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)
Representation is representation of similarities.
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
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…
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
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…
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.
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…
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.…
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…
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.
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.
Umbra's system representation.
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.
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…
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…
[Time perceptions and representations].
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
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)
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.
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.
Naturalising Representational Content
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
Naturalising Representational Content.
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
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.
Supramodal representation of emotions.
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
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.
Mental Representations of Weekdays
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
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.
Computer aided surface representation
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.
Sparse representation with kernels.
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
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.
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.
Parental representations of transsexuals.
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
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.
Computer aided surface representation
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.
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…
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…
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…
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…
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…
Revealing children's implicit spelling representations.
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
A generalized wavelet extrema representation
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.
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…
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
Computer aided surface representation
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.
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.
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.
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.
Computer representation of molecular surfaces
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.
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.
Texture Representations Using Subspace Embeddings
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
Texture Representations Using Subspace Embeddings.
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
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.
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…
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.
Culture as shared cognitive representations.
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
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.
Active maintenance of semantic representations.
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
Representation of Ideal Magnetohydrodynamic Modes
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
Assessing value representation in animals.
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
Social representations of female orgasm.
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
Learning multiple layers of representation.
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
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?
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…
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…
Lie antialgebras: cohomology and representations
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.
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…
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.
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…
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…
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.
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.
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.
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.
Representations of mad cow disease.
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
Representations to support terrain reasoning
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.
Time representations in social science
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
Free boundary ballooning mode representation
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.
SAR Image Complex Pixel Representations
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.
Temporal Representation in Semantic Graphs
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.
Computational representation of biological systems
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.
Fock representation for quaternion fields
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.
Representation of ideal magnetohydrodynamic modes
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.
Body representations and brain damage.
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
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.
Neural Representations of Physics Concepts.
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
Representations of metabolic knowledge: pathways.
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
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.
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.
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...
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...
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…
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…
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…
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…
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…
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,…
Alternative Approach to Nuclear Data Representation
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.
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.
Neural representation of probabilistic information.
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
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.
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.
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.
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
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
Spatial Representation of Ordinal Information.
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
Spatial Representation of Ordinal Information
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
Visual representations of Iranian transgenders.
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
Representation and Re-Presentation in Litigation Science
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
Extended loop representation of quantum gravity
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.
Braid group representation on quantum computation
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.
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.
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.
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.
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.
Wavelet Representation of Contour Sets
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.
Updating representations of temporal intervals.
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
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…
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...
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...
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...
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...
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...
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…
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…
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…
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…
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.
Efficient online bootstrapping of sensory representations.
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
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…
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…
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....
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....
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…
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.
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…
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…
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…
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…
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.…
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,…
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…
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…
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…
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…
Representable states on quasilocal quasi *-algebras
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.
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…
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....
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....
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....
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…
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.
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...
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..
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)…
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.…
Continuum representations of cellular solids
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.
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.
Representation of probabilistic scientific knowledge
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
Spatially variant morphological restoration and skeleton representation.
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
Phase space representation of quantum dynamics
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.
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.
Knowledge representation techniques for seismic signal understanding
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)
General Regression and Representation Model for Classification
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
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.
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…
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.
Sparse representation of complex MRI images.
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
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.
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.
Death representation of caregivers in hospice.
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
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.
Minimal representations, geometric quantization, and unitarity.
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
Dispersive approaches for three-particle final state interaction
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.
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...
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…
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.
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.
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....
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....
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.
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...
2-Group Representations for Spin Foams
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.
Mental Representations Formed From Educational Website Formats
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.
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.
Interactive information retrieval systems with minimalist representation
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.
Representation and perception of scenic layout.
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
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.
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.
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.
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.
Seismic-source representation for spall
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.
The Representation and Parametrization of Orthogonal Matrices.
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
The Representation of Polysemy: MEG Evidence
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
Exploring the Structure of Spatial Representations.
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
Mental representation and motor imagery training
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
Exploring the Structure of Spatial Representations
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
Spinor representations of affine Lie algebras
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
The representation of polysemy: MEG evidence.
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
Mental representation and motor imagery training.
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
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…
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.…
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
In defense of abstract conceptual representations.
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
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.
A-Optimal Projection for Image Representation.
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
Biologically Plausible, Human-Scale Knowledge Representation.
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
Action simulation: time course and representational mechanisms
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
Negation in the brain: modulating action representations.
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
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.
The interaction of representation and reasoning
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
Natural geometric representation for electron local observables
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.
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.
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…
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…
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…
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…
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…
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…
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.
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 =…
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.
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).
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.
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.
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.
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.
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.
Context representation and fusion: advancements and opportunities.
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
Context Representation and Fusion: Advancements and Opportunities
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
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).
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.
Evaluating illness representations in heart transplant patients.
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
Human spatial representation: insights from animals.
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
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.
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.
The Feynman-Schwinger representation in QCD
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.
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.
[The fragmentation of representational space in schizophrenia].
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
Building Hierarchical Representations for Oracle Character and Sketch Recognition.
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
Social representations and normative beliefs of aging.
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
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…
Conceptual size representation in ventral visual cortex.
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
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…
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 §...
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…
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...
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...
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...
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...
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...
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…
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...