental representation: Is all information stored in propositional, language-like, symbolic internal representations, or can humans use at least two different types of representations (and possibly many more)? Here, in historical context, we describe recent evidence that humans do not always rely on propositional internal representations but, instead, can also rely on at least one other format: depictive representation. We propose that the debate should now move on to characterizing all of the different forms of human mental representation. PMID:26175024

  15. Temporal Stability and Authenticity of Self-Representations in Adulthood

    PubMed Central

    Diehl, Manfred; Jacobs, Laurie M.; Hastings, Catherine T.

    2008-01-01

    The temporal stability of role-specific self-representations was examined in a sample of 188 young, middle-aged, and older adults. Considerable stability was observed for all self-representations. Central self-descriptors showed significantly greater temporal stability than peripheral self-descriptors. Temporal stability of self-representations was positively associated with self-concept clarity, self-esteem, and positive affect (PA). Age differences were obtained for three of the five self-representations, with older adults showing significantly lower stabilities for self with family, self with friend, and self with significant other compared to young and middle-aged adults. Assessment of the authenticity of adults’ role-specific self-representations showed that greater authenticity tended to be associated with greater temporal stability. Authenticity and the number of positive daily events were significant positive predictors of the stability of self-representations. PMID:18820732

  16. Language, perception, and the schematic representation of spatial relations

    PubMed Central

    Amorapanth, Prin; Kranjec, Alexander; Bromberger, Bianca; Lehet, Matthew; Widick, Page; Woods, Adam J.; Kimberg, Daniel Y.; Chatterjee, Anjan

    2011-01-01

    Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual representations on the other. In patients with either left hemisphere damage or right hemisphere damage, a battery of matching tasks depicting categorical spatial relations was used to probe for the comprehension of basic spatial concepts across distinct representational formats (words, pictures, and schemas). Left hemisphere patients underperformed right hemisphere patients across all tasks. However, focused residual analyses using VLSM (voxel-based lesion-symptom mapping) suggest that (1) left hemisphere deficits in the representation of categorical spatial relations are difficult to distinguish from deficits in naming these relations and (2) the right hemisphere plays a special role in extracting schematic representations from richly textured pictures. PMID:22070948

  17. Language, perception, and the schematic representation of spatial relations.

    PubMed

    Amorapanth, Prin; Kranjec, Alexander; Bromberger, Bianca; Lehet, Matthew; Widick, Page; Woods, Adam J; Kimberg, Daniel Y; Chatterjee, Anjan

    2012-03-01

    Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual representations on the other. In patients with either left hemisphere damage or right hemisphere damage, a battery of matching tasks depicting categorical spatial relations was used to probe for the comprehension of basic spatial concepts across distinct representational formats (words, pictures, and schemas). Left hemisphere patients underperformed right hemisphere patients across all tasks. However, focused residual analyses using voxel-based lesion-symptom mapping (VLSM) suggest that (1) left hemisphere deficits in the representation of categorical spatial relations are difficult to distinguish from deficits in naming these relations and (2) the right hemisphere plays a special role in extracting schematic representations from richly textured pictures. PMID:22070948

  18. Decomposability and mental representation of French verbs

    PubMed Central

    Estivalet, Gustavo L.; Meunier, Fanny E.

    2015-01-01

    In French, regardless of stem regularity, inflectional verbal suffixes are extremely regular and paradigmatic. Considering the complexity of the French verbal system, we argue that all French verbs are polymorphemic forms that are decomposed during visual recognition independently of their stem regularity. We conducted a behavioral experiment in which we manipulated the surface and cumulative frequencies of verbal inflected forms and asked participants to perform a visual lexical decision task. We tested four types of verbs with respect to their stem variants: a. fully regular (parler “to speak,” [parl-]); b. phonological change e/E verbs with orthographic markers (répéter “to repeat,” [répét-] and [répèt-]); c. phonological change o/O verbs without orthographic markers (adorer “to adore,” [ador-] and [adOr-]); and d. idiosyncratic (boire “to drink,” [boi-] and [buv-]). For each type of verb, we contrasted four conditions, forms with high and low surface frequencies and forms with high and low cumulative frequencies. Our results showed a significant cumulative frequency effect for the fully regular and idiosyncratic verbs, indicating that different stems within idiosyncratic verbs (such as [boi-] and [buv-]) have distinct representations in the mental lexicon as different fully regular verbs. For the phonological change verbs, we found a significant cumulative frequency effect only when considering the two forms of the stem together ([répét-] and [répèt-]), suggesting that they share a single abstract and under specified phonological representation. Our results also revealed a significant surface frequency effect for all types of verbs, which may reflect the recombination of the stem lexical representation with the functional information of the suffixes. Overall, these results indicate that all inflected verbal forms in French are decomposed during visual recognition and that this process could be due to the regularities of the French

  19. [Training and representation of dementia of workers in nursing homes].

    PubMed

    Sanchez, Stéphane; Gallin, Aurélie; Stefanuto, Muriel; Treffel, Sylvie; Antoine, Marc; Denormandie, Philippe

    2016-01-01

    Training could be a lever for improving the quality of care of residents with dementia in nursing homes by changing social representations. Beyond a simple assessment of acquired knowledge, a change of social representations could be indicative of a true appropriation of the content of the training. A study was carried out to assess the impact of training on nursing home caregivers' representations of dementia and Alzheimer's disease. PMID:26976314

  20. An integral representation of functions in gas-kinetic models

    NASA Astrophysics Data System (ADS)

    Perepelitsa, Misha

    2016-08-01

    Motivated by the theory of kinetic models in gas dynamics, we obtain an integral representation of lower semicontinuous functions on {{{R}}^d,} {d≥1}. We use the representation to study the problem of compactness of a family of the solutions of the discrete time BGK model for the compressible Euler equations. We determine sufficient conditions for strong compactness of moments of kinetic densities, in terms of the measures from their integral representations.

  1. Character recognition using a neural network model with fuzzy representation

    NASA Technical Reports Server (NTRS)

    Tavakoli, Nassrin; Seniw, David

    1992-01-01

    The degree to which digital images are recognized correctly by computerized algorithms is highly dependent upon the representation and the classification processes. Fuzzy techniques play an important role in both processes. In this paper, the role of fuzzy representation and classification on the recognition of digital characters is investigated. An experimental Neural Network model with application to character recognition was developed. Through a set of experiments, the effect of fuzzy representation on the recognition accuracy of this model is presented.

  2. Gestalt-like representations hijack Chunk-and-Pass processing.

    PubMed

    Dumitru, Magda L

    2016-01-01

    Christiansen & Chater (C&C) make two related and somewhat contradictory claims, namely that the ever abstract language representations built during Chunk-and-Pass processing allow for ever greater interference from extra-linguistic information, and that it is nevertheless the language system that re-codes incoming information into abstract representations. I analyse these claims and discuss evidence suggesting that Gestalt-like representations hijack Chunk-and-Pass processing. PMID:27562687

  3. Trigonometric series representations of the orbital inclination function

    NASA Astrophysics Data System (ADS)

    El-Sayed Awad, M.

    1986-08-01

    New trigonometric representations of the orbital inclination function in multiples of cosines or sines are developed for all possible values of l, m, and p. The literal analytical expressions and the recurrence formulas which are satisfied by their coefficients are derived, and an efficient algorithm for the table formulation of the trigonometric series representations is presented. Numerical examples for the representations are demonstrated for the cases l = 2(1)4, m = 0(1)l, and p = 0(1)l.

  4. Analyse conversationnelle et representations sociales: Unite et diversite de L'image du bilinguisme (Conversational Analysis and Social Representations: Unity and Diversity in the Image of Bilingualism).

    ERIC Educational Resources Information Center

    Py, Bernard, Ed.

    2000-01-01

    Articles in this issue include the following: "Representations sociales et discours. Questions epistemologiques et methodologiques" (Social Representations and Discourse. Questions of Epistemology and Methodology); "Aspects theoretiques et methodologiques de la recherche sur le traitement discursif des representations sociales" (Theoretical and…

  5. 27 CFR 478.128 - False statement or representation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... collector who knowingly makes any false statement or representation with respect to any information required...) Any licensed manufacturer, licensed importer, licensed dealer, or licensed collector who...

  6. 27 CFR 478.128 - False statement or representation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... collector who knowingly makes any false statement or representation with respect to any information required...) Any licensed manufacturer, licensed importer, licensed dealer, or licensed collector who...

  7. 27 CFR 478.128 - False statement or representation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... collector who knowingly makes any false statement or representation with respect to any information required...) Any licensed manufacturer, licensed importer, licensed dealer, or licensed collector who...

  8. Visual representations are dominated by intrinsic fluctuations correlated between areas.

    PubMed

    Henriksson, Linda; Khaligh-Razavi, Seyed-Mahdi; Kay, Kendrick; Kriegeskorte, Nikolaus

    2015-07-01

    Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1-3 and a categorical animate-inanimate model in the object-responsive lateral occipital cortex. PMID:25896934

  9. Workshop on Aircraft Surface Representation for Aerodynamic Computation

    NASA Technical Reports Server (NTRS)

    Gregory, T. J. (Editor); Ashbaugh, J. (Editor)

    1980-01-01

    Papers and discussions on surface representation and its integration with aerodynamics, computers, graphics, wind tunnel model fabrication, and flow field grid generation are presented. Surface definition is emphasized.

  10. Representation use and strategy choice in physics problem solving

    NASA Astrophysics Data System (ADS)

    De Cock, Mieke

    2012-12-01

    In this paper, we examine student success on three variants of a test item given in different representational formats (verbal, pictorial, and graphical), with an isomorphic problem statement. We confirm results from recent papers where it is mentioned that physics students’ problem-solving competence can vary with representational format and that solutions can be triggered by particular details of the representation. Previous studies are complemented with a fine grained analysis of solution strategies. We find that students use different problem-solving strategies, depending on the representational format in which the problem is stated.

  11. Visual representations are dominated by intrinsic fluctuations correlated between areas

    PubMed Central

    Henriksson, Linda; Khaligh-Razavi, Seyed-Mahdi; Kay, Kendrick; Kriegeskorte, Nikolaus

    2015-01-01

    Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1–3 and a categorical animate–inanimate model in the object-responsive lateral occipital cortex. PMID:25896934

  12. Lexical is as lexical does: computational approaches to lexical representation

    PubMed Central

    Woollams, Anna M.

    2015-01-01

    In much of neuroimaging and neuropsychology, regions of the brain have been associated with ‘lexical representation’, with little consideration as to what this cognitive construct actually denotes. Within current computational models of word recognition, there are a number of different approaches to the representation of lexical knowledge. Structural lexical representations, found in original theories of word recognition, have been instantiated in modern localist models. However, such a representational scheme lacks neural plausibility in terms of economy and flexibility. Connectionist models have therefore adopted distributed representations of form and meaning. Semantic representations in connectionist models necessarily encode lexical knowledge. Yet when equipped with recurrent connections, connectionist models can also develop attractors for familiar forms that function as lexical representations. Current behavioural, neuropsychological and neuroimaging evidence shows a clear role for semantic information, but also suggests some modality- and task-specific lexical representations. A variety of connectionist architectures could implement these distributed functional representations, and further experimental and simulation work is required to discriminate between these alternatives. Future conceptualisations of lexical representations will therefore emerge from a synergy between modelling and neuroscience. PMID:25893204

  13. Graphical representation of robot grasping quality measures

    SciTech Connect

    Varma, V.; Tasch, U.

    1993-11-01

    When an object is held by a multi-fingered hand, the values of the contact forces can be multivalued. An objective function, when used in conjunction with the frictional and geometric constraints of the grasp, can however, give a unique set of finger force values. The selection of the objective function in determining the finger forces is dependent on the type of grasp required, the material properties of the object, and the limitations of the robot fingers. In this paper several optimization functions are studied and their merits highlighted. A graphical representation of the finger force values and the objective function is introduced that enable one in selecting and comparing various grasping configurations. The impending motion of the object at different torque and finger force values are determined by observing the normalized coefficient of friction plots.

  14. Morse Potential in the Momentum Representation

    NASA Astrophysics Data System (ADS)

    Sun, Guo-Hua; Dong, Shi-Hai

    2012-12-01

    The momentum representation of the Morse potential is presented analytically by hypergeometric function. The properties with respect to the momentum p and potential parameter β are studied. Note that |Ψ(p)| is a nodeless function and the mutual orthogonality of functions is ensured by the phase functions arg[Ψ(p)]. It is interesting to see that the |Ψ(p)| is symmetric with respect to the axis p = 0 and the number of wave crest of |Ψ(p)| is equal to n + 1. We also study the variation of |Ψ(p)| with respect to β. The amplitude of |Ψ(p)| first increases with the quantum number n and then deceases. Finally, we notice that the discontinuity in phase occurs at some points of the momentum p and the position and momentum probability densities are symmetric with respect to their arguments.

  15. Canadian media representations of mad cow disease.

    PubMed

    Boyd, Amanda D; Jardine, Cynthia G; Driedger, S Michelle

    2009-01-01

    A Canadian case of bovine spongiform encephalopathy (BSE) or "mad cow disease" was confirmed in May, 2003. An in-depth content analysis of newspaper articles was conducted to understand the portrayal of BSE and variant Creutzfeldt-Jakob disease (vCJD) in the Canadian media. Articles in the "first 10 days" following the initial discovery of a cow with BSE in Canada on May 20, 2003, were examined based on the premise that these initial stories provide the major frames that dominate news media reporting of the same issue over time and multiple occurrences. Subsequent confirmed Canadian cases were similarly analyzed to determine if coverage changed in these later media articles. The results include a prominence of economic articles, de-emphasis of health aspects, and anchoring the Canadian outbreak to that of Britain's crisis. The variation in media representations between those in Canada and those documented in Britain are explored in this study. PMID:19697246

  16. Holographic representation of higher spin gauge fields

    NASA Astrophysics Data System (ADS)

    Sarkar, Debajyoti; Xiao, Xiao

    2015-04-01

    Extending the results of [1,2] on the holographic representation of local gauge field operators in anti-de Sitter space, here we construct the bulk operators for higher spin gauge fields at the leading order in 1/N expansion. Working in the holographic gauge for higher spin gauge fields, we show that gauge field operators with integer spin s >1 can be represented by an integration over a ball region, which is the interior region of the spacelike bulk light cone on the boundary. The construction is shown to be anti-de Sitter covariant up to gauge transformations, and the two-point function between higher spin gauge fields and the boundary higher spin current exhibits singularities on both bulk and boundary light cones. We also comment on a possible extension to the level of three-point functions and carry out a causal construction for higher spin fields in de Sitter spacetime.

  17. Optimized spatial matrix representations of quantum Hamiltonians

    NASA Astrophysics Data System (ADS)

    Lv, Q. Z.; Jennings, D. J.; Betke, J.; Su, Q.; Grobe, R.

    2016-01-01

    We examine the accuracy of several approaches to represent the quantum mechanical Schrödinger, Klein-Gordon and Dirac Hamilton operators by optimized spatial matrices. Two of the approaches are based on periodic and reflecting boundaries and have an error scaling with the number of spatial grid points that is significantly better than the ones based on the usual approaches where the momentum operator is approximated by finite-difference schemes. These N × N matrices are optimum in the sense that their eigenvalues and eigenvectors are exact representations on the spatial grid for the continuous solutions of the corresponding force-free Hamiltonian. As an example, we apply these techniques to compute the vacuum's polarization charge density from the Dirac and Foldy-Wouthuysen theory.

  18. QRDA: Quantum Representation of Digital Audio

    NASA Astrophysics Data System (ADS)

    Wang, Jian

    2016-03-01

    Multimedia refers to content that uses a combination of different content forms. It includes two main medias: image and audio. However, by contrast with the rapid development of quantum image processing, quantum audio almost never been studied. In order to change this status, a quantum representation of digital audio (QRDA) is proposed in this paper to present quantum audio. QRDA uses two entangled qubit sequences to store the audio amplitude and time information. The two qubit sequences are both in basis state: |0> and |1>. The QRDA audio preparation from initial state |0> is given to store an audio in quantum computers. Then some exemplary quantum audio processing operations are performed to indicate QRDA's usability.

  19. LR: Compact connectivity representation for triangle meshes

    SciTech Connect

    Gurung, T; Luffel, M; Lindstrom, P; Rossignac, J

    2011-01-28

    We propose LR (Laced Ring) - a simple data structure for representing the connectivity of manifold triangle meshes. LR provides the option to store on average either 1.08 references per triangle or 26.2 bits per triangle. Its construction, from an input mesh that supports constant-time adjacency queries, has linear space and time complexity, and involves ordering most vertices along a nearly-Hamiltonian cycle. LR is best suited for applications that process meshes with fixed connectivity, as any changes to the connectivity require the data structure to be rebuilt. We provide an implementation of the set of standard random-access, constant-time operators for traversing a mesh, and show that LR often saves both space and traversal time over competing representations.

  20. New thinking, innateness and inherited representation

    PubMed Central

    Shea, Nicholas

    2012-01-01

    The New Thinking contained in this volume rejects an Evolutionary Psychology that is committed to innate domain-specific psychological mechanisms: gene-based adaptations that are unlearnt, developmentally fixed and culturally universal. But the New Thinking does not simply deny the importance of innate psychological traits. The problem runs deeper: the concept of innateness is not suited to distinguishing between the New Thinking and Evolutionary Psychology. That points to a more serious problem with the concept of innateness as it is applied to human psychological phenotypes. This paper argues that the features of recent human evolution highlighted by the New Thinking imply that the concept of inherited representation, set out here, is a better tool for theorizing about human cognitive evolution. PMID:22734066

  1. Representational momentum, centripetal force, and curvilinear impetus.

    PubMed

    Hubbard, T L

    1996-07-01

    In 3 experiments, observers witnessed a target moving along a circular orbit and indicated the location at which the target vanished. The judged vanishing point was displaced forward in the direction of implied momentum and inward in the direction of implied centripetal force. In general, increases in either the angular velocity of the target or the radius length of the orbit increased the magnitude of forward displacement. If both angular velocity and radius length were varied, then increases in either angular velocity or radius length also increased the magnitude of inward displacement. The displacement patterns were consistent with hypotheses that analogues of momentum and centripetal force were incorporated into the representational system. A framework is proposed that accounts for (a) the forward and inward displacements and (b) naive-physics data on the spiral tube problem previously interpreted as suggesting a belief in a naive curvilinear-impetus principle. PMID:8708601

  2. Cortical representation area of human dental pulp.

    PubMed

    Kubo, K; Shibukawa, Y; Shintani, M; Suzuki, T; Ichinohe, T; Kaneko, Y

    2008-04-01

    To elucidate the dental pulp-representing area in the human primary somatosensory cortex and the presence of A-beta fibers in dental pulp, we recorded somatosensory-evoked magnetic fields from the cortex in seven healthy persons using magnetoencephalography. Following non-painful electrical stimulation of the right maxillary first premolar dental pulp, short latency (27 ms) cortical responses on the magnetic waveforms were observed. However, no response was seen when stimulation was applied to pulpless teeth, such as devitalized teeth. The current source generating the early component of the magnetic fields was located anterior-inferiorly compared with the locations for the hand area in the primary somatosensory cortex. These results demonstrate the dental pulp representation area in the primary somatosensory cortex, and that it receives input from intradental A-beta neurons, providing a detailed organizational map of the orofacial area, by adding dental pulp to the classic "sensory homunculus". PMID:18362319

  3. Dependent Record Types for Dynamic Context Representation

    NASA Astrophysics Data System (ADS)

    Dapoigny, Richard; Barlatier, Patrick

    The context paradigm emerges from different areas of Artificial Intelligence (AI). However, while significative formalizations have been proposed, contexts are either mapped on independent micro-theories or considered as different concurrent viewpoints with mappings between contexts to export/import knowledge. These logical formalisms focus on the semantic level and do not take into account dynamic low-level information such as those available from sensors via physical variables. This information is a key element of contexts in pervasive computing environments. In this paper, we introduce a formal framework where the knowledge representation of context bridges the gap between semantic high-level and low-level knowledge. The logical reasoning based on intuitionistic type theory and the Curry-Howard isomorphism is able to incorporate expert knowledge as well as technical resources such as computing variable properties.

  4. Graphical representation of robot grasping quality measures

    SciTech Connect

    Varma, V.K.; Tasch, U.

    1995-03-01

    There are multiple solutions to the values of the finger forces of an object held by a multi-fingered hand. An objective function, is used in conjunction with the frictional and geometric constraints of the grasp to give a unique set of finger force values. The selection o the objective function in determining the finger forces is dependent on the type of grasp required, the material properties of the object, and the limitations of the robot fingers. In this paper several optimization functions are studied and their merits highlighted. A graphical representation of the finger force values and the objective function is introduced that enable one in selecting and comparing various grasping configurations. The impending motion of the object at different torque and finger force values are determined by observing the Normalized coefficient of friction plots.

  5. Matrix representation of the time operator

    SciTech Connect

    Bender, Carl M.; Gianfreda, Mariagiovanna

    2012-06-15

    In quantum mechanics the time operator {Theta} satisfies the commutation relation [{Theta}, H]=i, and thus it may be thought of as being formally canonically conjugate to the Hamiltonian H. The time operator associated with a given Hamiltonian H is not unique because one can replace {Theta} by {Theta}+{Theta}{sub hom}, where {Theta}{sub hom} satisfies the homogeneous condition [{Theta}{sub hom}, H]= 0. To study this nonuniqueness the matrix elements of {Theta} for the harmonic-oscillator Hamiltonian are calculated in the eigenstate basis. This calculation requires the summation of divergent series, and the summation is accomplished by using zeta-summation techniques. It is shown that by including appropriate homogeneous contributions, the matrix elements of {Theta} simplify dramatically. However, it is still not clear whether there is an optimally simple representation of the time operator.

  6. Being moved: linguistic representation and conceptual structure

    PubMed Central

    Kuehnast, Milena; Wagner, Valentin; Wassiliwizky, Eugen; Jacobsen, Thomas; Menninghaus, Winfried

    2014-01-01

    This study explored the organization of the semantic field and the conceptual structure of moving experiences by investigating German-language expressions referring to the emotional state of being moved. We used present and past participles of eight psychological verbs as primes in a free word-association task, as these grammatical forms place their conceptual focus on the eliciting situation and on the felt emotional state, respectively. By applying a taxonomy of basic knowledge types and computing the Cognitive Salience Index, we identified joy and sadness as key emotional ingredients of being moved, and significant life events and art experiences as main elicitors of this emotional state. Metric multidimensional scaling analyses of the semantic field revealed that the core terms designate a cluster of emotional states characterized by low degrees of arousal and slightly positive valence, the latter due to a nearly balanced representation of positive and negative elements in the conceptual structure of being moved. PMID:25404924

  7. New Representations of the Perturbative S Matrix.

    PubMed

    Baadsgaard, Christian; Bjerrum-Bohr, N E J; Bourjaily, Jacob L; Caron-Huot, Simon; Damgaard, Poul H; Feng, Bo

    2016-02-12

    We propose a new framework to represent the perturbative S matrix which is well defined for all quantum field theories of massless particles, constructed from tree-level amplitudes and integrable term by term. This representation is derived from the Feynman expansion through a series of partial fraction identities, discarding terms that vanish upon integration. Loop integrands are expressed in terms of "Q-cuts" that involve both off-shell and on-shell loop momenta, defined with a precise contour prescription that can be evaluated by ordinary methods. This framework implies recent results found in the scattering equation formalism at one loop, and it has a natural extension to all orders--even nonplanar theories without well-defined forward limits or good ultraviolet behavior. PMID:26918978

  8. Color demosaicking via robust adaptive sparse representation

    NASA Astrophysics Data System (ADS)

    Huang, Lili; Xiao, Liang; Chen, Qinghua; Wang, Kai

    2015-09-01

    A single sensor camera can capture scenes by means of a color filter array. Each pixel samples only one of the three primary colors. We use a color demosaicking (CDM) technique to produce full color images and propose a robust adaptive sparse representation model for high quality CDM. The data fidelity term is characterized by l1 norm to suppress the heavy-tailed visual artifacts with an adaptively learned dictionary, while the regularization term is encouraged to seek sparsity by forcing sparse coding close to its nonlocal means to reduce coding errors. Based on the classical quadratic penalty function technique in optimization and an operator splitting method in convex analysis, we further present an effective iterative algorithm to solve the variational problem. The efficiency of the proposed method is demonstrated by experimental results with simulated and real camera data.

  9. Sparse representation for color image restoration.

    PubMed

    Mairal, Julien; Elad, Michael; Sapiro, Guillermo

    2008-01-01

    Sparse representations of signals have drawn considerable interest in recent years. The assumption that natural signals, such as images, admit a sparse decomposition over a redundant dictionary leads to efficient algorithms for handling such sources of data. In particular, the design of well adapted dictionaries for images has been a major challenge. The K-SVD has been recently proposed for this task and shown to perform very well for various grayscale image processing tasks. In this paper, we address the problem of learning dictionaries for color images and extend the K-SVD-based grayscale image denoising algorithm that appears in. This work puts forward ways for handling nonhomogeneous noise and missing information, paving the way to state-of-the-art results in applications such as color image denoising, demosaicing, and inpainting, as demonstrated in this paper. PMID:18229804

  10. Structured representation for requirements and specifications

    NASA Technical Reports Server (NTRS)

    Cohen, Gerald C.; Fisher, Gene; Frincke, Deborah; Wolber, Dave

    1991-01-01

    This document was generated in support of NASA contract NAS1-18586, Design and Validation of Digital Flight Control Systems suitable for Fly-By-Wire Applications, Task Assignment 2. Task 2 is associated with a formal representation of requirements and specifications. In particular, this document contains results associated with the development of a Wide-Spectrum Requirements Specification Language (WSRSL) that can be used to express system requirements and specifications in both stylized and formal forms. Included with this development are prototype tools to support the specification language. In addition a preliminary requirements specification methodology based on the WSRSL has been developed. Lastly, the methodology has been applied to an Advanced Subsonic Civil Transport Flight Control System.

  11. Representation of psychosomatic disturbances: metaphor and metonymy.

    PubMed

    Carta, I; Clerici, M; Pantò, C; Papa, R; Cazzullo, C L

    1986-01-01

    The purpose of this study was to explore the expressive capacities of our psychosomatic patients. We invited them to represent their illness in a drawing through the design test. Following this, we investigated 43 patients affected with bronchial asthma, 30 patients affected with refractory massive obesity and compared them with a control group of 25 'normal' subjects (medical students in a situation where stress and anxiety were strongly suspected as they were awaiting to sit for an examination in the Medical School). The two patient groups showed quite relevant differences as to their own expressive modalities in the use of metaphor and metonymy, which are considered as the graphic representation means of the illness. PMID:3628685

  12. Quantum-like Representation of Bayesian Updating

    NASA Astrophysics Data System (ADS)

    Asano, Masanari; Ohya, Masanori; Tanaka, Yoshiharu; Khrennikov, Andrei; Basieva, Irina

    2011-03-01

    Recently, applications of quantum mechanics to coginitive psychology have been discussed, see [1]-[11]. It was known that statistical data obtained in some experiments of cognitive psychology cannot be described by classical probability model (Kolmogorov's model) [12]-[15]. Quantum probability is one of the most advanced mathematical models for non-classical probability. In the paper of [11], we proposed a quantum-like model describing decision-making process in a two-player game, where we used the generalized quantum formalism based on lifting of density operators [16]. In this paper, we discuss the quantum-like representation of Bayesian inference, which has been used to calculate probabilities for decision making under uncertainty. The uncertainty is described in the form of quantum superposition, and Bayesian updating is explained as a reduction of state by quantum measurement.

  13. Machine learning of user profiles: Representational issues

    SciTech Connect

    Bloedorn, E.; Mani, I.; MacMillan, T.R.

    1996-12-31

    As more information becomes available electronically, tools for finding information of interest to users becomes increasingly important. The goal of the research described here is to build a system for generating comprehensible user profiles that accurately capture user interest with minimum user interaction. The research described here focuses on the importance of a suitable generalization hierarchy and representation for learning profiles which are predictively accurate and comprehensible. In our experiments we evaluated both traditional features based on weighted term vectors as well as subject features corresponding to categories which could be drawn from a thesaurus. Our experiments, conducted in the context of a content-based profiling system for on-line newspapers on the World Wide Web (the IDD News Browser), demonstrate the importance of a generalization hierarchy and the promise of combining natural language processing techniques with machine learning (ML) to address an information retrieval (ER) problem.

  14. Morphological representation in an endangered, polysynthetic language.

    PubMed

    Rice, Sally; Libben, Gary; Derwing, Bruce

    2002-01-01

    This article presents the results from an initial psycholinguistic study of patterns of morphological representation in Dene Suliné (Chipewyan), an indigenous and highly endangered language spoken in Northwestern Canada. Our investigation focused on how morphological knowledge in this polysynthetic language is affected across various levels of language attrition by employing a morphological segmentation task and an off-line lexical decision task. We discuss the manner in which these tasks target different aspects of morphological ability and then turn to methodological issues associated with conducting psycholinguistic studies with language users that differ in levels of age, education, literacy, and bilingualism (Dene- English). Finally, we report on the challenges of doing psycholinguistic research outside the confines of a university setting and make some recommendations to other researchers who might wish to undertake similar studies. PMID:12081415

  15. Geosites and geoheritage representations - a cartographic approach

    NASA Astrophysics Data System (ADS)

    Rocha, Joao; Brilha, José

    2016-04-01

    In recent years, the increasing awareness of the importance of nature conservation, particularly towards the protection, conservation and promotion of geological sites, has resulted in a wide range of scientific studies. In a certain way, the majority of geodiversity studies, geoconservation strategies and geosites inventories and geoheritage assessment projects will use, on a particular stage, a cartographic representation - a map - of the most relevant geological and geomorphological features within the area of analyses. A wide range of geosite maps and geological heritage maps have been produced but, so far, a widely accepted conceptual cartographic framework with a specific symbology for cartographic representation has not been created. In this work we debate the lack of a systematic and conceptual framework to support geoheritage and geosite mapping. It is important to create a widely accepted conceptual cartographic framework with a specific symbology to be used within maps dedicated to geoheritage and geosites. We propose a cartographic approach aiming the conceptualization and the definition of a nomenclature and symbology system to be used on both geosite and geoheritage maps. We define a symbology framework for geosite and geoheritage mapping addressed to general public and to secondary school students, in order to be used as geotouristic and didactic tools, respectively. Three different approaches to support the definition of the symbology framework were developed: i) symbols to correlate geosites with the geological time scale; ii) symbols related to each one of the 27 geological frameworks defined in the Portuguese geoheritage inventory; iii) symbols to represent groups of geosites that share common geological and geomorphological features. The use of these different symbols in a map allows a quick understanding of a set of relevant information, in addition to the usual geographical distribution of geosites in a certain area.

  16. A Geometric Representation of Collective Attention Flows

    PubMed Central

    Shi, Peiteng; Huang, Xiaohan; Wang, Jun; Zhang, Jiang; Deng, Su; Wu, Yahui

    2015-01-01

    With the fast development of Internet and WWW, “information overload” has become an overwhelming problem, and collective attention of users will play a more important role nowadays. As a result, knowing how collective attention distributes and flows among different websites is the first step to understand the underlying dynamics of attention on WWW. In this paper, we propose a method to embed a large number of web sites into a high dimensional Euclidean space according to the novel concept of flow distance, which both considers connection topology between sites and collective click behaviors of users. With this geometric representation, we visualize the attention flow in the data set of Indiana university clickstream over one day. It turns out that all the websites can be embedded into a 20 dimensional ball, in which, close sites are always visited by users sequentially. The distributions of websites, attention flows, and dissipations can be divided into three spherical crowns (core, interim, and periphery). 20% popular sites (Google.com, Myspace.com, Facebook.com, etc.) attracting 75% attention flows with only 55% dissipations (log off users) locate in the central layer with the radius 4.1. While 60% sites attracting only about 22% traffics with almost 38% dissipations locate in the middle area with radius between 4.1 and 6.3. Other 20% sites are far from the central area. All the cumulative distributions of variables can be well fitted by “S”-shaped curves. And the patterns are stable across different periods. Thus, the overall distribution and the dynamics of collective attention on websites can be well exhibited by this geometric representation. PMID:26325390

  17. Obscurant representation for realistic IR simulation

    NASA Astrophysics Data System (ADS)

    Gozard, Patrick; Le Goff, Alain; Cathala, Thierry; Latger, Jean; Boudet, Antoine

    2003-09-01

    Obscurant representation is a key component of ground battlefield simulation, especially in the infrared domain. Obscurant are special counter measures (clouds) classically used to hide armored vehicles and deceive threatens. Obscurants are very difficult to represent especially because of multi diffusion effects of hot particles and smoke, but this representation is very important to quantify the efficiency of the decoy. This article describes a new model being involved in the simulation workshop CHORALE of the French MoD. The simulation workshop CHORALE developed in collaboration with OKTAL SE company is used by government services and industrial companies for weapon system validation and qualification trials in the infrared domain. The main operational reference for CHORALE is the assessment of the infrared guidance system of the Storm Shadow missile French version, called Scalp. This new model, integrated in CHORALE, enables to simulate the emitted radiance and the transmission of any pre computed obscurant cloud in the virtual battlefield. In the modeling step, the cloud is defined by a set of "voxels" (elementary volume elements). Each voxel contains the spectral extinction coefficient and the spectral scattering coefficients. The shape, i.e. the voxels content, is changing with time to convey the dynamic evolution of the obscurant. In the Non Real Time rendering step, primary rays are traced inside the clouds. For each voxel, scattering rays are then traced to their neighboring voxels and the local hot sources. Actually, ray tracing is used to solve the Radiative Transfer Equation. The main advantage is to be able to solve it taking into account the synthetic environment: the local terrain, the target hidden in the cloud, the atmospheric and weather conditions. The main originality is the multithreading ray tracing which enables to tackle huge quantities of rays in complex geometric environment.

  18. Temperature representation in the Drosophila brain

    PubMed Central

    Frank, Dominic D.; Jouandet, Genevieve C.; Kearney, Patrick J.; Macpherson, Lindsey J.; Gallio, Marco

    2015-01-01

    SUMMARY In Drosophila, rapid temperature changes are detected at the periphery by dedicated receptors forming a simple sensory map for hot and cold in the brain1. However, flies show a host of complex innate and learned responses to temperature, indicating that they are able to extract a range of information from this simple input. Here, we define the anatomical and physiological repertoire for temperature representation in the Drosophila brain. First, we use a photolabeling strategy2 to trace the connections that relay peripheral thermosensory information to higher brain centers, and show that they largely converge onto three target regions: the Mushroom Body, Lateral Horn (well-known centers for sensory processing) and the Posterior Lateral Protocerebrum, a region we now define as a major site of thermosensory representation. Then, using in vivo calcium imaging3, we describe the thermosensory projection neurons selectively activated by hot or cold stimuli. Fast-adapting neurons display transient “ON” and “OFF” responses and track rapid temperature shifts remarkably well, while slow-adapting cell responses better reflect the magnitude of simple thermal changes. Unexpectedly, we also find a population of ‘broadly-tuned’ cells that respond to both heating and cooling, and show that they are required for normal behavioral avoidance of both hot and cold in a simple 2-choice temperature preference assay. Taken together, our results uncover a coordinated ensemble of neural responses to temperature in the fly brain, demonstrate that a broadly tuned thermal-line contributes to rapid avoidance behavior, and illustrate how stimulus quality, temporal structure, and intensity can be extracted from a simple glomerular map at a single synaptic station. PMID:25739506

  19. A Geometric Representation of Collective Attention Flows.

    PubMed

    Shi, Peiteng; Huang, Xiaohan; Wang, Jun; Zhang, Jiang; Deng, Su; Wu, Yahui

    2015-01-01

    With the fast development of Internet and WWW, "information overload" has become an overwhelming problem, and collective attention of users will play a more important role nowadays. As a result, knowing how collective attention distributes and flows among different websites is the first step to understand the underlying dynamics of attention on WWW. In this paper, we propose a method to embed a large number of web sites into a high dimensional Euclidean space according to the novel concept of flow distance, which both considers connection topology between sites and collective click behaviors of users. With this geometric representation, we visualize the attention flow in the data set of Indiana university clickstream over one day. It turns out that all the websites can be embedded into a 20 dimensional ball, in which, close sites are always visited by users sequentially. The distributions of websites, attention flows, and dissipations can be divided into three spherical crowns (core, interim, and periphery). 20% popular sites (Google.com, Myspace.com, Facebook.com, etc.) attracting 75% attention flows with only 55% dissipations (log off users) locate in the central layer with the radius 4.1. While 60% sites attracting only about 22% traffics with almost 38% dissipations locate in the middle area with radius between 4.1 and 6.3. Other 20% sites are far from the central area. All the cumulative distributions of variables can be well fitted by "S"-shaped curves. And the patterns are stable across different periods. Thus, the overall distribution and the dynamics of collective attention on websites can be well exhibited by this geometric representation. PMID:26325390

  20. Conformal field theories, representations and lattice constructions

    NASA Astrophysics Data System (ADS)

    Dolan, L.; Goddard, P.; Montague, P.

    1996-07-01

    An account is given of the structure and representations of chiral bosonic meromorphic conformal field theories (CFT's), and, in particular, the conditions under which such a CFT may be extended by a representation to form a new theory. This general approach is illustrated by considering the untwisted and Z 2-twisted theories, ℋ( Λ) andtilde H(Λ ) respectively, which may be constructed from a suitable even Euclidean lattice Λ. Similarly, one may construct latticesΛ _C andtilde Λ _C by analogous constructions from a doubly-even binary codeC. In the case whenC is self-dual, the corresponding lattices are also. Similarly, ℋ( Λ) andtilde H(Λ ) are self-dual if and only if Λ is. We show thatH(Λ _C ) has a natural “triality” structure, which induces an isomorphismH(tilde Λ _C ) ≡tilde H(Λ _C ) and also a triality structure ontilde H(tilde Λ _C ). ForC the Golay code,tilde Λ _C is the Leech lattice, and the triality ontilde H(tilde Λ _C ) is the symmetry which extends the natural action of (an extension of) Conway's group on this theory to the Monster, so setting triality and Frenkel, Lepowsky and Meurman's construction of the natural Monster module in a more general context. The results also serve to shed some light on the classification of self-dual CFT's. We find that of the 48 theories ℋ( Λ) andtilde H(Λ ) with central charge 24 that there are 39 distinct ones, and further that all 9 coincidences are accounted for by the isomorphism detailed above, induced by the existence of a doubly-even self-dual binary code.

  1. Hand specific representations in language comprehension.

    PubMed

    Moody-Triantis, Claire; Humphreys, Gina F; Gennari, Silvia P

    2014-01-01

    Theories of embodied cognition argue that language comprehension involves sensory-motor re-enactments of the actions described. However, the degree of specificity of these re-enactments as well as the relationship between action and language remains a matter of debate. Here we investigate these issues by examining how hand-specific information (left or right hand) is recruited in language comprehension and action execution. An fMRI study tested self-reported right-handed participants in two separate tasks that were designed to be as similar as possible to increase sensitivity of the comparison across task: an action execution go/no-go task where participants performed right or left hand actions, and a language task where participants read sentences describing the same left or right handed actions as in the execution task. We found that language-induced activity did not match the hand-specific patterns of activity found for action execution in primary somatosensory and motor cortex, but it overlapped with pre-motor and parietal regions associated with action planning. Within these pre-motor regions, both right hand actions and sentences elicited stronger activity than left hand actions and sentences-a dominant hand effect. Importantly, both dorsal and ventral sections of the left pre-central gyrus were recruited by both tasks, suggesting different action features being recruited. These results suggest that (a) language comprehension elicits motor representations that are hand-specific and akin to multimodal action plans, rather than full action re-enactments; and (b) language comprehension and action execution share schematic hand-specific representations that are richer for the dominant hand, and thus linked to previous motor experience. PMID:24917803

  2. Mapping phantom movement representations in the motor cortex of amputees.

    PubMed

    Mercier, Catherine; Reilly, Karen T; Vargas, Claudia D; Aballea, Antoine; Sirigu, Angela

    2006-08-01

    Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a phantom limb endowed with sensory and motor qualities. How can cortical reorganization after amputation be reconciled with the maintenance of a motor representation of the phantom limb in the brain? In an attempt to answer this question we explored the relationship between the cortical representation of the remaining arm muscles and that of phantom movements. Using transcranial magnetic stimulation (TMS) we systematically mapped phantom movement perceptions while simultaneously recording stump muscle activity in three above-elbow amputees. TMS elicited sensations of movement in the phantom hand when applied over the presumed hand area of the motor cortex. In one subject the amplitude of the perceived movement was positively correlated with the intensity of stimulation. Interestingly, phantom limb movements that the patient could not produce voluntarily were easily triggered by TMS, suggesting that the inability to voluntarily move the phantom is not equivalent to a loss of the corresponding movement representation. We suggest that hand movement representations survive in the reorganized motor area of amputees even when these cannot be directly accessed. The activation of these representations is probably necessary for the experience of phantom movement. PMID:16844715

  3. 22 CFR 145.17 - Certifications and representations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Certifications and representations. 145.17 Section 145.17 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Pre-Award Requirements § 145.17 Certifications and representations....

  4. Students' Difficulties With Multiple Representations in Introductory Mechanics

    ERIC Educational Resources Information Center

    Nguyen, Dong-Hai; Rebello, N. Sanjay

    2011-01-01

    Research in physics education indicates that the use of multiple representations in teaching and learning helps students become better problem-solvers. We report on a study to investigate students' difficulties in solving mechanics problems presented in multiple representations. We conducted teaching/learning interviews with 20 students in a…

  5. Height Differences in English Dialects: Consequences for Processing and Representation

    ERIC Educational Resources Information Center

    Scharinger, Mathias; Lahiri, Aditi

    2010-01-01

    This study examines the role of abstractness during the activation of a lexical representation. Abstractness and conflict are directly modeled in our approach by invoking lexical representations in terms of contrastive phonological features. In two priming experiments with English nouns differing only in vowel height of their stem vowels (e.g.,…

  6. Uncovering Mental Representations with Markov Chain Monte Carlo

    ERIC Educational Resources Information Center

    Sanborn, Adam N.; Griffiths, Thomas L.; Shiffrin, Richard M.

    2010-01-01

    A key challenge for cognitive psychology is the investigation of mental representations, such as object categories, subjective probabilities, choice utilities, and memory traces. In many cases, these representations can be expressed as a non-negative function defined over a set of objects. We present a behavioral method for estimating these…

  7. Learning with Multiple Representations: Extending Multimedia Learning beyond the Lab

    ERIC Educational Resources Information Center

    Eilam, Billie; Poyas, Yael

    2008-01-01

    The present study extended multimedia learning principles beyond the lab to an ecologically valid setting (homework). Eighteen information cards were used to perform three homework tasks. The control group students learned from single representation (SR) cards that presented all information as printed text. The multiple representation (MR) group…

  8. 12 CFR 268.605 - Representation and official time.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Representation and official time. 268.605... Representation and official time. (a) At any stage in the processing of a complaint, including the counseling... or she shall have a reasonable amount of official time, if otherwise on duty, to prepare...

  9. 12 CFR 268.605 - Representation and official time.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Representation and official time. 268.605... Representation and official time. (a) At any stage in the processing of a complaint, including the counseling... or she shall have a reasonable amount of official time, if otherwise on duty, to prepare...

  10. 12 CFR 268.605 - Representation and official time.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Representation and official time. 268.605... Representation and official time. (a) At any stage in the processing of a complaint, including the counseling... or she shall have a reasonable amount of official time, if otherwise on duty, to prepare...

  11. Attachment Representations and Characteristics of Friendship Relations during Adolescence

    ERIC Educational Resources Information Center

    Zimmermann, Peter

    2004-01-01

    Attachment theory proposes that experiences with the primary caregivers are an important basis for the development of close social relationships outside the parent-child relationship. This study examined the association between representations of attachment, as assessed with the Adult Attachment Interview (AAI), representations of friendship and…

  12. Drawing Connections across Conceptually Related Visual Representations in Science

    ERIC Educational Resources Information Center

    Hansen, Janice

    2013-01-01

    This dissertation explored beliefs about learning from multiple related visual representations in science, and compared beliefs to learning outcomes. Three research questions were explored: 1) What beliefs do pre-service teachers, non-educators and children have about learning from visual representations? 2) What format of presenting those…

  13. Representation of Numerical and Non-Numerical Order in Children

    ERIC Educational Resources Information Center

    Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

    2012-01-01

    The representation of numerical and non-numerical ordered sequences was investigated in children from preschool to grade 3. The child's conception of how sequence items map onto a spatial scale was tested using the Number-to-Position task (Siegler & Opfer, 2003) and new variants of the task designed to probe the representation of the alphabet…

  14. 8 CFR 1292.1 - Representation of others.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... violation of the provisions of 28 CFR 45.735-7. (d) Amicus curiae. The Board may grant permission to appear... 1292.1 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS REPRESENTATION AND APPEARANCES § 1292.1 Representation of others. (a) A...

  15. Black Representation on Central City School Boards Revisited.

    ERIC Educational Resources Information Center

    Robinson, Ted; And Others

    1981-01-01

    This article is an extension of Welch and Karnig's (1978) school board study analyzing Black representation. The sample size was increased from the original 43 to 75 central cities. Unlike Welch and Karnig, new results showed that at-large electoral systems significantly reduce proportionally based equitable Black representation. (Author/AM)

  16. Language, Perception, and the Schematic Representation of Spatial Relations

    ERIC Educational Resources Information Center

    Amorapanth, Prin; Kranjec, Alexander; Bromberger, Bianca; Lehet, Matthew; Widick, Page; Woods, Adam J.; Kimberg, Daniel Y.; Chatterjee, Anjan

    2012-01-01

    Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual…

  17. Studying Action Representation in Children via Motor Imagery

    ERIC Educational Resources Information Center

    Gabbard, Carl

    2009-01-01

    The use of motor imagery is a widely used experimental paradigm for the study of cognitive aspects of action planning and control in adults. Furthermore, there are indications that motor imagery provides a window into the process of action representation. These notions complement internal model theory suggesting that such representations allow…

  18. Generating Cognitive Dissonance in Student Interviews through Multiple Representations

    ERIC Educational Resources Information Center

    Linenberger, Kimberly J.; Bretz, Stacey Lowery

    2012-01-01

    This study explores what students understand about enzyme-substrate interactions, using multiple representations of the phenomenon. In this paper we describe our use of the 3 Phase-Single Interview Technique with multiple representations to generate cognitive dissonance within students in order to uncover misconceptions of enzyme-substrate…

  19. Adults Performing Children: Ideology, Representation, and the Construction of "Real."

    ERIC Educational Resources Information Center

    Van de Water, Manon

    2003-01-01

    Defines ideology and representation as manifested in the field of theatre for youth. Discusses these theoretical constructs as they relate to practice in the field. Concludes that the field of theatre for young audiences is under-theorized. Hopes that the symposium has made participants more aware of the role of ideology, representation, and…

  20. Making Implicit Multivariable Calculus Representations Explicit: A Clinical Study

    ERIC Educational Resources Information Center

    McGee, Daniel; Moore-Russo, Deborah; Martinez-Planell, Rafael

    2015-01-01

    Reviewing numerous textbooks, we found that in both differential and integral calculus textbooks the authors commonly assume that: (i) students can generalize associations between representations in two dimensions to associations between representations of the same mathematical concept in three dimensions on their own; and (ii) explicit…